SRA

In view of the low carbon to nitrogen ratio of wastewater treatment plant tailwater and the need for external carbon source for deep denitrification, which leads to higher operating costs, this study combines the high NH4+-N and COD concentrations in secondary influent and the high NO3-N and low COD concentrations in secondary effluent of the wastewater treatment plant and proposes to mix some of the secondary influent and secondary effluent into the biofiltration tank, and to realize the part of the short-range denitrification coupled with anaerobic ammonia oxidation reaction in the biofiltration tank. It is proposed to mix part of the secondary influent with the secondary effluent into the biofilter, and then realize part of the short-course denitrification coupled with anaerobic ammonia oxidation in the biofilter to provide the carbon source required for the short-course denitrification reaction and NH4+-N required for the anaerobic ammonia oxidation reaction in the secondary influent, so as to realize the purpose of energy saving and consumption reduction. In addition, by adding Mn(II) and inoculating manganese oxidizing bacteria, biomanganese oxides are generated to oxidize some of the difficult-to-degrade organic matter in the secondary effluent water, which can be formed into readily degradable organic matter to be used as a carbon source by denitrifying bacteria, and optimize the process operating parameters, which can further improve the effluent water quality under the premise of ensuring that the effluent water quality meets the standards.