不同填料粒径BAF深度处理城市污水的研究

Study on Advanced Treatment of Municipal Wastewater by BAF with Different Media Sizes

采用填料粒径不同的两种曝气生物滤池（BAF）深度处理城市污水厂的二级出水，考察了填料粒径、水力负荷、填料高度等参数对处理效果的影响。结果表明，在水力负荷为1～3m／h、进水CODMn为5～17mg／L的条件下，两BAF反应器的出水CODMn均稳定在5mg／L以下，且提高水力负荷有利于对CODMn的去除；填料粒径较小的BAF对氨氮的去除效果比填料粒径较大的要好，且填料粒径对氨氮去除效果的影响随水力负荷的增加而愈加明显；填料柱（上向流）的前50cm主要去除CODMn，而对氨氮的去除主要发生在50cm以后。

Two kinds of biological aerated filters （BAF） with different media sizes were applied for advanced treatment of the secondary effluent of municipal wastewater treatment plant. The effects of media size, hydraulic loading and media height on the treatment efficiency were investigated. The results show that when the hydraulic loading is 1 to 3 m/h and the influent CODMn is 5 to 17 mg/L, the effluent CODMn of the two filters is less than 5 mg/L, and increasing hydraulic loading is beneficial for removal of CODMn. The removal efficiency of ammonia nitrogen by BAF with smaller media size is better than that by BAF with bigger media size. The effect of media size on the removal of ammonia nitrogen is more and more significant with the increasing of hydraulic loading. The first 50 cm of media column mainly removes CODMn, and the removal of ammonia nitrogen mainly occurs at later 50 cm of media column.