Development of maghemite nanoparticles supported on cross-linked chitosan (γ-Fe2O3@CS) as a recoverable mesoporous magnetic composite for effective heavy metals removal

(2017) Development of maghemite nanoparticles supported on cross-linked chitosan (γ-Fe2O3@CS) as a recoverable mesoporous magnetic composite for effective heavy metals removal. Journal of Molecular Liquids.

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Abstract

A mesoporous magnetic composite, γ-Fe2O3-functionalized cross-linked chitosan (γ-Fe2O3@CS), was developed as an efficient adsorbent to remove cadmium (Cd2 +) ions from contaminated water media. The as-prepared composite was characterized by FESEM, TEM, EDS, VSM, BET and XRD techniques. Several parameters affecting the removal efficiency including surface area, solution pH, contact time, adsorbent dose, initial Cd2 + concentration and temperature were evaluated and discussed. The average crystallite size of γ-Fe2O3 was found to be 26.5 nm. The highest magnetization saturation of adsorbent was 25.1 emu/g. The adsorption rate belonged γ-Fe2O3@CS composite was much higher than that γ-Fe2O3 and CS, which reflects a synergistic effect between the maghemite and CS particles on the removal of Cd2 +. Based on the adsorption capacity normalized by surface area, the value of Cd2 + adsorbed on adsorbents follows the order of γ-Fe2O3@CS > CS > γ-Fe2O3. The equilibrium time was 60 min and the monolayer maximum adsorption capacity was found to be 15.2 mg/g. Under optimized experimental conditions, complete removal of 5 mg/L of Cd2 + was achieved. Cycling tests revealed that γ-Fe2O3@CS was recyclable to remove Cd2 + ions during five consecutive cycles and the removal efficiency still remains at 78.3. Kinetic and isotherm of adsorption were in good agreement with pseudo-second-order and Langmuir models, respectively. The adsorption process was endothermic and spontaneous in nature. Cd2 + adsorption mechanism on γ-Fe2O3@CS follows ion-exchange and monolayer chemical adsorption. © 2017 Elsevier B.V.

Item Type: Article
Additional Information: cited By 3
Keywords: Adsorbents; Adsorption; Cadmium compounds; Chitin; Chitosan; Crosslinking; Crystallite size; Dyes; Efficiency; Heavy metals; Ion exchange; Ions; Iron compounds; Magnetism; Metal nanoparticles; Monolayers; Nanomagnetics; Nanoparticles; Saturation magnetization; Water pollution, Adsorption capacities; Cross linked chitosan; Experimental conditions; Heavy metals removals; Isotherm of adsorption; Maghemite nanoparticle; Magnetic chitosan; Magnetization-saturation, Chemicals removal (water treatment)
Subjects: Environmental health
Divisions: Education Vice-Chancellor Department > Faculty of Health > Department of Environmental Health Engineering
Depositing User: دکتر مهری غلامی
URI: http://eprints.abzums.ac.ir/id/eprint/2280

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