接种率及尿素添加量对农村生活垃圾厌氧发酵产甲烷的影响

为了解接种率及尿素添加量对农村生活垃圾厌氧发酵产甲烷的影响,选取3个水平的接种率(0.3、0.5、1.0)和3个水平的尿素添加量(1%、3%、5%)进行农村生活垃圾厌氧发酵实验。结果表明,在相同尿素添加量的条件下,接种率(0.3~1.0)越高越有利于甲烷产生,同时挥发性脂肪酸降解速率越快;而在相同接种率的条件下,随尿素添加量(1%~5%)的增加,甲烷产量呈先升高后降低的趋势。Gompertz动力学模型拟合结果表明,在接种率为1.0、尿素添加量为3%的条件下,厌氧发酵产甲烷延滞期较短(12 d),70 d累积甲烷产量最高(0.44 L·g~(-1)TS),发酵过程未发生酸化现象。

Effects of Inoculums Ratio and Urea Concentration on Biochemical Methane of Rural Domestic Waste with Anaerobic Digestion

In order to study the effects of inoculation ratio and urea concentration on methane production of anaerobic digestion of rural do-mestic wastes(RDW), a set batch of anaerobic digestion experiments, which chose 3 levels of inoculums ratio(0.3, 0.5, 1.0)and 3 levels of urea concentration(1%, 3%,5%), were conducted. The performances of volatile fatty acids(VFA), biogas production, methane produc-tion were investigated, and also methane production was fitted with the modified Gomopertz model to assess the characteristics of the anaero-bic digestion. The results showed that under the same concentration of urea, the higher the inoculation ratio was, the more methane was pro-duced and the faster VFAs were decomposed. Under the same inoculation ratio, the methane production showed a trend of increasing at first and then decreasing as the urea concertation increased. According to the fitting results of Gompertz kinetic model, when the inoculation ratio was 1 and urea concentration was 3%, the anaerobic digestion had the best performance.The cumulative methane production(70 d)was 0.44 L·g-1 TS, and the lag phase was only 12 d.