Chemical and microbial remediation of hexavalent chromium from contaminated soil and mining/metallurgical solid waste: A review

► The review focuses on the Cr speciation, uses, toxicity and remediation aspects. ► Assessed amount of hexavalent Cr in soils/metallurgical/other wastes and sites. ► Chemical and bioremediation processes for Cr(VI) are summarised in detail. ► Strategy for bio-remediation of Cr(VI) in different solid wastes is suggested. ► Capability of microbes for reducing Cr(VI) contamination described. ► Mechanism of microbial reduction of Cr(VI) to Cr(III) is included.