蚕沙沼气发酵条件初步研究

Study on the Conditions of Silkworm Excrement Fermentation

采用L9(34 )正交设计法 ,对影响蚕沙沼气发酵的基质浓度、原料配比、pH值、接种物种类等主要因素的综合效应进行了初步研究。结果表明 ,在自然温度及C N为 2 5 1条件下 ,原料配比和适当的pH值是确保蚕沙沼气发酵正常进行的关键。从中优化出蚕沙沼气发酵的基本条件为 :蚕沙与猪粪比为 1∶1,pH值在中性或微酸性范围 (6 .5 ) ,用沼池底部污泥作接种物 (接种量 10 %) ,基质浓度为 6 %～ 10 %范围。在上述条件下 ,蚕沙与猪粪混合进行沼气发酵启动 1d后开始进入正常状态 ,12 0d的日均产气量比纯蚕沙增加 12 6 %,沼气中的CH4 含量达 71.2 %,比对照提高 4 0 .2 %。

L_9(3~4)orthogonal cross was used to study the effect of material concentration, proportion of different materials, pH,kinds of inoculation,on silkworm excrement fermentation. The result showed that the proportion and pH of material were the most important factors for the normal fermentation ofsilkworm excrement. An optimal condition is that the ratioofsilkworm excrement to pig turd is 1∶1; range of pH is from slightly acidic to slightly basic(around-6.5); the sludge at the bottom of the digester is used for inoculation; the concentration of substrate material is 6% or so. In such condition, fermentation could go normal after 1-day of start-up. Comparing with the control,the gas production increased by 126% after 120 days.CH_4 concentration of biogas was 71.2%,which was 42.2% higher than the control.