厌氧陈腐垃圾模拟柱对渗滤液COD和NH_3-N的处理特性

通过实地钻取阿苏卫填埋场陈腐垃圾,真实模拟填埋场压实工艺,制作2种不同压实密度的陈腐垃圾模拟柱,对比研究其对渗滤液COD、NH3-N处理效果。结果表明,当模拟柱压实密度为1.09 t/m3时,渗滤液垂直运动明显;回灌此模拟柱水力负荷分别为18.6、28、37.2和46.5 L/t时,COD去除效果稳定,平均去除率达82.4%,最高去除率可达90.1%;出水NH3-N浓度均值为549.3 mg/L,且介于415～700 mg/L间变化。自循环回灌COD去除率最高仅为11.5%,NH3-N去除率最高仅为11.8%,两者去除效果不明显。因此,北方平原型填埋场进一步完善填埋工艺,使填埋场垂直方向渗透系数分布均匀,充分利用陈腐垃圾堆体的自降解能力,才是处理渗滤液污染的关键。

Decomposition behavior of leachate COD and NH_3-N in anaerobic MSW simulation column

Decomposition efficiencies of leachate COD and NH3-N in anaerobic MSW simulation column were investigated by using decomposed refuse drilled in Asuwei landfill.Experiments were carried out at two compaction density levels in combination with simulating landfill compaction process.The results showed that vertical flow of leachate was significant at the column compaction density of 1.09 t/m3.At the recharging hydraulic loading of 18.6、28、37.2和46.5 L/t,the removal efficiency of COD became stable and its average and the maximum value were 82.4% and 90.1%,respectively.Concentration of NH3-N in effluent was in the range of 415 mg/L to 700 mg/L and average value was 549.3 mg/L.The removal efficiency of COD and NH3-N in leachate selfrecirculation mode were only 11.5%,and 11.8%.Therefore,it was suggested that the fill process treatment of landfill in northern plain need to be further improved.The landfill vertical permeability uniformity and self-degradation of the garbage body are the key factors in reducing leachate pollution.