Vásquez Yaneth, Galvis José A, Pazos Jhon, Vera Camila, Herrera Oscar
Faculty of Engineering and Basic Sciences, Department of Natural Sciences, Universidad Central, Bogotá, Colombia.
Convergence Science and Technology Cluster, Universidad Central, Bogotá, Colombia.
Environ Technol. 2022 May;43(13):1988-2001. doi: 10.1080/09593330.2020.1864024. Epub 2020 Dec 30.
Acid mine drainage (AMD) is the major effluent generated from metal and coal mines, causing serious ecological risks and degradation of aquatic habitats and surrounding soil quality. Biochemical passive reactors (BPRs) are an option for improving AMD affected water. This study investigates the effect of the size and concentration of zerovalent iron nanoparticles (nZVI) on the efficiency of batch BPRs during AMD remediation. Atomic force microscopy (AFM) and transmission electron microscopy (TEM) were also used as complementary techniques for the investigation of the changes in microbial cells and nZVI properties after the AMD remediation. The results from the batch experiment showed that the concentration of nZVI increases the pH and decreases ORP during AMD treatment, thus favouring the removal of metals. The results also suggest that metal sulfide precipitation occurred in all the batch with reactive mixture but was greater in reactors amended with nZVI of larger size. This study revealed that the presence of nZVI in the BPR leads to metal removal as well as the inhibition of sulfate-reducing bacteria (SRB) activity. Microscopy study indicated that the addition of nZVI creates a morphological change on certain microorganisms in which the cellular membrane was fully covered with nZVI, inducing cell lysis process. These results show that nZVI is a promising reactive material for the treatment of AMD in BPR systems.
酸性矿山排水（AMD）是金属矿和煤矿产生的主要废水，会造成严重的生态风险，并导致水生生境退化和周边土壤质量下降。生化被动反应器（BPRs）是改善受AMD影响水体的一种选择。本研究调查了零价铁纳米颗粒（nZVI）的尺寸和浓度对AMD修复过程中批次BPRs效率的影响。原子力显微镜（AFM）和透射电子显微镜（TEM）也被用作补充技术，用于研究AMD修复后微生物细胞和nZVI性质的变化。批次实验结果表明，在AMD处理过程中，nZVI的浓度会提高pH值并降低氧化还原电位（ORP），从而有利于金属的去除。结果还表明，在所有含有反应性混合物的批次中都发生了金属硫化物沉淀，但在添加较大尺寸nZVI的反应器中沉淀量更大。本研究表明，BPR中nZVI的存在导致了金属的去除以及对硫酸盐还原菌（SRB）活性的抑制。显微镜研究表明，添加nZVI会使某些微生物发生形态变化，其中细胞膜被nZVI完全覆盖，从而引发细胞裂解过程。这些结果表明，nZVI是BPR系统中处理AMD的一种有前景的活性材料。
