ORANGE PEEL WASTES AS LOW-COST ADSORBENT FOR REMOVAL OF NICKEL AND CHROMIUM IN AQUEOUS SOLUTION

Abstract

Agricultural-by products such as orange peel (OP) was found to be abundant in quantity and had great components to adsorb the heavy metals. In this study, orange peel was used as biosorbent in adsorption process of heavy metal. The main aim of this study was carried out to examine the ability of adsorbents orange peel to remove nickel, Ni(II) and chromium, Cr(VI) ions from aqueous solution. From literature review, orange peel was proven can adsorb considerable quantities of Ni(II) and Cr(VI) ions in aqueous solution. The adsorption of Ni(II) and Cr(VI) ions were conducted in batch experiment to investigate the different parameters which are the effect of contact time, pH, adsorbent dosage and initial Ni(II) and Cr(VI) concentration. the optimum conditions for Cr(VI) were achieved when using 1.5 g of acid-treated orange peel at pH 3 in 20 ppm of initial Cr(VI) concentration which successfully removed 47.45% of Cr(VI) from aqueous solution within 90 min of contact time. The optimum conditions for Ni(II) were achieved when using 1.0 g acid-treated orange peels at pH 7, with 40 mg/L of initial Ni(II) concentration which removed 83.85% Ni (II) from aqueous solution within 90 min of adsorption time.  Statistical analysis showed that that there was a significant mean different between percent removal of heavy metal adsorb by raw and acid-treated corncobs. However, there is no significant relationship between dosage and percent removal of Cr(VI) from aqueous solution. Therefore, raw and acid-treated orange peel certainly can remove Ni(II) and Cr(VI) ions from aqueous solution.