title: Fe3O4/cyclodextrin polymer nanocomposites for selective heavy metals removal from industrial wastewater.
abstract: In this work, carboxymethyl-β-cyclodextrin (CM-β-CD) polymer modified Fe(3)O(4) nanoparticles (CDpoly-MNPs) was synthesized for selective removal of Pb(2+), Cd(2+), Ni(2+) ions from water. This magnetic adsorbent was characterized by TEM, FTIR, XPS and VSM. The adsorption of all studied metal ions onto CDpoly-MNPs was found to be dependent on pH, ionic strength, and temperature. Batch adsorption equilibrium was reached in 45 min and maximum uptakes for Pb(2+), Cd(2+) and Ni(2+) in non-competitive adsorption mode were 64.5, 27.7 and 13.2 mg g(-1), respectively at 25 °C. Adsorption data were fitted well to Langmuir isotherm and pseudo-second-order models for kinetic study. The polymer grafted on MNPs enhanced the adsorption capacity because of the complexing abilities of the multiple hydroxyl and carboxyl groups in polymer backbone with metal ions. In competitive adsorption experiments, CDpoly-MNPs could preferentially adsorb Pb(2+) ions with an affinity order of Pb(2+)>>Cd(2+)>Ni(2+) which can be explained by hard and soft acids and bases (HASB) theory. Furthermore, we explored the recyclability of CDpoly-MNPs.
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117576, Singapore. cheazmb@nus.edu.sg
authors.forename: Abu Zayed M
authors.initials: AZ
authors.lastname: Badruddoza
authors.forename: Zayed Bin Zakir
authors.initials: ZB
authors.lastname: Shawon
authors.forename: Wei Jin Daniel
authors.initials: WJ
authors.lastname: Tay
authors.forename: Kus
authors.initials: K
authors.lastname: Hidajat
authors.forename: Mohammad Shahab
authors.initials: MS
authors.lastname: Uddin
mesh_terms: D000327:Adsorption; D003505:Cyclodextrins / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D006878:Hydroxides / Q000737:chemistry; D007220:Industrial Waste; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D019216:Metals, Heavy / Q000737:chemistry* / Q000302:isolation & purification*; D053761:Nanocomposites / Q000737:chemistry*; D009994:Osmolar Concentration; D013499:Surface Properties; D013696:Temperature; D062065:Wastewater / Q000737:chemistry*; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D003505:Cyclodextrins; D006878:Hydroxides; D007220:Industrial Waste; D058185:Magnetite Nanoparticles; D019216:Metals, Heavy; D062065:Wastewater; D014867:Water; D014874:Water Pollutants, Chemical; C031356:hydroxide ion