Long-Term Anaerobic Mineralization of Pentachlorophenol in a Continuous-Flow System Using Only Lactate as an External Nutrient

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• 作者：Zhiling Li ; Yasushi Inoue ; Daisuke Suzuki ; Lizhen Ye ; Arata Katayama
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2013
• 出版时间：February 5, 2013
• 年：2013
• 卷：47
• 期：3
• 页码：1534-1541
• 全文大小：370K
• 年卷期：v.47,no.3(February 5, 2013)
• ISSN：1520-5851

文摘

A simple anaerobic upflow column system (15 cm long, 5 cm inner diameter) for complete pentachlorophenol (PCP) mineralization has been established using a microbial consortium requiring only lactate as the external nutrient. With lactate as an electron donor, PCP was dechlorinated to 3-chlorophenol (3-CP) and phenol. The degradation of 3-CP and phenol proceeded without an external electron acceptor, indicating fermentative or syntrophic characteristics. A tracer experiment using ¹⁴C鈥揢-ring-labeled PCP confirmed the conversion of PCP into CO₂ (54.1%), CH₄ (48.1%), and biomass (0.6%). The nitrogen required for degradation was supplied by N₂-fixation, evidenced from the nitrogen balance and an acetylene reduction assay. A 16S rRNA gene library analysis showed that bottom of the upflow column harbored the potential dechlorinators, Dehalobacter and Desulfitobacterium, and the phenol/3-CP fermentative or syntrophic degraders, Cryptanaerobacter and Syntrophus. The nitrogen-fixing facultative anaerobes, Rhizobiales, were detected in the top of the upflow column, with other possible nitrogen-fixers at both bottom and top of the upflow column. The mineralization rate reached 1.96 渭moles L^鈥? d^鈥? for 50 渭M of the initial PCP concentration: one of the highest efficiencies reported. This compact anaerobic mineralization system requiring no external supply of an electron acceptor would be useful for the remediation of chlorinated aromatic compounds under anaerobic conditions.