Performance of aquatic weed - Waste Myriophyllum spicatum immobilized in alginate beads for the removal of Pb(II)

Abstract

A new biosorbent - alginate encapsulated with Myriophyllum spicatum - MsA was investigated for lead ions removal. This biosorbent was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), zeta potential, X ray Diffraction (XRD) and size distribution analysis. FT-IR analysis demonstrated that the lead ions sequestration mechanism included ion exchange and lead complexation with the carboxyl, carbonyl and hydroxyl groups in MsA. In order to better understand the mechanisms of the binding of Pb(II) on immobilized M. spicatum beads, 3 reaction and one diffusion based kinetic models were applied on kinetic data removal lead ions on three materials: M. spicatum, Ca-alginate and MsA. Myriophyllum spicatum encapsulated with alginate - MsA have higher adsorption capacity than M. spicatum. Among examined six isotherms Redlich-Peterson and the Langmuir isotherm model exhibited the best fit to the experimental data, with capacities ranging from 230 to 268.7 mg/g. Among the various tested desorption agents, nitric acid has proven to be the best. The obtained results suggest that the immobilized M. spicatum biosorbent holds great potential for lead wastewater treatment applications.