Chemical Engineering Journal, Vol.273, 296-306, 2015
Efficient removal of radioactive uranium from solvent phase using AgOH-MWCNTs nanoparticles: Kinetic and thermodynamic study
Silver hydroxide nanoparticles (AgOH-NPs) were efficiently festooned onto multiwalled carbon nanotubes (MWCNTs) and characterized by analytical techniques such as SEM, FT-IR and BET analysis. These were used for the removal of radioactive uranium(VI) followed by its complexation with eriochrome cyanine R in the presence of cetyl trimethyl ammonium bromide (CTAB). The adsorption process and its mass transfer were accelerated and assisted using ultrasound waves. The AgOH-NPs-MWCNTs has large surface area that was suitable for qualitative and quantitative removal of UO22+ ion. The effect of several parameters was optimized by central composite design (CCD) and the respective value was set as follows: adsorbent mass (5 mg), contact time (10 min), initial UO22+ ions concentration (2 mg L-1) and initial ECR concentration (8 mg L-1). It was found that UO22+ ion adsorption follow combination of the pseudo-second-order rate equation and intraparticle diffusion model. Equilibrium data well fitted with the Freundlich model and reveal that the small amount (5 mg) of AgOH-NPs-MWCNTs is sufficient for removal of high amount of UO22+ ion (R > 96% and adsorption capacity of 140 mg g(-1)) in a 10 min contact time. (C) 2015 Elsevier B.V. All rights reserved.
Keywords:Nanoparticle;Radioactive uranium;Cationic surfactant;Experimental design;Central composite design (CCD)