垃圾渗滤液在土壤中的生物降解动态

Biodegradation of landfill leachate in soil

通过室内好氧、厌氧2种培养,研究了3种不同填埋年限垃圾渗滤液在红壤和潮土中的生物降解动态.鲜样、天井洼样、水阁样垃圾渗滤液分别为填埋0年、4～5年和12年的垃圾渗滤液.结果表明,垃圾渗滤液在前7d降解相对较快.在好氧培养条件下,红壤鲜样、天井洼样、水阁样渗滤液在前7d的表观降解率为88.9%、60.5%、25.0%;潮土中的表观降解率更大,分别为96.6%、80.4%和65.0%;7d后下降趋势均趋于平缓.在相同土壤中,填埋龄越短的垃圾渗滤液的表观降解率越大,在厌氧培养条件下的情况与此类似,但降解率不如好氧条件下高.在没有土壤介质参与的条件下(如低洼处积存的渗滤液),3种垃圾渗滤液自身降解速率均符合一级动力学方程.鲜样垃圾渗滤液降解的半衰期为12～16d,其余垃圾渗滤液降解的半衰期为20～30d.垃圾渗滤液一旦进入土壤环境,降解速率会大大加快.土壤处理垃圾渗滤液有一定的功效.

With aerobic and anaerobic incubation tests, this paper studied the biodegradation of three kind landfill leachates in acidic and calcareous soils. The leachates were collected from a landfill just receiving refuse （ fresh sample） and the landfills having received refuse for 4 - 5 years （Tianjingwa sample） and 12 years （Shuige sample）. The results showed that in the first seven days of incubation, these three landfill leachates degraded more quickly. Under aerobic condition, the apparent degradation rate of fresh sample, Tianjingwa sample and Shuige sample was 88.9% , 60. 5% and 25.0% in acidic soil, and 96.6%, 80.4%, and 65.0% in calcareous soil, respectively. Seven days after, a lower degradation rate was observed. In same test soils, the shorter the landfilling age, the higher apparent degradation rate tained under anaerobic condition, but the degradati of the leachates was. Similar results were obon rates were lower. The degradation of test landfill leachates fitted first-order kinetics model well, with a half-life of 12 - 16 days for fresh sample, and 20 -30 days for Tianjingwa and Shuige samples. Once the leachates penetrated into soil, their degradation quickened greatly, suggesting that soil treatment of landfill leachate could have definite efficacy.