餐厨垃圾和家庭厨余垃圾共消化产沼的规律研究

Study on the Law of Co-digestion of Restaurant Food Waste and Household Kitchen Waste to Produce Biogas

试验设计5个组别,分别探究5种餐厨垃圾和家庭厨余垃圾混合比条件下厌氧共消化系统的产沼规律及微生物群落特征。其中,试验组1、试验组2、试验组3、试验组4和试验组5的餐厨垃圾和家庭厨余垃圾混合比分别为10∶0、7∶3、5∶5、3∶7和0∶10。结果表明,不同混合比条件下,累积沼气产量从高到低的排序依次为试验组3>试验组4>试验组2>试验组5>试验组1,混合比为5∶5时,沼气产量最高。相比Cone模型,改进的Gompertz模型更适合拟合餐厨垃圾和家庭厨余垃圾共消化产沼动力学规律。餐厨垃圾和家庭厨余垃圾共消化的协同效应主要发生在厌氧消化的前10 d,混合比为5∶5时协同作用最强。餐厨垃圾和家庭厨余垃圾共消化可促进化学需氧量(Chemical Oxygen Demand,COD)去除率的提高,但对碳水化合物和蛋白质的降解率影响较小。当混合比为5∶5时,互营单胞菌属的相对丰度较高,氢营养型产甲烷菌相对丰度最高,表明此时水解产酸菌和产甲烷菌更平衡,更有利于沼气的产生。

The experiment designs 5 groups to explore the biogas production law and microbial community characteristics of anaerobic co-digestion systems under 5 different mixing ratios of restaurant food waste and household kitchen waste.Among them,the mixing ratios of restaurant food waste and household kitchen waste in experimental group 1,experimental group 2,experimental group 3,experimental group 4,and experimental group 5 are 10∶0,7∶3,5∶5,3∶7,and 0∶10,respectively.The results show that under different mixing ratios,the order of cumulative biogas production from high to low is experimental group 3>experimental group 4>experimental group 2>experimental group 5>experimental group 1,when the mixing ratio is 5∶5,the biogas production is the highest.Compared to the Cone model,the improved Gompertz model is more suitable for fitting the kinetics of co-digestion and biogas production of restaurant food waste and household kitchen waste.The synergistic effect of co-digestion of restaurant food waste and household kitchen waste mainly occurs in the first 10 d of anaerobic digestion,and the synergistic effect is strongest when the mixing ratio is 5∶5.Codigestion of restaurant food waste and household kitchen waste can promote the improvement of Chemical Oxygen Demand(COD)removal rate,but has little effect on the degradation rate of carbohydrates and proteins.When the mixing ratio is 5∶5,the relative abundance of Syntrophomonas is higher,and the relative abundance of Methanococcus is the highest,indicating that the hydrolysis acid producing bacteria and methane producing bacteria are more balanced and more conducive to biogas production.