Dithiocarbamate functionalised crosslinked polyacrylamide for separation and pre-concentration of uranium (VI) ions from sulphate medium

Abstract

This article introduces a novel approach for extracting and concentrating uranium (VI) ions from water-based solutions using two dithiocarbamate functionalised cross-linked polyacrylamide adsorbents, CPAAm-DETA-CS2 and CPAAm-EDA-CS2. The adsorbents were synthesised and characterised through techniques like Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and elemental analysis. The efficacy of these adsorbents in removing U(VI) species from solution matrices was systematically investigated, yielding maximum adsorption capacities of approximately 57.8 mg/g and 60.2 mg/g for CPAAm-EDA-CS2 and CPAAm-DETA-CS2, respectively. The optimised operational parameters encompassed a solution pH of 4.0, a contact period of 60 minutes, and an adsorbent dosage of 1.7 g/L, all conducted at ambient temperature. The adsorption adhered to the Langmuir isotherm and pseudo-second order kinetics, with a spontaneous and exothermic nature. Notably, the adsorbents displayed potential for regeneration and reuse. CPAAm-DETA-CS2 sorbent which exhibits the highest sorption capacity was applied successfully for the removal of uranium(VI) removal from sulphate leach liquor of Sella uranium ore. The adsorption capacity of the prepared sorbent was ≈ 45.3 mg/g. These aforementioned findings underscore the viability of a sustainable approach for uranium extraction, highlighting the notable importance of dithiocarbamate functionalised cross-linked polyacrylamide as a proficient adsorbent within the realm of environmental and industrial uranium separation processes.