USE AQUEOUS PEG-INORGANIC SALT TWO-PHASE SYSTEMSFOR Bi(III) EXTRACTION IN THE PRESENCE OFINORGANIC EXTRACTANTS

摘要

The Bi(III) extraction behaviour was studied in aqueous polyethylene glycol (PEG) – (NH_4)_26O_4 two-phase system, using inorganic anions (I,Br,CI and SCN), as extractants. The aqueous two-phase systems were prepared using aqueous solutions of phase-forming components (PEG and (NH_4)_2SO_4) in water or in 1N H_2SO_4. The experimental results show that more adequate for Bi(III) extraction is the aqueous two-phase systems, where the aqueous solutions of phase-forming components are prepared in 1N H_2SO_4. Under these conditions, the addition of inorganic extractants determined the partitioning of Bi(III) into PEG-rich phase, easy observable at extractants concentration higher than 0.06 mol/dm~3. The efficiency of extractants follows the order: Br > Cl SCN. Using the Bi(III) distribution coefficients calculated as a function of inorganic extractants concentration, the extracted species were assumed.