The role of sulphate reduction on the reductive decolorization of the azo dye reactive orange 14
The aim of this study was to investigate the impact of a broad range of sulphate concentrations (0-10 g SO super(-) sub(4) super(2) L super(-1)) on the reduction of an azo dye (reactive orange 14 (RO14)) by an anaerobic sludge. An increase in the sulphate concentration generally stimulated the reduc...
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Published in | Water Science & Technology Vol. 54; no. 2; pp. 171 - 177 |
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Main Authors | , , , , |
Format | Journal Article Conference Proceeding |
Language | English |
Published |
London
IWA Publishing
01.01.2006
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Subjects | |
Online Access | Get full text |
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Summary: | The aim of this study was to investigate the impact of a broad range of sulphate concentrations (0-10 g SO super(-) sub(4) super(2) L super(-1)) on the reduction of an azo dye (reactive orange 14 (RO14)) by an anaerobic sludge. An increase in the sulphate concentration generally stimulated the reduction of RO14 by sludge incubations supplemented with glucose, acetate or propionate as electron donor. Sulphate and azo dye reductions took place simultaneously in all incubations. However, there was a decrease on the rate of decolorization when sulphate was supplied at 10g SO super(-) sub(4) super(2) L super(-1). Abiotic incubations at different sulphide concentrations (0-2.5 g sulphide L super(-1)) promoted very poor reduction of ROM. However, addition of riboflavin (20 mu M), as a redox mediator, accelerated the reduction of RO14 up to 44-fold compared to a control lacking the catalyst. Our results indicate that sulphate-reduction may significantly contribute to the reduction of azo dyes both by biological mechanisms and by abiotic reductions implicating sulphide as an electron donor. The contribution of abiotic decolorization by sulphide, however, was only significant when a proper redox mediator was included. Our results also revealed that sulphate-reduction can out-compete with azo reduction at high sulphate concentrations leading to a poor decolorising performance when no sufficient reducing capacity is available. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 ObjectType-Article-2 ObjectType-Feature-1 SourceType-Books-1 ObjectType-Book-1 content type line 25 ObjectType-Conference-2 SourceType-Conference Papers & Proceedings-2 ObjectType-Conference-1 ObjectType-Feature-3 SourceType-Scholarly Journals-2 ObjectType-Conference Paper-1 SourceType-Conference Papers & Proceedings-1 ObjectType-Article-3 |
ISBN: | 1843395797 9781843395799 |
ISSN: | 0273-1223 1996-9732 |
DOI: | 10.2166/wst.2006.501 |