The excursion covered for the elimination of chromate by exploring the coordination mechanisms between chromium species and various functional groups

• Published in: Coordination chemistry reviews 2021-06, Vol.437, p.213868, Article 213868
• Main Authors: Ifthikar, Jerosha, Ibran Shahib, Irshad, Jawad, Ali, Gendy, Eman A., Wang, Siqi, Wu, BeiBei, Chen, Zhuqi, Chen, Zhulei
• Format: Article
• Language: English
• Subjects: Coordination; Cr(VI) reduction coupled adsorption; Electron donor; Functional group; Recycle and regeneration
• ISSN: 0010-8545; 1873-3840
• DOI: 10.1016/j.ccr.2021.213868

[Display omitted] •Investigated the major role of active functionalities for the chromate removal.•Elucidated the detailed reaction mechanisms of the applied systems.•Conducted the detailed comparison among various functionalities.•Provided significant insights and perspectives for future studies. Highly efficient elimination of anionic chromate remains a critical task from the biological and ecological perspective owing to their carcinogenic effects on the biosphere and ecosphere. In literature, varieties of functional materials have been applied to remove Cr(VI) from the environmental sources. In which the chemical reduction of Cr(VI) to Cr(III) by a reductant and simultaneous adsorption of Cr species is an effective technique for the removal of Cr(VI). Many effective reductants were applied in the past years, which could be categorized according to their active functional atom/group. Although very few studies illustrated the complete coordination mechanisms between Cr ions and functional groups during the reduction coupled adsorption. This review focuses on recently investigated Cr(VI) reduction coupled adsorption systems based on the electron donor (reductant) functionalities with the interactions of Cr2O72−, CrO42− and Cr3+ ions by the metal and nonmetal functional groups. Also, the removal capacity and equilibrium time were analyzed based on the findings from isotherm and kinetic studies. To conclude, we offered our insights based on the coordination of chromium species with various functionalities into future research prospects and issues in the hope of motivating more researchers to involve in this new area of functional materials for environmental pollution control.