添加铁氧化物和活性炭对玉米秸秆两相厌氧消化性能和微生物学特性影响研究

为了提高玉米秸秆厌氧消化性能，将铁氧化物（Fe₂O₃，Fe₃O₄）和活性炭分别添加到玉米秸秆两相厌氧消化系统中的酸化相和甲烷相进行试验。结果表明，在酸化相和甲烷相中分别添加Fe₃O₄粉末和活性炭粉末（PAC）的试验组效果最佳。Fe₃O₄粉末添加到酸化相后，挥发性脂肪酸（volatile fatty acids，VFAs）与乙醇的总含量比对照组中两者的总含量提高了25.4%。酸化结束后加入活性炭粉末继续进行甲烷化试验，玉米秸秆累积产甲烷量达到7 965 mL，比对照组提高了27.8%。与对照组相比，添加Fe₃O₄粉末和活性炭粉末试验组的t₈₀（累积产甲烷量达到总甲烷产量的80%所用的时间）缩短了8 d，电导率提高了33.3%。从微生物群落角度分析，在Fe₃O₄+PAC试验组中，细菌优势菌属为Clostridium_sensu_stricto_1，古菌优势菌属为Methanobacterium，可以提高H₂利用率并且促进厌氧过程中的直接种间电子传递（direct interspecies electron transfer，DIET）。因此，Fe₃O₄粉末和活性炭粉末的添加可以有效提高玉米秸秆厌氧消化产甲烷潜力。

Effects of adding iron oxide and activated carbon on the two-phase anaerobic digestibility and microbiological characteristics of corn stover

In order to improve the anaerobic digestibility of corn stover, iron oxides (Fe₂O₃, Fe₃O₄) and activated carbon were respectively added during the acidification phase and methanation phase of a corn stover two-phase anaerobic digestion system. The results showed that the optimal anaerobic digestion performance was achieved with Fe₃O₄ powder and powdered activated carbon (PAC). When Fe₃O₄ powder was added during the acidification phase, the combined content of volatile fatty acids (VFAs) and ethanol increased by 25.4% compared with the control group. After the acidification was complete, PAC was added to continue methanation. The methane production of the Fe₃O₄+PAC group reached 7 965 mL, which was 27.8% higher than that of the control group. Compared to the control group, t₈₀ (the time required for the cumulative methane production to reach 80% of the total methane production) of the Fe₃O₄+PAC group was reduced by eight days, and the conductivity of the Fe₃O₄+PAC group increased by 33.3%. According to the analysis of the microbial community, in the Fe₃O₄ + PAC group, the dominant bacterial genus was Clostridium_sensu_stricto_1, and the dominant archaea genus was Methanobacterium, which can improve the utilization rate of H₂ and promote direct interspecies electron transfer (DIET) in the anaerobic process. Therefore, the addition of Fe₃O₄ powder and PAC can effectively increase the methane production potential of corn stover during the process of anaerobic digestion.