两级曝气生物滤池对垃圾渗滤液的脱氮效果

Pilot Study on Nitrogen Removal from Landfill Leachate by Two-stage Biological Aerated Filter

经过生化工艺处理后的垃圾渗滤液，其总氮含量仍然很高，往往难以达标排放。采用中试规模的两级曝气生物滤池（BAF）对垃圾渗滤液进行深度处理，研究了滤层与其工作性能的关系。结果表明，两级BAF工艺对COD的去除率稳定在80％以上，出水NH3-N可以保持在3mg／L以下。当HRT为8h左右、进水温度为20～26℃、气水比为5：1、BAF2出水以回流比为1：1回流至BAF1时，由下至上的各区间段对COD和NH3-N的去除率与滤层高度呈正相关。中部进气使得两级BAF工艺对COD和NH3-N的去除主要集中在下部和中部区域，上部对COD和氨氮的去除作用微弱。

Due to still high TN concentration, the landfill leachate treated by biochemical process is often difficult to meet the discharge Standard. The pilot＇scale two＇stage biological aerated filter （BAF） was used for advanced treatment of the landfill leaehate, and the relationship between filter layer and the performance was investigated. The results show that the removal rate of COD is stabilized at more than 80% , and the effluent NH3 - N is maintained below 3 mg/L. Under the conditions of HRT of 8 h, influ, ent temperature of 20 to 26 ℃, air-water ratio of 5 ： 1, effluent return ratio of 1 ： 1 from BAF2 to BAFI,there is a positive correlation between the height of the filter layer and the removal rates of NH3^ - N and COD in the zones from bottom to top. The way of central air intake makes the major parts of NH3^ - N and COD to be removed at the bottom or the middle of the two-stage BAF, and little part of NH3^ - N and COD are removed in the top.