接种物种类对玉米秸秆沼气干发酵过程的影响

Effects of different inoculums on solid state anaerobic digestion of corn stover

以玉米秸秆为原料,分别以液态牛粪沼气发酵的剩余物及玉米秸秆沼气干发酵的沼渣为接种物进行沼气干发酵试验.秸秆与接种物之比(F/I,基于可挥发性固形物VS)分别为1、3、5,研究了接种物种类和接种量对沼气干发酵过程的启动速度、累积产气量以及微生物菌群结构变化等的影响.试验结果表明:接种液态牛粪沼气发酵剩余物的发酵罐的启动速度及累积产气量均明显优于以玉米秸秆沼气干发酵沼渣为接种物的发酵罐.以液态牛粪沼气的沼渣做接种物时,接种量F/I=1、3、5时的总产气量差异不显著(p>0.05);用秸秆干发酵沼渣做接种物时,F/I=1的发酵罐能正常启动,但累积产气量为66.9 L·kg-1(以VS计),比接种液态牛粪沼气发酵剩余物的发酵罐低26%.而F/I=3和5的发酵罐则由于过度酸化而导致发酵失败.

Using corn stover as the raw material,we investigated the effects of two inoculums including residues from liquid state anaerobic digester(LAD) dealing with dairy manure and solid state anaerobic digester(SS-AD) dealing with corn stover.Furthermore,with the feedstock to inoculum ratios(F/I ratio,based on volatile solid) of 1,3 and 5,the effects of two inoculums on the startup performance,cumulative biogas yield and communities of methanogens were studied during SS-AD.Results showed that the startup performance and cumulative biogas yield inoculated with L-AD residue were higher than that inoculated with SS-AD residue.Inoculated with L-AD residue,the cumulative biogas yields have no significant difference(p> 0.05) at different F / I ratios.Inoculated with SS-AD residue,the reactors with F / I = 1 performed well,but the accumulative biogas yield(66.9 L·kg-1) was 26%lower than that of the reactors inoculated with L-AD residue.Reactors with F / I = 3 and F / I = 5 failed due to excessive acidification.