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 UO₂ ²⁺ion. The effect of several parameters was optimized by central composite design (CCD) and the respective value was set as follows: adsorbent mass (5mg), contact time (10min), initial UO₂ ²⁺ions concentration (2mgL^-1) and initial ECR concentration (8mgL^-1). It was found that UO₂ ²⁺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 (5mg) of AgOH-NPs-MWCNTs is sufficient for removal of high amount of UO₂ ²⁺ion (R>96% and adsorption capacity of 140mgg^-1) in a 10min contact time.