Use of modified wheat bran for the removal of chromium(VI) from aqueous solutions

Novel adsorbents, wheat bran (WB) and modified wheat bran (M-WB) with tartaric acid were developed and Cr(VI) adsorption was investigated by changing various parameters. The adsorption increased with contact time and become optimum at 180 min for WB and 200 min for M-WB. When the pH of the solution phase increased, some of toxic Cr(VI) reduced into less toxic Cr(III) on the WB surface. The maximum removal of Cr(VI) from the solution having an initial Cr(VI) concentration of 200 mg L(-1) was obtained at pH 2.0 as 51.0% and 90.0% for WB and M-WB, respectively. Isotherm data of Cr(VI) adsorption on WB and M-WB was described by the Freundlich adsorption model. The adsorption capacity of 4.53 mg of Cr(VI)/g for WB and 5.28 mg of Cr(VI)/g for M-WB was obtained at pH 2 and 2.2 respectively.