YULan,LIPeng-fei,ZHANGDa-fei,et al.Nitrite Accumulation Investigation and Control Strategies in Denitrifying Biofilter[J].China Water & Wastewater,2025,41(9):88-93.
Nitrite Accumulation Investigation and Control Strategies in Denitrifying Biofilter
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第41卷
Number:
第9期
Page:
88-93
Column:
Date of publication:
2025-05-01
- Keywords:
- nitrite; denitrifying biofilter; methanol; backwash cycle; influent load; sodium acetate
- Abstract:
- According to the NO2--N accumulation observed in the denitrifying biofilter during operation, experiments were carried out from multiple perspectives, including methanol dosing rate, backwash cycle, influent load, phosphorus concentration, and sodium acetate dosing rate, to investigate effective control strategies for mitigating NO2--N accumulation. When the methanol dosing rate was in the range of 20-40 mg/L, a higher dosing rate resulted in more severe NO2--N accumulation, with the maximum level exceeding 6 mg/L. Different backwash cycles and phosphorus concentrations had no significant impact on the denitrifying bacterial community; however, the accumulation of NO2--N remained at a relatively high level. When the influent load was decreased to 50%, the residence time for nitrogen removal could be significantly enhanced, and the effluent NO2--N remained consistently below 2 mg/L. However, the differentiated load ratio should be determined based on actual operational conditions. After substituting the carbon source with sodium acetate, the accumulation of NO2--N was alleviated, and the maximum accumulation was maintained within the range of 2-3 mg/L. This approach can serve as an effective strategy for controlling NO2--N accumulation.
Last Update:
2025-05-01