不同预处理方式对市政污泥/餐厨垃圾混合厌氧消化产甲烷的影响

Methanogenic characteristics of anaerobic co-digestion using municipal sludge and food waste under different pretreatment

考察了不同的预处理方式对餐厨垃圾与市政污泥混合厌氧消化产甲烷的影响。结果表明:对市政污泥进行热碱预处理效果最优,与空白组相比,热碱处理组累计单位质量的挥发性固体(VS)的甲烷产量达到了255.00 L,提高了13.03%,溶解性化学需氧量(SCOD)的降解率提高了27.05%,总固体(TS)的降解率提高了16.65%,VS的降解率提高了9.08%。在厌氧消化过程中,利用碳水化合物及蛋白质的热袍菌门(Thermotogae)的比例在所有处理中都有所上升;与产生短链脂肪酸有关的Erysipelotrichaceae菌属在预处理组中的丰度显著高于空白组,热碱处理组中Erysipelotrichaceae在末期的丰度最高,为19.21%;Petrimonas在厌氧消化体系中的作用为产氢产乙酸菌,热碱处理组的Petrimonas的丰度在产气高峰时最高,为6.84%。不同处理系统起主要产甲烷作用的古菌属为Methanosarcina,在产气高峰期热碱预处理组中Methanosarcina的丰度最高。预处理能够破环市政污泥的细胞结构,提高污泥的可生物利用性,提高混合厌氧消化产甲烷的效率。

Different pretreatment methods for biomethane production by anaerobic co-digestion of municipal sludge and food waste were studied at the mesophilic temperature(38±0.5 ℃).The optimal cumulative methane production reached 255.00 L/kg VS in the heat alkali pretreatment system, can increased by 13.03% than that in the blank group. Meanwhile, SCOD degradation rate, TS degradation rate, and VS degradation rate in the heat alkali pretreatment system were also increased by 27.05%,16.65%,and 9.08% than the blank group, respectively.In all groups, the proportion of Thermotogae that can utilize carbohydrate and protein in bacterial flora was increased.The proportion of Erysipelotrichaceae that had a strong positive correlation with the production of volatile fatty acids was increased in all the pretreatment groups, and the abundance of Erysipelotrichaceae in the heat alkali pretreatment group was 19.21% and higher than that in the other groups.Petrimonas was hydrogen and acetic acid producing bacterium in the anaeroic digestion system, and the abundance of Petrimonas in the heat alkali treatment group was the largest, 6.84% at the peak of biogas production.Methanosarcina is still the main methanogenic archaea, and Methanosarcina had the highest abundance in the heat alkali treatment group compared with other groups at the peak stage of biogas production.In conclusion, the pretreatments enhanced the municipal sludge solubilization, increased the likelihood of the degradation of the sludge, and then improved the biomethane production efficiency in the anaerobic co-digestion of municipal sludge and food waste system.