Nanocrystalline cellulose from waste paper: Adsorbent for azo dyes removal

The preparation of nanocrystalline cellulose from waste printed papers as adsorbent was conducted using organic solvent. The synthesize of nanocrystalline cellulose is characterized by Fourier transform-infra red (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Hydroxynaphtol blue and congo red in aqueous solutions are used as sorbate in this study to test the single system adsorption capacity of nanocrystalline cellulose using Langmuir and Freundlich isotherm models at 30, 40, and 50 °C. Kinetic study are quantified using pseudo-first order and pesudo-second order models. The adsorption of both azo dyes resulted in negative value of ΔG° which shows spontaneous adsorption of both azo dyes onto adsorbent active sites. Higher temperature increase the adsorption of dyes represents the endothermic nature of adsorption and randomness of adsorbent-solution interface