Sequestration and recovery of thorium ions using a recyclable, low-cost, glutathione-based magnetic nanocomposite: Experimental study and statistical modeling

Abstract

Efficient removal and recovery of thorium from water resources is necessary to resolve the problem of radioactive contamination. To address this issue, magnetically separable Glu@MNPs have been fabricated and efficiently utilized for the removal of Th(IV). 99.40 % removal of Th(IV) by Glu@MNPs could attain an equilibrium state within 10 min at a dosage level of 6 mg for 20 ml of 50 mg/L thorium solution at pH 4 and 25 °C. It obeys Langmuir isotherm with maximum adsorption capacity of 636.94 mg g−1, which is independent of temperature variation. Kinetically, the adsorptive performance of Glu@MNPs fits well in the pseudo-second-order equation. The high removal efficiency is due to the existence of several types of functional groups on the surface of Glu@MNPs, which provide electrostatic attraction, and vander wall forces between adsorbate and adsorbent. The optimum conditions obtained from Box-Behnken composite design model was well matched with batch adsorption studies. Further, the results obtained for removal of Th(IV) by UV–vis spectroscopy matched well with ICP-OES. The removal efficiency still remained high (85.65 %) even after 10 adsorption–desorption cycles. Thus, Glu@MNPs acts as a timesaving adsorbent for sequestration of Th(IV) from an aqueous media with excellent removal performance.