Abstract:

In recent years, there is a trend of low C/N ratio in municipal domestic wastewater, which   results in serious problems of denitrification of wastewater. This paper presents the experimental study on ABR & Biocontact Oxidation Process to treat low C/N ratio domestic wastewater, determines the experimental operating parameters, and the result shows that in the range from 2 to 7 of the COD/N ratio of influent, when HRT=10 h, R=2.5, T=30 ℃, the removal rate of TN shows the satisfactory performance. The average denitrification rate decreases rapidly as the COD/N ratio of influent reduce, which is due to the lack of carbon source. Under the satisfactory operating conditions, when the COD/N ratio of influent is 6-7, the average denitrification rate reaches more than 80%, and the concentration of TN in effluent is lower than 15 mg/L, which meets the first A standard of Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant.

Key words: ABR, biocontact oxidation, low C/N ratio, nitrogen removal