垃圾预处理条件对渗滤液组分及其微生物燃料电池处理效果的影响

在实际生产生活中,城市垃圾焚烧或热解处置前一般需经过7~10 d的堆放预处理,预处理可去除垃圾中部分水分、提高垃圾热值,对于垃圾处理质量、热能回收、污染物排放等有着重要的影响。因此,本实验详细跟踪了城市垃圾预处理条件如堆放温度、堆放时间等对城市垃圾含水率、渗滤液产生量和渗滤液组分的影响,并进一步考察了其对渗滤液微生物燃料电池处理效果的影响。垃圾堆放温度实验结果显示,当垃圾堆放于40℃时效果最佳,此时垃圾减重率适中,所得的渗滤液中B/C比约为0.31、氨氮浓度约为1560 mg·L^-1,适宜生化处理。此条件下所得的渗滤液经MFC处理时电池可获得0.29 V的输出电压,且经7 d处理后渗滤液中COD、氨氮去除率可分别达66.2%和87.2%。随后,在最佳堆放温度下进一步考察堆放时间的影响。结果显示,在最佳堆放温度40℃下,垃圾堆放6 d后所得的渗滤液组分最易于生化处理,其B/C比约为0.32、氨氮浓度约为1520 mg·L^-1,经MFC处理时电池可获得0.29 V的输出电压,且经7 d处理后渗滤液中COD、氨氮的去除率分别为62.7%、87.6%。综上所述,40℃下堆放6 d是城市垃圾焚烧或热解处置预处理的最佳条件,此条件下,垃圾减重率和渗滤液产生量适中,且所得渗滤液可生化性较强,适合用于MFC产电处理。

Effects of pretreatment condition of MSW on components of leachate and result of MFC treatment

For an actual process of production,7—10 days pre-stack treatment,which could remove partial water and improve calorific value of municipal solid waste(MSW),is generally required prior to its incineration or pyrolysis.The pre-treatment has significant impacts on the quality of waste disposal,energy recovery and pollutants emissions.In this study,the effects of pretreatment conditions of MSW on components of leachate and result of MFC treatment were investigated.It was found that the optimal pretreatment condition for MSW prolysis was:6 days stacking at 40℃.In that case,the weight of MSW lost by 30%,the concentrations of BOD and NH₄⁺-N as well as the B/C value in the leachate were 20800 mg·L^-1,1410 mg·L^-1,and 0.32 respectively,and the content of nutrient materials was suitable for biochemical treatment.In addition,when MFC was employed for treating the leachate,the maximum output voltage could achieve 0.29 V,and the cell operated continuously 7 days,69.4% of BOD and 87.6% of NH₄⁺-N in the leachate could be removed.