Removal and characterisation of Pb(II) ions by xylenol orange-loaded chitosan: equilibrium studies.

In this study chitosan (CS) was modified by coating with xylenol orange (XO). The batch adsorption of Pb(II) ions on modified chitosan (CS/XO) was investigated. The modification of chitosan was confirmed by FT-IR spectroscopy, scanning electron microscopy (SEM) and x-ray diffraction (XRD). The adsorption behaviour of the modified chitosan against Pb(II) ions were evaluated. Among these, pH effect, adsorbent dosage and initial concentration of Pb(II) ions. The results showed that the modified chitosan possesses good capacity for lead ions. The modified surface exhibited an affinity to chelating lead ions in solution, forming complex. The experimental results were examined by the Langmuir and Freundlich isotherm models. The maximum adsorption capacities of Pb(II) ions based on the Langmuir isotherm model were 0.457 mg/g. [ABSTRACT FROM AUTHOR]