화학공학소재연구정보센터
Journal of Hazardous Materials, Vol.250, 345-353, 2013
Fe(II)-Al(III) layered double hydroxides prepared by ultrasound-assisted co-precipitation method for the reduction of bromate
Bromate is recognized as an oxyhalide disinfection byproduct in drinking water. In this paper, Fe(II)-Al(III) layered double hydroxides (Fe-Al LDHs) prepared by the ultrasound-assisted co-precipitation method were used for the reduction of bromate in solution. The Fe-Al LDHs particles were characterized by X-ray diffractometer, scanning electron microscopy and thermogravimetry-differential scanning calorimetry. It was found that ultrasound irradiation assistance promoted the formation of the hydrotalcite-like phase and then improved the removal efficiency of bromate. In addition, the effects of solid-to-solution ratio, contact time, initial bromate concentration, initial pH, coexisting anions on the bromate removal were investigated. The results showed the bromate with an initial concentration of 1.56 mu mol/L could be completely removed from solution by Fe-Al LDHs within 120 min. When the initial bromate concentration was 7.81 mu mol/L, the Fe-Al LDHs with irradiation time of 30 min exhibited the optimum removal efficiency and the bromate removal capacity (q(e)) was 6.80 mu mol/g. In addition, the appearance of sulfate and production of bromide were observed simultaneously in this process, which suggested that ion-exchange between sulfate and bromate, and the reduction of bromate to bromide by Fe2+ were the main mechanisms responsible for the bromate removal by Fe-Al LDHs. (C) 2013 Elsevier B.V. All rights reserved.