沸石与炉渣组合材料吸附农村生活垃圾渗滤液的效能及机理研究

Research on adsorption efficiency and mechanism of zeolite and slag for rural solid waste leachate

选取沸石和炉渣作为吸附材料,探究单一材料下吸附时间、吸附剂投加量、渗滤液初始pH值对农村生活垃圾渗滤液吸附效能的影响及其机理.确定各因素最优值后,探究组合材料下吸附效能的优化条件.综合考虑试验结果,可操作性及运行成本,吸附时间120 min、吸附剂投加量为50 g·L^(-1)、渗滤液初始pH值为自然值的条件下,沸石对渗滤液中CODCr、NH_3-N、TN、TP的去除效果较好,去除率分别为37.54%、62.91%、34.48%和27.73%,炉渣对重金属Cr、As、Cd、Ni、Pb的吸附效果较好,去除率分别为81.79%、35.99%、97.26%、74.89%和91.19%.多种吸附作用中化学吸附占主导作用.组合材料对渗滤液常规污染物的去除效率较单一材料提升不大,对重金属的去除效率保持了很高的性能,实际中可考虑采用沸石与炉渣滤池串联的形式实现对渗滤液常规污染物及重金属的高效去除.

In this study,the effects of contact time,initial pH and adsorbent dosage on adsorption efficiency and its adsorption mechanism of zeolite and slag were investigated in batch experiments. Moreover,the optimality condition of the composite adsorbent for rural landfill leachate was also investigated.Under the condition of the contact time of 120 min,adsorbent dosage of 50 g·L-1,initial leachate pH of natural value,the removal efficiency of zeolite for normal pollutants（ CODCr,NH3-N,TN,TP） in leachate was better,which the removal rates were 37. 54%,62. 91%,34. 48% and 27. 73%,respectively. The removal efficiency of slag for heavy metals（ Cr,As,Cd,Ni and Pb） was more preferable,and the removal rates were 81. 79%,35.99%,97.26%,74.89% and 91.19%,respectively. The chemisorption was the dominant mechanism. There was no obvious improvement for removal efficiency of CODCr,NH3-N,TN,TP,while it kept a high removal performance for heavy metal. Accordingly,a combined filter filled with zeolite and slag in series could be used for efficient removal of leachate pollutants.