TEMPO-oxidized Cellulose Nanofibers/ Alginate Nanocomposite as a Promising nanocomposite Material for the Adsorption of Cationic Dyes

TEMPO-oxidized cellulose nanofiber/alginate nanocomposite (T-CNF/SA) was prepared and characterized as a recyclable adsorbent for cationic dye. TEMPO-oxidized CNFs contain a large number of carboxylic groups, they may interact with methylene blue as a model of cationic dye in aqueous solutions. Two materials were synthesized in this study: T-CNF and CNF/SA nanocomposite. In order to determine the ability of the nanocomposite to remove the dye, batch sorption experiments were performed using the nanocomposite after their synthesis and characterization. In the studied concentration range of dye, equilibrium data were well fitted to the Langmuir isotherm model, indicating that dye removal is a favorable process. At 25 °C and neutral pH, the maximum adsorption capacities reached 185.2 mg dye/g and 216.4 mg dye/g for T-CNF and for T-CNF/SA, respectively. The adsorption efficiency was up to 95% after 2 h for T-CNF/SA. The adsorption data fitted well with the second-order kinetic model high correlation coefficients (R2> 0.99) and the isotherm data followed the Langmuir model equation. Finally, the study presents a feasible, practical, and reusable nanocomposite as an interesting adsorbent for wastewater treatment.