title: Synthesis of mesoporous magnetic gamma-Fe2O3 and its application to Cr(VI) removal from contaminated water.
abstract: In this study, mesoporous magnetic iron-oxide (gamma-Fe(2)O(3)) was synthesized as an adsorbent for Cr(VI) removal. For material synthesis, mesoporous silica (KIT-6) was used as a hard template and to drive iron precursor into KIT-6, a 'greener', affinity based impregnation method was employed, which involved using a nonpolar solvent (xylene) and led to recycling of the solvent. The results of Cr(VI) removal experiments showed that the synthesized mesoporous gamma-Fe(2)O(3) has a Cr(VI) adsorption capacity comparable with 10nm nonporous gamma-Fe(2)O(3) but simultaneously has a much faster separation than 10nm nonporous gamma-Fe(2)O(3) in the presence of an external magnetic field under the same experimental conditions. Cr(VI) adsorption capacity onto the mesoporous gamma-Fe(2)O(3) increased with decreasing solution pH and could be readily regenerated. Therefore, mesoporous gamma-Fe(2)O(3) presents a reusable adsorbent for a fast, convenient, and highly efficient removal of Cr(VI) from contaminated water.
authors: Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China.
authors: Peng
authors: P
authors: Wang
authors: Irene M C
authors: IM
authors: Lo
mesh_terms: D000327:Adsorption; D002857:Chromium / Q000032:analysis*; D003247:Conservation of Natural Resources; D005290:Ferric Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D055772:Green Chemistry Technology / Q000379:methods; D008280:Magnetics; D008855:Microscopy, Electron, Scanning; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
chemical_list: D005290:Ferric Compounds; D014874:Water Pollutants, Chemical; D002857:Chromium; C074702:chromium hexavalent ion; C000499:ferric oxide