摘要
Chromate[Cr(VI)]contamination in groundwater is a global environmental challenge.Traditional elemental sulfur-based biotechnologies for Cr(VI)removal depend heavily on the synthesis of dissolved organic carbon to fuel heterotrophic Cr(VI)reduction,a bottleneck in the remediation process.Here we show an alternative approach by leveraging sulfur-disproportionating bacteria(SDB)inherent to groundwater ecosystems,offering a novel and efficient Cr(VI)removal strategy.We implemented SDB within a sulfur-packed bed reactor for treating Cr(VI)-contaminated groundwater,achieving a notable removal rate of 6.19 mg L^(-1) h^(-1) under oligotrophic conditions.We identified the chemical reduction of Cr(VI)via sulfide,produced through sulfur disproportionation,as a key mechanism,alongside microbial Cr(VI)reduction within the sulfur-based biosystem.Genome-centric metagenomic analysis revealed a symbiotic relationship among SDB,sulfur-oxidizing,and chromate-reducing bacteria within the reactor,suggesting that Cr(VI)detoxification by these microbial communities enhances the sulfurdisproportionation process.This research highlights the significance of sulfur disproportionation in the cryptic sulfur cycle in Cr(VI)-contaminated groundwater and proposes its practical application in groundwater remediation efforts.
基金
the support from the National Natural Science Foundation of China(No.51978289,U23A2049)
the Science and Technology Planning Project of Guangdong Province(2021A0505020010).
