Adsorption of Vanadium (IV) on the Synthesized D2EHPA-TBP Impregnated Resin
Solvent impregnated resins (SIRs) were synthesized by impregnating Amberlite XAD-16HP with the mixing extractants with (Di-(2-ethylhexyl)phosphoric acid (D2EHPA) to TBP (Tributyl phosphate) ratios of 1:0, 4:1, 1:1, 1:4 and 0:1. The adsorption capacity of D2EHPA-TBP impregnated resin (DTIR) for V(IV) decreases with the increasing content of TBP because TBP do not adsorb V(IV). However, TBP can allow D2EHPA to be distributed more homogenously and uniformly in the pores of SIR. Thus, the effective utilization rate of D2EHPA increases with the increasing TBP. Among the ratios of D2EHPA to TBP studied, 4:1 is the most appropriate one for preparing SIRs. The DTIR with D2EHPA to TBP ratio of 4:1 presents the highest separation factor of V(IV) to Fe(II) and V(IV) to Al(III) than other DTIRs. Moreover, TBP also can break the hydrogen bonds in the D2EHPA dimers and convert part of D2EHPA dimers to the monomers, which may accelerate the adsorption of V(IV) on the DTIR.