Anaerobic Degradation of Linear Alkylbenzene Sulfonates in Coastal Marine Sediments

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• 作者：Pablo A. Lara-Mart&iacute ; n ; Abelardo Gó ; mez-Parra ; Thorsten Kö ; chling ; José ; Luis Sanz ; Ricardo Amils ; Eduardo Gonzá ; lez-Mazo
• 刊名：Environmental Science & Technology
• 出版年：2007
• 出版时间：May 15, 2007
• 年：2007
• 卷：41
• 期：10
• 页码：3573 - 3579
• 全文大小：255K
• 年卷期：v.41,no.10(May 15, 2007)
• ISSN：1520-5851

文摘

This research shows for the first time the degradation oflinear alkylbenzene sulfonates (LAS) under anaerobicconditions, together with the presence of metabolites andthe identification of microorganisms involved in thisprocess. This compound is the most widely used surfactantand its main environmental concern is related to itspersistence in the absence of oxygen as LAS accumulatesin anaerobic sediments and sewage sludges. Laboratoryexperiments performed with anoxic marine sediments spikedwith 10-50 ppm of LAS demonstrated, however, that itsdegradation reached 79% in 165 days via the generation ofsulfophenyl carboxylic acids (SPCs). Almost all of theadded LAS (>99%) was found to be attached to the sedimentwhile the less hydrophobic SPCs were predominant insolution, as their concentration increased progressivelyup to 3 ppm during the full course of the experiment. Averagehalf-life for LAS has been estimated to be 90 days,although higher values should be expected when the LASconcentration exceeds 20 ppm, due to inhibition of themicrobial community. Sulfate-reducing and methanogenicactivities proved to be intense during the experiment.Several sulfate-reducing bacteria and firmicutes/clostridiahave been identified as possible candidates for effectingthis degradation. Our results imply that the persistence ofLAS in anoxic compartments, such as marine sediments,should be reconsidered when evaluating its environmentalrisk.