Extraction of Bi(III) from nitrate medium by D2EHPA impregnated onto Amberlite XAD-1180

Di(2-ethylhexyl)phosphoric acid (D2EHPA) was fixed on the Amberlite XAD-1180 solid support by extractant impregnated resin technique (EIR). The quantity of the adsorbed extractant in the resin was in function of the polarity of the impregnation solvent. Thus, the optimal loading of the monomeric D2EHPA was 6 g/g of dry resin using acetone as solvent. The kinetics measurements on the extraction of bismuth (III) ions from nitrate aqueous solution were conducted while varying the initial pH of aqueous solution, initial bismuth concentration, D2EHPA content in the Amberlite XAD-1180 resin, stirring speed and equilibrium time. The extraction yield of bismuth was determined at 98.5% equivalent to 490.7 mg of Bi/g of resin, so the D2EHPA–Bi complex was suggested. Also, the complete regeneration of resin was realized in two stages in the presence of concentrate hydrochloric acid. The increase of the immersion aqueous volume, slightly decreases the sorption of Bi(III). The antagonistic effect on the sorption of Bi(III) was observed by adding sodium chloride. 33 factorial designs were employed for screening the factors that would influence the overall optimization of a batch procedure of sorption.