IntroductionBy the end of 2020, China had completed the comprehensive improvement of the rural environment in 150,000 administrative villages. However, there are still problems such as low rural domestic sewage treatment rate and unbalanced regional development. The purpose of this paper is to analyze the current situation of rural domestic sewage collection and treatment, drainage system, collection and treatment mode, treatment technology, etc., and compare the commonly used treatment technologies, so as to provide guidance for the selection of rural domestic sewage treatment technology. 1. Status quo of collection and processing1.Yield processing rateAccording to the "Statistical Yearbook of China's Urban and Rural Construction" (2019), China has about 1870,000 towns, 0950,000 townships, 462 special areas, 5150,000 administrative villages, 251There are 30,000 natural villages with a registered population of 96.7 billion. However, the sewage treatment rate in rural areas is significantly lower than that in cities, and the overall treatment rate is much lower than that in urban areas (96).8%。
Table 1 Current status of rural domestic sewage collection and treatment2.Water qualityRural domestic sewage mainly comes from manure, washing, showering, etc. in daily life, which contains high concentrations of organic pollutants and nutrients such as nitrogen and phosphorus. These water quality indicators fluctuate greatly, and there are obvious differences in pollutant concentrations between the north and the south. 
Table 2 Water quality of rural domestic sewage3.The amount of waterThe amount of sewage drainage in rural areas fluctuates greatly, which is related to water consumption and drainage coefficient. The per capita domestic water consumption in rural areas of the country is 912l (man-days), but the degree of perfection of the drainage system facilities varies, resulting in seasonal and daily fluctuations in the amount of drainage. 2. Drainage systemThe rural drainage system is divided into a confluence system, an interception system, a diversion system, etc., and each system has its advantages, disadvantages and scope of application. Some of the existing drainage systems needed to be retrofitted to meet the requirements of modern diversion systems. 
Table 3 Rural drainage system3. Collection and processing modeThe collection and processing mode mainly includes household collection and processing, village centralized collection and processing, and integration into the urban pipe network. Each mode has its own applicable treatment methods and advantages. 
Table 4 Rural sewage collection and treatment modeFourth, the treatment process technologyRural domestic sewage treatment technology includes pretreatment, biochemical treatment, advanced treatment, etc., involving activated sludge method, biofilm method, ecological treatment method, etc. The choice of these technologies depends on factors such as treatment scale, emission standards, cost, etc. 
Table 5 Advantages and disadvantages of common representative process technologies for rural sewage treatment In terms of pretreatment, they mainly involve physical interception, regulation, sedimentation and other measures. The activated sludge treatment method has a high treatment load and can effectively remove organic matter, nitrogen and phosphorus, but the operation and maintenance management is relatively complex and the cost is high. The biofilm method has good treatment effect, convenient operation and maintenance management, and is suitable for various sewage treatment facilities. The ecological treatment method has low energy consumption and is ecologically sustainable, but the treatment load is low and requires a large amount of land. In addition, there are emerging technologies, such as source separation, innovative technologies in the field of microbial treatment of wastewater, etc. These new technologies show many advantages in treating wastewater, but require stricter control of water quality and environmental parameters. Finally, according to the actual situation, many rural wastewater treatment adopts a combination of process technology, combining different processes to meet the effluent water quality standard. Factors such as treatment scale, emission standards, cost, and O&M management should be taken into account when selecting the right technology. ConclusionThe selection of rural sewage treatment technology should take into account multiple factors such as local discharge standards, economic conditions, and operation and maintenance management. The future direction of technology development should focus on the goals of low cost, easy maintenance, high water quality, and resource utilization. China's rural sewage treatment industry has entered a stage of comprehensive development, and the formulation of local discharge standards has also been more adapted to local conditions, and rural sewage treatment has been gradually improved.