A2/0 Process|Water Treatment Equipment
分类:Common Problem
时间:2020-12-07 09:31:24
What is a2/0 process?
A2/0 process is the abbreviation of Anaerobic-Anoxic-0xic, which is the abbreviation of anaerobic-anoxia-aerobic biological nitrogen and phosphorus removal process. A20 biological nitrogen and phosphorus removal process is a combination of traditional activated sludge process, biological nitrification and denitrification process and biological phosphorus removal process.
The processing efficiency of this process can generally reach: BOD5 and SS are 90%-95%, total nitrogen is more than 70%, and phosphorus is about 90%. It is generally suitable for large and medium-sized urban sewage plants that require nitrogen and phosphorus removal. However, the infrastructure and operating costs of the A2/0 process are higher than the ordinary activated sludge method, and the operation and management requirements are high. Therefore, for the current national conditions in my country, when the treated sewage is discharged into a closed water body or a slow-flowing water body, it will cause eutrophication. This process is only used when it affects the water supply source.
In the activated sludge of the A20 biological nitrogen and phosphorus removal system, the bacterial flora is mainly composed of nitrifying bacteria, denitrifying bacteria, and phosphorus accumulating bacteria. In the aerobic section, nitrifying bacteria convert the ammonia nitrogen and organic nitrogen in the inflow into nitrate through biological nitrification; in the anoxic section, denitrifying bacteria transfer the nitrate brought in by the internal reflux through biological denitrification In the anaerobic section, phosphorus accumulating bacteria release phosphorus and absorb easily degradable organic matter such as low-grade fatty acids; while in the aerobic section, phosphorus accumulating bacteria are excessive Phosphorus is absorbed and removed through the discharge of excess sludge.