Department of Biology, The University of Akron, Akron, OH, USA; Integrated Bioscience Program, The University of Akron, Akron, OH, USA.
Department of Geosciences, The University of Akron, Akron, OH, USA.
Chemosphere. 2020 Jun;249:126117. doi: 10.1016/j.chemosphere.2020.126117. Epub 2020 Feb 10.
Coal mine derived acid mine drainage (AMD) is formed when oxygenated water infiltrates mine voids and oxidizes FeS phases, generating acidic fluid rich in heavy metals, polluting thousands of miles of streams. Existing remediation options are cost-prohibitive and difficult to sustain. In some cases, AMD flows over previously pristine soil in thin sheets over terrestrial surface, enhancing AMD aeration and Fe(II) oxidizing activities, leading to oxidative Fe(II) precipitation from AMD, without any human intervention. Since robust Fe(II) biooxidation occurs in the mixture of intruding AMD and pristine soil, understanding the effects of chemically variant AMD can be exploited for effective Fe(II) removal. We hypothesized that chemistry and microbiology of AMD intruding pristine soil on surface would influence the development of Fe(II) oxidizing capabilities. Therefore, to investigate the response of pristine soil to the addition of AMD varying in chemical and microbial characteristics, we mixed soil with a near-neutral and moderately acidic AMD, in separate incubations. Incubations with near-neutral AMD developed microbial Fe(II) oxidation activities after 10 days. However, Fe(II) oxidation in moderately acidic AMD incubations was mostly abiotic. 16S rRNA gene sequences and metabolic functional prediction (Tax4Fun) analysis of near-neutral AMD and soil mixture indicated development of taxonomically different communities capable of activities similar to microorganisms in a mine void. In conclusion, results indicate that AMD chemistry and microbiology affects development of Fe(II) biooxidation. Therefore, understanding of the effect of AMD chemistry on the development of FeOB activities in soil can be exploited to design site-specific and sustainable solutions.
煤矿酸性矿山排水（AMD）是当含氧水渗透到矿山空洞并氧化 FeS 相时形成的，产生富含重金属的酸性流体，污染数千英里的溪流。现有的修复方案成本过高，难以维持。在某些情况下，AMD 以薄层状流过先前原始的土壤，覆盖陆地表面，增强 AMD 的曝气和 Fe(II)氧化活性，导致 AMD 中的氧化 Fe(II)沉淀，而无需任何人为干预。由于侵入 AMD 和原始土壤混合物中存在强烈的 Fe(II)生物氧化作用，因此可以利用 AMD 的化学变异性来有效地去除 Fe(II)。我们假设侵入原始土壤的 AMD 的化学性质和微生物学性质会影响 Fe(II)氧化能力的发展。因此，为了研究原始土壤对添加具有不同化学和微生物特征的 AMD 的反应，我们将土壤与近中性和中度酸性 AMD 混合，分别进行培养。近中性 AMD 培养物在 10 天后发展出微生物 Fe(II)氧化活性。然而，中度酸性 AMD 培养物中的 Fe(II)氧化主要是无生命的。近中性 AMD 和土壤混合物的 16S rRNA 基因序列和代谢功能预测（Tax4Fun）分析表明，发展出具有类似矿山空洞中微生物相似活动能力的分类上不同的群落。总之，结果表明 AMD 的化学性质和微生物学性质会影响 Fe(II)生物氧化的发展。因此，了解 AMD 化学性质对土壤中 FeOB 活性发展的影响，可以用来设计特定场地和可持续的解决方案。
