共接种瘤胃微生物和厌氧污泥的水稻秸秆中试厌氧消化系统性能评估

Performance evaluation on a pilot-scale anaerobic digestion system of rice straw with co-inoculating ruminal microbiota and anaerobic sludge

针对富含木质纤维素底物利用效率低的问题,通过在中试厌氧消化系统中共接种瘤胃微生物和厌氧污泥来改善水稻秸秆中木质纤维素的水解,采用逐步提升底物有机负荷(OLR)的方式,评估了接种后水稻秸秆的厌氧消化效率。结果表明,在反应体系底物有机负荷达到4.26 g·(L·d)-1(以VS计)时,系统表现出最佳的厌氧消化性能,此时沼气产率为528 mL·g-1 (以VS计),甲烷产率为287 mL·g-1,容积沼气生产强度达到2.20 L·(L·d)-1。在反应器有机负荷从1.05 g·(L·d)-1提升到4.26 g·(L·d)-1的运行过程中,系统的纤维素降解率稳定在(71±2)%,半纤维素降解率稳定在(92±4)%,木质素降解率稳定在(15±3)%。这种稳定性表明反应器的连续运行成功地形成了高效的木质纤维素降解体系,结果可为实际规模化应用提供参考。

In order to overcome the low bioavailability of lignocellulosic biomass,the hydrolysis of rice straw was enhanced by co-inoculating ruminal microbiota and anaerobic sludge in a pilot-scale anaerobic reactor,and the digestion efficiency was evaluated by gradually increasing organic load rate(OLR).The optimal fermentation performance was obtained at the OLR of 4.26 g·(L·d)-1(calculated in VS),where the biogas yield,methane yield and volumetric biogas productivity reached 528 mL·g-1(calculated in VS),287 mL·g-1 and2.20 L·(L·d)-1,respectively.With the increase of OLR from 1.05 g·(L·d)-1 to 4.26 g·(L·d)-1,the degradation efficiencies of cellulose,hemicellulose and lignin was maintained at(71±2)%,(92±4)%and(15±3)%,respectively.The operational stability indicated that a highly efficient lignocellulose degradation system was successfully established by the continuous reactor operation,providing a theoretical basis for the practical scaleup application.