A review of chemical, electrochemical and biological methods for aqueous Cr(VI) reduction

► Cr(VI) is of particular environmental concern due to its toxicity and mobility. ► Cr(VI) is very mobile and toxic in the environment, Cr(III) is not. ► Reducing Cr(VI) to Cr(III) reduces its toxicity and mobility. ► Cr(VI) is challenging to remove from wastewater since does not precipitate. ► We describe the technologies available to efficiently reduce hexavalent chromium.