堆肥预处理对麦秸与奶牛废水混合物厌氧产沼气的影响

摘要

Effect of composting pretreatment time on biogas production of the mixture of wheat straw and cattle wastewater was studied. Four treatments with the composting time of 0d (Tl), 3d (T2), 6d (T3) and 9d (T4) were designed, and then the composted mixture of wheat straw and cattle wastewater (MS) were used for biogas production respectively. The results indicated that much organic matter of MS were decomposed during composting process and TS (total solid) loss rate of Tl, T2 and T3 were 2.63%, 11.46% and 20.00%, respectively. The TS biogas yield of MS was not improved by composting pretreatment and the TS biogas yield of T2, T3 and T4 were 103.01%, 93.96% and 93.68% compared to that of Tl. Taking into account the impact of TS loss of WSCW during composting process, the TS biogas yield of T2, T3 and T4 were 100.30%, 83.19% and 77.59% compared to that of Tl. After 3 days composting pretreatment, the time for the rate of cumulative biogas production to total biogas production up to 80% was 8 days shorter and the peak of daily biogas yield was 2.65mL/d higher than that of control. However, when the composting pretreatment time was too long, the biogas production rate was decreased. The TS and VS (volatile solid) loss rate of MS were decreased with the increasing composting pretreatment time. The above results showed that, composting pretreatment was not a good way for biogas production improvement of MS, but could improve biogas production rate and shorten start-up time and the composting time of 3 days was acceptable.%为深入探讨堆肥预处理对秸秆厌氧发酵产沼气的影响,分别以堆肥0d(T1)、3d(T2)、6d(T3)和9d(T4)的麦秸与奶牛废水混合物(质量比1:2)为原料进行厌氧消化实验.结果表明,堆肥造成麦秸干物质(TS)大量损失,堆肥3,6,9d麦秸TS损失率分别为2.63％、11.46％和20.00％,各处理间差异显著,堆肥后麦秸纤维素结晶程度增强；厌氧发酵后,T1、T2、T3和T4的TS产气量分别为377.50,388.85,354.71353.65mL/g,考虑到堆肥过程中麦秸TS的损失,T2、T3和T4的TS产气量仅为T1的100.30％、83.19％和77.59％;各处理麦秸产气中甲烷含量差异不显著(P=0.3681);堆肥后麦秸产气速率和气峰值均增加,T2、T3累积产气量达到总产气量80％的时间较对照提前了8d和2d,T2产气峰值较对照增加了2.65mL/d,但堆肥9d麦秸产气速率和产气峰值反而降低；厌氧发酵后麦秸TS和挥发性固体损失率均随着堆肥时间的延长而降低.从提高麦秸产沼气量的角度看,堆肥预处理并不合适,但对加快反应器启动,提高麦秸产气速率有一定促进作用,以堆肥3d的效果最好.