酸碱预处理辣椒秸秆与羊粪混合厌氧发酵特性

Effect of acid and alkali pretreatment on anaerobic co-digestion characteristics of pepper straw and sheep manure

为实现辣椒秸秆等农业废弃物的资源化利用,通过批式厌氧发酵试验,分别研究了经不同体积分数(2%、4%、6%、8%)的H_(2)SO_(4)和不同质量分数(2%、4%、6%、8%)的Ca(OH)_(2)预处理的辣椒秸秆与羊粪混合厌氧发酵的产甲烷特性。结果表明,随着预处理中Ca(OH)2质量分数的升高,辣椒秸秆与羊粪混合厌氧发酵的甲烷产率升高,经8%Ca(OH)_(2)预处理的甲烷产率最高(188.56 mL·g^(-1)),显著(P<0.05)高于其他处理,较对照提高了61.26%。但随着预处理中H2SO4体积分数的升高,辣椒秸秆与羊粪混合厌氧发酵的甲烷产率降低,且显著(P<0.05)低于对照。利用修正的冈珀茨(Gompertz)模型能较好地拟合各处理的产甲烷过程,其中,经Ca(OH)_(2)预处理的最大甲烷产率(Vm)值较大,说明Ca(OH)_(2)预处理辣椒秸秆能有效提高其与羊粪混合发酵的水解速率。酸、碱预处理均对辣椒秸秆木质纤维素有一定的降解作用,其中,Ca(OH)_(2)预处理的降解效果更好。

To realize resource utilization of agricultural wastes,batch anaerobic fermentation experiments were performed to compare the effects of H_(2)SO_(4) pretreatment(volume fraction of 2%,4%,6%,8%)and Ca(OH)_(2) pretreatment(mass fraction of 2%,4%,6%,8%)of pepper straw on the characteristics of methane production during anaerobic co-digestion of pepper straw and sheep manure.It was shown that methane yield in the anaerobic fermentation increased with higher Ca(OH)_(2) mass fraction in the pretreatment,and the maximum methane yield of 188.56 mL·g^(-1) was achieved with 8%Ca(OH)_(2) pretreatment,which was significantly(P<0.05)higher than those of the other treatments,and the methane yield was 61.26%higher than that of control.In contrast,the increased volume fraction of H_(2)SO_(4) in pretreatment resulted in reduced methane yield,all of which were significantly(P<0.05)lower than that of control.The modified Gompertz model could fit the methanogenesis process.The maximum methane yield(Vm)was higher with Ca(OH)_(2) pretreatment,which indicated that the pretreatment of pepper straw with Ca(OH)_(2) could effectively increase the hydrolysis rate.Moreover,both acid and alkali pretreatment exhibited a certain degradation effect on the lignocellulose of pepper straw,yet Ca(OH)_(2) pretreatment showed higher degradation effect.