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Anaerobic Biodegradation of Sterols Contained in Kraft Mill Effluents

Paper ID Volume ID Publish Year Pages File Format Full-Text
22125 43255 2007 5 PDF Available
Title
Anaerobic Biodegradation of Sterols Contained in Kraft Mill Effluents
Abstract

Bleached kraft mill requires large quantities of water and chemicals reactives and generates effluents containing active organic compounds. Specifically, hormonal changes in fish and their communities have been demonstrated, which could be attributed to endocrine-disrupting chemicals (EDCs) contained in kraft mill effluents. This chronic toxicity is attributable to extractive compounds, such as resin acids, sterols, and fatty acids. The goal of this work is to evaluate the methanogenic toxicity and anaerobic biodegradation of stigmasterol and β-sitosterol. A continuously anaerobic filter (AF) was used for the anaerobic biodegradation of stigmasterol and β-sitosterol. Three phases were evaluated. In phase I, an elementary chlorine-free bleached kraft mill effluent was fed to the reactor whereas in phases II and III, the effluent was supplemented with increasing stigmasterol and β-sitosterol concentrations. The AF displays high performance in biological oxygen demand (BOD5) removal (up to 94%); however, only 50% of the chemical oxygen demand (COD) was removed. Simultaneously, the AF system shows a great ability to remove β-sitosterols (77–100%) and stigmasterols (87–95%). No negative effect on the methanogenic activity inhibition was shown by β-sitoesterols and stigmasterol. However, a mixture of β-sitosterols and stigmasterols (ratio 1:1) caused a less than 10% reduction in methanogenic activity.

Keywords
anaerobic biodegradation; endocrine-disrupting chemicals; stigmasterols; β-sitosterols; methanogenic toxicity
First Page Preview
Anaerobic Biodegradation of Sterols Contained in Kraft Mill Effluents
Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Bioscience and Bioengineering - Volume 104, Issue 6, December 2007, Pages 476–480
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering