The concentration of rural farmers' residential areas is not as high as that of cities, and the intensity of domestic sewage production is lower than that of cities. The financial resources of villages and towns are weak, and farmers' income is low. It should be encouraged to adopt diversified domestic sewage treatment technologies that are economical, simple, effective, and combined with local agricultural production as much as possible. Domestic sewage treatment equipment should achieve harmless treatment and resource utilization of sewage.

In recent years, rural domestic sewage treatment processes have varied, but they are all different combinations of treatment technologies from various units. Practical technologies for rural sewage treatment include septic tanks, sewage purification biogas digesters, ordinary aeration tanks, sequencing batch bioreactors, oxidation ditches, biological contact oxidation tanks, artificial wetlands, land treatment, and ecological ponds. Based on the functional requirements of the receiving water body, combined with the economic situation, infrastructure, complete natural environment conditions, and drainage direction of rural areas, select suitable treatment technologies for the local area.

Process of rural domestic sewage treatment：

Biological contact oxidation method, SBR, A/O, A2/O, etc.

Working principle of rural domestic sewage treatment equipment:

The removal of organic pollutants and ammonia nitrogen mainly relies on the AO biological treatment process in the equipment. The working principle is at level A. Due to the high concentration of organic matter in sewage, microorganisms are in a state of hypoxia. At this time, microorganisms are facultative microorganisms. Therefore, level A tanks not only have a certain function of removing organic matter, reducing the organic load on subsequent aerobic tanks, and reducing the concentration of organic matter, but there is still a certain amount of organic matter and high NH3-N present. In order to further oxidize and decompose organic matter, and ensure smooth nitrification under carbonization, an aerobic biological contact oxidation tank with low organic load is set up at level O. There are mainly aerobic microorganisms and autotrophic bacteria (nitrifying bacteria) in the O-level pool. Aerobic microorganisms decompose organic matter into CO2 and H2O; Autotrophic bacteria (nitrifying bacteria) use inorganic carbon produced by the decomposition of organic matter or CO2 in the air as a nutrient source to convert NH3-N in wastewater into NO-2-N and NO-3-N. The effluent from the O-grade pool is returned to the A-grade pool, providing an electron acceptor for the A-grade pool and eliminating nitrogen pollution through denitrification.