EFFICIENT RECOVERY OF NICKEL (II) FROM A MIXTURE OF NICKEL (II) AND CHROMUIM (VI) IONS USING DUOLITE A7 RESIN

Abstract

Separation of Ni(II) and Cr(VI) from a solution containing a mixture of both ions was conducted using adsorption technique with Duolite A7 resin as the adsorbent. The effects of ionic strength (1.0 - 5.0 M), resin dosage (1.0 - 5.0 g), temperature (30 - 50°C) and equilibration time (5 - 150 mins) on the separation of both ions were investigated. Up to 91% adsorption of Ni(II) by the resin was observed at pH 4.5. It was observed that Ni(II) ion under each of the conditions showed significantly higher binding affinity to the resin than Cr(VI). Adsorption of Ni(II) was rapid and was completed in about 10 min equilibration time. There was a continuous decrease in the adsorption of both ions as the temperature of the mixture increased. The FTIR spectra of the unloaded and loaded resinshowed that Duolite A7 is highly selective for the optimum recovery of Ni(II) from a solution containing a mixture of Ni(II) and Cr(VI) ions under the considered experimental conditions.