Preparation and Characterization of Polyamidoxime Chelating Resin from Rubberwood Fibre-G-Polyacrylonitrile

Abstract

Grafted rubberwood fibre was converted to polyamidoxime ion-exchange resin in order to remove heavy metal ions from aqueous solution. The cation-exchange resin existed predominantly in the syn -hydroxyamino form. The water uptake by the resin was ca. 31 g/g dry resin while its hydrogen ion capacity was 3.6 mmol/g. The adsorption capacity of the resin towards different metal ions from wastewater was determined at different pH values within the range 1–6. The prepared chelating ion-exchanger exhibited the highest adsorption capacity towards Cu 2+ ions (3.83 mmol/g), followed by Cd 2+ , Fe 3+ , Pb 2+ , Ni 2+ and Co 3+ ions, respectively. The results showed that the adsorption capacity depended on the solution pH. Polyamidoxime ion-exchange resin was also used to separate Co 3+ and Ni 2+ ions from Cu 2+ ions using a column technique. On passing Cu 2+ /Ni 2+ and Cu 2+ /Co 3+ ion mixtures through the resin at pH 3, Cu 2+ ions were adsorbed by the resin but no sorption of Ni 2+ or Co 3+ ions was detected. Approximately 98% of the Cu 2+ ions could be desorbed from the resin. FT-IR spectroscopy was used to confirm the conversion of polyacrylonitrile-g-rubberwood fibre to polyamidoxime.