污水处理厂上向流反硝化滤池极限脱氮效能研究

Study on the maximum nitrogen removal efficiency of upflow denitrification filter in wastewater treatment plant

反硝化滤池作为污水处理厂一级A达标排放的保障技术,在提标改造趋势下,面临极限去除TN的挑战。中试以武汉市某污水处理厂二级出水为原水,在全年范围内对上向流反硝化滤池的极限脱氮效能进行了研究,并总结了技术应用达标(TN≤5 mg/L)的边界条件。结果表明,在进水TN为8.1~16.9 mg/L时,设计参数下的滤池出水TN达标率超过90%。其中,水温、进水TKN含量及外加碳源C/N比是制约TN稳定达标的重要因素。通过数据拟合,得出吨水乙酸钠药剂投加费用公式为:y_(乙酸钠)=0.031x_(ΔTN)+0.093。

The denitrifying filter is a key technology for effluent from city wastewater treatment plant(WWTP)to meet the"The first level A"discharge standard of Discharge standard of pollutants for municipal wastewater treatment plant(GB 18918-2002).However,the denitrifying filter is facing the challenge of depth nitrogen removal with the improvement of wastewater discharge standard.To obtain the boundary conditions for WWTP meeting effluent discharge standard of TN≤5 mg/L,a pilot scale study on the maximum denitrification capacity of upflow denitrification filter in a WWTP in Wuhan was carried out.After one-year operation under the set condition,the results showed that more than 90%effluent meet the discharge standard(TN≤5 mg/L)when the TN concentration in the influent was 8.1~16.9 mg/L.Additionally,water temperature,the concentration of total kjeldahl nitrogen(TKN),and C/N ratio are the key parameters affecting the concentration of TN in the effluent.Through the analysis of actual operation and data,the calculation formulae for addition cost of sodium acetate per ton was obtained:y_(sodium acetate)=0.031x_(ΔTN)+0.093.