Biopolymer Based Nanomaterials as Potential Biosorbents for Lead Ions

Abstract

The objectives of the present work included synthesis of nanoparticles of calcium crosslinked alginate by emulsion crosslinking method and their characterization by techniques such as FTIR, TEM and XRD. In order to study the effect of various factors like adsorbent dose, initial metal ion concentration, pH and temperature on the removal of lead ions from water using nanoparticles of alginate, a series of batch sorption experiments were conducted. The obtained results were analyzed by Langmuir and Freundlich isotherm models and it was found that the adsorption of lead more precisely follows Freundlich adsorption isotherm. The results were also analyzed through various kinetic models like Lagergreen pseudo-first order kinetics, the pseudo-second order kinetics, and intraparticle diffusion model. Adsorption of Pb ions from aqueous solutions was found to be best described by pseudo second order Lagergreen equation. It was also found that intra particle transport was not the rate limiting step. The removal of Pb ions was found to be more than 90 percent. The metal ion removal capacity of the nanoparticles was found to depend on the chemical composition of the adsorbent, concentration of the metal ion solution, pH and temperature of the medium and speed of the suspension.

Keywords: lead, alginate, nanoparticles, adsorption, emulsion cross linking.