Abstract In this study, the locally available materials which include; montmorillonite clay and rice husks were used to synthesize montmorillonite-silica nanocomposite as adsorbent in removal of lead from aqueous solution. Fourier transform infra-red (FTIR), was used to characterize the adsorbent. Batch method of adsorption was employed in the study and parameters that influence the adsorption such as adsorbent dose, initial concentration and contact time have been studied. The optimum conditions of the study were found at the initial concentration 500 mg/L, adsorbent dosage (0.3g), contact time 40 (minutes) and constant stirring at 200 rpm. The experiments were carried out at the natural pH 5 ± 0.3 of the solution and room temperature (309 K). The results showed the maximum percentage of lead removal to be 99.99%. The equilibrium data for the adsorption was analyzed using both Langmuir and Freundlich isotherms models with R2 =0.9375 and R2=0.9275 respectively and both fitted the experimental data. The maximum adsorption capacity (qmax) using Langmuir isotherm was found to be 132.802mg/g. The kinetics study was carried out by employing pseudo-first order and pseudo-second order kinetics, the result of the kinetic studies showed that pseudo-second order kinetic model was found to correlate well to experimental data with R2=1. The results indicate that montmrillonite-silica nanocomposite is a cost effective adsorbent that can employ for the adsorption of Lead from aqueous solution.
Keywords Clay, Silica, Nanocomposite, Adsorption, Heavy metal.