褐铁矿与固体含量对牛粪秸秆混合厌氧干式发酵的影响

干式厌氧发酵是处理农业废弃物的有效途径之一，其中总固体（TS）含量和外源添加剂是影响有机质产甲烷过程的重要影响因素。以牛粪与水稻秸秆为例，研究了不同的褐铁矿添加量以及TS含量对牛粪秸秆混合厌氧干式发酵产甲烷过程的影响，并对沼渣特性进行表征。结果表明：固定TS含量25%时，添加1%褐铁矿（基于底物TS含量）显著促进产甲烷过程，产气量比对照组增加了21 mL·g-1（以VS计）；对照组（无褐铁矿）和添加1%褐铁矿时，纤维素降解均随TS含量升高而降低；TS含量40%时，添加1%褐铁矿对产甲烷过程具有抑制作用，甲烷产率相比于对照组（TS含量25%）降低了71%。可见只有当TS含量25%时，添加适量褐铁矿才能有效促进牛粪秸秆混合厌氧发酵产甲烷过程。研究可为优化农业废弃物甲烷化提供参考。

Effect of limonite and solid content on dry anaerobic co-fermentation of rice straw and manure

Dry anaerobic fermentation was one of the effective ways to deal with agricultural waste. The total solid (TS) content and exogenous additives were the important factors affecting the process of methane production. Therefore, in the process of mixed anaerobic dry fermentation of cow manure and straw, the influences of different limonite addition and TS content on the methane-production process were investigated, and the characteristics of biogas residue were characterized as well. The results showed that when the content of TS was 25%, the addition of 1% limonite (based on the content of substrate TS) significantly promoted the methane-producing process, the gas production volume increased by 21 mL·g-1(based on VS) compared with the control group. Furthermore, in the control group (no limonite) and the group with 1% limonite addition, cellulose degradation was decreased with the increase of TS content. When TS content was 40%, the addition of 1% limonite had inhibitory effect on methane-producing process, and the yield of methane was 71% lower than that of the control group (25% TS content).