working principle:

Introduction to Anaerobic Biofilter
1. The working principle of anaerobic biofilter
1) Filtering function: The packing material intercepts and filters large particles and suspended solids in the incoming water;
2) Hydrolysis: Anaerobic microorganisms can hydrolyze insoluble substances of large molecules into soluble substances of small molecules;
3) Absorption function: Anaerobic microorganisms adsorb and absorb organic pollutants in water, some of which are used for their own growth and reproduction, and some are sealed in U-shaped water in the form of biogas;
4) Denitrification effect: The effluent from the contact oxidation bed is refluxed to the anaerobic filter, and denitrifying bacteria in the anaerobic microorganisms can utilize the nitrate nitrogen in the reflux water and convert it into nitrogen gas to remove nitrogen substances from the wastewater.
After being treated by anaerobic filters, rural sewage reduces the concentration of suspended solids, organic pollutants, and nitrogen, as well as the subsequent load on the contact oxidation bed.

2. The principle of contact oxidation bed
1) Adsorption effect: During the growth and reproduction process of aerobic microorganisms on fillers, they form biofilms with larger surface area and higher concentration, which can adsorb a large amount of organic pollutants in water and reduce the concentration of pollutants;
2) Ingestion and decomposition: With continuous air flow into the reactor, aerobic microorganisms can absorb adsorbed organic pollutants as nutrients and metabolize them. Some of them are used for their own growth and reproduction, while others are converted into carbon dioxide and water.
The contact oxidation bed further reduces the concentration of organic pollutants in rural sewage, and the removal rate of CODcr and BOD5 in the effluent reaches over 80%, which can meet the second level standard for sewage discharge.
3. Working principle of sedimentation tank
1) By utilizing gravity, suspended sludge with a specific gravity greater than that of water in the effluent from the contact oxidation bed can sink to the bottom of the tank, thereby removing it from the water and ensuring good effluent quality;
2) The sludge settles to the bottom and automatically returns to the contact oxidation bed to maintain the sludge concentration in the contact oxidation bed.
4. The disinfection pool uses solid chlorine to disinfect the effluent, which can effectively kill pathogenic microorganisms such as bacteria, Escherichia coli, and viruses in the water. The treated water is clear, transparent, odorless, and the bacterial and Escherichia coli counts meet the sewage discharge standards.