JIANG Fu-hai.Application Practice of Autotrophic(Heterotrophic) Denitrification in a WWTP with Low C/N Ratio Influent[J].China Water & Wastewater,2021,37(12 12):124-131.
Application Practice of Autotrophic(Heterotrophic) Denitrification in a WWTP with Low C/N Ratio Influent
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第37卷
Number:
12 12
Page:
124-131
Column:
Date of publication:
2021-06-17
- Keywords:
- low C/N ratio; heterotrophic denitrification; sulfur-based autotrophic denitrification; autotrophic denitrification filter; enhanced nitrogen and carbon removal
- Abstract:
- It’s recommended for the wastewater treatment plant (WWTP) with low C/N ratio influent to use cascade process of heterotrophic denitrification and autotrophic denitrification filter, so as to achieve high discharge standard. Nitrogen-removal efficiency of autotrophic denitrification filter is easily affected by influent temperature, DO, and NO3--N load. When influent temperature is within 25 to 30 ℃, influent NO3--N concentration is less than 15 mg/L, and HRT of filter is above 20 minutes, the filter’s denitrification-load could be 0.56 kgTN/(m3·d) and TN removal efficiency reached 60%, meanwhile the ratio of active media consumption to TN reduction is about 3.9. When the influent DO exceeded 2 mg/L, the sulfurbased filter media would be partly oxidized and consumed inefficiently. Thus, Na2S2O3 could be added as an auxiliary electron donor. Activated sulfur-based autotrophic filter media with particularly size of 2.0 to 3.5 mm, supplemented with double layer composite quartz-sand, was selected to ensure the collaborative reduction of TN and SS pollutants, and to attain obvious benefits of chemical saving by using the autotrophic filter media. Long term attention should be paid to the nitrogen removal efficiency at low water temperature and whether the by-products such as SO2-4, H2S and NO2--N were accumulated in the autotrophic denitrification filter. The dominant microbial colonies of autotrophic filter media were Thiobacillus and Sulfurimonas, and the abundance of both was more than 50%.
Last Update:
2021-06-17