Efficient and ecological removal of anionic pollutants by cationic starch-clay bionanocomposites

摘要

The present work introduces the role of bio-hybrid materials based on the combination of cationic starch and clays belonging to the smectites family, in the removal of pollutants such as organic dyes and pesticides of anionic character. Two types of smectite clay minerals have been used as inorganic counterpart of the bionanocomposites: a purified bentonite from deposits in Maghnia, in the West of Algeria, and the commercial Cloisite® (Na-montmorillonite). In the first stage, potato starch was modified with glycidyltrimethylammonium chloride, and then incorporated to the clay by ion-exchange reaction at diverse biopolymer/clay ratio. These bionanocomposites were characterized by using various techniques: IR spectroscopy, XRD, TG-DTA and FE-SEM. The excess of cationic charge in these bionanocomposites results of great interest for their application in the removal of anionic pollutants, such as the anionic dye Congo Red and the 2,4-dichlorophenoxy acetic herbicide, from water solution. © 2013 by American Scientific Publishers.