Background: Di- (2-ethyhexyl phosphoric acid), commonly known as D2EHPA, is an
important extractant used for the recovery of Zn (II) from aqueous waste. The D2EHPA extractant
encapsulated polymeric beads (EEPBs) were synthesized and investigated for the sorption of Zn (II)
from aqueous medium.
Objective: Synthesis of D2EHPA impregnated polymeric beads for the extraction of Zinc from zincrich
Method: The beads were prepared by the phase inversion technique.
Results: The amount of Zn (II) extracted was found to increase with contact time, beads weight and
concentration of solution. The kinetics measurement showed that about 250 min of equilibration time
was enough to remove saturation amount of Zn (II) from the solution. The sorption kinetics data fitted
well in the pseudo second order model and sorption results were found to follow Langmuir sorption
isotherm model. Stripping investigations carried out using different stripping agents indicated that 2M
HCl is effective for stripping the Zn (II) loaded onto the synthesized beads.
Conclusion: The maximum experimental capacity of the D2EHPA encapsulated beads was found to
be 33.8 mg g-1 for Zn (II). The synthesized beads enabled the selective extraction of Zn (II) ions from a
simulated complex waste matrix with good recyclability upto the studied 4 sorption and desorption
cycles. The sorption capacity was found to be maximum at pH 5.0 and decreased significantly on
either side of pH 5.0. These synthesized sorbent beads can be selectively and efficiently employed for
the recovery of zinc from usual Zinc-rich waste liquor.