餐厨垃圾和秸秆混合连续高温甲烷发酵研究

摘要

以餐厨垃圾和玉米秸秆(按TS1:1混合)为原料,开展了200d的连续高温发酵和40d批次产甲烷潜能与动力学实验,进料TS浓度8%,以水力停留时间15,10,8,5d的梯度变化逐级增加容积负荷.连续实验发现,在水利停留时间为5d时达到了系统酸化的极限负荷16gVS/(L·d),通过及时停止进料和投碱控制pH值,一周内有机酸浓度由4.73g/L降低到1.02g/L.当OLR为10gVS/(L·d)时,TS去除率和甲烷转化率分别为55.6%和64.5%.批次实验发现,餐厨垃圾、秸秆和混合原料的产甲烷潜能分别为448,221,268mLCH4/gVS,最大产甲烷速率常数(K)为63,45,41mLCH4/(gVS·d).通过连续和批次实验分别获得了混合原料高温甲烷发酵的工艺参数和动力学特征,为餐厨垃圾和秸秆能源化利用提供了一个有效途径.%A 200-days continuous methane fermentation experiment and 40-days batch experiment were carried out to treat mixture of maize straw and food waste at thermophilic condition. Thecontinuous reactor was operated feed with total solid 8% feedstock by shortening the hydraulic retention time (HRT) stepwise through 15, 10, 8and 5days and the heavy acidification occurred when the organic loading rate (OLR) reached 16g VS/(L·d) at HRT of 5days. Then the reactor was recovered with the volatile fatty acids decreasing from 4.73to 1.02g/L by stopping feeding for one week and maintains a neutral pH. A total solid removal efficiency and methane conversion ratio of 55.6% and 64.5% was obtained at OLR of 10gVS/(L·d). The methane production potential of food waste, straw and mixture of food waste and straw was obtained at 448, 221, 268mL CH4/gVS using a batch experiment. The maximum methane production rate of those materials was 63, 45 and 41mLCH4/(gVS·d) respectively. The results obtained in this study provided useful information for the utilization of food waste and straw for energy production.