A facile modification of cation exchange resin by nano-sized goethite for enhanced Cr(VI) removal from water.

A novel macroporous strong acidic cation exchange resin (D001) modified by nano-sized goethite ([email protected]) was fabricated by using a facile ethanol dispersion and impregnation method, and its efficiency for Cr(VI) removal was tested thereafter. Due to the dispersing effect of ethanol, FeOOH particles of 20-150 nm were coated on the D001 surfaces. The [email protected] obtained a Cr(VI) removal efficiency and capacity of 80.2% and 7.4 mg/g respectively, 5 times and 8 times higher than that of the pristine D001. The Cr(VI) removal by [email protected] followed the pseudo second-order kinetics and the Langmuir adsorption model. Column experiments also demonstrated that the [email protected] exhibited a much better ability to remove Cr(VI) as compared to the D001. Additionally, the [email protected] showed a potential for reusability and renewability. The adsorbed [email protected] could be easily desorbed by 0.1 M acetic acid and a reuse efficiency of 92.7% could be maintained after 4 desorption-adsorption cycles. The used [email protected] could be eluted by 0.1 M HCl to remove nFeOOH, and the renewed D001 could be recoated by nFeOOH and achieved a regeneration rate of 97.8% for Cr(VI) removal. The above results indicated that nano-sized goethite modification is a promising method to endow D001 with the ability to remove Cr(VI) from water.