title: Impacts of amount of impregnated iron in granular activated carbon on arsenate adsorption capacities and kinetics.
abstract: Iron-impregnated granular activated carbons (Fe-GAC) can remove arsenic effectively from water. In this study, Fe-GACs with iron content of 1.64 to 28.90% were synthesized using a new multi-step procedure for the investigation of effects of iron amount on arsenic adsorption capacities and kinetics. Langmuir model satisfactorily fit arsenic adsorption on Fe-GACs. The maximum arsenic adsorption capacity (q(m)) increased significantly with iron impregnation and reached 1,867 to 1,912 microg/g with iron content of 9.96 to 13.59%. Further increase of iron content (> 13.59%) caused gradual decrease of q(m). It was found that the amount of impregnated iron showed little impact on the affinity for arsenate. Kinetic study showed that the amount of impregnated iron affected the arsenic intraparticle diffusion rate greatly. The pseudo-second-order kinetic model fit arsenic adsorption kinetics on Fe-GACs better than the pseudo-first-order model. The arsenic adsorption rate increased with increasing of iron content from 1.64% to 13.59%, and then decreased with more impregnated iron (13.59 to 28.90%).
authors.affiliation: School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China.
authors.forename: Qigang
authors.initials: Q
authors.lastname: Chang
authors.forename: Wei
authors.initials: W
authors.lastname: Lin
authors.forename: Wei-Chi
authors.initials: WC
authors.lastname: Ying
mesh_terms: D000327:Adsorption; D001149:Arsenates / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000737:chemistry; D018508:Water Purification / Q000379:methods
chemical_list: D001149:Arsenates; D014874:Water Pollutants, Chemical; D002244:Carbon; D007501:Iron