Reduction and transformation of Cr(VI)-associated ferrihydrite by Shewanella oneidensis MR-1: Kinetics and secondary minerals

Hu，Shiwen1,2; Wang，Qi1; Zhang，Hanyue3,4; Yang，Yang1; Chen，Guojun1; Wang，Shan1; Liu，Chongxuan2; Liu，Tongxu1

2024-06-01

10.1016/j.gca.2024.04.021

Geochimica et Cosmochimica Acta   影响因子和分区

0016-7037

Hexavalent chromium (Cr(VI)) could be sequestrated by soils via microbial reduction to Cr(III) and association with minerals, however, quantitative understanding of metal reducing bacteria on the coupled kinetics of Cr and Fe minerals is still lacking. Here, microbial-mediated ferrihydrite transformation and reductive sequestration of Cr(VI) were investigated with Shewanella oneidensis MR-1 under varying Cr/Fe ratios. Quantitative results depicted that the contents of magnetite from ferrihydrite transformation decreased from 70 % to 22 % after 288 h as Cr/Fe ratios increased from 0 to 8 × 10, and reductive transformation rates increased with decreasing Cr/Fe ratio. Elemental mapping and line scan analyses at nano-scale revealed that Cr(VI) was evenly combined within fresh ferrihydrite, and a part of produced Cr(III) was doped into the crystal lattice of magnetite and goethite. Cr may be sequestrated by secondary Fe minerals via structural substitution, surface complexation, and physical encapsulation. Microscopy-based results exhibited that more Fe minerals adsorbed on the surface of cell and less cells were lysed at low Cr/Fe ratios. Confocal laser scanning microscopy depicted that less cells were alive at high Cr/Fe ratios. The amplification of extracellular electron transfer-associated genes was downregulated as Cr/Fe ratios increased. The Cr/Fe ratios could affect cell activity, the combination with Fe minerals, and Mtr gene expression, thus controlling the reductive sequestration of Cr(VI) and phase transformation of ferrihydrite. A kinetic model has been established by combining elementary reductions, and it could well describe Cr(VI) reduction and Cr(III) incorporation under various Cr/Fe ratios during dissimilatory Fe reduction process. These findings could broaden our knowledge of quantifying the migration and transport of Cr in anoxic Cr-contaminated soil environments, and could be useful for simulating Cr dynamic behaviors in the natural soil, aquatic, and sediment environments.

Gene expression Microbial activity Nano-scale distribution Phase transformation Reductive sequestration of Cr(VI)

SCI

英语

其他

GEOSCIENCES

2-s2.0-85190471964

Scopus

1.National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China,Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management,Institute of Eco-environmental and Soil Sciences,Guangdong Academy of Sciences,Guangzhou,510650,China
2.State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control,School of the Environmental Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China
3.CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province,Chengdu Institute of Biology,Chinese Academy of Sciences,Chengdu,610041,China
4.University of Chinese Academy of Sciences,Beijing,100049,China

Hu，Shiwen,Wang，Qi,Zhang，Hanyue,et al. Reduction and transformation of Cr(VI)-associated ferrihydrite by Shewanella oneidensis MR-1: Kinetics and secondary minerals[J]. Geochimica et Cosmochimica Acta,2024,374:15-32.

Hu，Shiwen.,Wang，Qi.,Zhang，Hanyue.,Yang，Yang.,Chen，Guojun.,...&Liu，Tongxu.(2024).Reduction and transformation of Cr(VI)-associated ferrihydrite by Shewanella oneidensis MR-1: Kinetics and secondary minerals.Geochimica et Cosmochimica Acta,374,15-32.

Hu，Shiwen,et al."Reduction and transformation of Cr(VI)-associated ferrihydrite by Shewanella oneidensis MR-1: Kinetics and secondary minerals".Geochimica et Cosmochimica Acta 374(2024):15-32.