Due to the strong dispersion in the treatment process of rural sewage, it is very difficult to treat. With the emergence of integrated sewage treatment equipment, the problem of rural sewage in sewage treatment has been completely solved.
The supporting facilities in rural areas are outdated, and some households breed livestock and poultry, and the feces of animals are excreted everywhere. Various washing sewage, kitchen waste water and human and animal excrement are the main sources of water pollution in rural areas.
The composition of rural sewage
The composition of rural sewage is similar to that of urban domestic sewage. The nitrogen and phosphorus concentration in sewage is high and contains a lot of nutrients, bacteria, viruses, etc.; due to livestock manure, it also contains pathogenic bacteria, viruses and parasite eggs; the main characteristics of new rural sewage There are low treatment rates, intermittent discharge, small and dispersed discharge.
Hazards of Direct Discharge of Sewage
Because the construction of sewage treatment systems in rural areas is generally relatively backward, most of the sewage directly enters rivers, lakes and reservoirs, causing serious pollution to water bodies. Livestock feces contain parasite eggs and pathogenic bacteria, which infiltrate into groundwater after being washed by rainwater, causing pollution to groundwater. Since most of the water in rural areas is well water (groundwater), it will pose a threat to people's health. At present, most of the villages do not have drainage channels and sewage treatment systems, and the random discharge of sewage can increase the content of nitrogen, sulfur and phosphorus in the water body, cause eutrophication of the water body, and seriously damage the water body environment.
Methods of collecting sewage in rural areas
In view of the dispersive characteristics of rural sewage, one can use one integrated sewage treatment equipment for each household or adopt a unified sewage discharge pipe network to collect and discharge it to the sewage collection area, such as: septic tanks, regulators, etc. pool.
Rural sewage treatment process
The organic content of rural sewage is high, and the COD of sewage such as urban domestic sewage is higher than that of urban domestic sewage. The sewage contains a large amount of organic matter, nutrients and other components. The B ratio of the sewage is greater than or equal to 0.45 (BOD5/CODcr), and the biodegradability is good. Most of the sewage adopts the biological treatment method (WSZ-AO). Because some areas belong to water source protection areas, the requirements for sewage discharge standards are more stringent. For these areas, the conventional WSZ-AO biological treatment method is difficult to meet the standard due to the influence of ambient temperature, and high-efficiency infiltration field sewage treatment technology is required. The load underground infiltration technology is very suitable for the decentralized sewage treatment in beautiful and new rural areas. The technology is not affected by temperature and has a stable treatment effect. It can effectively remove Cod, Bod, SS, ammonia nitrogen, phosphorus and other organic substances in sewage. In addition to underground infiltration, this technology also adds underground wetland function, which can further improve the pollutant load capacity of the system, and we are in engineering applications. The sewage load does not exceed 50% of the theoretical load capacity, so the system can never be blocked. The quality of the effluent can reach the Class A discharge standard of urban sewage treatment plant (GB18918-2002), and the operation is stable.