This work concerns the extraction of U(VI) using supported liquid membrane (SLM) by di-(2-ethylhexyl) phosphoric acid (D2EHPA)
and tri-n-octyl phosphine oxide (TOPO) with polyvinylidene difluoride (PVDF) as a membrane support. The influence of ionic
strength (S), stirring rate (V) and extraction time (t) were studied. The effect of membrane thickness on the permeability and extraction yield of uranium was investigated. A comparative
study was carried out using a 23 full factorial design between SLMs with one membrane and two membranes, and to achieve the best conditions of recovery procedure,
obtaining the mutual interaction among variables and optimizing these variables. The recovery of U(VI) is almost quantitative,
and the supported liquid membrane with two membranes in series is effective.
A new sorbent, polyethyleniminemethylenephosphonamidic acid (PEIPPA), was synthesized from commercially available polyethylenimine
and P,P-dichlorophenylphosphine oxide. After characterization by (1H, 13C, 31P) NMR and FTIR, the new ion-exchange polymer has been investigated in liquid-solid extraction of uranium. The extraction
strongly depends on the pH, initial concentration of uranium, extractant to analyte ratio (mol/mol), ionic strength of the
liquid medium and their mutual interactions. Such interactions were investigated through factorial 33 experimental designs in order to achieve the best conditions of batch sorption procedure, obtaining the mutual interaction
among variables and optimizing these variables. The recovery of U(VI) is almost quantitative.