Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Instrumental Analysis Center, School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China.
College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang Province, 310058, China.
Environ Pollut. 2022 Aug 1;306:119363. doi: 10.1016/j.envpol.2022.119363. Epub 2022 Apr 27.
Sulfidized nanoscale zero-valent iron (S-nZVI) is a promising material for in situ soil remediation. However, its transformation (i.e., aging) and effects on the microbial community in soil ecosystems are largely unknown. In this study, S-nZVI having low (S-nZVI (L)) and high sulfur-doping (S-nZVI (H)) were incubated in soil microcosms and bare nZVI was used as a control. Their aged products were characterized using microspectroscopic analyses and the changes in the corresponding soil microbial community were determined using high-throughput sequencing analyses. The results indicate that severe corrosion of both bare and S-nZVI occurred over 56 days of aging with significant morphological and mineral changes. Magnetite, lepidocrocite, and goethite were detected as the main aged products. In addition, sulfate ions, pyrite, and iron polysulfide were formed in the aged products of S-nZVI. Cr(VI) removal test results indicated that S-nZVI(L) achieved the best results after aging, likely because of the optimal FeS arrangement on its nanoparticle surfaces. The presence of nZVI and S-nZVI increased the abundance of some magnetotactic microorganisms and altered bacterial and fungal community structures and compositions. Moreover, the addition of S-nZVI enriched some bacterial and fungal genera related to sulfur cycling because of the presence of sulfide-bearing material. The findings reveal the transformation of S-nZVI during aging and its effects on microbial communities in soil ecosystems, thereby helping to the evaluation of S-nZVI application in soil remediation.
硫化纳米零价铁（S-nZVI）是一种很有前途的原位土壤修复材料。然而，其在土壤生态系统中的转化（即老化）及其对微生物群落的影响在很大程度上尚不清楚。在本研究中，将低硫掺杂纳米零价铁（S-nZVI (L)）和高硫掺杂纳米零价铁（S-nZVI (H)）两种 S-nZVI 分别在土壤微宇宙中进行培养，并用 bare nZVI 作为对照。使用微光谱分析对它们的老化产物进行了表征，并使用高通量测序分析确定了相应土壤微生物群落的变化。结果表明，在 56 天的老化过程中，bare 和 S-nZVI 都发生了严重的腐蚀，其形态和矿物发生了显著变化。检测到磁铁矿、纤铁矿和针铁矿是主要的老化产物。此外，在 S-nZVI 的老化产物中形成了硫酸盐离子、黄铁矿和铁多硫化物。Cr(VI)去除测试结果表明，S-nZVI(L)在老化后效果最佳，可能是因为其纳米颗粒表面的 FeS 排列最佳。nZVI 和 S-nZVI 的存在增加了一些趋磁微生物的丰度，并改变了细菌和真菌群落的结构和组成。此外，由于含有含硫物质，S-nZVI 的添加丰富了一些与硫循环有关的细菌和真菌属。研究结果揭示了 S-nZVI 在老化过程中的转化及其对土壤生态系统中微生物群落的影响，从而有助于评估 S-nZVI 在土壤修复中的应用。
