Water sources that need to be treated before being discharged into the environment: Waste water from urban areas and concentrated residential areas; wastewater from industrial plants, food processing plants, animal husbandry farms, aquaculture / aquaculture; Wastewater from industrial zones... This is the type of wastewater with high BOD/COD concentration, as well as total nitrogen or phosphorus, etc. that need to be treated with biological treatment system.
The basis of biological treatment is based on the ability of microorganisms to dissolve organic and insoluble organic bonds - using them as food sources.
There are main biological treatment processes often applied in wastewater treatment technology:
The process of decomposing organic matter by microorganisms is called biochemical oxidation. To carry out this process, dissolved organic matter, colloids and small dispersants in wastewater need to move into the microbial cell in three main stages as follows:
The rate of biochemical oxidation depends on the structure, the concentration of organic matter, the content of impurities and the stability of the wastewater flow into the treatment system. Under certain treatment conditions, the main factors affecting the biochemical reaction rate are hydrodynamic regimes, oxygen content in wastewater, temperature, pH, nutrition and trace elements, etc.