EN
Electroplating rinse solutions contain considerable amounts of multivalent valuable or toxic metal ions. The attempt to recover them was made using the Donnan dialysis (DD) technique, applying a cation-exchange polymer membrane. Laboratory experiments dealing with processing two different solutions containing Zn(ll) [A], or Zn(II), Cu(II), Ni (II), Cr(III) and Fe(III) [B] were carried out. The results demonstrated DD to be efficient for recovering Zn(II) (soln.A) and other multivalent metals (soln.B) in the sequence Ni, Cu>Fe>Zn>Cr. Recovery factors amount to 80-90% and 74-94% for A and B solutions, respectively. The optimum concentration of sulfuric acid in the strip solution ranges from 0.25 to 0.5 M.