Modeling of adsorption isotherms and kinetics of uranium sorption by magnetic ion imprinted polymers

Abstract

Application of magnetic U(VI) ion imprinted polymers (IIPs) coated on magnetic nanoparticles was investigated for pre-concentration and determination of U(VI) ions in aqueous solutions. The scanning electron micrographs revealed the microporosity of the adsorbent. Uranium leaching was successful as the energy-dispersive X-ray spectra showed. The Brunauer–Emmett–Teller (BET) surface area improved by more than 13-fold (83.1 and 6.2 m² g⁻¹ for the leached and unleached magnetic IIP, respectively). U(VI) uptake was optimized using batch experiments with parameters affecting the uptake performance, such as initial uranium concentration, pH, contact time, and adsorbent dose investigated. Pseudo-second-order kinetics and the Langmuir isotherm model best fitted the experimental data. The maximum adsorption capacity of uranium onto the activated magnetic IIP reached 5.4 mg g⁻¹. The selectivity order was determined to be U(VI) > Ni(II) > Th(IV).

Keywords:

• complexation
• uranium
• magnetic
• imprinted polymers
• arsenazo III dye

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors would like to thank the University of Witwatersrand for providing financial support through the Wits Postgraduate Merit Award and the Water Research Commission of South Africa (WRC project number 2014) for funding the project.