title: Removal of Acid Orange 7 from aqueous solution using magnetic graphene/chitosan: a promising nano-adsorbent.
abstract: Magnetic graphene/chitosan (MGCh) nanocomposite was fabricated through a facile chemical route and its application as a new adsorbent for Acid Orange 7 (AO7) removal was also investigated. After synthesis, the full characterization with various techniques (FTIR, XRD, VSM, and SEM) was achieved revealing many possible interactions/forces of dye-composite system. The results showed that, benefiting from the surface property of graphene oxide, the abundant amino and hydroxyl functional groups of chitosan, and from the magnetic property of Fe3O4, the adsorbent possesses quite a good and versatile adsorption capacity to the dye under investigation, and can be easily and rapidly extracted from water by magnetic attraction. The maximum absorption capacity was reached at initial pH 3 and 120min contact time. The batch adsorption experiments showed that the adsorption of the AO7 is considerably dependent on pH of milieu, amount of adsorbent, and contact time. The adsorption kinetics and isotherms were investigated to indicate that the kinetic and equilibrium adsorption were well-described by pseudo-first order kinetic and Langmuir isotherm model, respectively. The adsorption behavior suggested that the adsorbent surface was homogeneous in nature. The study suggests that the MGCh is a promising nano adsorbent for removal of anionic azo dyes from aqueous solution.
authors.affiliation: Department of Chemistry, Yadegar-e Emam Branch, Islamic Azad University, Tehran, Iran.
authors.forename: Shabnam
authors.initials: S
authors.lastname: Sheshmani
authors.affiliation: Department of Chemical Technologies, Iranian Research Organization for Science and Technology (IROST), Tehran, Iran. Electronic address: ashori@irost.org.
authors.forename: Alireza
authors.initials: A
authors.lastname: Ashori
authors.affiliation: Department of Chemistry, Yadegar-e Emam Branch, Islamic Azad University, Tehran, Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Hasanzadeh
mesh_terms: D000327:Adsorption; D001391:Azo Compounds / Q000302:isolation & purification*; D001557:Benzenesulfonates / Q000302:isolation & purification*; D048271:Chitosan / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D060328:Magnetic Phenomena; D060306:Magnetometry; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D014961:X-Ray Diffraction
chemical_list: D001391:Azo Compounds; D001557:Benzenesulfonates; D012996:Solutions; D014874:Water Pollutants, Chemical; D006108:Graphite; D048271:Chitosan; C014722:2-naphthol orange
keywords: Acid Orange 7; Adsorption; Chitosan; Graphene oxide; Nano-adsorbent