Synthesis of nano crystallite cellulose and chitosan from waste natural source for the adsorption of cationic and anionic dyes in aqueous medium

Abstract

This research work narrates an economically friendly way to synthesize cellulose nanocrystal (CNC) and chitosan (CS) from waste jute bag and shrimp shell, respectively. Different analytical techniques such as X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and Scanning electron microscopy (SEM) were adopted to characterize diverse chemical and physical properties of the prepared samples, for the confirmation of the identity and assessment of the compatibility of the synthesized specimen for the targeted application. Crystallite size and crystallinity index were accounted for using XRD standard for CNC. The degree of deacetylation was also enumerated using chitosan's FT-IR record which was almost 98 %. The rest of this work is based on the hypothesis that, solely, an adsorbent exhibit either negative or positive net charge and shows affinity towards only oppositely charged dye molecules, while an appropriate hybrid blend of both negatively and positively charged adsorbent may show approximately equal affinity toward both anionic and cationic dye. Based on this concept, the potentiality of blending varying percentages of CNC and CS, as an adsorbent was monitored by executing the adsorption process considering different parameters like adsorbate interaction with adsorbent, pH, influence of initial concentration, contact time and dose of adsorbate with mostly found textile dyes Methylene blue (MB) and Congo red (CR) in wastewater which are cationic and anionic respectively. Cellulose nanocrystal and chitosan in the ratio of 50:50 showed an excellent result in the removal of both dye molecules.

Keywords

• Hydrolysis
• Deacetylation
• X-ray diffraction (XRD)
• Cationic dye
• Anionic dye