Gao Kun, Hu Yue, Guo Chuling, Ke Changdong, Lu Guining, Dang Zhi
School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou 510006, PR China.
School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou 510006, PR China.
J Hazard Mater. 2021 Jan 15;402:123717. doi: 10.1016/j.jhazmat.2020.123717. Epub 2020 Aug 19.
Microbial sulfidization of arsenic (As)-bearing jarosite involves complex processes and is yet to be fully elucidated. Here, we investigated the behavior of As during reductive dissolution of As(V)-bearing jarosite by a pure sulfate reducing bacterium with or without dissolved SO amendment. Changes of aqueous chemistry, mineralogical characteristics, and As speciation were examined in batch experiments. The results indicated that jarosite was mostly replaced by mackinawite in the system with added SO. In the medium without additional SO, mackinawite, vivianite, pyrite, and magnetite formed as secondary Fe minerals, though 24.55 % of total Fe was in form of an aqueous Fe phase. The produced Fe in turn catalyzed the transformation of jarosite. At the end of the incubation, 41.99 % and 48.10 % of As in the solid phase got released into the aqueous phase in the systems with and without added SO, respectively. The addition of dissolved SO mitigated the mobilization of As into the aqueous phase. In addition, all As on the solid surface was reduced to As during the microbial sulfidization of As-bearing jarosite. These findings are important for a better understanding of geochemical cycling of elements As, S, and Fe in acid mine drainage and acid sulfate soil environments.
含砷黄钾铁矾的微生物硫化过程复杂，尚未完全阐明。在此，我们研究了在有或没有溶解态SO添加的情况下，纯硫酸盐还原菌对含As(V)黄钾铁矾进行还原溶解时As的行为。在批次实验中检测了水化学变化、矿物学特征和As的形态。结果表明，在添加了SO的体系中，黄钾铁矾大部分被马基诺矿取代。在没有额外SO的培养基中，马基诺矿、蓝铁矿、黄铁矿和磁铁矿作为次生Fe矿物形成，尽管总Fe的24.55%以水溶态Fe相的形式存在。生成的Fe反过来催化了黄钾铁矾的转化。培养结束时，在添加和未添加SO的体系中，固相中的As分别有41.99%和48.10%释放到水相中。溶解态SO的添加减轻了As向水相中的迁移。此外，在含砷黄钾铁矾的微生物硫化过程中，固体表面的所有As都被还原为As。这些发现对于更好地理解酸性矿山排水和酸性硫酸盐土壤环境中As、S和Fe元素的地球化学循环具有重要意义。
