Abstract
In this study, the sorption of Cu(II) ions from aqueous solution onto NaOH-treated kenaf core fibres was investigated. The kenaf core fibres were milled into different sizes and treated with NaOH before being used to investigate their efficiency in removing Cu(II) ions from aqueous solutions. Sorption studies were performed at a pH value of 5. Sorption of the Cu(II) ions increased and the sorption yield decreased with increasing initial Cu(II) ion concentration. The sorption data were correlated with the Langmuir, Freundlich and Dubinin–Radushkevich (D–R) isotherms. The values of the correlation coefficients obtained indicated that the Langmuir isotherm fitted the experimental data better than the Freundlich and D–R isotherms. Kenaf core fibres with fibre sizes in the range 150–300 μm possessed the highest sorption capacity. The calculated parameters of the isotherms suggest that the uptake of Cu(II) ions occurred at the homogeneous active sites on the surfaces of the kenaf core fibres.