School of Minerals Processing and Bioengineering, Key Laboratory of Biohydrometallurgy of Ministry of Education, Central South University, Changsha, 410083, China.
Faculty of Agriculture, Forestry and Food Engineering, Yibin University, Yibin, 644000, China.
Chemosphere. 2022 Dec;308(Pt 1):136228. doi: 10.1016/j.chemosphere.2022.136228. Epub 2022 Aug 27.
Pyrite was applied to Cr(VI) bioremediation as an inorganic electron donor due to the ability to provide electrons, while the role of pyrite in Cr(VI) bioremediation where organics as electron donors remains unknown. Herein a pyrite-based Cr(VI) bioreduction process in the sediment system containing lactate was demonstrated to be effective to detoxify Cr(VI): over 2200 mg L Cr(VI) was continuously removed within 210 h with high reactivity (10.5 mg/(L·h)) all along. High-throughput 16S rDNA gene sequencing indicated that the pyrite could shape a functioning community that electrochemically active bacteria dominated (such as Fusibacter sp. and Rhodobacteraceae) instead of iron-oxidizing bacteria and sulfur-oxidizing bacteria. Mineralogy analysis results indicated that Fe(III), S and S formed on the pyrite surface after the oxidation of Cr(VI) might serve as the electron acceptor of microflora, then the S and Fe(II) with strong Cr(VI) reduction ability were formed by microbial reduction to enhance the removal of Cr(VI). This study provides new insights into thoroughly understanding the role of pyrite in the practical application of Cr(VI) bioreduction.
黄铁矿作为一种无机电子供体被应用于 Cr(VI)的生物修复，因为它能够提供电子，而黄铁矿在以有机物作为电子供体的 Cr(VI)生物修复中的作用仍不清楚。在此，证明了在含有乳酸盐的沉积物系统中，基于黄铁矿的 Cr(VI)生物还原过程是有效的解毒 Cr(VI)的方法：在 210 小时内，持续去除了超过 2200mg/L 的 Cr(VI)，反应活性很高（10.5mg/（L·h））。高通量 16S rDNA 基因测序表明，黄铁矿可以形成一个功能群落，其中电化学活性细菌占主导地位（如 Fusibacter sp. 和 Rhodobacteraceae），而不是铁氧化菌和硫氧化菌。矿物学分析结果表明，Cr(VI)氧化后在黄铁矿表面形成的 Fe(III)、S 和 S 可能作为微生物的电子受体，然后通过微生物还原形成具有较强 Cr(VI)还原能力的 S 和 Fe(II)，从而增强 Cr(VI)的去除。本研究为深入了解黄铁矿在 Cr(VI)生物还原实际应用中的作用提供了新的见解。
