Development of new organic-inorganic, hybrid bionanocomposite from cellulose nanowhisker and Mg/Al-CO3-LDHfor enhanced dye removal.

Abstract

The utilization of nanocomposite hydrogels in wastewater treatment has become one of the most important and remarkable issues in recent years. In this research project regarding to the importance of nanomaterials and bio-polymers, we tried to design and construct a new organic-inorganic hybrid nanomaterials with enhanced dye removal efficiency containing cellulose nanowhiskers and Mg/Al-CO3 layered double hydroxide (LDH) as organic and inorganic nanoscale materials, respectively. For this purpose, cellulose nanoparticles fabricated and modified through free radical graft polymerization of acrylic acid in presence of as prepared Mg/Al-CO3-LDH. The successful preparation of the product was evaluated using FT-IR, UV-vis, TGA, SEM, BET and XRD techniques. Also, the applicability of the prepared nanocomposite hydrogel (cellulose nanowhisker-graft-PAA/LDH) for removal of several cationic dyes was investigated. Kinetics study showed that adsorption onto the nanocomposite hydrogel was fitted into second order model for all of the dyes. The maximum adsorption capacity of nanocomposite hydrogel for cationic dyes were in range of 21-27 mg g-1 that showed significant improvement in comparison with the cellulose nanowhisker-graft-PAA hydrogel. For example, the percentage of dye removal increased from 33% by hydrogel to about 96% by nanocomposite hydrogel for Fuchsine. Furthermore, the hydrogel applied several times and showed stable performance after three adsorption-description cycles.