title: Biodegradation of perchloroethylene and chlorophenol co-contamination and toxic effect on activated sludge performance.
abstract: This study investigated the effects of PCE and 2-CP co-contamination on growth of microbial community in terms of enzymatic activity and microbial diversity in activated sludge. Results showed that the activities of three key enzymes (dehydrogenase, phosphatase and urease) decreased significantly when PCE (in the range of 5-150 mg/L) was mixed with 2-CP (in the range of 25-150 mg/L). Especially, activity of dehydrogenase decreased by more than 93% as the concentration of PCE and 2-CP both reached 150 mg/L. PCR-DGGE revealed that short-term exposure with PCE and 2-CP did not lead to shift in the microbial community structure, while clone library demonstrated a significant change in the microbial diversity after long-term exposure. As the population of Alphaproteobacteria and Gamaproteobacteria decreased, with Actinobacteria eventually disappeared, species including Firmicutes, Bacteroidetes and Synergistetes became dominating groups. This study demonstrated that co-contamination with PCE and 2-CP affected the performance of activated sludge in a significant way.
authors.affiliation: State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Shen
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Wang
authors.forename: Kuang-Fei
authors.initials: KF
authors.lastname: Lin
authors.forename: Yong-Di
authors.initials: YD
authors.lastname: Liu
authors.forename: Shu-Guang
authors.initials: SG
authors.lastname: Lu
authors.forename: Ji-Dong
authors.initials: JD
authors.lastname: Gu
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Lu
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Du
mesh_terms: D001673:Biodegradation, Environmental; D002733:Chlorophenols / Q000378:metabolism* / Q000633:toxicity; D003001:Cloning, Molecular; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000378:metabolism; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000737:chemistry; D012722:Sewage / Q000737:chemistry*; D013750:Tetrachloroethylene / Q000378:metabolism* / Q000633:toxicity
chemical_list: D002733:Chlorophenols; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D010088:Oxidoreductases; D010744:Phosphoric Monoester Hydrolases; D013750:Tetrachloroethylene