Nonlinear and linear analysis of Direct Yellow 50 adsorption onto modified graphene oxide: kinetic, isotherm, and thermodynamic studies
Avideh Azizi, Elham Moniri, Amir Hessam Hassani, Homayon Ahmad Panahi, Mohamadreza Jafarinezhad
Abstract
ABSTRACT The present work describes the removal of Direct Yellow 50 from an aqueous solution by graphene oxide modified with 4-aminodiphenylamine (GO-A). The final adsorbent was characterized by carbon, hydrogen, and nitrogen analysis, Brunauer–Emmett–Teller technique, Fourier transform– infrared resonance spectroscopy, and scanning electron microscopy. Batch studies were carried out to investigate the effect of experimental factors such as contact time (5–120 min), initial dye concentration (10–80 mg/L), and temperature (25°C, 35°C, and 45°C) on the GO-A adsorption of dye. The linear and non-linear forms of kinetic and isotherm models were also investigated. The isotherm and kinetic data of dye were correlated reasonably well by non-linear Freundlich and Elovich models, respectively. The thermodynamic studies showed that the dye adsorption onto GO-A is a spontaneous, favorable, and exothermic process. Additionally, dye isotherm studies revealed that maximum dye adsorption capacities of 10.71, 8.03, and 5.71 mg/g were achieved for 25°C, 35°C, and 45°C temperatures, respectively. It can be collected that GO-A could be applied as an effective adsorbent for the removal of dye.