Adsorption of Chromium(VI) and Zinc(II) Ions on the Skin of Orange Peels ( Citrus sinensis)

Abstract

The removal of heavy metal ions Cr (VI) and Zn (II) from aqueous solution using theskin of orange peel (Citrus sinensis) as an adsorbent under different experimentalconditions was investigated in this study. The concentrations of the metal ions adsorbedwere determined by atomic absorption spectroscopic (AAS) method. The parametersinvestigated were temperature, contact time, adsorbent dosage, initial metal ionsconcentration and pH. It was observed that the white inner skin of orange removed more ofCr (VI) than Zn (II) metal ions in all the adsorption experiments. The optimum removal ofthe Cr (VI) and Zn (II) metal ions occurred at pH 3 and at temperature 30°C. Application ofthe Langmuir isotherm to the systems yielded maximum adsorption capacity of 8.068 (mg/g)and 1.078 (mg/g) for Cr (VI) and Zn (II) metal ions respectively.Keywords: Orange peel; Adsorption; Heavy metals; LangmuirDOI: 10.3126/jncs.v26i0.3628Journal of Nepal Chemical SocietyVol. 26, 2010Page:31-39