The role of natural Fe(II)-bearing minerals in chemoautotrophic chromium (VI) bio-reduction in groundwater

JOURNAL OF HAZARDOUS MATERIALS

卷:389

Article

Lu, Jianping¹  Zhang, Baogang¹  He, Chao¹  Borthwick, Alistair G. L.^2,3 

[1] China Univ Geosci Beijing, Sch Water Resources & Environm, MOE Key Lab Groundwater Circulat & Environm Evolu, Beijing 100083, Peoples R China

[2] St Edmund Hall,Queens Lane, Oxford OX1 4AR, England

[3] Univ Edinburgh, Sch Engn, Kings Bldg, Edinburgh EH9 3JL, Midlothian, Scotland

关键词: Chromium (VI);    Bio-reduction;    Fe(II)-bearing minerals;    Mackinawite;   

DOI  :  10.1016/j.jhazmat.2019.121911

来源: Elsevier

【 摘 要 】

To date, comparatively little is known about the role of natural Fe(II)-bearing minerals in bioremediation of chromium (VI) contaminated aquifers subject to chemoautotrophic conditions. This work employed four kinds of Fe(II)-bearing minerals (pyrite, mackinawite, wustite, and magnetite) as inorganic electron donors to support Cr (VI) bio-reduction. In batch experiments, mackinawite (FeS) performed best, with Cr(VI) removal efficiency of 98.1 +/- 1.21 % in 96 h. Continuous column experiments lasting 180 d implied that groundwater chemistry and hydrodynamics influenced the Cr(VI) removal process. A breakthrough study suggested that biotic and abiotic contributions to Cr(VI) reduction were 76.0 +/- 1.12 % and 24.1 +/- 1.43 %, respectively. Cr(VI) was reduced to insoluble Cr(III), whereas Fe(II) and S(-II) in mackinawite were finally oxidized to Fe(III) and sulfate. Mackinawite evolved progressively into pyrrhotite. High-throughput 16S rRNA gene sequencing indicated that mackinawite-driven Cr(VI) reduction was mediated through synergistic interactions of microbial consortia; i.e. autotrophs as Acidovorax synthesized volatile fatty acids as metabolic intermediates, which were consumed by Cr(VI) reducers as Geobacter. Genes encoding enzymes for S oxidation (soxB) and Cr(VI) reduction (chrA, yieF) were upregulated. Cytochrome c participating in Fe(II) oxidation increased significantly. This work advances the development of sustainable techniques for Cr(VI) polluted groundwater remediation.

【 授权许可】

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