Study on the effect of temperature on the microbial community of activated sludge

In order to explore the effects of temperature on microbial community diversity on activated sludge, winter and summer activated sludge in the same sewage treatment system were selected for comparison. The experimental results show that in winter, when the activated sludge is prone to expansion and the activated sludge expands, the bacterial phyla with the largest relative abundance is Chloroflexi, while the largest phyla in the normal activated sludge is Proteobacteria, and the abundance of Actinobacteria and Bacteroidota in the other two sludges is also very different. Through the analysis of environmental factors, it was judged that under the environmental stress of low temperature and low dissolved oxygen, the proliferation of Chloroflexi and Bacteroidota in the activated sludge was determined, which inhibited the growth of Proteobacteria and Actinobacteria and triggered sludge expansion. In addition, the related microorganisms in the winter sludge have a strong metabolic capacity for carbohydrates and proteins, indicating that under long-term extreme conditions, the microbial community can form a rapid metabolic pattern for carbohydrates and proteins to maintain the optimal removal effect of activated sludge on pollutants. By reducing the organic load of sludge and increasing the concentration of dissolved oxygen in the water, it is found that the sedimentation of sludge has been improved, the efficiency of wastewater treatment has been improved, and the activated sludge system tends to be stable.