Carboxymethyl cellulose/carboxylated graphene oxide composite microbeads for efficient adsorption of cationic methylene blue dye

Abstract

An efficient composite adsorbent was fabricated based on carboxymethyl cellulose (CMC) microbeads incorporated carboxylated graphene oxide (GOCOOH) for the adsorptive removal of cationic methylene blue dye (MB). The developed CMC/GOCOOH composite microbeads were characterized by means of FTIR, TGA, SEM, XPS, BET and zeta potential analysis tools. Various parameters affecting the removal of MB dye such as the amount of GOCOOH, initial MB concentration, adsorbent dosage, pH and medium temperature were optimized using a series of batch adsorption experiments. The experimental data of the adsorption process were more fitted to Langmuir isotherm (R² = 0.998) with a maximum adsorption capacity of 180.32 mg/g and followed the pseudo-second order kinetic model. Moreover, the adsorption of MB dye onto CMC/GOCOOH composite microbeads was an exothermic process with a maximum capacity at pH 10. Besides, the fabricated adsorbent exposed also better reusability for nine repetitive cycles with highly adsorption properties. The gained results imply that the CMC/GOCOOH microbeads could be potentially applied as an effective and reusable adsorbent for MB dye removal from aqueous solutions.

Keywords: Carboxylated graphene oxide; Carboxymethyl cellulose; Methylene blue, adsorption; Microbeads; Reusability.