搅拌对猪粪半干法发酵产沼气的影响

［目的］研究搅拌对猪粪厌氧发酵产沼气的影响。［方法］采用35℃半干法批量发酵方式，在产气缓慢期和衰退期设置搅拌速率为200r/min的搅拌试验。［结果］45d的厌氧发酵COD去除率达到91.96%，产气率为0.148ml/kg，产气旺盛期日产气量波动较大。产气缓慢期搅拌5min产气速率增加1.04ml/（min·kg），同时使温度升高，pH值下降；与搅拌5、15min相比，产气衰退期搅拌10min最有利于发酵。［结论］持续5min间隔50min为1周期的搅拌方法即可使该试验产气及时排出。

Effects of Stirring on Semi-dry Anaerobic Digestion of Pig Dung for Biogas Production

[Objective] The research aimed to study the effects of stirring on semi-dry anaerobic digestion of pig dung for biogas production. [Method] Stirring at 200 r/min was set during slow and recessionary phases in semi-dry batch performed at 35 ℃, to research its experimental effects in pig dung anaerobic digestion for biogas production. [Result] The results showed that COD degradative rate was 91.96 % after anaerobic digestion 45 d and biogas production rate was 0.148 ml/kg, but daily biogas yield change was large in fast-production phase. Gas production speed enhanced 1.04 ml/(min·kg),temperature rose, and pH value descended by stirring 5 min in slow-production phase. Stirring 10 min phase was better than 5, 15 min for anaerobic digestion in recessionary. [Conclusion] The stirring manner of continuing 5 min and pausing 50 min in a cycle can make biogas production emit in time.