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

Abstract

The removal of heavy metal ions Cr (VI) and Zn (II) from aqueous solution using the
skin of orange peel (Citrus sinensis) as an adsorbent under different experimental
conditions was investigated in this study. The concentrations of the metal ions adsorbed
were determined by atomic absorption spectroscopic (AAS) method. The parameters
investigated were temperature, contact time, adsorbent dosage, initial metal ions
concentration and pH. It was observed that the white inner skin of orange removed more of
Cr (VI) than Zn (II) metal ions in all the adsorption experiments. The optimum removal of
the Cr (VI) and Zn (II) metal ions occurred at pH 3 and at temperature 30°C. Application of
the 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; Langmuir

DOI: 10.3126/jncs.v26i0.3628

Journal of Nepal Chemical Society
Vol. 26, 2010
Page:31-39