Enhanced biodegradation of hexachlorocyclohexane in upflow anaerobic sludge blanket reactor using methanol as an electron donor
Anaerobic dechlorination of technical grade hexachlorocyclohexane (THCH) was studied in a continuous upflow anaerobic sludge blanket (UASB) reactor with methanol as a supplementary substrate and electron donor. A reactor without methanol served as the experimental control. The inlet feed concentrati...
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Published in | Bioresource technology Vol. 99; no. 7; pp. 2594 - 2602 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Oxford
Elsevier Ltd
01.05.2008
[New York, NY]: Elsevier Ltd Elsevier Science |
Subjects | |
Online Access | Get full text |
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Summary: | Anaerobic dechlorination of technical grade hexachlorocyclohexane (THCH) was studied in a continuous upflow anaerobic sludge blanket (UASB) reactor with methanol as a supplementary substrate and electron donor. A reactor without methanol served as the experimental control. The inlet feed concentration of THCH in both the experimental and the control UASB reactor was 100
mg
l
−1. After 60 days of continuous operation, the removal of THCH was >99% in the methanol-supplemented reactor as compared to 20–35% in the control reactor. THCH was completely dechlorinated in the methanol fed reactor at 48
h HRT after 2 months of continuous operation. This period was also accompanied by increase in biomass in the reactor, which was not observed in the experimental control. Batch studies using other supplementary substrates as well as electron donors namely acetate, butyrate, formate and ethanol showed lower % dechlorination (<85%) and dechlorination rates (<3
mg
g
−1
d
−1) as compared to methanol (98%, 5
mg
g
−1
d
−1). The optimum concentration of methanol required, for stable dechlorination of THCH (100
mg
l
−1) in the UASB reactor, was found to be 500
mg
l
−1. Results indicate that addition of methanol as electron donor enhances dechlorination of THCH at high inlet concentration, and is also required for stable UASB reactor performance. |
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Bibliography: | http://dx.doi.org/10.1016/j.biortech.2007.04.057 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0960-8524 1873-2976 |
DOI: | 10.1016/j.biortech.2007.04.057 |