Adsorptive Bromate Removal from Aqueous Solution by Commercial Strongly Basic Resin Impregnated with Hydrated Ferric Oxide (HFO): Kinetics and Equilibrium Studies

Commercial strongly basic resin D201-Cl was impregnated with hydrous ferric oxide (HFO) in FeCl₃–HCl–NaCl solution for absorptive removal of bromate from aqueous solution. The influences of initial bromate concentration, contact time, initial pH, temperature, and competing anions on the uptake of bromate by HFO-impregnated resin D201-Cl (HFO-201) were investigated by batch adsorption experiments. Experimental results showed that the adsorption process could be described by pseudo-first-order kinetics and be divided into three stages according to the intraparticle diffusion parameter. The maximum adsorption potential of HFO-impregnated resin for bromate was 292.81 mg·g^–1 at 298 K, which is much greater than those reported in previous studies. The experimental data fitted well to the Redlich–Peterson isotherm model (R² > 0.99). Thermodynamic parameters such as free energy, enthalpy, and entropy demonstrated that bromate adsorption on HFO-201 was spontaneous and exothermic and occurred by physisorption. Meanwhile, HFO-201 maintained greater adsorption capacity for bromate in salt coexisting solution. Results of the present study suggest that the cheap and facile HFO-impregnated resin possesses great potential for bromate removal from drinking water.