Adsorption of crystal violet using a composite based on graphene Oxide-ED@Cellulose: Adsorption modeling, optimization and recycling

Abstract

The current work, provides the results of a study related to the synthesis of composite based on ethylene diamine modified reduced graphene oxide and cellulose (rGO-ED@Cellulose) to improve the dispersion of GO sheets. After improving its properties, the composite was employed for the adsorption of crystal violet, a cationic dye. Point zero charge (pHPZC) was used to characterize the composite, in addition to other methods including X-ray diffraction, scanning electron microscopy, and energy dispersion X-ray spectroscopy (FTIR, XRD, and SEM/EDS). Studies on batch adsorption were conducted with operational parameters such as contact time, dosage of the adsorbent, concentration of the dye, pH, and temperature. The optimal parameters found were t = 80 min, 10 ppm, pH = 6, m = 0.1 g and T = 25 °C, this resulted in a capacity of adsorption of crystal violet value of 260 mg. g−1 and an adsorption efficiency of 88 %. The kinetic study showed that the adsorption of the cationic CV dye on the composite follows a pseudo 2nd order model kinetic. The Langmuir model was found to be a good fit for the isothermal data of the crystal violet adsorption by the composite study and the adsorption process is exothermic. A statistical model was used to assess the efficacy of CV adsorption on rGO-ED@Cellulose composite surface locations. The evaluation was carried out in a practical setting, utilizing a three-level Response Surface Methodology (RSM) based on Box-Behnken Design and the Expert Design software package.