Removal Of Bromate From Water By Modified Strong Basic Anion Resin

Water is the source of life.Drinking water quality is closely related to human life and health.With increasingly serious water pollution and higher requirement for high quality drinking water,drinking water treatment technology has to be improved.As a strong oxidant,ozone can effectively remove the odor and color,and degrade some harmful organic pollutants.However,when the bromine ion(Br-)in drinking water reaches a certain concentration,the reaction between bromine ion and ozone in water leads to the formation of bromate,a carcinogenic disinfection by-product.Therefore,it is urgent toexplore the effective technology to remove the bromate in water.In this paper,HFO-201,which was the strong basic anion exchange resin(D201-CI)impregnated hydrous ferric oxide(HFO),was used to remove bromate from the water.Hydrous ferric oxide(HFO)was supported on the strongly basic resin(D201-C1)in FeCl3-HCl-NaCl 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-C1(HFO-201)were investigated by batch adsorption experiments.The static study of bromate removal by HFO-201 was carried on in term of the effect of single factor,such as:contact time,initial concentration,pH,temperature and coexisting ions.The kinetics,isotherm and thermodynamics were investigated,as well as the HFO-201 regeneration.The experimental results showed that with the increase of the initial concentration of bromate,the adsorption rate of bromate was faster,and the adsorption equilibrium time is about 200 minutes.HFO-201 had a higher adsorption capacity of bromate within the pH 4.0-9.0,and the residual bromate concentration is lower than or close to the maximum contaminant level of 10?g/L.The maximum adsorption potential of HFO-201 for bromate was 292.81 mg g'1 at 298 K,which is much greater than those reported in previous studies.The interference by the higher concentration of coexisting anions was stronger.The effect of nitrate,sulfate and chloride ions on the bromate removal by HFO-201 was NO3->SO42->Cl-.The adsorption process could be described by pseudo-first-order kinetics and be divided into three stages according to the intra-particle diffusion parameter.The experimental data fitted well to the Redlich-Peterson isotherm model(R2>0.99).Thermodynamic parameters such as free energy,enthalpy,and entropy,?H0<0,?G0<0 demonstrated that bromate adsorption on HFO-201 was spontaneous,exothermic and occurred by physisorption.This study shows that the cheap and facile HFO-impregnated resin possesses great potential for bromate removal from drinking water.