The integrated domestic sewage treatment equipment can solve the problems of difficult rural domestic sewage treatment, large land occupation, and difficult operation and maintenance. Through extensive practice, it has been proven that the treated sewage fully meets the Class A standard requirements of the "Pollutant Discharge Standards for Urban Sewage Treatment Plants" (GB18918-2002).

　　1. Introduction to the Process of Rural Sewage Treatment Equipment

　　1.1 Stable pond treatment process

　　A stable pond is composed of several naturally or artificially excavated ponds, which purify wastewater through the comprehensive action of algae, bacteria, and planktonic aquatic organisms in the pond, resulting in good effluent quality. The study on the treatment of village or community sewage by floating duckweed stabilization pond system found that the TSS removal rate can reach 80%, and the COD removal rate is greater than 75%. However, as the temperature decreases, the COD removal rate drops to 60%.

　　The high-efficiency algae stabilization pond improved on the traditional basis has more organisms than the traditional stabilization pond, and adds mixing devices to promote sewage mixing; Adjust the concentration of oxygen and carbon dioxide in the pond, as well as the water temperature and quality, in order to improve the removal rate of organic matter, nitrogen, and phosphorus. Efficient algae stabilization ponds are greatly affected by light, temperature, water depth, and flow velocity inside the pond.

　　1.2 Artificial wetland treatment process

　　The artificial wetland treatment system is a process of planting aquatic plants such as reeds, hemp, cattails, and water hyacinth on artificially laid substrates, and using the soil, plants, aquatic animals, and microorganisms composed of wetlands to jointly filter and absorb pollutants. According to plant types, there are emergent plants and phytoplankton, which can be classified into surface flow wetlands, alternative flow constructed wetlands, and vertical flow constructed wetlands based on water flow patterns.

　　The substrate, plants, and microorganisms in wetlands are the main components for purifying wastewater, while plants play a role in consuming nutrients and transporting oxygen. The nitrification capacity of plant constructed wetlands is significantly higher than that of non plant constructed wetlands.

　　1.3 Land treatment technology

　　Under manual control, sewage undergoes physical, chemical, and biological treatment through a soil plant system to achieve purification, which is a non powered treatment process. The existing processes in China include rapid infiltration treatment systems, underground infiltration treatment systems, etc. The rapid infiltration treatment system is a treatment process that subjects highly permeable soil to periodic flooding and drought alternation, allowing wastewater to undergo anaerobic and aerobic treatment. Has good nitrogen and phosphorus removal efficiency.

　　1.4 Biofilm treatment process

　　Biofilm method refers to the use of natural or synthetic materials (such as fibers) as carriers, where the biofilm on the surface provides an attachment surface for microorganisms. Microorganisms degrade substances in wastewater through secreted enzymes and catalysts, and the metabolic products are discharged from the biofilm. The main processes of biofilm method include biological corridors, biological filters, and biological contact oxidation tanks. The biofilm method has high treatment efficiency and significant purification effect on water bodies mildly polluted by organic matter and ammonia nitrogen. There are currently simple, easy to operate, and integrated biofilm processes such as membrane bioreactors (MBR) and intelligent small-scale domestic sewage reactors.