猪粪与玉米秸秆混合中温发酵产气效果

Aerogenesis characteristics of swine feces mixed with corn straw under mesophilic fermentation

以猪粪及碱液预处理后的玉米秸秆为原料,在恒温35℃和料液总固体质量分数为5%的条件下,以实验室内培养的不产气厌氧活性污泥为接种物,研究猪粪与玉米秸秆不同配比(干物质比分别为1∶3、1∶2、1∶1、2∶1、3∶1和0∶1(单一猪粪))混合发酵对产气效果的影响。研究结果表明,在35℃条件下,猪粪与玉米秸秆以2∶1配比的累积产气量最大,为15 157 mL;其次是1∶1样品,累积产气量为15 088 mL。但甲烷产量最高为1∶1样品,56 d共产甲烷9 137 mL,甲烷气占总产气量的60.6%。通过对发酵过程中pH及COD的测定,证明经碱液预处理后的玉米秸秆能与猪粪混合稳定发酵,发酵前后厌氧消化液中COD的降解率可达50%以上。进一步研究分析得出,将玉米秸秆和猪粪按一定比例混合发酵不仅可以缩短发酵周期、提高产气速率,而且可以大幅提升原料的产气潜力。

Under the conditions of 35℃ and total solid mass fraction of 5%,the characteristics of gas production on different ratios of swine feces and corn straw of alkaline liquid pretreatment(dry matter ratio: 1∶ 3,1∶ 2,1∶ 1,2∶ 1,3∶ 1,0∶ 1(pure pig manure))were studied,using anaerobic activated sludge cultured in the laboratory as inoculum. The results showed that at 35℃,the gas production was biggest when the ratio of swine feces and corn straw was 2∶ 1,which was 15 157 mL,followed by 1∶ 1 sample,which was 15 088 mL. But the methane production was highest when the ratio of swine feces and corn straw was 1∶ 1,which was 9 137 mL after56 days,accounting for 60. 6% of the total gas. The measurement of pH and COD proved that alkaline pretreated corn straw mixed with swine feces can ferment steadily. The degradation rate of COD was up to 50% or more after anaerobic digestion. Further study proved that corn straw mixed with swine feces can shorten the fermentation cycle and improve the rate of gas production,and can significantly enhance the raw gas production potential.