Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5157377 | Carbohydrate Polymers | 2017 | 32 Pages |
Abstract
Using Fe(III) salts and chitosan, nano iron oxide impregnated in chitosan bead (NIOC) was successfully synthesized for aqueous Cr(VI) detoxification via sol-gel technique without any additional crosslinking agent. NIOC characterization demonstrated that the iron in NIOC mainly existed as nano akaganeite (β-FeOOH) and complex with chitosan. Intraparticle diffusion was the major rate-limiting step. The maximal adsorption capacity was 69.8 mg/g (pH 5.0, 20 °C). Normal concentration of coexisting anions (SO42â, CO32â, SiO32â) showed insignificant competition, whereas PO43â suppressed the Cr(VI) sorption. Cr(VI)-loaded NIOC could be effectively regenerated by alkaline solutions. Column adsorption runs using granular NIOC could effectively treat about 1600 bed volumes of Cr(VI) solution (from 3.7 mg Cr/L in influent to <0.5 mg Cr/L in effluent). The Cr(VI) removal mechanisms involved the direct sorption of Cr(VI) (electrostatic attraction and ligand exchange), reduction of Cr(VI) into Cr(III) and re-sorption of Cr(III) via chelation on NIOC surface.
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Authors
Jianbo Lu, Kai Xu, Jinmei Yang, Yarong Hao, Fang Cheng,