SYNTHESIS OF ZnAl-LDH/PVA NANOCOMPOSITE AND ADSORPTION OF PATENT BLUE V FOOD DYE FROM WATER SOLUTION

Abstract

In the presented research work, zinc and aluminum containing layered double hydroxides on the polyvinyl alcohol matrix (ZnAl LDH/PVA) were prepared by the co-formation technique and characterized by X-ray diffractometer, Brunauer-Emmett-Teller (BET) and Ultraviolet-visible (UV-Vis) spectroscopy. Both low and high pH is determined as optimal pH for Patent Blue V (PBV) adsorption on the ZnAl LDH/PVA nanocomposite and it is explained by the fact that the dye molecule is zwitterionic. Sorption of Patent Blue V food additive (E 131) on the obtained nanocomposite was studied by Temkin, Freundlich, Langmuir, and Dubinin-Radushkevich (D-R) isotherm models. Based on the obtained isotherm curves, the adsorption of PBV more closely matches Temkin model. The regenerated nanocomposite shows higher adsorption because the specific surface area increased from 5m2 g-1 to 8.94 m2 g-1 by BET analysis.