JiangYanbo,LuoHaobai,XuMingjun,et al.Optimization of Thickness in Pyrite Denitrifying Biofilter Based on Mintz Principle[J].China Water & Wastewater,2026,42(17):84-89.
Optimization of Thickness in Pyrite Denitrifying Biofilter Based on Mintz Principle
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第42卷
Number:
第17期
Page:
84-89
Column:
Date of publication:
2026-09-01
- Keywords:
- denitrifying biofilter; pyrite particle filler; filter layer thickness; work cycle; filter layer optimization
- Abstract:
- To address the difficulty in synergistically balancing the water quality cycle and pressure cycle during denitrifying biofilter operation, a pyrite denitrifying filter was constructed, and dynamic filtration experiments and model optimization were conducted using low-turbidity tailwater. The filtration performance of quartz sand and pyrite media was compared to investigate the effects of media particle size and filter layer thickness on suspended solids (SS) removal, thereby determining the optimal operating parameters. Based on pollutant transport-retardation theory, a pressure cycle model and a water quality cycle model were established separately. By solving these models simultaneously, a formula for the optimal filter layer thickness was derived and subsequently validated under operating conditions. The results indicated that the pyrite media achieved a 1.8% higher average SS removal rate than quartz sand, along with a longer pressure cycle and better operational stability. At a media particle size of 1.2-2.4 mm, a filter layer thickness depth of 180 cm, and a filtration rate of 6 m/h, the SS removal rate reached 79%. Model calculations yielded an optimal critical filter layer thickness of 184 cm, corresponding to an operating cycle of 26.0 h. At this point, the water quality cycle and pressure cycle simultaneously reached their operational limits, indicating that the filter was operating under optimal conditions. When the actual filter layer thickness falled below this critical value, the pressure cycle exceeded the water quality cycle; conversely, when it exceeded the critical value, the water quality cycle exceeded the pressure cycle. Both cycles exhibited a linear relationship with filter layer thickness.
Last Update:
2026-09-01