Research of rural domestic sewage treatment processes in Ningbo

Through comparing national, provincial and municipal standards in rural domestic sewage treatment, appropriate standards and indexes are chosen to implement rural sewage treatment in Ningbo. Among some commonly used rural sewage treatment processes under such climate as Ningbo, there are four most often used processes in the first phase of Ningbo from year 2009 to 2012. In order to assess the effluent treatment effects, four typical sewage quality indexes, which are COD_Cr, SS, TN and BOD₅, are chosen to assess effluent qualities in four typical processes. The investigation results show that every process of the four typical processes has its advantage in rural sewage treating, and there is no process can remove all the sewage pollutants to the most simultaneously. The operation results of different processes are compared in details in this paper. Through the research, it can help to eliminate inappropriate processes and explore some suitable processes for rural domestic treatment. As a result of the research of rural sewage treatment processes in Ningbo, two kinds of typical composite processes are respectively demonstrated in different occasions in water-source-protecting areas and non-water-source-protecting areas. (paper)