- Library Home /
- Search Collections /
- Open Collections /
- Browse Collections /
- UBC Theses and Dissertations /
- Effect of DTPA and hydrogen peroxide on activated sludge...
Open Collections
UBC Theses and Dissertations
UBC Theses and Dissertations
Effect of DTPA and hydrogen peroxide on activated sludge performance Larisch, Belinda Cornelia V.
Abstract
This work explores the behaviour of a standard biological treatment system when exposed to two of the most common residuals from novel bleaching processes: hydrogen peroxide and the chelant DTPA. The potential problems for an activated sludge biological treatment unit, from the introduction of a chelating agent and hydrogen peroxide, were anticipated to stem from the sequestering of vital trace elements by the chelant, and the oxidation of biomass by the hydrogen peroxide. Typical residual quantities from TCF bleaching processes are 0.875 g DTPA / L and 0.2 g H2O2 / L, although the peroxide residual concentration is variable, up to approximately 1 g/L. The effects of running a typical biological treatment system on effluent from novel bleaching processes were also determined, in addition to the effects of switching influent sources between novel and conventional bleaching effluent. Activated sludge secondary treatment systems could successfully treat elementally chlorine free (ECF) and totally chlorine free (TCF) bleached kraft mill effluents by achieving > 90% BOD removal, > 40 % COD removal, and 100% acute toxicity removal. Influent feed changes between untreated chlorine free bleaching effluent and conventional effluent (from a 60% ClO2 bleaching sequence) resulted in immediate changes in treatment efficiency. Switching from TCF to conventional effluent decreased BOD removal, whereas switching from ECF to conventional effluent increased BOD removal. The addition of DTPA and hydrogen peroxide was found to have significant effects on activated sludge treatment. Continuous treatment of peroxide-containing wastewater reduced floe density at peroxide concentrations greater than 200 - 500 mg/L, although treatment efficiency was maintained. Continuous treatment of DTPA containing wastewater resulted in BOD removal efficiencies of 60% at DTPA concentrations greater than 600 mg/L. The addition of both DTPA and peroxide at typical TCF bleached kraft mill effluent (BKME) residual concentrations caused biological treatment to cease entirely. Individually, the effects of hydrogen peroxide and DTPA were: the reduction of biomass metabolic activity at concentrations of 100 mg/L H2O2, and 500 mg/L DTPA, the induction of catalase activity upon H2O2 addition, and the release of cellular material due to cell wall damage at DTPA concentrations greater than 50 mg/L. [Scientific formulae used in this abstract could not be reproduced.]
Item Metadata
Title |
Effect of DTPA and hydrogen peroxide on activated sludge performance
|
Creator | |
Publisher |
University of British Columbia
|
Date Issued |
1998
|
Description |
This work explores the behaviour of a standard biological treatment system when
exposed to two of the most common residuals from novel bleaching processes: hydrogen
peroxide and the chelant DTPA. The potential problems for an activated sludge biological
treatment unit, from the introduction of a chelating agent and hydrogen peroxide, were
anticipated to stem from the sequestering of vital trace elements by the chelant, and the
oxidation of biomass by the hydrogen peroxide. Typical residual quantities from TCF
bleaching processes are 0.875 g DTPA / L and 0.2 g H2O2 / L, although the peroxide residual
concentration is variable, up to approximately 1 g/L.
The effects of running a typical biological treatment system on effluent from novel
bleaching processes were also determined, in addition to the effects of switching influent
sources between novel and conventional bleaching effluent. Activated sludge secondary
treatment systems could successfully treat elementally chlorine free (ECF) and totally chlorine
free (TCF) bleached kraft mill effluents by achieving > 90% BOD removal, > 40 % COD
removal, and 100% acute toxicity removal. Influent feed changes between untreated chlorine
free bleaching effluent and conventional effluent (from a 60% ClO2 bleaching sequence)
resulted in immediate changes in treatment efficiency. Switching from TCF to conventional
effluent decreased BOD removal, whereas switching from ECF to conventional effluent
increased BOD removal.
The addition of DTPA and hydrogen peroxide was found to have significant effects on
activated sludge treatment. Continuous treatment of peroxide-containing wastewater reduced
floe density at peroxide concentrations greater than 200 - 500 mg/L, although treatment
efficiency was maintained. Continuous treatment of DTPA containing wastewater resulted in
BOD removal efficiencies of 60% at DTPA concentrations greater than 600 mg/L. The addition
of both DTPA and peroxide at typical TCF bleached kraft mill effluent (BKME) residual
concentrations caused biological treatment to cease entirely.
Individually, the effects of hydrogen peroxide and DTPA were: the reduction of biomass
metabolic activity at concentrations of 100 mg/L H2O2, and 500 mg/L DTPA, the induction of
catalase activity upon H2O2 addition, and the release of cellular material due to cell wall damage
at DTPA concentrations greater than 50 mg/L. [Scientific formulae used in this abstract could not be reproduced.]
|
Extent |
9184340 bytes
|
Genre | |
Type | |
File Format |
application/pdf
|
Language |
eng
|
Date Available |
2009-07-03
|
Provider |
Vancouver : University of British Columbia Library
|
Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
|
DOI |
10.14288/1.0058648
|
URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
|
Graduation Date |
1999-05
|
Campus | |
Scholarly Level |
Graduate
|
Aggregated Source Repository |
DSpace
|
Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.