Liu Hao, Yin Xuefeng, Zhang Na, Huang Minjie, Liang Dongxu, Wang Hao
State Key Laboratory of Environmental Pollution Control and Waste Recycling in Inner Mongolia Autonomous Region, Department of Ecology and Environment, Inner Mongolia University, Hohhot, Inner Mongolia 010021, China.
School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China.
ACS Omega. 2025 Aug 27;10(35):40146-40161. doi: 10.1021/acsomega.5c05027. eCollection 2025 Sep 9.
Coalbed methane enhancement technologies are critical for clean and efficient utilization of low-rank coal resources. However, current biological conversion efficiencies remain limited because of low electron transfer rates and insufficient activity of methanogenic bacteria. In this study, a synergistic enhancement strategy combining pyrite addition and electrical stimulation was proposed to improve methane production from brown coal during anaerobic fermentation by promoting microbial electron transport and metabolic activity. Gradient experiments were conducted under varying pyrite dosages (0-32%) and voltage conditions (0-6 V), coupled with 16S rRNA high-throughput sequencing to systematically analyze gas production, key physicochemical parameters, and microbial community shifts. The results indicated that the combined treatment (16% pyrite + 3 V) increased the cumulative methane yield to 4220 mL over a 30 day fermentation period, representing a 767% increase compared with the untreated control. Concurrently, the relative abundance of increased from 1.42% to 9.13%. Pyrite functioned as an Fe/S electron shuttle to facilitate direct electron transfer, whereas electrical stimulation enhanced H production and jointly optimized the hydrogenotrophic methanogenesis pathway. A threshold effect was also identified, whereby excessive pyrite or high voltage induced Fe/S toxicity and water electrolysis side reactions, compromising system stability. This synergistic strategy achieved a 7-fold increase in methane yield without the addition of conventional chemical additives such as nutrients, enzymes, or synthetic mediators, highlighting its potential for application in the biological intensification of low-rank coal exploitation.
煤层气强化技术对于低阶煤资源的清洁高效利用至关重要。然而，由于电子传递速率低和产甲烷菌活性不足，目前的生物转化效率仍然有限。在本研究中，提出了一种结合添加黄铁矿和电刺激的协同强化策略，通过促进微生物电子传递和代谢活性来提高褐煤厌氧发酵过程中的甲烷产量。在不同黄铁矿剂量（0 - 32%）和电压条件（0 - 6 V）下进行梯度实验，并结合16S rRNA高通量测序，系统分析产气情况、关键理化参数和微生物群落变化。结果表明，联合处理（16%黄铁矿 + 3 V）在30天的发酵期内将累计甲烷产量提高到4220 mL，与未处理的对照相比增加了767%。同时， 的相对丰度从1.42%增加到9.13%。黄铁矿作为Fe/S电子穿梭体促进直接电子传递，而电刺激增强了氢气产生并共同优化了氢营养型甲烷生成途径。还发现了一种阈值效应，即过量的黄铁矿或高电压会诱导Fe/S毒性和水电解副反应，损害系统稳定性。这种协同策略在不添加营养物质、酶或合成介质等传统化学添加剂的情况下使甲烷产量提高了7倍，突出了其在低阶煤开采生物强化中的应用潜力。
