Adsorptive removal of thorium from aqueous solution using diglycolamide functionalized multi-walled carbon nanotubes

• Published in: Journal of radioanalytical and nuclear chemistry 2013-02, Vol.295 (2), p.1161-1169
• Main Authors: Deb, Ashish Kumar Singha, Mohanty, B. N., Ilaiyaraja, P., Sivasubramanian, K., Venkatraman, B.
• Format: Article
• Language: English
• Subjects: Adsorption; Aqueous solutions; Chemistry; Chemistry and Materials Science; Correlation; Diagnostic Radiology; Entropy; Hadrons; Heavy Ions; Inorganic Chemistry; Multi wall carbon nanotubes; Nanotubes; Nuclear Chemistry; Nuclear Physics; Physical Chemistry; Sorption; Thorium; Toy industry
• ISSN: 0236-5731; 1588-2780
• DOI: 10.1007/s10967-012-1899-3

Multi-walled carbon nanotubes (MWCNTs) were functionalized with diglycolamide (DGA) through chemical covalent route. The adsorption behavior of the DGA-functionalized-MWCNTs (DGA-MWCNTs) towards thorium from aqueous solution was studied under varying operating conditions of pH, concentration of thorium, DGA-MWCNTs dosages, contact time, and temperature. The effective range of pH for the removal of Th(IV) is 3.0–4.0. Kinetic data followed a pseudo-second-order model. The equilibrium data were correlated with the Langmuir, Freundlich, Dubinin-Radushkevich and Temkin models. The equilibrium data are best fitted with Langmuir model. The equilibrium Th(IV) sorption capacity was estimated to be 10.58 mg g −1 at 298 K. The standard enthalpy, entropy, and free energy of adsorption of the thorium with DGA-MWCNTs were calculated to be 8.952 kJ mol −1 , 0.093 kJ mol −1  K −1 and -18.521 kJ mol −1 respectively at 298 K. The determined value of sticking probability (0.072) and observed kinetic and isotherm models reveal the chemical adsorption of thorium on DGA-MWCNTs.