牲畜粪便与麦秆混合厌氧发酵的产气量、发酵时间及最优温度

探索牲畜粪便与作物秸秆混合发酵的产气量和发酵时间与发酵温度之间的关系，是解决农村户用沼气原料选择、确定最优发酵温度和提高农作物秸秆资源化利用效率的关键.采用可控型恒温发酵装置，以猪粪、牛粪和麦秆作为发酵原料，以常温厌氧发酵池的底物为接种物，在总固体（total solid，TS）质量分数为8%的条件下进行批量试验，研究了混合发酵的产气量、发酵时间及最优温度.结果表明：粪便与麦秆混合发酵明显提高了原料的产气效率，其中猪粪与麦秆混合发酵的累积产气量比猪粪作为单一发酵原料高24倍，而牛粪与麦杆混合发酵的累积产气量与单一牛粪无显著差异.猪粪、牛粪与麦秆混合发酵的最优温度均在30 ℃以上，发酵时间在60 d左右.厌氧发酵的发酵时间不总是随着温度的升高而缩短，单一以温度来断定厌氧发酵时间的长短是不可行的.

Biogas yield and its relations with the duration and temperature of mixed anaerobic fermentation of livestock dungs and wheat straw.

To approach the relationships between the biogas yield of mixed anaerobic fermentation of livestock dungs and crop straw and the fermentation duration and temperature is the key of selecting fermentation materials for rural household biogas, determining optimal fermentation temperature, and improving the reuse efficiency of agricultural residues. In this paper, a batch of experiments under the condition of 8% mass fraction of total solid were conducted in a self manufactured anaerobic fermentation reactor, with pig dung, cattle dung, and wheat straw as fermentation materials, and the substrate of constant temperature fermentation pool as inoculation substance. The biogas yield, fermentation duration, and optimal temperature were determined. It was shown that the cumulative biogas yield of mixed anaerobic fermentation of pig dung and wheat straw was 2.4 times higher than that of the fermentation of pig dung alone, but no significant difference was observed between the cumulative biogas yields of the mixed fermentation of cattle dung and wheat straw and the fermentation of cattle dung alone. The optimal fermentation temperature for the mixed anaerobic fermentation was above 30 ℃, and the fermentation duration was about 60 days. The fermentation duration was not always shortened by increasing temperature, and it would be not feasible to only use temperature to determine the duration of anaerobic fermentation.