Study of the characteristics of pollutants in rural domestic sewage and the optimal sewage treatment process: a Chengdu Plain case study

Domestic sewage is an important source of surface water pollution in the rural areas of developing countries, especially in the rural areas of China. In recent years, with the strategy of rural revitalization, China has paid increasing attention to the treatment of rural domestic sewage. The characteristics of domestic sewage discharged from rural areas in each region have not been sufficiently studied, and the selection of treatment processes for wastewater treatment plants in different areas needs further research. Therefore, 16 villages in the Chengdu Plain were selected for the study, and 7 indicators were analyzed and evaluated, including pH, BOD5, COD, NH3-N, TP, SS, and TN, in the water samples at the inlet and outlet of the wastewater treatment plant. The preferred process for removing each pollutant was obtained by studying the effects of the treatment process, season, and hydraulic retention time on the removal efficiency of each pollutant. The research results provide new ideas for the control and treatment engineering of rural surface source pollution in Southwest China, as well as valuable references for the planning and process selection of rural domestic sewage treatment.