Advanced Treatment of Water Polluted by Hexavalent Chromium

ChromiumChromium is widely used in industries, which has sped up its environmental spread into water bodies. Because of Cr(VI)'s severe toxicity and classification as a human carcinogen by the United States Environmental Protection Agency, its detrimental effects on human health have prompted the necessity to decontaminate Cr(VI)Cr(VI) from water. Considering the limitations of the traditional methods for synchronous Cr(VI)Cr(VI) reductionReduction and Cr(III)Cr(III) immobilizationImmobilization, the advances reported for the Cr(VI) remediationRemediation have been reviewed in this chapter. Specifically, the chemical redoxChemical redox and adsorptionAdsorption reactions can be integrated into a single process for Cr(VI) decontaminationDecontamination by utilizing a range of substances, like amine/imine/thiol/sulfonic acid functionalized materials, bio-based materials, and natural minerals. The electrolysisElectrolysis process can also decontaminate Cr(VI) by the direct reductionReduction and precipitation of Cr(III)Cr(III) at the cathode owing to the locally strongly basic condition. The energy requirement for the electrolysisElectrolysis process can be avoided by establishing the bio-electrochemical system coupled with self-generating microbial biocathode. In addition, the photocatalytic reductionReduction approaches were also discussed among various photocatalysts. The advantages and disadvantages of available technologies for Cr(VI) contaminated water treatment were also discussed. Finally, future prospects and conclusion that support the effective decontaminationDecontamination of Cr(VI)Cr(VI) are summarized.