猪粪秸秆不同物料比对固体产酸发酵效果的影响

在沼液回流的条件下，研究猪粪和秸秆固体产酸发酵过程中，不同原料配比（猪粪与秸秆质量比分别为4︰1、2︰1、1︰1、1︰3和0︰1即纯秸秆）对产酸发酵效果的影响。试验结果表明：增加发酵原料猪粪比例有利于调节发酵体系pH值，但酸化液中氨氮质量浓度较高；沼液回流能有效避免体系过酸现象；上述不同原料质量配比产酸发酵产物以乙酸为主，试验周期内，累积产乙酸质量分别占各反应器挥发性脂肪酸（VFAs）总质量的80.8%、81.8%、77.1%、78.3%和73.8%，酸化液中丙酸质量浓度均低于1.6 g/L，累积产生质量分别占各反应器VFAs总质量的4.8%、2.8%、7.2%、6.5%和8.4%。综合分析表明，猪粪与秸秆比为2︰1时，发酵过程中产酸效果优于其他配比试验。

Effects of different ratios of pig manure and straw on solid acidogenic fermentation

In this study, the effect on solid acidogenic fermentation of different proportion with pig manure and straw under the condition of biogas slurry returning were investigated. For this purpose, five sets of anaerobic batch reactor experiments were performed using straw and the mixtures of pig manure and straw in five different ratios (80% pig manure, 20% straw; 66.7% pig manure, 33.3% straw; 50% pig manure, 50% straw; 25% pig manure, 75%straw; 100% straw). The results showed that increasing the proportion of pig manure done well for controlling pH value, but the higher concentration of ammonia nitrogen appeared simultaneously. Returning of biogas slurry could avoid cumulating of VFAs effectively. Acetic acid which was dominant in fermentation products of different raw material ratios experiments accounted for 80.8%, 81.8%, 77.1%, 78.3% and 73.8% respectively of total output VFAs. Propionic acid concentrations in five reactors were less than 1.6 g/L, and accounted for 4.8%, 2.8%, 7.2%, 6.5% and 8.4% of total VFAs produced respectively. Comprehensive analysis showed that 2:1 ratio of pig manure to straw was better for acidogenic fermentation than other treatments.