ارزیابی عملکرد رزین نانو ذرات آهن (لیواتیت FO36) در کاهش کروم شش ظرفیتی از محيط مايي

Abstract

Introduction: Chromium (VI) can be removed from aqueous solutions using different but expensive methods. In this study, a new method using Liwatit exchange resin was developed to remove chromium (VI). Methods: Removing the chromium (VI) ion from the aqueous solution was studied via considering the effect of absorbent, initial chromium concentration, contact time and pH in batch phase. Equilibrium constant which depends on the capacity of change was calculated using Longmuir adsorption isotherm. Results: The Batch ion-exchange process was relatively fast, and it reached equilibrium after about 90 minutes of contact. The ion-exchange process, which is pH dependent show maximum removal of Cr(VI) in the pH range 5.0-8.0 for an initial Cr(VI) concentration of 0.5 mg L -1 . Lewatit FO 36 shows high bonding constant. The equilibrium related to its ion-exchange capacity and the amount of the ion exchange was obtained by using the plots of the Langmuir adsorption isotherm. It was observed that the maximum ion-exchange capacity of 0.29 mmol of Cr (VI)/g for Lewatit FO 36 was achieved at optimum pH value of 6.0. The ion exchange of Cr (VI) on this cation-exchange resin followed first-order reversible kinetics. Conclusion: According to the results, because of its regeneration characteristic, Liwatit FO36 resin can be used as a convenient optimum to reduce the level of Cr(VI) from the aqueous solutions in the contaminated places throuhout the country, particularly South Khorasan province, where the problem of chromium in fresh water is ubiquitous.