title: Stability and pH-independence of nano-zero-valent iron intercalated montmorillonite and its application on Cr(VI) removal.
abstract: Composite of nano-zero-valent iron and montmorillonite (NZVI/MMT) was prepared by inserting NZVI into the interlayer of montmorillonite. The unique structure montmorillonite with isolated exchangeable Fe(III) cations residing near the sites of structural negative charges inhibited the agglomeration of ZVI and result in the formation of ZVI particles in the montmorillonite interlayer regions. NZVI/MMT was demonstrated to possess large specific surface area and outstanding reducibility that encourage rapid and stable reaction with Cr (VI). Besides, the intercalation also makes NZVI well dispersed and more stable in the interlayer, thereby improving the reaction capacity by 16 times. The effects of pH value, initial concentration of Cr (VI) and reaction time on Cr (VI) removal have also been investigated in detail. According to PXRD and XPS characterization, NZVI/Cr (VI) redox reaction occurred in the interlayer of MMT. The study of NZVI/MMT is instrumental to the development of remediation technologies for persistent environmental contaminants.
authors.affiliation: School of Materials Sciences and Technology, China University of Geosciences, Beijing, China 100083.
authors.forename: Limei
authors.initials: L
authors.lastname: Wu
authors.affiliation: School of Materials Sciences and Technology, China University of Geosciences, Beijing, China 100083. Electronic address: lbliao@cugb.edu.cn.
authors.forename: Libing
authors.initials: L
authors.lastname: Liao
authors.affiliation: School of Materials Sciences and Technology, China University of Geosciences, Beijing, China 100083. Electronic address: guochenglv@cugb.edu.cn.
authors.forename: Guocheng
authors.initials: G
authors.lastname: Lv
authors.affiliation: 1D Nanomaterials Group, National Institute for Material Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
authors.forename: Faxiang
authors.initials: F
authors.lastname: Qin
mesh_terms: D001546:Bentonite / Q000737:chemistry*; D002857:Chromium / Q000032:analysis / Q000737:chemistry*; D052918:Environmental Restoration and Remediation / Q000379:methods; D006863:Hydrogen-Ion Concentration; D007364:Intercalating Agents / Q000737:chemistry; D007501:Iron / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry; D010084:Oxidation-Reduction; D013499:Surface Properties; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D007364:Intercalating Agents; D014874:Water Pollutants, Chemical; D002857:Chromium; D001546:Bentonite; C074702:chromium hexavalent ion; D007501:Iron
keywords: Hexavalent chromium; Intercalated; Montmorillonite; Nanoscale zerovalent iron; Redox reaction