MC1预处理对豆秸水解特性及产甲烷效率的影响

为提高大豆秸秆厌氧发酵产气性能,本文利用复合菌系MC1对灭菌秸秆(SS)及未灭菌秸秆(NSS)进行预处理,研究预处理时间对秸秆水解特性及产甲烷效率的影响。结果表明:MC1能有效降解大豆秸秆,SS经12 d预处理,其纤维素及木质素降解率分别为41.71%和29.92%,显著高于NSS(P0.05)。SS预处理体系中VFAs含量显著高于NSS(P0.05),且两者分别在预处理3 d及7 d浓度达到最高,分别为2.18 g·L~(-1)(SS)和1.52 g·L~(-1)(NSS),预示杂菌减缓了MC1对秸秆的降解速率。乙酸是预处理体系中最主要的VFAs产物,整个预处理期间SS和NSS水解液乙酸含量分别高于72.41%和56.23%。与未处理大豆秸秆相比,经过3 d预处理,SS和NSS预处理体系的甲烷累积产量分别提高了36.86%和34.27%,其最大产甲烷速率分别为21.69 mL·d-1·g-1VS和17.44mL·d-1·g-1VS,表明MC1预处理能有效提高大豆秸秆厌氧发酵性能。

Effects of MC1 pretreatment on hydrolysis characteristics and methane production efficiency of soybean straw

To improve the performance of anaerobic fermentation of soybean straw, sterilized straw(SS)and unsterilized straw(NSS)were pretreated by MC1, and the effects of pretreatment time on hydrolysis characteristics and methane production efficiency were studied. The results showed that MC1 could effectively degrade soybean straw. After 12 days of pretreatment, the degradation rates of cellulose and lignin were 41.71% and 29.92%, respectively, significantly higher than that of NSS(P<0.05). The VFAs content of the SS pretreatment system(2.18 g·L^-1)was significantly higher than that of the NSS system(1.52 g·L^-1)(P<0.05). Acetic acid was the primary VFA product in the pretreatment system, and the ratio of acetic acid and VFAs was higher than 72.41%(SS)and 56.23%(NSS), respectively. The cumulative methane yield of SS and NSS after a 3-day pretreatment increased by 36.86% and 34.27%, respectively, compared to untreated soybean straw. The maximum methane production rates of SS and NSS were 21.69 mL·d^-1·g^-1 VS and 17.44 mL·d^-1·g^-1 VS, respectively, indicating that MC1 pretreatment effectively improves the anaerobic fermentation performance of soybean straw.