不同渗滤液循环方式对填埋层甲烷产生的影响

通过填埋模拟柱 ,实验室研究了以我国大城市生活垃圾组成为依据的新鲜垃圾填埋层在不同渗滤液循环方式条件下甲烷产生的规律 .渗滤液循环方式包括 :原液循环、好氧预处理 (SBR)后循环、与陈垃圾出水混合后循环 .结果表明 :新鲜垃圾填埋层初期渗滤液COD、VFA浓度高 ,原液循环导致有机酸的积累 ,抑制了甲烷化进程 ;初期渗滤液经预处理控制一定COD、VFA浓度后循环 ,能够显著地缩短产甲烷滞后时间、加速甲烷化进程 ;当填埋层进入稳定的甲烷化阶段后 ,渗滤液循环才能有效地降解渗滤液中的有机污染 ,近 10 0 %地转化为填埋气体.

Effects on landfill methane production by different leachate recirculation operations

At present, comprehensive and successful study on leachate recirculation technique to degrade the organic pollutants in the fresh MSW landfill in developing country, which characterized of food waste being the main biodegradable component, is lack. In this paper, lab-scale landfill columns that simulated the fresh MSW landfill based on the MSW composition in China, effects on methane production by different leachate recirculation operations were studied. During the experimental course, leachate without any pretreatment, leachate pretreated by aerobic process (SBR) or mixed with leachate from mineralized landfill was recirculated to landfill columns respectively. The results indicate that COD and VFA concentration in leachate at the initial stages was higher. Such leachate recirculating to landfill columns directly or without any pretreatment would lead to accumulation of the volatile fatty acid (VFA) and to inhibition of methane fermentation. When leachate was pretreated to some extent then recirculating to landfill columns would greatly shorten the methane production lag phase time and speedup the methane fermentation. Only when methane fermentation is created and maintained steadily, the landfill organic pollutant can be biodegraded effectively, and nearly 100 percent of the organic pollutant is conversed to landfill gas.