反硝化深床滤池在一级A提标项目中的应用及运行效果

海宁丁桥污水处理厂原有一、二期工程主体工艺为SBR,三期工程主体工艺为A^2O,运行中出水TN、TP和SS达不到钱塘江流域要求的一级A排放标准。提标工程在现状流程后增加反硝化深床滤池深度处理工艺以强化脱氮除磷及去除SS。实际运行时因进水溶解氧几近饱和,脱氮消耗的外加碳源远大于理论值,所以不再外加碳源,出水水质也能达到一级A排放标准。出水TP、TN、SS、NH3-N、BOD_5和COD最大浓度分别为0. 31、12. 70、7. 00、3. 05、6. 0、43. 7 mg/L,平均去除率分别为40. 11%、6. 20%、35. 03%、69. 32%、33. 33%、14. 08%,表明反硝化深床滤池去除总氮效果一般,但对TP、SS、NH_3-N的去除效果很好。

Application and Operation Performance of Denitrification Deep-bed Filter in Upgrading Project for First Class A Level Criteria

The original main process of the first and second phase of the Haining Dingqiao wastewater treatment plant was SBR, and the main process of the third phase was A^20. The effluent TN, TP and SS could not meet first class A level criteria required by Qiantang River basin. In the upgrading project, denitrification deep-bed filter was added after the current treatment process to enhance nitrogen, phosphorus and SS removal. In actual operation, as the raw water DO was almost saturated, the additional carbon source consumed by denitrification was much larger than the theoretical value. So the effluent quality still could reach the first class A level criteria without addition of carbon source. The maximum concentrations of effluent TP, TN, SS, NH3-N, BOD5 and COD were respectively 0. 31 mg/L, 12. 70 mg/L, 7. 00 mg/L, 3. 05 mg/L, 6. 0 mg/L, 43. 7 mg/L, and the average removal rates were 40. 11 %, 6.20%, 35. 03%, 69. 32%, 33. 33%, 14. 08%, respectively. The results showed that the denitrification deep-bed filter had powerful performance on TP, SS and NH3 - N removal, while the removal effect of TN was general.