Bagwell Christopher E, Rodríguez-Ramos Josué A, Hoyle Sabrina, Phillips Shelby, Day-Lewis Frederick D, Hensel Bruce
Environmental and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, United States.
Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, United States.
Front Microbiol. 2025 May 23;16:1593892. doi: 10.3389/fmicb.2025.1593892. eCollection 2025.
Coal combustion accounts for 40% of the world's electricity and generates more than a billion tons of coal combustion products (CCP) annually, half of which end up in landfills and impoundments. CCP contain mixtures of chemicals that can be mobile in the environment and impact the quality of surface water and potable groundwater. In this investigation, water samples from 14 coal combustion management sites across 4 physiographic regions in the United States, paired with background and down-gradient groundwater samples, were analyzed for water chemistry and microbiology. The objective was to determine if microbiology data alone, or supported by chemistry data, could reliably differentiate source waters and identify sites where CCP is known or expected to be influencing groundwater. Two percent of the total amplicons showed genus level conservation across CCP management sites, regions, and sample types; corresponding to ubiquitous, facultatively aerobic proteobacterial taxa that are generally recognized for the potential to respire using different terminal electron acceptors. Ordination plots did not reveal significant differences ( > 0.05) in 16S rRNA gene amplicon diversity by CCP management site, water sample types, or physiographic regions. Contrastingly, chemistry distinguished sample types by standard water quality metrics (total dissolved solids, Ca:SO ratio), alkali earth metals (K, Na, Li), selenium, boron, and fluoride. A focused evaluation of 16S rRNA gene amplicons for a subset of CCP management sites revealed microbiological features and chemical drivers (F, Ca, temperature) that positively identified the single CCP management site confirmed to have groundwater impacted by CCP leachate. At this site, 9 genera (>0.5% relative abundance) were exclusive to CCP porewater and downgradient groundwater. Inferred metabolisms for these taxa indicates potential for N and S biogeochemical transformations and 1-C metabolism that are consistent with a reducing environment, as evidenced by low ORP and depleted SO . This research contributes to a growing understanding of conditions where these data types, analyses, and interpretation methods could be applied for distinguishing influence from CCP on the surrounding environment, as well as practical limitations.
煤炭燃烧占全球发电量的40%，每年产生超过10亿吨的煤炭燃烧产物（CCP），其中一半最终被填埋和储存。CCP包含多种化学物质的混合物，这些化学物质在环境中具有流动性，会影响地表水和饮用水源地下水的质量。在这项调查中，对美国4个自然地理区域的14个煤炭燃烧管理场地的水样，以及与之配对的背景和下游地下水样进行了水化学和微生物学分析。目的是确定仅微生物学数据，或在化学数据支持下，是否能可靠地区分水源，并识别已知或预计CCP正在影响地下水的场地。在所有CCP管理场地、区域和样品类型中，2%的总扩增子显示出属水平的保守性；这对应于普遍存在的兼性需氧变形菌分类群，这些分类群通常因具有使用不同终端电子受体进行呼吸的潜力而被认可。排序图未显示CCP管理场地、水样类型或自然地理区域在16S rRNA基因扩增子多样性上存在显著差异（>0.05）。相比之下，化学性质通过标准水质指标（总溶解固体、钙：硫比）、碱土金属（钾、钠、锂）、硒、硼和氟化物区分了样品类型。对一部分CCP管理场地的16S rRNA基因扩增子进行的重点评估揭示了微生物特征和化学驱动因素（氟、钙、温度），这些因素明确识别出了一个经确认有受CCP渗滤液影响的地下水的单一CCP管理场地。在这个场地，9个属（相对丰度>0.5%）是CCP孔隙水和下游地下水所特有的。这些分类群的推断代谢表明存在氮和硫生物地球化学转化以及一碳代谢的潜力，这与还原环境一致，低氧化还原电位和贫硫化物证明了这一点。这项研究有助于人们进一步了解在哪些情况下，这些数据类型、分析方法和解释方法可用于区分CCP对周围环境的影响以及实际限制。
