Low Cost Biopolymer Adsorbents for the Removal of Heavy Metal Contaminant from Wastewater

Polymeric materials have been remarkably associated with our daily life. The hydrophilic/hydrophobic biopolymer systems have gained importance in the last few years, because of the environmental pollution of nonbiodegradable synthetic plastics. Recently, biopolymers with functional groups have been directly used for the fabrication of adsorptive membranes in order to avoid the undesirable morphology change of the membranes during the surface modifications. Compared with other modification technologies or a synthesis of totally new materials, biopolymer blending has several advantages like simplicity, reproducibility, and commercial feasibility. The valuable part of blending of biopolymers can be used for the preparation of new materials with improved physicochemical and mechanical properties. The objective of this work is the development of biomembranes based on a mixture of three biopolymers, that is, alginate (AL), chitosan (CS), and polylactic acid (PLA). Physical characterizations of the elaborated biopolymeric membranes are carried out by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and contact angle measurements. The SEM results show that the synthesized membranes exhibited homogeneous dense microstructures. The second objective of this paper is to evaluate the importance of these biopolymers in removing lead which is considered as toxic metal. In fact, all synthesized membranes are applied to the treatment of wastewater to eliminate heavy metals principally Pb2+.