Methylene blue adsorption onto an eco-friendly modified polyacrylamide/graphite composites: Investigation of kinetics, equilibrium, and thermodynamic studies

Batch adsorption system using eco-friendly glucose and glucosamine grafted polyacrylamide/graphite composites were investigated to eliminate methylene blue (MB) dye from aqueous solution. The effect adsorption parameters reveal that pseudo-second order and Langmuir model exhibited good correlation with the adsorption kinetic and isotherm data for pollutant, respectively. Furthermore, an increase in pH from 2 to 11 was accompanied by an approximately fourfold increase in the amount of dye adsorbed. The maximum removal efficiency of MB was 96.23% under optimum conditions with equilibrium time of 40 min. The thermodynamic data supported its spontaneous and endothermic property of adsorption process. A possible adsorption mechanism has been proposed, where H-bonding and electrostatic interactions dominated the adsorption of dye.