Study On Separation Treatment Of Night Soil And Grewater With Bio-ecological Process Of Small-sized And Decentralized Domestic Wastewater

In this paper,it is proposed that the night soil is treated with an anaerobic baffled reactor and the effluent mixed with gray water into the anoxic reactor.The combined bio-ecological process of "anaerobic-anoxic-aerobic-constructed wetland" was proposed because the polluant concentration of the black water is high and the water yield is low.The waterwheel driving rotating biological disks were used in aerobic unit to ensure adequate oxygenation in the section of energy-saving conditions.Combined with anoxic unit,the nitrogen-containing pollutants could be removed effectively.The constructed wetland was set to further denitrificated and ensure the removal of phosphorus.The main conclusions are as followed:(1)The COD?TN and ammonia nitrogen removal rate of anaerobic baffled reactor(ABR)rised with HRT increasing under the temperature of 35±1? When the HRT was 72h,the COD removal rate reached 90%.The TN removal rate reached 32%.The ammonia nitrogen removal rate reached 33.45%.72h was suggested as the appropriate HRT for ABR.The reactor compartment number was suggested 5.(2)Biogas production of ABR increased with the increase of volume load.Across with the study,the variation of pH was steady and constant.The VFA concentration is less than 480mg/L,no acidification phenomenon happens.(3)The COD removal rate and denitrification effect of anoxic reactor-aerobic waterwheel driving rotating biological disks rised with nitrification liquid reflux ratio increasing.In summer and autumn,the COD removal rate was 82.12%and the TN removal rate was 51.23%when the nitrification liquid reflux ratio was 200%.In winter and spring,the COD removal rate was 68.09%and the TN removal rate was 29.96%when the nitrification liquid reflux ratio was 200%.(4)The C/N ratio of anoxic reactor-aerobic waterwheel driving rotating biological disks was important factor that affecting the effect of denitrification.The best denitrification rate was 9 in summer/autumn and 6.1 in winter/spring respectively.(5)The denitrification effect of anoxic reactor-aerobic waterwheel driving rotating biological disks was affected by HRT.It was suggested that the HRT of anoxic reactor and aerobic waterwheel driving rotating biological disks was 4.5h and 1.9h respectively in summer/autumn,and 6h and 2h respectively in winter/spring.(6)Combined with the ecological unit,with the COD,TN,ammonia nitrogen and TP concentration of effluent were 9.16?36.69mg/L?2.95?12.68mg/L?0.42?3.48mg/L and 0.26?0.8mg/L respectively.The quality of the effluent reached CGB18918-2002 A level of the national discharge standard of pollutants for municipal wastewater treatment plant.