Adsorption of reduced chromium(VI) ions by vitamin C tablets onto a tellurato‐functionalized cellulose derivative and its composite with Cyanobacteria green algae in aqueous media. Issue 4 (18th February 2021) - Saad, Eman M.
Abstract: The removal of toxic chromium(VI) ions from wastewaters in the environment are of considerable importance throughout the world as these ions are known to cause severe medical problems in living organisms. This article describes a novel reduction process for Cr(VI) ions to the less toxic Cr(III) ions in typical wastewaters by using ecofriendly vitamin C tablets as a source of ascorbic acid, which completely reduces Cr(VI) to Cr(III) ions. The efficient adsorption of reduced Cr(VI) ions onto cellulose functionalized with sodium‐tellurate, Cell‐TeO(OH)4 (ONa)/Cell‐Cl {Cell‐Te}, both in the absence and the presence of Cyanobacteria green algae (CBGA), has been accomplished. This green algae has polysaccharide binding groups that enhance the adsorption of heavy metal ions. The uptake of reduced Cr(VI) ions by the two sorbents are dependent on the initial pH, contact time, temperature, presence of foreign ions, sorbent dose, and initial Cr(VI) ion concentration. The maximum uptakes of reduced Cr(VI) ions by {Cell‐Te} and Cell‐TeO(OH)4 (ONa)/Cell‐Cl:CBGA; 3:2 w/w {Cell‐Te‐CBGA} are 56.5 and 88.7 mg g −1, respectively. The hydroxyl and amide groups on the surface of the CBGA most probably play a significant role in facilitating the adsorption capacities of the two sorbents toward Cr(VI) ions. Abstract : Effect of concentration of ascorbic acid on the reduction of Cr(VI) to Cr(III) at pH 7, temperature 25°C, for 30 min.