Performance comparison of activated carbon and ferric oxide-hydroxide–activated carbon nanocomposite as vanadium(v) ion adsorbents

Abstract

Recently, a great deal of attention has been paid to water treatment using nanoparticles such as ferric nanoparticles. In this work, a ferric oxide-hydroxide–activated carbon nanocomposite (Fe–AC) was synthesized via a simple and low- temperature method and characterized using BET, XRF, FTIR, XRD and SEM techniques. In order to compare the performance of commercial activated carbon (CAC) and Fe–AC for vanadium ion adsorption, the influences of various adsorption parameters such as pH, contact time, initial concentration of vanadium and temperature were investigated. The kinetic data confirmed the validity of the pseudo-second-order kinetic model for CAC and Fe–AC. The sorption isotherms were studied using Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherm models. The equilibrium data was described with significant accuracy by using the Freundlich model. The results showed that CAC had a vanadium ion adsorption capacity of 37.87 mg g⁻¹, while Fe–AC was able to adsorb 119.01 mg g⁻¹ of vanadium. The determination of different thermodynamic parameters indicated that the vanadium ion adsorption was feasible and spontaneous and that both adsorbents had an exothermic nature.