Optimized Strategies In Utilizing Compound Microorganism Preparation At Low Carbon Source CASS Technology Oriented Sewage Plants To Neutralize Nitrogen And Phosphorous

In view of the increasingly severe sewage treatment problem,this paper aims to add microbial agents composed of more than 20 kinds of bacteria as the main means,and study the enhanced sewage treatment effect after the addition of bacteria as well as the economic feasible vaccination scheme.In the case of low carbon source and high load this paper aims to propose a viable bioaugmentation technical scheme.The main research contents and achievements are as follows:(1)Taking a sewage plant in Chengdu as example,there are always problems such as drainage rich in nitrogen,phosphorus and other pollutants leaks into the sewage plant area often due to improper management and wrong leakages.Coupled with low carbon source in southern city,it usually results in high load to the sewage plant and poor water quality.(2)Adding the compound bacteria into the domestic sewage,anaerobic and aerobic processing were made during this experiment.During the denitrification process nitrification reaction removes ammonia nitrogen and denitrification reaction removes nitrite,the removal rate increased from 69.3%To 75.7%comparing to the control group,77.7%to 82.0%,and the removal rate for phosphorus removal increased from 60.0%to 71.3%.(3)The orthogonal test was carried out by taking the sludge concentration,the aeration ratio,the sludge reflux and the added compound microbiological agents as the control factors taking the three levels,simulating the CASS process.The results were analyzed by the difference and variance and the best combination of conditions is sludge concentration 2000mg/L,aeration ratio of 50%,bacteria content of 1/1000,sludge reflux ratio of 20%.In optimization conditions,TP,TN removal rate increased such as the average TN removal rate increased from 68.5%to 71.8%,and the average removal rate of TP increased from 61.5%to 69.7%comparing to the stable period.(4)Vaccination scheme contains the initial addition of the ratio of 1/1000 of the funguscontent,the same amount of bacteria after a week,and then addition of compound preparation by 1/10000 ratio per month.TN,TP removal effect reaches 72%and 69%,and the monthly cost is about 6,000 yuan after stabilization for the sewage plant with effective CASS pool volume of 15900m3,Saving cost as high as more than 50000.This study provides a practical theoretical research and implementation plan for the improvement of effluent quality in the face of the increasingly severe water treatment environment problem.