Surface adsorption of Pb ²⁺ ions from aqueous solutions using chitosan grafted with a mixture of IA-MAm / bentonite

ABSTRACT

Water pollution with heavy metal ions is unsafe for drinking due to the toxicity of these ions. For this reason, the methods of removing these ions are of particular importance.In this study, a new medium molecular weight chitosan substrate adsorbent was grafted with a mixture of Itaconic acid (IA) – Methacrylamide (MAm) and bentonite. The characterisation was performed by XRD, FTIR, TGA and SEM methods. Its efficiency in adsorption of pb²⁺ ions was investigated by batch technique. The parameters affecting the adsorption were optimised. The best conditions for the adsorption of lead ions (time = 60 minutes, pH = 4.0, adsorbent = 0.02 g, adsorbate concentration = 400 mg/L and q_max = 520 mg/g) were recorded. Adsorption data were also fitted by Temkin-Piozhov and Langmuir isotherms and a Pseudo-second-order kinetic model, as well. Thermodynamic parameters showed that the adsorption process is endothermic and spontaneous and is associated with increased entropy. The adsorbent efficiency in the removal of lead ions in industrial effluents was good.

KEYWORDS:

• Removal
• isotherm
• kinetics
• composite

Disclosure statement

No potential conflict of interest was reported by the author(s).