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The hydraulic conductivity and adsorptivity of clay barrier materials containing organoclay Denham, William T. 1999

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THE HYDRAULIC CONDUCTIVITY AND ADSORPTIVITY OF CLAY BARRIER MATERIALS CONTAINING ORGANOCLAY b y WILLIAM T. DENHAM B . S c . (Agr icu l ture) , U n i v e r s i t y o f B r i t i s h C o l u m b i a , 1995 A T H E S I S S U B M I T T E D I N P A R T I A L F U L F I L L M E N T O F T H E R E Q U I R E M E N T S F O R T H E D E G R E E O F M A S T E R O F A P P L I E D S C I E N C E i n T H E F A C U L T Y O F G R A D U A T E S T U D I E S D E P A R T M E N T O F C I V I L E N G I N E E R I N G W e accept this thesis as c o n f o r m i n g to the required standard T H E U N I V E R S I T Y O F B R I T I S H C O L U M B I A February, 1999 © W i l l i a m T . D e n h a m , 1999 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department of (g/l/ (^T/U 6 &flX?J& The University of British Columbia Vancouver, Canada Date DE-6 (2/88) ABSTRACT T h i s study investigated the h y d r a u l i c conduct iv i ty (k) and adsorptivi ty o f s imulated c l a y barrier material w h i c h contained organoclay, for the purpose o f d iscover ing i f the i n c l u s i o n o f organoclay i n c lay barrier material c o u l d effectively i m m o b i l i z e inorganic contaminants. T h e organoclay was produced us ing s o d i u m bentonite and the cat ionic surfactant h e x a d e c y l t r i m e t h y l a m m o n i u m ( H D T M A ) . T h e test chemicals used to investigate k and adsorptivi ty were pentachlorophenol ( P C P ) , naphthalene ( N P ) , toluene ( T L ) , and m e t h y l ethyl ketone ( M E K ) . B a t c h adsorption tests us ing the test chemicals i n di lute concentrations were performed o n bentonite and organoclay. C l a y barrier materials were produced w i t h bentonite, organoclay, and sand. These c l a y barrier materials were compacted, p laced i n a r i g i d - w a l l permeameter, and permeated w i t h 0.01 M CaS0 4 or 0.01 M C a C l 2 , and also w i t h di lute solutions o f the test chemicals . A i r pressure was used to create hydraul ic head through the permeameter, and k o f the c l a y barrier materials w i t h and without organoclay was determined. T h e effluent f r o m the permeameter was col lected and analyzed for the test chemicals . Resul ts f r o m the batch adsorption tests indicated that organoclay was m u c h m o r e effective than bentonite i n adsorbing P C P , N P and T L f r o m a di lute aqueous so lut ion. These three chemicals are sparing soluble i n water. N e i t h e r organoclay nor bentonite effect ively adsorbed M E K , the o n l y test c h e m i c a l i n the study that was h i g h l y soluble i n water. H o w e v e r , organoclay d i d adsorb more M E K than bentonite. O r g a n o c l a y was s h o w n to have a signif icant effect o n k i n the c lay barrier materials , a lways increasing k as compared to c lay barrier material w h i c h d i d not conta in organoclay. There was also a considerable interaction between k, organoclay, and the test chemica ls . N P and T L caused a large increase i n k i n the c lay barrier materials containing organoclay, and M E K caused a decrease. T h i s interaction, though present, was not as p r o n o u n c e d i n the c l a y barrier materials w h i c h d i d not contain organoclay. Test ing o f the effluent i n the permeameter tests showed that c lay barrier materials conta in ing organoclay retained P C P m u c h better than c lay barrier materials wi thout organoclay. H o w e v e r , the retention o f P C P was not as great as w o u l d be predicted us ing the results o f the batch adsorpt ion tests. ACKNOWLEDGMENTS T h e author w o u l d l i k e to express his sincere gratitude and appreciat ion to: • D r . L . Y . L i , for her constant support and patience throughout the course o f this project, and also for her valuable suggestions and insights, wi thout w h i c h the study c o u l d not have been successful. • D r . L . M . L a v k u l i c h , for his assistance and advice i n carry ing out some o f the tests required for m i n e r a l o g i c a l and p h y s i c a l characterization o f the s o i l materials. • M s . P. P a r k i n s o n and M s . S. Harper , for their unt i r ing assistance and advice regarding laboratory analysis, equipment and procedures. • M r . K . N i e l s o n , for his construction o f the components necessary for the c o m p a c t i o n and permeameter apparatus, and for his valuable ideas and suggestions regarding these components. • M r . F . L i , for his assistance w i t h several o f the tests regarding p h y s i c a l and p h y s i c o c h e m i c a l characterization o f the s o i l materials, and for his comments and suggestions regarding analysis o f the data f r o m the study. • M s . L . H u i , for her assistance i n per forming several o f the batch adsorpt ion tests. TABLE OF CONTENTS A B S T R A C T A C K N O W L E D G M E N T S L I S T O F T A B L E S L I S T O F F I G U R E S C H A P T E R 1: I N T R O D U C T I O N 1 1.1 STATEMENT OF THE PROBLEM „. 1 1.2 SCOPE AND OBJECTIVES OF THE PRESENT STUDY 7 1.3 ORGANIZATION OF THESIS 8 1.4 CONTRIBUTIONS OF THIS RESEARCH 9 C H A P T E R 2: L I T E R A T U R E R E V I E W 10 2.1 ADSORPTION STUDIES WITH ORGANOCLAYS 10 2.2 HYDRAULIC CONDUCTIVITY OF ORGANOCLAYS 18 2.3 OTHER ORGANOCLAY STUDIES 20 2.4 EFFECT OF ORGANIC CHEMICALS ON CLAY HYDRAULIC CONDUCTIVITY 23 2.5 RELATIONSHIP OF PRIOR RESEARCH TO THE PRESENT STUDY 26 CHAPTER 3: MATERIALS AND METHODS 2g 3.1 SOIL MATERIALS 28 3.1.1 Origins 28 3.1.2 Physical properties 28 3.1.2.1 G r a i n size distr ibut ion 28 3.1.2.2 Spec i f i c gravity 28 3.1.2.3 Spec i f i c surface 29 3.1.2.4 Atterberg l i m i t s 29 3.1.2.5 M a x i m u m dry density and o p t i m u m water content 29 3.1.2.6 O r g a n i c carbon content 29 3.1.3 Physicochemical properties 30 3.1.3.1. p H 30 3.1.3.2 C a t i o n exchange capacity 30 3.1.4 Mineralogical properties 30 3.1.5 Preparation of organoclay 30 3.1.5.1 Organoc lay product ion 3 0 3.1.5.2 C o n f i r m a t i o n o f surfactant adsorption 31 3.1.6 Preparation of control and experimental soils 31 3.2 CHEMICALS 32 3.2.1 Hexadecyltrimethylammonium 32 3.2.2 Test chemicals 33 3.3 ADSORPTION CHARACTERISTICS 33 3.3.1 Pentachlorophenol 33 3.3.1.1 Acidic solution 34 3.3.1.2 Basic solution 36 3.3.2 Naphthalene 36 3.3.3 Toluene 36 3.3.4 Methyl ethyl ketone 37 3.4 HYDRAULIC CONDUCTIVITY TESTING 38 3.4.1 Apparatus 38 3.4.1.1 Compaction apparatus 38 3.4.1.2 Hydraulic conductivity apparatus 38 3.4.2 Compaction procedure 42 3.4.3 Hydraulic conductivity testing 43 3.4.3.1 Pentachlorophenol 45 3.4.3.2 Naphthalene 45 3.4.3.3 Toluene 45 3.4.3.4 Methyl ethyl ketone 46 3.5 EFFLUENT ANALYSIS 46 3.5.1 Pentachlorophenol 47 3.5.2 Naphthalene 47 3.5.3 Toluene 47 3.5.4 Methyl ethyl ketone 47 3.5.5 pH measurements 48 C H A P T E R 4: R E S U L T S AND DISCUSSION 49 4.1 SOIL MATERIALS 49 4.1.1 Physical properties 49 4.1.2 Physicochemical and mineralogical properties 50 4.2 ADSORPTION CHARACTERISTICS 50 4.2.1 Pentachlorophenol 50 4.2.2 Naphthalene 56 4.2.3 Toluene 58 4.2.4 Methyl ethyl ketone 58 4.3 HYDRAULIC CONDUCTIVITY TESTING 61 4.3.1 Control tests 62 4.3.2 Pentachlorophenol 64 4.3.3 Naphthalene 67 4.3.4 Toluene 67 4.3.5 Methyl ethyl ketone 71 4.4 EFFECT OF TEST CHEMICALS ON HYDRAULIC CONDUCTIVITY 71 4.4.1. Pentachlorophenol 71 4.4.2 Naphthalene 73 4.4.3 Toluene 77 4.4.4 Methyl ethyl ketone 77 4.4.5 Summary of hydraulic conductivity results 80 4.5 ADSORPTIVITY OF CLAY BARRIER MATERIAL FOR TEST CHEMICALS 81 4.5.1 Pentachlorophenol 82 4.5.2 Naphthalene 84 4.5.3 Toluene 85 4.5.4 Methyl Ethyl Ketone 85 C H A P T E R 5: CONCLUSIONS AND R E C O M M E N D A T I O N S 88 5.1 CONCLUSIONS 88 5.2 CONTRIBUTIONS TO THE GEO-ENVIRONMENTAL FIELD 90 5.3 RECOMMENDED FUTURE STUDIES 91 R E F E R E N C E S 95 APPENDICES 102 A. GRAIN SIZE ANALYSIS 102 B. SPECIFIC GRAVITY OF SOIL MATERIALS 105 C. SPECIFIC SURFACE OF BENTONITE AND ORGANOCLAY 107 D. OPTIMUM MOISTURE CONTENT AND MAXIMUM ix DRY DENSITY OF SOILS 109 E. CARBON ANALYSES OF ORGANOCLAY AND BENTONITE 112 F. SOIL AND EFFLUENT PH MEASUREMENTS 114 G . CATION EXCHANGE CAPACITY OF BENTONITE AND SAND 116 H . DETAILED GAS CHROMATOGRAPH CONDITIONS 118 I. CALCULATION OF ORGANIC CHEMICAL CONCENTRATION IN DILUTED SAMPLES . 121 J. DETAILED HYDRAULIC CONDUCTIVITY, EFFLUENT PH AND EFFLUENT CONCENTRATION TABLES 122 x LIST OF TABLES T a b l e 3.1: P h y s i c a l properties o f test chemicals 33 T a b l e 3.2: S u m m a r y o f hydraul ic conduct iv i ty runs 44 T a b l e 4.1: P h y s i c a l properties o f s o i l materials 49 T a b l e 4.2: P h y s i c o c h e m i c a l and minera log ica l properties o f s o i l materials 50 T a b l e 4.3: Results summary for h y d r a u l i c conduct iv i ty (k) tests 62 T a b l e 4.4: B r e a k t h r o u g h vo lumes for P C P runs 83 T a b l e 4.5: B r e a k t h r o u g h vo lumes for N P runs 85 T a b l e 4.6: B r e a k t h r o u g h vo lumes for M E K runs 86 Tables in Appendices T a b l e A . l : G r a i n size d is tr ibut ion o f sand, bentonite and organoclay 104 T a b l e B . 1: Results o f specif ic gravity tests 106 T a b l e C . 1: C l a y weight and moisture % o f samples used i n E G M E test 107 T a b l e C . 2 : W e i g h t readings at various times dur ing E G M E test 108 T a b l e C . 3 : A v e r a g e specif ic surface o f bentonite and organoclay 108 T a b l e D . 1: O p t i m u m moisture contents and m a x i m u m dry densities o f control and experimental soi ls 109 T a b l e E . 1: O r g a n i c carbon content o f bentonite 112 T a b l e E . 2 : O r g a n i c carbon r e m o v e d b y repeated w a s h i n g o f organoclay 113 T a b l e F . 1: S o i l materials and l i q u i d v o l u m e s used for p H measurements 114 T a b l e F . 2 : M e a s u r e d p H o f s o i l materials 115 T a b l e G . 1: C a t i o n exchange capacity o f bentonite and sand 117 LIST OF FIGURES F i g u r e 1.1: T h e hydrat ion shel l preventing adsorption o f H O C ' s o n clays 6 F i g u r e 1.2: C l a y surface m o d i f i e d by a cat ionic surfactant 6 F i g u r e 3.1: C o m p a c t i o n apparatus (assembled, side v i e w ) 39 F i g u r e 3.2: T o p v i e w o f compaction/permeameter ce l l 39 F i g u r e 3.3: A s s e m b l e d c o m p a c t i o n apparatus 4 0 F i g u r e 3.4: Compaction/permeameter c e l l 4 0 F i g u r e 3.5: T o p and bot tom c o m p a c t i o n apparatus plates 41 F i g u r e 3.6: Schematic o f permeameter system 41 F i g u r e 3.7: Permeameter apparatus i n laboratory 42 F i g u r e 4.1: G r a i n size d is tr ibut ion o f bentonite, sand and organoclay 51 F i g u r e 4.2: A d s o r p t i o n o f P C P by organoclay and bentonite at p H 4.0 51 F i g u r e 4.3: A d s o r p t i o n o f P C P by organoclay and bentonite at p H 10.0 53 F i g u r e 4.4: Poss ib le mechanisms for b o n d i n g o f anionic P C P to organoclay ... 57 F i g u r e 4.5: A d s o r p t i o n o f N P by organoclay and bentonite 59 F i g u r e 4.6: A d s o r p t i o n o f T L by organoclay and bentonite 59 F i g u r e 4.7: A d s o r p t i o n o f M E K by organoclay and bentonite 60 F i g u r e 4 .8: H y d r a u l i c conduct iv i ty o f R u n s C l , C 2 & C 3 63 F i g u r e 4.9: H y d r a u l i c conduct iv i ty o f R u n s C 4 , C 5 & C 6 63 F i g u r e 4.10: H y d r a u l i c conduct iv i ty o f R u n s E l , E 2 & E 3 65 F i g u r e 4.11: H y d r a u l i c conduct iv i ty o f R u n s E 4 , E 5 & E 6 65 F i g u r e 4.12: H y d r a u l i c conduct iv i ty o f R u n s C 7 , C 8 & C 9 66 F i g u r e 4.13: H y d r a u l i c conduct iv i ty o f R u n s C 1 0 , C11 & C 1 2 66 xii F i g u r e 4.14: H y d r a u l i c conduct iv i ty o f R u n s E 7 , E 8 & E 9 68 F i g u r e 4.15: H y d r a u l i c conduct iv i ty o f R u n s E 1 0 , E l 1 & E 1 2 68 F i g u r e 4.16: H y d r a u l i c conduct iv i ty o f R u n s C 1 3 - C 1 9 69 F i g u r e 4.17: H y d r a u l i c conduct iv i ty o f R u n s E l 3-E21 69 F i g u r e 4.18: H y d r a u l i c conduct iv i ty o f R u n s C 2 0 , C 2 1 & C 2 2 70 F i g u r e 4.19: H y d r a u l i c conduct iv i ty o f R u n s E 2 2 , E 2 3 & E 2 4 70 F i g u r e 4 .20: H y d r a u l i c conduct iv i ty o f R u n s C 2 3 , C 2 4 & C 2 5 72 F i g u r e 4.21: H y d r a u l i c conduct iv i ty o f R u n s E 2 5 - E 3 0 72 F i g u r e 4.22: H y d r a u l i c conduct iv i ty o f R u n s C 1 3 , C 1 4 & C 1 5 74 F i g u r e 4.23: V a r i a t i o n i n [ N P ] w i t h t ime for R u n s C 1 3 , C 1 4 & C l 5 74 F i g u r e 4.24: H y d r a u l i c conduct iv i ty o f R u n s E 1 0 , E l 1 & E 1 2 75 F i g u r e 4.25: H y d r a u l i c conduct iv i ty o f R u n s E 1 3 , E 1 4 & E 1 5 75 F i g u r e 4.26: H y d r a u l i c conduct iv i ty o f R u n s E 1 6 , E 1 7 & E 1 8 76 F i g u r e 4.27: H y d r a u l i c conduct iv i ty o f R u n s E 2 5 , E 2 6 & E 2 8 87 F i g u r e 4 .28: [ M E K ] for R u n s E 2 5 & E 2 8 87 Figures in Appendix D F i g u r e D . l : C o m p a c t i o n curve for s o i l #1 110 F i g u r e D . 2 : C o m p a c t i o n curve for s o i l # 2 110 F i g u r e D . 3 : C o m p a c t i o n curve for so i l # 3 I l l F i g u r e D . 4 : C o m p a c t i o n curve for s o i l # 4 I l l xiii C H A P T E R 1 I N T R O D U C T I O N 1.1 S T A T E M E N T O F T H E P R O B L E M There are m a n y organic chemicals produced by society that are very useful , but w h i c h are also potent ia l ly t o x i c to biota. F o u r o f the chemicals w h i c h are w i d e l y used and w h i c h pose environmenta l danger are pentachlorophenol ( P C P ) , naphthalene ( N P ) , toluene ( T L ) , and m e t h y l ethyl ketone ( M E K ) . I f use o f these and other tox ic organic chemicals is to continue, d isposal methods must be found w h i c h ensure m i n i m a l or no damage to the environment and/or h u m a n populat ions. P C P was one o f the most w i d e l y - u s e d biocides i n the U n i t e d States, found i n w o o d preservatives, insecticides and herbicides avai lable for home and garden use. It is no longer f o u n d i n these products, but is s t i l l i n use as a w o o d preservative for p o w e r l i n e poles, ra i l road ties, cross arms, and fence posts. It has been found i n at least 260 o f the N a t i o n a l Pr ior i t ies L i s t sites ident i f ied b y the U n i t e d States E n v i r o n m e n t a l Protect ion A g e n c y ( U S E P A ) ( A T S D R , 1994a). There are 2 0 0 0 wood-treatment sites i n the U S that are i n need o f remediat ion (St inson et a l , 1991). O f these 2 0 0 0 sites, about 500 have P C P contaminat ion ( C i r e l l i , 1978). Short-term exposures to large amounts o f P C P or long-term exposure to l o w levels can h a r m the l iver , k i d n e y s , b l o o d , lungs, nervous system, i m m u n e system, and gastrointestinal tract. P C P is also a poss ible carc inogen, based o n a n i m a l studies. T h e U S E P A has set a d r i n k i n g water l i m i t o f 1 u.g/L for P C P ( A T S D R , 1994a). N P is f o u n d i n insecticides (notably mothbal ls) , dyes, resins, leather, and tanning agents and is also natural ly present i n foss i l fuels. It has been found i n at least 536 o f the N a t i o n a l 1 Prior i t ies L i s t sites identi f ied by the U S E P A . E x p o s u r e to h i g h levels o f N P c a n cause damage to red b l o o d cel ls . T h e U S E P A recommends that adults should not d r i n k water conta in ing m o r e than 1 m g / L N P over a seven-year per iod, and that c h i l d r e n s h o u l d not d r i n k water conta in ing m o r e than 0.5 m g / L for more than 10 days ( A T S D R , 1995). T L is present i n m a n y w i d e l y - u s e d products, i n c l u d i n g gasoline, n a i l p o l i s h , rubber cement, paints, paintbrush cleaners, stain removers, fabric dyes, inks , and adhesives, and has been found i n at least 869 o f the N a t i o n a l Pr ior i t ies L i s t sites ident i f ied by the U S E P A . It has been f o u n d i n waste sites and landf i l l s , h a v i n g been discarded as used solvent or as a component i n the consumer products mentioned above. Repeated exposure to h i g h levels o f T L can cause k i d n e y damage, bra in and speech damage, v i s i o n and hearing impairments , loss o f m u s c l e contro l , and m e m o r y loss. T h e U S E P A has set a d r i n k i n g water l i m i t for T L o f 1 m g / L ( A T S D R , 1994b). M E K is used as a solvent i n protective coatings, adhesives, p r i n t i n g i n k s , and paint removers. It is also used i n the product ion o f magnetic tapes and i n d e w a x i n g lubr icat ing o i l . I n 1992, 2.2 x 10 8 k g o f M E K were produced i n the U S ( U S E P A - O P P T , 1994). M E K has been f o u n d i n h i g h concentrations i n landf i l ls ( P a v e l k a et a l , 1993). Studies i n animals have s h o w n that repeated exposure to h i g h levels o f M E K i n air can cause l iver and k i d n e y damage, w h i l e h u m a n studies have indicated adverse central nervous system effects f r o m repeated or extended exposure to M E K ( U S E P A - O P P T , 1994). M E K has also been l i n k e d to fetal morta l i ty and b r a i n damage i n rats (Stol tenburg-Didinger et a l , 1990). C l a y is a natural, inexpensive material that is w i d e l y used to l i m i t the impact o f chemica ls o n the environment. Because o f the l o w hydraul ic conduct iv i ty (k) imparted to s o i l w h e n c lay is incorporated into the s o i l before compact ion , c lay is often a component o f l a n d f i l l l iners and other c lay barriers i n w h i c h l o w k is desirable ( E l s b u r y and Sraders, 1989). C lay ' s 2 inherent negative charge is an added advantage where heavy metal contaminat ion is a concern, as cat ionic metals w i l l sorb to the cat ion exchange sites o n the c lay ( M o h a m e d et a l , 1992). T h i s negative charge is also one reason that c lay is considered a p r i m e mater ia l for use i n nuclear waste containment systems (Tashiro et a l , 1998) and as a sorbent to remove radioact ive elements f r o m waste effluents f r o m nuclear reactors (Ade leye et a l , 1995). Other potential environmental applicat ions inc lude removal o f dyes f r o m waste effluent ( R a m a k r i s h n a and V i r a r a g h a v a n , 1997) and stabi l izat ion o f petroleum contaminated d r i l l i n g wastes ( T u n c a n et a l , 1997). A n i o n i c or n o n i o n i c pollutants are not retained w e l l by natural c lays , especia l ly i f the pollutants are * h y d r o p h o b i c ( X u et a l , 1997). M o s t o f the exchange sites o n c lays are o c c u p i e d b y N a + and/or C a 2 + . T h e hydrat ion shel l surrounding these ions causes the c lay surface to be a h y d r o p h i l i c environment. H y d r o p h o b i c organic contaminants ( H O C ' s ) w i l l not adsorb to these surfaces ( B o y d et a l , 1988). T h i s phenomenon is i l lustrated i n F i g u r e 1.1. It is possible to make clays more adsorptive to H O C ' s us ing cat ionic surfactants ( B o y d et a l , 1991). T h e N a + and C a 2 + o n the cat ion exchange sites are replaced by cat ionic surfactants. T h e cat ionic surfactants used are quaternary a m m o n i u m compounds consist ing o f a h y d r o p h o b i c and a h y d r o p h i l i c moiety . T h e h y d r o p h i l i c moiety is p o s i t i v e l y charged and adsorbs to the c l a y ' s cat ion exchange sites. T h e hydrophobic end o f the surfactant m o l e c u l e s changes the c lay surface f r o m a h y d r o p h i l i c environment to a h y d r o p h o b i c , o r g a n o p h i l i c environment ( G i e s e k i n g , 1939; Jordan, 1949; B o y d et a l , 1991). A n organic pseudophase is * Most research in this field has used the term "hydrophilic" to describe chemicals which are soluble in water at high concentrations, and "hydrophobic" for chemicals which are soluble in water only at very low concentrations. This practice is also followed in the present study, but it should be noted that using these terms in this way is not strictly correct. "Hydrophilic" is defined as "having a strong attraction to water" and "hydrophobic" as "having a lack of attraction to water" (Henold and Walmsley, 1984). On the other hand, solubility relates to the tendency of a substance to dissolve in water, i.e. to form a solution. A solution is "a homogeneous mixture of two or more created at the c lay surface. T h i s pseudophase acts as a part i t ion m e d i u m for H O C ' s , effectively so lvat ing the contaminants and i m m o b i l i z i n g them o n the c lay (Jaynes and B o y d , 1991). T h e m o d i f i c a t i o n o f the c lay by a cat ionic surfactant is s h o w n i n F i g u r e 1.2. T h e m o d i f i e d c lay is referred to as an organoclay. There are two general classes o f cat ionic surfactants used to produce organoclays , w h i c h are based o n the size and result ing hydrophobic i ty o f the surfactant ta i l ( B o y d et a l , 1991). These t w o classes are referred to as long-chain and short-chain surfactants. O n e example o f a l o n g - c h a i n surfactant is h e x a d e c y l t r i m e t h y l a m m o n i u m ( H D T M A ) , w h i c h has 16 carbon atoms i n its h y d r o p h o b i c t a i l , w h i l e te tramethylammonium ( T M A ) is an example o f a short-chain surfactant. T M A is s i m p l y a nitrogen atom w i t h four m e t h y l groups attached, and has no l o n g a l k y l group comparable to that o f H D T M A . Organoclays produced w i t h H D T M A w i l l have quite different characteristics to those produced w i t h T M A . C e r t a i n organic contaminants w i l l be adsorbed better b y organoclays produced w i t h H D T M A than those produced w i t h T M A , w h i l e for other organic contaminants the reverse w o u l d be true. M a n y appl icat ions have been suggested for organoclays: 1. Organoclays c o u l d be added to l iners i n hazardous or non-hazardous waste l a n d f i l l sites to enhance the l iners ' retention o f organic pollutants ( B o y d et a l , 1991; S m i t h and Jaffe, 1994). 2. Organoclays c o u l d be used i n the event o f terrestrial c h e m i c a l spi l l s to restrict the area contaminated and to safeguard groundwater ( B o y d et a l , 1991). 3. Organoclays c o u l d be inc luded i n hydrocarbon containment systems such as protective l iners for petroleum storage tanks ( B o l d t - L e p p i n et a l , 1996). T h e substances of molecular or ionic particle size, the concentration of which may be varied, usually within certain limits" (Peters, 1986). 4 leachabi l i ty o f certain organic compounds from contaminated soi ls c o u l d be reduced us ing organoclays ( B r i x i e and B o y d , 1994). 4. C e r t a i n organic pollutants c o u l d be r e m o v e d f r o m industr ia l wastewaters w i t h organoclays (Srinavasan and Fogler , 1990; A l t h e r , 1997). 5. C a t i o n i c surfactants c o u l d be injected i n aqueous so lut ion into a s u b s o i l , b o n d i n g to the natural ly occurr ing c lay and creating a h i g h l y adsorptive zone w h i c h c o u l d b l o c k contaminant migrat ion ( X u and B o y d , 1995). 6. Organoclays c o u l d be used to reduce v o l a t i l i z a t i o n o f organic contaminants d u r i n g s o l i d i f i c a t i o n o f organic wastes (Faschan et a l , 1992), or leachabi l i ty o f the organic contaminants f r o m s o l i d i f i e d so i l ( S e l l et a l , 1992). 7. O r g a n i c contaminants c o u l d be r e m o v e d from exhaust air us ing organoclays ( K u h n and W e i s s , 1988. M o s t research o n organoclays has been done i n organoclay-water suspensions. H o w e v e r , i n m a n y environmental applicat ions, organic chemicals encounter organoclays i n a compacted or non-compacted s o i l layer, not i n a suspension. I n these appl icat ions, the k o f the s o i l conta in ing organoclay becomes an important issue as w e l l as the capacity o f the organoclay to adsorb contaminants. In the case o f a l a n d f i l l l iner or other c lay barrier, extremely l o w k is desirable - the t y p i c a l m a x i m u m k a l l o w e d by regulatory agencies i n N o r t h A m e r i c a is 1 x 10-7 cm/s ( E l s b u r y and Sraders, 1989). H i g h e r k, however, is desirable i n some other appl icat ions, such as i n reactive barrier w a l l s (Hayes and M a r c u s , 1997; Waybrant et a l , 1995) or i n containment o f contaminant plumes ( X u et a l , 1997). It is therefore essential to have a better understanding o f what effect the use o f organoclay i n these applicat ions w i l l have o n k. 5 Figure 1.1: The hydration shell preventing adsorption of HOC's on clays Clay Surface Cationic Surfactant HOC's Ca 2 + and Na+ Ions Figure 1.2: Clay surface modified by a cationic surfactant 6 1.2 S C O P E AND O B J E C T I V E S O F T H E PRESENT STUDY T h i s study investigated the effects o f organoclay i n c l u s i o n o n k and adsorptivi ty o f compacted c lay barrier material . T h e objectives o f the study were to: I. Produce an organoclay for testing i n c lay barrier materia l . II. Test the adsorptivity o f this organoclay and untreated bentonite for P C P , N P , T L and M E K (the test chemicals) . III. Create s imulated c lay barrier material . I V . Determine the k o f the s imulated c lay barrier material . V . Determine i f the presence o f the test chemicals i n dilute concentrations affected the k o f the s imulated c lay barrier material . V I . Determine i f the adsorptivity o f the s imulated c lay barrier material for the test chemicals was enhanced by the i n c l u s i o n o f organoclay. T h e steps taken to achieve the stated objectives were: Object ive I A . O b t a i n a suitable base c lay for product ion o f organoclay. B . Replace most o f the C a 2 + and N a + ions o n the c l a y ' s cat ion exchange sites w i t h cat ionic surfactant molecules . T h e surfactant used was H D T M A . C . D r y and g r i n d the result ing organoclay. Object ive II A . P e r f o r m batch adsorption tests w i t h the organoclay and untreated c lay to determine the adsorptivi ty o f organoclay and untreated c lay for the test chemicals . 7 Object ive III A . C o m b i n e fine sand w i t h untreated bentonite and organoclay i n a ratio w h i c h ensures l o w k. B . Determine the o p t i m u m moisture content for these mixtures to g ive the m a x i m u m dry density w h e n compacted. C . C o m p a c t these mixtures to simulate the c o m p a c t i o n done i n construct ing c lay barriers. Object ive I V A . Construct a permeameter system capable o f measuring the k o f the samples w h i l e not c h e m i c a l l y interacting w i t h the test chemicals . B . Include the compacted s imulated l iner material i n a pressurized permeameter and measure the f l o w o f permeant through the compacted c lay barrier mater ia l over t ime. C . Calculate the k o f the sample f r o m the data o n the f l o w and elapsed t ime. Object ive V A . R e c o r d the f l o w o f permeants containing the test chemicals through compacted c lay barrier material . B . Calculate k data f r o m the f l o w informat ion. C . C o m p a r e k o f samples i n the presence or absence o f the test chemicals . Object ive V I A . A n a l y z e effluent f r o m the permeameter for the presence o f the test chemicals . 8 1.3 O R G A N I Z A T I O N O F THESIS F o l l o w i n g this introductory chapter, the second chapter presents a literature rev iew. T h e t h i r d chapter details the materials and methods used i n the present study. Chapter F o u r presents the experimental results and discusses these results i n the context o f other research that has been done o n organoclays. Chapter F i v e consists o f conclusions and suggestions for further research. M o r e detailed in format ion o n some aspects o f the research is presented i n the appendices. 1.4 CONTRIBUTIONS O F THIS R E S E A R C H M o s t w o r k o n organoclay to i m m o b i l i z e n o n - i o n i c contaminants to date has been done i n batch adsorpt ion tests. V e r y few systematic studies have e x a m i n e d the effects o f these contaminants o n k, or compared the adsorptive and k properties o f bentonite and organoclay i n c o l u m n leaching tests. T h i s study includes adsorptivity o f n o n - i o n i c contaminants o n organoclay and their effect o n h y d r a u l i c conduct iv i ty . A relat ively large number o f samples was studied i n comparat ive ly long-term c o l u m n leaching tests to s imulate the c lay barrier situation. T h e results o f this study w i l l provide a better understanding o f the effect o f H O C ' s o n k and adsorpt ion i n bentonite and organoclay, w h i c h w i l l provide Geo-environmenta l engineers a better foundat ion for selecting appropriate mixtures o f c lay barrier material and des igning proper barrier thickness. T h e results also provide a better understanding o f the interaction between organoclay, k, adsorpt iv i ty and H O C ' s that w i l l a l l o w engineers to predict the effectiveness o f sorbent zones to b l o c k contaminant m i g r a t i o n i n a g i v e n situation. T h i s research also provides i n f o r m a t i o n for engineers to predict the effectiveness o f sorbent zones to i m m o b i l i z e contaminant m i g r a t i o n . 9 C H A P T E R 2 L I T E R A T U R E R E V I E W 2.1 ADSORPTION STUDIES W I T H O R G A N O C L A Y S G a r w o o d et a l (1983) studied the adsorption o f the enzyme glucose oxidase o n m o n t m o r i l l o n i t e and o n organoclay prepared w i t h H D T M A . T h i s testing was done at different p H levels v a r y i n g between 3.0 and 8.0. T h e y found that the adsorption o f the e n z y m e by m o n t m o r i l l o n i t e was dependent o n p H , w h i l e adsorption b y the organoclay was not dependent o n p H . O v e r the p H range studied, the enzyme is present i n cat ionic , neutral and a n i o n i c forms. T h e authors c o n c l u d e d that i n the case o f m o n t m o r i l l o n i t e , the enzyme was b o u n d by electrostatic forces, w h i l e i n the case o f organoclay, the enzyme was b o u n d by h y d r o p h o b i c b o n d i n g . These results also i m p l y that the H D T M A b o u n d to the c lay was not i n any w a y affected b y the changes i n p H . I n a s i m i l a r study, B o y d and M o r t l a n d (1985) found that the adsorpt ion o f the enzyme urease o n organoclay prepared w i t h H D T M A was not affected by p H over the range o f 5.0 to 8.0. M o r t l a n d et a l (1986) prepared organoclays us ing smectite der ived f r o m bentonite. T h e c lay was prepared w i t h H D T M A and also w i t h three other cat ionic surfactants: h e x a d e c y l p y r i d i n i u m ( H D P Y ) , t r i m e t h y l p h e n y l a m m o n i u m ( T M P A ) , and t e t r a m e t h y l a m m o n i u m ( T M A ) . H D T M A and H D P Y are long-chain a l k y l a m m o n i u m cations, w h i l e T M P A and T M A are short-chain a l k y l a m m o n i u m cations. These researchers tested the organoclays' adsorptivity for phenol , 3-chlorophenol , 3,5-d i c h l o r o p h e n o l , and 3,4,5-tr ichlorophenol us ing batch adsorption methods. T h e more h y d r o p h o b i c compounds (i.e. the d i c h l o r o p h e n o l and tr ichlorophenol) were best adsorbed b y 10 clays treated w i t h the long-chain cations H D T M A and H D P Y , w h i l e the m o r e h y d r o p h i l i c c o m p o u n d s were best adsorbed b y clays treated w i t h the short-chain cations T M P A and T M A . T h e adsorptivi ty o f phenols and chlorophenols o n H D T M A was i n the order p h e n o l < 3-chlorophenol < 3 ,5-dichlorophenol < 3,4,5-tr ichlorophenol . T h e adsorptivi ty o f these phenols and chlorophenols increased w i t h increasing c h l o r i n a t i o n and increasing h y d r o p h o b i c i t y . T h i s c o n c l u s i o n led B o y d et a l (1988) to test organoclays ' adsorptivi ty for P C P . Bes ides H D T M A , H D P Y , T M P A , and T M A , these researchers investigated P C P adsorption o n c lay treated w i t h d i o c t o d e c y l d i m e t h y l a m m o n i u m ( D O D M A ) , 4 - m e r c a p t o p y r i d i n i u m ( 4 - M P ) , and a m m o n i u m ( N H 4 + ) . A s might be expected from the results o f M o r t l a n d et a l (1986), the c lays treated w i t h l o n g - c h a i n cations ( H D T M A , H D P Y and D O D M A ) were b y far the best adsorbents for P C P . A t p H 5.5, the m a x i m u m adsorption o f P C P o n bentonite exchanged w i t h H D T M A was almost 32,000 mg/kg. A t p H 10, the m a x i m u m adsorption was s l ight ly less (about 2 6 , 0 0 0 mg/kg). T h e adsorpt ion o f N P , T L , benzene, ethylbenzene,/^-xylene, and butylbenzene by c lays m o d i f i e d w i t h T M A and T M P A was studied by Jaynes and B o y d (1990). T h e highest adsorpt ion reported was s l ight ly less than 4 0 , 0 0 0 mg/kg for T L , and s l ight ly less than 12,000 mg/kg for N P . T M P A - b e n t o n i t e adsorbed both T L and N P m u c h better than T M A - b e n t o n i t e . T h e m o d i f i c a t i o n o f three different natural soils w i t h H D T M A greatly increased the adsorptivi ty o f the soi ls for T L , tetrachloroethylene, ethylbenzene, benzene, tr ichloroethylene, o-dichlorobenzene, and 1,2,4-trichlorobenzene (Lee et a l , 1989). H D T M A enhanced the adsorptivi ty o f various c lays for N P , propylbenzene, butylbenzene, t-butylbenzene, and b i p h e n y l (Jaynes and B o y d , 1991). 11 F a s c h a n et a l (1993 a) concluded that the adsorption o f nitrobenzene and 1,2-dichlorobenzene o n two c o m m e r c i a l l y available organoclays were not affected by h i g h concentrations o f C a ( O H ) 2 and h i g h p H (11.1-12.4), w h i l e the adsorption o f p h e n o l was decreased i n these condit ions. T h e y proposed that phenol d i d not adsorb as w e l l at a higher p H (compared to p H 7.0 i n d is t i l l ed , de ionized water) since it w o u l d be i o n i z e d at these p H levels and therefore rendered less hydrophobic . B r i x i e and B o y d (1994) tested P C P adsorption o n a c o m m e r c i a l l y - p r o d u c e d organoclay. A t p H 4.95, the highest adsorption recorded was 2 2 0 , 0 0 0 m g P C P / k g organoclay. A t p H 11.50 (and w i t h the cement-based s o l i d i f i c a t i o n agent S o r b o n d included) , the highest adsorpt ion recorded was about 110,000 mg/kg. Stapleton et a l (1994) investigated the so lubi l i ty o f P C P at different p H values and i o n i c strengths, as w e l l as the adsorption o f P C P by bentonite m o d i f i e d w i t h H D T M A at different p H values and i o n i c strengths. T h e y conc luded that between p H 4.0 and 8.5, P C P s o l u b i l i t y increased b y three orders o f magnitude because o f the change f r o m the protonated to the deprotonated f o r m (the p K a o f P C P is 4.75). T h e increase i n s o l u b i l i t y at higher p H values was a c c o m p a n i e d by a large decrease i n P C P adsorption - at p H 4 .0 , the highest adsorpt ion recorded was near 160,000 mg/kg, w h i l e at p H 8.5, the highest adsorption recorded was s l ight ly less than 67 ,000 mg/kg. T h e effects o f i o n i c strength were negl ig ib le , except at p H 8.5, where s l ight ly h igher adsorpt ion occurred at the higher i o n i c strength (0.1 M N a C l vs. 0.001 M N a C l ) . A n organoclay produced by treating bentonite w i t h the cat ionic surfactant d i m e t h y l d i s t e a r y l a m m o n i u m was tested for adsorption o f tannic ac id , p h e n o l and 2,4,5-t r i c h l o r o p h e n o l (Dentel et a l , 1995). A l l o f these compounds were adsorbed m u c h better by the organoclay than by untreated bentonite, w i t h uptake increasing i n the order p h e n o l < tannic a c i d < 2 ,4,5-tr ichlorophenol . T h e h y d r o p h o b i c i t y o f these compounds increases i n the same order. These authors also found p H effects w i t h the phenol ic compounds , w i t h decreasing adsorpt ion at higher p H levels , tending to c o n f i r m the f indings o f Stapleton et a l (1994). Faschan et a l (1993 b) considered the adsorptivity o f f ive different c o m m e r c i a l l y avai lable organoclays for nitrobenzene and 1,2-dichlorobenzene. T h e y compared their results to ex is t ing m o d e l s used to predict the adsorption o f n o n i o n i c organic c o m p o u n d s onto the organic fract ion o f natural soils and sediments. These researchers found that the models underestimated the adsorption o f nitrobenzene and 1,2-dichlorobenzene by at least an order o f magnitude, i n d i c a t i n g that the synthetic organic matter produced i n organoclay is a m u c h more efficient adsorbing m e d i u m than natural organic matter i n soi ls and sediments. S m i t h and Jaffe (1994) tested the adsorption o f benzene onto bentonite m o d i f i e d w i t h H D T M A . T h e highest adsorption these researchers recorded was about 12,000 mg/kg. Bottero et a l (1994) found that organoclays adsorbed more atrazine from r iver water conta in ing natural background organics than f r o m water containing approximate ly the same salt concentrations as found i n the r iver water. T h e adsorptivi ty o f untreated m o n t m o r i l l o n i t e and organoclay for lead ( P b 2 + ) and three chlorobenzenes was compared by L o and Li l jes trand (1996). T h e untreated m o n t m o r i l l o n i t e adsorbed 12 t imes more P b 2 + than d i d the organoclay. T h e organoclay adsorbed 600 t imes more 1,2,4-trichlorobenzene, 450 t imes more 1,2,4,5-tetrachlorobenzene and 4 2 0 t imes m o r e 1,2-dichlorobenzene than d i d the untreated m o n t m o r i l l o n i t e . T h e sorpt ion o f the chlorobenzenes increased w i t h increasing hydrophobic i ty . L o et a l (1996) d i d batch adsorption tests us ing an organoclay prepared w i t h t r i c a p r y l m e t h y l a m m o n i u m , a long-chain cat ionic surfactant. T h e permeants contained 10,000 13 m g / L o f the B T E X compounds (benzene, toluene, ethylbenzene, xylenes - c o m m o n l y found i n gasoline) as s ingle solutes. F o r T L , these researchers reported adsorptions o f up to 75 ,000 m g T L / k g organoclay. T h e e q u i l i b r i u m (final) concentration o f T L was reported to be more than 7,000 m g / L . H o w such h i g h solubi l i t ies were achieved for T L is not reported. T h e general ly accepted s o l u b i l i t y l i m i t for T L i n water is s l ight ly more than 500 m g / L (Jaynes and B o y d , 1991; Jaynes and V a n c e , 1996; L o et a l , 1997). A so lubi l i ty l i m i t o f 535 m g / L for T L is also g i v e n b y L o et a l (1996) i n a table. These researchers also found that the organoclay adsorbed the B T E X c o m p o u n d s 3-4 t imes better than d i d untreated bentonite. T h e adsorpt ion o f the B T E X compounds and four phenol ic c o m p o u n d s o n a c o m m e r c i a l l y avai lable organoclay was studied by L o et a l (1997). T h e sorpt ion o f a l l these c o m p o u n d s increased w i t h increasing hydrophobic i ty . T h e highest adsorption reported for T L was about 32 ,000 mg/kg. B a t c h adsorption tests were done at p H 5 and p H 9 - l itt le difference was observed i n adsorption at these different p H levels for T L or the other B T E X c o m p o u n d s , but a p H effect was found for the phenol ic compounds. There was less adsorption at p H 9 than at p H 5 for these chemicals , presumably due to the increased proport ion o f i o n i c species at the higher p H . T h e p H - i n d u c e d drop i n adsorption was m u c h less pronounced for p h e n o l than for the other c o m p o u n d s (2-chlorophenol , 2 ,4-dichlorophenol and 2,4,6-tr ichlorophenol) . C a d e n a and Jeffers (1987) investigated the adsorption o f T L , benzene, o-xylene, and c h l o r o f o r m o n bentonite m o d i f i e d w i t h T M A , a short-chain cat ionic surfactant. These authors reported adsorpt ion o f up 4 0 , 0 0 0 m g T L / k g organoclay. Jaynes and V a n c e (1996) investigated the adsorption o f a mixture o f the B T E X c o m p o u n d s o n a group o f organoclays prepared w i t h various long-chain cat ionic surfactants, i n c l u d i n g H D T M A . These researchers found that, i n the case o f o-xylene, adsorpt ion b y the organoclay was increased i n the B T E X mixture as compared to adsorption o f o-xylene w h e n 14 the other organic chemicals were not present. T h i s cosorpt ion effect was o n l y observed at higher loadings o f o-xylene (exceeding 1000 mg/kg). Sheng et a l (1996a) observed synergistic and antagonistic effects between bisolutes. F o r example , the adsorption o f tr ichloroethylene ( T C E ) by organoclays was higher i n a s o l u t i o n conta in ing nitrobenzene than i n a so lut ion w i t h T C E alone. I f the bisolute was ethyl ether, however , T C E adsorption was decreased as compared to so lut ion conta in ing T C E alone. A synergist ic effect o n adsorption onto organoclays and untreated bentonite was observed by Stockmeyer and K r u s e (1991). T h e y found that the presence o f organic c o m p o u n d s i n a batch adsorption test c o u l d enhance the adsorption o f heavy metals and that the presence o f heavy metals c o u l d enhance the adsorption o f organics. F o r example , an untreated bentonite adsorbed 7 1 % o f the z i n c ( Z n 2 + ) from a so lut ion i n a batch adsorption test. W h e n p h e n o l was added to the batch, 9 2 % o f the Z n 2 + was adsorbed. A n organoclay adsorbed 5 4 % o f the d ie thy l ketone i n another batch adsorption test; w h e n Z n 2 + was added to the batch, 9 5 % o f the d ie thy l ketone was adsorbed. These authors proposed that the synergist ic effect c o u l d be related to the f o r m a t i o n o f metal-organic complexes . T h e effect o f the presence o f an organic cosolvent (methanol) o n adsorpt ion o f N P arid d i u r o n by organoclays was examined by N z e n g u n g et a l (1996). I n general, the presence o f the cosolvent decreased adsorption o f N P and d i u r o n by the organoclays. These researchers also noted that N P adsorption was higher o n an organoclay m o d i f i e d w i t h T M P A , a short-chain cat ionic surfactant, than o n the organoclay m o d i f i e d w i t h H D T M A . T h o u g h the process o f H O C i m m o b i l i z a t i o n o n organoclays is not f u l l y understood, it is a lmost certain that so lvat ion into the organic pseudophase is o n l y one o f the mechanisms i n v o l v e d . Sheng et a l (1996b) d i d batch adsorption tests w i t h an H D T M A - m o d i f i e d c lay and m u c k s o i l to compare the mechanisms i n v o l v e d i n H O C sorption o n organoclays and natural 15 organic matter. T h e organic chemicals added to the aqueous permeants were benzene, nitrobenzene, chlorobenzene, tr ichloroethylene, and carbon tetrachloride. T h e results o f these tests supported m u l t i p l e mechanisms o f H O C sorption o n organoclays: 1. H O C part i t ioning into the organic pseudophase. 2. S o l v a t i o n o f the cat ionic a m m o n i u m centers o f the surfactant molecules . 3. S o l v a t i o n o f the a l k y l chains o f the surfactant molecules . 4. A d s o r p t i o n o f the H O C molecules to the c lay surface vacated due to reorientation o f the surfactant molecules caused b y 2 and 3 above. F o r natural s o i l organic matter, solute part i t ioning was the o n l y m e c h a n i s m these researchers be l ieved to be i n v o l v e d i n H O C adsorption. T h e y proposed that adsorpt ion o f organic contaminants by the surfactant-derived organic matter o f organoclays is m u c h higher than adsorpt ion by natural organic matter because o f these m u l t i p l e mechanisms and because o f the greater so lvency o f the organic components o f the surfactants. T h e adsorpt ion o f the ionizable pesticide d i c a m b a (3 ,6-dichloro-2-methoxy benzoic acid) by organoclays was studied b y Z h a o et al (1996). T h e y found that the organoclays (one o f w h i c h was prepared w i t h H D T M A ) w o u l d adsorb almost twice as m u c h d i c a m b a i n its molecular , n o n - i o n i z e d f o r m than i n its anionic , deprotonated f o r m . L e e et a l (1997) prepared an organoclay w i t h two cat ionic surfactants, a l o n g - c h a i n m o l e c u l e ( H D T M A ) and a short-chain molecule ( T M A ) . H D T M A occupied 4 5 % o f the clay's cat ion exchange capacity, and T M A 4 0 % . These researchers then d i d batch adsorption tests w i t h three phenol ic compounds us ing the H D T M A / T M A organoclay. T h e results indicated that adsorpt ion increased i n the order 3-cyanophenol < 4-nitrophenol < 2-chlorophenol , and that H D T M A had a greater role i n enhancing the clay's sorpt ion capacity for these phenols than d i d T M A . 16 S o m e o f the points f r o m this section w h i c h are most relevant to the present study are: 1. A d s o r p t i o n o f organic chemicals by organoclays produced w i t h l o n g - c h a i n molecules such as H D T M A generally increases i n direct p r o p o r t i o n to the h y d r o p h o b i c i t y o f the organic chemicals ; adsorption o n such organoclays is not p H -dependent unless changes i n p H affect the h y d r o p h o b i c i t y o f the organic c h e m i c a l , as i n the case o f P C P . 2. P C P is adsorbed m u c h better b y organoclay at l o w p H , since b e l o w p H 4.75 it is present most ly i n the n o n - i o n i z e d f o r m , w h i l e at higher p H values it is present m o s t l y i n the i o n i z e d f o r m . 3. A d s o r p t i o n o f i o n i z e d P C P by organoclay can also be very h i g h (e.g. 6 7 , 0 0 0 mg/kg -Stapleton et a l , 1994). 4. B o t h N P and T L are adsorbed w e l l b y organoclay. 2.2 H Y D R A U L I C C O N D U C T I V I T Y O F O R G A N O C L A Y S T h e h y d r a u l i c conduct iv i ty (k) o f c lay barrier material containing organoclay has been studied by S m i t h and his co-researchers ( S m i t h et a l , 1992; S m i t h and Jaffe, 1994). These researchers used b e n z y l t r i e t h y l a m m o n i u m ( B T E A ) as w e l l as H D T M A to m o d i f y a W y o m i n g Na-bentonite . U s i n g 0.005 N C a S 0 4 as a permeant, they found that k was greatly increased by the presence o f organoclay. A compacted s o i l mixture o f 9 2 % Ottawa sand and 8 % untreated bentonite h a d k = 1.09 x 10"8 cm/s. W h e n the untreated bentonite was replaced w i t h B T E A -bentonite, k increased to 3.83 x 10"4 cm/s. H o w e v e r , a mixture o f 8 8 % Ottawa sand, 8 % untreated bentonite and 4 % B T E A - b e n t o n i t e h a d a k o f 3.84 x 10"8 cm/s. A natural s o i l w i t h 1 9 % clay content was treated w i t h H D T M A b y W a l l a c e et a l (1995). U s i n g H P L C - g r a d e de-aired water as a permeant, the k o f this so i l was determined w i t h and 17 without the i m p o s i t i o n o f loading. L o a d i n g var ied f r o m 23.9 to 776 k P a . T h e untreated s o i l w i t h no l o a d appl ied had a k o f 5.43 x 10"3 crri/s. T h e treated s o i l h a d k = 1.14 x 10"3 cm/s, 7 9 % less than the untreated s o i l . W h e n loading was appl ied, both treated and untreated soi ls exhib i ted a drop i n k. H o w e v e r , treated soils lost less k w h e n loading was appl ied than d i d untreated soi ls , w i t h the effect that at higher loadings, the k o f untreated soi ls was m u c h l o w e r than that o f the treated soi ls . T h e k o f an untreated bentonite was compared to that o f an organoclay ( L o and L i l j e s t r a n d , 1996). N o effective stress was appl ied to the samples. W h e n permeated w i t h tap water, the untreated bentonite had k = 4.0 x 10" 1 0 cm/s, w h i l e the organoclay had k = 5.6 x 10"5 cm/s. W h e n a layer o f organoclay was used w i t h a layer o f untreated bentonite, k was 3.3 x 10"'° cm/s, actual ly somewhat l o w e r than that o f bentonite alone. T h e use o f this layer system was further tested w i t h a synthetic leachate containing 62.2 m g / L 1,2-dichlorobenzene, 106.6 m g / L P b 2 + , and 69.2 m g / L N a C l . T h e results indicated that k w h e n the synthetic leachate was used as a permeant was about three t imes higher than w h e n tap water was the permeant. There was o n l y a s m a l l difference i n & between samples containing organoclay (1.4 and 1.6 x 10"9 cm/s) and a sample w i t h 2 layers o f untreated bentonite (1.2 x 10"9 cm/s). A s i m i l a r study ( L o et a l , 1997) examined k for an organoclay under different effective stresses v a r y i n g between 35 and 140 k N / m 2 . These authors found that at effective stresses o f 70 k N / m 2 or greater, the organoclay's k was l o w e r than the c o m m o n regulatory leve l o f 1 x 10"7 cm/s. T h e effect o f different permeants at a constant effective stress o f 70 k N / m 2 was also investigated. T h e three permeants used were tap water, synthetic leachate (338 m g / L 2,4,6-t r i c h l o r o p h e n o l , p H buffered to 9), and actual leachate (832 m g / L total organic carbon, 124 m g / L suspended sol ids , p H 8.6). Synthetic leachate had the highest k (about 2.0 x 10"7 cm/s), f o l l o w e d b y actual leachate (about 5.0 x 10"8 cm/s) and tap water (about 8 x 10"9 cm/s). 18 B u d h u et a l (1997) compared the k o f untreated bentonite to that o f H D T M A - b e n t o n i t e under different consol idat ion stresses v a r y i n g f r o m 23.9 to 191.6 k P a . These authors observed that, w h e n water was the permeant, the k o f the organoclay was m u c h higher than that o f the untreated bentonite at a l l consol idat ion stresses. F o r example, at 95.8 k P a , untreated bentonite h a d k= 1.4 x 10"9 cm/s compared to 1.5 x 10"6 cm/s for organoclay. Pure organic f luids (acetone and benzene) were also used as permeants for the organoclay at a conso l idat ion stress o f 95.8 k P a . T h i s resulted i n A:-values more than 200 t imes smaller than the value for water at this c o n s o l i d a t i o n stress. Scanning electron microscope observations o f the bentonite before and after treatment w i t h H D T M A revealed a s tr ik ing change i n the c lay fabric, w h i c h m a y account for the differences i n k. T h e untreated bentonite had a dense plate- l ike fabric , compared to a more open granular fabric for the organoclay. C o m p a c t e d mixtures o f untreated bentonite, organoclay and O t t a w a sand were tested for k w h e n permeated w i t h d i s t i l l e d water or diesel fuel ( B o l d t - L e p p i n et a l , 1996). L a r g e differences i n k were observed for different mixtures , permeants and dry densities. A m i x t u r e o f 7 . 5 % untreated bentonite, 7 . 5 % organoclay, and 8 5 % Ottawa sand compacted to 1.75 g/cm 3 had a re lat ively h i g h k for water (7.0 x 10"6 cm/s), w h i c h dropped to 2.0 x 10"8 cm/s w h e n the m i x t u r e was permeated w i t h diesel fuel (the test ran for about 10 days). T h i s appeared to be the o p t i m u m m i x t u r e and dry density for c lay barriers to leakage f r o m underground storage tanks conta in ing diesel fuel , since a l o w k for diesel fuel c o m b i n e d w i t h a h i g h k for water is desirable (water retained w i t h i n the barrier c o u l d leak to corros ion o f the tank). S o m e o f the points f r o m this section w h i c h are most relevant to the present study are: 1. T h e i n c l u s i o n o f organoclay i n c lay barrier materials generally causes a large increase i n k. 19 2. T h i s increase i n k m a y be caused by a change i n the c lay fabric w h i c h occurs w h e n the c l a y is treated w i t h a cat ionic surfactant such as H D T M A . 2.3 O T H E R O R G A N O C L A Y STUDIES A b o x m o d e l o f an aquifer was used by B u r r i s and A n t w o r t h (1992) to test the concept o f arresting a contaminant p l u m e us ing a cat ionic surfactant. T h e 3 0 x 3 0 x 120 c m glass b o x was f i l l e d w i t h actual aquifer material , w h i c h had c lay and organic carbon contents o f 8 % and 0 . 0 2 % respectively. A f t e r establishing groundwater f l o w through the b o x at 2 m L / m i n , a sorbent zone was created w i t h i n the aquifer by injecting aqueous solutions o f H D T M A . T h e a d d i t i o n o f H D T M A d i d not change f l o w characteristics. A s imulated contaminant p l u m e (containing N P and tritiated water) was then injected into the m o d e l aquifer and a l l o w e d to f l o w through the sorbent zone. T h e results showed that N P was effectively i m m o b i l i z e d by the sorbent zone, w h i l e the tritiated water f l o w e d through, indicat ing that N P had been retained b y the H D T M A - t r e a t e d s o i l . O n c e an organic contaminant has been i m m o b i l i z e d i n a sorbent zone, it c o u l d be s l o w l y degraded by bacteria. H o w e v e r , cat ionic surfactants have been found to be t o x i c to bacteria ( N y e et a l , 1994). T h i s tox ic i ty is largely e l iminated w h e n the surfactant is b o u n d to c lay , and N P adsorbed b y so i l has been s h o w n to be avai lable to bacteria ( C r o c k e r et a l , 1995). A n o t h e r alternative to biodegradation is to remove organic contaminants f r o m the sorbent zone w i t h n o n i o n i c surfactants. T h i s concept was tested i n c o l u m n experiments by H a y w o r t h and B u r r i s (1997), w h o conc luded that a n o n i o n i c surfactant can effectively remove an H O C f r o m a sorbent zone. W a g n e r et a l (1994) used aquifer material largely c o m p o s e d o f sand i n c o l u m n experiments to test retardation o f 1,2-dichlorobenzene, 1,2,3-trichlorobenzene, 1,2,3,4-tetrachlorobenzene, and pentachlorobenzene. T h e breakthrough curves for untreated aquifer material were compared to breakthrough curves for aquifer material that had been treated w i t h the cat ionic surfactant d o d e c y l p y r i d i n i u m . C o m p l e t e breakthrough (i.e., effluent concentrat ion equal ing influent concentration) occurred o n a l l treated and untreated samples. H o w e v e r , breakthrough took s igni f icant ly longer for the treated material . F o r example , w h e n the permeant contained pentachlorobenzene, complete breakthrough occurred after 50 pore v o l u m e s had passed through the untreated material . W i t h the same permeant passing through treated mater ia l , 150 pore v o l u m e s were required before complete breakthrough was observed. B r i x i e and B o y d (1994) m i x e d organoclay into so i l contaminated w i t h P C P and compared the leachabi l i ty o f P C P f r o m the so i l w i t h and without organoclay. T h e organoclays w i t h l o n g - c h a i n cations ( i n c l u d i n g H D T M A ) dramatical ly reduced the leachabi l i ty o f P C P f r o m these soi ls . O r g a n o c l a y was added to mixtures o f Port land cement and s o i l contaminated b y p h e n o l , 2 ,4 ,6-tr ichlorophenol and P C P ( S e l l et a l , 1992). T h e objective o f c o m b i n i n g contaminated s o i l w i t h a s o l i d i f y i n g agent such as Port land cement is to stabil ize the hazardous s o i l . U n d e r U S E P A regulations, the result ing material must withstand a pressure o f 0.344 M P a w h e n a p p l i e d i n an unconf ined compressive strength test. T h e material must also not exceed m a x i m u m contaminant concentrations i n leachate as defined by the t o x i c i t y characteristic leaching procedure ( T C L P ) determination. A l l the mixtures tested had compress ive strength w e l l above that required b y regulations, so i n c l u s i o n o f organoclay d i d not create a p r o b l e m i n this regard. L e a c h i n g o f 2 ,4,6-tr ichlorophenol and P C P was greatly reduced, and p h e n o l leaching somewhat reduced, by i n c l u s i o n o f organoclay i n the m i x . These authors c o n c l u d e d that i n c l u d i n g organoclay i n these so i l s tabi l izat ion m i x e s c o u l d s igni f icant ly reduce leaching and not adversely affect compressive strength. 21 Faschan et a l (1992) investigated the i n c l u s i o n o f organoclay i n a s o l i d i f i c a t i o n m i x w i t h the purpose o f reducing v o l a t i l i z a t i o n o f organic compounds. T h e v o l a t i l i z a t i o n o f organic c o m p o u n d s due to the heat o f the m i x i n g and cur ing processes can be as h i g h as 9 0 % . T h e v o l a t i l i z a t i o n o f nitrobenzene and 1,2-dichlorobenzene f r o m Port land cement w i t h and without organoclay was measured (no so i l was i n v o l v e d i n this experiment). These researchers found that the incorporat ion o f organoclay reduced v o l a t i l i z a t i o n losses o f nitrobenzene and 1,2-dichlorobenzene b y 8 3 % and 9 0 % respectively. A f i l ter vessel f i l l e d w i t h organoclay was used to reduce o i l content i n water f r o m an o i l w e l l (A l ther , 1997). T h i s "produced water" is re-injected into the subsurface through a water in ject ion w e l l . N o r m a l l y , the w e l l w o u l d have to be serviced every 2-3 months to r e m o v e o i l p l u g g i n g up the w e l l . T h i s servic ing was rendered unnecessary b y organoclay treatment o f the p r o d u c e d water, and it was s h o w n that us ing organoclay i n this manner was a m o r e e c o n o m i c alternative than d o i n g the per iodic servic ing. M u c h less groundwater p o l l u t i o n w o u l d also result i f the treatment o p t i o n were f o l l o w e d . S o m e o f the points f r o m this section w h i c h are most relevant to the present study are: 1. There are applications for organoclay i n w h i c h h i g h k is desirable (e.g., i m m o b i l i z a t i o n o f an organic c h e m i c a l i n a sorbent zone). 2. There are applicat ions for organoclay i n w h i c h k is not a factor (e.g., the reduct ion o f v o l a t i l i z a t i o n o f organic chemicals i n s o l i d i f i e d mixtures) . 2.4 E F F E C T O F O R G A N I C C H E M I C A L S O N C L A Y H Y D R A U L I C C O N D U C T I V I T Y T h e k o f three c lay soils to the pure organic solvents benzene, xy lene , carbon tetrachloride, tr ichloroethylene, acetone, methanol and g l y c e r o l was determined by G r e e n et a l (1981). I n these tests, a l l organic solvents had lower k i n a g i v e n c lay s o i l than d i d water. These 22 researchers c o n c l u d e d that it is not a solvent's density or v iscos i ty that is o f p r i m e importance i n predic t ing its k through a c lay s o i l , but rather its hydrophobic i ty . A c a r et a l (1985) tested the effect o f acetone, benzene, nitrobenzene and phenol o n the k o f compacted kaol ini te . A s pure l i q u i d s , acetone and phenol caused a s l ight increase i n k (as c o m p a r e d to a control us ing 0.01 N C a S 0 4 solution), w h i l e benzene and nitrobenzene caused a large decrease i n k. A q u e o u s solutions o f the chemicals at 1000 m g / L were also tested and a l l exhib i ted s l ight decreases i n k. These authors also investigated the effect on k o f different permeameter types. U s i n g pure acetone as a permeant, they found that large increases i n k occurred i n a r i g i d - w a l l permeameter, w h i l e o n l y a sl ight increase i n k occurred i n a f l e x i b l e - w a l l permeameter. These tests were done at different effective stresses. T h e y conc luded that the increases i n k seen w i t h the r i g i d - w a l l permeameter c o u l d o n l y be expla ined by s i d e w a l l leakage result ing f r o m shrinkage o f the c lay. F o r e m a n and D a n i e l (1986) studied the difference i n k i n three different compacted c lays (kaol inite , i l l i t e , and smectite) w h e n permeated w i t h a 0.01 N C a S 0 4 so lut ion, pure methanol or pure heptane. These tests were done i n both r i g i d - w a l l and f l e x i b l e - w a l l permeameters. These authors found that w h i l e the type o f permeameter had litt le effect o n k w h e n the c lays were permeated w i t h 0.01 N C a S 0 4 so lut ion, m u c h higher k values were observed w i t h r i g i d - w a l l permeameters than w i t h f l e x i b l e - w a l l permeameters w h e n methanol or heptane were used as permeants. T h e y conc luded that the difference i n k observed between the different types o f permeameters resulted f r o m the appearance o f cracks and macropores i n the c lay , w h i c h i n turn resulted f r o m s o i l shrinkage caused by the organic f luids . T h e effect o n the k o f consol idated m o n t m o r i l l o n i t e and kaol in i te w h e n permeated w i t h pure acetic a c i d , ani l ine , methanol and xylene was examined b y U p p o t and Stephenson (1989). 23 . These researchers found that increases in k were on the order of two to three times the h of the control (a 1000 mg/L solution of magnesium sulphate heptahydrate or Epsom salt). A consolidometer was used to measure k of kaolinite and montmorillonite when permeated by water, pure acetone or pure methanol (Budhu et al, 1991). These authors found that the k o f montmorillonite was 17 times greater when permeated with acetone (as compared to water) and 9.6 times greater than water when permeated with methanol. The k of kaolinite was 3.4 times greater when permeated with acetone, compared to water, and 1.4 times greater than water when permeated with methanol. Using their own results and data from the work of other researchers, these authors concluded that the dielectric constant of the organic fluid was the only reliable predictor of the effect of organic fluids on clay permeability. They also tested the effect on k of mixtures of acetone-water and methanol-water. N o effect on k was observed, compared to water as a control, until approximately 70% of the fluid (by volume) was organic. A similar result was obtained by Fernandez and Quigley (1988), who found that aqueous solutions of ethanol and dioxane reduced k unless the concentration of the organics exceeded 70% (by volume) in the solution. Storey and Peirce (1989) concluded that k of compacted clay soil was not significantly increased by methanol in an aqueous solution until the concentration of methanol exceeded 60% by volume. Daniel et al (1988) tested the effect of various permeants with dilute concentrations of organic chemicals on the k of compacted clay soils. The permeants included leachate from an industrial solid-waste landfill, liquids from two industrial-waste impoundments, two simulated leachates containing organic chemicals, and a mixture of one of the impoundment liquids with chlorinated hydrocarbons. They found that k was not affected by the permeants. Bowders and Daniel (1989) did k tests on compacted specimens of kaolinite and illite-chlorite. They used aqueous solutions containing methanol, acetic acid, heptane, and 24 tr ichloroethylene as permeants. These authors conc luded that the dilute organic chemica ls had l itt le effect o n k unless the concentration o f the organics exceeded 8 0 % by v o l u m e . A leachate obtained f r o m a hazardous waste site was used i n a study last ing m o r e than two years to determine the l o n g term effect o f dilute concentrations o f organic chemicals o n c lay l iner permeabi l i ty (Sai and A n d e r s o n , 1991). t h e leachate contained chlor inated and aromatic hydrocarbons, p h e n o l and phthalates. T h e compacted c lay l iner mater ia l s h o w e d no increase i n permeabi l i ty dur ing the 2-year p e r i o d (more than four pore v o l u m e s o f leachate passed through the c lay l iner material over this t ime). S o m e o f the points f r o m this section w h i c h are most relevant to the present study are: 1. I n a r i g i d - w a l l permeameter, permeation o f compacted c lay or c lay s o i l w i t h pure organic f luids usual ly causes a large increase i n k - this increase is p r o b a b l y caused b y s o i l shrinkage, w h i c h i n turn causes cracks and macropores to develop i n the sample. 2. I n a f l e x i b l e - w a l l permeameter, permeation o f compacted c lay or c lay s o i l w i t h pure organic f luids generally has a m i n i m a l effect o n k, s ince effective stress can be mainta ined o n the sample and m i n i m i z e the occurrence o f cracks and macropores. 3. Permeat ion o f compacted c lay or c lay s o i l w i t h aqueous solutions o f organic chemicals generally does not affect k unless the concentration o f the organic c h e m i c a l i n the so lut ion exceeds 60 or 7 0 % . 2.5 RELATIONSHIP O F PRIOR R E S E A R C H T O T H E PRESENT STUDY M u c h research has been done o n adsorption o f organic chemicals b y organoclays i n batch adsorpt ion tests and o n the effect o f organic chemicals o n k o f compacted c lay or c lay soi ls (i.e., not i n c l u d i n g organoclay). S o m e studies have also addressed the issue o f the effect o f 25 organoclay on k. Very few studies have investigated the effect of organoclay on k of clay barrier materials by comparison to the same bentonite from which the organoclay was produced. The question of whether organoclay is an appropriate ingredient for clay barriers still has no definitive answer. The present systematic study attempts to understand the interaction between k of clay barrier materials which incorporate organoclay and aqueous dilute solutions of organic chemicals, such as might be found in real-life environmental situations. The k of clay barrier material which does not contain organoclay is relatively unaffected by the presence of dilute concentrations of organic chemicals in the permeant. If the k of clay barrier material containing organoclay is affected by the presence of these chemicals in the permeant, this should be taken into account when organoclay is used in any environmental application in which A; is a concern or a factor. The present study considers this interaction. Another important concern that has not been addressed by other research is whether the high adsorptivity of organoclay for HOC's in batch adsorption studies can be extrapolated to some environmental applications such as use in clay barriers. In a batch adsorption test, organoclay encounters HOC's in an agitated aqueous solution, while in a clay barrier, leachate containing HOC' s moves very slowly through a compacted clay or clay soil. The present study tested the permeant which had passed through the clay barrier material for the presence of HOC' s . 26 1-1 CHAPTER 3 MATERIALS AND METHODS 3.1 SOIL M A T E R I A L S 3.1.1 Origins T h e c lay used for this study was s o d i u m bentonite obtained f r o m C a n a d i a n C l a y Products i n W i l c o x , Saskatchewan. Organoclay was produced us ing the same bentonite. T h e c o m m e r c i a l sand used was W e d r o n 7080. 3.1.2 Physical properties 3.1.2.1 Grain size distribution G r a i n size d is tr ibut ion o f the sand, the untreated bentonite, and the organoclay was determined u s i n g dry s iev ing, wet s iev ing , and the hydrometer method. T h e s i e v i n g procedures were those set out b y L a m b e (1951). T h e hydrometer procedure was an adaptation o f the procedure described b y L a m b e (1951) and Bardet (1997). See A p p e n d i x A for detai led descriptions o f the methods used for hydrometer analysis. 3.1.2.2 Specific gravity Speci f ic gravity determinations were carried out us ing a method adapted f r o m the vo lume-disp lacement method expla ined i n L a m b e (1951). Deta i l s o f the m e t h o d o l o g y can be f o u n d i n A p p e n d i x B . 28 3.1.2.3 Specific surface Speci f ic surface was determined us ing an ethylene g l y c o l m o n o e t h y l ether ( E G M E ) method adapted f r o m El tantawy and A r n o l d (1973). See A p p e n d i x C for details o n the m e t h o d used. 3.1.2.4 Atterberg limits Test ing for Atterberg l i m i t s was done according to the procedure i n L a m b e (1951). L i q u i d l i m i t s were determined for untreated bentonite, organoclay, control s o i l # 2 and experimental s o i l # 4 (see 3.1.6 for a descript ion o f the preparation o f the contro l and experimental soi ls and 3.1.5 for a descript ion o f the organoclay preparation). P las t i c l i m i t was o n l y determined for untreated bentonite, as the other studied s o i l materials w o u l d not f o r m a thread as required b y the plastic l i m i t procedure. 3.1.2.5 Maximum dry density and optimum water content Before compact ing the soils to be used i n the hydraul ic conduct iv i ty (k) tests, it was necessary to determine the moisture content at w h i c h the soils reached m a x i m u m dry density, w h i c h is referred to as the o p t i m u m moisture content. T h i s was done us ing the c o m p a c t i o n test o u t l i n e d i n A S T M D 6 8 9 - 9 1 ( A m e r i c a n Society for Test ing and M a t e r i a l s , 1992). D e t a i l e d results and discussions for these tests are found i n A p p e n d i x D . 3.1.2.6 Organic carbon content T h e organic matter content o f the untreated bentonite was determined b y ashing the bentonite i n a muff le furnace for 2 h at 550° C . Organic carbon content was then estimated by assuming an organic matter:organic carbon ratio o f 1.7:1.0 (Brady , 1990). D e t a i l e d results and d iscuss ion for these tests are found i n A p p e n d i x E . 29 3.1.3 Physicochemical properties 3.1.3.1. pH T h e p H o f the three materials used (sand, untreated bentonite and organoclay) was measured i n d i s t i l l e d water and i n 0.01 M C a C l 2 w i t h an adaptation o f the m e t h o d used b y M c L e a n (1982). See A p p e n d i x F for details o n the procedure. 3.1.3.2 Cation exchange capacity C a t i o n exchange capacity ( C E C ) o f the bentonite and the sand was determined u s i n g a m o d i f i e d v e r s i o n o f the s o d i u m acetate replacement method described by Rhoades (1982). Deta i l s o f the procedure are g iven i n A p p e n d i x G . 3.1.4 Mineralogical properties X - R a y D i f f r a c t i o n ( X R D ) was performed o n bentonite and o n organoclay to determine the basal spacing o f the c lays. Oriented samples o f the clays o n glass slides were submitted to X R D analysis o n a P h i l l i p s X - R a y diffractometer, us ing C u K c t , N i f i l tered radiat ion. 3.1.5 Preparation of organoclay 3.1.5.1 Organoclay production O r g a n o c l a y was produced i n the f o l l o w i n g w a y : 100.0 g o f untreated bentonite was suspended i n 1 L o f d is t i l l ed water, and 15.05 g o f the b r o m i d e salt o f H D T M A ( H D T M A - B r ) was d i s s o l v e d i n 500 m L o f w a r m dis t i l l ed water. T h i s proport ion o f H D T M A - B r and bentonite was calculated to cause 7 0 % o f the clay's cat ion exchange sites to be o c c u p i e d by H D T M A . T h e clay's cat ion exchange capacity ( C E C ) was 59 cmol/kg . T h e methods used to determine C E C and the results are presented i n A p p e n d i x G . 30 T h e H D T M A - B r so lut ion was gradual ly added to the bentonite suspension. T h e result ing mixture was v i g o r o u s l y stirred. Af ter leav ing the mixture to equil ibrate for 48 h , it was d r i e d for 24 h at 105° C , and the result ing organoclay ground w i t h a mortar and pestle. 3.1.5.2 Confirmation of surfactant adsorption T o t a l carbon analyses were performed to determine i f the H D T M A had been adsorbed o n the cat ion exchange sites. Detai ls o f the methods used for the total carbon analyses are g i v e n i n A p p e n d i x E . 3.1.6 Preparation of control and experimental soils T h e first control s o i l ( so i l # 1) contained 88.0 % fine sand and 12.0 % untreated bentonite, w h i l e the first experimental s o i l (soi l # 3) consisted o f 88.0 % sand, 8.0 % bentonite, and 4.0 % organoclay. D u e to a c o m b i n a t i o n o f t ime constraints and a very l o w f l o w rate o f permeants through these soi ls dur ing the first k tests, it was decided to change the s o i l m i x to incorporate less bentonite and organoclay and thereby increase k. T h e second control s o i l ( so i l # 2) consisted o f 9 2 . 5 % sand and 7 . 5 % bentonite. T h e second experimental s o i l ( so i l # 4) consisted o f 92.5% sand, 5.0 % bentonite, and 2 . 5 % organoclay. S ince c o m p a c t i o n was to be carried out at the o p t i m u m moisture content plus 1%, a l l soi ls were brought to the desired moisture content after dry m i x i n g . S o i l # 1 (the first control soi l) was made up by m i x i n g 1760.0 g o f sand w i t h 2 4 0 . 0 g o f untreated bentonite i n a plastic basin. T h e sand and bentonite were then thoroughly m i x e d by hand. A f t e r this , 0.01 M C a S 0 4 was added i n 50 m L aliquots u n t i l the desired moisture content had been achieved. 31 S o i l # 2 (the second control soi l) was made up by m i x i n g 1850.0 g o f sand w i t h 150.0 g o f bentonite i n a plast ic basin. T h e procedure was the same as for s o i l H 1 except that 0.01 M C a C l 2 s o l u t i o n was used instead o f 0.01 M C a S 0 4 so lut ion to wet the s o i l . S o i l # 3 (the first experimental soi l) was made up by m i x i n g 1760.0 g o f sand w i t h 160.0 g o f untreated bentonite and 80.0 g o f organoclay i n a plast ic basin. Otherwise , the procedure was the same as for so i l # 1. S o i l # 4 (the second experimental soi l) was prepared by m i x i n g 1850.0 g o f sand, 100.0 g o f untreated bentonite, and 50.0 g o f organoclay i n a plastic basin. Otherwise , the procedure was the same as for so i l # 2. T h e soi ls were left to equil ibrate for 48 h i n a h u m i d r o o m , then subsamples o f the soi ls were taken for moisture content determination. In most cases, moisture content was s l ight ly less than the desired moisture content, so more 0.01 M C a C l 2 or 0.01 M C a S 0 4 was added (about 10 m L ) . O n t w o occasions, the water content was higher than the desired water content, so the wet s o i l was exposed to the air u n t i l the extra water had evaporated f r o m the s o i l . T h e soi ls were stored i n plast ic containers i n the h u m i d r o o m . 3.2 C H E M I C A L S 3.2.1 Hexadecyltrimethylammonium H e x a d e c y l t r i m e t h y l a m m o n i u m ( H D T M A ) was the cat ionic surfactant used to m o d i f y the untreated bentonite to produce organoclay. T h e bromide salt o f H D T M A was obtained f r o m A l d r i c h C h e m i c a l C o m p a n y . 32 3.2.2 Test chemicals T h e test chemicals are those that were used i n dilute concentrations i n the adsorpt ion tests and i n the permeant for the k tests. P C P was obtained f r o m A l d r i c h , M E K and T L were obtained f r o m Fisher , and N P f r o m Supelco. Some o f the p h y s i c a l properties o f these chemicals are s h o w n i n T a b l e 3.1. Table 3.1: Physical properties of test chemicals Chemical Water Molecular Density (g/cm3) Vapour, log C A S R N solubility weight Pressure (mg/L) (g/mol) (mm Hg) P C P 14 266.34 1.98 0 5.00 87-86-5 N P 3 2 * 128.17 1.16 0.082 3.36* 91-20-3 T L 5 3 5 * * 92.15 0.87 22 2.51** 108-88-3 M E K 3.5 x 10 5 72.12 0.81 78 0.26 78-93-3 * V e r s c h u e r e n (1983) ** L i t t l e (1970) 3.3 ADSORPTION C H A R A C T E R I S T I C S T h e batch adsorption method was used to assess the adsorption o f the test chemica ls by organoclay and bentonite. T h i s p r o v i d e d a p r e l i m i n a r y idea o f h o w successful organoclay and bentonite w o u l d be i n adsorbing the test chemicals i n the k tests. 3.3.1 Pentachlorophenol P C P is an ionizable organic c o m p o u n d (Stapleton et a l , 1994). It m a y be present i n aqueous so lut ion as either the i o n i z e d or n o n - i o n i z e d species. W h i c h species w i l l predominate depends o n the p H o f the so lut ion i n relat ion to the p K a o f P C P . A t p H « p K a , most P C P i n s o l u t i o n w i l l be n o n - i o n i z e d , w h i l e at p H » p K a , most P C P i n so lut ion w i l l be i n the i o n i c f o r m . T h e p K a o f P C P is 4.75 (Stapleton et a l , 1994). 33 T h e i o n i z e d species o f P C P w o u l d be expected to have different adsorpt ion characteristics than the n o n - i o n i z e d species. W h e n P C P is present as the i o n i z e d species, it is m o r e h y d r o p h i l i c than the n o n - i o n i z e d species, so it should not adsorb as w e l l to organoclay as the m o l e c u l a r species. Because o f the different adsorption characteristics anticipated for the i o n i z e d and n o n - i o n i z e d forms o f P C P , batch adsorption tests were done i n both ac id ic and basic solutions. 3.3.1.1 Acidic solution T o measure the adsorptivity o f organoclay and bentonite for P C P , 0.30 g o f bentonite or 0.010 g o f organoclay were p laced i n 2 5 0 - m L glass bottles. It was necessary to use a m u c h smal ler quantity o f organoclay than bentonite since larger amounts adsorbed v i r t u a l l y a l l the P C P i n so lut ion. T h e bottles were capped w i t h l ids l i n e d w i t h polytetrafluoroethylene ( P T F E , sometimes marketed as Teflon®). T h e use o f P T F E was necessary to ensure that no interact ion occurred between the so lut ion and the cap l i n i n g . S o l i d P C P was d isso lved at a concentrat ion o f 10,000 m g / L i n methanol . A 2.00 L glass v o l u m e t r i c flask was f i l l e d w i t h i n 10 m L o f the 2.00 L m a r k w i t h 0.1 M K C 1 , after w h i c h 2.00 m L o f the methanol so lut ion was added to the flask. A s some o f the P C P d i d not d issolve , a f e w drops o f 1.0 M N a O H were added to facilitate so lvat ion , after w h i c h the flask was brought up to 2.00 L w i t h 0.1 M K C 1 . T h e so lut ion o f 10 m g / L P C P i n 0.1 M K C 1 was brought to p H 4.0 us ing 1.0 M H 2 S 0 4 . A l l p H measurements were done w i t h a B e c k m a n (p44 p H meter and an O a k t o n epoxy body p H electrode. T h e 10 m g / L P C P solut ion was c o m b i n e d w i t h 0.1 M K C 1 ( w h i c h h a d also been adjusted to p H 4.0) i n var ious ratios i n the glass bottles to g ive 2 0 0 m L o f 0, 2, 4, 6, 8, and 10 m g / L P C P solutions. O n e 200 m L al iquot o f 10 m g / L P C P was p laced i n a 250 m L glass bottle 34 without any organoclay or bentonite. T h i s sample underwent the same procedures as the samples w h i c h contained organoclay or bentonite i n order to account for losses o f P C P , part icular ly to v o l a t i l i z a t i o n . T h e bottles were then m a n u a l l y shaken, a l l o w e d to settle for 1 h , and p H was adjusted to 4.0 once again us ing 1.0 M H 2 S 0 4 . T h e bottles were turned at 13 r p m o n a rotary tumbler for 24 h . A f t e r turning , 10.0 m L subsamples were poured f r o m the bottles into 13 m L glass centrifuge tubes capped w i t h P T F E -l i n e d l ids . A f t e r centri fuging for 15 m i n at 3500 r p m i n a B e c k m a n G S - 6 centrifuge w i t h a B e c k m a n G H 3.8 head, 5.0 m L o f the supernatant was extracted w i t h a glass dropper and transferred to 5.0 m L glass sample bottles w i t h P T F E - l i n e d l ids . Samples were kept i n the dark at 4° C u n t i l extraction and gas chromatograph ( G C ) analysis c o u l d be performed. T h e p H o f the so lut ion r e m a i n i n g i n the 250 m L bottles was measured to determine i f p H h a d been further affected by interaction w i t h the c lay and/or P C P dur ing the batch adsorpt ion procedure. F o r extraction o f P C P into hexane pr ior to G C analysis , the 5 m L samples were transferred to 15 m L glass bottles w i t h P T F E - l i n e d l ids . 100 u L o f 5 M K 2 C 0 3 and 30 u L o f acetic anhydride ( w h i c h had been washed twice w i t h hexane) were added to the samples. T h e samples were then shaken for 1 m i n and left to equil ibrate for 15 m i n . T h e reason for adding the K 2 C 0 3 and acetic anhydride was to acetylate a l l P C P i n the sample, w h i c h facilitates G C analysis . F o l l o w i n g the acetylation procedure, 3.0 m L o f hexane was added to the samples, w h i c h were then shaken again for 1 m i n . T h e hexane was d r a w n o f f f r o m the top o f the aqueous sample, and then underwent G C analysis. See A p p e n d i x H for detai led G C condit ions . 35 3.3.1.2 Basic solution T h e basic batch adsorption test was done at p H 10.0 w i t h 0.30 g o f bentonite and 0.050 g o f organoclay. Adjustment o f p H to 10.0 was done w i t h 1.0 M N a O H . In a l l other respects, this test was ident ical to the ac idic batch adsorption test. 3.3.2 Naphthalene T o measure the adsorptivity o f organoclay and bentonite for N P , 0.30 g o f organoclay or bentonite were p laced i n 2 5 0 - m L glass bottles w i t h P T F E - l i n e d l ids . S o l i d N P was d i s s o l v e d at a concentrat ion o f 1000 m g / L i n methanol . A 2.00 L glass v o l u m e t r i c f lask was f i l l e d w i t h i n 4 0 m L o f the 2.00 L m a r k w i t h 0.01 M C a C l 2 , after w h i c h 20.0 m L o f the methanol so lut ion was added to the flask. T h e flask was then brought up to 2.00 L w i t h 0.01 M C a C l 2 . T h e procedures used for preparation o f different concentrations o f N P i n 0.01 M C a C l 2 , m i x i n g , centrifugation, s a m p l i n g o f the supernatant, and storage were the same as descr ibed above for P C P . F o r extraction o f N P into methylene chlor ide pr ior to G C analysis , the 5 m L samples were p laced i n 15 m L glass bottles w i t h P T F E - l i n e d l ids . 1 m L o f methylene chlor ide was added to the samples, w h i c h were then shaken v i g o r o u s l y for 1 minute. T h e methylene 'chlor ide was d r a w n o f f f r o m the bot tom o f the aqueous sample (methylene chlor ide is denser than water), and underwent G C analysis. See A p p e n d i x H for detai led G C condit ions . 3.3.3 Toluene A 100 m g / L so lut ion o f T L was produced by adding 230 u L (200 mg) o f T L to 2.00 L o f 0.01 M C a C l 2 i n a 2.00 L glass vo lumetr ic flask. T h e flask was shaken v i g o r o u s l y , covered, and left to equil ibrate overnight. 36 T h e batch adsorption test was done i n 13 m L glass tubes w i t h P T F E - l i n e d l ids . A f t e r adding 0.40 g o f bentonite or organoclay to each tube, 10.0 m L o f 0, 2 0 , 4 0 , 6 0 , 80 or 100 m g / L T L s o l u t i o n was added. These solutions were obtained by d i l u t i n g the 100 m g / L T L s o l u t i o n ment ioned above w i t h appropriate amounts o f 0.01 M C a C l 2 . T h e tubes were turned at 13 r p m o n a rotary tumbler for 24 h , then centrifuged at 3500 r p m i n a B e c k m a n G S - 6 centrifuge w i t h a B e c k m a n G H 3.8 head for 15 m i n . U s i n g a glass dropper, 5.0 m L samples f r o m the supernatant were extracted and measured i n a 5.0 m L glass graduated cy l inder . These 5.0 m L samples were then transferred to 15.0 m L glass bottles w i t h P F T E - l i n e d l i d s , T L was extracted into methylene chlor ide b y adding 2.0 m L methylene ch lor ide to each 15 m L bottle and shaking for 1 m i n . A n a l y s i s o f the methylene chlor ide extract was done o n a G C (see A p p e n d i x H for a descript ion o f G C condit ions) . 3.3.4 Methyl Ethyl Ketone A 10 m g / L so lut ion o f M E K was produced by adding 25 u L (20 m g ) o f M E K to 2.00 L o f 0.01 M C a C l 2 i n a 2.00 L glass vo lumetr ic flask. A q u e o u s solutions o f 0.01 M C a C l 2 w i t h 0, 2, 4, 6, 8 and 10 m g / L M E K were prepared us ing this so lut ion and were c o m b i n e d w i t h 0.10 g o f untreated bentonite or organoclay i n 13 m L glass centrifuge tubes capped w i t h P T F E - l i n e d l ids . T h e v o l u m e o f l i q u i d i n each tube was 10.0 m L . T h e tubes were turned at 13 r p m o n a rotary t u m b l e r for 24 h . Af ter centrifugation at 3500 r p m i n a B e c k m a n G S - 6 centrifuge w i t h a B e c k m a n G H 3.8 head for 15 m i n , 1.0 m L subsamples o f the supernatant were extracted w i t h a glass dropper and p laced direct ly into 2.0 m L glass v ia ls . These aqueous samples underwent G C analysis for M E K . See A p p e n d i x H for detailed G C condit ions. 37 3.4 H Y D R A U L I C C O N D U C T I V I T Y TESTING 3.4.1 Apparatus 3.4.1.1 Compaction apparatus T h e same cel ls were used i n both the c o m p a c t i o n procedure and the c o l u m n leaching tests. T h e cel ls consisted o f two parts: an outer a l u m i n u m jacket to preserve the structural integrity o f the compaction/leaching ce l l and an inner P T F E l iner to prevent interact ion o f the c e l l w i t h the test chemicals . T h e inner P T F E l iner fit snugly w i t h i n the outer a l u m i n u m jacket. T h e outer a l u m i n u m jacket was a c ircular piece o f a l u m i n u m tubing 5.08 c m l o n g , w i t h an outside diameter o f 7.62 c m and an inner diameter o f 6.03 c m . T h e inner P T F E l i n e r was also 5.08 c m l o n g , and had an outer diameter o f 6.03 c m and an inner diameter o f 5.08 c m . A schematic o f the assembled compact ion apparatus is s h o w n i n F i g u r e 3.1, and a schematic o f the c e l l used i n both the c o m p a c t i o n apparatus and the permeameter apparatus is s h o w n i n F i g u r e 3.2. Photographs o f the assembled c o m p a c t i o n apparatus, the c e l l conta in ing compacted s o i l , and the top and bot tom plates o f the c o m p a c t i o n apparatus can be seen i n F igures 3.3, 3.4 and 3.5 respectively. N o t e that the top plate o f the c o m p a c t i o n apparatus is o n the r ight i n the photograph (Figure 3.5). T h e top and bottom plates o f the c o m p a c t i o n apparatus were c o m p o s e d o f steel. 3.4.1.2 Hydraulic conductivity apparatus A schematic and a photograph o f the o f the permeameter apparatus are presented i n F igures 3.6 and 3.7, respectively. A l l elements o f the permeameter w h i c h came into contact w i t h permeants were c o m p o s e d o f glass or P T F E , or were coated w i t h P T F E . T h e o n l y except ion to this was the porous stones, w h i c h were composed o f c o r u n d u m , an inert m i n e r a l substance. T w o reservoirs w i t h a capacity o f 6.0 L each were used. C o l l e c t i o n was done i n 250 m L glass bottles. 38 T o p Plate (Steel) Compact ion/Permeameter C e l l ( A l u m i n u m and P T F E ) B o t t o m Plate (Steel) Figure 3.1: Compaction apparatus (assembled, side view) A l u m i n u m Jacket Inside Diameter = 5.08 c m • P T F E l iner Figure 3.2: Top view of compaction/permeameter cell 39 40 Figure 3.5: Top and bottom compaction apparatus plates (top plate on right) Pressur ized air inlet G a u g e \ C o l l e c t i o n bottles / P T F E tubing Figure 3.6: Schematic of permeameter system Permeameter c e l l conta in ing control or experimental s o i l 41 Figure 3.7: Permeameter apparatus in laboratory 3.4.2 Compaction procedure U s i n g the results f r o m the determination o f m a x i m u m dry density and o p t i m u m water content described above i n 3.1.2.5, the soils were compacted at 1% wet o f o p t i m u m moisture content. Three lifts o f s o i l were p laced i n a compaction/permeameter c e l l . E a c h lift was 77 g wet. A f t e r adding the l i ft to the c o m p a c t i o n ce l l , it was m a n u a l l y compressed w i t h a p lunger as m u c h as possible , then 25 b l o w s o f a 450 g compact ion hammer were a p p l i e d over a drop o f 40 c m . T h e dry densities o f the compacted cells varied between 1.76 and 1.81 g/cm 3 . T o prevent s i d e w a l l leakage, a t h i n layer o f bentonite (between 0.8 and 1.0 g dry weight at between 1 6 0 % and 1 8 0 % water content) was appl ied to the w a l l s o f the c e l l before b e g i n n i n g c o m p a c t i o n . The bentonite was moistened enough to become plastic and adhere to the c e l l 42 w a l l s . It was necessary to reapply bentonite after the first and second lifts since m u c h o f it was scraped o f f the w a l l s d u r i n g the c o m p a c t i o n process. A f t e r the appl icat ion o f 75 b l o w s (25 for each l i f t) , the c o m p a c t i o n c e l l was r e m o v e d f r o m the c o m p a c t i o n apparatus. T h e top and bot tom were t r i m m e d w i t h a straight edge to remove excess s o i l (about 3 m m o n the top o f the c e l l and 0.5 m m o n the bottom). 3.4.3 Hydraulic conductivity testing T h e compaction/permeameter c e l l was transferred to the permeameter. T h e reservoirs were pressurized w i t h compressed air control led b y regulators and m o n i t o r e d through gauges m o u n t e d o n the reservoirs. A l l head was suppl ied b y air pressure, w h i c h var ied f r o m 13.8 to 103.4 k P a . A i r pressure o f these magnitudes produced hydraul ic head v a r y i n g f r o m 27.6 to 207.0 over the 5.08 c m height o f the permeameter c e l l . T h e permeameter cells were fed f r o m bottom to top and the effluent was col lected i n glass bottles w i t h P T F E - l i n e d l ids . There were m a n y runs o f the k tests. Table 3.2 indicates the soi ls and permeants used for each run. T h e soils used i n each r u n are defined by the letters C or E . T h e letter C indicates that the s o i l used for that run was a control s o i l (contained no organoclay) , w h i l e the letter E indicates that the s o i l used for that r u n was an experimental s o i l (contained organoclay) . T h e def in i t ion o f the s o i l numbers (i.e., S o i l #1, #2, #3, and #4) is g i v e n beneath T a b l e 3.2. 43 Table 3.2: Summary of hydraulic conductivity runs Run Soil Permeant Duration of test (h) C l 1 0.01 M C a S 0 4 329 C 2 & C 3 1 0.01 M C a S 0 4 309 C 4 , C 5 & C 6 2 0.01 M C a C l 2 2017 C 7 1 0.01 M C a S 0 4 w i t h 10 m g / L P C P 576 C 8 1 0.01 M C a S 0 4 w i t h 10 m g / L P C P 2188 C 9 1 0.01 M C a S 0 4 w i t h 10 m g / L P C P 2071 C 1 0 , C 1 1 , & C 1 2 2 0.01 M C a C l 2 w i t h 10 m g / L P C P 709 C 1 3 & C 1 4 2 0.01 M C a C l 2 w i t h 10 m g / L N P 6 2 0 C 1 5 2 0.01 M C a C l 2 w i t h 10 m g / L N P 1254 C 1 6 & C 1 7 2 0.01 M C a C l 2 w i t h 10 m g / L N P 651 C 1 8 & C 1 9 2 0.01 M C a C l 2 w i t h 10 m g / L N P 1706 C 2 0 , C 2 1 . C 2 2 2 0.01 M C a C l 2 w i t h 30 m g / L T L 1558 C 2 3 , C 2 4 , C 2 5 2 0.01 M C a C l 2 w i t h 10 m g / L M E K 1581 E 1 . E 2 & E 3 3 0.01 M C a S 0 4 807 E 4 , E 5 & E 6 4 0.01 M C a C l 2 1341 E 7 , E 8 & E 9 3 0.01 M C a S 0 4 w i t h 10 m g / L P C P 1218 E 1 0 . E 1 1 & E 1 2 4 0.01 M C a C l 2 w i t h 10 m g / L P C P 286 E 1 3 4 0.01 M C a C l 2 w i t h 10 m g / L N P 291 E 1 4 & E 1 5 4 0.01 M C a C l 2 w i t h 10 m g / L N P 509 E 1 6 4 0.01 M C a C l 2 w i t h 10 m g / L N P 660 E 1 7 & E 1 8 4 0.01 M C a C l 2 w i t h 10 m g / L N P 4 8 0 E 1 9 , E 2 0 & E 2 1 4 0.01 M C a C l 2 w i t h 10 m g / L N P 1059 E 2 2 & E 2 4 4 0.01 M C a C l 2 w i t h 30 m g / L T L 556 E 2 3 4 0.01 M C a C l 2 w i t h 30 m g / L T L 840 E 2 5 4 0.01 M C a C l 2 w i t h 10 m g / L M E K 1431 E 2 6 4 0.01 M C a C l 2 w i t h 10 m g / L M E K 1383 E 2 7 4 0.01 M C a C l 2 w i t h 10 m g / L M E K 116 E 2 8 4 0.01 M C a C l 2 w i t h 10 m g / L M E K 1465 E 2 9 4 0.01 M C a C l 2 w i t h 10 m g / L M E K 503 E 3 0 4 0.01 M C a C l 2 w i t h 10 m g / L M E K 1010 N o t e : S o i l # 1: 8 8 . 0 % sand, 1 2 . 0 % untreated bentonite S o i l # 2: 92.5%) sand, 7 .5% untreated bentonite S o i l # 3: 8 8 . 0 % sand, 8 . 0 % untreated bentonite, 4 . 0 % organoclay S o i l # 4: 92.5% sand, 5 . 0 % untreated bentonite, 2 . 5 % organoclay 44 3.4.3.1 Pentachlorophenol S o l i d P C P was d isso lved at a concentration o f 10,000 m g / L i n methanol . 6.0 L o f 0 . 0 1 M C a S 0 4 or 0.01 M C a C l 2 was added to the reservoir, and 6.00 m L was w i t h d r a w n . A f t e r this , 6.00 m L o f the methanol so lut ion was added to the reservoir to give a 10 m g / L aqueous s o l u t i o n o f P C P . T h e p H o f the so lut ion i n the reservoir was adjusted to 10 to ensure a l l P C P was i n the i o n i z e d f o r m . F o r purposes o f preparations o f standards for G C analysis , 250 m L o f the 10 m g / L P C P solut ion was set aside outside the reservoir. T h i s l i q u i d was kept i n a 2 5 0 - m L glass bottle i n the same fume h o o d as the reservoir and permeameter. 3.4.3.2 Naphthalene S o l i d N P was d isso lved at a concentration o f 1,000 m g / L i n methanol . 6.0 L o f 0.01 M C a C l 2 so lut ion was added to the reservoir, and 60.0 m L was w i t h d r a w n . A f t e r this , 60.0 m L o f the methanol so lut ion was added to the reservoir to give a 10 m g / L aqueous so lut ion o f N P . F o r purposes o f preparations o f standards for G C analysis , 250 m L o f the 10 m g / L N P s o l u t i o n was set aside i n the same manner as described above for P C P . 3.4.3.3 Toluene A 2.00 L glass v o l u m e t r i c flask was f i l l e d w i t h 0.01 M C a C l 2 to w i t h i n 10 m L o f the f i l l l ine , then 69 u L (60 mg) o f pure T L was added to the flask. T h e flask was f i l l e d to the f i l l l ine w i t h 0.01 M C a C l 2 . A f t e r m i x i n g , the contents o f the flask were added to the reservoir. T h i s process was repeated w i t h two more flasks, to give a total o f 6.00 L o f 30 m g / L T L i n 0.01 M C a C l 2 i n the reservoir. A 250 m L sample o f the 30 m g / L T L so lut ion was taken f r o m the reservoir and set aside as had been done for N P and P C P . 45 3.4.3.4 Methyl Ethyl Ketone T h e same procedure was f o l l o w e d for M E K as was done for T L , except that o n l y 25 u L (20 m g ) was added to each 2.00 L volumetr ic flask, p r o d u c i n g 6.00 L o f 10 m g / L M E K i n 0.01 M C a C l 2 . 3.5 E F F L U E N T SAMPLING AND ANALYSIS Several steps were taken to m i n i m i z e problems w i t h v o l a t i l i z a t i o n o f the test chemica ls and/or evaporat ion o f the col lected effluent i n the k tests: • T h e permeant was placed i n the reservoirs as q u i c k l y as possible , after w h i c h the reservoirs were immediate ly sealed. • T h e c o l l e c t i o n bottles were almost complete ly sealed. T h e caps o f these bottles, however , had to be left s l ight ly loose to a l l o w a s m a l l amount o f air f l o w . I f this was not done, air pressure bui l t up inside the bottles and decreased the rate o f f l o w through the leaching cel ls . • O n c e col lected, the effluent samples were stored w i t h zero headspace. 3.5.1 Pentachlorophenol It was necessary to obtain a 5.0 m L effluent sample for G C analysis (see A p p e n d i x I). H o w e v e r , there was often less than 5.0 m L avai lable f r o m the effluent f r o m cel ls conta in ing contro l soi ls (i.e., w i t h no organoclay) , since these soils had very l o w k. M e t h o d s for obta in ing 5.0 m L samples f r o m the effluent f r o m the k tests var ied depending o n whether 5.0 m L was avai lable or not. 1. I f the sample was less than 5 m L , it was poured into a 5.0 m L glass graduated cy l inder , and the v o l u m e i n the graduated cy l inder (e.g., 1.4 m L ) was recorded. 46 A f t e r this, enough 0.01 M C a C l 2 ( p H adjusted to 10) was added to b r i n g up the v o l u m e to 5.0 m L . C a l c u l a t i o n o f [ P C P ] i n the effluent took this d i l u t i o n into account. See A p p e n d i x I for explanation o f this procedure and the associated calculat ions. T h e sample was transferred to a 5.0 m L glass sample bottle w i t h a P T F E - l i n e d l i d and stored i n the dark w i t h zero headspace at 4° C . 2. I f the effluent available was equal to or greater than 5.0 m L , it was poured straight into a 5.0 m L glass sample bottle w i t h a P T F E - l i n e d l i d and stored i n the dark w i t h zero headspace at 4° C . P C P was extracted into hexane as described above i n 3.3.1 and analyzed o n a G C . See A p p e n d i x H for detailed G C condit ions. 3.5.2 Naphthalene C o l l e c t i o n o f effluent samples was the same as described i n 3.5.1 for the P C P samples. N P was extracted into methylene chlor ide as described above i n 3.3.2 and analyzed o n a G C . See A p p e n d i x H for detailed G C condit ions. 3.5.3 Toluene C o l l e c t i o n o f effluent samples was the same as described i n 3.5.1 for the P C P samples. T L was extracted into methylene chloride as described above i n 3.3.3 and analyzed o n a G C . See A p p e n d i x H for detailed G C condit ions. 3.5.4 Methyl Ethyl Ketone C o l l e c t i o n o f effluent samples was the same as described i n 3.5.1 for the P C P samples. Ef f luent samples were transferred to 2.0 m L glass G C via ls w i t h P T F E - l i n e d l ids and analyzed direct ly o n a G C . See A p p e n d i x H for detailed G C condit ions. 47 3.5.5 pH measurements W h e n e v e r possible , the p H o f the effluent i n the k tests was determined. It was often not poss ible to measure p H i f very s m a l l vo lumes o f effluent were avai lable, especial ly i f some o f this effluent had to be preserved for G C analysis. T h i s d i f f icul ty was most pronounced w i t h the contro l runs ( C 1 - C 2 5 ) because o f the l o w k o n most o f these runs. A l l p H measurements were done w i t h a B e c k m a n d)44 p H meter and an O a k t o n epoxy b o d y p H electrode. T h e results o f the effluent p H measurements are s h o w n i n the tables o f data for the k tests i n A p p e n d i x J , and d i s c u s s i o n o f these results is found i n A p p e n d i x F . 48 CHAPTER 4 RESULTS AND DISCUSSION 4.1 SOIL MATERIALS 4.1.1 Physical properties T h e phys ica l properties o f the various so i l materials are presented i n T a b l e 4.1. G r a i n size distributions for the bentonite, sand and organoclay are s h o w n i n F i g u r e 4.1. Table 4.1: Physical properties of soil materials Soil Specific Specific Liquid Maximum Optimum Organic material gravity surface limit dry water carbon (g/cm3) (m2/g) (H20 %) density content (% by (g/cm3) (H20 %) weight) Bentonite 2.64 462 146* n/a n/a 1.30 Sand 2.66 n/a n/a n/a n/a n/a Organo- 2.23 . 326 70 n/a n/a n/a c lay S o i l # 1 n/a n/a n/a 1.86 13.0 n/a S o i l # 2 2.65 n/a 20 1.82 14.0 n/a S o i l # 3 n/a n/a n/a 1.84 13.5 ' n/a S o i l # 4 2.62 n/a 19 1.78 14.0 n/a * T h e plastic l i m i t for bentonite was 7 0 % . It was not possible to determine plastic l i m i t for the other s o i l materials (see 3.1.2.4). N o t e : S o i l # 1: 88.0% sand, 12.0% untreated bentonite S o i l # 2: 92.5%o sand, 7 .5% untreated bentonite S o i l # 3: 88.0% sand, 8 .0% untreated bentonite, 4 .0% organoclay S o i l # 4: 92 .5% sand, 5 .0% untreated bentonite, 2 .5% organoclay 49 4.1.2 Physicochemical and mineralogical properties T h e p h y s i c o c h e m i c a l and minera log ica l properties o f the s o i l materials are s h o w n i n T a b l e 4.2. Table 4.2: Physicochemical and mineralogical properties of soil materials Soil material pH in distilled pH in 0.01 M C E C (cmol/kg) Basal spacing water C a C l 2 (A) Bentonite 8.38 7.61 59.0 11.2 Sand 4.72 7.67 0.2 n/a Organoclay 7.94 7.69 n/a 16.5 Deta i led results and discuss ion o f s o i l phys ica l and p h y s i c o c h e m i c a l properties can be rev iewed i n A p p e n d i c e s A - G . 4.2 ADSORPTION C H A R A C T E R I S T I C S 4.2.1 Pentachlorophenol A s the p K a o f P C P is 4.75, most P C P i n a solut ion w i t h p H » 4.75 w o u l d be found i n the anionic f o r m . H o w e v e r , i n a solut ion w i t h p H « 4.75, most P C P w o u l d be n o n - i o n i z e d (Stapleton et a l , 1994). T o understand the adsorption o f anionic and n o n i o n i c P C P o n the organoclay and the bentonite, batch adsorption tests were done at p H 4.0 and p H 10.0. T h e adsorption isotherms for P C P o n organoclay and bentonite i n a p H 4.0 solut ion are s h o w n i n Figure 4.2. A t an i n i t i a l [ P C P ] o f 10 m g / L i n the batch, organoclay adsorbed m o r e than 78,000 m g o f P C P per k g o f clay. Bentonite , i n compar ison, adsorbed about 2700 m g P C P per k g o f c lay at this i n i t i a l [ P C P ] . T h u s , organoclay adsorbed about 30 times more P C P per unit weight than d i d bentonite. 50 80000 Initial [PCP] (mg/L) Figure 4.2 : Adsorption o f PCP by organoclay a n d b e n t o n i t e at pH 4.0 51 T h e adsorption isotherms for P C P o n organoclay and bentonite i n a p H 10.0 so lut ion are s h o w n i n F igure 4.3. A t an i n i t i a l [ P C P ] o f 10 mg/L i n the batch, organoclay adsorbed more than 24 ,000 m g o f P C P per k g o f clay. Bentonite , i n comparison, adsorbed about 560 m g P C P per k g o f c lay at this i n i t i a l [ P C P ] . Thus , organoclay adsorbed more than 40 t imes more P C P per unit weight than d i d bentonite. B o y d et a l (1988) d i d a batch adsorption test w i t h H D T M A - m o d i f i e d bentonite and P C P at two different p H ' s , 5.5 and 10.0. A d s o r p t i o n was only s l ight ly higher for the batch test at p H 5.5 than it was for the test done at p H 10.0. T h i s c o u l d be accounted for by the fact that p H 5.5 is s t i l l s igni f icant ly higher than the p K a o f 4.75, so that most o f the P C P w o u l d be i n the i o n i z e d f o r m , though there w o u l d be more n o n - i o n i z e d P C P present than w o u l d be the case at p H 10.0. T h e highest adsorption they found at p H 5.5 was s l ightly less than 32,000 mg/kg, w h i l e the adsorption at p H 10.0 was about 26,600 mg/kg. T h e adsorption result at p H 10.0 o f B o y d et a l (1988) is comparable to the results i n the present study (>24,000 mg/kg at p H 10.0) H o w e v e r , the s o d i u m bentonite they used to prepare the organoclay had a cat ion exchange capacity ( C E C ) o f 90 cmol/kg , a l l o f w h i c h was o c c u p i e d by H D T M A . T h e bentonite used i n the present study had a C E C o f 59 cmol/kg. O n l y 7 0 % o f the C E C (40 cmol/kg) was occupied by H D T M A o n the organoclay. T a k i n g these facts into account, it can be conc luded that the organoclay i n the present study adsorbed i o n i z e d P C P better than the organoclay produced by B o y d et a l (1988). Stapleton et al (1994) also used a s o d i u m bentonite i n batch adsorption tests w i t h P C P at different p H ' s . A t p H 4.1, adsorption was about 160,000 m g P C P / k g organoclay, w h i l e at p H 8.5, adsorption was about 66,500 m g P C P / k g organoclay. 52 25000 Initial [PCP] (mg/L) Figure 4.3: Adsorption of PCP by organoclay and bentonite at pH 10.0 In the present study, 78,000 m g P C P / k g organoclay were adsorbed at p H 4.0 -approximately h a l f o f the value observed by Stapleton et al (1994), w h o replaced the entire C E C o f a s o d i u m bentonite o f 90 cmol/kg w i t h H D T M A . T h i s is reasonable, since o n l y h a l f as m u c h H D T M A (40 cmol/kg) was avai lable i n the present study. A t p H 10.0, an adsorption o f 24,000 m g P C P / k g organoclay was obtained i n the present study, m u c h less than h a l f o f the adsorption achieved by Stapleton et a l (1994) at p H 8.5. H o w e v e r , Stapleton et a l (1994) used h i g h i n i t i a l P C P concentrations (up to 53 mg/L) at h i g h p H values, at w h i c h P C P is not only i o n i z e d but more soluble. In the present study, the highest in i t ia l P C P concentration used was 10 mg/L. T h i s accounts for the higher adsorption achieved by Stapleton et a l (1994). A t l o w p H , P C P is a very s l ightly soluble c o m p o u n d (about 14 mg/L) and can therefore be characterized as more hydrophobic than any o f the other test chemicals used i n the present study. H o w e v e r , as p H increases, P C P can be as soluble as 2.0 x 10 5 m g / L (Crosby et a l , 1981). Therefore, at higher p H P C P can be characterized as being very h y d r o p h i l i c . Despite this h y d r o p h i l i c i t y , i o n i c P C P is adsorbed m u c h better o n organoclay than any o f the other test chemicals used (see 4.2.2 to 4.2.4 be low) . T h i s observation does not agree w i t h the c o n c l u s i o n o f many researchers that organic chemicals are adsorbed by organoclays i n proport ion to the chemical 's hydrophobic i ty (e.g., M o r t l a n d et a l , 1986; Dente l et a l , 1995; L o and Li l jestrand, 1996). It is generally accepted that a part i t ioning m e c h a n i s m , i n w h i c h a hydrophobic organic c h e m i c a l is adsorbed b y the hydrophobic pseudophase created at the c lay surface by H D T M A , is responsible for the adsorption o f organic chemicals by organoclays ( B o y d et a l , 1991). T h e 54 adsorption o f i o n i z e d P C P and other organic ions such as d i c a m b a (Zhao et a l , 1996) suggests that other mechanisms may also be operating. O n e m e c h a n i s m w h i c h may account for the adsorption o f organic anions was suggested by C a p o v i l l a et a l (1991). T h e y conc luded that anionic dodecyl sulfate (DS") was adsorbed by organoclay through v a n der W a a l s interactions between the hydrophobic tails o f D S " ions and the hydrophobic tails o f the cat ionic surfactant adsorbed to the c lay surface, w i t h the a n i o n i c sulfonate head groups o f D S " protruding into the aqueous phase. T h i s phenomenon is also referred to as hydrophobic b o n d i n g ( X u and B o y d , 1995). S u c h a m e c h a n i s m m a y be p lausible for anionic P C P as w e l l ( X u et a l , 1997). T h e m a i n di f f icul ty w i t h this argument is the repuls ion between the anionic head groups o f the P C P molecules adsorbed o n the surface. T h i s repuls ion c o u l d be strong enough to counteract the attraction between the hydrophobic tails caused by v a n der W a a l s forces. H o w e v e r , both P C P and H D T M A are very large molecules and the attractive v a n der W a a l s forces, w h i c h operate over the large hydrophobic area o f these molecules , m a y be strong enough to counterbalance the repulsive force between the anionic heads. C o w a n and W h i t e (1958) found that a length o f 8 carbon atoms was needed to compensate for the repulsive forces between head groups o f a l k y l a m m o n i u m ions, corresponding to a m a x i m u m v a n der W a a l s contact area o f about 172 A2. X u et a l (1997) pointed out that P C P ' s v a n der W a a l s contact area can vary between 143 and 208 A 2, comparable to an a l k y l cha in w i t h 7-10 carbon atoms. It is also important to note that P C P molecules (and therefore their anionic head groups) w o u l d be relat ively isolated from one another. A t the m a x i m u m adsorption for anionic P C P (24,000 mg/kg), less than one H D T M A molecule i n ten w o u l d have a P C P molecule associated w i t h it. 55 T h e adsorption o f anionic P C P to organoclay through this m e c h a n i s m is i l lustrated i n F i g u r e 4.4 (a). It i s also possible that w h e n the c lay is treated w i t h H D T M A , some o f the surfactant molecules are adsorbed through hydrophobic b o n d i n g w i t h the tails o f surfactant molecules already adsorbed o n the c lay surface ( X u and B o y d , 1995). In this situation, anionic P C P c o u l d electrostatically b o n d w i t h the cat ionic head groups o f those surfactant molecules w h i c h are bound i n this manner. T h e adsorption o f anionic P C P to organoclay through this m e c h a n i s m is i l lustrated i n F igure 4.4 (b). There are also anion exchange sites o n clay, though most anions w i l l be repulsed by the great preponderance o f negatively charged cat ion exchange sites o n the c lay surface. H D T M A neutralizes the negative charge o f the cat ion exchange sites more effectively than inorganic cations ( X u et a l , 1997), so some anionic P C P may be adsorbed direct ly to a n i o n exchange sites on the clay surface. 4.2.2 Naphthalene T h e adsorption isotherms for N P o n organoclay and bentonite are s h o w n i n F igure 4.5. A t an i n i t i a l [ N P ] o f 10 m g / L i n the batch, organoclay adsorbed about 4400 m g o f N P per k g o f clay. Bentonite , i n compar ison, adsorbed about 500 m g N P per k g o f clay. Thus , organoclay adsorbed almost ten t imes more N P per unit weight than d i d bentonite. Jaynes and B o y d (1991) d i d batch adsorption tests w i t h N P o n a W y o m i n g bentonite w i t h a C E C o f 87 cmol/kg. H D T M A was added to this bentonite i n amounts equal to C E C , so that a l l cat ion exchange sites should have been occupied w i t h H D T M A . These authors f o u n d that the organoclay adsorbed about 8,300 m g N P / k g organoclay. T h i s result is consistent w i t h the present study since the bentonite used i n the present study had a l o w e r C E C (59 cmol/kg) , 56 Figure 4.4: Possible mechanisms for bonding of anionic PCP to organoclay. a) H y d r o p h o b i c P C P " tails b o n d w i t h hydrophobic tails o f H D T M A (hydrophobic bonding) . b) A n i o n i c head group o f P C P " bonds w i t h cat ionic head group o f H D T M A , w h i c h is i t se l f b o u n d through h y d r o p h o b i c b o n d i n g to the t a i l o f another H D T M A m o l e c u l e . T h e latter H D T M A m o l e c u l e is adsorbed o n the c lay surface through electrostatic b o n d i n g o n a cat ion exchange site. (Adapted f r o m C a p o v i l l a et a l , 1991) 57 and only 70% of the cation exchange sites (i.e., 40 cmol/kg) were occupied by HDTMA. Thus, one would expect the organoclay in the present study to adsorb about half as much as the organoclays used by Jaynes and Boyd (1991). 4.2.3 Toluene The adsorption isotherms for TL on organoclay and bentonite are shown in Figure 4.6. The concentrations of TL used were higher than those used for NP and PCP - both of the latter chemicals were tested at 10 mg/L maximum concentration in the batch adsorption test, while TL was tested at 100 mg/L maximum concentration. Organoclay was a much better adsorber than bentonite over the concentration range tested. At the maximum concentration of 100 mg/L, organoclay adsorbed 1079 mg TL/kg clay, while bentonite only adsorbed 70 mg TL/mg clay. This result is comparable with that of Jaynes and Boyd (1991), who also studied the adsorption of TL on HDTMA-modified bentonite. At an equilibrium concentration of 60 mg/L TL, the bentonite used by these researchers adsorbed about 3000 mg TL/kg clay. At this same equilibrium concentration, the organoclay in the present study adsorbed 1079 mg/kg. This is not an unreasonable difference, since the bentonite used by Jaynes and Boyd (1991) had a cation exchange capacity (CEC) of 87 cmol/kg, all of which was occupied by HDTMA. By contrast, the clay in the present study had a CEC of 59 cmol/kg, of which only 70%o (40 cmol/kg) was occupied by HDTMA. 4.2.4 Methyl ethyl ketone The adsorption isotherm for MEK is shown in Figure 4.7. Organoclay adsorbed up to 152 mg MEK/kg, while bentonite adsorbed up to 107 mg MEK/kg. This result was somewhat surprising, since MEK is a hydrophilic organic chemical and would be expected to be more highly adsorbed by bentonite and not adsorbed well by organoclay. 58 0 2 4 6 8 10 Initial [NP] (mg/L) Figure 4.5: Adsorption of NP by organoclay and bentonite 59 -4 Bentonite •a— Organoclay 0 2 4 6 8 10 Initial [MEK] (mg/L) F i g u r e 4.7: Adsorption of M E K by organoclay and b e n t o n i t e O n e explanat ion for this may be that the c lay surface environment created by H D T M A is not o n l y hydrophobic but also organophi l ic . T h e organophi l ic i ty o f the organoclay for the organic M E K molecules m a y have been strong enough to overcome m u c h o f the repuls ion caused by the organoclay's hydrophobic i ty . 4.3 H Y D R A U L I C C O N D U C T I V I T Y TESTING T h e results o f the hydraul ic conduct iv i ty tests are s u m m a r i z e d i n Table 4 .3 . There are several ways to analyze these results. F irst , they can be l o o k e d at as ranges, i.e., the highest and lowest k values observed dur ing the runs. T h e mean k over any one r u n (e.g., r u n C l ) can be obtained by tak ing the mean o f a l l the k readings f r o m that run. A mean value for a group o f s i m i l a r runs (e.g., a l l the runs w h i c h used s o i l # 3 w i t h a permeant o f 0.01 M C a C b w i t h 10 m g / L N P ) can then be obtained by averaging the averages f r o m each run. T h i s is the value s h o w n i n Table 4.3 as "overal l mean k." A n o t h e r w a y to obtain a g lobal mean is to take the mean o f a l l the i n d i v i d u a l readings f r o m a group o f s imi lar runs. T h i s is the figure s h o w n i n Table 4.3 as "mean k o f a l l readings." T h e second method o f ca lculat ing the mean gives more weight to longer runs ( w h i c h had more i n d i v i d u a l readings), w h i l e the first method gives equal weight to a l l runs, regardless o f length. In many cases, the two methods give the same result; this is usual ly because a l l runs i n the group were o f identical length. Deta i led results for a l l the hydraul ic conduct iv i ty tests are tabulated i n A p p e n d i x J . 61 Table 4.3: Results summary for hydraulic conductivity (k) tests Runs Lowest k (cm/s) Highest k (cm/s) Overall mean k (cm/s) Mean k of all readings 10"8 8.7 x 10"8 10 "8 4.8 x l O " 8 10"8 1.1 x 10"8 10"8 2.2 x IO" 8 io- 7 7.4 x 10"8 IO" 7 1.5 x 10"7 IO" 8 2.2 x IO" 8 10 "7 3.5 x 10 "7 10"7 7.4 x 10"7 IO" 7 1.8 x 10"7 I O - 6 2.1 x IO" 6 io- 7 , 9.9 x l O " 7 IO" 7 8.5 x l O " 7 IO" 7 6.9 x 10"7 C1,C2, C3 1.9 x 10"8 2.7 x 10"7 C4, C5, C6 8.4 x 10"9 2.1 x 10"7 Cl, C8, C9 1.2 x l O " 9 1.3 x l O " 7 C10,C11,C12 1.1 x IO" 8 9.6 x 10"8 C13-C19 7.6 x 10"9 1.2 x 10"6 C20, C21,C22 . 7.4 x l O " 9 1.2 x 10"6 C23, C24, C25 1.0 x IO" 8 6.4 x 10"8 E1,E2, E3 9.9 x IO" 8 1.0 x 10"6 E4, E5, E6 4.2 x IO" 7 1.2 x 10"6 E7, E8, E9 1.3 x 10"7 3.5 x I O - 7 E10,E11,E12 8.8 x 10"7 5.6 x 10"6 E13-E21 1.1 x 10"7 4.2 x 10"6 E22, E23, E24 2.4 x 10'7 5.3 x 10"6 E25-E30 1.9 x 10"9 2.0 x 10"6 4.3.1 Control tests T h e results o f the k tests done w i t h so i l # 1 (88.0% sand, 12.0% bentonite) w h e n permeated w i t h 0.01 M CaS04 are s h o w n i n Figure 4.8. These runs had k values ranging between 1.9 x IO" 8 and 2.7 x IO" 7 cm/s. T h e results o f the k tests done w i t h s o i l # 2 (92.5% sand, 7.5% bentonite) w h e n permeated w i t h 0.01 M CaCh are s h o w n i n Figure 4.9. These runs had k values ranging between 8.4 x 10"9 and 2.1 x 10"7 cm/s. T h e results o f the A; tests done w i t h so i l # 3 (88.0% sand, 8.0% bentonite and 4.0% organoclay) w h e n permeated w i t h 0.01 M CaS04 are s h o w n i n Figure 4.10. These runs had k values ranging between 9.9 x 10" and 1.0 x 10" cm/s. B a s e d o n overal l means, the experimental runs had k values approximately 4 t imes greater than the control s o i l . 62 1.00E-06 _ Figure 4.9: Hydraulic conductivity of Runs C4, C5 & C6 63 T h e results o f the £ tests done w i t h s o i l # 4 ( 9 2 . 5 % sand, 5 . 0 % bentonite, 2 . 5 % organoclay) w h e n permeated w i t h 0.01 M C a C b are s h o w n i n Figure 4.11. These runs had k 7 ft values ranging between 4.2 x 10" and 1.2 x 10" cm/s. B a s e d o n overal l means, the experimental runs had k values approximately 15 times greater than the control s o i l . F r o m the results o f these control runs, it is apparent that the presence o f organoclay i n the s o i l caused a large increase i n k, wi thout the presence o f any organic chemicals i n the permeant. T h i s agrees w i t h the f indings o f other researchers ( S m i t h et a l , 1992; S m i t h and Jaffe, 1994; W a l l a c e et a l , 1995; B u d h u et a l , 1997). 4.3.2 Pentachlorophenol R u n s C 7 , C 8 and C 9 used 0.01 M C a S 0 4 w i t h 10 m g / L P C P to permeate so i l # 1 ( 8 8 . 0 % sand, 1 2 . 0 % bentonite). The var iat ion i n A: over t ime is s h o w n i n Figure 4.12. These 9 7 runs had k values ranging between 1.2 x 10" and 1.3 x 10" cm/s. R u n s C 1 0 , C l 1 and C 1 2 used 0.01 M C a C l 2 w i t h 10 m g / L P C P to permeate s o i l # 2 ( 9 2 . 5 % sand, 7.5% bentonite). T h e var iat ion o f k w i t h t ime is s h o w n i n F i g u r e 4.13. These runs had k values ranging between 1.1 x 10"8 and 9.6 x 10"8 cm/s, C o m p a r e d to R u n s C 7 , C 8 and C 9 ( w h i c h used 0.01 M CaSG-4 rather than 0.01 M C a C k ) , k nearly doubled based o n overal l m e a n k. H o w e v e r , these runs ( C 1 0 , C l 1 and C 1 2 ) used so i l # 2 rather than s o i l # 1. A s s igni f icant ly less c lay was i n c l u d e d i n s o i l # 2, it was expected that k w o u l d increase. R u n s E 7 , E 8 and E 9 used 0.01 M C a S 0 4 w i t h 10 m g / L P C P to permeate so i l # 3 ( 8 8 . 0 % sand, 8 . 0 % bentonite, 4 . 0 % organoclay). T h e var iat ion i n k over t ime is s h o w n i n Figure 4.14. These runs had k values ranging between 1.3 x 10" 7 and 3.5 x 10" 7 cm/s. B a s e d o n overa l l means, the experimental runs had k values approximately 14 t imes greater than the control s o i l . 64 Figure 4.10: Hydraulic conductivity of Runs E1, E2 & E3 Figure 4.11: Hydraulic conductivity of Runs E4, E5, and E6 65 1.00E-06 1.00E-07 1.00E-08 1.00E-09 500 1000 1500 Time (h) 2000 2500 Figure 4.12: Hydraulic conductivity of Runs C7, C8 and C9 1.00E-06 1.00E-07 1.00E-08 Figure 4.13: Hydraulic conductivity of RunsCIO, C11 and C12 R u n s E 1 0 , E11 and E 1 2 used 0.01 M C a C l 2 w i t h 10 m g / L P C P to permeate s o i l # 4 ( 9 2 . 5 % sand, 5 . 0 % bentonite, 2 . 5 % organoclay). The var iat ion o f k w i t h t ime is s h o w n i n 7 6 F i g u r e 4.15. These runs had k values ranging between 8.8 x 10" and 5.6 x 10" cm/s. B a s e d o n overal l means, the experimental runs had k values approximately 95 t imes greater than the control s o i l . 4.3.3 Naphthalene R u n s C 1 3 to C 1 9 used 0.01 M C a C l 2 w i t h 10 m g / L N P to permeate so i l # 2 ( 9 2 . 5 % sand, 7 . 5 % bentonite). T h e var iat ion o f k w i t h t ime is s h o w n i n F igure 4.16. These runs h a d k values ranging between 7.6 x 10" 9 and 1.2 x 10" 6 cm/s. R u n s E 1 3 to E 2 1 used 0.01 M C a C l 2 w i t h 10 m g / L N P to permeate s o i l # 4 ( 9 2 . 5 % sand, 5 . 0 % bentonite, 2 . 5 % organoclay). T h e var iat ion i n k w i t h t ime is s h o w n i n F igure 4.17. These runs had l v a l u e s ranging between 1.1 x 10" 7 and 4.2 x 10" 6 cm/s. O v e r a l l mean k was approximately 9 t imes higher for these experimental runs than for the control runs (C13 to C 1 9 ) . 4.3.4 Toluene R u n s C 2 0 , C 2 1 and C 2 2 used 0.01 M C a C l 2 w i t h 30 m g / L T L to permeate so i l # 2 ( 9 2 . 5 % sand, 7 . 5 % bentonite). T h e var iat ion o f k w i t h t ime is s h o w n i n F igure 4.18. These runs had k values ranging between 7.4 x 10" 9 and 1.2 x 10" 6 cm/s. R u n s E 2 2 , 23 and 24 used 0.01 M C a C l 2 w i t h 30 m g / L T L to permeate so i l # 4 ( 9 2 . 5 % sand, 5.0%) bentonite, 2.5%) organoclay). T h e var iat ion o f k w i t h t ime is s h o w n i n F igure 4.19. These runs had k values ranging between 2.4 x 10" 7 and 5.3 x 10" 6 cm/s. O v e r a l l mean k was approximately 6 t imes higher for these experimental runs than for the control runs ( C 2 0 , C 2 1 and C 2 2 ) . 67 ) 1.00E-06 Figure 4.14: Hydraulic conductivity of Runs E7, E8 and E9 1.00E-05 Figure 4.15: Hydraulic conductivity of Runs E10, E11 and E12 68 in E > o 2 •a c o u o 3 CO k_ 73 >. X 1.00E-05 1.00E-06 1.00E-07 1.00E-08 LOOE-09 200 400 600 800 1000 1200 1400 1600 Time (h) Figure 4.16: Hydraulic conductivity of RunsC13-C19 Figure 4.17: Hydraulic conductivity of Runs E13-21 1.00E-05 1.00E-09 Figure 4.18: Hydraulic conductivity of Runs C20, C21 and C22 1.00E-05 o 3 T3 C O o o "5 2 •a >. x 1.00E-06 1.00E-I 0 100 200 300 400 500 600 700 800 900 Time (h) Figure 4.19: Hydraulic conductivity of Runs E22, E23, and E24 4.3.5 Methyl ethyl ketone R u n s C 2 3 , C 2 4 and C 2 5 used 0.01 M C a C l 2 w i t h 10 m g / L M E K to permeate so i l # 2 ( 9 2 . 5 % sand, 7 . 5 % bentonite). T h e var iat ion o f k w i t h t ime is s h o w n i n Figure 4.20. These runs had k values ranging between 1.0 x 10"8 and 6.4 x 10"8 cm/s. R u n s E 2 5 to E 3 0 used 0.01 M C a C l 2 w i t h 10 m g / L M E K to permeate s o i l # 4 ( 9 2 . 5 % sand, 5 . 0 % bentonite, 2 . 5 % organoclay). T h e var iat ion o f k w i t h t ime is s h o w n i n F i g u r e 4.21 . These runs had k values ranging between 1.9 x 10" 9 and 2.0 x 10" 6 cm/s. O v e r a l l m e a n k was approximately 39 times higher for these experimental runs than for the control runs ( C 2 3 , C 2 4 a n d C 2 5 ) . 4.4 E F F E C T O F T E S T C H E M I C A L S O N H Y D R A U L I C C O N D U C T I V I T Y 4.4.1 Pentachlorophenol R u n s C 7 , C 8 and C 9 had an overal l average k approximately one seventh that o f R u n s C l , C 2 and C 3 ( w h i c h used the same s o i l and the same permeant, without the 10 m g / L P C P ) . T h e results o f these runs, therefore, indicate that the presence o f 10 m g / L P C P i n the permeant decreased k. R u n s C 1 0 , C l 1 and C 1 2 had a n overa l l average k less than h a l f that o f R u n s C 4 , C 5 , a n d C 6 ( w h i c h used the same so i l and the same permeant, without the 10 m g / L P C P ) . These results also indicate that the presence o f 10 m g / L P C P i n the permeant decreased k. R u n s E 7 , E 8 , and E 9 had an overal l average k s l ight ly more than h a l f that o f R u n s E l , E 2 and E 3 ( w h i c h used the same s o i l and the same permeant, without the 10 m g / L P C P ) . These results also indicate that the presence o f 10 m g / L P C P i n the permeant decreased k. 71 Figure 4.20: Hydraulic conductivity of RunsC23, C24 and C25 Figure 4.21: Hydraulic conductivity of Runs E25-E30 72 T h e presence o f 10 m g / L P C P i n R u n s E 1 0 , E l l , and E 1 2 increased A: rather than decreasing it; k was almost 3 times higher than i n R u n s E 4 , E 5 and E 6 ( w h i c h used the same s o i l and the same permeant, without the 10 m g / L P C P ) . 4.4.2 Naphthalene In some o f the control runs, the presence o f N P i n the effluent was associated w i t h h i g h k. F igure 4.22 shows the variat ion i n k for R u n s C 1 3 , C 1 4 and C 1 5 , and Figure 4.23 shows the var iat ion i n [ N P ] for the same runs. N o t i c e that R u n C 1 5 has litt le or no N P i n the effluent throughout the run, and also has very l o w k throughout the run. R u n C 1 4 has higher k and higher [ N P ] throughout most o f the r u n compared to C 1 3 and C 1 5 . R u n C 1 3 has h i g h k and h i g h [ N P ] at the beg inning o f the run, w h i l e both k and [ N P ] decl ine i n the latter part o f the run. T h e last data point for R u n C 1 3 shows an increase i n both k and [ N P ] . It was observed that N P breakthrough i n the experimental soils was accompanied by an increase i n k, perhaps indicat ing that the N P caused the so i l to shrink once the s o i l was saturated w i t h N P . T h i s phenomenon is somewhat obscured i n F igure 4.17 because o f the logar i thmic scale o f the graph and because a l l these runs are presented together. T o better demonstrate the increase i n k w i t h N P breakthrough, the data is presented o n a regular scale and i n subgroups i n Figures 4.24, 4.25, and 4.26. T h e subgroups are those groups o f runs that ran at the same t ime. T h e point o f N P breakthrough is noted o n the graphs and is associated w i t h an increase i n k i n a l l 9 runs. T h i s is the opposite effect to that observed w i t h M E K (see 4.4.4 be low) , w h i c h caused a drop i n hydraul ic conduct iv i ty once M E K had saturated the s o i l . 73 1.00E-05 at E > 1.00E-06 '> O 3 •a c o o .2 1.00E-07 3 CO k-T3 >. X 1.00E-08 600 800 Time (h) Figure 4.22: Hydraulic conductivity of runsC13, C14 and C15 7.00 j 6.00 - -5.00 - -D) 4.00 - -B 3.00 -z 2.00 • 1.00 - -0.00 - -- • — C 1 3 -m— c u - A — C 1 5 0 200 400 600 800 1000 1200 1400 Time (h) Figure 4.23: Variation in [NP] with time for runsC13, C14, and C15 74 > o 3 T J C O o o "5 ra i— T J >> X 4 . 5 0 E - 0 6 4 . 0 0 E - 0 6 3 . 5 0 E - 0 6 6 0 0 Figure 4.24: Hydraulic conductivity of Runs E10, E11 and E12 (A E o > o 3 TJ C O o o "5 2 T J >. X 2 . 5 0 E - 0 6 2 . 0 0 E - 0 6 1 . 5 0 E - 0 6 1 . 0 0 E - 0 6 1 5 . 0 0 E - 0 7 0 . 0 0 E + O 0 1 0 0 2 0 0 3 0 0 4 0 0 Time (h) 5 0 0 6 0 0 7 0 0 Figure 4.25: Hydraulic conductivity of Runs E13, E14 and E15 Figure 4.26: Hydraulic conductivity of runs E16, E17 and E18 4.4.3 Toluene I n the control runs ( C 2 0 , C 2 1 and C 2 2 ) , overa l l m e a n k was approximate ly 3 t imes greater than i n the runs w h i c h used the same s o i l and permeant, but without 30 m g / L T L ( C 4 , C 5 and C 6 ) . In the experimental runs ( E 2 2 , E 2 3 and E 2 4 ) , overal l mean k was o n l y s l ight ly higher than the runs w h i c h used the same s o i l and permeant, but without 30 m g / L T L ( E 4 , E 5 and E 6 ) - 8.9 x 10" 7 cm/s vs. 7.4 x 10" 7 cm/s. H o w e v e r , the experimental runs w i t h 30 m g / L T L s h o w a gradually increasing k throughout the run, w i t h a point reached where k increased so dramatical ly that the runs had to be stopped (see Figure 4.19). In fact, the experimental runs w i t h T L lasted o n l y for 547 h ( E 2 2 and E 2 4 ) and 840 h ( E 2 3 ) , w h i l e the experimental runs without T L a l l lasted for 1341 h and maintained a relatively stable A: throughout (see F i g u r e 4.11). T h i s phenomenon indicates that the presence o f 30 m g / L T L caused a sharp increase i n k for the soils containing organoclay. 4.4.4 Methyl ethyl ketone In the control runs ( C 2 3 , C 2 4 and C 2 5 ) , overal l mean k was less than h a l f that o f the runs w h i c h used the same soi l and permeant, but without 10 m g / L M E K ( C 4 , C 5 and C 6 ) . H o w e v e r , a c o m p a r i s o n o f the graphs for these two groups o f runs (Figure 4.20 vs. F i g u r e 4.9) does not reveal any c o n v i n c i n g pattern o f difference i n k. O v e r a l l mean k for the experimental runs ( E 2 5 - E 3 0 ) was 8.1 x 10" 7 cm/s, almost the same as the overa l l mean k for the runs that used the same so i l and permeant, but without 10 m g / L M E K ( E 4 , E 5 and E 6 , w h i c h h a d an overa l l m e a n k o f 7.4 x 10" 7 cm/s). H o w e v e r , it is necessary to examine the graphs (Figure 4.21 vs. Figure 4.11) to beg in to make any conclus ions 77 about the effect o f M E K o n k. T h e results for M E K are m u c h more var ied than for any o f the other test chemicals , but there are some important observations that can be made: • There was no r u n i n w h i c h k remained stable or gradually increasing for a t ime, then suddenly increased, causing the run to be ended, as was the case w i t h T L and N P . • T h e overal l trend was for a decrease i n k over the course o f these runs, rather than an increase. • T h e three runs w h i c h ran for the longest t imes ( E 2 5 , E 2 6 and E 2 8 ) showed very s i m i l a r patterns o f var iat ion i n k. These runs are discussed b e l o w and are s h o w n as a group i n F igure 4.27. In r u n E 2 5 , signif icant concentrations o f M E K began to be detected i n the effluent at the same t ime as a large increase i n k occurred. M E K continued to be detected i n the effluent for 360 h , dur ing w h i c h t ime k gradually decl ined. Af ter this t ime, k dropped sharply, and M E K also disappeared f r o m the effluent. W h a t appears to have happened i n r u n E 2 5 is that M E K i n i t i a l l y caused an increase i n k, but w h e n M E K had saturated the s o i l , s w e l l i n g occurred, causing k to drop suddenly, and s l o w i n g f l o w through the c e l l . S ince the permeant was f l o w i n g through the ce l l m u c h more s l o w l y , the M E K i n the permeant had more t ime to adsorb to the s o i l and/or to vo la t i l i ze . R u n E 2 8 exhibi ted a s i m i l a r pattern to run E 2 5 , except that M E K i n the effluent d i d not appear i n the same way. It should be noted that a sharp increase i n k at about 1000 h occurred because o f an accidental air pressure increase, w h i c h caused some short-circuit ing. F i v e data points were affected by this pressure increase, and M E K appeared i n the effluent i n the p e r i o d immediate ly f o l l o w i n g the increase. I f the per iod affected by the pressure increase is disregarded, the pattern is very s imi lar to r u n E 2 5 . 78 After the commencement r u n o f r u n E 2 8 , k rapidly increased, then stayed relat ively constant for 410 h , then dropped and stayed at a m u c h lower level for the rest o f the run. N o M E K was detected i n the effluent at any t ime except dur ing the per iod affected by the pressure increase. T h e pattern o f change i n k is very s i m i l a r to run E 2 5 , but no M E K was found i n the effluent. S ince f l o w through this c e l l was m u c h l o w e r over the entire r u n than was the case i n r u n E 2 5 , the absence o f M E K f r o m the effluent is not surpris ing. T h e M E K w o u l d have had enough t ime i n the c e l l to adsorb to the so i l and/or vo la t i l i ze as mentioned above for r u n E 2 5 . H o w e v e r , the fact that M E K was present caused a s imi lar pattern o f change i n k. R u n E 2 6 remained at a l o w and relatively stable k unt i l about 930 h , at w h i c h t ime k f e l l to very l o w levels (as l o w as 1.89 x 10"9 cm/s). It w o u l d have taken longer for M E K to saturate the s o i l and cause s w e l l i n g i n this c e l l because o f the lower f low. O n c e the c e l l was saturated w i t h M E K , the already l o w k dropped to even lower levels, again suggesting s w e l l i n g caused by the presence o f M E K . T h e other two runs i n this group ( E 2 7 and E 3 0 ) provide l itt le useful in format ion. R u n E 2 7 had to be stopped after 116 h because o f very h i g h f l o w , probably caused by s i d e w a l l leakage i n the c e l l . R u n E 3 0 d i d not start running u n t i l 475 h had elapsed, so it was real ly o n l y i n the m i d d l e o f its course w h e n it was stopped. It c o u l d be that i f run E 3 0 had been cont inued, a s i m i l a r pattern to runs E 2 5 and E 2 8 w o u l d have been observed, w i t h a large drop i n k after M E K had saturated the s o i l . There was some detection o f M E K i n the effluent f r o m r u n E 3 0 . Af ter 599 h (i.e., 124 h after run E 3 0 started running), there was [ M E K ] i n the effluent o f 1.3 mg/L. Af ter 624 h (i.e., 149 h after run E 3 0 started running), there was [ M E K ] i n the effluent o f 1.2 mg/L. Other than these two readings, no M E K was detected i n the effluent o f r u n E 3 0 . 79 4.4.5 Summary of hydraulic conductivity results T h o u g h there is m u c h var iat ion between different runs us ing the same s o i l , permeant, and test c h e m i c a l , it is possible to make the f o l l o w i n g conclusions: 1. W h e n permeated w i t h 0.01 M CaSCv containing no organic chemicals , the presence o f 4 . 0 % organoclay i n the so i l increased k by four t imes compared to so i l that contained no organoclay. W h e n permeated w i t h 0.01 M C a C b conta ining no organic chemicals , the presence o f 2.5% organoclay increased & by 15 t imes compared to so i l that contained no organoclay. 2. W h e n the permeant had a concentration o f 10 m g / L P C P , the k o f control soi ls was decreased as compared to the same soi ls w h e n the permeant contained no P C P . 3. W h e n the permeant had a concentration o f 10 m g / L P C P , the k o f some experimental soi ls was decreased as compared to the same soi ls w h e n the permeant contained no P C P . Other experimental soi ls had higher k w h e n the permeant had a concentration o f 10 m g / L P C P than w h e n the permeant contained no P C P . 4. A concentration o f 10 mg/L N P i n the permeant caused increased k i n both the control and experimental soi ls , though this effect was more pronounced w i t h the experimental soi ls . 5. A concentration o f 30 m g / L T L i n the permeant caused increased k i n both the control and experimental soi ls , though this effect was more pronounced w i t h the experimental soi ls . 6. A concentration o f 10 m g / L M E K i n the permeant had no obvious effect o n k i n the control soi ls , but caused a decrease i n k i n the experimental soi ls . 80 In the context o f the present study, it is important to compare the k results o f the runs w i t h N P or T L w i t h the k results o f the relevant runs done w i t h no test chemicals present i n the permeant ( C 4 , C 5 and C 6 for the contro l soi ls ; E 4 , E 5 and E 6 for the experimental runs). It is evident f r o m figure 4.9 than runs C 4 , C 5 and C 6 had very l o w and stable k for more than 2 0 0 0 h . C o m p a r e this w i t h figures 4.22 and 4.18 - k is unstable and higher w h e n N P or T L are present. T h e experimental runs are also quite stable over a l o n g t ime p e r i o d w h e n no test chemicals are present i n the permeant (figure 4.11). C o m p a r e this w i t h figures 4.17 and 4.19 -both N P and T L have dramatic effects onk. 4.5 ADSORPTIVITY O F C L A Y BARRIER M A T E R I A L F O R T E S T C H E M I C A L S In this section, the results f r o m the effluent tests are e x a m i n e d to attempt to d iscover whether organoclay adsorbed test chemicals better i n compacted c lay barrier material than bentonite d i d i n the same material . It has been generally assumed that the results o f batch adsorption tests w i t h organoclay c o u l d be extrapolated to organoclay incorporated i n c lay barriers (e.g., B o y d et a l , 1991). T h i s assumption has not been tested i n pr ior research. It must be remembered that both organoclay and bentonite have finite adsorption capacities for the test chemicals . O n c e this adsorption capacity has been reached, no more o f the c h e m i c a l w i l l be adsorbed. Therefore, it is useful to consider the total v o l u m e o f permeant (and therefore total amount o f the test chemical) w h i c h passed through a sample. T o use t ime as an important factor w o u l d be a mistake. 81 T o illustrate this point w i t h an example , assume that P C P was detected i n the effluent o f one c e l l ( C e l l A ) after 720 h (30 d), w h i l e it was detected i n the effluent f r o m another c e l l ( C e l l B ) after 360 h (15 d). B o t h cel ls were permeated w i t h 0.01 M C a C l 2 w i t h 10 m g / L P C P . I f t i m e was considered the most important factor, it w o u l d be concluded that the c e l l A retained P C P better than c e l l B . H o w e v e r , the k o f ce l l A was 1 x 10"8 cm/s, so the flow o f permeant through c e l l A was only 106 m L i n 720 h . T h i s v o l u m e o f permeant w o u l d contain about 1 m g P C P . C e l l B had k = 3 x 10" 7 cm/s, so 1600 m L o f permeant flowed through it i n 360 h . T h i s means that about 16 m g o f P C P passed through c e l l B i n 3 6 0 h . S ince c e l l B adsorbed 16 m g o f P C P w h i l e c e l l A o n l y adsorbed 1 m g , it is more v a l i d to conclude that C e l l B adsorbed P C P better than ce l l A . 4.5.1 Pentachlorophenol Table 4.4 shows what v o l u m e o f permeant f l o w e d through each c e l l permeated w i t h 10 m g / L P C P before the c h e m i c a l was detected i n the effluent. I f P C P was not detected i n the effluent at a l l , this is indicated by n/b (no breakthrough), a long w i t h the total v o l u m e o f effluent w h i c h d i d flow through the c e l l . It is clear that m u c h greater vo lumes o f permeant flowed through experimental cel ls before P C P breakthrough than was the case w i t h control cel ls . T h i s shows that organoclay d i d adsorb P C P m u c h better i n compacted c lay barrier material than d i d bentonite i n the same compacted c lay barrier material . 82 Table 4.4: Breakthrough volumes for PCP runs Control run (no Breakthrough Experimental run Breakthrough organoclay) volume (mL) (containing volume (mL) organoclay) C 7 n / b - 4 5 . 0 E 7 n/b - 557.6 C 8 123.3 E 8 n / b - 5 7 0 . 1 C 9 80.1 E 9 n / b - 7 9 3 . 5 C I O 26.2 E 1 0 632.6 C l l 30.4 E l l 597.4 C 1 2 43.3 E 1 2 880.2 In the batch adsorption tests, organoclay adsorbed about 24,000 m g P C P / k g organoclay. T h e adsorption i n the hydraul ic conduct iv i ty tests was not nearly so h igh . F o r example, i n R u n E 1 2 , 880 m L o f permeant f l o w e d through the c e l l before P C P was detected. There w o u l d have been about 4.6 g o f organoclay i n the c e l l , and i f this organoclay a l l adsorbed P C P as w e l l as i n the batch adsorption tests, the c e l l should have been able to adsorb about 110 m g o f P C P . T h e c e l l , however, o n l y adsorbed the 8.8 m g o f P C P contained i n 880 m L o f permeant. There are several possible reasons for this difference i n adsorptivity. Preferential pathways may have existed w i t h i n the leaching ce l l . Less t ime m a y have been avai lable i n the leaching ce l l for e q u i l i b r i u m to be reached between organoclay and P C P . S o m e organoclay i n the leaching c e l l may not have come into contact w i t h P C P because the organoclay was contained i n a soi l matr ix w i t h a definite structure rather than i n an agitated solut ion, as is the case i n a batch adsorption test ( Y o n g et a l , 1992). In the leaching c e l l , dif fusive transport o f P C P to the organoclay may have been m u c h more important than was the case i n the batch adsorption tests, where P C P was brought into contact w i t h organoclay largely by advective transport. S ince d i f fus ion is generally a s lower process than advect ion, this m a y have been a reason for the decreased adsorptivity i n the leaching c e l l . 83 Organoclay i n compacted c lay barrier material adsorbs P C P m u c h better than bentonite i n the same compacted clay barrier material . H o w e v e r , one cannot take adsorption capacities f r o m batch adsorption tests and apply them direct ly to organoclay i n an actual c lay barrier. A c t u a l adsorption o f P C P m a y be m u c h l o w e r than indicated by the batch adsorption tests. H o w e v e r , this drop i n adsorption c o u l d be ameliorated by other factors such as l o w e r hydraul ic head, hydraul ic gradient and f l o w through an actual c lay barrier than was the case i n the c o l u m n leaching tests i n the present study. 4.5.2 Naphthalene T h e results o f the effluent tests f r o m the N P runs are s h o w n i n T a b l e 4.5. These results are more var ied and di f f icult to interpret than the results f r o m the P C P runs. O n one hand, there are only three runs i n w h i c h no N P breakthrough occurred, and these are a l l runs i n w h i c h no organoclay was present i n the cel ls . H o w e v e r , because these cel ls had l o w k, a very s m a l l v o l u m e o f permeant (60-86 m L ) f l o w e d through them. O n the other hand, 6 o f the 9 experimental runs had no N P i n the permeant u n t i l quite a h i g h v o l u m e (505-684 m L ) o f permeant had f l o w e d through the ce l l . T h e general trend seems to indicate that organoclay adsorbed N P better than bentonite i n this compacted c lay barrier material , but there are too many inconsistencies to make a definite conc lus ion . 84 Table 4.5: Breakthrough volumes for NP runs Sample Breakthrough volumes (mL) and comments C 1 3 N P detected at first reading (after 23 m L ) and throughout r u n (524 m L ) C 1 4 N P detected at first reading (after 102 m L ) and throughout r u n (745 m L ) . C 1 5 N P only detected i n trace amounts u n t i l 83 m L - [ N P ] variable unt i l end o f run (200 m L ) C 1 6 n/b - 60 m L C 1 7 N P detected at second reading (58 m L ) and present throughout run (432 m L ) C 1 8 n/b - 85 m L C 1 9 n/b - 86 m L E 1 3 N P breakthrough at 505 m L E 1 4 N P breakthrough at 687 m L E 1 5 N P breakthrough at 654 m L E 1 6 N P i n effluent i n s m a l l concentrations (0.03-0.13 mg/L) i n first 5 readings (up to 154 m L ) ; N P then disappeared f r o m effluent u n t i l breaking through at 493 m L E 1 7 N P i n effluent i n s m a l l concentrations (0.02-0.16 mg/L) in-first 5 readings (up to 151 m L ) ; N P then disappeared f r o m effluent u n t i l breaking through at 626 m L E 1 8 N P i n effluent i n s m a l l concentrations (0.06-0.52 m g / L ) i n first 6 readings (up to 138 m L ) ; N P then disappeared f r o m effluent u n t i l breaking through at 420 m L E 1 9 N P breakthrough at 655 m L E 2 0 N P breakthrough at 637 m L E 2 1 N P breakthrough at 565 m L 4.5.3 Toluene T L was not detected i n the effluent o f either the control or experimental runs. T h i s m a y have been due to v o l a t i l i z a t i o n o f T L i n the reservoir before entering the ce l l or i n the c o l l e c t i o n bottles w h i l e await ing co l lect ion. N o c o n c l u s i o n can be reached about whether the c lay barrier material containing organoclay adsorbed T L better than the c lay barrier material without organoclay. 4.5.4 Methyl Ethyl Ketone T h e results o f the effluent tests i n the M E K runs are presented i n table 4.6, w i t h the except ion o f runs E 2 5 and E 2 8 , w h i c h are s h o w n i n figure 4.28. T h e o n l y c o n c l u s i o n that can 85 be reached f r o m these h igh ly variable data is that organoclay d i d not adsorb M E K w e l l i n c lay barrier material . T h i s is not surprising, consider ing the very l o w adsorption achieved i n the batch adsorption tests (152 m g M E K / k g organoclay). Bentonite seems to have adsorbed M E K better, though m u c h l o w e r vo lumes f l o w e d through the control cel ls ( C 2 3 - C 2 5 ) . Table 4.6: Breakthrough volumes for M E K runs Sample Breakthrough volumes (mL) and comments C 2 3 n / b - 6 4 C 2 4 n / b - 2 1 7 C 2 5 n/b - 1 8 9 E 2 6 n / b - 7 2 3 E 2 7 M E K present i n effluent throughout r u n (263 m L ) f r o m 2.01 to 5.90 m g / L E 2 9 M E K present i n effluent throughout r u n (1533 m L ) f r o m 0.93 to 4.21 m g / L E 3 0 M E K present i n effluent at 112 and 147 m L (concentration = 1.32 and 1.22 m g / L respectively); otherwise, no M E K detected dur ing r u n (2082 m L ) 86 1.00E-05 1.00E-09 A 1 1 1 1 1 1 1 1 0. 200 400 600 800 1000 1200 1400 1600 Time (h) Figure 4.27: Hydraulic conductivity of runs E25, E26 and E28 3.50 0.0 500.0 1000.0 1500.0 2000.0 2500.0 3000.0 3500.0 Cumulative volume (mL) Figure 4.28: [MEK] for runs E25 and E28 87 C H A P T E R 5 C O N C L U S I O N S A N D R E C O M M E N D A T I O N S The objectives of this study were delineated in the Introduction (section 1.2). The first section of this chapter relates the results to these objectives and presents the conclusions reached. The second section specifies some of the contributions this research has made to the geo-environmental field, and the third section makes recommendations for future research related to the use of organoclays in clay barriers. 5.1 CONCLUSIONS The main finding of this research is that while organoclay has high adsorptivity for non-ionic organic contaminants, its presence has a negative impact on k o f clay barrier materials, and that this impact on k is often magnified by the presence of even dilute amounts of organic chemicals in the permeant liquid. The implication of these facts would seem to be that organoclay should not be included with the composition proportions used in the present study i f low k is desirable in a clay barrier (e.g., a landfill liner). The specific conclusions reached in this study are: I. Organoclay was produced by substituting H D T M A for 70% of the native cations on Na-bentonite using a relatively simple method that might be duplicated in an industrial setting. This organoclay performed comparably in batch adsorption tests to organoclays produced by other researchers who used more complex and difficult methods. II. In batch adsorption tests, the organoclay adsorbed all of the test chemicals (PCP, N P , T L , and M E K ) better than untreated bentonite. Adsorption of the test chemicals 88 o n the organoclay decreased i n the f o l l o w i n g order: m o l e c u l a r P C P > i o n i z e d P C P > N P > T L > M E K . A d s o r p t i o n o f M E K , the o n l y h y d r o p h i l i c c h e m i c a l i n the study, was extremely l o w for both organoclay and bentonite. W i t h the except ion o f i o n i z e d P C P , adsorption o f the test chemicals by organoclay increased w i t h increasing c h e m i c a l hydrophobic i ty . III. C l a y barrier material was successfully produced us ing var ious combinat ions o f sand, bentonite and organoclay. T h i s material was compacted at 1% above the o p t i m u m moisture content to dry densities v a r y i n g between 1.76 and 1.81 g/cm 3 , and was also used i n the k tests to discover i f the presence o f organoclay i n the material inf luenced k and i f the interaction between the test chemicals and the organoclay inf luenced k. I V . T h e presence o f organoclay i n c lay barrier material caused an increase i n k compared to c lay barrier material containing o n l y bentonite. T h i s p h e n o m e n o n was noted w i t h a l l permeants, whether or not the permeants contained test chemicals . I n k tests w i t h permeants that d i d not contain any organic chemicals , organoclay caused an average increase i n A: o f 4 t imes ( w i t h 0.01 M C a S 0 4 ) and 15 t imes ( w i t h 0.01 M C a C l 2 ) . I n the presence o f 10 m g / L P C P , organoclay caused an average increase i n k o f 14 t imes (wi th 0.01 M C a S 0 4 ) and 95 t imes ( w i t h 0.01 M C a C l 2 ) . I n the presence o f 10 m g / L N P , organoclay caused an average increase i n A: o f 9 t imes (a l l runs used 0.01 M C a C l 2 ) . In the presence o f 30 m g / L T L , organoclay caused an average increase i n A: o f 6 t imes (al l runs used 0.01 M C a C l 2 ) . I n the presence o f 10 m g / L M E K , organoclay caused an average increase i n A: o f 39 t imes (a l l runs used 0.01 M C a C l 2 ) . 89 V . T h e test chemicals , w i t h the possible exception o f P C P , had a considerable inf luence o n k o f the c lay barrier materials used. T h i s influence was more p r o n o u n c e d i n the c lay barrier materials w h i c h incorporated organoclay (experimental soi ls) . W h e n N P and T L were present i n the permeant, large and sudden increases i n k were observed i n experimental soi ls . These increases c o u l d mean that an c lay barrier w h i c h contains organoclay m a y not be useful w h e n permeated w i t h l i q u i d c o n t a i n i n g these chemicals . M E K appeared to cause a decrease i n k, especial ly i n exper imental soi ls . P C P caused a decrease i n k for a l l control soils and for some o f the exper imental soi ls . H o w e v e r , an increase i n k was observed for other experimental soi ls . V I . Ef f luent testing i n the P C P runs indicated that experimental soi ls adsorbed P C P m u c h more effectively than control soi ls . H o w e v e r , the adsorpt ion o f P C P b y experimental soi ls was m u c h l o w e r than might be expected based o n the results o f the batch adsorption tests. Problems w i t h var iabi l i ty and v o l a t i l i z a t i o n were encountered i n the other runs (i.e., w i t h N P , T L and M E K ) . Because o f these problems, definite conclusions c o u l d not be reached as to whether experimental soi ls adsorbed N P , T L or M E K better than control soi ls . 5.2 CONTRIBUTIONS T O T H E G E O - E N V I R O N M E N T A L F I E L D T h e results f r o m this study can be useful i n the design o f c lay barriers w h i c h incorporate organoclay , g i v i n g a better understanding o f the advantages and l imitat ions o f organoclay i n regard to its impact o n k and adsorptivity. Geo-environmenta l engineers w i l l have a better basis for m a k i n g decis ions about the o p t i m u m amount o f organoclay to inc lude i n c lay barriers and the thickness o f such barriers. 90 These results also enable engineers to make more i n f o r m e d decis ions regarding the amount o f cat ionic surfactant that should be injected into a subsoi l to create sorbent zones for the purpose o f preventing contaminant migrat ion . Better predict ions can also be made about h o w effectively such sorbent zones w i l l i m m o b i l i z e organic contaminants. Organoc lay was produced i n a re lat ively s imple and inexpensive manner that c o u l d be easi ly dupl icated i n an industr ia l setting. T h e adsorptivity o f this organoclay was c o m p a r e d to the adsorptivi ty o f organoclay produced by other researchers w i t h more c o m p l e x methods that w o u l d be d i f f icu l t and/or expensive to f o l l o w i n an industr ial setting. Organoclay 's impact o n k should a lways be taken into account w h e n it is incorporated into a c lay barrier. I f l o w k is necessary i n a c lay barrier, permeabi l i ty tests us ing the proposed permeant and c lay barrier material ( i n c l u d i n g organoclay) should be done beforehand to determine i f the barrier w i l l meet the requirements for l o w k w h i l e enhancing adsorptivi ty for H O C ' s . o S ince organoclay is u n l i k e l y to decrease k, permeabi l i ty tests m a y not be necessary for environmenta l applicat ions i n w h i c h h i g h k is desired, such as the creation o f a sorbent zone i n the subsoi l to contain a contaminant p l u m e . 5.3 RECOMMENDED FUTURE STUDIES It m a y be possible to enhance the adsorptivity o f a c lay barrier for H O C ' s u s i n g organoclay wi thout increasing A: b e y o n d the standard necessary for the barrier (e.g., 1 x 10"7 cm/s for most l a n d f i l l l iners). T h e f o l l o w i n g studies are recommended i n order to determine i f this is poss ible and pract ical : 1. Future research should consider the effect o n adsorptivi ty and k o f c lay barrier material w h e n various smaller proportions o f organoclay i n c lay barrier mater ia l are e m p l o y e d w i t h the same permeant. T h i s study used 4 . 0 % and 2 . 5 % organoclay i n the c lay barrier materia l ; future studies c o u l d investigate us ing , for example , 0 . 5 % , 1.0% and 1.5% organoclay. T h e permeant should inc lude di lute concentrations o f one or more H O C ' s . B y us ing the same permeant w i t h v a r y i n g proport ions o f organoclay, it c o u l d be determined at what percentage organoclay began to increase k, and i f incorporat ing organoclay i n the c lay barrier material at a percentage b e l o w this w o u l d s t i l l s igni f icant ly enhance the barrier's adsorptivi ty for the H O C ' s i n the permeant. 2. A n o t h e r study should examine the effect o f i so lat ing organoclay i n a separate layer or layers to reduce its effect o n k w h i l e cont inuing to enhance adsorptivi ty for H O C ' s . D u r i n g compact ion , a layer containing organoclay c o u l d be p laced between other layers w h i c h d i d not contain organoclay. L o w k w o u l d be ensured because o f the bentonite i n the layers w h i c h had no organoclay, w h i l e adsorptivi ty for H O C ' s i n the permeant w o u l d be enhanced by the layer w h i c h contained organoclay. There are several other issues encountered i n this research that are also r e c o m m e n d e d as subjects for further research: 1. I n this study, it was found that dilute concentrations o f N P and T L caused large and sudden increases i n k. Future studies should investigate the reasons for this phenomenon. T h e hypothesis that so i l shrinkage (caused by di lute concentrations o f these chemicals) l ed to these increases i n k should be tested i n systematic experiments. 2. It was observed i n this study that di lute concentrations o f M E K caused decreases i n k. Further research should investigate the reasons for this phenomenon. T h e 92 hypothesis that s o i l expansion (caused by dilute concentrations o f M E K ) l e d to these decreases i n k should be tested i n systematic experiments. Future studies should examine the reasons that organoclay does not adsorb P C P as w e l l i n c o l u m n leaching tests as it does i n batch adsorption tests. Y o n g et a l (1992) point out that these two types o f tests are very different and that the adsorpt ion characteristics determined i n one type o f test should not be confused w i t h the adsorption characteristics determined i n another. That said, batch adsorpt ion tests are m u c h more easi ly performed than c o l u m n leaching tests and it w o u l d be very useful to understand h o w the results f r o m batch adsorption tests c o u l d be used to estimate the adsorptivi ty o f a c lay barrier for H O C ' s . S o m e o f the reasons for the difference i n results between the two types o f tests m i g h t be: • L e s s p h y s i c a l contact between organoclay and H O C ' s i n the permeant d u r i n g the c o l u m n leaching tests due to preferential pathways through the leaching c e l l . • L e s s p h y s i c a l contact between organoclay and H O C ' s i n the permeant d u r i n g the c o l u m n leaching tests due to reduced surface exposure. T h i s reduct ion i n surface exposure is due to the fact that the organoclay is contained i n a s o i l m a t r i x w i t h a definite structure rather than being w i d e l y dispersed i n an agitated suspension as is the case i n batch adsorption tests ( Y o n g et a l , 1992). • Decreased contact t ime between organoclay and H O C ' s i n the permeant d u r i n g c o l u m n leaching tests. D u r i n g batch adsorption tests, organoclay is cont inuous ly exposed to H O C ' s i n an agitated so lut ion over a t ime o f 24 h . T h i s t i m e m a y be s igni f icant ly reduced i n a c o l u m n leaching test, especial ly i f k is h i g h . 93 • I n the c o l u m n leaching tests, di f fusive transport o f P C P to the organoclay m a y have been m u c h more important than was the case i n the batch adsorpt ion tests, where P C P was brought into contact w i t h organoclay largely by advective transport. S ince d i f fus ion is generally a s lower process than advect ion, this m a y have been a reason for the decreased adsorptivity i n the leaching c e l l . 4. Future research should examine the possible p r o b l e m o f cat ionic surfactant desorpt ion f r o m organoclay. It m a y be that higher concentrations o f inorganic or organic chemicals than were used i n this study w o u l d cause s ignif icant desorpt ion o f the surfactant. I f this were the case, the organoclay's capacity to adsorb H O C ' s f r o m the permeant w o u l d be impaired . Besides this, some o f the cat ionic surfactants are themselves t o x i c chemicals ; releasing them into the environment w o u l d be counter-product ive . 5. Further research should ascertain i f the results f r o m batch adsorption tests can be related to tests o f the effluent i n c o l u m n leaching tests w h i c h have di lute concentrations o f N P , T L and M E K i n the permeant. 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Z h a o , H , Jaynes, W . F . , and V a n c e , G . F . 1996. S o r p t i o n o f the ionizable organic c o m p o u n d , d i c a m b a (3 ,6-dichloro-2-methoxy benzoic acid) , by organo-clays. Chemosphere 33: 2 0 8 9 - 2 1 0 0 . 101 APPENDIX A: GRAIN SIZE ANALYSIS A l . Methods Sieve analysis was performed o n the sand, bentonite and organoclay us ing the m e t h o d o f L a m b e (1951). H y d r o m e t e r analysis was performed o n the bentonite and organoclay us ing an adaptation o f the method o f Bardet (1997). Details of hydrometer analysis A high-speed m i x e r was used tb stir approximately 700 m L o f d i s t i l l e d water. D u r i n g m i x i n g , 5.0 g o f s o d i u m hexametaphsophate and 30.0 g o f dry sample was added to the water. T h e sample was added s l o w l y to prevent c l u m p i n g . A f t e r m i x i n g the suspension for at least 10 m i n to f u l l y disperse the sample, the suspension was transferred to a 1.00 L sedimentat ion c y l i n d e r (~ 45 c m h i g h and 6 c m i n diameter). A d d i t i o n a l d i s t i l l e d water was used to rinse a l l o f the suspension into the cy l inder , and to fill the cy l inder to the 1.00 L mark. A second c y l i n d e r was filled w i t h d i s t i l l e d water to store and rinse the hydrometer. P r i o r to starting the test, the f o l l o w i n g measurements were taken. • T h e internal diameter o f the sedimentation cyl inder . • T h e v o l u m e o f the hydrometer bulb (measured by water displacement) . • T h e distances between the bulb center and graduation marks 0, 10, 2 0 , 30, 4 0 , 50, and 60 g/L. • T h e height o f the meniscus o n the hydrometer stem. U s i n g one hand to cover the open end o f the cy l inder , the sample was shaken for 30 s by cont inuous ly invert ing the cy l inder ups ide-down and back. T i m e was started at the point where shaking stopped and the cy l inder was set o n the table. A t 0 s, the hydrometer was inserted into the suspension. H y d r o m e t e r readings were taken at 15 s, 30 s, 1 m i n and 2 m i n without r e m o v i n g the hydrometer. Af ter the 2 m i n reading, the suspension was r e m i x e d and the test was restarted to check the readings. Once a consistent pair o f readings was obtained, the test was started again, and the hydrometer inserted just before the 2 m i n reading. A f t e r the 2 m i n reading, the hydrometer was r e m o v e d and subsequent readings were taken at 4, 8, 15 m i n . , etc. A f t e r each reading, the hydrometer was immediate ly removed. Readings cont inued u n t i l the elapsed t i m e was large enough to give the m i n i m u m particle diameter desired. I n a d d i t i o n to the hydrometer readings, the temperature o f the suspension was measured p e r i o d i c a l l y . A f t e r the final reading, the suspension was transferred to a tared container and dr ied for 24 h at 105° C to determine the exact dry weight o f the c lay. 102 Calculations T h e hydrometer data is s h o w n as a plot o f particle diameter D ( m m ) vs. percentage p f iner b y weight . T h e equation for particle diameter D (mm) is D - [ ( 3 0 n H r ) / ( 9 8 1 ) ( G s - l ) ( p w t ) ] 1 / 2 where t is the t ime (min) after the beg inning o f sedimentation, G s is the speci f ic gravity o f the particles (see A p p e n d i x B for specif ic gravity determination), p w is the density o f water (g/cm 3 ) at temperature T , n is the v iscos i ty o f water (g/cms) at temperature T , and H r is the corrected depth o f f a l l (cm). T h e corrected depth o f f a l l H r (cm) is H r = H + C m - ( V b / 2 A ) where H is the depth o f fa l l measured f r o m the meniscus to the center o f the bulb (cm), C m is the meniscus correct ion, V b is the v o l u m e o f the bulb (cm 3 ) , and A is the cross-sectional area o f the cy l inder . T h e percentage p by weight o f particles w i t h diameter smal ler than D is p = [ 6 2 . 2 6 / W 0 ] [ R - C d + m ] [ G s / ( G s - 1)] where W 0 is the oven-dried weight o f s o i l per l iter o f suspension (g/L), R is the suspension unit weight reading f r o m the hydrometer (g/L), C d is the def locculat ing agent correct ion (g/L), and m is the temperature correct ion (g/L). T h e def locculat ing agent correct ion C d (g/L) is c d = x d v s where X d is the amount o f s o d i u m hexametaphosphate added (g), and V s is the v o l u m e o f the suspension ( L ) . T h e temperature correct ion m (g/L) is m = 1000[0.99823 - p w - (0.000025 [T-20])] 103 A.2 R E S U L T S AND DISCUSSION T h e gra in size distributions for sand, bentonite and organoclay are l isted i n T a b l e A . 1 and s h o w n graphica l ly i n F i g u r e 4.1. It should be noted that a l l percentages for gra in sizes equal to or greater than 0.063 m m were obtained f r o m sieve analysis data, w h i l e a l l percentages for gra in sizes less than 0.063 m m were obtained f r o m hydrometer data. A s m i g h t be expected, most sand particles were found to be between 0.1 and 0.5 m m . T h i s large gra in size is consistent w i t h the sand's l o w cat ion exchange capacity (see A p p e n d i x G ) . Bentonite h a d a very different grain size distr ibut ion f r o m sand, w i t h 5 7 % o f the particles smal ler than 0.001 m m , the lower l i m i t o f the hydrometer test. T h i s is consistent w i t h bentonite's h i g h speci f ic surface and h i g h cat ion exchange capacity (see A p p e n d i c e s C and G ) . O r g a n o c l a y h a d an intermediate grain size d is tr ibut ion relative to the distr ibut ions o f sand and bentonite. H o w e v e r , it m a y be that grain size is overestimated i n the case o f organoclay , part icular ly as regards the hydrometer data, since organoclay tends to f locculate i n aqueous suspension. T h i s f locculat ion presumably occurs due to the h y d r o p h o b i c nature o f the organoclay; the h y d r o p h o b i c particles f locculate together to a v o i d the aqueous environment. T h o u g h the def locculat ing agent s o d i u m hexametaphosphate was used i n the hydrometer tests as ment ioned above, this agent m a y not have been as effective for organoclay as it was for bentonite. Table A . l : Grain size distribution of sand, bentonite and organoclay Sand Bentonite Organoclay Grain size % smaller Grain size % smaller Grain size % smaller (mm) than (mm) than (mm) than 0.417 99.7 0.833 99.9 0.833 98.1 0.297 90.3 0.420 99.5 0.420 86.5 0.250 75.1 0.297 99.2 0.297 76.0 0.149 33.9 0.250 98.9 0.250 70.7 0.125 17.5 0.149 98.0 0.149 59.8 0.104 8.5 0.125 96.7 0.125 53.7 0.074 2.4 0.104 94.9 0.104 48.7 0.074 94.3 0.074 41.4 0.063 92.5 0.063 32.9 0.023 91.2 0.042 31.7 0.016 89.4 0.030 15.6 0.012 89.4 0.025 8.7 0.009 85.8 0.022 7.8 0.006 81.5 0.011 5.9 0.003 76.8 0.004 5.5 0.002 75.0 0.001 67.8 0.001 62.1 0.001 57.0 104 APPENDIX B: SPECIFIC G R A V I T Y O F SOIL M A T E R I A L S B . l Methods Speci f ic gravity was determined for a l l the s o i l materials used i n the study: sand, bentonite, organoclay, control s o i l , and experimental s o i l . T h e m e t h o d used was adapted f r o m L a m b e (1951). T h e first step i n the procedure was to calibrate the pycnometer (a 500.0 m L glass v o l u m e t r i c f lask). It is necessary to obtain a ca l ibrat ion curve for the weight o f the pycnometer containing 500.0 m L o f de-aired, d i s t i l l e d water at v a r y i n g temperatures so that w h e n the speci f ic gravity test is done, compensat ion can be made for the di f fer ing density o f water at d i f fer ing temperatures. De-a ired water was produced by b o i l i n g d i s t i l l e d water for 15 m i n . Pycnometer weights were determined to 0.01 g at 22.7, 26 .8 , and 30.0° C and a ca l ibrat ion curve was obtained that y i e l d e d the f o l l o w i n g equation: W e i g h t o f pycnometer = (5219 - Temperature)/7.529 T h e next step was to de-air the s o i l materials w h i c h were to be used i n the speci f ic gravity test. T h i s was done by b o i l i n g the s o i l materials i n about 300 m L o f de-aired, d i s t i l l e d water for 15 m i n i n a 1000 m L E r l e n m e y e r flask. F o r both soi ls and the sand, approximate ly 50 g were used i n the test. F o r the untreated bentonite, 30 g were used since 50 g o f the bentonite s w e l l e d so m u c h that a gelatinous mass was created o n b o i l i n g . W h e n 20 g o f organoclay was b o i l e d , the m i x t u r e b o i l e d over out o f the E r l e n m e y e r flask, presumably due to the h i g h organic matter content o f the organoclay. Because o f this p r o b l e m , the organoclay was left i n de-aired, d i s t i l l e d water i n a v a c u u m overnight instead o f be ing bo i led . A f t e r b o i l i n g , the s o i l material/water suspension was left overnight i n the E r l e n m e y e r f lask to equil ibrate to r o o m temperature. A v a c u u m was appl ied to the E r l e n m e y e r f lask d u r i n g this p e r i o d to prevent re-aeration o f the s o i l material . T h e next day, the suspension was transferred to the 500.0 m L pycnometer. T h e E r l e n m e y e r f lask was washed several t imes w i t h de-aired, d i s t i l l e d water to ensure that a l l o f the s o i l material had been transferred to the pycnometer . T h e pycnometer was then made up to 500.0 m L w i t h d i s t i l l e d , de-aired water. A f t e r a l l o w i n g 2 hours for further equi l ibrat ion to r o o m temperature, the temperature o f the suspension was determined. T h e temperature was taken at several different levels i n the pycnometer to ensure that it was u n i f o r m throughout the suspension. T h e pycnometer v o l u m e was then adjusted to 500.0 m L i f necessary by adding or r e m o v i n g a s m a l l quantity o f water (1-3 m L ) to m a k e up for any density changes i n the water dur ing the last equi l ibrat ion per iod . T h e pycnometer containing the suspension was w e i g h e d to 0.01 g. T h e suspension was then transferred f r o m the pycnometer to a 1000 m L tared glass beaker. D i s t i l l e d water was used to w a s h out the pycnometer into the beaker and to ensure that a l l the s o i l mater ia l h a d been transferred. T h e beaker was then p laced i n a 105° C o v e n for d r y i n g . A f t e r d r y i n g for 48 h , a l l the water had evaporated, and the beaker was w e i g h e d to 0.01 g i n order to determine the exact dry weight o f the s o i l materia l . 105 Speci f ic gravity o f the soi ls was determined us ing the equation g i v e n b y L a m b e (1951): G s = ( W S G T ) / ( W S - W , + W 2 ) W h e r e : • G s = Spec i f i c gravity o f the so i l material (g/cm 3 ). • W s = D r y weight o f s o i l (g). • G T = Spec i f i c gravity o f d is t i l l ed water at the test temperature (g/cm 3 ). • W , = W e i g h t o f pycnometer containing so i l material/water suspension (g). • W 2 = W e i g h t o f pycnometer w i t h d is t i l l ed water at the test temperature (g) - f r o m the ca l ibrat ion curve. ,, B.2 Results and discussion T h e results o f the specif ic gravity tests are s h o w n i n Table B . l b e l o w . T h e speci f ic gravit ies o f sand, bentonite and control s o i l were 2.66, 2.64 and 2.65 g/cm 3 respect ively , w h i l e the speci f ic gravities o f organoclay and experimental s o i l were 2.23 and 2.62 g/cm 3 respectively. T h e m u c h l o w e r specif ic gravity o f the organoclay c o u l d be attributed to a change i n s o i l fabric such as that observed by B u d h u et al (1997), w h o compared organoclay to untreated bentonite u s i n g scanning electron microscopy . T h e y found that untreated bentonite had a dense plate- l ike fabric , w h i l e organoclay had a more open, granular fabric. T h e m u c h l o w e r specif ic gravity o f the organoclay compared to untreated bentonite accounts for the l o w e r specif ic gravity o f experimental s o i l compared to contro l s o i l (as the former contained 2 . 5 % organoclay, w h i l e the latter does not). Table B.l: Results of specific gravity tests Soil Material Test W, (g) W 2(g) W s(g) G-p G s Temperature (g/cm3) (g/cm3) (° Q S a n d 22.0 721.73 690.26 50.41 0.9978 2.66 Bentoni te 22.0 708.97 690.26 30.05 0.9978 2.64 C o n t r o l S o i l 22.4 722.19 690.21 51.27 0.9977 2.65 O r g a n o c l a y 22.2 701.19 690.24 19.83 0.9977 2.23 E x p e r i m e n t a l 22.3 721.08 690.22 49.78 0.9977 2.63 S o i l 106 APPENDIX C: SPECIFIC S U R F A C E O F B E N T O N I T E AND O R G A N O C L A Y C l : Methods Speci f ic surface was determined us ing an ethylene g l y c o l m o n o e t h y l ether ( E G M E ) m e t h o d adapted f r o m El tantawy and A r n o l d (1973). Samples o f air-dried bentonite and organoclay w e i g h i n g 1.1 g were p l a c e d i n tared a l u m i n u m f o i l dishes and dr ied at 60° C for 48 h . T h e dishes were w e i g h e d w i t h the c l a y before and after d r y i n g to determine moisture content and c lay dry weight. A p p r o x i m a t e l y 1.5 m L o f E G M E (Fisher) was added to each sample, w h i c h was then m a n u a l l y stirred to create a c lay-E G M E slurry. C l a y w h i c h adhered to the st irr ing r o d was returned to the s lurry b y d r i p p i n g E G M E o n the r o d . T h e samples were then placed i n a dessicator over anhydrous C a C l 2 (granular, 2 0 m e s h & finer, F isher) . A d i s h o f E G M E was also p laced i n the dessicator. T h e samples were left to equil ibrate for 30 m i n . T h e dessicator was then evacuated w i t h a v a c u u m p u m p . T h i s p u m p was r e m o v e d after 45 m i n , but the dessicator remained c losed and under v a c u u m u n t i l 24 h later. A f t e r 24 h , the v a c u u m was released f r o m the dessicator through a d r y i n g trap. T h e samples were weighed and returned to the dessicator, w h i c h was then evacuated again for 45 m i n and left for 24 h . T h i s process was repeated 8 more t imes u n t i l a total o f 240 h h a d passed and a stable weight had been achieved. I n theory, the difference between the dry weight o f the c lays and their weight after this t ime had passed represents a m o n o m o l e c u l a r layer o f E G M E c o v e r i n g the internal and external surfaces o f the clays. C.2: Results Resul ts are s h o w n i n Tables C l , C . 2 and C . 3 . T h e specif ic surface area i n m 2 /g is calculated us ing the equation p r o v i d e d b y Carter et a l (1986): A = W a / ( W S x 0.000286) W h e r e • A = specif ic surface i n (m 2/g). • W a = w e i g h t o f E G M E retained b y sample (g). • W s = weight o f dry c lay (g). • 0 .000286 = weight o f E G M E required to f o r m a m o n o m o l e c u l a r layer o n 1 m 2 o f surface. Table C l : Clay weight and moisture % of samples Sample Dish Tare (g) Before drying After drying Dry clay Moisture (g) (g) weight (g) (%) Bentoni te 1.5891 2.7140 2.6545 1.0654 5.58 Bentonite 1.5765 2.6947 2.6365 1.0600 5.49 O r g a n o c l a y 1.5738 2.7040 2.6695 1.0957 3.15 O r g a n o c l a y 1.5642 2.7171 2.6857 1.1215 2.80 107 Table C.2: Weight readings at various times during E G M E test Sample 24h 48h 72h 96h 120h 144h 168h 192h 216h 240h AH weights in grams B l 3.4520 2.8215 2.7978 2.7661 2.7593 2.7892 2.7911 2.7873 2.7939 2.7959 B 2 3.3923 2.8282 2.7774 2.7459 2.7422 2.7691 2.7723 2.7686 2.7738 2.7762 0 1 3.3542 2.8090 2.7736 2.7362 2.7310 2.7605 2.7647 2.7609 2.7689 2.7720 0 2 3.1234 2.8066 2.7931 2.7537 2.7484 2.7790 2.7836 2.7793 2.7870 2.7902 N o t e : B = Bentonite ; O = Organoclay Table C.3: Average specific surface of bentonite and organoclay Bentoni te 462.4 m 2 /g O r g a n o c l a y 326.4 m 2 /g N o t e ; T h e average specif ic surface was calculated f r o m the average weights o f bentonite and organoclay at 240 h . 108 APPENDIX D: O P T I M U M M O I S T U R E C O N T E N T AND M A X I M U M D R Y DENSITY O F SOILS O p t i m u m moisture contents as determined by A S T M D 6 8 9 - 9 1 ( A m e r i c a n Society for Test ing and M a t e r i a l s , 1992) are presented i n Table D . l be low. Table D . l : Optimum moisture contents and maximum dry densities of control and experimental soils Soil Optimum moisture Maximum dry density (g/cm3) content (%) S o i l # 1 13.0 1.86 S o i l # 2 14.0 1.82 S o i l # 3 13.5 1.84 S o i l # 4 14.0 1.78 N o t e : S o i l # 1: 8 8 . 0 % sand, 1 2 . 0 % untreated bentonite S o i l # 2: 9 2 . 5 % sand, 7 . 5 % untreated bentonite S o i l # 3: 8 8 . 0 % sand, 8 . 0 % untreated bentonite, 4 . 0 % organoclay S o i l # 4: 92.5%) sand, 5 . 0 % untreated bentonite, 2 . 5 % organoclay T h e c o m p a c t i o n curves for these soi ls are s h o w n i n figures D . l , D . 2 , D . 3 , and D . 4 for soi ls #1, 2, 3, and 4 respectively. I n general, it was observed that: 1. R e d u c i n g the total amount o f c lay (i.e., bentonite plus organoclay) f r o m 1 2 % to 7 . 5 % increased o p t i m u m moisture content and reduced m a x i m u m dry density (so i l # 1 vs. s o i l # 2, s o i l # 3 vs. s o i l # 4). 2. I n c l u d i n g organoclay i n the s o i l caused an decrease i n m a x i m u m dry density ( so i l # 1 vs . s o i l # 3, s o i l # 2 vs. s o i l # 4). 109 1.90 -, 8.00 10.00 12.00 14.00 16.00 18.00 20.00 Moisture content (%) Figure D.1: Compaction curve for soil # 1 1.82 6.00 7.00 8.00 9.00- 10.00 11.00 12.00 13.00 14.00 15.00 16.00 Moisture content (%) Figure D.2: Compaction curve for soil # 2 110 1.84 10.00 10.50 11.00 11.50 12.00 12.50 13.00 13.50 14.00 14.50 Moisture content (%) Figure D.3: Compaction curve for soil # 3 1.78 ., 13.70 13.80 13.90 14.00 14.10 14.20 14.30 14.40 14.50 14.60 14.70 Moisture content (%) Figure D.4: Compaction curve for soil #4 111 APPENDIX E : C A R B O N A N A L Y S E S O F O R G A N O C L A Y AND B E N T O N I T E E . l : Methods T o determine i f the H D T M A had i n fact been adsorbed o n the cat ion exchange sites, 1 g o f oven-dry organoclay was w e i g h e d to four d e c i m a l places and c o m b i n e d w i t h 2 0 m L d i s t i l l e d water i n a 50 m L glass centrifuge tube. T h i s mixture was shaken for 15 m i n o n a w r i s t shaker, centrifuged at 2 0 0 0 r p m for 15 m i n , and the supernatant poured into a 100.0 m L v o l u m e t r i c flask. 20 m L o f d i s t i l l e d water was then added to the organoclay and the process was repeated. T h i s was done a total o f 4 t imes to give a total supernatant v o l u m e o f 80 m L . T h i s v o l u m e was made up to 100.0 m L i n the vo lumetr ic flask and then tested for organic carbon content o n a T C - 5 0 0 S h i m a d z u Organic C a r b o n A n a l y z e r . T h e bentonite was ashed for 2 h at 550° C i n a muff le furnace to establish its organic matter content, w h i c h was then used to estimate organic carbon content. E.2: Results and discussion Bentonite T a b l e E . 1 shows the results for organic carbon content i n bentonite. These data g ive an average organic matter content i n bentonite o f 2 .21%. H o w e v e r , not a l l o f this organic matter is organic carbon - it is generally assumed that the ratio o f organic matter:organic carbon is 1.7:1.0 ( B r a d y , 1990). Therefore, an average o f 1 .30% o f the weight o f this bentonite is made up o f organic carbon. Table E . l : Organic carbon content of bentonite Sample Crucible tare With oven-dry With ashed Organic Organic carbon (g) bentonite (g) bentonite (g) matter % % 1 10.3760 11.4686 11.4445 2.2057 1.2975 2 10.6326 11.4698 11.4515 2.1859 1.2858 3 9.9862 10.7386 10.7223 2.1664 1.2744 4 10.5465 11.4280 11.4082 2.2462 1.3213 5 10.5698 11.4566 11.4367 2.2440 1.3200 Organoclay T h e ca lcu la t ion o f the organic carbon content o f the organoclay was done i n the f o l l o w i n g manner: 1. A s s u m e that a l l exchange sites o n the bentonite are o r i g i n a l l y o c c u p i e d b y s o d i u m (Na) and that 7 0 % o f the N a is replaced b y H D T M A . 2. Further assume that excess N a and B r o m i n e (Br) f r o m the b r o m i d e salt o f H D T M A ( H D T M A - B r ) are washed away i n the repeated washings o f the organoclay. 3. T h e o r i g i n a l dry weight o f bentonite used i n preparing organoclay was 100.0 g. 4. T h e weight o f H D T M A - B r added to this c lay was 15.05 g or 0.041 m o l . 112 5. There are 19 carbon atoms i n the H D T M A - B r molecule w i t h a total m o l e c u l a r weight o f 228.19 g/mol. Since the molecular weight o f H D T M A - B r is 364.46 g/mol, carbon makes up 6 2 . 6 % o f the molecular weight or 9.42 g o f the 15.05 g added. 6. S ince H D T M A replaces N a o n the c lay, the weight o f the N a r e m o v e d must be subtracted f r o m the c lay weight. Since 0.041 m o i H D T M A - B r was added, 0.041 m o i or 0.95 g N a must have been removed. 7. T h e m o l e c u l a r weight o f H D T M A (wi th B r removed) is 284.56 g/mol; 0.041 m o i or 11.67 g was added to the bentonite. 8. T h e f ina l dry weight o f organoclay prepared f r o m 100.0 g o f bentonite w o u l d be: 100.0 g - 0.95 g + 11.67 g = 110.7 g. 9. T h e total carbon i n this 110.7 g is 1.30 g (or ig inal organic carbon f r o m the bentonite) + 9.42 g (carbon added w i t h the H D T M A ) = 10.72 g. 10. T h e organic carbon content o f the organoclay is 10.72 g/110.7 g = 9.7%. T a b l e E . 2 shows the results o f organic carbon analyses o f the supernatant der ived f r o m the organoclay as described above. The average amount o f organic carbon r e m o v e d f r o m the organoclay was 0 . 2 0 % . I f it is assumed that the native organic carbon was not r e m o v e d at a l l (i.e. a l l the carbon r e m o v a l was f r o m the H D T M A - C i n the organoclay) , there is an average r e m o v a l o f 0 . 2 3 % o f the H D T M A - C . Therefore at least 9 9 . 7 7 % o f the H D T M A was retained o n the organoclay through the m u l t i p l e washings. Table E.2: Organic carbon removed by repeated washing of organoclay Sample # % Organic C removed % H D T M A - C removed if all C came from H D T M A 1 0.22 0.24 2 0.18 0.19 3 0.20 0.22 4 0.21 0.24 5 0.21 0.23 113 APPENDIX F: SOIL AND E F F L U E N T P H M E A S U R E M E N T S F . l Methods T h e p H o f the three materials used (sand, untreated bentonite and organoclay) was measured i n d i s t i l l e d water and i n 0.01 M C a C l 2 w i t h an adaptation o f the m e t h o d used b y M c L e a n (1982). F o r p H measurement i n water, a s o i l material:water ratio o f 1:1 is general ly used. F o r measurement o f p H i n 0.01 M C a C l 2 , a ratio o f 1:2 is the n o r m . These ratios were used i n measur ing the sand's p H . H o w e v e r , it was not possible to observe these ratios w h e n measur ing the p H o f untreated bentonite and organoclay. T h e ratios were changed to 1:10 i n both cases to a l l o w thorough wett ing o f the so i l materials and to a l l o w for settlement. T a b l e F . l gives a s u m m a r y o f the s o i l materials and l i q u i d vo lumes used for the p H measurements. Table F . l : Soil materials and liquid volumes used for pH measurements Material Liquid added Mass of soil Volume of Soil materiahliquid material (g) liquid added (mL) ratio (w:w) Bentoni te Water 2.0 20.0 1:10 Bentoni te 0.01 M C a C l 2 2.0 20.0 1:10 O r g a n o c l a y Water 2.0 20.0 1:10 O r g a n o c l a y 0.01 M C a C l 2 2.0 20.0 1:10 Sand Water 5.0 5.0 1:1 S a n d 0.01 M C a C l 2 5.0 10.0 1:2 T h e s o i l materials were p laced i n 100 m L plastic beakers, after w h i c h the l i q u i d was added and the suspensions were manual ly stirred. T h e suspensions were m a n u a l l y stirred every 5 m i n for the next 30 m i n , and then a l l o w e d to settle for 30 m i n . A B e c k m a n cp44 p H meter and an O a k t o n e p o x y body p H electrode were used to measure the p H o f the part ia l ly settled suspensions. F.2 Results and discussion T h e results o f the s o i l p H testing are s h o w n i n Table F . 2 . In the present study, these results are most relevant to the p H readings done o n the effluent i n the k tests (see A p p e n d i x J) . T h e pattern o f p H change over t ime i n the effluent is consistent w i t h the p H o f the s o i l materials i n 0.01 M C a C l 2 , w h i c h is the most comparable since a l l effluent tests were i n 0.01 M C a C l 2 or 0.01 M C a S 0 4 . F o r example, i n R u n C 4 , f l o w and k were very l o w (123 m L over 2017 h). Because o f this, the so i l materials had a large influence o n the p H o f the effluent, w h i c h started out at 8.10 and o n l y dropped to 7.95 by the end o f the run. T h i s pattern was s i m i l a r i n most runs w h i c h had l o w e r k and f low. 114 C o m p a r e these results to R u n E 4 , w h i c h had m u c h higher k and f l o w (2282 m L over 1341 h). I n this r u n , p H after 22 m L o f f l o w (the first reading) was 7.71, and as more permeant f l o w e d through the leaching c e l l , p H gradual ly decreased to between 7.50 and 7.60, where it stabi l ized. T h i s pattern was s i m i l a r i n most runs w h i c h had higher k and f l o w . Table F.2: Measured pH of soil materials Liquid Sand Bentonite Organoclay D i s t i l l e d Water 4.72 8.38 7.94 0.01 M C a C l 2 7.67 7.61 7.69 115 APPENDIX G : C A T I O N E X C H A N G E C A P A C I T Y O F B E N T O N I T E A N D SAND G . l : Methods T h e cat ion exchange capacity ( C E C ) o f the bentonite and the sand were determined w i t h a s o d i u m acetate replacement method adapted from Rhoades (1982). Bentonite and sand were oven-dr ied at 105° C before testing began. A p p r o x i m a t e l y 1 g o f bentonite and 5 g o f sand was used for C E C determination. Weights were determined to four d e c i m a l places o n an analyt ica l balance. T h e samples were placed i n 50 m L plastic centrifuge tubes. 2 0 m L o f 1 M s o d i u m acetate ( N a O A c ) was added to the samples, w h i c h were then shaken o n a mechanica l wrist-shaker for 15 m i n and left overnight. T h e samples were centrifuged at 3500 r p m for 15 m i n , the supernatant poured o f f and discarded, and another 20 m L o f N a O A c added, f o l l o w e d by another 15 m i n shaking. T h i s process was repeated t w i c e m o r e w i t h N a O A c . Af ter this process o f saturating the samples w i t h N a + , it was presumed that N a h a d o c c u p i e d v i r t u a l l y a l l the cat ion exchange sites i n the samples. T h e c lay used was a s o d i u m bentonite w h i c h w o u l d have had most o f its cat ion exchange sites already o c c u p i e d b y s o d i u m ions. A f t e r centr i fuging and discarding the supernatant f r o m the last N a O A c w a s h i n g , 20 m L o f 2-propanol was added to the samples, w h i c h were shaken for 15 m i n , then centrifuged at 3500 r p m for 15 m i n . T h e supernatant a lcohol was poured o f f and discarded. T h i s process was repeated three t imes. T h e purpose o f w a s h i n g w i t h a l c o h o l was to remove any N a O A c r e m a i n i n g i n the s o i l pores without r e m o v i n g the N a + o n the exchange sites. A m m o n i u m acetate ( N H 4 O A c ) at 1 M concentration was then used to displace the N a + adsorbed to the exchange sites. Once again, four 20 m L aliquots were used, f o l l o w e d b y shaking and centri fuging. T h e samples were i m m e r s e d i n the last a l iquot overnight, w i t h a f ina l shaking and centr i fuging done the next m o r n i n g . T h e supernatant f r o m a l l four al iquots was poured o f f into 100.0 m L vo lumetr ic flasks, w h i c h were then made up to v o l u m e w i t h 1 M N H 4 O A c . Resuspens ion o f the c lay pr ior to shaking was done b y hand for the N a O A c washings , but a vortex shaker h a d to be used for both the i s o p r o p y l a lcohol and N H 4 O A c washings , since centr i f i igat ion produced a s o l i d p l u g o f c lay i n the bot tom o f the centrifuge tube that c o u l d not be resuspended b y either hand or mechanica l wrist shaking. T h e supernatant f r o m the c lay samples underwent a 1:25 d i l u t i o n by pipett ing 4 m L o f s o l u t i o n f r o m the 100.0 m L vo lumetr ic flask into another 100.0 m L v o l u m e t r i c f lask, w h i c h was then brought up to v o l u m e w i t h 1 M N H 4 O A c . T h e supernatant f r o m the sand samples was not d i luted. A l l samples were analyzed for N a o n a T h e r m o Jarrel l A s h V i d e o 22 A t o m i c A b s o r p t i o n / A t o m i c E m i s s i o n Spectrophotometer ( A A S ) . Standards o f 0, 1, 2, 4, 7 and 10 m g N a / L were prepared us ing N a C l d isso lved into 1 M N H 4 O A c . A l l standards and samples were a c i d i f i e d b y the addi t ion o f 0.5 m L concentrated H N 0 3 . 5.0 m L o f 4 0 , 0 0 0 m g / L L a as L a C l 3 was added to a l l standards and samples to e l iminate interferences w i t h N a determinat ion o n the A A S . 116 G.2: Results and discussion C E C i n centimoles o f posi t ive charge per k i l o g r a m (cmol/kg) was calculated f r o m the f o l l o w i n g equation: C E C (cmol/kg) = a m g x O . l L x & x 1_ x 1 g x 1000 g x 1 m o l x 100 c m o l L e g 1000 m g 1 k g 22.99 g m o l W h e r e • a - A A S determination o f m g N a / L • b = d i l u t i o n factor • c = sample weight There were 10 samples o f bentonite (samples 1-10) and t w o sand samples (11 and 12). T h e results o f C E C determination are presented i n the Table G . 1. I n the ca lcu la t ion o f the m e a n and 9 5 % confidence l i m i t s for the C E C o f the bentonite, sample 8 was not considered. T h i s was because about 1/3 o f the first N H 4 O A c w a s h i n g was s p i l l e d and lost. T h i s w o u l d constitute a major loss o f N a + . W i t h sample 3, about 2 m L was extracted f r o m the approximate ly 80 m L taken f r o m the four N H 4 O A c washings before d i l u t i o n to 100.0 m L . W h e n this mistake was real ized, the sample was made up to 100.0 m L and the procedure continued. T h i s w o u l d m e a n about 1/40 o f the N a + i n this sample was lost, and the f ina l result c o u l d be adjusted accordingly . T h e adjustment value is g i v e n i n i tal ics . T h e m e a n and 9 5 % confidence l i m i t s levels were calculated both e x c l u d i n g and i n c l u d i n g this adjusted result for sample 3. I f sample 3 is exc luded, the m e a n and confidence l i m i t s are 59.0 ± 0.8 cmol/kg . I f the adjusted result for sample 3 is i n c l u d e d , the m e a n and confidence l i m i t s are 58.8 ± 0.8 cmol/kg . It was decided to use 59.0 c m o l / k g as the C E C o f bentonite. T h e average C E C o f the sand was 0.174 cmol/kg, rounded o f f to 0.2 c m o l / k g for c o m p a r i s o n to the bentonite. Table G.l: Cation exchange capacity of bentonite and sand Sample [Na] a Dilution Factor Sample Weight c CEC Number (mg/L) b (g) (cmol/kg) 1 5.46 25 1.0003 59.36 2 5.58 25 1.0076 60.22 3 5.17 25 1.0055 55.91 (57.34) 4 5.50 25 1.0036 59.59 5 5.35 25 1.0002 58.17 6 5.47 25 1.0059 59.13 7 5.34 25 1.0019 57.96 8 4.79 25 1.0072 51.72 9 5.51 25 1.0040 59.68 10 5.33 25 1.0004 57.94 11 1.95 1 5.0042 0.169 12 2.06 1 5.0012 0.179 117 APPENDIX H : D E T A I L E D GAS C H R O M A T O G R A P H CONDITIONS Pentachlorophenol Effluent Analysis T y p e o f G C : H P 6980 C a r r i e r gas: H e Injector m o d e : splitless Solvent: H e x a n e C o l u m n • T y p e : H P - 5 M S ; 5 % P h e n y l M e t h y l S i loxane • D i m e n s i o n s : 30.0 m X 250 u,m X 0.25 u m ( f i l m thickness). • F l o w : 0.9 m L / m i n • Pressure: 66.2 k P a Inject ion v o l u m e : 1.0 u L O v e n • In i t ia l temperature: 40° C • M a x i m u m temperature: 320° C • Rate o f increase i n temperature: 20° C / m i n Detector: • I o n Source temperature: 230° C • Quadropole temperature: 150 ° C • Interface temperature: 280° C Inlet: • Temperature: 2 7 5 ° C • Pressure: 66.2 k P a • F l o w : 53.6 m L / m i n R u n T i m e : 12.0 m i n M i n i m u m peak w i d t h : 0.01 m i n Naphthalene Effluent Analysis T y p e o f G C : H P 6980 C a r r i e r gas: H e Injector mode: splitless Solvent: M e t h y l e n e chlor ide C o l u m n • T y p e : H P - 5 M S ; 5 % P h e n y l M e t h y l S i loxane • D i m e n s i o n s : 30.0 m X 250 p m X 0.25 urn ( f i l m thickness). • F l o w : 0.9 m L / m i n • Pressure: 43.4 k P a Inject ion v o l u m e : 1.0 u L O v e n • In i t ia l temperature: 40° C • M a x i m u m temperature: 320° C • Rate o f increase i n temperature: 20° C / m i n Detector: • I o n Source temperature: 230° C • Quadropole temperature: 150 0 C • Interface temperature: 280° C Inlet: • Temperature: 2 7 5 ° C • Pressure: 43.4 k P a • F l o w : 53.7 m L / m i n R u n T i m e : 10.0 m i n M i n i m u m peak w i d t h : 0.01 m i n Toluene Effluent Analysis T y p e o f G C : H P 6980 C a r r i e r gas: H e Injector m o d e : splitless Solvent: M e t h y l e n e chlor ide C o l u m n • T y p e : H P - 5 M S ; 5 % P h e n y l M e t h y l S i loxane • D i m e n s i o n s : 30.0 m X 250 urn X 0.25 urn ( f i l m thickness) . • F l o w : 0.9 m L / m i n • Pressure: 43.4 k P a Inject ion v o l u m e : 1.0 u L O v e n • In i t ia l temperature: 40° C • M a x i m u m temperature: 320° C • Rate o f increase i n temperature: 20° C / m i n Detector: • I o n Source temperature: 230° C • Quadropole temperature: 150 ° C • Interface temperature: 280° C Inlet: • Temperature: 200° C • Pressure: 43.4 k P a • F l o w : 63.7 m L / m i n R u n T i m e : 10.0 m i n M i n i m u m peak w i d t h : 0.01 m i n 119 Methyl Ethyl Ketone Effluent Analysis T y p e o f G C : H P 5 8 8 0 A Solvent: 0.01 M C a C l 2 i n d is t i l l ed water Injector m o d e : splitless C o l u m n : 6' stainless steel c o l u m n packed w i t h C a r b o w a x 20 M 7 . 2 5 % o n C h r o m W A W D M C S Inject ion v o l u m e : 1.0 u L O v e n temperature: 60° C Detector temperature: 200° C Injector temperature: 150° C M i n i m u m peak w i d t h : 0.08 m i n R u n T i m e : 3.0 m i n T h e carrier gas was H e , w i t h a f l o w rate o f 20 m L / m i n . 120 APPENDIX I: C A L C U L A T I O N O F ORGANIC C H E M I C A L C O N C E N T R A T I O N IN D I L U T E D S A M P L E S I f a sample f r o m one o f the effluent tests was less than 5.0 m L , it had to have enough 0.01 M C a S 0 4 or 0.01 M C a C l 2 added to it to br ing it up to 5.0 m L . T h e reason for this was that a l l the other samples and the standards used for testing o n the gas chromatograph ( G C ) were 5.0 m L . U s i n g different sample vo lumes w o u l d have affected the analysis. It was therefore dec ided to di lute the samples and then a l l o w for the d i l u t i o n i n the f inal results. T h e equation used for this was: R e a l [test chemical ] = [test chemical] x (5.0/sample v o l u m e ) F o r example , i f the sample v o l u m e was 1.4 m L i n one o f the pentachlorophenol ( P C P ) runs, the sample was brought up to 5.0 m L w i t h 0.01 M C a S 0 4 or 0.01 M C a C l 2 and stored i n a 5.0 m L glass bottle w i t h a P T F E - l i n e d l i d . I f the G C analysis y i e l d e d a [ P C P ] o f 1 m g / L , the actual [ P C P ] w o u l d be: R e a l [ P C P ] = (1 m g / L ) x (5.0 mL/1 .4 m L ) = 3.6 m g / L 121 APPENDIX J : D E T A I L E D H Y D R A U L I C CONDUCTIVITY, E F F L U E N T P H AND E F F L U E N T C O N C E N T R A T I O N T A B L E S Hydraulic conductivity and pH data for Run Cl Elapsed Flow (mL) Cumulative Head k (cm/s) pH Time (h) Flow (mL) 41.5 30.0 30.0 41.5 2.39E-07 7.52 67.5 17.0 47.0 41.5 2.16E-07 7.60 93.0 3.5 50.5 41.5 4.53E-08 8.21 115.5 2.5 53.0 41.5 3.67E-08 138.5 2.0 55.0 41.5 2.87E-08 163.5 2.0 57.0 41.5 2.64E-08 188.0 1.5 58.5 41.5 2.02E-08 211.0 1.5 60.0 41.5 2.15E-08 235.0 2.0 62.0 41.5 2.75E-08 7.85 259.0 2.0 64.0 41.5 2.75E-08 285.0 1.5 65.5 41.5 1.9E-08 304.0 1.5 67.0 41.5 2.61E-08 329.0 6.0 73.0 96.9 3.39E-08 7.92 Hydraulic Conductivity and pH data for Run C2 Elapsed Flow (mL) Cumulative Head k (cm/s) pH Time (h) Flow (mL) 30.0 2.0 2.0 39.4 2.32E-08 70.0 3.0 5.0 39.4 2.61E-08 99.0 2.0 7.0 39.4 2.4E-08 121.0 1.0 8.0 39.4 1.58E-08 8.41 166.5 4.0 12.0 39.4 3.05E-08 243.0 9.0 21.0 39.4 4.09E-08 265.0 2.5 23.5 39.4 3.95E-08 291.0 2.0 25.5 39.4 2.67E-08 308.5 2.0 27.5 39.4 3.97E-08 8.35 Hydraulic conductivity and pH data for Run C3 Elapsed Flow (mL) Cumulative Head k (cm/s) pH Time (h) Flow (mL) 30.0 9.0 9.0 39.4 1.04E-07 8.32 70.0 24.0 33.0 39.4 2.08E-07 8.35 99.0 21.0 54.0 39.4 2.52E-07 7.99 121.0 11.0 65.0 39.4 1.74E-07 7.65 166.5 35.5 100.5 39.4 2.71E-07 7.71 243.0 50.0 150.5 39.4 2.27E-07 7.63 265.0 9.5 160.0 39.4 1.5E-07 7.50 291.0 9.5 169.5 39.4 1.27E-07 7.55 308.5 7.0 176.5 39.4 1.39E-07 7.56 Hydraulic conductivity and pH data for Run C4 Elapsed Flow (mL) Cumulative Head k (cm/s) pH Time (h) Flow (mL) 69.0 4.7 4.7 67.8 1.38E-08 97.0 2.0 6.7 67.8 1.44E-08 141.0 3.9 10.6 67.8 1.79E-08 192.0 3.9 14.5 67.8 1.55E-08 8.10 242.0 3.3 17.8 67.8 1.33E-08 269.0 1.9 19.7 67.8 1.42E-08 298.0 2.1 21.8 69.2 1.43E-08 340.0 2.7 24.5 69.2 1.27E-08 367.0 1.9 26.4 69.2 1.39E-08 8.18 412.0 3.0 29.4 69.2 1.32E-08 437.0 1.5 30.9 69.2 1.19E-08 458.0 1.3 32.2 67.8 1.25E-08 509.0 3.2 35.4 67.8 1.27E-08 580.0 5.0 40.4 67.8 1.42E-08 606.0 1.6 42.0 67.8 1.24E-08 8.09 636.0 1.9 43.9 67.8 1.28E-08 676.0 2.6 46.5 67.8 1.31E-08 749.0 5.4 51.9 67.8 1.49E-08 772.0 1.9 53.8 67.8 1.67E-08 796.0 1.7 55.5 67.8 1.43E-08 8.20 842.0 3.4 58.9 67.8 1.49E-08 919.0 4.9 63.8 67.8 1.29E-08 942,0 1.5 65.3 67.8 1.32E-08 992.0 2.8 68.1 67.8 1.13E-08 1011.0 1.3 69.4 67.8 1.38E-08 1082.0 3.8 73.2 67.8 1.08E-08 8.04 1133.0 2.7 75.9 67.8 1.07E-08 1181.0 2.4 78.3 67.8 1.01E-08 1248.0 3.5 81.8 67.8 1.06E-08 1281.0 1.6 83.4 67.8 9.8E-09 1349.0 3.3 86.7 67.8 9.81E-09 1424.0 3.9 90.6 67.8 1.05E-08 7.99 1477.0 2.9 93.5 67.8 1.11E-08 1516.0 1.8 95.3 67.8 9.33E-09 1587.0 3.5 98.8 67.8 9.96E-09 1682.0 4.9 103.7 67.8 1.04E-08 1757.0 4.1 107.8 67.8 1.1E-08 1830.0 4.1 111.9 67.8 1.13E-08 1927.0 5.8 117.7 67.8 1.21E-08 7.95 2017.0 5.0 122.7 67.8 1.12E-08 Hydraulic conductivity and pH data for Run C5 Elapsed Flow (mL) Cumulative Head k (cm/s) pH Time (h) Flow (mL) 69.0 47.6 47.6 67.8 1.38E-08 7.97 97.0 14.3 61.9 67.8 1.44E-08 7.96 141.0 22.1 84.0 67.8 1.79E-08 7.97 192.0 23.8 107.8 67.8 1.55E-08 7.96 242.0 20.9 128.7 67.8 1.33E-08 7.92 269.0 12.5 141.2 67.8 1.42E-08 7.51 298.0 13.6 154.8 69.2 1.43E-08 7.63 340.0 19.6 174.4 69.2 1.27E-08 7.71 367.0 13.5 187.9 69.2 1.39E-08 7.45 412.0 20.6 208.5 69.2 1.32E-08 7.47 437.0 9.9 218.4 69.2 1.19E-08 7.46 458.0 9.5 227.9 67.8 1.25E-08 7.38 509.0 24.5 252.4 67.8 1.27E-08 7.35 580.0 40.2 292.6 67.8 1.42E-08 7.39 606.0 13.8 306.4 67.8 1.24E-08 7.40 636.0 15.6 322.0 67.8 1.28E-08 7.30 676.0 20.7 342.7 67.8 1.31E-08 7.29 749.0 46.7 389.4 67.8 1.49E-08 7.25 772.0 16.1 405.5 67.8 1.67E-08 7.20 796.0 16.2 421.7 67.8 1.43E-08 7.29 842.0 28.1 449.8 67.8 1.49E-08 7.35 919.0 44.3 494.1 67.8 1.29E-08 7.24 942.0 13.1 507.2 67.8 1.32E-08 7.27 992.0 26.0 533.2 67.8 1.13E-08 7.19 1011.0 11.8 545.0 67.8 1.38E-08 7.18 1082.0 38.2 583.2 67.8 1.08E-08 7.15 1133.0 23.1 606.3 67.8 1.07E-08 7.22 1181.0 30.2 636.5 67.8 1.01E-08 7.22 1248.0 49.9 686.4 67.8 1.06E-08 7.26 1281.0 22.1 708.5 67.8 9.8E-09 7.27 1349.0 46.9 755.4 67.8 9.81E-09 7.19 1424.0 52.9 808.3 67.8 1.05E-08 7.20 1477.0 34.9 843.2 67.8 1.11E-08 7.18 1516.0 23.3 866.5 67.8 9.33E-09 7.21 1587.0 54.8 921.3 67.8 9.96E-09 7.27 1682.0 78.0 999.3 67.8 1.04E-08 7.18 1757.0 71.1 1070.4 67.8 1.1E-08 7.19 1830.0 76.1 1146.5 67.8 1.13E-08 7.20 1927.0 87.2 1233.7 67.8 1.21E-08 7.21 2017.0 75.4 1309.1 67.8 1.12E-08 7.19 Hydraulic conductivity and pH data for Run C6 Elapsed Flow (mL) Cumulative Head k (cm/s) pH Time (h) Flow (mL) 69.0 3.1 3.1 67.8 1.38E-08 97.0 1.6 4.7 67.8 1.44E-08 141.0 2.2 6.9 67.8 1.79E-08 192.0 2.4 9.3 67.8 1.55E-08 242.0 2.3 11.6 67.8 1.33E-08 8.39 269.0 1.4 13.0 67.8 1.42E-08 298.0 1.5 14.5 69.2 1.43E-08 340.0 1.9 16.4 69.2 1.27E-08 367.0 1.3 17.7 69.2 1.39E-08 412.0 2.3 20.0 69.2 1.32E-08 8.35 437.0 1.2 21.2 69.2 1.19E-08 458.0 0.9 22.1 67.8 1.25E-08 509.0 2.4 24.5 67.8 1.27E-08 580.0 3.3 27.8 67.8 1.42E-08 606.0 1.2 29.0 67.8 1.24E-08 636.0 1.4 30.4 67.8 1.28E-08 8.34 676.0 1.9 32.3 67.8 1.31E-08 749.0 3.4 35.7 67.8 1.49E-08 772.0 1.1 36.8 67.8 1.67E-08 796.0 1.1 37.9 67.8 1.43E-08 842.0 2.2 40.1 67.8 1.49E-08 919.0 3.4 43.5 67.8 1.29E-08 942.0 1.0 44.5 67.8 1.32E-08 8.21 992.0 2.1 46.6 67.8 1.13E-08 1011.0 0.9 47.5 67.8 1.38E-08 1082.0 3.0 50.5 67.8 1.08E-08 1133.0 2.3 52.8 67.8 1.07E-08 1181.0 2.0 54.8 67.8 1.01E-08 8.38 1248.0 3.3 58.1 67.8 1.06E-08 1281.0 1.4 59.5 67.8 9.8E-09 1349.0 2.9 62.4 67.8 9.81E-09 1424.0 3.3 65.7 67.8 1.05E-08 8.35 1477.0 2.3 68.0 67.8 1.11E-08 1516.0 1.7 69.7 67.8 9.33E-09 1587.0 3.2 72.9 67.8 9.96E-09 1682.0 4.1 77.0 67.8 1.04E-08 1757.0 3.4 80.4 67.8 1.1E-08 1830.0 3.7 84.1 67.8 1.13E-08 8.26 1927.0 4.5 88.6 67.8 1.21E-08 2017.0 4.3 92.9 67.8 1.12E-08 Hydraulic conductivity, pH and [PCP] data for Run C7 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [PCP] Time (h) Flow (mL) (mg/L) 403.0 1.1 1.1 35.1 3.26E-09 0.00 427.5 1.3 2.4 34.8 3.48E-09 0.00 450.0 1.3 3.7 34.7 3.80E-09 0.00 498.0 19.8 23.5 34.7 2.71E-08 8.21 0.00 524.0 9.4 32.9 34.7 2.38E-08 8.15 0.00 550.0 8.6 41.5 34.7 2.18E-08 7.89 0.00 575.5 3.5 45.0 34.7 9.03E-09 0.00 Hydraulic conductivity, pH and [PCP] data for Run C8 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [PCP] Time (h) Flow (mL) (mg/L) 234.5 0.4 0.4 13.6 3.36E-09 0.00 261.0 1.1 1.3 13.6 6.97E-09 0.00 280.0 0.9 4.5 13.6 7.95E-09 0.00 309.0 3.2 9.4 22.8 1.10E-08 8.35 0.00 359.0 4.9 17.7 22.6 9.90E-09 0.00 381.0 8.3 23.1 35.3 2.44E-08 0.00 403.0 5.4 28.9 35.1 1.60E-08 7.99 0.00 427.5 5.8 33.2 34.8 1.55E-08 0.00 450.0 4.3 42.5 34.7 1.26E-08 0.00 498.0 9.3 48.0 34.7 1.27E-08 0.00 524.0 5.5 53.1 34.7 1.39E-08 8.09 0.00 550.0 5.1 55.8 34.7 1.29E-08 0.00 575.5 2.7 57.9 34.7 6.97E-09 0.00 594.5 2.1 60.1 34.7 7.27E-09 0.00 619.0 2.2 62.0 34.7 5.91E-09 0.00 645.5 1.9 65.9 34.7 4.72E-09 7.99 0.00 693.5 3.9 67.3 34.7 5.34E-09 0.00 717.5 1.4 68.6 34.7 3.84E-09 0.00 742.5 1.3 69.9 34.7 3.42E-09 0.00 768.5 1.3 70.9 34.7 3.29E-09 0.00 787.0 1.0 74.2 34.7 3.56E-09 7.87 0.00 861.5 3.3 75.7 34.7 2.91E-09 0.00 887.0 1.5 76.9 34.7 3.87E-09 0.00 913.0 1.2 77.9 34.7 3.04E-09 0.00 932.5 1.0 80.2 34.6 3.38E-09 0.00 984.0 2.3 82.2 34.6 2.95E-09 7.91 0.00 1030.0 2.0 83.4 34.6 2.87E-09 0.00 1054.0 1.2 84.5 34.6 3.30E-09 0.00 1077.0 1.1 85.4 34.6 3.16E-09 0.00 1099.5 0.9 90.5 34.6 2.64E-09 7.63 0.00 1217.5 5.1 91.3 25.8 3.82E-09 0.00 1242.0 0.8 92.6 34.4 2.17E-09 0.00 1271.0 1.3 96.5 34.4 2.98E-09 0.00 1359.0 3.9 97.8 34.1 2.96E-09 7.71 0.00 1386.5 1.3 98.7 33.9 3.18E-09 0.00 1437.0 0.9 100.1 33.7 1.21E-09 0.00 1479.5 1.4 101.2 33.7 2.23E-09 7.73 0.00 1505.0 1.1 102.1 33.7 2.93E-09 0.00 1530.0 0.9 102.6 33.7 2.44E-09 0.00 1554.5 0.5 103.6 33.7 1.38E-09 0.00 1581.0 1.0 104.1 33.7 2.56E-09 0.00 1605.0 0.5 106.2 33.9 1.40E-09 7.69 0.00 1671.0 2.1 107.1 33.9 2.14E-09 0.00 1699.0 0.9 110.7 33.9 2.16E-09 0.00 1798.0 3.6 112.6 33.7 2.47E-09 0.00 1840.5 1.9 113.9 33.7 3.03E-09 7.68 0.00 1869.0 1.3 114.9 33.7 3.09E-09 0.00 1890.0 1.0 116.0 33.7 3.23E-09 0.00 1913.5 1.1 117.1 33.7 3.17E-09 7.74 0.05 1935.5 1.1 122.1 33.9 3.37E-09 0.00 2026.0 5.0 123.3 33.7 3.75E-09 0.13 2049.0 1.2 124.4 33.7 3.54E-09 7.73 0.07 2070.5 1.1 127.1 33.7 3.47E-09 0.08 2124.0 2.7 128.6 33.7 3:42E-09 0.31 2152.5 1.5 130.5 33.7 3.45E-09 7.55 0.17 2188.0 1.9 130.5 33.7 3.63E-09 0.23 Hydraulic conductivity, pH and [PCP] data for Run C9 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [PCP] Time (h) Flow (mL) (me/L) 65.0 1.3 1.3 6:8 1.78E-08 0.00 93.0 1.1 2.4 6.7 1.34E-08 0.00 117.0 1.2 3.6 12.7 9.00E-09 0.00 141.0 1.8 5.4 12.2 1.40E-08 8.37 0.00 185.5 2.0 7.4 13.7 7.48E-09 0.00 214.5 0.6 8.0 13.6 3.47E-09 0.00 234.5 0.5 8.5 13.6 4.20E-09 0.00 261.0 0.5 9.0 13.6 3.17E-09 0.00 280.0 0.5 9.5 13.6 4.42E-09 8.29 0.00 309.0 1.6 11.1 22.8 5.52E-09 0.00 359.0 2.2 13.3 22.6 4.44E-09 0.00 381.0 2.8 16.1 35.3 8.24E-09 0.00 403.0 1.8 17.9 35.1 5.33E-09 0.00 427.5 2.3 20.2 34.8 6.16E-09 8.35 0.00 450.0 1.7 21.9 34.7 4.97E-09 0.00 498.0 4.5 26.4 34.7 6.17E-09 0.00 524.0 2.3 28.7 34.7 5.82E-09 0.00 550.0 1.9 30.6 34.7 4.81E-09 8.30 0.00 575.5 1.6 32.2 34.7 4.13E-09 0.00 594.5 1.3 33.5 34.7 4.50E-09 0.00 619.0 1.7 35.2 34.7 4.56E-09 0.00 645.5 1.7 36.9 34.7 4.22E-09 0.00 693.5 3.0 39.9 34.7 4.11E-09 8.28 0.00 717.5 1.4 41.3 34.7 3.84E-09 0.00 742.5 1.3 42.6 34.7 3.42E-09 0.00 768.5 1.3 43.9 34.7 3.29E-09 0.00 787.0 1.2 45.1 34.7 4.27E-09 7.99 0.00 861.5 3.6 48.7 34.7 3.18E-09 0.00 887.0 1.4 50.1 34.7 3.61E-09 0.00 913.0 1.1 51.2 34.7 2.78E-09 0.00 932.5 0.9 52.1 34.6 3.05E-09 8.17 0.00 984.0 2.2 54.3 34.6 2.82E-09 0.00 1030.0 2.0 56.3 34.6 2.87E-09 0.00 1054.0 1.2 57.5 34.6 3.30E-09 0.00 1077.0 0.9 58.4 34.6 2.58E-09 0.00 1099.5 1.0 59.4 34.6 2.93E-09 8.17 0.00 1217.5 3.7 63.1 25.8 2.77E-09 0.00 1242.0 1.0 64.1 34.4 2.71E-09 0.00 1271.0 0.9 65.0 34.4 2.06E-09 0.00 1359.0 4.2 69.2 34.1 3.19E-09 0.00 1386.5 1.2 70.4 33.9 2.94E-09 8.10 0.00 1437.0 2.3 72.7 33.7 3.09E-09 0.00 1479.5 3.2 75.9 33.7 5.11E-09 0.00 1505.0 4.2 80.1 33.7 1.12E-08 0.19 1530.0 2.3 82.4 33.7 6.24E-09 0.26 1554.5 2.1 84.5 33.7 5.81E-09 7.85 0.16 1581.0 2.2 86.7 33.7 5.63E-09 0.26 1605.0 2.1 88.8 33.9 5.89E-09 0.28 1671.0 5.3 94.1 33.9 5.41E-09 0.00 1699.0 2.8 96.9 33.9 6.73E-09 0.00 1798.0 62.0 158.9 33.7 4.25E-08 7.50 0.00 1840.5 96.4 255.3 33.7 1.54E-07 7.49 0.00 1869.0 13.8 269.1 33.7 3.28E-08 7.48 0.00 1890.0 15.9 285.0 33.7 5.13E-08 7.55 12.11 1913.5 24.5 309.5 33.7 7.07E-08 7.18 10.27 1935.5 26.7 336.2 33.9 8.17E-08 7.25 10.54 2026.0 75.1 41.1.3 33.7 5.63E-08 7.23 9.79 . 2049.0 27.8 439.1 33.7 8.20E-08 7.22 10.66 2070.5 40.7 479.8 33.7 1.28E-07 7.25 10.82 Hydraulic conductivity, pH and [PCP] data for Run CIO Elapsed Flow (mL) Cumulative Head k (cm/s) PH [PCP] Time (h) Flow (mL) (mg/L) 183.5 5.4 5.4 12.7 1.07E-08 0.00 206.5 2.0 7.4 12.7 1.57E-08 0.00 228.0 1.7 9.1 12.9 1.40E-08 7.95 0.00 281.5 4.2 13.3 12.9 1.39E-08 0.00 310.0 2.3 15.6 12.9 1.43E-08 0.00 345.5 2.7 18.3 12.7 1.37E-08 7.78 0.00 372.0 3.0 21.3 13.8 1.87E-08 0.00 419.0 4.9 26.2 13.6 1.75E-08 0.29 456.0 3.8 30.0 13.6 1.72E-08 0.74 496.0 3.8 33.8 13.6 1.59E-08 7.81 1.59 517.0 2.0 35.8 12.9 1.68E-08 1.91 541.0 2.2 38.0 12.7 1.65E-08 1.85 566.0 2.4 40.4 12.7 1.73E-08 7.83 2.33 588.5 2.2 42.6 12.7 1.76E-08 2.95 615.0 2.6 45.2 12.2 1.83E-08 .3.35 661.0 4.8 50.0 12.0 1.97E-08 4.33 684.5 2.4 52.4 12.0 1.94E-08 5.10 708.5 2.6 54.9 12.0 2.02E-08 7.91 4.92 Hydraulic conductivity, pH and [PCP] data for Run C l l Elapsed Flow (mL) Cumulative Head k (cm/s) pH [PCP] Time (h) Flow (mL) (mg/L) 26.5 3.0 3.0 12.7 2.04E-08 1.79 47.5 1.9 4.9 12.7 1.63E-08 0.00 71.0 1.9 6.8 12.7 1.46E-08 8.20 0.00 93.0 1.7 8.5 12.7 1.39E-08 0.00 183.5 7.9 16.4 12.7 1.57E-08 0.06 206.5 1.6 18.0 12.7 1.25E-08 0.00 228.0 1.6 19.6 12.9 1.32E-08 8.22 0.00 281.5 3.7 23.3 12.9 1.22E-08 0.00 310.0 2.5 25.8 12.9 1.52E-08 0.00 345.5 2.4 28.2 12.7 1.22E-08 0.00 372.0 2.2 30.4 13.8 1.37E-08 8.15 0.12 419.0 3.5 33.9 13.6 1.25E-08 0.44 456.0 3.0 36.9 13.6 1.36E-08 0.78 496.0 3.2 40.1 13.6 1.34E-08 1.12 517.0 1.7 41.8 12.9 1.43E-08 7.97 1.36 541.0 1.8 43.6 12.7 1.35E-08 1.54 566.0 1.9 45.5 12.7 1.37E-08 1.81 588.5 1.7 47.2 12.7 1.36E-08 8.01 2.18 615.0 2.2 49.4 12.2 1.55E-08 2.86 661.0 3.6 53.0 12.0 1.49E-08 3.53 684.5 1.9 54.9 12.0 1.54E-08 3.71 708.5 2.0 56.9 12.0 1.59E-08 8.00 3.59 Hydraulic conductivity, pH and [PCP] data for Run C12 Elapsed Time (h) Flow (mL) Cumulative Flow (mL) Head k (cm/s) pH [PCP] (mg/L) 26.5 4.8 4.8 12.7 3.26E-08 0.00 47.5 1.9 6.7 12.7 1.63E-08 0.00 71.0 2.0 8.7 12.7 1.53E-08 8.44 0.00 93.0 1.8 10.5 12.7 1.47E-08 0.00 183.5 8.3 18.8 12.7 1.65E-08 0.00 206.5 1.8 20.6 12.7 1.41E-08 8.16 0.00 228.0 1.5 22.1 12.9 1.23E-08 0.00 281.5 4.0 26.1 12.9 1.32E-08 0.00 310.0 2.1 28.2 12.9 1.30E-08 7.93 0.00 345.5 2.4 30.6 12.7 1.22E-08 0.00 372.0 4.2 34.8 13.8 2.62E-08 0.00 419.0 8.5 43.3 13.6 3.03E-08 0.29 456.0 10.0 53.3 13.6 4.54E-08 7.88 0.74 496.0 8.2 61.5 13.6 3.44E-08 1.59 517.0 5.8 67.3 12.9 4.88E-08 1.91 541.0 6.7 74.0 12.7 5.03E-08 1.85 566.0 7.9 81.9 12.7 5.69E-08 7.72 2.33 588.5 6.3 88.2 12.7 5.04E-08 2.95 615.0 7.2 95.4 12.2 5.08E-08 3.35 661.0 23.2 118.6 12.0 9.60E-08 4.33 684.5 6.9 125.5 12.0 5.59E-08 5.10 708.5 8.5 134.0 12.0 6.74E-08 7.75 5.39 Hydraulic conductivity, pH and [NP] data for Run C13 Elapsed Flow (mL) Cumulative Head k (cm/s) PH [NP] Time (h) Flow (mL) (mg/L) 21.0 22.9 22.9 33.2 4.50E-07 7.82 2.40 47.5 15.0 37.9 33.2 2.33E-07 7.62 1.50 73.0 77.1 115.0 33.2 1.25E-06 7.55 5.80 94.0 33.5 148.5 33.2 6.58E-07 7.23 4.00 117.0 44.8 193.3 69.2 3.86E-07 7.24 3.70 146.0 24.3 217.6 69.2 1.66E-07 7.21 2.60 165.5 12.6 230.2 69.2 1.28E-07 7.17 2.10 193.5 16.3 246.5 69.2 1.15E-07 7.17 1.90 214.0 60.3 306.8 69.2 5.82E-07 7.19 6.10 262.0 101.1 407.9 67.8 4.26E-07 7.20 5.20 291.0 41.3 449.2 67.8 2.88E-07 7.23 4.90 311.5 6.6 455.8 67.8 6.50E-08 7.24 1.70 336.5 4.7 460.5 66.4 3.88E-08 7.18 0.90 357.0 3.6 464.1 66.4 3.62E-08 0.70 381.0 3.9 468.0 66.4 3.35E-08 7.19 0.44 405.0 3.6 471.6 66.4 3.09E-08 0.41 456.0 7.5 479.1 66.4 3.03E-08 7.21 0.52 479.0 3.2 482.3 66.4 2.87E-08 0.22 508.5 4.8 487.1 66.4 3.36E-08 7.23 0.40 547.0 5.0 492.1 67.8 2.62E-08 0.45 619.5 32.1 524.2 67.8 8.95E-08 7.17 1.99 Hydraulic conductivity, pH and [NP] data for Run C14 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [NP] Time (h) Flow (mL) (mg/L) 117.0 102.0 102.0 69.2 8.78E-07 7.21 4.90 146.0 74.8 176.8 69.2 5.11E-07 7.15 4.70 165.5 33.8 210.6 69.2 3.43E-07 7.24 4.30 193.5 46.2 256.8 69.2 3.27E-07 7.26 4.20 214.0 35.6 292.4 69.2 3.44E-07 7.25 4.80 262.0 66.1 358.5 67.8 2.78E-07 7.25 4.20 291.0 35.4 393.9 67.8 2.47E-07 7.26 4.30 311.5 22.6 416.5 67.8 2.23E-07 7.26 3.80 336.5 25.2 441.7 66.4 2.08E-07 7.19 4.00 357.0 21.3 463.0 66.4 2.14E-07 7.20 4.10 381.0 25.6 488.6 66.4 2.20E-07 7.21 3.98 405.0 25.7 514.3 66.4 2.21E-07 7.22 4.12 456.0 59.2 573.5 66.4 2.39E-07 7.23 3.95 479.0 23.2 596.7 66.4 2.08E-07 7.24 3.96 508.5 37.1 633.8 66.4 2.59E-07 7.26 4.32 547.0 46.2 680.0 67.8 2.42E-07 7.19 4.22 619.5 65.3 745.3 67.8 1.82E-07 7.20 3.74 Hydraulic conductivity, pH and [NP] data for Run C15 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [NP] Time (h) Flow (mL) (mg/L) 117.0 2.8 2.8 69.2 2.41E-08 Trace 146.0 3.1 5.9 69.2 2.12E-08 0.00 165.5 1.8 7.7 69.2 1.83E-08 8.08 0.00 193.5 2.2 9.9 69.2 1.56E-08 0.00 214.0 2.5 12.4 69.2 2.41E-08 0.00 262.0 5.4 17.8 67.8 2.27E-08 8.15 0.00 291.0 3.4 21.2 67.8 2.37E-08 Trace 311.5 2.1 23.3 67.8 2.07E-08 Trace 336.5 2.0 25.3 66.4 1.65E-08 Trace 357.0 1.7 . 27.0 66.4 1.71E-08 8.23 Trace 381.0 2.1 29.1 66.4 1.80E-08 0.00 405.0 2.0 31.1 66.4 1.72E-08 0.00 456.0 4.4 35.5 66.4 1.78E-08 0.00 479.0 1.8 37.3 66.4 1.61E-08 8.05 0.00 508.5 2.5 39.8 66.4 1.75E-08 0.00 547.0 2.7 42.5 67.8 1.42E-08 0.00 619.5 6.5 49.0 67.8 1.81E-08 0.00 643.0 33.7 82.7 30.5 2.84E-07 3.00 672.5 8.0 90.7 69.2 5.37E-08 7.98 0.52 693.0 4.6 95.3 69.2 4.44E-08 0.31 763.5 13.2 108.5 69.2 • 3.71E-08 7.95 0.22 788.0 4.1 112.6 69.2 3.31E-08 0.12 814.0 3.8 116.4 69.2 2.89E-08 7.75 0.00 859.0 5.7 122.1 69.2 2.51E-08 0.00 958.0 15.8 137.9 69.2 3.10E-08 7.70 0.30 1030.0 14.4 152.3 70.6 4.04E-08 0.36 1084.5 10.4 162.7 67.8 3.86E-08 7.42 0.23 1106.0 6.8 169.5 67.8 6.39E-08 0.32 1184.5 13.6 183.1 67.8 3.50E-08 7.51 0.30 1235.5 12.7 195.8 67.8 5.03E-08 0.37 1254.0 3.7 199.5 67.8 4.04E-08 7.49 0.27 Hydraulic conductivity, pH and [NP] data for Run C16 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [NP] Time (h) Flow (mL) (mg/L) 160.5 2.2 2.2 69.2 2.12E-08 0.00 185.0 9.2 11.4 69.2 2.58E-08 8.21 0.00 211.0 3.3 14.7 69.2 2.67E-08 0.00 256.0 2.9 17.6 69.2 2.21E-08 0.00 355.0 4.2 21.8 69.2 1.85E-08 8.11 0.00 427.0 9.0 30.8 70.6 1.76E-08 0.00 481.5 6.0 36.8 67.8 1.68E-08 0.00 503.0 7.6 44.4 67.8 2.02E-08 8.15 0.00 581.5 6.8 51.2 67.8 1.75E-08 0.00 632.5 6.8 58.0 67.8 2.69E-08 0.00 651.0 2.3 60.3 67.8 2.51E-08 8.08 0.00 Hydraulic conductivity, pH and [NP] data for Run C17 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [NP] Time (h) Flow (mL) (mg/L) 40.0 3.0 3.0 69.2 2.53E-08 0.00 69.5 54.5 57.5 69.2 3.66E-07 8.10 1.47 90.0 36.1 93.6 69.2 3.49E-07 7.99 2.82 160.5 55.1 148.7 69.2 1.55E-07 7.92 2.17 185.0 14.1 162.8 69.2 1.14E-07 7.50 1.70 211.0 13.3 176.1 69.2 1.01E-07 7.53 1.48 256.0 21.7 197.8 69.2 9.55E-08 7.49 1.71 355.0 55.3 253.1 70.6 1.08E-07 7.28 1.98 427.0 43.0 296.1 67.8 1.21E-07 7.39 2.91 481.5 32.9 329.0 67.8 1.22E-07 7.37 2.14 503.0 19.3 348.3 67.8 1.81E-07 7.42 2.20 581.5 38.3 386.6 67.8 9.86E-08 7.21 2.09 632.5 35.6 422.2 67.8 1.41E-07 7.19 1.79 651.0 10.1 432.3 67.8 1.10E-07 7.28 1.68 Hydraulic conductivity, pH and [NP] data for Run C18 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [NP] Time (h) Flow (mL) (mg/L) 75.5 1.8 1.8 69.2 6.92E-09 0.00 99.5 1.7 3.5 72.0 1.35E-08 0.00 124.5 1.7 5.2 72.0 1.29E-08 8.41 0.00 171.5 2.9 8.1 72.0 1.17E-08 0.00 194.5 1.4 9.5 72.0 1.16E-08 0.00 218.5 1.5 11.0 72.0 1.19E-08 0.00 243.0 1.3 12.3 72.0 1.01E-08 8.38 0.00 263.0 1.2 13.5 73.4 1.12E-08 0.00 315.5 3.0 16.5 73.4 1.07E-08 0.00 339.5 1.3 17.8 73.4 1.01E-08 0.00 362.5 1.1 18.9 73.4 8.93E-09 8.40 0.00 385.5 1.4 20.3 73.4 1.14E-08 0.00 411.5 1.4 21.7 73.4 1.01E-08 0.00 431.5 1.0 22.7 73.4 9.34E-09 8.39 0.00 508.5 4.0 26.7 73.4 9.70E-09 0.00 554.5 2.4 29.1 73.4 9.75E-09 0.00 578.5 1.2 30.3 73.4 9.34E-09 8.41 0.00 599.5 1.0 31.3 73.4 8.90E-09 0.00 628.5 1.6 32.9 73.4 1.03E-08 0.00 672.5 2.2 35.1 73.4 9.34E-09 0.00 699.5 1.3 36.4 73.4 8.99E-09 8.42 0.00 719.5 0.9 37.3 73.4 8.41E-09 0.00 748.5 1.5 38.8 73.4 9.66E-09 0.00 766.5 0.8 39.6 73.4 8.30E-09 8.36 0.00 795.5 1.5 41.1 73.4 9.66E-09 0.00 843.5 2.3 43.4 73.4 8.95E-09 0.00 866.5 1.3 44.7 73.4 1.06E-08 0.00 887.5 1.0 45.7 73.4 8.90E-09 8.32 0.00 986.5 5.6 51.3 73.4 1.06E-08 0.00 1009.5 1.1 52.4 73.4 8.93E-09 0.00 1058.5 2.3 54.7 73.4 8.77E-09 0.00 1106.5 2.2 56.9 73.4 8.56E-09 8.28 0.00 1125.5 0.9 57.8 73.4 8.85E-09 0.00 1152.5 1.2 59.0 73.4 8.30E-09 0.00 1178.5 1.3 60.3 73.4 9.34E-09 0.00 1201.5 1.1 61.4 73.4 8.93E-09 8.31 0.00 1226.5 1.2 62.6 73.4 8.97E-09 0.00 1321.5 4.2 66.8 73.4 8.26E-09 0.00 1348.5 1.4 68.2 73.4 9.69E-09 8.34 0.00 1368.5 1.1 69.3 73.4 1.03E-08 0.00 1391.5 1.0 70.3 73.4 8.12E-09 0.00 1417.5 1.2 - 71.5 73.4 8.62E-09 8.27 0.00 1442.5 1.1 72.6 73.4 8.22E-09 0.00 1515.5 3.1 75.7 73.4 7.93E-09 0.00 1537.5 0.9 76.6 73.4 7.64E-09 0.00 1561.5 1.2 77.8 73.4 9.34E-09 8.30 0.00 1586.5 1.3 79.1 73.4 9.71E-09 0.00 1610.5 1.2 80.3 73.4 9.34E-09 0.00 1630.5 1.0 81.3 73.4 9.34E-09 8.33 0.00 1659.5 1.4 82.7 73.4 9.02E-09 0.00 1681.5 1.1 83.8 73.4 9.34E-09 0.00 1705.5 1.3 85.1 73.4 1.01E-08 8.31 0.00 Hydraulic conductivity, pH and [NP] data for Run C19 Elapsed Time (h) Flow (mL) Cumulative Flow (mL) Head k (cm/s) pH [NP] (mg/L) 75.5 2.5 2.5 69.2 9.61E-09 0.00 99.5 1.5 4.0 72.0 1.19E-08 0.00 124.5 1.4 5.4 72.0 1.07E-08 8.32 0.00 171.5 2.7 8.1 72.0 1.09E-08 0.00 194.5 1.4 9.5 72.0 1.16E-08 0.00 218.5 1.4 10.9 72.0 1.11E-08 8.22 0.00 243.0 1.3 12.2 72.0 1.01E-08 0.00 263.0 1.0 13.2 73.4 9.34E-09 0.00 315.5 3.0 16.2 73.4 1.07E-08 0.00 339.5 1.4 17.6 73.4 1.09E-08 8.25 0.00 362.5 1.1 18.7 73.4 8.93E-09 0.00 385.5 1.3 20.0 73.4 1.06E-08 0.00 411.5 1.4 21.4 73.4 1.01E-08 8.12 0.00 431.5 1.0 22.4 73.4 9.34E-09 0.00 508.5 4.0 26.4 73.4 9.70E-09 0.00 554.5 2.4 28.8 73.4 9.75E-09 8.15 0.00 578.5 1.2 30.0 73.4 9.34E-09 0.00 599.5 1.0 31.0 73.4 8.90E-09 0.00 628.5 1.5 32.5 73.4 9.66E-09 0.00 672.5 2.1 34.6 73.4 8.92E-09 8.18 0.00 699.5 1.2 35.8 73.4 8.30E-09 0.00 719.5 1.0 36.8 73.4 9.34E-09 0.00 748.5 1.5 38.3 73.4 9.66E-09 0.00 766.5 0.8 39.1 73.4 8.30E-09 8.10 0.00 795.5 1.4 40.5 73.4 9.02E-09 0.00 843.5 2.3 42.8 73.4 8.95E-09 0.00 866.5 1.1 43.9 73.4 8.93E-09 8.06 0.00 887.5 1.1 45.0 73.4 9.78E-09 0.00 986.5 4.5 49.5 73.4 8.49E-09 0.00 1009.5 1.1 50.6 73.4 8.93E-09 8.01 0.00 1058.5 2.4 53.0 73.4 9.15E-09 0.00 1106.5 2.2 55.2 73.4 8.56E-09 0.00 1125.5 0.9 56.1 73.4 8.85E-09 8.11 0.00 1152.5 1.3 57.4 73.4 8.99E-09 0.00 1178.5 1.3 58.7 73.4 9.34E-09 0.00 1201.5 1.1 59.8 73.4 8.93E-09 0.00 1226.5 1.2 61.0 73.4 8.97E-09 7.99 0.00 1321.5 4.5 65.5 73.4 8.85E-09 0.00 1348.5 1.7 67.2 73.4 1.18E-08 0.00 1368.5 0.9 68.1 73.4 8.41E-09 7.95 0.00 1391.5 1.1 69.2 73.4 8.93E-09 0.00 1417.5 1.2 70.4 73.4 8.62E-09 0.00 1442.5 1.2 71.6 73.4 8.97E-09 0.00 1515.5 4.2 75.8 73.4 1.07E-08 8.00 0.00 1537.5 1.5 77.3 73.4 1.27E-08 0.00 1561.5 1.2 78.5 73.4 9.34E-09 0.00 1586.5 1.2 79.7 73.4 8.97E-09 7.87 0.00 1610.5 1.1 80.8 73.4 8.56E-09 0.00 1630.5 0.9 81.7 73.4 8.41E-09 0.00 1659.5 1.4 83.1 73.4 9.02E-09 0.00 1681.5 1.1 84.2 73.4 9.34E-09 7.88 0.00 1705.5 1.3 85.5 73.4 1.01E-08 0.00 Hydraulic conductivity, pH and [TL] data for Run C20 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [TL] Time (h) Flow (mL) (mg/L) 117.0 98.0 98.0 73.4 3.98E-07 7.69 0.00 144.0 151.2 249.2 73.4 1.05E-06 7.65 0.00 166.0 134.3 383.5 72.0 1.16E-06 7.62 0.00 188.0 109.1 492.6 72.0 9.44E-07 7.63 0.00 214.0 132.2 624,8 72.0 9.68E-07 7.61 0.00 239.0 87.8 712.6 72.0 6.69E-07 7.66 0.00 263.0 70.9 783.5 72.0 5.62E-07 7.70 0.00 288.0 56.9 840.4 72.0 4.33E-07 7.55 0.00 310.0 47.6 888.0 72.0 4.12E-07 7.52 0.00 336.0 51.3 939.3 72.0 3.76E-07 7.54 0.00 360.0 44.4 983.7 72.0 3.52E-07 7.55 0.00 390.0 53.9 1037.6 72.0 3.42E-07 7.51 0.00 415.0 40.6 1078.2 72.0 3.09E-07 7.50 0.00 431.0 26.3 1104.5 72.0 3.13E-07 7.56 0.00 457.0 36.7 1141.2 72.0 2.69E-07 7.54 0.00 504.0 63.9 1205.1 72.0 2.59E-07 7.71 0.00 525.0 25.9 1231.0 72.0 2.35E-07 7.53 0.00 576.0 59.2 1290.2 72.0 2.21E-07 7.56 0.00 601.0 26.2 1316.4 72.0 2.00E-07 7.57 0.00 623.0 20.7 1337.1 72.0 1.79E-07 7.55 0.00 649.0 25.1 1362.2 72.0 1.84E-07 7.54 0.00 674.0 24.9 1387.1 72.0 1.90E-07 7.50 0.00 695.0 21.6 1408.7 72.0 1.96E-07 7.54 0.00 744.0 45.2 1453.9 72.0 1.76E-07 7.54 0.00 768.0 19.5 1473.4 72.0 1.55E-07 7.55 0.00 795.0 18.7 1492.1 72.0 1.32E-07 7.59 0.00 820.0 15.4 1507.5 72.0 1.17E-07 7.53 0.00 842.0 12.0 1519.5 72.0 1.04E-07 7.53 0.00 889.0 23.8 1543.3 72.0 9.64E-08 7.51 0.00 911.0 16.5 1559.8 72.0 1.43E-07 7.54 0.00 938.0 21.3 1581.1 70.6 1.53E-07 7.55 0.00 1009.0 40.7 1621.8 70.6 1.11E-07 7.56 0.00 1061.0 41.3 1663.1 70.6 1.54E-07 7.55 0.00 1083.0 19.9 1683.0 70.6 1.76E-07 7.60 0.00 1108.0 21.5 1704.5 70.6 1.67E-07 7.61 0.00 1123.0 12.8 1717.3 70.6 1.66E-07 7.57 0.00 1179.0 33.1 1750.4 70.6 1.15E-07 7.58 0.00 1203.0 8.8 1759.2 70.6 7.12E-08 7.55 0.00 1248.0 15.7 1774.9 70.6 6.77E-08 7.51 0.00 1269.0 8.7 1783.6 70.6 8.04E-08 7.53 0.00 1324.0 23.3 1806.9 70.6 8.22E-08 7.55 0.00 1347.0 10.0 1816.9 70.6 8.44E-08 7.58 0.00 1391.0 17.3 1834.2 70.6 7.63E-08 7.59 0.00 1416.0 10.0 1844.2 70.6 7.76E-08 7.54 0.00 1439.0 9.0 1853.2 70.6 7.60E-08 7.56 0.00 1489.0 17.1 1870.3 70.6 6.64E-08 7.58 0.00 1508.0 6.7 1877.0 70.6 6.85E-08 7.57 0.00 1541.0 10.5 1887.5 70.6 6.18E-08 7.56 0.00 1558.0 5.8 1893.3 70.6 6.62E-08 7.56 0.00 Hydraulic conductivity, pH and [TL] data for Run C21 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [TL] Time (h) Flow (mL) (mg/L) 45.0 154.2 154.2 73.4 1.20E-06 7.81 0.00 71.0 121.9 276.1 73.4 8.76E-07 7.81 0.00 117.0 126.7 402.8 73.4 5.15E-07 7.81 0.00 144.0 50.4 453.2 73.4 3.49E-07 7.77 0.00 166.0 30.7 483.9 72.0 2.66E-07 7.78 0.00 188.0 25.0 508.9 72.0 2.16E-07 7.65 0.00 214.0 24.4 533.3 72.0 1.79E-07 7.75 0.00 239.0 18.2 551.5 72.0 1.39E-07 7.74 0.00 263.0 17.8 569.3 72.0 1.41E-07 7.73 0.00 288.0 16.5 585.8 72.0 1.26E-07 7.60 0.00 310.0 14.6 600.4 72.0 1.26E-07 7.50 0.00 336.0 16.2 616.6 72.0 1.19E-07 7.49 0.00 360.0 14.5 631.1 72.0 1.15E-07 7.61 0.00 390.0 17.7 648.8 72.0 1.12E-07 7.63 0.00 415.0 14.9 663.7 72.0 1.13E-07 7.55 0.00 431.0 9.9 673.6 72.0 1.18E-07 7.54 0.00 457.0 16.1 689.7 72.0 1.18E-07 7.56 0.00 504.0 29.7 719.4 72.0 1.20E-07 7.69 0.00 525.0 13.0 732.4 72.0 1.18E-07 7.55 0.00 576.0 30.4 762.8 72.0 1.13E-07 7.54 0.00 601.0 17.6 780.4 72.0 1.34E-07 7.58 0.00 623.0 12.6 793.0 72.0 1.09E-07 7.56 0.00 649.0 15.6 808.6 72.0 1.14E-07 7.57 674.0 15.3 823.9 72.0 1.17E-07 7.51 0.00 695.0 12.8 836.7 72.0 1.16E-07 7.59 0.00 744.0 29.6 866.3 72.0 1.15E-07 7.55 0.00 768.0 15.4 881.7 72.0 1.22E-07 7.57 0.00 795.0 17.1 898.8 72.0 1.21E-07 7.57 0.00 820.0 15.9 914.7 72.0 1.21E-07 7.55 0.00 842.0 14.6 929.3 72.0 1.26E-07 7.55 0.00 889.0 30.2 959.5 72.0 1.22E-07 7.53 0.00 911.0 14.3 973.8 72.0 1.24E-07 7.52 0.00 938.0 17.4 991.2 70.6 1.25E-07 7.56 0.00 1009.0 44.0 1035.2 70.6 1.20E-07 7.57 0.00 1061.0 34.8 1070.0 70.6 1.30E-07 7.45 0.00 1083.0 15.5 1085.5 70.6 1.37E-07 7.49 0.00 1108.0 17.8 1103.3 70.6 1.38E-07 7.48 0.00 1123.0 11.1 1114.4 70.6 1.44E-07 7.49 0.00 1179.0 37.1 1151.5 70.6 1.29E-07 7.53 0.00 1203.0 16.0 1167.5 70.6 1.29E-07 7.51 0.00 1248.0 19.3 1186.8 70.6 8.33E-08 7.49 0.00 1269.0 14.4 1201.2 70.6 1.33E-07 7.50 0.00 1324.0 38.3 1239.5 70.6 1.35E-07 7.49 0.00 1347.0 16.4 1255.9 70.6 1.38E-07 7.48 0.00 1391.0 28.7 1284.6 70.6 1.27E-07 7.40 0.00 1416.0 15.9 1300.5 70.6 1.23E-07 7.52 0.00 1439.0 15.4 1315.9 70.6 1.30E-07 7.51 0.00 1489.0 31.8 1347.7 70.6 1.23E-07 7.51 0.00 1508.0 13.6 1361.3 70.6 1.39E-07 7.53 0.00 1541.0 22.6 1383.9 70.6 1.33E-07 7.50 0.00 1558.0 12.5 1396.4 70.6 1.43E-07 7.49 0.00 Hydraulic conductivity, pH and [TL] data for Run C22 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [TL] Time (h) Flow (mL) (mg/L) 144.0 1.1 1.1 73.4 7.61E-09 0.00 166.0 1.3 2.4 72.0 1.13E-08 8.31 0.00 188.0 1.2 3.6 72.0 1.04E-08 0.00 214.0 1.5 5.1 72.0 1.10E-08 0.00 239.0 1.5 6.6 72.0 1.14E-08 0.00 263.0 1.4 8.0 72.0 ' 1.11E-08 8.18 0.00 288.0 1.5 9.5 72.0 1.14E-08 0.00 310.0 1.2 10.7 72.0 1.04E-08 0.00 336.0 1.6 12.3 72.0 1.17E-08 8.19 0.00 360.0 1.4 13.7 72.0 1.11E-08 0.00 390.0 1.7 15.4 72.0 1.08E-08 0.00 415.0 1.4 16.8 72.0 1.07E-08 0.00 431.0 0.8 17.6 72.0 9.52E-09 7.99 0.00 457.0 1.4 19.0 72.0 1.03E-08 0.00 504.0 2.6 21.6 72.0 1.05E-08 0.00 525.0 1.1 22.7 72.0 9.97E-09 7.98 0.00 576.0 2.7 25.4 72.0 1.01E-08 0.00 601.0 1.3 26.7 72.0 9.90E-09 0.00 623.0 1.1 27.8 ' 72.0 9.52E-09 0.00 649.0 1.4 29.2 72.0 1.03E-08 8.01 0.00 674.0 1.3 30.5 72.0 9.90E-09 0.00 695.0 1.0 31.5 72.0 9.07E-09 0.00 744.0 2.4 33.9 72.0 9.33E-09 8.03 0.00 768.0 1.2 35.1 72.0 9.52E-09 0.00 795.0 1.3 36.4 72.0 9.17E-09 0.00 820.0 1.2 37.6 72.0 9.14E-09 0.00 842.0 1.1 38.7 72.0 9.52E-09 8.01 0.00 889.0 2.2 40.9 72.0 8.91E-09 0.00 911.0 0.9 41.8 72.0 7.79E-09 0.00 938.0 1.3 43.1 70.6 9.35E-09 0.00 1009.0 3.3 46.4 70.6 9.02E-09 7.95 0.00 1061.0 2.5 48.9 70.6 9.33E-09 0.00 1083.0 1.0 49.9 70.6 8.82E-09 0.00 1108.0 . 1.2 51.1 70.6 9.32E-09 0.00 1123.0 0.7 51.8 70.6 9.06E-09 7.90 0.00 1179.0 2.5 54.3 70.6 8.67E-09 0.00 1203.0 1.2 55.5 70.6 9.71E-09 0.00 1248.0 2.1 57.6 70.6 9.06E-09 7.83 0.00 1269.0 0.8 58.4 70.6 7.40E-09 0.00 1324.0 2.6 61.0 70.6 9.18E-09 0.00 1347.0 1.0 62.0 70.6 8.44E-09 0.00 1391.0 2.0 64.0 70.6 8.82E-09 7.64 0.00 1416.0 1.1 65.1 70.6 8.54E-09 0.00 1439.0 1.1 66.2 70.6 9.28E-09 0.00 1489.0 2.2 68.4 70.6 8.54E-09 0.00 1508.0 0.9 69.3 70.6 9.20E-09 7.74 0.00 1541.0 1.5 70.8 70.6 8.82E-09 0.00 1558.0 0.8 71.6 70.6 9.14E-09 0.00 Hydraulic conductivity, pH and [MEK] data for Run C23 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [MEK] Time(h) Flow (mL) (mg/L) 504.0 1.3 1.3 73.4 9.34E-09 0.00 529.0 1.4 2.7 73.4 1.05E-08 0.00 558.0 1.6 4.3 73.4 1.03E-08 8.33 0.00 599.0 2.5 6.8 73.4 1.14E-08 0.00 619.0 1.3 8.1 73.4 1.21E-08 0.00 649.0 1.9 10.0 73.4 1.18E-08 0.00 671.0 1.5 11.5 73.4 1.27E-08 8.28 0.00 697.0 1.7 13.2 73.4 1.22E-08 0.00 717.0 1.6 14.8 73.4 1.49E-08 0.00 744.0 1.9 16.7 73.4 1.31E-08 0.00 766.0 1.5 18.2 73.4 1.27E-08 8.15 0.00 794.0 1.7 19.9 73.4 1.13E-08 0.00 816.0 1.7 21.6 73.4 1.44E-08 0.00 840.0 1.5 23.1 73.4 1.17E-08 0.00 864.0 1.6 24.7 73.4 1.25E-08 8.08 0.00 889.0 1.7 26.4 73.4 1.27E-08 0.00 910.0 1.3 27.7 73.4 1.16E-08 0.00 937.0 1.6 29.3 73.4 1.11E-08 8.07 0.00 961.0 1.6 30.9 73.4 1.25E-08 0.00 984.0 1.4 32.3 73.4 1.14E-08 0.00 1010.0 1.8 34.1 73.4 1.29E-08 0.00 1033.0 1.2 35.3 73.4 9.75E-09 7.97 0.00 1052.0 1.2 36.5 73.4 1.18E-08 0.00 1104.0 3.0 39.5 73.4 1.08E-08 0.00 1124.0 1.3 40.8 73.4 1.21E-08 0.00 1152.0 1.7 42.5 73.4 1.13E-08 7.92 0.00 1176.0 1.4 43.9 73.4 1.09E-08 0.00 1201.0 1.4 45.3 73.4 1.05E-08 0.00 1248.0 2.5 47.8 73.4 9.94E-09 7.96 0.00 1273.0 1.6 49.4 73.4 1.20E-08 0.00 1299.0 1.2 50.6 73.4 8.62E-09 0.00 1321.0 0.9 51.5 73.4 7.64E-09 0.00 1343.0 1.2 52.7 73.4 1.02E-08 7.75 0.00 1369.0 1.3 54.0 73.4 9.34E-09 0.00 1392.0 1.1 55.1 73.4 8.93E-09 0.00 1441.0 2.3 57.4 73.4 8.77E-09 7.91 0.00 1463.0 0.9 58.3 73.4 7.64E-09 0.00 1490.0 1.2 59.5 73.4 8.30E-09 0.00 1513.0 1.0 60.5 73.4 8.12E-09 7.85 0.00 1533.0 0.8 61.3 73.4 7.47E-09 0.00 1581.0 2.2 63.5 73.4 8.56E-09 0.00 Hydraulic conductivity, pH and [MEK] data for Run C24 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [MEK] Time (h) Flow (mL) (mg/L) 143 2.5 2.5 74.7 1.76E-08 0.00 165 1.4 3.9 74.7 1.17E-08 0.00 192 1.8 5.7 74.7 ' 1.22E-08 8.21 0.00 218 2.0 7.7 74.7 1.41E-08 0.00 263 3.0 10.7 74.7 1.22E-08 0.00 288 1.8 12.5 74.7 1.32E-08 0.00 316 2.2 14.7 73.4 1.47E-08 8.15 0.00 336 1.6 16.3 73.4 1.49E-08 0.00 361 1.6 17.9 73.4 1.20E-08 0.00 434 5.4 23.3 73.4 1.38E-08 8.16 0.00 459 1.9 25.2 73.4 1.42E-08 0.00 478 1.4 26.6 73.4 1.38E-08 0.00 504 1.9 28.5 73.4 1.37E-08 7.94 0.00 529 2.1 30.6 73.4 1.57E-08 0.00 558 2.2 32.8 73.4 1.42E-08 0.00 599 3.2 36.0 73.4 1.46E-08 0.00 619 1.9 37.9 73.4 1.77E-08 7.98 0.00 649 2.4 40.3 73.4 1.49E-08 0.00 671 1.9 42.2 73.4 1.61E-08 0.00 697 2.5 44.7 73.4 1.80E-08 7.89 0.00 717 1.9 46.6 73.4 1.77E-08 0.00 744 2.7 49.3 73.4 1.87E-08 0.00 766 2.2 51.5 73.4 1.87E-08 7.92 0.00 794 2.9 54.4 73.4 1.93E-08 0.00 816 2.3 56.7 73.4 1.95E-08 0.00 840 2.5 59.2 73.4 1.95E-08 7.93 0.00 864 2.5 61.7 73.4 1.95E-08 0.00 889 2.7 64.4 73.4 2.02E-08 0.00 910 2.1 66.5 73.4 1.87E-08 0.00 937 3.0 69.5 73.4 2.08E-08 7.99 0.00 961 2.8 72.3 73.4 2.18E-08 0.00 984 2.9 75.2 73.4 2.36E-08 0.00 1010 4.3 79.5 • 73.4 3.09E-08 0.00 1033 4.4 83.9 73.4 3.57E-08 8.01 0.00 1052 3.4 87.3 73.4 3.34E-08 0.00 1104 10.5 97.8 73.4 3.77E-08 0.00 1124 4.4 102.2 73.4 4.11E-08 0.00 1152 5.6 107.8 73.4 3.74E-08 7.95 0.00 1176 4.6 112.4 73.4 3.58E-08 0.00 1201 4.9 117.3 73.4 3.66E-08 0.00 1248 9.2 126.5 73.4 3.66E-08 0.00 1273 5.3 131.8 73.4 3.96E-08 7.96 0.00 1299 5.2 137.0 73.4 3.74E-08 0.00 1321 4.5 141.5 73.4 3.82E-08 0.00 1343 4.8 146.3 73.4 4.08E-08 7.95 0.00 1369 6.0 152.3 73.4 4.31E-08 0.00 1392 5.8 158.1 73.4 4.71E-08 0.00 1441 13.9 172.0 73.4 5.30E-08 7.97 0.00 1463 6.5 178.5 73.4 5.52E-08 0.00 1490 8.2 186.7 73.4 5.67E-08 0.00 1513 7.6 194.3 73.4 6.17E-08 7.97 0.00 1533 6.6 200.9 73.4 6.16E-08 0.00 1581 16.4 217.3 73.4 6.38E-08 0.00 Hydraulic conductivity, pH and [MEK] data for Run C25 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [MEK] Time (h) Flow (mL) (mg/L) 143 2.6 2.6 74.7 1.83E-08 0.00 165 1.5 4.1 74.7 1.25E-08 8.09 0.00 192 2.1 6.2 74.7 1.43E-08 7.98 0.00 218 2.0 8.2 74.7 1.41E-08 7.88 0.00 263 3.9 12.1 74.7 1.59E-08 7.69 0.00 288 2.4 14.5 74.7 1.76E-08 7.60 0.00 316 2.8 17.3 73.4 1.87E-08 7.55 0.00 336 2.2 19.5 73.4 2.05E-08 7.54 0.00 361 2.9 22.4 73.4 2.17E-08 7.45 0.00 434 8.3 30.7 73.4 2.12E-08 7.33 0.00 459 . 3.2 33.9 73.4 2.39E-08 7.21 0.00 478 2.1 36.0 73.4 2.06E-08 7.15 0.00 504 3.2 39.2 73.4 2.30E-08 7.09 0.00 529 3.0 42.2 73.4 2.24E-08 7.22 0.00 558 3.2 45.4 73.4 2.06E-08 7.23 0.00 599 5.0 50.4 73.4 2.28E-08 7.26 0.00 619 2.3 52.7 73.4 2.15E-08 7.25 0.00 649 3.7 56.4 73.4 2.30E-08 7.21 0.00 671 2.5 58.9 73.4 2.12E-08 7.19 0.00 697 3.1 62.0 73.4 2.23E-08 7.21 0.00 717 2.5 64.5 73.4 2.33E-08 7.20 0.00 744 3.1 67.6 73.4 2.14E-08 7.27 0.00 766 2.6 70.2 73.4 2.21E-08 7.19 0.00 794 3.2 73.4 73.4 2.13E-08 7.25 0.00 816 2.6 76.0 73.4 2.21E-08 7.26 0.00 840 2.9 78.9 73.4 2.26E-08 7.24 0.00 864 2.9 81.8 73.4 2.26E-08 7.23 0.00 889 3.2 85.0 73.4 2.39E-08 7.23 0.00 910 2.5 87.5 73.4 2.22E-08 7.23 0.00 937 3.2 90.7 73.4 2.21E-08 7.26 0.00 961 3.1 93.8 73.4 2.41E-08 7.25 0.00 984 2.8 96.6 73.4 2.27E-08 7.29 0.00 1010 3.4 100.0 73.4 2.44E-08 7.26 0.00 1033 2.7 102.7 73.4 2.19E-08 7.23 0.00 1052 2.4 105.1 73.4 2.36E-08 7.27 0.00 1104 6.8 111.9 73.4 2.44E-08 7.31 0.00 1124 3.0 114.9 73.4 2.80E-08 7.20 0.00 1152 3.8 118.7 73.4 2.54E-08 7.19 0.00 1176 3.3 122.0 73.4 2.57E-08 7.22 0.00 1201 3.7 125.7 73.4 2.76E-08 7.22 0.00 1248 6.5 132.2 73.4 2.58E-08 7.24 0.00 1273 3.9 136.1 73.4 2.91E-08 7.26 0.00 1299 3.8 139.9 73.4 2.73E-08 7.23 0.00 1321 3.4 143.3 73.4 2.89E-08 7.20 0.00 1343 3.5 146.8 73.4 2.97E-08 7.17 0.00 1369 4.3 151.1 73.4 3.09E-08 7.18 0.00 1392 3.8 154.9 73.4 3.09E-08 7.21 0.00 1441 8.6 163.5 73.4 3.28E-08 7.22 0.00 1463 3.9 167.4 73.4 3.31E-08 7.21 0.00 1490 5.0 172.4 73.4 3.46E-08 7.23 0.00 1513 4.3 176.7 73.4 3.49E-08 7.21 0.00 1533 3.5 180.2 73.4 3.27E-08 7.19 0.00 1581 9.2 189.4 73.4 3.58E-08 7.17 0.00 Hydraulic conductivity and pH data for Run El Elapsed Flow (mL) Cumulative Head k (cm/s) pH Time (h) Flow (mL) 41.5 34.0 34.0 38.1 2.95E-07 7.87 67.5 60.0 94.0 38.1 8.31E-07 7.61 93 24.5 118.5 38.1 3.46E-07 7.63 115.5 42.5 161.0 38.1 6.80E-07 7.50 138.5 22.0 183.0 38.1 3.44E-07 7.49 163.5 25.0 208.0 38.1 3.60E-07 7.55 188 25.0 233.0 38.1 3.67E-07 7.63 211 23.0 256.0 38.1 3.60E-07 7.70 235 24.5 280.5 38.1 3.68E-07 7.49 259 27.5 308.0 38.1 4.13E-07 7.56 285 32.5 340.5 38.1 4.50E-07 7.57 304 24.0 364.5 38.1 4.55E-07 7.55 329 34.5 399.0 38.1 4.97E-07 7.55 381.5 72.5 471.5 38.1 4.97E-07 7.55 405.5 39.0 510.5 38.1 5.85E-07 7.52 428 41.0 551.5 38.1 6.56E-07 7.55 454.5 56.5 608.0 38.1 7.68E-07 7.58 478 52.0 660.0 38.1 7.97E-07 7.56 498.5 46.5 706.5 38.1 8.17E-07 7.54 528.5 63.5 770.0 38.1 7.62E-07 7.57 568.5 104.0 874.0 38.1 9.36E-07 7.60 597.5 83.5 957.5 38.1 1.04E-06 7.49 619.5 64.0 1021.5 38.1 1.05E-06 7.56 665 108.0 1129.5 38.1 8.55E-07 7.55 741.5 172.0 1301.5 38.1 8.09E-07 7.56 763.5 61.0 1362.5 38.1 9.98E-07 7.56 789.5 65.0 1427.5 38.1 9.00E-07 7.60 807 46.5 1474.0 38.1 9.57E-07 7.61 Hydraulic conductivity and pH data for Run £2 Elapsed Flow (mL) Cumulative Head k (cm/s) pH Time (h) Flow (mL) 41.5 2.0 2.0 38.1 1.73E-08 67.5 25.0 27.0 38.1 3.46E-07 7.80 93 7.0 34.0 38.1 9.88E-08 7.61 115.5 11.5 45.5 38.1 1.84E-07 7.45 138.5 8.5 54.0 38.1 1.33E-07 7.48 163.5 9.5 63.5 38.1 1.37E-07 7.45 188 9.0 72.5 38.1 1.32E-07 7.48 211 8.5 81.0 38.1 1.33E-07 7.53 235 9.5 90.5 38.1 1.43E-07 7.54 259 9.5 100.0 38.1 1.43E-07 7.58 285 10.5 110.5 38.1 1.45E-07 7.59 304 7.5 118.0 38.1 1.42E-07 7.55 329 10.5 128.5 38.1 1.51E-07 7.56 381.5 20.0 148.5 38.1 1.37E-07 7.57 405.5 8.0 156.5 38.1 1.20E-07 7.52 428 9.0 165.5 38.1 1.44E-07 7.55 454.5 10.0 175.5 38.1 1.36E-07 7.51 478 9.0 184.5 38.1 1.38E-07 7.49 498.5 9.0 193.5 38.1 1.58E-07 7.50 528.5 11.0 204.5 38.1 1.32E-07 7.49 568.5 23.5 228.0 38.1 2.12E-07 7.58 597.5 12.5 240.5 38.1 1.55E-07 7.57 619.5 7.5 248.0 38.1 1.23E-07 7.57 665 17.0 265.0 38.1 1.35E-07 7.52 741.5 30.0 295.0 38.1 1.41E-07 7.52 763.5 9.0 304.0 38.1 1.47E-07 7.55 789.5 10.0 314.0 38.1 1.38E-07 7.49 807 7.0 321.0 38.1 1.44E-07 7.56 Hydraulic conductivity and pH data for Run E3 Elapsed Flow (mL) Cumulative Head k (cm/s) pH Time (h) Flow (mL) 41.5 24.0 24.0 38.1 2.08E-07 7.79 67.5 44.5 68.5 38.1 6.16E-07 7.63 93 16.0 84.5 38.1 2.26E-07 7.51 115.5 13.0 97.5 38.1 2.08E-07 7.58 138.5 12.5 110.0 38.1 1.96E-07 7.55 163.5 14.0 124.0 38.1 2.02E-07 7.47 188 14.0 138.0 38.1 2.06E-07 7.45 211 13.5 151.5 38.1 2.11E-07 7.46 235 14.0 165.5 38.1 2.10E-07 7.51 259 17.0 182.5 38.1 2.55E-07 7.55 285 18.0 200.5 38.1 2.49E-07 7.53 304 13.5 214.0 38.1 2.56E-07 7.49 329 16.5 230.5 38.1 2.38E-07 7.48 381.5 35.0 265.5 38.1 2.40E-07 7.50 405.5 17.0 282.5 38.1 2.55E-07 7.56 428 15.0 297.5 38.1 2.40E-07 7.56 454.5 19.5 317.0 38.1 2.65E-07 7.49 478 17.5 334.5 38.1 2.68E-07 7.53 498.5 17.0 351.5 38.1 2.99E-07 7.52 528.5 21.0 372.5 38.1 2.52E-07 7.55 568.5 27.0 399.5 38.1 2.43E-07 7.50 597.5 19.5 419.0 38.1 2.42E-07 7.59 619.5 16.0 435.0 38.1 2.62E-07 7.49 665 32.5 467.5 38.1 2.57E-07 7.46 741.5 66.0 533.5 38.1 3.11E-07 7.45 763.5 17.5 551.0 38.1 2.86E-07 7.52 789.5 18.5 569.5 38.1 2.56E-07 7.52 807 12.5 582.0 38.1 2.57E-07 7.54 Hydraulic conductivity and pH data for Run E4 Elapsed Flow (mL) Cumulative Head k (cm/s) pH Time (h) Flow (mL) 23 22.1 22.1 29.1 4.53E-07 7.71 52 31.4 53.5 29.1 5.10E-07 7.54 94 44.5 98.0 29.1 5.00E-07 7.55 121 31.3 129.3 29.1 5.47E-07 7.56 166 52.5 181.8 29.1 5.50E-07 7.72 191 29.1 210.9 29.1 5.49E-07 7.71 212 24.8 235.7 29.1 5.57E-07 7.73 263 60.0 295.7 29.1 5.55E-07 7.50 334 84.7 380.4 29.1 5.62E-07 7.55 360 31.0 411.4 29.1 5.62E-07 7.53 390 36.5 447.9 29.1 5.74E-07 7.54 430 50.2 498.1 29.1 5.92E-07 7.55 503 95.2 593.3 29.1 6.15E-07 7.57 526 33.1 626.4 29.1 6.78E-07 7.53 550 35.0 661.4 29.1 6.88E-07 7.52 596 69.5 730.9 29.1 7.12E-07 7.54 673 125.7 856.6 29.1 7.70E-07 7.58 696 40.2 896.8 29.1 8.24E-07 7.59 746 93.0 989.8 29.1 8.77E-07 7.60 765 36.4 1026.2 29.1 9.03E-07 7.51 836 138.6 1164.8 29.1 9.20E-07 7.59 887 111.3 1276.1 29.1 1.03E-06 7.59 935 116.4 1392.5 27.7 1.20E-06 7.59 1002 145.3 1537.8 27.7 1.07E-06 7.61 1035 74.8 1612.6 27.7 1.12E-06 7.56 1103 149.5 1762.1 27.7 1.09E-06 7.57 1178 161.6 1923.7 27.7 1.07E-06 7.54 1231 118.3 2042.0 27.7 1.10E-06 7.58 1270 87.7 2129.7 27.7 1.11E-06 7.57 1341 152.2 2281.9 27.7 1.06E-06 7.56 Hydraulic conductivity and pH data for Run E5 Elapsed Flow (mL) Cumulative Head k (cm/s) PH Time (h) Flow (mL) 23 20.3 20.3 29.1 4.16E-07 7.65 52 28.4 48.7 29.1 4.62E-07 7.66 94 39.0 87.7 29.1 4.38E-07 7.68 121 27.2 114.9 29.1 4.75E-07 7.49 166 46.1 161.0 29.1 4.83E-07 7.48 191 24.7 185.7 29.1 4.66E-07 7.48 212 21.2 206.9 29.1 4.76E-07 7.55 263 51.0 257.9 29.1 4.71E-07 7.53 334 71.4 329.3 29.1 4.74E-07 7.59 360 23.8 353.1 29.1 4.32E-07 7.55 390 30.5 383.6 29.1 4.79E-07 7.51 430 41.5 425.1 29.1 4.89E-07 7.53 503 75.6 500.7 29.1 4.88E-07 7.58 526 25.9 526.6 29.1 5.31E-07 7.59 550 26.6 553.2 29.1 5.23E-07 7.48 596 50.7 603.9 29.1 5.20E-07 7.48 673 91.4 695.3 29.1 5.60E-07 7.51 696 28.7 724.0 29.1 5.88E-07 7.50 746 66.5 790.5 29.1 6.27E-07 7.49 765 27.0 817.5 29.1 6.70E-07 7.53 836 101.8 919.3 29.1 6.76E-07 7.50 887 80.4 999.7 29.1 7.43E-07 7.51 935 77.0 1076.7 27.7 7.94E-07 7.52 1002 107.8 1184.5 27.7 7.96E-07 7.53 1035 57.9 1242.4 27.7 8.69E-07 7.53 1103 117.4 1359.8 27.7 8.55E-07 7.51 1178 127.7 1487.5 27.7 8.43E-07 7.49 1231 94.1 1581.6 27.7 8.79E-07 7.53 1270 70.5 1652.1 27.7 8.95E-07 7.53 1341 122.0 1774.1 27.7 8.51E-07 7.50 Hydraulic conductivity and p H data for Run E6 Elapsed Flow (mL) Cumulative Head k (cm/s) p H Time (h) Flow (mL) 23 37.2 37.2 29.1 7.63E-07 7.75 52 49.8 87.0 29.1 8.10E-07 7.77 94 63.3 150.3 29.1 7.11E-07 7.69 121 41.8 192.1 29.1 7.30E-07 7.68 166 67.0 259.1 29.1 7.02E-07 7.65 191 34.7 293.8 29.1 6.54E-07 7.69 212 29.0 322.8 29.1 6.51E-07 7.67 263 69.4 392.2 29.1 6.42E-07 7.60 334 99.5 491.7 29.1 6.61E-07 7.55 360 35.7 527.4 29.1 6.47E-07 7.56 390 41.7 569.1 29.1 6.55E-07 7.57 430 57.0 626.1 29.1 6.72E-07 7.57 503 110.0 736.1 29.1 7.10E-07 7.52 526 38.6 774.7 29.1 7.91E-07 7.49 550 40.5 815.2 29.1 7.96E-07 7.47 596 76.8 892.0 29.1 7.87E-07 7.54 673 135.3 1027.3 29.1 8.28E-07 7.51 696 43.2 1070.5 29.1 8.85E-07 7.56 746 97.7 1168.2 29.1 9.21E-07 7.59 765 38.8 1207.0 29.1 9.63E-07 7.50 836 145.9 1352.9 29.1 9.69E-07 7.48 887 110.4 1463.3 29.1 1.02E-06 7.56 935 102.7 1566.0 27.7 1.06E-06 7.54 1002 138.2 1704.2 27.7 1.02E-06 7.57 1035 70.6 1774.8 27.7 1.06E-06 7.50 1103 140.5 1915.3 27.7 1.02E-06 7.48 1178 150.1 2065.4 27.7 9.91E-07 7.48 1231 109.0 2174.4 27.7 1.02E-06 7.49 1270 81.3 2255.7 27.7 1.03E-06 7.49 1341 141.0 2396.7 27.7 9.83E-07 7.51 Hydraulic conductivity, pH and [PCP] data for Run E7 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [PCP] Time (h) Flow (mL) (mg/L) 40.5 6.0 6.0 6.9 4.94E-08 0.00 65 13.0 19.0 6.9 1.77E-07 7.77 0.00 93 11.3 30.3 6.9 1.35E-07 7.76 0.00 117 10.4 40.7 6.9 1.44E-07 7.62 0.00 141 10.4 51.1 6.9 1.44E-07 7.61 0.00 185.5 17.1 68.2 6.9 1.28E-07 7.56 0.00 214.5 11.5 79.7 6.9 1.32E-07 7.49 0.00 234.5 8.5 88.2 6.9 1.40E-07 7.45 0.00 261 10.9 99.1 6.9 1.36E-07 7.48 0.00 280 8.1 107.2 6.9 1.41E-07 7.48 0.00 309 13.0 120.2 6.9 1.48E-07 7.48 0.00 359 19.0 139.2 6.9 1.25E-07 7.49 0.00 381 10.4 149.6 6.9 1.56E-07 7.47 0.00 403 10.2 159.8 6.9 1.53E-07 7.51 0.00 427.5 11.9 171.7 6.9 1.60E-07 7.50 0.00 450 11.1 182.8 6.9 1.63E-07 7.48 0.00 498 21.6 204.4 6.9 1.49E-07 7.50 0.00 524 13.3 217.7 6.9 1.69E-07 7.49 0.00 550 12.9 230.6 6.9 1.64E-07 7.49 0.00 575.5 12.6 243.2 6.9 1.63E-07 7.47 0.00 594.5 9.2 252.4 6.9 1.60E-07 7.46 0.00 619 11.4 263.8 6.9 1.54E-07 7.51 0.00 645.5 12.2 276.0 6.9 1.52E-07 7.53 0.00 693.5 19.4 295.4 6.9 1.33E-07 7.55 0.00 717.5 11.8 307.2 6.9 1.62E-07 7.51 0.00 742.5 12.0 319.2 6.9 1.58E-07 7.52 0.00 768.5 13.0 332.2 6.9 1.65E-07 7.54 0.00 787 10.5 342.7 6.9 1.87E-07 7.55 0.00 861.5 44.9 387.6 6.9 1.99E-07 7.49 0.00 887 13.2 400.8 6.9 1.71E-07 7.53 0.00 913 14.3 415.1 6.9 1.82E-07 7.58 0.00 932.5 11.3 426.4 6.9 1.91E-07 7.56 0.00 984 32.6 459.0 6.9 2.09E-07 7.56 0.00 1030 25.2 484.2 6.9 1.81E-07 7.57 0.00 1054 15.4 499.6 6.9 2.12E-07 7.54 0.00 1077 13.9 513.5 6.9 1.99E-07 7.56 0.00 1101.5 11.1 524.6 7.2 1.45E-07 7.55 0.00 1121.5 13.4 538.0 7.2 2.14E-07 7.55 0.00 1217.5 39.6 577.6 7.2 1.32E-07 7.55 0.00 Hydraulic conductivity, pH and [PCP] data for Run E8 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [PCP] Time (h) Flow (mL) (mg/L) 40.5 13.0 13.0 6.9 4.33E-06 7.95 0.00 65 20.0 33.0 6.9 6.67E-06 7.65 0.00 93 12.5 45.5 6.9 4.17E-06 7.54 0.00 117 10.3 55.8 6.9 3.43E-06 7.60 0.00 141 10.5 66.3 6.9 3.50E-06 7.59 0.00 185.5 19.6 85.9 6.9 6.53E-06 7.58 0.00 214.5 12.5 98.4 6.9 4.17E-06 7.61 0.00 234.5 9.5 107.9 6.9 3.14E-06 7.61 0.00 261 12.2 120.1 6.9 4.03E-06 7.63 0.00 280 8.9 129.0 6.9 2.94E-06 7.59 0.00 309 14.1 143.1 6.9 4.65E-06 7.58 0.00 359 23.4 166.5 6.9 7.72E-06 7.62 0.00 381 11.9 178.4 6.9 ' 3.93E-06 7.57 0.00 403 11.2 189.6 6.9 3.70E-06 7.60 0.00 427.5 10.1 199.7 6.9 3.33E-06 7.60 0.00 450 10.3 210.0 6.9 3.40E-06 7.59 0.00 498 20.6 230.6 6.9 6.80E-06 7.59 0.00 524 13.5 244.1 6.9 4.46E-06 7.57 0.00 550 12.6 256.7 6.9 4.16E-06 7.64 0.00 575.5 13.0 269.7 6.9 4.29E-06 7.62 0.00 594.5 9.4 279.1 6.9 3.10E-06 7.64 0.00 619 12.0 291.1 6.9 3.96E-06 7.64 0.00 645.5 12.4 303.5 6.9 4.09E-06 7.59 0.00 693.5 24.5 328.0 6.9 8.09E-06 7.58 0.00 717.5 12.1 340.1 6.9 3.99E-06 7.55 0.00 742.5 12.5 352.6 6.9 4.13E-06 7.57 0.00 768.5 12.8 365.4 6.9 4.22E-06 7.58 0.00 787 10.0 375.4 6.9 3.30E-06 7.58 0.00 861.5 27.7 403.1 6.9 9.14E-06 7.59 0.00 887 12.6 415.7 6.9 4.16E-06 7.60 0.00 913 13.4 429.1 6.9 4.42E-06 7.56 0.00 932.5 10.4 439.5 6.9 3.43E-06 7.58 0.00 984 21.3 460.8 6.9 7.03E-06 7.57 0.00 1030 21.6 482.4 6.9 7.13E-06 7.59 0.00 1054 14.1 496.5 6.9 4.65E-06 7.62 0.00 1077 12.4 508.9 6.9 4.09E-06 7.62 0.00 1101.5 13.5 522.4 7.2 4.31E-06 7.63 0.00 1121.5 11.9 534.3 7.2 3.80E-06 7.58 0.00 1217.5 35.8 570.1 7.2 1.14E-05 7.63 0.00 Hydraulic conductivity, pH and [PCP] data for Run E9 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [PCP] Time (h) Flow (mL) (mg/L) 40.5 17.0 17.0 6.9 1.40E-07 8.10 0.00 65 25.5 42.5 6.9 3.47E-07 7.68 0.00 93 12.9 55.4 6.9 1.54E-07 7.67 0.00 117 10.8 66.2 6.9 1.50E-07 7.70 0.00 141 11.4 77.6 6.9 1.58E-07 7.72 0.00 185.5 21.4 99.0 6.9 1.60E-07 7.50 0.00 214.5 13.6 112.6 6.9 1.56E-07 7.56 0.00 234.5 9.7 122.3 6.9 1.60E-07 7.55 0.00 261 12.6 134.9 6.9 1.57E-07 7.58 0.00 280 9.5 144.4 6.9 1.65E-07 7.49 0.00 309 15.4 159.8 6.9 1.75E-07 7.48 0.00 359 27.0 186.8 6.9 1.78E-07 7.47 0.00 381 12.5 199.3 6.9 1.88E-07 7.54 0.00 403 12.7 212.0 6.9 1.91E-07 7.54 0.00 427.5 13.9 225.9 6.9 1.87E-07 7.55 0.00 450 13.1 239.0 6.9 1.92E-07 7.57 0.00 498 28.7 267.7 6.9 1.97E-07 7.56 0.00 524 15.1 282.8 6.9 1.92E-07 7.57 0.00 550 15.1 297.9 6.9 1.92E-07 .7.56 0.00 575.5 14.6 312.5 6.9 1.89E-07 7.53 0.00 594.5 10.7 323.2 6.9 1.86E-07 7.55 0.00 619 14.2 337.4 6.9 1.91E-07 7.51 0.00 645.5 16.0 353.4 6.9 1.99E-07 7.49 0.00 693.5 31.3 384.7 6.9 2.15E-07 7.59 0.00 717.5 15.0 399.7 6.9 2.06E-07 7.57 0.00 742.5 16.4 416.1 6.9 2.16E-07 7.56 0.00 768.5 17.3 433.4 6.9 2.20E-07 7.52 0.00 787 11.8 445.2 6.9 2.10E-07 7.52 0.00 861.5 53.2 498.4 6.9 2.36E-07 7.52 0.00 887 18.6 517.0 6.9 2.41E-07 7.53 0.00 913 18.0 535.0 6.9 2.28E-07 7.54 0.00 932.5 16.6 551.6 6.9 2.81E-07 7.52 0.00 984 42.4 594.0 6.9 2.72E-07 7.55 0.00 1030 36.6 630.6 6.9 2.63E-07 7.49 0.00 . 1054 20.4 651.0 6.9 2.81E-07 7.50 0.00 1077 18.8 669.8 6.9 2.70E-07 7.51 0.00 1101.5 22.1 691.9 7.2 2.88E-07 7.58 0.00 1121.5 18.5 710.4 7.2 2.95E-07 7.57 0.00 1217.5 83.1 793.5 7.2 2.76E-07 7.56 0.00 Hydraulic conductivity, pH and [PCP] data for Run E10 Elapsed Time (h) Flow (mL) Cumulative Flow (mL) Head k (cm/s) pH [PCP] (mg/L) 21 182.9 182.9 13.6 1.46E-06 7.62 0.00 68 169.9 352.8 6.5 1.28E-06 7.53 0.00 73 22.5 375.3 6.5 1.59E-06 7.40 0.00 93 49.5 424.8 4.6 1.21E-06 7.45 0.00 94 2.6 427.4 4.6 1.29E-06 0.00 95 2.5 429.9 4.6 1.24E-06 0.00 97 3.1 433.0 4.6 1.18E-06 7.46 0.00 98 2.3 435.3 4.6 1.20E-06 0.00 " 99 2.6 437.9 4.6 1.29E-06 7.48 0.00 101 6.8 444.7 4.6 1.22E-06 7.43 0.00 118 44.3 489.0 4.6 1.28E-06 7.44 0.00 143 71.3 560.3 4.6 1.44E-06 7.49 0.00 165 72.3 632.6 4.6 1.59E-06 7.51 0.03 192 86.6 719.2 4.6 1.62E-06 7.52 0.21 219 101.1 820.3 4.6 1.85E-06 • 7.52 0.21 238 83.2 903.5 4.6 2.17E-06 7.50 1.68 243 23.4 926.9 4.6 2.32E-06 7.49 2.72 261 92.2 1019.1 4.6 2.47E-06 7.48 2.72 265 18.6 1037.7 4.6 2.63E-06 7.52 2.72 286 46.3 1084.0 4.6 1.09E-06 7.51 7.56 Hydraulic conductivity, pH and [PCP] data for Run E l l Elapsed Flow (mL) Cumulative Head k (cm/s) pH [PCP] Time (h) Flow (mL) (mg/L) 21 211.2 211.2 13.6 1.69E-06 7.59 0.00 68 233 444.2 6.5 1.75E-06 7.47 0.00 73 31.5 475.7 6.5 2.23E-06 7.51 0.00 93 85.4 561.1 4.6 2.08E-06 7.46 0.00 94 3.8 564.9 4.6 2.05E-06 0.00 95 4.8 569.7 4.6 2.30E-06 7.44 0.00 97 5.7 575.4 4.6 2.29E-06 0.00 98 4.3 579.7 4.6 2.28E-06 7.48 0.00 99 4.8 584.5 4.6 2.34E-06 7.48 0.00 101 12.9 597.4 4.6 2.29E-06 7.49 0.03 118 30.5 627.9 4.6 8.79E-07 7.53 0.07 143 122.6 750.5 4.6 2.48E-06 7.51 0.36 165 130.7 881.2 4.6 2.88E-06 7.53 1.62 192 195.3 1076.5 4.6 3.65E-06 7.52 4.34 219 236.1 1312.6 4.6 4.33E-06 • 7.47 5.07 238 187.4 1500.0 4.6 4.88E-06 7.51 5.79 243 52.5 1552.5 4.6 5.20E-06 7.56 5.97 261 193.9 1746.4 4.6 5.19E-06 7.57 6.14 265 39.7 1786.1 4.6 5.61E-06 7.59 0.00 286 141.1 1927.2 4.6 3.33E-06 7.55 0.00 Hydraulic conductivity, pH and [PCP] data for Run E12 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [PCP] Time (h) Flow (mL) (mg/L) 21 74.1 74.1 13.6 5.92E-07 7.47 0.00 68 230.9 305.0 6.5 1.74E-06 7.52 0.00 73 25.6 330.6 6.5 1.81E-06 7.53 0.00 93 65.9 396.5 4.6 1.60E-06 7.49 0.00 94 2.5 399.0 4.6 1.49E-06 0.00 95 3.3 402.3 4.6 1.58E-06 0.00 97 4.2 406.5 4.6 1.58E-06 7.53 0.00 98 3 409.5 4.6 1.62E-06 0.00 99 3.3 412.8 4.6 1.58E-06 7.56 0.00 101 8.9 421.7 4.6 1.55E-06 7.57 0.00 118 54.3 476.0 4.6 1.56E-06 7.58 0.00 143 78.2 554.2 4.6 1.58E-06 7.51 0.00 165 73.3 627.5 4.6 1.58E-06 7.53 0.00 192 88 715.5 4.6 1.64E-06 7.54 0.00 219 95.1 810.6 4.6 1.74E-06 7.55 0.00 238 69.6 880.2 4.6 1.81E-06 7.49 0.30 243 20.3 900.5 4.6 2.01E-06 7.54 1.46 261 87.2 987.7 4.6 2.33E-06 7.60 0.00 265 18.7 1006.4 4.6 2.64E-06 7.62 0.00 286 117.1 1123.5 4.6 2.76E-06 7.58 0.00 Hydraulic conductivity, pH and [NP] data for Run E13 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [NP] Time (h) Flow (mL) (mg/L) 21 60.2 60.2 31.8 1.23E-06 7.80 0.00 48 32.6 92.8 31.8 5.30E-07 7.78 0.00 73 84.7 177.5 31.8 1.43E-06 7.71 0.00 94 64.5 242.0 31.8 1.32E-06 7.60 0.00 117 67.7 309.7 31.8 1.27E-06 7.64 0.00 146 97.0 406.7 31.8 1.44E-06 7.55 0.00 166 98.0 504.7 31.8 2.16E-06 7.52 0.80 194 81.1 585.8 31.8 1.25E-06 7.58 2.70 214 194.3 780.1 31.8 4.08E-06 7.61 4.10 262 650.0 1430.1 31.8 5.83E-06 7.58 2.50 291 540.0 1970.1 31.8 8.02E-06 7.57 2.40 Hydraulic conductivity, pH and [NP] data for Run E14 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [NP] Time (h) Flow (mL) (mg/L) 21 30.0 30.0 31.8 6.15E-07 7.75 0.00 48 38.6 68.6 31.8 6.27E-07 7.70 0.00 73 41.1 109.7 31.8 6.94E-07 7.52 0.00 94 36.0 145.7 31.8 7.38E-07 7.51 0.00 117 38.9 184.6 31.8 7.28E-07 7.59 0.00 146 46.0 230.6 31.8 6.83E-07 7.58 0.00 166 31.8 262.4 31.8 7.02E-07 7.55 0.00 194 45.2 307.6 31.8 6.95E-07 7.50 0.00 214 31.1 338.7 31.8 6.53E-07 7.49 0.00 262 80.8 419.5 31.8 7.25E-07 7.53 0.00 291 50.0 469.5 31.8 7.42E-07 7.59 0.00 312 37.2 506.7 31.8 7.81E-07 7.60 0.00 337 45.4 552.1 31.8 7.82E-07 7.59 0.00 357 37.9 590.0 31.8 7.96E-07 7.55 0.00 381 47.2 637.2 31.8 8.47E-07 7.56 0.00 405 49.6 686.8 31.8 8.90E-07 7.57 0.29 456 119.5 806.3 31.8 1.01E-06 7.55 0.74 479 53.6 859.9 31.8 1.00E-06 7.55 1.93 509 115.7 975.6 31.8 1.69E-06 7.55 0.96 iydraulic conductivity, pH and [NP] data for Run E15 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [NP] Time (h) Flow (mL) (mg/L) 21 31.7 31.7 31.8 6.50E-07 7.72 0.00 48 43.9 75.6 31.8 7.13E-07 7.70 0.00 73 44.4 120.0 31.8 7.49E-07 7.65 0.00 94 37.0 157.0 31.8 7.58E-07 7.62 0.00 117 40.0 197.0 31.8 7.49E-07 7.63 0.00 146 48.1 245.1 31.8 7.14E-07 7.63 0.00 166 32.6 277.7 31.8 7.20E-07 7.65 0.00 194 45.8 323.5 31.8 7.04E-07 7.62 0.00 214 34.1 357.6 31.8 7.16E-07 7.55 0.00 262 80.4 438.0 31.8 7.21E-07 7.51 0.00 291 48.2 486.2 31.8 7.15E-07 7.49 0.00 312 37.0 523.2 31.8 7.77E-07 7.52 0.00 337 45.7 568.9 31.8 7.87E-07 7.51 0.01 357 37.8 606.7 31.8 7.94E-07 7.53 0.00 381 47.6 654.3 31.8 8.54E-07 7.49 0.08 405 53.8 708.1 31.8 9.65E-07 '7.48 1.02 456 146.3 854.4 31.8 1.23E-06 7.51 2.39 479 100.4 954.8 31.8 1.88E-06 7.55 3.45 509 161.9 1116.7 31.8 2.36E-06 7.53 1.92 Hydraulic conductivity, pH and [NP] data for Run E16 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [NP] Time (h) Flow (mL) (mg/L) 17 13.6 13.6 30.5 3.71E-07 7.68 0.13 46 24.4 38.0 30.5 4.67E-07 7.69 0.06 67 27.2 65.2 29.1 4.35E-07 7.74 0.05 137 19.9 85.1 30.5 4.37E-07 7.72 0.03 162 68.8 153.9 30.5 4.39E-07 7.65 0.03 188 24.2 178.1 30.5 4.44E-07 7.55 0.00 233 24.0 202.1 29.1 4.35E-07 7.50 0.00 332 39.4 241.5 27.7 4.33E-07 7.52 0.00 404 97.4 338.9 29.1 4.64E-07 7.53 0.00 458 33.5 372.4 29.1 2.19E-07 7.56 0.00 480 74.4 446.8 29.1 6.44E-07 7.54 0.00 558 45.9 492.7 29.1 1.01E-06 7.56 0.30 609 93.4 586.1 29.1 5.61E-07 7.56 3.93 660 250.0 836.1 29.1 2.31E-06 7.51 4.69 Hydraulic conductivity, pH and [NP] data for Run E17 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [NP] Time (h) Flow (mL) (mg/L) 17 12.5 12.5 30.5 3.41E-07 7.81 0.16 46 23.8 36.3 30.5 4.56E-07 7.82 0.06 67 25.7 62.0 29.1 4.11E-07 7.63 0.03 137 18.6 80.6 30.5 4.08E-07 7.62 0.02 162 69.9 150.5 30.5 4.46E-07 7.65 0.02 188 26.8 177.3 30.5 4.92E-07 7.67 0.00 233 27.1 204.4 29.1 4.91E-07 7.68 0.00 332 45.2 249.6 27.7 4.97E-07 7.59 0.00 404 108.5 358.1 29.1 5.17E-07 7.58 0.00 458 17.5 375.6 29.1 1.15E-07 7.62 0.00 480 250.0 625.6 29.1 . 2.16E-06 7.63 4.12 Tydraulic conductivity, pH and [NP] data for Run E18 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [NP] Time (h) Flow (mL) (mg/L) 17 7.1 7.1 30.5 1.94E-07 7.79 0.52 46 20.1 27.2 30.5 3.85E-07 7.83 0.14 67 21.4 48.6 29.1 3.42E-07 7.61 0.11 137 14.7 63.3 30.5 3.23E-07 7.55 0.08 162 52.8 116.1 30.5 3.37E-07 7.50 0.06 188 21.2 137.3 30.5 3.89E-07 7.49 0.06 233 21.8 159.1 29.1 3.95E-07 7.47 0.00 332 38.2 197.3 27.7 4.20E-07 7.51 0.00 404 97.2 294.5 29.1 4.63E-07 7.53 0.00 458 125.6 420.1 29.1 8.22E-07 7.52 1.68 480 250.0 670.1 29.1 2.16E-06 7.52 3.68 Hydraulic conductivity, pH and [NP] data for Run E19 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [NP] Time (h) Flow (mL) (mg/L) 24 21.1 21.1 20.8 5.80E-07 7.78 0.00 76 34.5 55.6 20.8 4.42E-07 7.78 0.00 100 14.7 70.3 20.8 4.04E-07 7.77 0.00 125 15.3 85.6 20.8 4.04E-07 7.64 0.00 172 30.4 116.0 20.8 4.27E-07 7.68 0.00 195 15.4 131.4 20.8 4.42E-07 7.54 0.00 219 15.6 147.0 20.8 4.29E-07 7.53 0.00 243 16.0 163.0 20.8 4.31E-07 7.55 0.00 263 14.8 177.8 23.5 4.31E-07 7.52 0.00 316 40.4 218.2 23.5 4.48E-07 7.49 0.00 340 18.4 236.6 23.5 4.46E-07 7.52 0.00 363 17.4 254.0 23.5 4.41E-07 7.53 0.00 386 17.6 271.6 24.9 4.21E-07 7.54 0.00 412 20.1 291.7 24.9 4.25E-07 7.49 0.00 432 16.0 307.7 24.9 4.40E-07 7.48 0.00 509 63.3 371.0 24.9 4.52E-07 7.52 0.00 555 40.9 411.9 24.9 4.89E-07 7.55 0.00 579 22.9 434.8 24.9 5.25E-07 7.49 0.00 600 19.4 454.2 24.9 5.08E-07 7.56 0.00 629 27.9 482.1 24.9 5.29E-07 7.50 0.00 673 42.0 524.1 24.9 5.25E-07 7.51 0.00 700 27.4 551.5 24.9 5.58E-07 7.57 0.00 720 20.8 572.3 24.9 5.72E-07 7.55 0.00 749 30.4 602.7 24.9 5.77E-07 7.49 0.00 767 19.5 622.2 24.9 5.96E-07 7.47 0.00 796 32.4 654.6 24.9 6.14E-07 7.52 0.06 844 54.9 709.5 24.9 6.29E-07 7.53 0.11 867 28.1 737.6 24.9 6.72E-07 7.52 0.20 888 27.3 764.9 24.9 7.15E-07 7.51 0.30 987 143.4 908.3 24.9 7.97E-07 7.53 0.91 1010 40.2 948.5 24.9 9.61E-07 7.55 1.25 1059 92.6 1041.1 24.9 1.04E-06 7.54 1.68 Hydraulic conductivity, pH and [NP] data for Run E20 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [NP] Time (h) Flow (mL) (mg/L) 24 21.7 21.7 20.8 5.97E-07 7.82 0.00 76 39.8 61.5 20.8 5.10E-07 7.81 0.00 100 19.3 80.8 20.8 5.31E-07 7.63 0.00 125 21.0 101.8 20.8 5.54E-07 7.64 0.00 172 43.2 145.0 20.8 6.07E-07 7.62 0.00 195 22.5 167.5 20.8 6.46E-07 7.63 0.00 219 22.3 189.8 20.8 6.13E-07 7.65 0.00 243 22.9 212.7 20.8 6.17E-07 7.55 0.00 263 21.7 234.4 23.5 6.32E-07 7.58 0.00 316 59.2 293.6 23.5 6.57E-07 7.60 0.00 340 27.5 321.1 23.5 6.67E-07 7.61 0.00 363 26.0 347.1 23.5 6.58E-07 7.59 0.00 386 26.2 373.3 24.9 6.27E-07 7.58 0.00 412 29.9 403.2 24.9 6.33E-07 7.52 . 0.00 432 24.7 427.9 24.9 6.79E-07 7.55 0.00 509 98.4 526.3 24.9 7.03E-07 7.58 0.00 555 69.5 595.8 24.9 8.31E-07 7.59 0.00 579 41.1 636.9 24.9 9.42E-07 7.55 0.13 600 37.1 674.0 24.9 9.72E-07 7.54 0.30 629 64.8 738.8 24.9 1.23E-06 7.53 0.85 673 149.4 888.2 24.9 1.87E-06 7.56 1.90 700 112.2 1000.4 24.9 2.29E-06 7.57 2.18 720 96.7 1097.1 24.9 2.66E-06 7.50 2.98 749 155.6 1252.7 24.9 2.95E-06 7.51 3.21 767 104.4 1357.1 24.9 3.19E-06 7.52 3.50 796 177.0 1534.1 24.9 3.36E-06 7.55 3.71 844 300.0 1834.1 24.9 3.44E-06 7.54 0.27 867 155.3 1989.4 24.9 3.71E-06 7.53 0.81 888 159.4 2148.8 24.9 4.17E-06 7.51 0.84 987 650.0 2798.8 24.9 3.61E-06 7.56 1.05 1010 164.2 2963.0 24.9 3.93E-06 7.57 0.92 1059 300.0 3263.0 24.9 3.37E-06 7.56 0.86 Hydraulic conductivity, pH and [NP] data for Run E21 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [NP] Time (h) Flow (mL) (mg/L) 24 23.0 23.0 20.8 6.33E-07 7.77 0.00 76 41.3 64.3 20.8 5.29E-07 7.69 0.00 100 20.1 84.4 20.8 5.53E-07 7.67 0.00 125 21.4 105.8 20.8 5.65E-07 7.66 0.00 172 44.3 150.1 20.8 6.22E-07 7.69 0.00 195 22.4 172.5 20.8 6.43E-07 7.70 0.00 219 22.1 194.6 20.8 6.08E-07 7.68 0.00 243 22.3 216.9 20.8 6.01E-07 7.61 0.00 263 21.3 238.2 23.5 6.20E-07 7.69 0.00 316 54.7 292.9 23.5 6.07E-07 7.70 0.00 340 24.8 317.7 23.5 6.02E-07 7.71 0.00 363 23.4 341.1 23.5 5.92E-07 7.72 0.00 386 23.2 364.3 24.9 5.55E-07 7.69 0.00 412 26.8 391.1 24.9 5.67E-07 7.68 0.00 432 21.2 412.3 24.9 5.83E-07 7.70 0.00 509 87.0 499.3 24.9 6.21E-07 7.63 0.00 555 65.1 564.4 24.9 7.78E-07 7.64 0.21 579 47.2 611.6 24.9 1.08E-06 7.59 1.10 600 54.0 665.6 24.9 1.41E-06 7.58 1.97 629 90.9 756.5 24.9 1.72E-06 7.60 2.24 673 163.3 919.8 24.9 2.04E-06 7.61 2.79 700 113.3 1033.1 24.9 2.31E-06 7.57 3.06 720 81.3 1114.4 24.9 2.24E-06 7.58 3.44 749 86.2 1200.6 24.9 1.63E-06 7.55 3.17 767 55.6 1256.2 24.9 1.70E-06 7.60 3.60 796 113.5 1369.7 24.9 2.15E-06 7.61 3.58 844 150.0 1519.7 24.9 1.72E-06 7.55 0.52 867 74.3 1594.0 24.9 1.78E-06 7.59 0.33 888 66.3 1660.3 24.9 1.74E-06 7.56 0.54 987 340.0 2000.3 24.9 1.89E-06 7.56 0.75 1010 101.2 2101.5 24.9 2.42E-06 7.57 0.64 1059 175.0 2276.5 24.9 1.96E-06 7.55 0.50 Hydraulic conductivity, pH and [TL] data for Run E22 Elapsed Time (h) Flow (mL) Cumulative Flow (mL) Head k (cm/s) pH [TL] (mg/L) 25 18.5 18.5 33.2 3.05E-07 7.85 0.00 47 16.7 35.2 33.2 3.13E-07 7.79 0.00 73 18.2 53.4 33.2 2.89E-07 7.75 0.00 98 17.5 70.9 33.2 2.89E-07 7.76 0.00 119 14.9 85.8 33.2 2.93E-07 7.62 0.00 168 37.2 123.0 33.2 3.13E-07 7.54 0.00 192 20.0 143.0 33.2 3.44E-07 7.53 0.00 219 23.2 166.2 33.2 3.54E-07 7.47 0.00 244 21.7 187.9 33.2 3.58E-07 7.50 0.00 266 19.6 207.5 33.2 3.68E-07 7.51 0.00 313 43.0 250.5 33.2 3.77E-07 7.52 0.00 335 22.9 273.4 33.2 4.29E-07 7.49 0.00 362 30.2 303.6 33.2 4.61E-07 7.53 0.00 433 91.3 394.9 33.2 5.30E-07 7.50 0.00 485 95.6 490.5 33.2 7.58E-07 7.52 0.00 507 96.8 587.3 31.8 1.89E-06 7.54 0.00 532 245.5 832.8 31.8 4.23E-06 7.51 0.00 547 184.3 1017.1 31.8 5.29E-06 7.52 0.00-556 112.3 1129.4 31.8 5.37E-06 7.52 0.00 Hydraulic conductivity, pH and [TL] data for Run E23 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [TL] Time (h) Flow (mL) (mg/L) 25 14.8 14.8 33.2 2.44E-07 7.76 0.00 47 14.8 29.6 33.2 2.78E-07 7.65 0.00 73 16.2 45.8 33.2 2.57E-07 7.65 0.00 98 15.5 61.3 33.2 2.56E-07 7.61 0.00 119 13.1 74.4 33.2 2.57E-07 7.63 0.00 168 31.7 106.1 33.2 2.67E-07 7.54 0.00 192 17.0 123.1 33.2 2.92E-07 7.53 0.00 219 19.0 142.1 33.2 2.90E-07 7.49 0.00 244 17.7 159.8 33.2 2.92E-07 7.52 0.00 266 16.1 175.9 33.2 3.02E-07 7.53 0.00 313 33.6 209.5 33.2 2.95E-07 7.50 0.00 335 16.4 225.9 33.2 3.08E-07 7.51 0.00 362 20.4 246.3 33.2 3.12E-07 7.55 0.00 433 55.0 301.3 33.2 3.20E-07 7.48 0.00 485 42.7 344.0 33.2 3.39E-07 7.50 0.00 507 19.3 363.3 31.8 3.78E-07 7.53 0.00 532 22.1 385.4 31.8 3.81E-07 7.50 0.00 547 13.3 398.7 31.8 3.82E-07 7.51 0.00 603 49.2 447.9 31.8 3.78E-07 7.54 0.00 627 22.9 470.8 31.8 4.11E-07 7.49 0.00 672 43.6 514.4 31.8 4.17E-07 7.48 0.00 693 22.1 536.5 31.8 4.53E-07 7.52 0.00 748 100.9 637.4 31.8 7.90E-07 7.50 0.00 771 82.3 719.7 31.8 1.54E-06 7.55 0.00 815 250.0 969.7 31.8 2.45E-06 7.56 0.00 840 219.2 1188.9 31.8 3.77E-06 7.57 0.00 Hydraulic conductivity, pH and [TL] data for Run E24 Elapsed Flow (mL) Cumulative Head k (cm/s) pH |TL] Time (h) Flow (mL) (mg/L) 25 19.7 19.7 33.2 3.25E-07 7.77 0.00 47 16.9 36.6 33.2 3.17E-07 7.71 0.00 73 19.1 55.7 33.2 3.03E-07 7.60 0.00 98 18.2 73.9 33.2 3.00E-07 7.59 0.00 119 15.6 89.5 33.2 3.06E-07 7.65 0.00 168 38.9 128.4 33.2 3.27E-07 7.56 0.00 192 21.0 149.4 33.2 3.61E-07 7.50 0.00 219 23.9 173.3 33.2 3.65E-07 7.48 0.00 244 23.6 196.9 33.2 3.89E-07 7.47 0.00 266 22.8 219.7 33.2 4.28E-07 7.31 0.00 313 51.3 271.0 33.2 4.50E-07 7.45 0.00 335 25.8 296.8 33.2 4.84E-07 7.51 0.00 362 32.4 329.2 33.2 4.95E-07 7.52 0.00 433 102.1 431.3 33.2 5.93E-07 7.56 0.00 485 243.6 674.9 33.2 1.93E-06 7.53 0.00 507 177.6 852.5 31.8 3.47E-06 7.54 0.00 532 247.8 1100.3 31.8 4.27E-06 7.48 0.00 547 167.7 1268.0 31.8 4.81E-06 7.49 0.00 556 104.9 1372.9 31.8 5.02E-06 7.51 0.00 Hydraulic conductivity, pH and [MEK] data for Run E25 Elapsed Time (h) Flow (mL) Cumulative Flow (mL) Head k (cm/s) pH [MEK] (mg/L) 15 11.1 11.1 27.7 3.66E-07 8.11 0.00 42 26.6 37.7 27.7 4.88E-07 7.58 0.00 68 24.0 61.7 27.7 4.57E-07 7.65 0.00 91 20.9 82.6 27.7 4.50E-07 7.68 0.19 116 22.4 105.0 27.7 4.44E-07 7.49 0.27 211 88.8 193.8 29.1 4.41E-07 7.45 0.00 238 25.5 219.3 29.1 4.45E-07 7.55 0.00 258 17.5 236.8 29.1 4.13E-07 7.53 0.00 281 21.8 258.6 29.1 4.47E-07 7.52 0.00 307 23.4 282.0 29.1 4.24E-07 7.55 0.00 332 24.9 306.9 29.1 4.70E-07 7.49 0.00 405 83.8 390.7 29.1 5.41E-07 7.50 0.00 427 69.8 460.5 29.1 1.50E-06 7.51 2.98 451 90.8 551.3 29.1 1.78E-06 7.47 2.50 476 90.4 641.7 29.1 1.70E-06 7.58 2.63 500 91.7 733.4 29.1 1.80E-06 7.59 2.46 520 80.7 814.1 29.1 1.90E-06 7.60 2.68 549 116.4 930.5 29.1 1.89E-06 7.57 2.33 571 93.8 1024.3 29.1 2.01E-06 7.58 2.97 595 92.8 1117.1 29.1 1.82E-06 7.59 3.33 619 90.6 1207.7 29.1 1.78E-06 7.55 2.29 643 83.4 1291.1 29.1 1.64E-06 7.53 1.92 665 76.3 1367.4 29.1 1.64E-06 7.54 1.06 692 94.4 1461.8 29.1 1.65E-06 7.54 1.41 736 147.3 1609.1 29.1 1.58E-06 7.54 1.38 765 96.3 1705.4 29.1 1.57E-06 7.56 1.98 786 71.1 1776.5 29.1 1.60E-06 7.57 0.00 815 94.4 1870.9 29.1 1.53E-06 7.51 1.28 836 69.9 1940.8 29.1 1.57E-06 7.50 0.68 863 90.5 2031.3 29.1 1.58E-06 7.53 1.53 905 132.7 2164.0 29.1 1.49E-06 7.52 0.00 930 75.8 2239.8 29.1 1.43E-06 7.51 0.00 955 73.1 2312.9 29.1 1.38E-06 7.53 0.00 977 58.4 2371.3 29.1 1.25E-06 7.53 0.00 1004 57.2 2428.5 29.1 9.99E-07 7.59 0.00 1030 48.1 2476.6 29.1 8.72E-07 7.58 0.00 1075 95.8 2572.4 29.1 1.00E-06 7.49 0.00 1100 51.7 2624.1 29.1 9.75E-07 7.47 0.00 1128 58.3 2682.4 29.1 9.82E-07 7.48 0.00 1148 44.8 2727.2 29.1 1.06E-06 7.53 0.00 1173 54.0 2781.2 29.1 1.02E-06 7.54 0.00 1246 139.5 2920.7 29.1 9.01E-07 7.54 0.00 1271 42.1 2962.8 29.1 7.94E-07 7.55 0.00 1290 31.6 2994.4 29.1 7.84E-07 7.53 0.00 1316 45.5 3039.9 29.1 8.25E-07 7.52 0.00 1341 42.7 3082.6 29.1 8.05E-07 7.53 0.00 1370 50.8 3133.4 29.1 8.26E-07 7.54 0.00 1411 72.2 3205.6 29.1 8.30E-07 7.56 0.00 1431 34.6 3240.2 29.1 8.16E-07 7.55 0.00 Hydraulic conductivity, pH and [MEK] data for Run E26 Elapsed Flow (mL) Cumulative Head k (cm/s) PH [MEK] Time (h) Flow (mL) (mg/L) 15 7.3 7.3 27.7 2.41E-07 8.02 0.00 42 24.5 31.8 27.7 4.49E-07 7.66 0.00 68 21.6 53.4 27.7 4.11E-07 7.68 0.00 91 18.3 71.7 27.7 3.94E-07 7;58 0.00 116 19.4 91.1 27.7 3.84E-07 7.49 0.00 211 77.1 168.2 29.1 3.83E-07 7.53 0.00 238 24.3 192.5 29.1 4.24E-07 7.45 0.00 258 18.1 210.6 29.1 4.27E-07 7.46 0.00 281 20.9 231.5 29.1 4.28E-07 7.48 0.00 307 21.6 253.1 29.1 3.92E-07 7.51 0.00 332 21.1 274.2 29.1 3.98E-07 7.51 0.00 405 58.3 332.5 29.1 3.77E-07 7.48 0.00 427 18.2 350.7 29.1 3.90E-07 7.49 0.00 451 20.7 371.4 29.1 4.07E-07 7.55 0.00 476 21.4 392.8 29.1 4.04E-07 7.54 0.00 500 21.2 414.0 29.1 4.16E-07 7.53 0.00 520 17.7 431.7 29.1 4.17E-07 7.53 0.00 549 23.5 455.2 29.1 3.82E-07 7.53 0.00 571 18.6 473.8 29.1 3.99E-07 7.57 0.00 595 19.8 493.6 29.1 3.89E-07 7.49 0.00 619 20.4 514.0 29.1 4.01E-07 7.47 0.00 643 19.2 533.2 29.1 3.77E-07 7.48 0.00 665 18.8 552.0 29.1 4.03E-07 7.47 0.00 692 23.1 575.1 29.1 4.03E-07 7.45 0.00 736 36.4 611.5 29.1 3.90E-07 7.43 0.00 765 21.5 633.0 29.1 3.50E-07 7.46 0.00 786 16.2 649.2 29.1 3.64E-07 7.50 0.00 815 19.1 668.3 29.1 3.10E-07 7.51 0.00 836 13.7 682.0 29.1 3.08E-07 7.49 0.00 863 15.1 697.1 29.1 2.64E-07 7.50 0.00 905 10.9 708.0 29.1 1.22E-07 7.50 0.00 930 4.2 712.2 29.1 7.92E-08 0.00 955 1.8 714.0 29.1 3.39E-08 7.48 0.00 977 1.0 715.0 29.1 2.14E-08 0.00 1004 1.9 716.9 29.1 3.32E-08 0.00 1030 0.4 717.3 29.1 7.25E-09 0.00 1075 0.7 718.0 29.1 7.33E-09 7.47 0.00 1100 0.4 718.4 29.1 7.54E-09 0.00 1128 0.4 718.8 29.1 6.73E-09 0.00 1148 0.4 719.2 29.1 9.43E-09 0.00 1173 0.2 719.4 29.1 3.77E-09 0.00 1198 1.0 720.4 29.1 1.89E-08 0.00 1223 0.3 720.7 29.1 5.66E-09 7.46 0.00 1242 0.2 720.9 29.1 4.96E-09 0.00 1268 0.3 721.2 29.1 5.44E-09 0.00 1293 0.1 721.3 29.1 1.89E-09 0.00 1322 0.7 722.0 29.1 1.14E-08 0.00 1363 0.3 722.3 29.1 3.45E-09 7.52 0.00 1383 0.3 722.6 29.1 7.07E-09 0.00 Hydraulic conductivity, pH and [MEK] data for Run E27 Elapsed Flow (mL) Cumulative Head k (cm/s) PH [MEK] Time (h) Flow (mL) (mg/L) 15 39.8 39.8 27.7 1.31E-06 7.62 5.90 42 83.2 123.0 27.7 1.53E-06 7.55 3.91 68 56.5 179.5 27.7 1.08E-06 7.57 2.19 91 38.4 217.9 27.7 8.26E-07 7.45 2.01 116 44.8 262.7 27.7 8.87E-07 7.51 2.13 Hydraulic conductivity, pH and [MEK] data for Run E28 Elapsed Time (h) Flow (mL) Cumulative Flow (mL) Head k (cm/s) pH [MEK] (mg/L) 22 21.4 21.4 37.4 3.57E-07 7.65 0.00 48 42.5 63.9 38.8 5.78E-07 7.61 1.04 68 39.1 103.0 38.8 6.91E-07 7.56 0.00 95 59.3 162.3 38.8 7.77E-07 7.51 0.56 117 52.5 214.8 38.8 8.44E-07 7.43 0.79 145 64:3 279.1 37.4 8.42E-07 7.50 0.86 167 51.3 330.4 37.4 8.55E-07 7.55 0.61 191 54.4 384.8 37.4 8.31E-07 7.54 0.85 215 52.1 436.9 38.8 7.68E-07 7.54 0.00 240 57.4 494.3 37.4 8.42E-07 7.52 0.50 261 44.5 538.8 38.8 7.49E-07 7.52 0.75 288 59.8 598.6 38.8 7.83E-07 7.54 0.78 312 55.5 654.1 38.8 8.18E-07 7.49 0.55 335 50.7 704.8 38.8 7.79E-07 7.57 0.74 361 59.4 764.2 38.8 8.08E-07 7.56 0.75 384 50.9 815.1 38.8 7.82E-07 7.58 0.92 403 45.4 860.5 38.8 8.45E-07 7.60 1.22 455 124.5 985.0 38.8 8.47E-07 7.57 1.24 475 49.6 1034.6 38.8 8.77E-07 7.57 1.10 503 60.5 1095.1 37.4 7.92E-07 7.56 0.00 527 43.9 1139.0 37.4 6.71E-07 7.58 0.00 552 35.6 1174.6 37.4 5.22E-07 7.59 0.00 599 36.8 1211.4 37.4 2.87E-07 7.59 0.00 624 13.0 1224.4 37.4 1.91E-07 7.60 0.00 650 12.2 1236.6 37.4 1.72E-07 7.58 0.00 672 9.7 1246.3 37.4 1.62E-07 7.55 0.00 694 10.4 1256.7 37.4 1.73E-07 7.52 0.00 720 10.8 1267.5 36.0 1.58E-07 7.50 0.00 743 9.9 1277.4 36.0 1.64E-07 7.47 0.00 792 22.4 1299.8 36.0 1.74E-07 7.45 0.00 814 9.8 1309.6 36.0 1.70E-07 7.43 0.00 841 10.8 1320.4 36.0 1.52E-07 7.50 0.00 864 9.6 1330.0 36.0 1.59E-07 7.49 0.00 884 8.2 1338.2 36.0 1.56E-07 7.47 0.00 932 22.5 1360.7 36.0 1.78E-07 7.48 0.00 962 33.9 1394.6 36.0 4.30E-07 7.47 0.00 982 69.5 1464.1 34.6 1.38E-06 7.49 2.18 1006 69.0 1533.1 36.0 1.09E-06 7.49 1.96 1032 61.7 1594.8 36.0 9.04E-07 7.45 0.00 1078 •46.9 1641.7 36.0 3.88E-07 7.46 0.00 1105 12.8 1654.5 38.8 1.68E-07 7.47 0.00 1127 9.4 1663.9 38.8 1.51E-07 7.50 0.00 1149 7.8 1671.7 38.8 1.25E-07 7.51 0.00 1175 7.9 1679.6 38.8 1.07E-07 7.52 0.00 1200 8.0 1687.6 38.8 1.13E-07 7.53 0.00 1224 5.5 1693.1 38.8 8.10E-08 7.49 0.00 1249 6.0 1699.1 38.8 8.49E-08 7.48 0.00 1271 7.3 1706.4 38.8 1.17E-07 7.47 0.00 1297 18.4 1724.8 38.8 2.50E-07 0.00 1321 12.7 1737.5 38.8 1.87E-07 7.48 0.00 1351 30.2 1767.7 38.8 3.56E-07 7.51 0.00 1376 20.2 1787.9 38.8 2.86E-07 7.52 0.00 1392 11.7 1799.6 38.8 2.59E-07 7.53 0.00 1418 25.0 1824.6 38.8 3.40E-07 7.53 0.00 1465 49.2 1873.8 38.8 3.70E-07 7.49 0.00 Hydraulic conductivity, pH and [MEK] data for Run E29 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [MEK] Time (h) Flow (mL) (mg/L) 22 0.0 0.0 37.4 48 45.9 45.9 38.8 6.24E-07 7.92 0.93 68 39.1 85.0 38.8 6.91E-07 7.75 4.21 95 59.9 144.9 38.8 7.84E-07 7.73 3.90 117 55.0 199.9 38.8 8.84E-07 7.77 2.96 145 72.3 272.2 37.4 9.47E-07 7.51 3.33 167 60.3 332.5 37.4 1.01E-06 7.52 3.52 191 67.4 399.9 37.4 1.03E-06 7.53 2.26 215 67.4 467.3 38.8 9.93E-07 7.54 2.07 240 76.3 543.6 37.4 1.12E-06 7.54 1.91 261 61.5 605.1 38.8 1.04E-06 7.51 3.16 288 84.2 689.3 38.8 1.10E-06 7.55 2.75 312 81.1 770.4 38.8 1.19E-06 7.56 1.74 335 75.0 845.4 38.8 1.15E-06 7.54 2.06 361 86.9 932.3 38.8 1.18E-06 7.53 2.01 384 72.4 1004.7 38.8 1.11E-06 7.50 1.87 403 65.8 1070.5 38.8 1.22E-06 7.58 2.40 455 204.2 1274.7 38.8 1.39E-06 7.57 2.09 475 100.2 1374.9 38.8 1.77E-06 7.59 2.30 503 147.9 1522.8 37.4 1.94E-06 7.58 4.19 Hydraulic conductivity, pH and [MEK] data for Run E30 Elapsed Flow (mL) Cumulative Head k (cm/s) pH [MEK] Time (h) Flow (mL) (mg/L) 20 3.1 3.1 38.8 5.48E-08 0.00 48 15.4 18.5 37.4 2.02E-07 8.11 0.00 72 18.2 36.7 37.4 2.78E-07 7.97 0.00 97 22.7 59.4 37.4 3.33E-07 7.91 0.00 144 52.4 111.8 37.4 4.09E-07 7.59 1.32 169 35.0 146.8 37.4 5.13E-07 7.50 1.22 195 38.3 185.1 37.4 5.40E-07 7.53 0.00 217 33.8 218.9 37.4 5.63E-07 7.52 0.00 239 37.6 256*.5 37.4 6.27E-07 7.52 0.00 265 41.2 297.7 36.0 6.03E-07 7.55 0.00 288 38.4 336.1 36.0 6.36E-07 7.56 0.00 337 80.9 417.0 36.0 6.29E-07 7.57 0.00 359 35.1 452.1 36.0 6.08E-07 7.58 0.00 386 42.4 494.5 36.0 5.98E-07 7.58 0.00 409 36.7 531.2 36.0 6.08E-07 7.56 0.00 429 31.5 562.7 36.0 6.00E-07 7.55 0.00 477 73.3 636.0 36.0 5.81E-07 7.54 0.00 507 48.9 684.9 36.0 6.21E-07 7.53 0.00 527 36.6 721.5 34.6 7.25E-07 7.52 0.00 551 41.7 763.2 36.0 6.62E-07 7.49 0.00 577 46.2 809.4 36.0 6.77E-07 7.48 0.00 623 78.8 888.2 36.0 6.52E-07 7.47 0.00 650 51.2 939.4 38.8 6.70E-07 7.50 0.00 672 42.0 981.4 38.8 6.75E-07 7.46 0.00 694 42.7 1024.1 38.8 6.86E-07 0.00 720 52.9 1077.0 38.8 7.19E-07 7.48 0.00 745 47.5 1124.5 38.8 6.72E-07 7.49 0.00 769 60.7 1185.2 38.8 8.94E-07 7.50 0.00 794 62.7 1247.9 38.8 8.87E-07 7.51 0.00 816 65.4 1313.3 38.8 1.05E-06 7.47 0.00 842 83.7 1397.0 38.8 1.14E-06 7.48 0.00 866 84.2 1481.2 38.8 1.24E-06 7.48 0.00 896 113.9 1595.1 38.8 1.34E-06 7.48 0.00 921 98.9 1694.0 38.8 1.40E-06 7.49 0.00 937 67.1 1761.1 38.8 1.48E-06 7.52 0.00 963 111.5 1872.6 38.8 1.52E-06 7.53 0.00 1010 209.3 2081.9 38.8 1.57E-06 7.54 0.00 

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