多元混合物料协同促进厌氧消化产甲烷性能试验研究

摘要

为评估农牧废弃物多元物料混合厌氧发酵对产甲烷性能的协同促进作用,研究了中温(37±1)℃和固体质量分数为12%时,牛粪、蔬菜废弃物和玉米秸秆混合原料的厌氧消化产甲烷性能,最后应用修正的Gompertz方程分析甲烷生产的动力学过程.结果表明:3种物料混合厌氧发酵发生了明显的协同促进作用,协同效应作用值为34.85%~70.39%,贡献效果显著(P<0.05);当牛粪、蔬菜废弃物和玉米秸秆VS混合比例为50:20:30时,甲烷产率、累计甲烷产量和VS降解率达到最大值,分别为286.0mL/g VS、20713mL和65.6%,比单一牛粪、蔬菜废弃物以及玉米秸秆厌氧消化甲烷产量分别提高了32.9%、229.9%和82.0%.修正的Gompertz方程能较好反映物料厌氧消化产甲烷过程,拟合结果的R2均大于0.99,牛粪、蔬菜废弃物和玉米秸秆VS比例为50:20:30时具有最大产甲烷速率17.34mL/(d?g)和较短的迟滞时间2.97d.该研究结果可为农牧废弃物多元混合物料厌氧消化产沼气工程提供参考.%In order to evaluate the synergistic effects of multiple raw materials anaerobic co-digestion of agricultural and livestock wastes on methane production performance, the tests were conducted under the condition of solid-state (12% total solids) and mesophilic (37±1)℃ to investigate multiple raw materials on methane production performances of anaerobic digestion, and then the dynamic characteristics of producing methane process were analyzed by the modified Gompertz equation. The results showed that synergistic effects obviously occured during the anaerobic co-digestion of three substrates, the synergistic effect of co-digestion contributed to methane yield was significantly (P<0.05) increased by 34.85%~70.39%. A 50:20:30VS ratio of cow manure, vegetable waste and corn straw produced the highest methane yield of 286.0mL/g VS, the highest cumulative methane of 20713mL and the highest VS removal efficiency of 65.6% due to the synergistic effect, increased by 32.9%、229.9% and 82.0% comparing with the cow manure, vegetable waste and corn straw mono-digestion of methane production rate respectively. The analysis results of modified Gompertz equation indicated that the model had feasibility to describe the dynamic process of anaerobic digestion, the R2 values of the fitting curves were larger than 0.99. The maximum methane production rate and the shorter lag phase (17.34mL/(d?g)and 2.97d) were achieved from co-digestion of cow manure, vegetable waste and corn straw at mixing ratio of 50:20:30. The experimental study can provide a reference for biogas projects of multiple raw materials anaerobic co-digestion of agricultural and animal husbandry wastes.