Synthesis and Characterization of Polymer Inclusion Membranes Containing Uranium-Selective Transporters

Environmental contamination has become more serious with the rapid development of modern industry, where many wastes have cruelly polluted the natural environment. Among these wastes, radioactive effluents generated during nuclear operations which vary in chemical composition and radionuclides. Uranium is among the most dangerous radionuclides present in the effluents generated by the activities of the Draria nuclear research center due to its chemical toxicity and radioactivity. For the protection of the environment and human health, the elimination of uranium is necessary. Several techniques have been used for this purpose: chemical precipitation, solvent extraction, ion exchange, adsorption and membrane processes. Membrane processes have been used for the recovery of many metals of strategic and economic interest such as uranium, copper, molybdenum, cadmium, lead and zinc, etc. Polymer inclusion membranes so-called membranes of third generation have the advantage of being selective because they incorporate specific extractants in their structure which gives them great stability. In the present study, we developed inclusion polymer membranes based on cellulose triacetate (TAC) containing 2-diethyl hexyl phosphoric acid (D2EHPA), Tributyl phosphate (TBP) at different volumes and the mixture of Tributyl phosphate and kerosene (TBP/kerosene) as carrier. The physicochemical and the structural characterization of the synthesized membranes are made by Fourier transform infrared (FTIR), by scanning electron microscopy (SEM) and by differential thermal analysis (ATG/ATD). The performance of these membranes toward uranium are studied by determining the number of fixed complexing sites on each type of membrane using UV-Visible spectrophometry for the determination of  the fixed uranium by the Arsenazo III method . The results of the comparative study of the performance of the different membranes developed showed that the most selective membrane for uranium is that containing tributyl phosphates alone as a carrier (TAC-NPOE-TBP)