Autotrophic Denitrification Characteristics of Urban Wastewater Treatment Plant Effluent Driven by Sodium Sulfite

Sulfated denitrification process has attracted more and more attention because it does not depend. on the addition of organic matter. Nowadays, the tailwater from urban wastewater treatment plant has high nitrogen concentration. In this case, we propose a sodium thiosulphate siderite autotrophic denitrifying (STSAD) biofilter for the removal of nitrogen from the tailwater of the urban wastewater treatment plant. Under the optimal conditions, the NO3--N removal rate was 100%, TN removal rate was above 95%. Many microorganisms were enriched on the surface of the ceramsite and siderite filler in the reactor, and the main denitrification microorganisms in the filter were Thiobacillus and Ferritrophicum. The process has certain technical and economic feasibility for denitrification in the tailwater of urban wastewater treatment plant, the cost is only 0.042 CNY/t(water), and the effluent TN and COD meet the requirements of water quality standards, so it is a suitable method.