Microbial strategies for effective hexavalent chromium removal: A comprehensive review

• Summarized the microbial-mediated detoxification pathways of Cr(VI). • Microbial-mediated detoxification mechanism of Cr(VI) have been included. • Current problems and bottlenecks in the field were discussed. • Prospects for chromium pollution treatment and future research perspectives. Chromium, a ubiquitous heavy metal, finds extensive utilization in industrial sectors such as tanning, electroplating, stainless steel production, paints, and fertilizers. Due to its apparent biological toxicity, Cr(Ⅵ) is recognized as a predominant contaminant, inflicting severe impacts on both the environment and biological systems. The remediation of Cr(Ⅵ) serves not only to alleviate its ecological ramifications but also to engender substantial economic savings. Nevertheless, extant physicochemical techniques employed for Cr(Ⅵ) elimination are marred by environmental unfriendliness and reliant on copious chemical agents. In contrast, microorganisms, acclaimed for its cost-effectiveness, good environmental compatibility, and conspicuous removal efficacy, stands as an efficacious and practicable approach for Cr(Ⅵ) pollution mitigation. The operation mechanisms of this strategy encompass microbial adsorption and reduction, etc., facilitating a considerable reduction in hexavalent chromium content. This comprehensive review meticulously delineates the physicochemical attributes and origins of Cr(Ⅵ), alongside its implications for the ecological milieu. Moreover, it accentuates the adsorption and reduction mechanisms pertinent to microbial Cr(Ⅵ) abatement, elucidating the influence of environmental factors and external agents on removal efficacy. Ultimately, considering the non-renewable nature of chromium as a resource and combining with the current research status, some future research prospects are proposed, offering forward-looking perspectives for future research endeavors.