Extraction of Uranium (VI) with Triton X-100/Tween-40/D2EHPA/ BMIMMeSO4: Factorial Design Optimization from Cloud Point

This work reports the Uranyl (UO22+) extraction from water by the Triton X-100 / Tween-40 / D2EHPA / BMIMMeSO4 by two aqueous phases or Cloud Point Extraction (CPE). The procedure has been developed to extract uranium (VI) using a mixture of non-ionic surfactants: Triton X-100 and Tween-40 in different contexts, and a mixture of lipophilic chelating extracting agent D2EHPA/ BMIMMeSO4. The UO22+ sample was analyzed by UV-Visible spectroscopy. A mixture of 100 µL of Arsenazo III and 100 µL of UO22+ in a medium whose pH was equal to 2.0. The interaction product of Arsenazo III with UO22+ was determined at λmax= 653 nm. Three key variables: initial pH value, ion strength, and initial uranyl concentration have been studied by the 33 factorial design methods, in order to find the optimum conditions for uranium (VI) extraction. The temperature, the time, and the concentrations of Triton X-100 and Tween-40 were fixed: T =25°C, time = 24 hours, Triton X-100 (8%), and Tween-40 (2%). The optimal extraction of uranium (VI) by Micelle-Mediated Extraction (CPE) procedure was obtained for pH= 3.0, Na2SO4 (% w/w) = 9.0, and [UO22+] = 5.50 mM. This system has research value and application in wastewater treatment.