Fe3O4 and gamma-Fe2O3 nanoparticles for the adsorption of Co2+ from aqueous solution
2006 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 298, no 2, 501-507 p.Article in journal (Refereed) Published
The adsorption of Co2+ ions from nitrate solutions using iron oxide nanoparticles of magnetite (Fe3O4) and maghemite (gamma-Fe2O3) has been studied. The adsorption of Co2+ ions on the surface of the particles was investigated under different conditions of oxide content, contact time, Solution pH. and initial Co2+ ion concentration. It has been found that the equilibrium can be attained in less than 5 ruin. The maximum loading capacity of Fe3O4 and gamma-Fe2O3 nanoparticles is 5.8 x 10(-5) and 3.7 x 10(-5) mol m(-2), respectively, which are much higher than the previously Studied. iron oxides and conventional ion exchange resins. Co2+ ions were also recovered by dilute nitric acid from the loaded gamma-Fe2O3 and Fe3O4 with an efficiency of 86 and 30%. respectively. That has been explained by the different mechanisms by including both the surface and Structural loadings of Co2+ ions. The Surface adsorption of Co2+ on Fe3O4 and gamma-Fe2O3 nanoparticles has been found to have the same mechanism of ion exchange reaction between Co2+ in the solution and proton bonded on the particle Surface. The conditional equilibrium constants of surface 2-adsorption of Co2+ on Fe3O4 and gamma-Fe-O-2(3) nanoparticles have been determined to be log K = -3.3 +/- 0.3 and -3.1 +/- 0.2, respectively. The Structural loading of Co2+ ions into Fe3O4 lattice has been found to be the ion exchange reaction between CO2+ and Fe2+ while that into gamma-Fe2O3 lattice to fill its vacancy. The effect of temperature on the adsorption of Co2+ was also investigated, and the value of enthalpy change was determined to be 19 kJ mol(-1)
Place, publisher, year, edition, pages
2006. Vol. 298, no 2, 501-507 p.
adsorption, magnetite, maghemite, cobalt(II), nanoparticles, magnetite particles, reaction-kinetics, iron-oxide, ions, hematite, goethite, cadmium, desorption, cobalt(ii), sorption
IdentifiersURN: urn:nbn:se:kth:diva-15713DOI: 10.1016/j.jcis.2005.12.057ISI: 000237909100001ScopusID: 2-s2.0-33747758390OAI: oai:DiVA.org:kth-15713DiVA: diva2:333755
QC 201005252010-08-052010-08-052010-09-24Bibliographically approved