反硝化生物滤池脱氮的中试研究

Pilot Study on Denitrification Biofilter for Nitrogen Removal

以某城市污水厂初沉池出水为原水,采用中试规模的移动床生物膜反应器/沉淀池/反硝化生物滤池工艺进行生物脱氮,重点考察了反硝化生物滤池的脱氮效果及C/N值对脱氮效率的影响,探讨了反硝化生物滤池再启动后的恢复情况,并构建了反硝化生物滤池脱氮动力学模型。结果表明,在稳定运行期间反硝化生物滤池对TN的去除率为86.4%~96.5%,当2.5<C/N值<5时,TN去除率与C/N值无相关性,平均去除率为93.3%,最佳C/N值为3.45。反硝化生物滤池经过3 d维护后再启动,运行12 h后即可恢复到滤池维护前的脱氮水平。在该中试条件下,反硝化遵循零级反应动力学,反应速率为174.4 mg/(L·h)。

The effluent from the primary settling tank of a municipal wastewater treatment plant was selected as the raw water, and a pilot scale experiment of the moving bed biofilm reactor/sedimenta- tion tank/denitrification biofiher process was conducted for biological nitrogen removal. The nitrogen re- moval efficiency of denitrification biofiher as well as the effect of C/N ratio on the removal of total nitro- gen were investigated, the recovery of denitrification biofiher after restart was discussed, and the denitrifi- cation kinetic model was built. The results showed that the removal of TN reached 86.4% to 96.5% in the stable period, the removal of TN had no correlation with C/N ratio when C/N ratio was between 2.5 and 5, the average removal of TN was 93.3%, and the optimum ratio of C/N was 3.45. After main- tained for 3 d, another 12 h was needed to restore the removal efficiency of TN. Under the pilot scale conditions, denitrification followed zero-order kinetics, and the value was 174.4 mg/（ L ·h）.