曝气频率对生物反应器渗滤液与填埋气的影响  

Effects of aeration frequency on leachate and landfill gas in bioreactor landfill

作　　者：田颖[1] 王珅[1] 徐期勇[1] 

机构地区：[1]北京大学深圳研究生院环境与能源学院聚硅酸盐复合环保材料工程实验室,深圳518055

出　　处：《环境工程学报》2015年第1期207-212,共6页Chinese Journal of Environmental Engineering

基　　金：教育部博士点新教师基金资助(20110001120114);深圳市科技计划项目(CXB201105100085A,JC201104210129A)

摘　　要：传统生物反应器填埋场长期以来存在酸化阶段过长和能源回收利用率低等问题。上层垃圾好氧处理可有效实现垃圾快速降解与集中甲烷化。为探究好氧处理阶段不同曝气频率对生物反应器填埋场运行效果的影响,设置厌氧生物反应器A1作为对照,曝气频率不同的上层曝气式生物反应器C1和C2为实验组进行实验。结果表明,上层垃圾好氧处理可有效改善填埋柱内高浓度挥发性脂肪酸(VFA)累积现象,缩短酸化阶段,促进甲烷化环境建立。至曝气结束,C1和C2填埋柱内渗滤液COD低于30 000 mg/L,VFA浓度降也降低到10 000 mg/L以下。好氧处理阶段,增大曝气频率可提高填埋垃圾对渗滤液p H的缓冲作用,扩大甲烷化面积,促进高浓度甲烷化过程的快速发生。与C1相比,曝气频率较高的C2反应器提前15 d达到p H为7的预处理要求,曝气阶段氨氮浓度经历先上后下,填埋柱日产甲烷量700 m L,约为C1产气能力的2倍。但考虑到实际氧气利用率与经济性能问题,曝气频率的选择不宜过大。Traditional bioreactor landfills tend to result in long time of acidogenesis phase and low recovery efficiency of landfill gas. Recently developed bioreactor landfill technology using aeration pretreatment in the upper layer of waste could accelerate refuse degradation rate and methane production. In order to figure out the effects of aeration frequency on bioreactors' performance,three columns were built up in this experiment,including an anaerobic bioreactor A1 and two simulated bioreactors C1,C2 with different aeration frequency in the upper layer. Results show that aeration pretreatment can accelerate the degradation of organic matters and reduce accumulation of high VFA concentration. At the end of aeration operation,COD and VFA concentration in C1 and C2 reduce to less than 30 000 mg / L and 10 000 mg / L,respectively. What's more,in the aeration pretreatment period,higher aeration frequency can improve buffering capacity of waste layers and shorten acidogenesis phase.Also,methanogenic phase in bioreactor with higher aeration frequency can be developed in a shorter time.Through aeration operation,leachate p H in C2 reaches to above 7. 0 15 d earlier than C1. And ammonia concentration during aeration pretreatment phase gradually declines after reaching a peak,while C1 keeps going up. Furthermore,after switching to anaerobic bioreactors,approximately 700 m L / d methane in C2 can be generated,which are almost double that produced in C1. However,considering the rate of oxygen consumption and economic performance,over air supply is not preferred.

关 键 词：填埋 城市生活垃圾 上层曝气 曝气频率 

分 类 号：X703[环境科学与工程—环境工程]