生物强化促进餐厨垃圾高温厌氧消化产甲烷性能的研究

Study on Bioaugmentation to Promote Methanogenic Performance of Thermophilic Anaerobic Digestion of Food Waste

为探究水原脲芽孢杆菌Ureibacillus suwonensis E11的添加量对餐厨垃圾高温(55℃)厌氧消化产甲烷性能的影响,优化生物强化的实验条件,本研究采用5 L连续搅拌厌氧反应器,以餐厨垃圾为底物,以长期驯化的高温厌氧污泥为接种物,通过改变微生物添加量(0、5%、10%、15%、20%),对比高温厌氧消化的产甲烷性能,评价强化效果,确定最佳添加剂量,并结合宏基因组数据揭示生物强化的作用机制。结果表明:与未添加功能微生物的对照组相比,各生物强化组产甲烷量均有明显提高。最佳的功能微生物添加量为15%,在此条件下,生物强化组(575.14 mL/g)比对照组(452.86 mL/g)的累积甲烷产量(以VS计)提高27.00%。生物强化可以在一定程度上提高乙酸的利用效率。微生物群落结构分析显示生物强化通过提高几种重要水解细菌以及嗜氢产甲烷菌Methanoculleus的相对丰度,来促进餐厨垃圾高温厌氧消化产甲烷。

In order to explore the effects of adding Ureibacillus suwonensis E11 on the performance of methane production during thermophilic(55℃)anaerobic digestion of food waste,and optimize the experimental conditions for bioaugmentation.A 5 L continuous stirring anaerobic reactor was used in this study with kitchen waste as substrate long-term acclimated high-temperature anaerobic sludge as inoculum.By changing the microbial addition amount(0,5%,10%,15%,20%),the methanogenic performance of high-temperature anaerobic digestion was compared,the enhancement effect was evaluated,the optimal addition dose was determined,and the mechanism of bioenhancement was revealed by combining metagenomic data.The results showed that compared to the control group without the addition of functional microorganisms,all bioaugmentation groups exhibited a significant increase in methane production.The optimal addition rate of functional microorganisms was 15%,and under this condition,the cumulative methane production(measured as VS)in the bioaugmentation group(575.14 mL/g)was 27.00%higher than that in the control group(452.86 mL/g).Bioaugmentation could improve the utilization efficiency of acetic acid to a certain extent.Analysis of the microbial community structure revealed that bioaugmentation promoted the methane production during thermophilic anaerobic digestion of food waste by increasing the relative abundance of several key hydrolytic bacteria and the hydrogenotrophic methanogen Methanoculleus.