Research progress on integrated treatment technologies of rural domestic sewage

Rural domestic sewage in China has the characteristics of large amount and dispersion, so it is difficult to achieve centralized treatment. Therefore, it is very important to select rural domestic sewage treatment technologies and equipment with high treatment efficiency, good economy, strong practicability, and easy operation, maintenance and management. The processes of integrated rural domestic sewage treatment technologies were reviewed, and the applicable range, advantages and disadvantages of integrated activated sludge derived process, biofilm treatment process, membrane bioreactor (MBR) process and their combination and integration process were illustrated. The appropriate decentralized sewage treatment technology mode was analyzed, namely small integration device processing combined with centralized collection treatment. Based on the small integrated sewage treatment equipment with a treatment capacity of 5 t/d, and combined with the discharge characteristics of rural domestic sewage, the pollutant removal performance and technical and economic indexes of each treatment process were compared and analyzed. It was proposed that the integrated biological contact oxidation technology, the improved biofilm and activated sludge mixed technology and the addition of anoxic precipitation section at the end of the anaerobic-anoxic-aerobic (AAO) process were the development trends of the integrated treatment technologies of rural domestic sewage in China.