温度对城市生活垃圾和厌氧颗粒污泥联合厌氧发酵的影响

Effects of temperature on anaerobic fermentation of municipal solid waste combined with anaerobic granular sludge

针对无锡市垃圾填埋场堆体厌氧发酵所存在的产气率低、氨氮浓度高的问题,以无锡市生活垃圾为原料,在添加厌氧颗粒污泥的情况下,探讨了不同发酵温度下(25、35和45℃)对城市生活垃圾厌氧发酵过程中渗滤液的化学需氧量(COD)、氨氮、挥发性脂肪酸(VFA)、渗滤液产量和产甲烷量的影响。结果表明,25、35和45℃条件下氨氮的最终浓度分别为2 450、2 650和3 000 mg·L^(-1),COD的去除率分别为60.9%、85.2%和80.1%,最大产甲烷速率分别为67、552和397 mL·d^(-1),沼气中甲烷的平均体积分数分别为39.4%、66.9%和53.2%,累积产甲烷量分别为2 906、19 004和14 286mL。以上结果表明35℃条件在能够缩短发酵周期,提高甲烷产量的同时,还能在一定程度减小渗滤液氨氮浓度,有助于减轻后续渗滤液处理的压力。

To solve the problem of low gas production rate and high ammonia nitrogen concentration in Wuxi City landfill,with the assitcance of naerobic granular sludge,the effects of fermentation temperature （25,35 and 45℃） on different parameters （COD,ammonia nitrogen,VFA,pH,leachate production and methane production）during anaerobic fermentation of MSW （municipal solid waste） were investigated.The results showed that under the condition of 25,35 and 45 ℃,the final concentration of ammonia nitrogen were 2 450,2 650 and 3 000 mg·L^-1,the removal rates of COD were 60.9%,85.2% and 80.1%,maximum methane production rates were 67,552 and 397 mL·d^-1,average volume fraction were 39.4%,66.9% and 53.2%,cumulative methane production were 2 906,19 004 and 14 286 mL.The results indicated that the condition of 35 ℃ can not only shorten the fermentation period and improve the methane production,but also reduce the leachate concentration of ammonia nitrogen,resulting in lower pressure during subsequent leachate treatment.