Pilot Study on Integrated Reactor for Treatment of Low-concentration Rural Domestic Sewage

The pilot study on the integrated reactor combining anaerobic biofilter and aerobic contact oxidation process for treatment of low-concentration rural domestic sewage was performed.Influences of hydraulic retention time(HRT),dissolved oxygen(DO) on the treatment efficiency as well as the anti -shock loading performance of the reactor were investigated.Taking the removal effect of nitrogen and phosphorus and energy consumption into account,the optimal operation conditions are determined as follows; HRT is 7.5 h,and DO is 3 mg/L.Under these conditions,the removal rates of COD,NH_4~+-N, TN,TP are 69.39%,84.01%,71.01%and 20.90%respectively.The effluent quality meets the second class criteria specified in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918 -2002).The integrated reactor has good application prospect in decentralized treatment of rural domestic sewage due to its strong anti-shock loading capacity,less excess sludge production and operation cost of 0.22 yuan/m~3.