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.
Bibliographical noteFunding Information:
This research was financially supported by the National Natural Science Foundation of China ( 41003031 , 41273109 ), the Shanghai Rising-Star Program ( 12QA1400800 ), the Specialized Research Fund for the Doctoral Program of Higher Education ( 20110074130002 ), the National Environmental Protection Public Welfare Science and Technology Research Program of China ( 200909089 , 2010467032 , 201109013 ), the Key Science Foundation of Shanghai Environmental Protection Bureau (Huhuanke2012-07), the Fundamental Research Funds for the Central Universities (WB1014004,WB1314002), the National Science Foundation for Postdoctoral Scientists of China ( 2012M510811 ). We also would like to thank the anonymous referees for their helpful comments on this paper.
- Activated sludge
- Enzyme activity
- Microbial community diversity