前置反硝化-曝气生物滤池低温脱氮效能中试研究

Pilot Scale Study on Nitrogen Removal Efficiency of Predenitrification Biological Aerated Filter Under Low Temperature Condition

当污水温度低于15℃时,对生物脱氮的硝化和反硝化环节都会产生显著的抑制作用。理论上,延长污泥龄有利于提高胁迫条件下生物脱氮效率。以采用沈阳仙女河污水处理厂初沉池出水为原水,构建了1.5 m^3/h前置反硝化-曝气生物滤池中试规模工艺体系,在越冬时节(进水温度11~20℃)运行了114 d。研究发现,当气水比为6:1,回流比为150%,乙酸钠投加量为50 mg/L时,前置反硝化-曝气生物滤池出水的化学需氧量(COD)、NH_4^+-N、总氮(TN)和悬浮物浓度(SS)能够达到我国现行的城镇污水处理厂污染物排放标准中的一级A标准,并具有低耗运行的潜力。

The nitrification and denitrification will be inhibited evidently if the water temperature is lower than 15 ℃. However, prolonging the sludge retention time is beneficial to improve the efficiency of biological denitrification under stress condition in theory. Taking the primary sedimentation tank effluent of Shenyang Fairy River wastewater treatment plant （WWTP） as the influent, a pilot-scale predenitrification biological aerated filter was built in winter （11-20 ℃）, which was operated for a period of 114 days with 1.5 m3/h. The chemical oxygen demand （COD）, NH4＋-N, total nitrogen and suspended solids of the effluent can reach the current ＂urban sewage treatment plant pollutant discharge standard＂ level A when the gas water ratio was 6：1, the reflux ratio was 150% and the sodium acetate dosage was 50 mg/L. Predenitrification biological aerated filter has low power consumption potential and provides a new way for the transformation of north sewage treatment plant.