Study On Effect And Microbial Community Of Sewage Treatment Plant By Microbial Agents

With the improvement of the sewage treatment capacity and the increasing output of the sludge, the existing treatment methods all have some defects. Situ reduction technology which adds microorganism agent provides a new way to solve the sludge problem. But now more studies f ocus on the reduction effect, only a few of which focus on the treatment effect of the microbial agents and reduction mechanism. Therefore in this paper, we focus on the sewage treatment effect in different dosing methods and in different dosing quantities by SBR and A2/O test. We discussed the mechanism of sludge reduction of microbial agents by analyzing biochemical factors and different microbial species.After studying the application parameter of different adding methods, we found under the continuous dosing and intermittent dosing conditions, the removal rate of CODcr of the agent group and the comparing group was higher than 90%, the removal rate of NH3-N was higher than 95%.Dosing agent had nothing to do with the removal of CODcr, NH3-N and other pollutants, and it leds to a drop of the out water TP. We found the CODcr removal rate of agent group and comparing group was higher than 90%, the NH3-N removal rate was higher than 96% through studying the dosing quantity optimizing methods.Dosing agent had nothing to do with the removal of CODcr, NH3-N and other pollutants, the out water TP fell.During the research in the reduction mechanism, we find adding the microbial agent strengthens the enzyme secretion. The bacterium dehydrogenase, amylase and protease content in agent group respectively increase by 17.1%, 28.4%, 20% as the none dosing group. The decrement rate shows a certain positive correlation with content of dehydrogenase,amylase and protease. Overall, the effect on sludge reduction is protease>amylase>dehydrogenase. The improving of the endogenous respiration rate tells it improves the metabolic activity by dosing agents and it helps the sludge reduce.Polysaccharide and protein content of EPS,which tells the microbial agents strengthen the degradation rate of organic matter.By analyzing OTU in SBR and A2/O methods, we find the bacterium agent system gets more complex and composition of species is much higher by dosing agents. By analyzing the species, we find the proteobacteria(deformation bacteria) and the Bacteroidetes are the main microbial populations, each consists 50% and 30% of the total effectre.