CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Chinese Academy of Sciences, Beijing 100190, China.
Int J Environ Res Public Health. 2020 Apr 15;17(8):2715. doi: 10.3390/ijerph17082715.
Mining waste rocks containing sulfide minerals naturally provide the habitat for iron- and sulfur-oxidizing microbes, and they accelerate the generation of acid mine drainage (AMD) by promoting the oxidation of sulfide minerals. Sulfate-reducing bacteria (SRB) are sometimes employed to treat the AMD solution by microbial-induced metal sulfide precipitation. It was attempted for the first time to grow SRB directly in the pyritic heap bioleaching residue to compete with the local iron- and sulfur-oxidizing microbes. The acidic SRB and iron-reducing microbes were cultured at pH 2.0 and 3.0. After it was applied to the acidic heap bioleaching residue, it showed that the elevated pH and the organic matter was important for them to compete with the local bioleaching acidophiles. The incubation with the addition of organic matter promoted the growth of SRB and iron-reducing microbes to inhibit the iron- and sulfur-oxidizing microbes, especially organic matter together with some lime. Under the growth of the SRB and iron-reducing microbes, pH increased from acidic to nearly neutral, the Eh also decreased, and the metal, precipitated together with the microbial-generated sulfide, resulted in very low Cu in the residue pore solution. These results prove the inhibition of acid mine drainage directly in situ of the pyritic waste rocks by the promotion of the growth of SRB and iron-reducing microbes to compete with local iron and sulfur-oxidizing microbes, which can be used for the source control of AMD from the sulfidic waste rocks and the final remediation.
含硫化物矿物的采矿废石自然为铁和硫氧化微生物提供了栖息地，它们通过促进硫化物矿物的氧化加速了酸性矿山排水（AMD）的产生。硫酸盐还原菌（SRB）有时被用于通过微生物诱导的金属硫化物沉淀来处理 AMD 溶液。首次尝试直接在含硫堆浸残渣中培养 SRB，以与当地的铁和硫氧化微生物竞争。在 pH 值为 2.0 和 3.0 的条件下培养酸性 SRB 和铁还原微生物。将其应用于酸性堆浸残渣后，结果表明，升高的 pH 值和有机物对它们与当地浸矿嗜酸微生物竞争非常重要。添加有机物的孵育促进了 SRB 和铁还原微生物的生长，抑制了铁和硫氧化微生物的生长，特别是有机物与一些石灰一起。在 SRB 和铁还原微生物的生长下，pH 值从酸性升高到近中性，Eh 值也降低，金属与微生物产生的硫化物一起沉淀，导致残渣孔隙溶液中的 Cu 非常低。这些结果证明，通过促进 SRB 和铁还原微生物的生长来与当地的铁和硫氧化微生物竞争，可以直接抑制含硫废石中的酸性矿山排水，从而可以控制硫化物废石中的 AMD 源，并最终进行修复。
