Abstract Coal deposits comprise a huge proportion of carbon sequestered within the Earths crust. Many deposits are anthropogenically altered by mining operations. The changes in local hydrogeology include, first - water removal from the seam to enable excavations, second – restoration of natural water condition by cessation of water pumping. In each of these cases, there is a substantial change in the living conditions of microorganisms and coal sorption capacity towards gases. In the presented study, an attempt was made to connect results depicting structural changes (FT-IR), microbial community composition (NGS) and activity (GC) of four materials representing various stages of coalification upon hydratation. The issue is important as coal transformation often leads to generation of gases with high global warming potentials (CO2 and CH4). In all samples, hydratation led to coal dearomatization, decarboxylation and decompaction. The main gaseous product upon hydratation was carbon dioxide which was linked with both changes in coal sorption capacity upon hydratation and activity of the autochthonic microbiota. CO2 release was higher in lignites than in the hard coals. Within the experimental timeframes of 450 days, methane production was rather marginal. Furthermore, microbial communities composition suggests intrinsic turnover of that gas by the methanotrophic bacteria.

中文翻译：

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硬煤和褐煤的水致分子变化

摘要 煤沉积物在地壳中占据了很大一部分碳。许多矿床被采矿作业人为改变。当地水文地质的变化包括，首先 - 从煤层中取出水以进行挖掘，其次 - 通过停止抽水来恢复自然水条件。在每一种情况下，微生物的生存条件和煤对气体的吸附能力都发生了重大变化。在所提出的研究中，尝试将描述结构变化 (FT-IR)、微生物群落组成 (NGS) 和活性 (GC) 的四种材料的结果联系起来，这些材料代表了水合后煤化的不同阶段。这个问题很重要，因为煤炭转化通常会导致产生具有高全球变暖潜能值的气体（CO2 和 CH4）。在所有样品中，水合导致煤脱芳构化、脱羧和分解。水合时的主要气态产物是二氧化碳，这与水合后煤吸附能力的变化和原生微生物群的活性有关。褐煤中的 CO2 释放量高于硬煤。在 450 天的实验时间范围内，甲烷产量相当有限。此外，微生物群落组成表明甲烷营养细菌对气体的内在周转。褐煤中的 CO2 释放量高于硬煤。在 450 天的实验时间范围内，甲烷产量相当有限。此外，微生物群落组成表明甲烷营养细菌对气体的内在周转。褐煤中的 CO2 释放量高于硬煤。在 450 天的实验时间范围内，甲烷产量相当有限。此外，微生物群落组成表明甲烷营养细菌对气体的内在周转。