稻草与畜禽粪便混合物厌氧消化快速启动研究

Fast Start-up of Anaerobic Digestion of Rice Straw and Livestock Manure

大型沼气工程的启动需要有大量的外源接种物,这使得启动成本增高。为了实现沼气工程低成本快速启动,文章以稻草与粪便(牛粪、猪粪)按0∶1,1∶2,1∶1,2∶1和4∶1(VS比)混合后,在不外加接种物的情况下直接启动。结果表明:除稻草与猪粪4∶1混合外,不同比例的稻草与粪便混合后均能启动成功。添加不同比例牛粪的启动效果优于添加猪粪的启动效果,同时在不外加接种物的情况下,少量稻草与粪便混合的启动效果优于单独粪便的启动效果。稻草与牛粪和猪粪的混合比例均为1∶2时效果最佳,单位VS产气量分别为258 mL·g^-1和187 mL·g^-1,T 80(累积产气量达到总产气量80%时所需的时间)分别为29 d和39 d,氨氮分别为434 mg·L^-1和728 mg·L^-1,碱度为5250 mg·L^-1和5300 mg·L^-1。两种混合方式都可以快速启动且厌氧系统性能稳定,该研究结果可为大型沼气工程启动提供技术支持并可大大节省启动成本。

Starting-up of a large-scale biogas projects requires a huge amount of exogenous inoculums,which greatly increases the starting-up cost of biogas projects.In order to achieve low-cost and fast starting-up of biogas project,this paper mixed rice straw with cow manure or pig manure with mixing ratio of 0∶1,1∶2,1∶1,2∶1,and 4∶1(VS ratio)without inoculums.The results showed that,except the 4∶1 mixture,different proportions of rice straw and manure could be successfully started.Adding of cow manure was better than adding pig manure.Meanwhile,in the case of no inoculums,the starting-up with a small amount of straw was better than that of the sole manure.The best straw to manure mixing ratio was 1∶2 for both cow manure and pig manure,there biogas production per unit VS was 258 mL·g^-1 and 187 mL·g^-1,respectively,and the T80(the time required when the cumulative gas production reaches 80%of the total gas production)were 29 d and 39 d,respectively.During the process,the ammonia nitrogen were 434 mg·L^-1 and 728 mg·L^-1,and alkalinity were 5250 mg·L^-1 and 5300 mg·L^-1 respectively,which were believed to be under optimum condition.The mixing ratio of 1∶2 was suitable for both mixture with cow or pig manure for quick start-up and digestion performance.