包气带砂层中生物作用对垃圾渗滤液中污染物的去除研究

Contamination Removal in Landfill Leachate by Biological Effect in Sand Layer of Vadose Zone

通过2个砂柱的对比实验,研究了包气带砂层中生物作用对垃圾渗滤液污染物去除的影响.实验中首先确定了HgCl2为生物作用抑制剂,最佳抑制浓度为10 mg/L.然后砂柱1采用垃圾渗滤液进行淋滤,砂柱2采用加入了10 mg/L HgCl2的垃圾渗滤液进行淋滤.实验结果表明,随着淋滤时间的延长,砂柱1中的生物作用逐渐增强;到实验结束时,垃圾渗滤液COD和BOD5的浓度分别降低了2724 mg/L和2332.5 mg/L,NH4+的含量从1282.82 mg/L上升到1745.48 mg/L,TN的去除效果并不明显;砂柱2由于生物作用受到了抑制剂的抑制作用,当垃圾渗滤液污染物质穿透砂柱后,其浓度基本保持平稳.根据实验结果得到砂柱中生物降解COD的一级衰减动力学模型.

Through the test of two sand columns for comparing, the effect on removal of pollutants in landfill leachate by biological effect in sand layer of vadose zone was studied. First, HgCl2 was confirmed as inhibitor of biological effect, and its most suitable concentration was 10 mg/L. Then, sand column 1 was leached by landfill leachate, and sand column 2 was leached by landfill leachate added 10 mg/L HgCl2 .The results indicated： with the time prolonged, the biological effect was more and more obvious. When the test was finished, the concentrations of COD and BODs respectively reduced by 2 724 mg/L and 2 332.5 mg/L, and the concentration of NH4^＋ ascended from 1 282.82 mg/L to 1 745.48 mg/L, but the effect of TN removal was not obvious. Because the biological effect was inhibited by inhibitor of HgCl2 , the concentrations of pollutants kept calm when landfill leachate penetrated the sand column. Based on the results of experiment, the first-order attenuation kinetics model of biodegradation in sand column was founded.