Analysis Of The Influence Of Trace Copper Ion On Microbial Community Structure In SBR

The microbial biodiversity and population structure will be changed when trace copper ion exists in the sewage, and then operating conditions and effect of the biological waste treatment systems will be influenced. This research uses sequencing batch reactor(SBR) as test object to analyze the influence of trace copper ion of four different concentrations on biological community structure. In this issue, the changes of biological diversity index and population structure of Total bacteria, Nitrifying bacteria(Nitrobacteria, Nitrosobacteria) and Denitrification bacteria are researched.It is used technique of PCR-DGGE to analyze microbial community structure and succession of total bacteria in the cultivation and domestication process of different concentrations of trace copper ion(1mg/L, 2mg/L, 3.5mg/L). During the domestication process, the biological diversity indices of all Total bacteria always decrease after the first increase, which ultimately are lower than witout domestication. And the higher the concentration of copper ions is, the sooner biodiversity index is lower than without domestication and the smaller biodiversity index is at the end of domestication. Population structure is greatly impacted by the copper ions in the domestication process. The higher the copper ion concentration is in the sewage, the sooner population structure adjustment comes and the more obvious the change is.Biological community structure of Nitrobacteria, Nitrosobacteria and Denitrification bacteria are analyzed before and after the domestication of different concentrations of trace copper(1mg/L, 2mg/L, 3.5mg/L, 5mg/L) in the sewage treatment system. The results show that major changes of the community structure have taken place and the concentration of dosing copper ion is positively correlated with the magnitude of changes. Three kinds of undomesticated bacteria are relatively rich in all treatment systems. The diversity index of Nitrosobacteria domesticated by copper ion whose concentration is 1mg/L increases slightly, which indicates a pretty low concentration of copper ions can promote the growth of bacteria. In other conditions, the presence of copper ion can reduce their diversity indices, in which the Denitrification bacteria is impacted most significantly.