Biodegradable glucose and glucosamine grafted polyacrylamide/graphite composites for the removal of acid violet 17 from an aqueous solution

Abstract

Abstract In this work, the structural characterization and adsorption behavior of glucose and glucosamine grafted polyacrylamide/graphite composites (denoted as Gu-g-PAM/graphite and GA-g-PAM/graphite) were investigated. The grafted polymers were characterized by using Fourier transform infrared (FT-IR) spectroscopy, 1H nuclear magnetic resonance (NMR), 13C NMR and N2 sorption studies. The adsorption behavior of grafted polymers was compared by varying parameters such as pH, initial dye concentration, agitation time, adsorbent dose and temperature. The results showed that GA-g-PAM/graphite composite was an effective adsorbent for the uptake of acid violet 17 (Av-17) from an aqueous solution. The superior adsorption behavior was attributed to the presence of -NH2 and -OH groups in GA-g-PAM/graphite. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherms were used to describe the adsorption isotherm. The adsorption isotherm of the adsorbents fitted well with the Langmuir model with the maximum adsorption capacity (qo) of 78.13 mg/g for GA-g-PAM/graphite. The efficiency of adsorption with time was described using pseudo first-order, pseudo second-order and intra particle diffusion kinetic models. The kinetic study revealed that the adsorption equilibrium was attained within 50 min. The thermodynamic analysis stated that the adsorption of dye is spontaneous, physical and endothermic in nature. Desorption results revealed that all the adsorbents exhibit excellent stability and remarkable regeneration ability.