蔬菜类废弃物甲烷发酵的产气潜能及过程特征  

Biogas production potential and process character of methane fermentation of vegetable waste

作　　者：宋亚楠 宋梓梅 裴梦富 贾雪雪 强虹[1] 

机构地区：[1]西北农林科技大学资源环境学院,杨凌712100

出　　处：《环境工程学报》2018年第2期645-653,共9页Chinese Journal of Environmental Engineering

基　　金：国家自然科学基金资助项目(51308460)

摘　　要：蔬菜废弃物具有适合厌氧发酵的特性。采用Batch实验方法,对5种常见的蔬菜废弃物的产气潜能进行研究,并在此基础上进一步对厌氧发酵过程限制性步骤及物质转化特征进行分析。研究结果表明:5种蔬菜废弃物累积产甲烷量在发酵0~10 d内增加较快,土豆和白菜废弃物产甲烷潜能最大,分别达到102 mL·g^(-1)(VS),和83 mL·g^(-1)(VS),而黄瓜废弃物的甲烷化潜能较低,只有35 mL·g^(-1)(VS)左右。动力学参数拟合表明:土豆和白菜废弃物厌氧发酵水解、酸化、乙酸化和甲烷化各过程转化速率都明显高于其他废弃物,并且各过程最大转化潜能也较其他类蔬菜高出2倍之多。厌氧发酵限制性步骤分析表明,快速水解生成的SCOD不能有效地转化为VFAs,限制了白菜废弃物厌氧消化的后续转化,而VFAs的累积则是胡萝卜、黄瓜和土豆废弃物厌氧发酵的限制性步骤,SCOD以及VFAs同时累积是茄子废弃物发酵过程的显著特征。对各物质发酵过程物质转化特征分析表明,各废弃物由于4 d以后甲烷菌对乙酸的利用减慢,导致丙酸向乙酸的转化减慢而发生累积现象,10 d以后由于产酸过程的减弱,累积的丙酸盐逐渐转化。Vegetable wastes are the promising source for methane fermentation.The aim of this present study to examine the biogas production by using five common vegetable wastes by batch test.Furthermore,the rate-limiting step and the characteristics of substance transform during methane fermentation were further analyzed.Results revealed that the cumulative methane production of five vegetable wastes evidently increased rapidly within 10 days.However,the highest methane production was obtained by potato and Chinese cabbage wastes,which were 102 mL·g^-1（VS） and 83 mL·g^-1（VS）,respectively.On the other hand,the lowest methane production was received by cucumber waste down to 35 mL·g^-1（VS）.Consequently,kinetics analysis exposed that the rates of hydrolysis,acidification,acetification and methanation of potato and Chinese cabbage were higher than other vegetable wastes,the maximum conversion potential of them in each stage of methane fermentation was twice as much as others.The results of the staged character analysis on the rate-limiting step showed that the SCOD from rapid hydrolysis of Chinese cabbage was not highly effective to convert in VFAs during fermentation stages,but the conversion of the accumulative VFAs to acetic acid was the rate-limiting step of carrot,potato and cucumber.Moreover,eggplant considerably enhanced the accumulation of SCOD and VFA at the same time were characterized.In addition,the result of the matter transformation characteristics analysis during methane fermentation indicated that propionic accumulation which was evidently observed after 4 days in each waste due to the descent of the conversion rate of acitic acid to methane,after 10 days,the accumulated propionate content whichwas gradually degraded because of the reduction in acidogenesis process.

关 键 词：蔬菜类废弃物 甲烷发酵 产气潜能 限速步骤 物质转化 

分 类 号：X705[环境科学与工程—环境工程]