UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Coal treatment of wastewaters Hendren, Murray K. 1974

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-UBC_1974_A7 H45.pdf [ 3.1MB ]
Metadata
JSON: 831-1.0050516.json
JSON-LD: 831-1.0050516-ld.json
RDF/XML (Pretty): 831-1.0050516-rdf.xml
RDF/JSON: 831-1.0050516-rdf.json
Turtle: 831-1.0050516-turtle.txt
N-Triples: 831-1.0050516-rdf-ntriples.txt
Original Record: 831-1.0050516-source.json
Full Text
831-1.0050516-fulltext.txt
Citation
831-1.0050516.ris

Full Text

COAL TREATMENT OF WASTEWATERS by Murray K. Hendren B.A.Sc, University of B r i t i s h Columbia, 1969 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF APPLIED SCIENCE i n the Department of C i v i l Engineering We accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA A p r i l , 1974 In presenting t h i s thesis i n p a r t i a l f u l f i l m e n t of the requirements f o r an advanced degree at the University of B r i t i s h Columbia, I agree that the Library s h a l l make i t f r e e l y available f o r reference and study. I further agree that permission fo r extensive copying of t h i s thesis fo r scholarly purposes may be granted by the Head of my Department or by h i s representatives. It i s understood that copying or p u b l i c a t i o n of t h i s thesis f o r f i n a n c i a l gain s h a l l not be allowed without my written permission. Department The University of B r i t i s h Columbia Vancouver 8, Canada Date flprd 2.5, \314-A B S T R A C T The capacity of two B r i t i s h Columbia coals to remove heavy metals, organics and phosphates was evaluated using batch and column t e s t s . One coal was a l i g n i t e from the Hat Creek area, the other a medium v o l a t i l e bituminous from the Crowsnest area. Hat Creek coal was superior to Crowsnest coal for removal of a l l metals tested. Removals of heavy metals to trace values ( l e s s than 0.05 mg/l) were possible with both coals. Hat Creek coal removed almost completely a mixture of copper, zi n c , lead, n i c k e l and cadmium from s o l u t i o n . The capacity of Hat Creek coal f o r copper ions was i n the range of 0.5 to 1.0% by weight of the coal and for lead ions was 2 to 3% by weight of the c o a l . A sample c a l c u l a t i o n showed that 20 l b s . of crushed coal would be required to treat 1,000 gallons of waste containing 10 mg/l copper. Average e f f l u e n t concentration using that dosage would be 0.2 mg/l. I t was shown that the tested variables had the following e f f e c t s on the column capacity for removal of heavy metals: (1) Increasing grain s i z e of coal decreased capacity; (2) Increasing flow rate of wastewater decreased capacity; (3) Decreasing pH of wastewater decreased capacity; (4) Decreasing wastewater temperature had no e f f e c t on column capacity. i i i Tests performed on organics and soluble phosphates showed the coals to be unable to produce a high q u a l i t y e f f l u e n t from ei t h e r a beef extract or a sodium phosphate s o l u t i o n , thereby i n d i c a t i n g that the effectiveness of the coals i n t r e a t i n g municipal waste by an adsorption process would probably be very l i m i t e d . It i s recommended that further research be performed on removal of heavy metals by coal. A suggested course of action i s as follows: ( i ) Lab-scale t e s t i n g of several B r i t i s h Columbia coals to f i n d which ones are most e f f e c t i v e i n heavy metal removal, ( i i ) Comprehensive lab-scale t e s t i n g of the best coals i n ( i ) . ( i i i ) Determination of the technical and economic f e a s i b i l i t y of procurement and disposal of coal, (iv) P i l o t scale t e s t i n g of the most e f f e c t i v e coals on actual wastewaters, i f data from ( i i ) and ( i i i ) i ndicates coal treatment to be an economic process. TABLE OF CONTENTS Page ABSTRACT i i LIST OF TABLES ' v i LIST OF FIGURES v i i ACKNOWLEDGEMENT v i i i CHAPTERS I INTRODUCTION 1 II PROCEDURE 4 2 i l Introduction 4 2.2 Wastewaters Used 4 2.3 Testing Procedure 4 2.4 Coal Preparation 7 2.5 Batch Tests 8 2.6 Column Tests 9 II I PRESENTATION OF DATA 15 3.1 Composition of the Coals 15 3.2 Batch Test Data 16 3.2.1 General 16 3.2.2 Heavy Metal Removal 16 3.2.3 Beef Extract Removal 22 3.2.4 Phosphate Removal 22 3.2.5 Summary of Batch Test Observations 24 i v 3.3 Column Test Data 26 3.3.1 General 26 3.3.2 Copper Removal - Hat 2g Creek Coal 3.3.3 Copper Removal -Crowsnest Coal 39 3.3.A Removal of Lead - Hat Creek Coal 42 3.3.5 Removal of Heavy Metal Mixture 43 3.3.6 Regeneration 45 3.3.7 Beef Extract Removal 47 3.3.8 Phosphate Removal 47 3.3.9 Summary of Column Tests 49 IV POSSIBLE USES 51 4.1 I n d u s t r i a l Heavy Metal Removal 51 4.2 Treatment of Municipal Sewage 52 V CONCLUSIONS AND RECOMMENDATIONS 54 5.1 Conclusions 54 5.2 Recommendations 56 GLOSSARY OF TERMS 58 BIBLIOGRAPHY 59 APPENDIX I Tyler Mesh Series 60 II Sample Determination of Coal Capacity from a Breakthrough Curve 62 III Batch Test Data 64 LIST OF TABLES TABLE PAGE I Solutions Tested 5 II Composition of Coals 16 II I Summary of Tests and Capacities IV Capacity of 28/48 Hat Creek Coal 31 vi-LIST OF FIGURES Figure Page 1. Adsorption Isotherms f o r Copper 18 2. Adsorption Isotherms for Lead 20 3. Adsorption Isotherms f o r Zinc 21 4. Adsorption Isotherms for Beef Extract 23 5. Adsorption Isotherms f o r PO^ 25 6. Breakthrough Curve using Hat Creek 30 Coal and 100 mg/l Copper Solution 7. Breakthrough Curves for Three Grain 32 Sizes of Hat Creek Coal 8. Breakthrough Curves showing E f f e c t s 34 of Adsorbate pH and Adsorbate Flow Rate 9. Breakthrough Curves for Hat Creek and 36 Crowsnest Coals Treating a 10 mg/l Solution of Copper 10. Breakthrough Curves for Hat Creek and 38 Crowsnest Coals Treating a 0.7 mg/l Solution of Copper 11. Breakthrough Curves f o r Hat Creek and 40 Crowsnest Coals, Influent Concentration 100 mg/l Copper 12. Breakthrough Curves for Crowsnest Coal, 41 Showing E f f e c t s of Flow Rate 13. Breakthrough Curve f o r Hat Creek Coal, 44 Showing Capacity f or Lead 14. Breakthrough Curves for Hat Creek and 46 Crowsnest Coals Treating a 10 mg/l Solution of Copper. 15. Breakthrough Curves f o r Beef Extract 48 Solution using Hat Creek and Crowsnest Coals. v i i A C K N O W L E D G E M E N T The help of Mr. Cy Jones of I n t e r p r o v i n c l a l Patents Ltd. for the supply of the coals tested i s g r a t e f u l l y acknowledged. Also the help and encouragement of Dr. W.K. Oldham, Dr. R.D. Cameron, Mrs. E. MacDonald, Mr. R.D. Wetter, Mr. J.W. Atwater and Mrs. A.M. MacGillivray. v i i i This thesis i s dedicated to my wife Marg, without whose encouragement and support, the study would not have been possible. i x C H A P T E R I INTRODUCTION Anthracite coal has been i n use for several decades as a f i l t e r -ing medium for water supplies. Only recently, however, has the use of coal as an adsorbent for p u r i f y i n g wastewaters been examined. P r i o r to the study described i n t h i s t h e s i s , no B r i t i s h Columbia coals have been tested comprehensively f o r t h e i r a b i l i t y to remove impurities from wastewaters, even though the use of coal f o r tr e a t i n g wastewaters i n B r i t i s h Columbia seems p a r t i c u l a r l y worthy of research. Increasing population, i n d u s t r i a l growth, and p u b l i c pressure are f o r c i n g the Province to enact higher p o l l u t i o n control standards thereby increasing the need for inexpensive but e f f e c t i v e treatment methods. There i s a p o s s i b i l i t y that coal could be used for tr e a t i n g wastewaters e i t h e r p r i o r to or instead of being used as a f u e l . The research program reported i n t h i s thesis was undertaken to examine t h i s p o s s i b i l i t y . Coal, which i s a v a i l a b l e i n the Province i n large, e a s i l y mined deposits, has been reported [1,2,3,4] to have the c a p a b i l i t y of removing several types of impurities from wastewaters, including: (1) C o l l o i d a l organic material (2) Dissolved inorganic material (3) Solids normally separable i n conventional f i l t e r i n g processes. 1 2 The p o s s i b i l i t y e x i s t s that coal can remove a l l the above-named materials using a si n g l e contacting unit, thereby r e q u i r i n g a minimum land or f l o o r area f o r t r e a t i n g a complex waste. Coal, which i s r e l a -t i v e l y cheap compared with other adsorbent materials, may s e l l f o r as l i t t l e as $15 per ton. Activated carbon, on the other hand costs approximately $500 for the same amount. Further savings might be effected i f the coal could be used for f u e l a f t e r use i n a wastewater treatment process. Investigators have found that most coals exhibit a c a p a b i l i t y to remove impurities from waste streams but that the magnitude of the removal capacity varies from coal to coal. Johnson and Kunka [1] reported that c e r t a i n coals had the capacity to remove up to 4% of t h e i r weight i n oxygen demanding materials, measured i n terms of C.O.D., from s e t t l e d raw sewage. The coals used by Johnson and Kunka were ground to approximately 50/70 mesh* and contacted with the sewage i n a batch system. Shannon [2],using s i m i l a r grain s i z e d coal and a synthetic sewage, found that the best coal tested had a capacity of removing only 0.1% of i t s weight i n oxygen demanding materials, measured i n terms of C.O.D. Both Johnson's and Shannon's studies were performed on a laboratory scale. * T y l e r Mesh Series (See Appendix I ) . 3 The Rand Corporation [3] operated a 10,000 U.S. gal/day p i l o t plant that used 18/120 mesh coal as a consumable precoat f i l t e r to treat raw sewage and secondary e f f l u e n t . The r e s u l t s showed that a 90% decrease i n suspended s o l i d s and a 40 to 60% decrease i n phosphates and C.O.D. could be expected i f a coal f i l t e r was used to treat e i t h e r raw sewage or secondary e f f l u e n t . The L i n f i e l d Research I n s t i t u t e i n McMinnville, Oregon [4] has completed a preliminary study on the removal of inorganic ions from solutions with coal. A l l cations tested (copper, zinc, barium, i r o n , manganese) were removed to some extent by the co a l . Toxic anions such as chromate and cyanide were also removed. A research program was therefore undertaken to examine the f e a s i -b i l i t y of u t i l i z i n g B r i t i s h Columbia coals to tre a t wastewaters. The reasons for undertaking the program are summarized as follows: (1) Coal has been shown to remove a wide v a r i e t y of materials from wastewaters. (2) The increased population and i n d u s t r i a l growth of B r i t i s h Columbia dictates high p o l l u t i o n control standards and therefore e f f e c t i v e treatment methods. (3) There are large reserves of coal i n B r i t i s h Columbia that could possibly be used for treatment purposes. (4) No B r i t i s h Columbia coals have been tested comprehensively fo r t h e i r a b i l i t y to renovate wastewaters. C H A P T E R II PROCEDURE 2.1 Introduction Two coals were crushed, washed, sieved to various grain s i z e s and then tested f o r t h e i r c a p a b i l i t y to remove pollutants from synthetic wastewaters. Batch te s t s were performed to provide general data with which to design column experiments. Column tests were subsequently performed to e s t a b l i s h the capacity of the coals to removal several impurities from s o l u t i o n under varying conditions of flow rate, wastewater pH, wastewater temperature and grain s i z e of coal. Solutions containing copper sulphate, lead n i t r a t e , zinc sulphate, n i c k e l n i t r a t e , cadmium n i t r a t e , sodium phosphate and beef extract were used to simulate actual wastewaters. 2.2 Wastewaters Used Table I indicates the simulated wastewaters, the materials used i n the synthetic wastewater, and the major sources of the wastewaters amenable to p o t e n t i a l coal treatment. 2.3 Testing Procedure Testing was performed i n accordance with Standard Methods for 4 TABLE I SOLUTIONS TESTED ACTUAL WASTEWATER SYNTHETIC WASTEWATER SOURCE OF ACTUAL WASTEWATER Copper i o n s CuSO^ Lead i o n s Pb ( N 0 3 ) 2 M e t a l f i n i s h i n g I n d u s t r i e s Z i n c i o n s ZnSO^ L a n d f i l l l e a c h a t e N i c k e l i o n s N i ( N 0 3 ) 2 M i n i n g e f f l u e n t s Cadmium i o n s Cd ( N 0 3 ) 2 Oxygen demanding m a t e r i a l s Beef E x t r a c t * M u n i c i p a l sewage, I n d u s t r i a l waste P h o s p h a t e s S od ium P h o s p h a t e M u n i c i p a l sewage * r a t i o o f COD: TKN: 9:1 6 Examination of Water and Wastewater, 13th E d i t i o n . Heavy metal concentrations were measured using an atomic absorption spectro-photometer.* The Kje l d a h l test rather than the C.O.D. or B.O.D. tests was used to in d i c a t e the amount of oxygen demanding materials present i n a sample. Other researchers [2] found that the fin e s added by the coal made the determination of oxygen demanding materials by the C.O.D. test imprecise. The B.O.D. test was also inconvenient, from a time standpoint. Precise r e s u l t s were obtained using t o t a l K jeldahl nitrogen (TKN) as an i n d i c a t i o n of oxygen demanding materials, although the use of TKN as such an i n d i c a t o r has some drawbacks. Kjeldahl nitrogen tests give a good i n d i c a t i o n of proteinaceous material but do not give any i n d i c a t i o n of carbohydrates. Therefore, i f K j e l d a h l nitrogen were used as an i n d i c a t o r f or a coal treatment process, the coal need only remove a large portion of the p r o t e i n -aceous matter to f a l s e l y appear to be achieving e f f i c i e n t treatment. Because coal does p r e f e r e n t i a l l y adsorb proteinaceous materials over carbohydrates such as sugars [2], the strong p o s s i b i l i t y e x i s t s that the degree of treatment measured i n t h i s study by using K j e l d a h l tests i s f a l s e l y o p t i m i s t i c . Treatment e f f i c i e n c i e s calculated by using data from K j e l d a h l tests therefore w i l l probably be higher than those which would be * J a r r e l l - A s h MV-500 7 calculated using C.O.D. t e s t s . The conclusions of the report, however, are s t i l l considered to be v a l i d , but only because the data showed that the coal columns were unable to e f f e c t i v e l y remove organic material from s o l u t i o n . As explained above, the actual treatment of the organic materials i s probably worse than that measured. I t can therefore be s a i d that the poor r e s u l t s noticed i n t h i s study are the best that can be expected. Had the r e s u l t s of the study been more o p t i m i s t i c the question of using nitrogen as an i n d i c a t o r of organic materials would have required further consideration. v 2.4 Coal Preparation A l l coal used throughout the t e s t i n g program was of a s p e c i f i c grain s i z e and was thoroughly washed. The coal was ground using a s e r i e s of jaw and cone crushers, then wet sieved to the following three grain s i z e s : (Tyler mesh series) * 14/28 28/48 48/65 Af t e r being sieved, the i n d i v i d u a l grain sizes were back-washed i n a p l e x i g l a s s column u n t i l a l l fines were removed. The coal was then dried at 103°C and stored at room temperature u n t i l used. * See Appendix I. 8 2.5 Batch Tests Batch tests were performed to obtain data with which to design continuous flow column experiments. The experimental procedure for batch t e s t i n g was as follows: (i) A measured amount of wastewater of known concentration was added to each of several f l a s k s , ( i i ) Varying but known amounts of coal were added to each f l a s k . ( i i i ) The coal-wastewater mixture was shaken for 24 hours to assure that equilibrium conditions were established, (iv) The equilibrium concentration of wastewater i n each f l a s k was measured, (v) The removal capacity of the coal i n each f l a s k was calculated. Plots were made of the capacity of the coal to remove an impurity versus the equilibrium concentration of the impurity i n contact with the coal. Such plo t s are c a l l e d adsorption isotherms, as the data for each graph i s gathered at a constant s o l u t i o n temperature, and because the mechanism of adsorption i s probably involved i n the removal of pollutants by c o a l . The term adsorption i s meant to include ph y s i c a l adsorption, chemisorption and ion exchange. A l l batch tests except those using beef extract were performed at room temperature. The beef extract removal tests were performed at 4°C to prevent b i o l o g i c a l degradation of the s o l u t i o n during the 9 24 hour contact time. The value of batch test data i s l i m i t e d by the f a c t that data i s gathered at equilibrium conditions. Most treatment units employing ion exchange or adsorbent materials, however, operate on a continuous flow b a s i s . The adsorbent or ion exchange materials are placed i n a column through which wastewaters are passed u n t i l the removal capacity of the materials i s exhausted. Depending on factors such as flow rate, column depth and column cross s e c t i o n a l area, equilibrium conditions may or may not e x i s t i n such flow-through operations. In l i g h t of th i s f a c t , batch test data should not be used as a v a l i d i n d i c a t i o n of how w e l l a material tested would perform i n a f u l l scale column operation. The most important use f o r batch test data i s the design of lab-scale column experiments. Data from batch tests can save time and e f f o r t when designing and running a lab-scale column. Data from the column tests can then i n turn be used to design a p i l o t scale f a c i l i t y i f the lab scale tests are successful. 2.6 Column Tests Results from column tests can be used to design a p i l o t - s c a l e column experiment i f coal treatment seems economically f e a s i b l e . Laboratory scale column tests were therefore performed to demon-st r a t e the a b i l i t y of the coal to remove impurities from waste-water on a flow-through basis and to gain i n s i g h t into the f e a s i -b i l i t y of e s t a b l i s h i n g p i l o t scale t e s t s . 10 Column tests were performed i n the following manner: (i ) A predetermined amount of coal was placed i n a column, ( i i ) Wastewater was passed through the coal at a c o n t r o l l e d flow rate. ( i i i ) The e f f l u e n t concentration was measured at regular i n t e r v a l s based on through-put volume, (iv) A p l o t was made of e f f l u e n t concentration versus through-put volume. In the early stages of any column operation the e f f l u e n t concen-t r a t i o n of impurity w i l l be l e s s than the i n f l u e n t concentration by an amount dependent on several f a c t o r s , i n c l u d i n g type and grain s i z e of coal i n the column, flow rate, pH, temperature, concentrations, and composition of the wastewater. As the time of operation increases, the capacity of the adsorbent i s gradually exhausted and the e f f l u e n t concentration approaches that of the i n f l u e n t . A p l o t of e f f l u e n t concentration versus throughput volume i s generally S-shaped, s i m i l a r to the curve shown i n Figure 6. There are two parameters which must be measured to determine the effectiveness of an adsorbent material to p u r i f y wastewaters under any given condition of flow rate, pH, temperature and impurity concentration. These are: (i ) The i n f l u e n t and e f f l u e n t concentrations from which a % treatment can be calculated, ( i i ) The length of time an amount of coal can produce an e f f l u e n t of a given q u a l i t y i . e . the weight capacity of the coal to remove an impurity. 11 As previously mentioned, the capacity of the adsorbent i s exhausted and the e f f l u e n t concentration approaches that of the i n f l u e n t as time of column operation progresses. Presumably when the i n f l u e n t and e f f l u e n t concentrations are equal the adsor-bent w i l l be completely spent. When the e f f l u e n t concentration i s l e s s than the i n f l u e n t , however, only a c e r t a i n f r a c t i o n of the coals capacity w i l l have been u t i l i z e d . This f r a c t i o n would depend upon the value of e f f l u e n t concentration at which the capacity i s cal c u l a t e d . The e f f l u e n t concentration at which we are most interest e d i n c a l c u l a t i n g the capacity of the coal i s that above which we can no longer use the column. Such a concentration i s c a l l e d the breakthrough concentration and depends on factors such as: (i) P o l l u t i o n control regulations ( i i ) Water re-use c r i t e r i a ( i i i ) whether or not another column i s placed downstream of the column i n question. Because of the d i f f e r e n t factors involved, i t i s d i f f i c u l t to p r e d i c t or assume a breakthrough concentration that would be applicable to an actual i n s t a l l a t i o n . Therefore, i n most instances i n t h i s study, the corresponding coal capacities were given f o r three breakthrough concentrations for each column t e s t . Another parameter sometimes reported i n t h i s study i s the average e f f l u e n t concentration p r i o r to breakthrough, simply the t o t a l weight of impurity passed through the column divided by the t o t a l throughput. I t indicates the e f f l u e n t q u a l i t y attainable on 12 an average b a s i s . Sample calc u l a t i o n s are shown i n Appendix I I . Obtaining an accurate breakthrough curve requires frequent sampling of the column e f f l u e n t . The column must therefore be attended on a continuous b a s i s . Coal volumes used were therefore l i m i t e d to that amount which would allow exhaustion of the column's removal capacity a f t e r a reasonable time. (The volume of coal would not be so c r i t i c a l i f automatic feed and sampling devices were a v a i l a b l e ) . The amount of coal to be used was decided i n the following manner: (i) A maximum time of operation was chosen as being 16 hours, ( i i ) Flow rates through the columns were chosen i n l i n e with commercial treatment processes. (This i s discussed further i n t h i s s e c t i o n ) . ( i i i ) Column sizes were chosen according to equipment a v a i l a b l e , (iv) Flow through the column during the 16 hr. period was calculated. (v) Weight of impurity passing through the column i n the 16 hour period was calculated, (vi) The capacity of the coal for removing the impurity at the p a r t i c u l a r i n f l u e n t concentration tested was estimated from batch t e s t data, ( v i i ) The weight of coal required i n the column was calculated from (v) and ( v i ) . Using r e a d i l y a v a i l a b l e 100 ml burettes as columns, i t was found that approximately 30 grams of coal i n each column would permit most 13 runs to be terminated within 12 to 16 hours. T h i r t y grams of coal f i l l e d the columns to a depth of approximately 1 foot. The flow 2 rate through the columns was approximately 1 gallon / f t /min. which, 3 i n the case of t h i s study, was also 1 g a l / f t /min., as the column 2 depth was one foot. Occasionally a flow rate of 5 g a l l o n s / f t /min. was used to show the e f f e c t s of using such a rate or to decrease the time to breakthrough to p r a c t i c a l l i m i t s . For comparison, flow rates f or commercial contact or f i l t e r processes are as follows: 2 Rapid Sand F i l t r a t i o n 1-5 g a l / f t /min. 2 Ion Exchange 1-10 g a l / f t /min. 2 Activated Carbon Adsorption 1-10 g a l / f t /min. Residence times of adsorbate i n the columns, based on empty 2 columns, were 7.5 minutes for the flow rate of 1 g a l / f t /min. and 2 1.5 minutes f o r a flow rate of 5 g a l / f t /min. Based on actual void space i n the column the residence times would be about 3.7 minutes and 0.75 minutes re s p e c t i v e l y . The grain sizes used i n the column tests were 14/28, 28/48 and 48/65. The majority of testing was done with 28/48. The i n f l u e n t concentration of the impurity, the i n f l u e n t pH, and the i n f l u e n t temperature were adjusted during the column t e s t i n g so that the e f f e c t s of these variables on column operations could be determined. Complete d e t a i l s of the column tests as performed, including type of coal used, impurity removed, i n f l u e n t concentration 14 of Impurity, i n f l u e n t pH, i n f l u e n t temperature, grain s i z e of coal and flow rate of wastewater are outlined i n the following chapter. C H A P T E R I I I PRESENTATION OF DATA-3.1 Composition of the Coals Due to lack of proper f a c i l i t i e s to determine the exact compositions of coals, i t was necessary to approximate the composi-tions with values from l i t e r a t u r e . The o r i g i n s of the coals were known, and therefore the compositions could be estimated from samplings of the general c o a l f i e l d as reported by the Canada Department of Mines. [5] (See Table II) Thus, the compositions reported are not exactly the same as the compositions of the coals used i n the experiments. They are, however, s a t i s f a c t o r y for_the purposes of t h i s study. The ash contents of the coals were checked by heating the coal to 550°C f o r s i x hours. Values of ash content for the Crowsnest coal agreed almost exactly with published f i g u r e s . However, the ash content of the Hat Creek coal used for experimenting was twice that reported i n the l i t e r a t u r e , thereby i n d i c a t i n g that coal samples vary i n composition depending on l o c a t i o n within the c o a l f i e l d . This fac t could be important when more comprehensive studies are c a r r i e d out i n attempts to f i n d the removal mechanism(s) involved i n coal treatment or to f i n d the most e f f i c i e n t coal f or coal treatment. Several samples of a given c o a l f i e l d may have to be tested to see 15 16 which gives the best r e s u l t s . TABLE II COMPOSITION OF COALS Parameter Hatcreek Crowsnest % moisture 8 1 % v o l a t i l e matter 36 22 % f i x e d carbon 47 65 % ash 9* 11 % sulphur 0.5+ 0.7+ * Actual Analysis of coal showed 20% ash + Data f o r coal a c t u a l l y used. 3.2 Batch Test Data 3.2.1 General Batch tests were performed using two grain sizes of each of the two coals. Substances used separately i n s o l u t i o n to approximate wastewaters were copper sulphate, lead n i t r a t e , z i n c sulphate, lead n i t r a t e , sodium phosphate and beef extract. Generally, during the batch t e s t s , the water was clouded due to p a r t i c l e break-up of the coal. Hat Creek coal was p a r t i c u l a r l y susceptible to p a r t i c l e break-up. Phosphate samples, requiring c o l o r i m e t r i c a n a l y s i s , were centrifuged before t e s t i n g . 3.2.2 Heavy Metal Removal The batch tests showed that the coals tested had the capacity 17 to remove heavy metals from s o l u t i o n . The capacity of the coal f o r metals depended on the type of coal used, the grain s i z e of the coal, the exact metal involved and the equilibrium concentration of the metal s o l u t i o n . S p e c i f i c batch test data i s shown i n Appendix I I I . The isotherms p l o t t e d from the batch tests i n v e s t i g a t i n g copper removal are shown i n Figure 1. The curves show the following: - The capacity of the coal increased with increasing e q u i l i -brium concentration of copper i n s o l u t i o n up to a l i m i t of about 100 mg/1. At concentrations above 100 mg/1 the coal capacity does not change s i g n i f i c a n t l y . An exception i s 48/65 Hat Creek coa l , the capacity of which increased up to 300 mg/1. - For a p a r t i c u l a r grain s i z e and equilibrium concentration, the Hat Creek coal had a higher capacity than the Crowsnest coal. - For a p a r t i c u l a r coal and equilibrium concentration, the smaller grain s i z e coal had the higher capacity. - The maximum capacity attained was 17 mg/gm of coal. This was measured f o r Hat Creek coal, grain s i z e 48/65, at an equilibrium concentration of 300 mg/1. Batch isotherms p l o t t e d from lead removal studies showed the same trends as those p l o t t e d from the copper studies. The capacity of coal increased with increasing equilibrium lead 20r D 18 O O <+- 16 o E 14 T J 12 > O 10 £ CD 8 CJ-E — - 6 6 4 o QL O 2 C J 0 Crowsnest 48/65 Hat Creek 28/48 Crowsnest 28/48 •O •-a o 100 200 300 400 Equ i l ib r ium concentrat ion mg/l i ter 500 FIG. I ADSORPTION ISOTHERMS FOR COPPER. 19 concentration and decreasing grain s i z e . Hat Creek coal was superior to Crowsnest co a l . Capacity as high as 45 mg of lead/gm of coal was observed. (Figure 2). Similar trends again were obtained when using zinc as the adsorbate. (Figure 3). Hat Creek coal was o r i g i n a l l y used i n addition to the Crowsnest coal i n the zinc batch t e s t s , but the r e s u l t s were discarded due to s c a t t e r . Figure 3 shows the following: - the capacity of the coal increases with increasing equilibrium concentration of zinc. - the highest capacity calculated was exhibited by the 48/65 grain s i z e and amounted to 14 mg Zn/gm of coal. This value was calculated at an equilibrium concentra-t i o n of 425 mg/l. The flasks containing the batch t e s t materials were v i s u a l l y examined c a r e f u l l y a f t e r each test to make sure p r e c i p i t a t i o n of the heavy metals was not occurring. In each case, no trace of a p r e c i p i t a t e could be found on the bottom of the f l a s k . There i s only a minute p o s s i b i l i t y that any p r e c i p i t a t e formed would s t i l l be i n suspension and not measured i n the tes t i n g procedure. Such a suspension would give very e r r a t i c readings on the atomic absorption unit and such an e r r a t i c phenomenon was not noticed i n t h i s study. I t therefore seems that the coal removes the metals from s o l u t i o n by an adsorption process. FIG. 2 ADSORPTION ISOTHERMS FOR LEAD 21 FIG.3 ADSORPTION ISOTHERMS FOR ZINC 22 3.2.3 Beef Extract Removal Batch tests were performed on a beef extract solution kept at 4°C. The low temperature was necessary to ensure that no biological degradation occurred during the 24 hour contact time. Figure 4 shows the results of the tests. The best results were obtained using Hat Creek coal, 48/65 grain size. Increasing the grain size decreased the capacity of the coal such that the capacity of the 48/65 Hat Creek coal was 1.8 times higher than the capacity of the 28/48 Hat Creek coal. The maximum capacity of 48/65 Hat Creek coal was found to be 5 mg. of Total Kjeldahl Nitrogen/gm of coal at an organic nitrogen concentration of 200 mg/l. In terms of C.O.D.* this value would correspond to approximately 45 mg C.O.D./gm of coal at an equilibrium C.O.D. concentration of 1,800 mg/l. Crowsnest 48/65 coal was also tested, but the removals were well below those found using Hat Creek coal. The maximum capacity calculated for Crowsnest coal was 15 mg C.O.D./gm of coal. 3.2.4 Phosphate Removal It was found that the capacity of Hat Creek and Crowsnest coals for a soluble phosphate solution was almost negligible. * ratio of C.O.D. to TKN for beef extract = 9:1. 23 FIG. 4 ADSORPTION ISOTHERMS FOR BEEF EXTRACT. 24 Figure 5 shows the isotherms plotted using 28/48 Hat Creek and Crowsnest coals. The Hat Creek coal removed 0.1 mg PO /^gm of coal (0.03 mg P/gm of coal), while the Crowsnest coal did not measurably remove any phosphate. 3.2.5 Summary of Batch Test Observations In general, i t was found that the coal tested had the ab i l i t y to remove both heavy metals and beef extract from solution. Soluble phosphate was not removed to any extent by either coal. The batch tests showed that the capacity of the coal to remove impurities increased with increasing impurity concen-tration in the wastewater, and that the capacity increased with decreasing grain size within the grain size range tested. Hat Creek coal was superior to Crowsnest coal in removal of heavy metals, beef extract and phosphates. Capacities as high as 45 mg of lead/gm of coal, 17 mg of copper/gm of coal, 15 mg of zinc/gm of coal, and 5 mg TKN/gm of coal were recorded using Hat Creek coal ground to a 48/65 grain size. No precipitates were noticed on the bottoms of the flasks and no suspended metal precipitates were encountered during testing with the atomic absorption unit. FIG. 5 ADSORPTION ISOTHERMS FOR P 0 4 . 26 Data gathered i n the batch tests was used as a guideline f o r designing the column t e s t s , the r e s u l t s of which are reported i n the next sec t i o n . 3.3 Column Test Data 3.3.1 General Column tests were performed to e s t a b l i s h how much of a dissolved impurity the coal removes on a continuous flow-through b a s i s . The e f f e c t s of the following variables were examined: (i) Grain s i z e of coal ( i i ) Flow rate ( i i i ) pH of adsorbate s o l u t i o n (iv) Concentration of adsorbate (v) Temperature of adsorbate s o l u t i o n (vi) Composition of adsorbate ( v i i ) Type of coal S p e c i f i c information concerning the t e s t i n g and r e s u l t s i s shown i n Table I I I . As calculated from batch test data, time to completion of each column test was never more than 16 hours. Breakthrough curves were p l o t t e d and analyzed to c a l c u l a t e the capacity of the coal i n the column. The capacity of the coal was calculated f o r each of several a r b i t a r i l y assumed breakthrough concentrations i n the following manner: T A B L E I I I SUMMARY OF T E S T S AND C A P A C I T I E S T e s t No . C o a l G r a i n S i z e impurity C o n c ' n o f Impurity R a t e F l o w G a l / F t 2 / M i n T e m p e r a t u r e C a p a c i t y a t f o l l o w i n g B r e a k t h r o u g h C o n c e n t r a t i o n s (mg o f I m p u r i t y / g m o f c o a l ) 10% 50% 75% 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 16 17 IIC HC HC HC HC HC HC HC CN CN CN CN HC HC HC HC CN 28/48 14/28 48/65 28/48 28/48 28/48 2 8/48 28/48 28/48 28/48 28/48 28/48 28/48 28/48 28/48 28/48 28/48 Copper Copper Copper Copper Copper Copper Copper Copper Copper Copper Copper Copper Lead Beef E x t r a c t Beef E x t r a c t NaH 2P0 4 N a H 2 P 0 4 100 mg/l 100 mg/l 100 mg/l 100 mg/l 100 mg/l (pH-2} 100 mg/l 10 mg/l 0.7 mg/l 100 mg/l 100 mg/l 10 mg/l 0.7 mg/l 300 mg/l 2 3.5 mg/l TKN 23.5 mg/l TKN 25 mg/l P 0 ~ 3 27 m g / l P O - 3 4 1 1 1 5 1 1 5 5 1 5 5 5 1 1 1 1 23°C 23°C 23°C 23°C 23°C 15°C 23°C 23°C 23°C 2 3°C 23°C 23°C 23°C 15°C 15°C 23°C 23°C 4 . 3 3 . 4 6 . 1 3 . 6 1 . 0 4 . 4 5 . 3 2 . 5 0 . 7 3 . 0 2 2 . 5 0 6 . 1 5 . 7 7 . 7 4.7-1 . 1 6 . 1 3 . 1 1 . 5 2 4 . 0 0 . 1 5 TKN 0 . 1 TKN 0 0 6 7 8 15 5 . 0 2 . 0 Indicates values unable to be calculated. ro 28 (i) The weight of impurity that entered the column p r i o r to breakthrough was calculated by mult i p l y i n g the throughput volume at breakthrough by the i n f l u e n t concentration of impurity, ( i i ) The weight of impurity that l e f t the column p r i o r to breakthrough was calculated by taking the area under the breakthrough curve and to the l e f t of the through-put volume at breakthrough, ( i i i ) The weight of impurity removed by the column was calculated by subtracting ( i i ) from ( i ) . (iv) The coal capacity was calculated by d i v i d i n g the weight of impurity removed by the weight of coal i n the column. In some cases, the average e f f l u e n t concentration u n t i l breakthrough was calculated. This c a l c u l a t i o n was performed by d i v i d i n g the weight of impurity leaving the column p r i o r to breakthrough ( ( i i ) above) by the throughput volume p r i o r to breakthrough. Average e f f l u e n t concentration i s that concentration that would be expected i f a l l the throughput from a given column test p r i o r to breakthrough were mixed together and measured. Sample ca l c u l a t i o n s of coal capacity and average e f f l u e n t concentration are shown i n Appendix I I . 3.3.2 Copper Removal - Hat Creek Coal Copper sulphate was the most frequently used adsorbate i n the column t e s t s , and was used to represent a waste containing 29 dissolved copper. The breakthrough curve shown i n Figure 6 represents a time-plot of Test 1 i n Table I I I . The shape of the curve i s t y p i c a l f o r i o n exchange or absorption columns, and i s representative of the breakthrough curves found f o r most of the tests outlined i n Table I I I . Table IV shows the values of coal capacity and average e f f l u e n t concentration for Hat Creek coal t r e a t i n g a 100 mg/1 so l u t i o n of copper. The table shows c l e a r l y that the design capacity of a column w i l l be dependent upon the allowable average and/or maximum e f f l u e n t concentration s t i p u l a t e d by regulations or water re-use considerations. For instance, i f the average e f f l u e n t concentration required i s 0.5 mg/1, then only 1.9 mg/gm of capacity or only 25% of the t o t a l coal capacity could be u t i l i z e d . In order to make use of the higher coal capacities and s t i l l have a high q u a l i t y e f f l u e n t , i t would be necessary to use columns i n s e r i e s , the l a s t column i n the serie s acting as a p o l i s h i n g column. I t was found that the capacity of the coal i n column operation increased with decreasing grain s i z e of coal , confirming e a r l i e r trends noticed i n the batch t e s t s . Breakthrough curves p l o t t e d using 14/28, 28/48 and 48/65 Hat Creek coal are shown i n Figure 7 to i l l u s t r a t e the O FIG. 6 BREAKTHROUGH CURVE USING HAT CREEK COAL AND lOOmg/liter COPPER SOLUTION. TABLE IV CAPACITY OF 28/48 HAT CREEK COAL A d s o r b a t e 100 mg/1 Cu. F l o w r a t e 1 g a l . / f t 2 / m i n . B r e a k t h r o u g h C o n c e n t r a t i o n (% of I n f l u e n t ) C a p a c i t y of C o a l (mg/gm) A v e r a g e E f f l u e n t C o n c e n t r a t i o n ( C a l c u l a t e d % of i n f l u e n t ) 1 1.88 0.5 5 3 . 7 1.6 10 4.3 2.4 25 5.3 5.8 50 6.1 11.5 75 7 . 0 25.8 100 ( e s t ) 8 . 2 49 Influent concentration lOOmg/liter Throughput volume in liters F I G 7 BREAKTHROUGH CURVES FOR THREE GRAIN SIZES OF HAT CREEK C O A L . 33 grain size effect. On the average the 28/48 grain size had 1.2 times the capacity of the 14/28; and the 48/65 grain size had 1.3 times the capacity of the 28/48. The increase in capacity obtained by using 48/65 over 14/28 was thus approximately 50%. More details are shown in Table III. Increasing the flow rate through the column had the effect of slightly decreasing the column capacity. Break-through curves for the two column tests described in test 1 and 4, Table III and shown in Figure 8, can be compared to show the effect. Increasing flow rate by a factor of five decreased the column capacity by only 20% (Table III). Therefore, a column can be of very small size and s t i l l maintain 80% of the unit capacity of a column 5 times as large. In industrial situations where floor space is at a premium, the f l e x i b i l i t y of size may make a coal treatment process particularly attractive. The pH of the incoming waste was shown to affect the capacity of coal in the columns considerably. L i t t l e removal of copper was obtained when the wastewater pH was a r t i f i c i a l l y depressed to 2. Data in Table III, calculated from the break-through curves in Figure 8, show that the column treating^the influent having low pH had only 15 to 25% of the capacity of the column treating the influent having the higher natural pH of the copper sulphate solution. pH adjustment may therefore ~ I 10! £ | 0 0 1 9 0 £ 80| U J •- 70 2. 6 0 CL ° I <-> 5 0 c o c CD O c o (_> 4 0 | 30 20 10 Influent concentration lOOmg/liter 9 - > 0 Flow rate I gal./ft./min pH = 2 Flow rate 5gal./ft.2/min pH = 5 Flow rate I gal./ft.2/min pH = 5 I ft. 32 gm Depth of coal Wt. of coal 0 ,0 2.0 3.0 Throughput volume (liters ) 4.0 FIG. 8 BREAKTHROUGH CURVES SHOWING EFFECTS OF ADSORBATE pH AND ADSORBATE FLOW RATE . 35 be necessary i n order to use coals f o r t r e a t i n g a c i d mine drainage, which i s usually of low pH. No reasons can be given at the present time f or the fa c t that low removals were observed at a pH of 2. More research i s required to more f u l l y determine pH e f f e c t s on heavy metal removal. I t was found that coal had the c a p a b i l i t y of removing high percentages of copper from d i l u t e s o l u t i o n s . Tests were performed using a 10 mg/1 and a 0.7 mg/1 i n f l u e n t s o l u t i o n of copper, 28/48 grain s i z e c o a l , and a flow rate of 5 g a l / 2 f t /min. The high flow rate was required i n order to terminate the run i n a reasonable time period. The break-through curve p l o t t e d using a 10 mg/1 copper s o l u t i o n as the wastewater (Figure 9) shows that using Hat Creek coal, the e f f l u e n t concentration was less than 1% of the i n f l u e n t a f t e r 10 l i t e r s of throughput. The capacity of the coal and average e f f l u e n t concentration (See d e f i n i t i o n on Page 58) for a 10% breakthrough concentration were 5.25 mg of copper/gm of coal and 0.2 mg/1 copper r e s p e c t i v e l y . I t there-fore appears that Hat Creek coal i s capable of t r e a t i n g d i l u t e solutions of copper e f f e c t i v e l y while s t i l l maintain-ing a capacity f o r copper ions i n the range of 0.5% by weight of c o a l . In actual f a c t , the removal capacity of the coal when tr e a t i n g a 10 mg/1 s o l u t i o n i s better than that found when t r e a t i n g the 100 mg/1 s o l u t i o n , i f a breakthrough concen-II 10 r Influent concentration 9.9mg/liter £ c o c a) o c o o c a> 3 LU 8 7 6 5 4 i 31 21 I 0 L 0 Crowsnest column depth wt.of coal grain size flow rate influent pH I ft. 32gm 28/48 5gal./ft 2/min. 5.8 7 8 9 10 II 12 13 14 15 16 17 18 T h r o u g h p u t v o l u m e in l i te rs 19 2 0 FIG. 9 BREAKTHROUGH CURVES FOR HAT CREEK AND CROWSNEST COALS TREATING A lOmg/liter SOLUTION OF COPPER . 37 t r a t i o n of 10% of i n f l u e n t i s used as a ba s i s . The capacity of the coal f o r tr e a t i n g the more concentrated waste was only 4.3 mg/gm at 10% breakthrough (Table I I I , Test 4). The increased capacity of the coal noticed when t r e a t i n g a d i l u t e s o l u t i o n was not expected because of trends noticed i n the batch tests and i n a l l p r o b a b i l i t y would not e x i s t i f the curve p l o t t e d f o r the 10 mg/1 s o l u t i o n could be completed to show 100% breakthrough and then compared to the 100 mg/1 100% breakthrough curve. In other words, the column geometry, flow rate, grain s i z e of coal, or some combination of these factors probably changed the shape of the 10 mg/1 curve to make treatment of a d i l u t e s o l u t i o n to a 10% breakthrough point appear p a r t i c u l a r l y appealing. The most important fa c t i s that there i s no s i g n i f i c a n t l o s s of removal capacity when tr e a t i n g a more d i l u t e waste with Hat Creek coal. To inve s t i g a t e t h i s point further, a test was performed using a 0.7 mg/1 copper s o l u t i o n as the i n f l u e n t . The r e s u l t s of the test using Hat Creek coal to treat the very d i l u t e copper wastewater are shown i n Figure 10. The figur e shows that e f f l u e n t concentrations lower than 0.05 mg/1 of copper ( l i m i t of detection) are obtainable with coal treatment. Because of time of running constraints no meaningful figures on coal capacity could be obtained from these t e s t s . S c o c o c o c C D 3 i.o -0 . 9 -0 . 8 -0 .7 0 .6 0 . 5 0 .4 -0 . 3 -£ 0 .2 h 0.1 0 . 0 5 column depth wt. of coal grain size flow rate Influent concentration 0.7mg/liter I ft. 32 gm 28/48 2 I gal./ft. / min. Crowsnest Hat Creek-—9 7 8 9 10 II 12 13 14 Throughput ( l i ters) 15 16 17 18 FIG. 10 BREAKTHROUGH CURVES FOR HAT CREEK AND CROWSNEST COALS TREATING A 0.7mg/liter SOLUTION OF COPPER. oo 39 I t was found that decreasing the adsorbate temperature to 15°C from 23°C produced no s i g n i f i c a n t change i n the coal's removal capacity. A t e s t was performed with a l l operating parameters except temperature the same as i n te s t 1. The decreased temperature increased the capacity of the coal by about 2%. This difference can be explained by experimental error. 3.3.3 Copper Removal - Crowsnest Coal The tests numbered 9 to 12 i n Table IV were performed using Crowsnest coal f or the purpose of comparing Hat Creek and Crowsnest coal i n column operation. The breakthrough curve f o r Test 9 i s compared i n Figure 11 to the Hat Creek break-through curve, which was obtained under i d e n t i c a l conditions. As shown i n Table I I I the capacity of Hat Creek coal i s greater than that of Crowsnest coal by a f a c t o r ranging between 1.5 and 2. This observation i s i n l i n e with the trends found during the batch t e s t s . Figure 12 shows that increasing the flow rate through a column of Crowsnest coal decreases the capacity of the column and that Crowsnest coal has a l e s s e r capacity than Hat Creek 2 coal f o r copper ions at equal flow rates of 5 g a l / f t /min. The decrease i n capacity caused by increasing the flow rate was approximately 60% i n the case of Crowsnest coal compared with only a 20% decrease i n the case of Hat Creek coal (Table I I I ) . Throughput volume in liters FIG. II BREAKTHROUGH CURVES FOR HAT CREEK AND CROWSNEST COALS, INFLUENT CONCENTRATION lOOmg/liter COPPER. o Crowsnest cool 5gal./ft.2/min. Crowsnest coal lgal./ft2/min. / r tf / Hat Creek coal 5gal./ft2/min. Influent pH 5 Depth of coal I ft. Wt. of coal 32gm Grain size 28/48 1.0 2.0 Throughput volume in liters 3.0 FIG. 12 BREAKTHROUGH CURVES FOR CROWSNEST COAL,SHOWING E F F E C T S OF FLOW R A T E . 42 The use of Hat Creek coal o f f e r s two advantages over the use of Crowsnest coal f o r copper removal. Hat Creek c o a l , i n addition to having a higher capacity than Crowsnest coal , i s also l e s s a f f e c t e d by changes i n flow rates. The l a t t e r point may be important i n i n d u s t r i a l s i t u a t i o n s where unsteady flow rates occur. Figure 9 shows a comparison of breakthrough curves f or the two coals t r e a t i n g an adsorbate of 10 mg/l copper. These curves show that both coals can e f f e c t 99% removal of copper from the 10 mg/l s o l u t i o n . The Crowsnest column i s exhausted before the Hat Creek column, again i n d i c a t i n g that Hat Creek coal i s superior to Crowsnest coal f o r t r e a t i n g solutions containing copper. Crowsnest coal, l i k e Hat Creek coal, had the a b i l i t y to decrease the concentration of a 0.7 mg/l copper s o l u t i o n to a value less than 0.05 mg/l. The p l o t of concentration vs. throughput i s shown i n Figure 10. No v a l i d conclusions can be drawn with respect to the capacity of the two coals t r e a t i n g the 0.7 mg/l s o l u t i o n as the tests were not run u n t i l breakthrough. However, i t i s obvious that very high q u a l i t y e f f l u e n t s are possible when tr e a t i n g d i l u t e solutions containing copper with e i t h e r Hat Creek or Crowsnest c o a l . 3.3.4 Removal of Lead - Hat Creek coal Hat Creek coal was capable of e f f e c t i v e l y removing lead ions 43 from a lead n i t r a t e s o l u t i o n f o r a f i n i t e time period during a column t e s t . The test i s described i n Table I I I , and the breakthrough curve i s shown i n Figure 13. The coal, which was capable of removing 99% of the lead from a 300 mg/l lead n i t r a t e s o l u t i o n f o r approximately two l i t e r s of throughput, had a capacity f or lead ions of 22.5 mg/gm and 24 mg/gm for breakthrough concentrations of 10% and 50% of i n f l u e n t , r e s p e c t i v e l y . 3.3.5 Removal of Heavy Metal Mixture A test was performed to examine the a b i l i t y of Hat Creek coal to remove a v a r i e t y of heavy metals mixed i n s o l u t i o n . A l l v a r i a b l e s , except impurity type and concentration, were the same as those used i n Test Number One (Table I I I ) . The metals and the i n f l u e n t concentrations were a r b i t r a r i l y chosen as follows: Copper - 2.3 mg/l Lead - 4.0 mg/l Zinc - 1.8 mg/l Nick e l - 2.0 mg/l Cadmium - 2.6 mg/l I t was observed that the coal removed almost a l l the metal contained i n a two l i t e r sample of mixture passed through the column. The concentrations of the metals i n the ef f l u e n t were too low (<0.05 mg/l) to be measured by the atomic absorption spectrophotometer without using concentration techniques. (These techniques were not performed because 2 2 0 r ^ 2 0 0 CP J 180 o I60| | 140 c <D 0 120 c ° IOO 1 80 £ 60 4 0 2 0 0 Coal type Grain size Flow rate Coal depth Weight of coal Hat Creek 28/48 I gal. /ft./min I ft. 32gm Influent concentration 300mg/liter Lead 1.0 2 .0 Throughput volume in liters 3.0 4.0 FIG. 13 BREAKTHROUGH CURVE FOR HAT CREEK C O A L , SHOWING CAPACITY FOR LEAD 45 the test was meant to be more q u a l i t a t i v e than quantitative.) 3.3.6 Regeneration I t was observed that by leaving the coal at rest f o r a period subsequent to column breakthrough, a renewed capacity f o r adsorption was r e a l i z e d . Figure 14 shows the sequential breakthrough curves of Hat Creek and Crowsnest coals t r e a t i n g a 10 mg/1 s o l u t i o n of copper. The figu r e shows c l e a r l y that both coals exhibit a further capacity when l e f t submerged i n the wastewater f or two days. In general, i t was found that: (i ) The renewed capacity of Hat Creek coal i s greater than that of Crowsnest coal. ( i i ) The minimum e f f l u e n t concentration i s higher a f t e r the two day period than at the beginning of the previous run. ( i i i ) The breakthrough curves become steeper a f t e r each two day " r e s t " period. (iv) The a d d i t i o n a l capacity obtained by two days of being submerged i n wastewater decreases with the number of times the process i s repeated. The capacity of Hat Creek coal was increased by approximately 35% by allowing a two day break a f t e r the column was run to a 20% breakthrough concentration. The cause of th i s phenomenon i s not understood at the present time. 1 1 er 10 9 cn E 8 Cu 7 ion 6 -4— D 5 — C <D 4 O C CO 3 c 2 <u » * — 1 LU Influent concentration Cu = 9.9 mg/liter pH = 5.8 0 Crowsnest coal 28/48 32 gm flow rate = 5gal./ftc/min. NOTE VERTICAL LINES DENOTE 2 DAY PERIODS WHEN COAL WAS SUBMERGED BUT NO FLOW WAS TAKING P L A C E . 12 14 16 18 20 22 24 26 28 30 32 34 36 38 Throughput volume in l i ters i 4 0 FIG. 14 BREAKTHROUGH CURVES FOR HAT CREEK AND CROWSNEST COALS TREATING A 10 mg / liter SOLUTION OF COPPER. 47 3.3.7 Beef Extract Removal Column tests performed on a beef extract s o l u t i o n showed that both coals were i n e f f i c i e n t and of low capacity when removing beef extract on a continuous b a s i s . An o u t l i n e of the tests i s shown i n Table I I I , Tests 14 and 15. The breakthrough curves for the test are shown i n Figure 15. Both e f f l u e n t concentrations s t a r t to increase immediately. Within 0.2 l i t e r s of throughput, the e f f l u e n t concentration of the Hat Creek column has reached 40% of i n f l u e n t and the e f f l u e n t concentration of the Crowsnest column has reached 70% of i n f l u e n t . Neither column i s capable of producing even 50% removal for a throughput of 1 l i t e r . The capacities of coal i n the columns were calculated and are shown i n Table I I I . The table shows that Hat Creek coal has a higher capacity f o r beef extract. I f a high q u a l i t y e f f l u e n t i s required, however, the capacity i s zero f o r a l l p r a c t i c a l purposes. 3.3.8 Phosphate Removal Phosphate removal on a continuous basis was tested by using a s o l u t i o n of Na^PO^. The concentration of phosphorus was 10 mg/1 as P. The other test parameters were the same as those i n the t e s t s f o r Beef Extract Removal. It was found that neither coal measurably removed phosphorus 81? 49 from s o l u t i o n . Shannon [2] i n a s i m i l a r experiment also found that coal would not adsorb phosphates from s o l u t i o n . The Rand ' Corporation [3] obtained phosphate removals of up to 40% when operating a 10,000 gpd p i l o t plant t r e a t i n g secondary e f f l u e n t . The report stated, however, that a large p o r t i o n of t h i s removal was probably due to f i l t e r i n g of suspended s o l i d s rather than adsorption. 3.3.9 Summary of Column Tests Both Hat Creek and Crowsnest coal e f f e c t i v e l y removed heavy metals from s o l u t i o n during column operation. The Hat Creek coal was found to be superior to Crowsnest coal with respect to ultimate removal capacity and a b i l i t y to treat solutions at high flow rates. Increasing the grain s i z e of c o a l , decreasing pH and increasing flow rate a l l had the e f f e c t of decreasing the capacity of a coal column to treat a copper s o l u t i o n . Temperature did not seem to have an e f f e c t on column operation. Greater than 99% removal of heavy metals was p o s s i b l e . f o r f i n i t e periods of time with solutions as d i l u t e as 0.7 mg/l or as concentrated as 100 mg/l. Capacity of the Hat Creek coal f o r copper ions was approximately 0.5 to 1% by weight of the coal and for lead ions was about 2% by weight of the coal. I f , a f t e r a coal column was exhausted i t was allowed to remain submerged i n the wastewater already 50 i n the column for 2 days a renewed capacity of approximately 35% of the o r i g i n a l capacity was r e a l i z e d . This e f f e c t was more pronounced with Hat Creek coal. Neither coal produced a high q u a l i t y e f f l u e n t from a beef extract s o l u t i o n during the column t e s t s , even though the batch tests predicted that some adsorption of organics would occur. Neither coal removed any phosphorus from a sodium phosphate s o l u t i o n . The column tests were designed from batch test data and were simple and convenient to run. A l l runs were terminated within, about 14 hours as required and hence designed f o r , using batch test data. In general the trends noticed i n the batch tests with respect to the e f f e c t s of coal type, grain s i z e and impurity type were also noticed i n the column t e s t s . C H A P T E R IV POSSIBLE USES 4.1 Industrial Heavy Metal Removal Heavy metals are present in the effluents of metal finishing industries, mine concentrators and sanitary l a n d f i l l leachates. The use of coal could be an effective means of treating these effluents. Wastewater from the sources mentioned may contain metals in one or more of the following forms: (i) Ionic - metals dissolved in true solution (or, more correctly, complexed with water molecules), (i i ) Complexed - with compounds such as cyanide or natural organics. ( i i i ) Suspended - in the form of insoluble metal compounds. The results of this and other studies show that coal has the potential to remove metals in a l l three forms mentioned above. The weight of coal required to treat 1,000 gallons of a 10 mg/1 solution of copper to an average effluent concentration of 0.2 mg/1 (breakthrough concentration 1.0 mg/1) was calculated to be 20 lbs. as follows: 51 52 Cap. of coal (Table III) =5.3 mg/gm = 0.53% by wt. of coal = 1,000 gallons = 10,000 l b . = 10 mg/l = 10 lb/106 l b s . = 10 lb/106 l b . x lO^ l b . = 0.1 l b s . = 0.1 l b . x 100 Vol. of wastewater Wt. of wastewater Concentration of Copper Wt. of Copper Weight of coal required 0.53% = 20 l b s . At an assumed coal cost of $15/Ton, the cost of coal required for t r e a t i n g 1,000 gallons of 10 mg/l copper waste would be approxi-mately $0.15. I t must be noted, however, that the above c a l c u l a t i o n i s preliminary as i t assumes that a l l the coal w i l l be i n a u s e f u l form a f t e r grinding. In actual f a c t , there w i l l be a loss of f i n e s i n grinding. Further t e s t s are required to see i f t h i s loss i s s i g n i f i c a n t . More research i s required as to the economics of the process, before a reasonable cost comparison can be made with conventional treatment processes. 4.2 Treatment of Municipal Sewage The poor removals of beef extract measured i n t h i s study i n d i c a t e that neither Hat Creek nor Crowsnest coal have s u f f i c i e n t adsorptive properties to enable them to be used e f f e c t i v e l y i n an adsorptive process t r e a t i n g domestic sewage. Furthermore, the n e g l i g i b l e removal of sodium phosphate indicates that the effectiveness of coal i n t r e a t -ing a waste containing inorganic phosphate using conventional adsorp-t i o n treatment processes would be very low. Therefore, the use of the coals tested i s not recommended for the treatment of municipal 53 waste or secondary e f f l u e n t by an adsorption process when e i t h e r removal of organic materials or inorganic phosphate i s required. There i s the p o s s i b i l i t y , as mentioned i n the previous s e c t i o n , that treatment of heavy metals present from i n d u s t r i a l sources i n municipal sewage could be e f f e c t e d by a coal process, but the economics of such a process, require further study. The fact that neither coal tested i n t h i s study was s u i t a b l e fo r use i n adsorption processes does not preclude t h e i r use i n other waste treatment processes. For example, coal could be used as a f i l t e r medium or as a medium to support b i o l o g i c a l growth and so e f f e c t a c e r t a i n degree of treatment on a municipal waste. However, use of coal i n such circumstances should be preceded by an economic comparison between coal and other a v a i l a b l e f i l t e r and b i o l o g i c a l t r i c k l i n g f i l t e r media. C H A P T E R V CONCLUSIONS AND RECOMMENDATIONS 5.1 Conclusions The conclusions of the study are as follows: (i) Both Hat Creek and Crowsnest coal had the ab i l i t y to effectively remove heavy metal from solution, ( i i ) The capacity of 28/48 grain size Hat Creek coal for removal of copper ions was approximately 0.5% to 1% of the weight of the coal. This capacity was measured using column tests. ( i i i ) Hat Creek coal had the abi l i t y to remove 99% of copper from influent waste streams containing as l i t t l e as 0.7 mg/l Cu and as much as 100 mg/l Cu. Effluent concentra-tions lower than 0.05 mg/l were recorded, (iv) Crowsnest coal also had the abil i t y to remove high per-centages of copper from solution but i t s ultimate capacity for removal of metal ions was less than that of Hat Creek coal. The capacity of Crowsnest coal for copper ions was approximately 0.2% to 0.5% by weight of the coal, (v) Decreasing the grain size of Hat Creek coal in the column operation increased the capacity of the coal. The increase in capacity for copper ions using 48/65 coal instead of 14/28 coal was approximately 50%. 54 55 (vi) Increasing flow rate through the columns had the e f f e c t of decreasing the capacity of both Hat Creek and Crowsnest coal f o r removal of copper ions. A f i v e f o l d increase i n flow rate decreased the unit capacity of Hat Creek coal by 20% and Crowsnest by 60%. ( v i i ) Decreasing i n f l u e n t pH to 2 had the e f f e c t of greatly decreasing the capacity of Hat Creek coal for removal of copper ions. ( v i i i ) The capacity of Hat Creek coal for removing copper ions was not decreased when the i n f l u e n t copper concentration was reduced from 100 mg/1 to 10 mg/1. (ix) Hat Creek coal was successful i n removing to amounts less than 0.05 mg/1 f o r a short time run, the following metals mixed i n s o l u t i o n : copper, zi n c , lead, cadmium, and n i c k e l , (x) I f a Hat Creek coal column i s exhausted of i t s heavy metal removal capacity, and i f the coal i s l e f t submerged f o r two days i n the wastewater present i n the column at shutdown, then a renewed capacity for heavy metal removal i s made av a i l a b l e . This renewed capacity can amount to approximately 35% of the o r i g i n a l removal capacity. A Crowsnest coal column w i l l e x h i b it the same properties, but the increase i n capacity to be gained i s not as much as that gained by a Hat Creek coal column, (xi) Neither coal was able to produce a good q u a l i t y e f f l u e n t from a beef extract s o l u t i o n during the column t e s t s . This i s i n agreement with other studies (2). 56 ( x i i ) Neither coal was able to measurably remove any phosphate from a sodium phosphate s o l u t i o n during the column t e s t s . ( x i i i ) Observations made throughout the study indicated that a mechanism other than p r e c i p i t a t i o n and subsequent f i l t r a -t i o n was responsible f o r the removal of heavy metals from s o l u t i o n . Conceivably, coal could be used to p u r i f y e f f l u e n t s containing heavy metals from metal f i n i s h i n g i n d u s t r i e s , mining operations, sanitary l a n d f i l l s or i n d u s t r i a l i z e d m u n i c i p a l i t i e s . I t was c a l -culated that a waste stream containing 10 mg/1 copper could be treated to an average concentration of 0.2 mg/1 with a coal consump-t i o n of approximately 20 lbs of coal/1000 gallons of water. Assuming a coal cost of $15/ton, the cost per 1000 gallons of wastewater treated, for the coal used i n treatment would be approximately $0.15. The r e s u l t s of the tests performed using beef extract and sodium phosphate solutions indicated that coal would not be p a r t i c u l a r l y e f f e c t i v e i n removing ei t h e r phosphates or oxygen demanding materials from municipal sewage. 5.2 Recommendations (i ) Several B r i t i s h Columbia coals should be tested to f i n d which coals are the most e f f e c t i v e i n removal of heavy metals, ( i i ) The f e a s i b i l i t y of regenerating the coal should be investigated, ( i i i ) E f f e c t s of flow rate, pH, grain s i z e and i n f l u e n t concentration of impurity should be studied i n more d e t a i l using lab scale 57 column t e s t s . (iv) The types and amounts of materials added by the coals to the wastewater should be determined. Such additions could make the e f f l u e n t impossible f or re-use i n d u s t r i a l l y , (v) Determination of the technical and economic f e a s i b i l i t y of procurement and disposal of coal should be c a r r i e d out. (vi) P i l o t scale t e s t i n g of the most e f f e c t i v e coals on actual wastewaters should be undertaken. GLOSSARY OF TERMS mg/l - m i l l i g r a m s / l i t e r wt - dry weight breakthrough curve p l o t of e f f l u e n t concentration vs volume of throughput i n a column test breakthrough concentration that concentration of e f f l u e n t from a column operation which necessitates that the column be replaced. batch test a t e s t of the capacity of coal to remove an impurity from wastewater under non-flow-through conditions column test a test of the capacity of coal to remove an impurity from wastewater under flow-through conditions average e f f l u e n t concentration the t o t a l weight of impurity passed through a column divided by the t o t a l hydraulic throughput adsorption the removal of impurities from s o l u t i o n by a p h y s i c a l adsorption, chemical adsorp-t i o n or ion exchange process B.O.D. Biochemical Oxygen Demand C.O.D. - Chemical Oxygen Demand TKN - Total Kjeldahl Nitrogen 58 BIBLIOGRAPHY 1. G.E. Johnson and L.M. Kunka, "The Use of Coals as Adsorbents for Removing Organic Contaminants from Wastewater", U.S. Dept. of the I n t e r i o r , Bureau of Mines, Report of Investigation 6884, U.S. Government P r i n t i n g O f f i c e , Washington, D.C. 2. E. Shannon, "The Use of Coal as an Adsorbent f or the Treatment of Wastewaters", M. Sc. th e s i s , University of Waterloo, Waterloo, Ontario, (1967). 3. "Development of a Coal Based Sewage Treatment Process", O f f i c e of Coal Research, U.S. Dept. of the I n t e r i o r , U.S. Government P r i n t i n g O f f i c e , Washington, D.C. (1972). 4. CH. Hinrichs, Grant A p p l i c a t i o n , U.S. P u b l i c Health Service, L i n f i e l d Research I n s t i t u t e , McMinnville, Oregon (1971). 5. J.B. Porter and R.J. Durley, "An Investigation of the Coals of Canada with Reference to Their Economic Q u a l i t i e s " , Canada Department of Mines, Government P r i n t i n g Bureau, Ottawa, (1912). 59 APPENDIX I TYLER MESH SERIES 60 MESH SIZE 14 28 48 65 SCREEN OPENING (MM) 1.2 0.6 0.3 0.2 APPENDIX II SAMPLE DETERMINATION OF COAL CAPACITY FROM A BREAKTHROUGH CURVE 63 Influent concentration lOOmg/liter 0 1.0 E 2.0 Throughput volume in liters Choose breakthrough concentration Mg of impurity removed Mg of impurity removed/gm of coal Average effluent concentration 10% of influent or 10 mg/l Area ABCDA 147 mg of Cu 147 mg/32 gm 4.3 mg/gm Weight of impurity passed through column divided by throughput Area ABEA/throughput 3.36 mg per 1.4 1 2.4 mg/l APPENDIX III BATCH TEST DATA 64 B a t c h T e s t D a t a I n i t i a l C o n c e n t r a t i o n o f i m p u r i t y ( m g / l ) . I n i t i a l w e i g h t o f i m p u r i t y (mg) F i n a l C o n c e n t r a t i o n o f i m p u r i t y ( m g / l ) F i n a l w e i g h t o f i m p u r i t y (mg) W e i g h t , o f i m p u r i t y r e m o v e d (mg) D o s a g e o f c o a l (mg) W t . o f i m p u r i t y r e m o v e d /gm o f c o a l (mg/gm) 9 2 5 9 2 . 5 5 1 5 5 1 . 5 4 1 5 . 0 8 . 2 4 6 0 46 1 6 5 1 6 . 5 2 9 . 5 4 . 0 7 . 4 2 1 0 2 1 54 5 - 4 15 . 6 2 . 0 7 . 8 1 6 1 1 6 . 1 39 3 . 9 1 2 . 2 2 . 0 6 . 1 90 9 . 0 20 2 . 0 7 . 0 2 . 0 3 . 5 46 4 . 6 14 1 . 4 3 . 2 2 . 0 1 . 6 2 0 2 . 0 2 . 2 0 . 2 1 . 8 2 . 0 0 . 9 C o p p e r ' A d s o r b a t e H a t C r e e k C o a l 2 8 / 4 8 G r a i n S i z e 24 h r . c o n t a c t t i m e . ON B a t c h T e s t D a t a I n i t i a l C o n c e n t r a t i o n o f i m p u r i t y (mg/1) I n i t i a l w e i g h t o f i m p u r i t y (mg) F i n a l C o n c e n t r a t i o n o f i m p u r i t y ( m g / 1 ) F i n a l w e i g h t o f i m p u r i t y (mg) W e i g h t o f i m p u r i t y r e m o v e d (mg) D o s a g e o f c o a l (mg) W t . o f i m p u r i t y r e m o v e d /gm o f c o a l (mg/gm) 5 0 0 5 0 i 3 3 0 33 17 1 . 0 1 7 2 0 0 20 1 2 6 1 2 . 6 7 . 4 0 . 5 1 4 . 8 1 0 0 10 42 4 . 2 5 . 8 0 . 5 1 1 . 6 5 2 5 . 2 10 1 . 0 4 . 2 0 . 5 8 . 4 20 2 . 0 2 . 8 0 . 3 1 . 7 0 . 5 3 . 4 C o p p e r A d s o r b a t e H a t C r e e k C o a l 4 8 / 6 5 G r a i n S i z e 24 h r . c o n t a c t t i m e B a t c h T e s t D a t a I n i t i a l l o n c e n t r a t i o n o f i m p u r i t y (mg/1) I n i t i a l w e i g h t o f i m p u r i t y (mg) F i n a l C o n c e n t r a t i o n ' o f i m p u r i t y ( m g / 1 ) F i n a l w e i g h t o f i m p u r i t y (mg) W e i g h t o f i m p u r i t y r e m o v e d (mg) D o s a g e o f c o a l (mg) W t . o f i m p u r i t y r e m o v e d /gm o f c o a l (mg/gm) 6 2 2 6 2 . 2 4 9 0 49 1 3 . 2 4 . 0 3 . 3 1 9 0 19 1 2 0 12 7 2 . 0 3 . 5 90 9 . 0 42 4 . 2 4 . 8 2 . 0 2 . 4 90 9 . 0 40 4 . 0 5 . 0 2 . 0 2 . 5 46 4 . 6 16 1 . 6 3 . 0 2 . 0 1 . 5 20 2 . 0 1 . 0 0 . 1 1 . 9 2 . 0 0 . 9 20 2 . 0 1 . 0 0 . 1 1 . 9 2 . 0 0 . 9 C o p p e r A d s o r b a t e C r o w s n e s t C o a l 2 8 / 4 8 G r a i n S i z e 24 h r . c o n t a c t t i m e B a t c h T e s t D a t a I n i t i a l C o n c e n t r a t i o n o f i m p u r i t y ( m g / l ) I n i t i a l w e i g h t o f i m p u r i t y (mg) F i n a l C o n c e n t r a t i o n o f i m p u r i t y ( m g / l ) F i n a l w e i g h t o f i m p u r i t y (mg) W e i g h t o f i m p u r i t y r e m o v e d (mg) D o s a g e o f c o a l (mg) W t . o f i m p u r i t y r e m o v e d /gm o f c o a l (mg/gm) 5 0 0 5 0 3 9 0 39 1 1 1 . 0 11 3 3 5 3 3 . 5 ' 2 0 5 2 0 . 5 1 3 1 . 0 1 3 2 0 0 20 1 5 0 15 5 0 . 5 10 59 5 . 9 18 1 . 8 4 . 1 0 . 5 8 . 2 5 0 5 1 0 . 8 1 . 1 3 . 9 0 . 5 7 . 8 4 5 4 . 5 2 . 0 0 . 2 4 . 3 1 . 0 4 . 3 C o p p e r A d s o r b a t e C r o w s n e s t C o a l 4 8 / 6 5 G r a i n S i z e 24 h r . c o n t a c t t;Lme B a t c h T e s t D a t a I n i t i a l C o n c e n t r a t i o n o f i m p u r i t y (mg/1) I n i t i a l w e i g h t o f i m p u r i t y (mg) F i n a l C o n c e n t r a t i o n ' o f i m p u r i t y ( m g / 1 ) F i n a l w e i g h t o f i m p u r i t y (mg) W e i g h t o f i m p u r i t y r e m o v e d (mg) D o s a g e o f c o a l (mg) W t . o f i m p u r i t y r e m o v e d /gm o f c o a l (mg/gm) 1 0 0 0 1 0 0 1 2 2 0 2 2 . 0 78 2 . 0 39 5 0 0 5 0 1 6 5 1 6 . 5 3 3 . 5 1 . 0 33 5 0 0 5 0 35 3 . 5 4 6 . 5 2 . 0 2 3 20Q 20 3 . 0 0 . 3 1 9 . 7 2 . 0 1 0 2 0 0 20 3 . 0 0 . 3 1 9 . 7 2 . 0 10 1 0 0 10 1 . 0 0 . 1 9 . 9 2 . 0 5 5 0 5 . 0 0 . 5 0 . 5 5 2 . 0 2 L e a d A d s o r b a t e H a t C r e e k C o a l 2 8 / 4 8 G r a i n S i z e 24 h r . c o n t a c t t i m e B a t c h T e s t D a t a I n i t i a l C o n c e n t r a t i o n o f i m p u r i t y (mg/1) ' I n i t i a l w e i g h t o f i m p u r i t y (mg) F i n a l C o n c e n t r a t i o n o f i m p u r i t y ( m g / 1 ) F i n a l w e i g h t o f i m p u r i t y (mg) W e i g h t o f i m p u r i t y r e m o v e d (mg) D o s a g e o f c o a l (mg) W t . o f i m p u r i t y r e m o v e d /gn o f c o a l (mg/gm) 20 2 . 0 0 . 5 0 . 5 2 2 . 0 1 5 4 0 54 3 1 4 3 1 . 4 2 2 . 6 0 . 5 45 5 4 0 54 3 1 0 3 1 . 0 23 .0 0 . 5 4 6 5 4 0 54 2 3 4 2 3 . 4 3 0 . 6 0 . 75 4 1 5 4 0 54 1 8 0 18 36 1 . 0 36 5 4 0 54 1 7 6 1 7 . 6 3 6 . 4 1 . 0 36 5 4 0 54 70 7 47 1 - 5 30 L e a d A d s o r b a t e H a t C r e e k C o a l 2 8 / 4 8 G r a i n S i z e 24 h r . c o n t a c t t i m e B a t c h T e s t D a t a I n i t i a l C o n c e n t r a t i o n o f i m p u r i t y ( m g / l ) I n i t i a l w e i g h t o f I m p u r i t y (mg) F i n a l C o n c e n t r a t i o n o f i m p u r i t y ( m g / l ) F i n a l w e i g h t o f i m p u r i t y (mg) W e i g h t o f i m p u r i t y r e m o v e d (mg) D o s a g e o f c o a l (mg) W t . o f i m p u r i t y r e m o v e d /g o f c o a l (mg/gm) 5 2 0 52 2 8 5 2 8 . 5 2 3 . 5 0 . 5 47 5 2 0 5 2 2 1 0 2 1 . 0 31 0 . 75 4 1 . 2 5 2 0 52 154 1 5 . 4 3 6 . 6 1 . 0 3 6 . 6 5 2 0 52 1 4 4 1 4 . 4 3 7 . 6 1 . 0 3 7 . 6 5 2 0 52 50 5 47 1 . 5 3 1 . 5 L e a d A d s o r b a t e H a t C r e e k C o a l 4 8 / 6 5 G r a i n S i z e 24 H r . c o n t a c t t i m e Batch Test Data I n i t i a l Concen t r a t i o n of impurity (mg/1) I n i t i a l weight of . impurity (mg) F i n a l Concentration of impurity (mg/1) Fi n a l weight of impuri ty (mg) Weight of impurity removed (mg) Dosage of coal (mg) Wt. of impurity removed /g of coal (mg/gm) 540 5 4.0 374 37.4 16.6 0.5 33 540 54.0 , 286 28.6 25.4 0.75 34 5 40 54.0 216 • 21.6 32. 4 1.0 32 540 54.0 240 24 30.0 1.0 30 540 54.0 104 • 10.4 43.6 1.5 29 500 50.0 4.0 0.4 49.6 2.0 25 200 20.0 1.0 0.10 19.9 2.0 10 100 10.0 0.5 0.05 10 2.0 5 50 5.0 0.5 0.05 5 2.0 2.5 20 2.0 0.1 0.001 2 2.0 1 Lead Adsorbate Crowsnest Coal 28/48 Grain Size 24 hr. contact time Batch Test Data I n i t i a l Concentration of impurity (mg/l) ' I n i t i a l weight of impurity (mg) 520 52.0 520 52.0 520 52.0 520 52.0 520 52.0 520 52.0 F i n a l Concentration of impurity (mg/l) F i n a l weight of impurity (mg) Weight of impurity removed (mg) Dosage of coal (mg) Wt. of impurity removed /gm of coal (mg/gm) 320 32.0 20 0.5 40 315 31.5 20.5 0.5 41 240 24.0 28 0.75 37 160 16.0 36 1.0 36 150 » 15.0 37 1.0 37 32 3.2 48.8 1.5 33 Lead Adsorbate Crowsnest Coal 48/65 Grain Size 24 hr. Contact time Batch Test Data I n i t i a l Concentration of impurity (mg/l) I n i t i a l weight of Impurity (mg) F i n a l Concentration of impurity (mg/l) F i n a l weight of impuri ty (mg) Weight of impurity removed (mg) Dosage of coal (mg) Wt. of impurity removed /gm of coal (mg/gm) 560 56 420 42 14 1.0 14 560 5 6 375 37. 5 18.5 1.5 12. 3 560 56 325 32. 5 23.5 2.0 11. 7 120 12 • 45 4.5 7.5 1 7.5 60 6.0 25 . 2.5 3.5 0.5 7.0 68 6 . 8 18 1.8 5.0 1 5.0 29 2.9 4.3 0.4 2.5 1 2.5 Zinc Adsorbate Crowsnest Coal Grain Size 48/65 24 hr. contact time 3 Batch Test Data I n i t i a l Concentration of impurity (mg/1) I n i t i a l weight of impurity (mg) F i n a l Concentration of impurity (mg/1) F i n a l weight of impurity (mg) Weight of impurity removed (mg) Dosage of coal (mg) Wt. of impurity removed /gm of coal (mg/gm) 560 56 460 46 10 1.0 10 560 56 430 43 13 1.5 8.7 560 56 390 39 17 2.0 8.5 276 27.6 150 15.0 12.6 2.0 6.3 255 25.5 90 . 9.0 16.5 4.0 4.1 27.5 2. 75 3.5 0.35 2.4 2.0 1.2 Zinc Adsorbate Corwsnest Coal Grain Size 48/65 24 hr. contact time «-4 U l B a t c h T e s t D a t a I n i t i a l C o n c e n t r a t i o n o f i m p u r i t y ( m g / l ) I n i t i a l w e i g h t o f i m p u r i t y (mg) F i n a l C o n c e n t r a t i o n o f i m p u r i t y ( m g / l ) F i n a l w e i g h t o f i m p u r i t y (mg) W e i g h t o f i m p u r i t y r e m o v e d (mg) D o s a g e o f c o a l (mg) W t . o f i m p u r i t y r e m o v e d / g n o f c o a l (mg/gm) 2 5 6 2 5 . 6 1 9 7 1 9 . 7 ' 5 . 9 1 . 2 4 B 1 5 7 1 5 . 7 1 1 3 1 1 . 3 1 4 . 4 1 . 0 4 . 4 78 7 . 8 46 4 . 6 3 . 2 1 . 0 3 . 2 43 4 . 3 19 1 • 9 2 . 4 1 . 0 2 . 4 24 2 . 4 6 0 . 6 1 . 8 1 . 0 1 . 8 B e e f e x t r a c t a d s o r b a t e H a t C r e e k C o a l 4 8 / 6 5 G r a i n S i z e . 24 h r . c o n t a c t t i m e Batch Test Data I n i t i a l Concentration of impurity (mg/l) I n i t i a l weight of impurity (mg) F i n a l Concentration of impurity (mg/l) F i n a l weight of impurity (mg) Weight of impurity removed (mg) Dosage of coal (mg) y Wt. of impurity removed / g m of coal (mg/gm) 255 . 25.5 224 2 2.4 3.1 1.0 3.1 150 15 125 12.5 2.5 1.0 2.5 73 7.3 56 5.6 1.7 1.0 1.7 34 3.4 21 2.1 1.3 1.0 1.3 20. 5 2.0 8.0 0.8 1.2 1.0 1.2 Beef extract adsorbate Hat Creek Coal 48/65 Grain Size 24 hr. contact time Batch Test Data I n i t i a l Concentration of impurity (mg/1) I n i t i a l weight of impuri ty (mg) F i n a l Concentration of impurity (mg/1) Fi n a l weight of impurity (mg) Weight of impurity removed (mg) Dosage of coal (mg) Wt. of impurity removed /gi of coal (mg/gm) 255 25.5 240 24 1.5 1.0 1.5 150 15 136 13.6 1.4 1.0 1.4 73 7.3 63.5 6.3 1.0 1.0 1.0 34 3.4 26.5 2.7 0.7 1.0 0.7 20.5 2.0 10.5 1.0 1.0 1.0 1.0 Beef extract adsorbate Crowsnest Coal 48/65 Grain Size 24 hr. contact time I n i t i a l Concentration of impurity (mg/l) I n i t i a l weight of imp u r i ty (mg) F i n a l Concentration of impurity (mg/l) F i n a l weight of impuri ty (mg) Weight of impurity removed (mg) 100 100 75 75 50 50 30 20 20 10 5 5 3. 75 3. 75 2.5 2.5 1.5 1.0 1.0 0.5 87.5 90 62 64 33 41 20 12 8 5 4.37 4.5 3.1 3.2 1.65 2.05 1.0 0. 6 0.4 0.25 0.63 0.5 0.65 0.55 0.85 0.45 0.5 0.4 0. 6 0.25 . Phosphate Adsorbate Hat Creek Coal 28/48 Grain Size-Contact time 24 hrs. 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.831.1-0050516/manifest

Comment

Related Items