基于污水厂运行数据的低温生物脱氮强化研究

Enhanced Biological Nitrogen Removal at Low-temperature Based on Operation Data of Wastewater Treatment Plants

基于太湖流域8家城镇污水处理厂的实际运行数据,结合动力学分析,探讨了低温生物脱氮的强化措施。动力学分析表明:温度对硝化、反硝化效果的影响较大,温度每降低1℃,硝化菌比增长速率和反硝化速率分别降低10%和9%。当污水厂的污泥负荷≤0.12 kgBOD5/(kgMLSS.d)、泥龄≥12 d时,出水NH3-N全面达标(GB 18918—2002一级B)。当BOD5/TN≤3时,对TN的去除效果与碳氮比呈显著正相关;而当BOD5/TN>3时,碳氮比对TN的去除效果影响较小,但此时对TN的去除效果与对NH3-N的去除效果呈显著正相关;约有50%的污水厂因原水碳源不足影响反硝化效果。最后提出了太湖流域城镇污水厂实现低温脱氮的优选参数及强化运行管理的措施。

Based on the operation data of eight municipal wastewater treatment plants located in the Taihu basin, the enhanced biological nitrogen removal （BNR） under low-temperature was studied by kinetics analysis. The results show that temperature has a large effect on nitrification and denitrification. When temperature decreases by 1% , the multiplication rate of the nitrifying bacteria and the denitrifying rate decrease by 10% and 9% , respectively. Under the conditions of sludge loading ≤0.12 kgBOD5/ （ kgMLSS · d） and sludge retention time ≥ 12 d, the effluent NH3 -N meets the first level B criteria specified in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant （ GB 18918 - 2002）. When BODs/TN ≤3, the removal efficiency of total nitrogen （TN） is positively correlated with the ratio of BOD5/TN. However, when BODJTN 〉 3, the BOD5/TN ratio does not affect TN removal, but the TN removal efficiency is positively correlated with the NH3 - N removal efficiency. About one half of wastewater treatment plants have poor BNR capability due to the insufficiency of carbon source in the influent. The optimum parameters and the enhanced measures for operation management are put forward to overcome the negative effects on nitrogen removal under low temperature.