Preparation of Cellulose-Activated Carbon Gel with High Activated Carbon Content and Its Adsorption of Methylene Blue

Activated carbon is a useful adsorbent for the removal of pollutants from the aqueous phase. In this study, an easy method to overcome the difficulty in separating activated carbon from a solution after adsorption has been developed. Cellulose-activated carbon gels with a high activated carbon content up to 70% in the total solids were successfully prepared via the dissolution–regeneration process of cellulose using a LiBr aqueous solution. Activated carbon suspended in a cellulose solution dissolved by heating with a LiBr aqueous solution was embedded into a gel directly formed by lowering the temperature of the cellulose solution. The cellulose-activated carbon gels exhibited large specific surface areas and sufficient mechanical properties. The adsorption capacity of methylene blue onto the cellulose-activated carbon gels proportionally increased with the increasing content of activated carbon. The cellulose-activated carbon gels maintained a high adsorption capacity even after repeated adsorption–desorption cycles, demonstrating their potential as reusable adsorbents.