Research on Adsorption of Chromium (VI) from Wastewater by Anion Exchange Resin

The use of a strong anion exchange resin (Spectra/Gel IE 1x8) as an adsorbent for the efficient removal of Cr(VI) ions from synthetic wastewater solutions has been studied.Initial Cr(VI) ions concentrations in batch tests ranged from 25 to 300 mg/L. Various factors impacting Cr(VI) adsorption, such as solution pH, Cr(VI) and adsorbent concentrations, and contact time, were investigated. The results showed that Cr(VI) was successfully retained by the resin. For initial Cr(VI) concentrations up to 100 mg/L, equilibrium was reached in 30 minutes. The equilibrium data for adsorption of Cr(VI) was fitted with both Langmuir and Freundlich isotherms, however, the Langmuir isotherm model was shown to be more suitable for Cr(VI) adsorption, with a maximum adsorption capacity of 173.8 mg/g. The adsorption process followed second order kinetics. After three regeneration cycles, the resin was regenerated with 4M NaOH as an eluent and retained a Cr(VI) adsorption effectiveness of more than 83%.