WANG Ya-jun,GENG Chong-chong,XU Yan,et al.Effect of Different Enhanced Methods on Efficiency of Denitrification and Phosphorus Removal in Bioretention Cell[J].China Water & Wastewater,2020,36(19 19):77-82.
Effect of Different Enhanced Methods on Efficiency of Denitrification and Phosphorus Removal in Bioretention Cell
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第36卷
Number:
19 19
Page:
77-82
Column:
Date of publication:
2020-10-01
- Keywords:
- bioretention cell; enhanced denitrification and phosphorus removal; pollution load; decentralized sewage treatment
- Abstract:
- In order to explore the effects of different enhanced methods on denitrification and phosphorus removal in bioretention cell (BRC), four combined enhanced methods, namely addition of activated carbon, wire, activated carbon plus wire and catalytic iron, were introduced to explore their removal effects on COD, NH4+-N, TN and TP in BRC. The addition of activated carbon layer in the anaerobic zone could effectively improve the denitrification ability of the system, and the removal efficiency of TN increased by about 8% to 23%. Nitrification ability of the system could be promoted by adding wires between aerobic zone and anaerobic zone, and?NH4+-N?concentration in the effluent decreased by 5% to 10%. Catalytic iron (Fe0/Fe2+) could provide electron donor for denitrification and reduce?NO3--N to NH4+-N. The phosphorus adsorption capacity of the enhanced group with activated carbon layer was significantly higher than that of the experimental group without activated carbon, among which the experimental group with activated carbon and catalytic iron had the best performance. The removal efficiency of total phosphorus increased by 10% to 20%, and phosphorus was not released during the operation period (180 days). The nitrogen and phosphorus load had a significant effect on the effluent quality. When the system was operated at low load (TN of 30 mg/L and TP of 2 mg/L), the removal of total nitrogen and total phosphorus was significantly improved in the enhanced group. COD and TP concentration in the effluent could meet class Ⅳ standard of surface water, and TN and?NH4+-N could meet grade A standard of urban sewage discharge. When the system was operated at high load (TN of 60 mg/L and TP of 4 mg/L), the removal efficiencies of nitrogen and phosphorus fluctuated obviously. However, it could return to a steady state after reducing nitrogen and phosphorus load. Different enhanced methods can better increase the adaptability of BRC to water quality change, which is a feasible scheme for decentralized sewage treatment with low flow quantity.
Last Update:
2020-10-01