Methods for Classification of Domestic Sewage Treatment Systems in Rural Areas (I) Classification of Methods for Domestic Sewage Treatment Systems in Rural Areas (I) At present, sewage treatment systems are mainly based on the requirements of the sewage treatment level using one or several treatment technologies or Process joint treatment of sewage. In accordance with the applicable conditions of sewage treatment technology, domestic sewage treatment systems in rural areas can be divided into centralized treatment and distributed treatment of two categories. (1) centralized processing system. The centralized treatment system mainly refers to (small-scale) sewage treatment plants, constructed wetland systems or land treatment systems, etc., which aim to reduce the pollutants in the sewage through a series of physical, chemical and biological measures so as to achieve the purpose of sewage purification and resource utilization . (2) decentralized processing system. Dispersing system is a highly concentrated miniaturized wastewater treatment plant. It uses a combination of physical, chemical or biological processes to integrate various processing technologies in a small space. With the development of various techniques and technologies, more and more types and models of distributed processing systems have been developed. Water reuse by treatment methods: 1. Physical treatment: membrane filtration method, suitable for large changes in water quality. This process is characterized by: a compact, easy to operate, and less affected by load changes. Membrane filtration is under the action of external force, the separated solution flows along the surface of the membrane at a certain flow rate. The solvent and low molecular weight substances in the solution, the inorganic ions pass through the membrane from the high pressure side to the low pressure side and are discharged as the filtrate ; While the solution of polymer materials, colloidal particles and microorganisms were intercepted by the ultrafiltration membrane, the solution is concentrated and discharged in concentrated form. 2. Physical and Chemical Law: For changes in the quality of sewage water larger. The commonly used methods are: sand filtration, activated carbon adsorption, flotation, coagulation sedimentation (PAC, polyacrylamide) and so on. This process is characterized by: hollow fiber ultrafiltration for processing, advanced technology, compact structure, small footprint, the system intermittent operation, simple management. 3. Biological treatment method for high organic content of sewage. The general method of activated sludge, contact oxidation, biological rotary disc and other biological methods. Or alone, or a combination of several biological treatment methods, such as contact oxidation + biological filter; biological filter + activated carbon adsorption; This process has the ability to adapt to changes in hydraulic load, resulting in less sludge, easy maintenance and so on. For more information, please pay attention to http://www.gyzhenyu.com