颗粒活性炭强化餐厨垃圾中食用油厌氧消化产甲烷

Methanogenesis of Edible Oil from Kitchen Waste Enhanced by Granular Activated Carbon

通过投加颗粒活性炭(GAC)强化直接种间电子传递(DIET),进而提升餐厨垃圾中常见食用油的厌氧消化产甲烷效能,并分析投加GAC对微生物群落结构的影响。研究发现,与未投加GAC的对照组相比较,投加GAC的实验组可以高效稳定地进行厌氧消化产甲烷。在菜籽油厌氧消化过程中,对照组的乙酸浓度在第7天达到最大值(7 mmol/L),之后基本保持不变。而在投加GAC的实验组中,乙酸浓度在第7天达到最大值(3.9 mmol/L),之后逐渐降低,到第13天基本为0。与此同时,实验组的最大甲烷产量约为对照组的3.5倍。因而,投加GAC促进了乙酸的降解和甲烷的转化。对微生物群落结构进行分析发现,投加GAC的实验组中富集了大量可能具有胞外电子传递功能的细菌(Syntrophomonas和Geobacter),以及可以参与DIET的产甲烷菌(Methanosarcina),表明投加GAC可以有效富集以上三种微生物,并通过GAC作为电子载体促进菜籽油厌氧反应体系中DIET的形成,进而促进菜籽油的降解,提高甲烷产量。

Direct interspecies electron transfer(DIET)was enhanced by adding granular activated carbon(GAC),so as to improve the anaerobic methanogenic efficiency of common edible oil from kitchen waste.In addition,the effect of GAC on microbial community composition was analyzed.Compared with the control group without GAC,the experimental group with GAC efficiently and stably produced methane through anaerobic digestion.During the anaerobic digestion of rapeseed oil,the acetic acid concentration in the control group reached the maximum value(7 mmol/L)on day 7 and remained basically unchanged thereafter.However,in the experimental group,the acetic acid concentration reached the maximum value(3.9 mmol/L)on day 7,and then gradually decreased to zero on day 13.Meanwhile,the maximum methane production in the experimental group was approximately 3.5 times that in the control group.Therefore,the addition of GAC promoted the degradation of acetic acid and the conversion of methane.Analysis of microbial community composition showed that a large number of bacteria(Syntrophomonas and Geobacter)that might have extracellular electron transfer function and a methanogen(Methanosarcina)that participated in DIET were enriched in the experimental group.The results suggested that the addition of GAC could enrich these three groups of microbes,and promote the formation of DIET in the rapeseed oil anaerobic digestion system through GAC as an electron carrier,thus promoting the degradation of rapeseed oil and improving the methane production.