Engineering Design And Running Effect Analysis Of Rural Sewage Treatment By Constructed Wetland In Low-temperature Area

Our country is a populous and agricultural country. According to the fifth census,China’s rural population has reach to more than800million. Due to the shortage offunds and weak consciousness of the sewage treatment, most villages have nodrainage channels and sewage treatment system. Surface and underground water havebeen polluted, even the the environmental and people’s healthy are effect because ofthe sewage. It will result in a vicious cycle of water environment in countryside andrestrict the healthy development of rural economy.At present, the commonly used rural sewage treatment technology in China arewetland treatment system, land treatment system, stabilization pond treatment system,anaerobic pool, etc., Considering the northern rural areas is relatively backward ineconomic condition and It’s low-temperature in winter, after comprehensive analysisof various technical and engineering running instance, the wetland treatment system isthe suitable technology for the northern rural sewage.Constructed wetland has different forms, the running effect and operatingindicators are also different. By comparing the constructed wetland runningparameters and treatment effect which has been put into used in the northern region,we finally determine the wetland engineering design scheme is: contact oxidationditch+subsurface flow wetland+surface flow wetland.After the engineering is put into used, monitoring the in-water and out-water,besides the wetland works as a storage facility in the winter without water flow out,the wetland processing efficiency of COD is about80%~85%, the efficiency of TNis about90%, the efficiency of NH4+-N is about90%~95%, the efficiency of TP isabout75%~85%, the out-water quality can reach the<town sewage treatment plantpollutant discharge standard>(GB18918-2002) leve one standard.