title: Synergistic removal of Pb(II), Cd(II) and humic acid by Fe3O4@mesoporous silica-graphene oxide composites.
abstract: The synergistic adsorption of heavy metal ions and humic acid can be very challenging. This is largely because of their competitive adsorption onto most adsorbent materials. Hierarchically structured composites containing polyethylenimine-modified magnetic mesoporous silica and graphene oxide (MMSP-GO) were here prepared to address this. Magnetic mesoporous silica microspheres were synthesized and functionalized with PEI molecules, providing many amine groups for chemical conjugation with the carboxyl groups on GO sheets and enhanced the affinity between the pollutants and the mesoporous silica. The features of the composites were characterized using TEM, SEM, TGA, DLS, and VSM measurements. Series adsorption results proved that this system was suitable for simultaneous and efficient removal of heavy metal ions and humic acid using MMSP-GO composites as adsorbents. The maximum adsorption capacities of MMSP-GO for Pb(II) and Cd (II) were 333 and 167 mg g(-1) caculated by Langmuir model, respectively. HA enhances adsorption of heavy metals by MMSP-GO composites due to their interactions in aqueous solutions. The underlying mechanism of synergistic adsorption of heavy metal ions and humic acid were discussed. MMSP-GO composites have shown promise for use as adsorbents in the simultaneous removal of heavy metals and humic acid in wastewater treatment processes.
authors.affiliation: The Institute for Biomedical Engineering and Nano Science, Tongji University School of Medicine, Shanghai, PR China.
authors.forename: Yilong
authors.initials: Y
authors.lastname: Wang
authors.forename: Song
authors.initials: S
authors.lastname: Liang
authors.forename: Bingdi
authors.initials: B
authors.lastname: Chen
authors.forename: Fangfang
authors.initials: F
authors.lastname: Guo
authors.forename: Shuili
authors.initials: S
authors.lastname: Yu
authors.forename: Yulin
authors.initials: Y
authors.lastname: Tang
mesh_terms: D002104:Cadmium / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D006812:Humic Substances; D007854:Lead / Q000737:chemistry*; D019216:Metals, Heavy / Q000737:chemistry; D010087:Oxides / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D014873:Water Pollutants / Q000737:chemistry
chemical_list: D006812:Humic Substances; D019216:Metals, Heavy; D010087:Oxides; D014873:Water Pollutants; D002104:Cadmium; D007854:Lead; D012822:Silicon Dioxide; D006108:Graphite