XUHongbin,GAOZhao,YAOSongyuan,et al.Advanced Nitrogen Removal in Self-cleaning Biological Filter Based on Activated Coke Media[J].China Water & Wastewater,2026,42(9):87-93.
Advanced Nitrogen Removal in Self-cleaning Biological Filter Based on Activated Coke Media
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第42卷
Number:
第9期
Page:
87-93
Column:
Date of publication:
2026-05-01
- Keywords:
- activated coke; self-cleaning biological filter; advanced nitrogen removal; nitrogen transformation patterns along the filter depth
- Abstract:
- To investigate the effects of different operating parameters on the advanced nitrogen removal performance of a self-cleaning biological filter, an activated coke-based self-cleaning biological filter (AC-DNBF) was constructed. By adjusting the filtration velocity and carbon-to-nitrogen ratio (C/N), the microbial community composition was analyzed, the efficiency of the AC-DNBF for advanced nitrogen removal from the effluent of a municipal wastewater treatment plant was evaluated, and the transformation patterns of nitrogen along the filter depth were studied. The results showed that at a filtration velocity of 4.5 cm/h and a C/N ratio of 3, the AC-DNBF achieved the highest average removal rates for NH4+-N, NO3--N, and TN, reaching 46.36%, 96.30%, and 79.69%, respectively. Under these conditions, the average effluent concentrations of NO3--N, TN, and NH4+-N were 0.35 mg/L, 2.96 mg/L, and 2.44 mg/L, respectively. Analysis of the nitrogen transformation patterns along the filter depth revealed that the rate of decrease in NH4+-N concentration showed no significant correlation with filter layer height. The AC-DNBF exhibited high efficiency in NO3--N removal, with concentration descent rates at different filter depths (2#, 3#, 4#, and 5#) of 55.89%, 20.72%, 10.82%, and 5.50%, respectively. Notably, the bottom layer of activated coke in the AC-DNBF demonstrated the best NO3--N removal performance. Accumulation of NO2--N was observed along the filter depth, which could be attributed to incomplete nitrification due to low dissolved oxygen concentrations at this stage. At the phylum level, the dominant bacterial phyla were Proteobacteria and Bacteroidetes, both of which were common autotrophic denitrifying microorganisms in denitrification processes.
Last Update:
2026-05-01