Adsorptive sequestration of methylene blue in single and multicomponent systems: kinetics, isotherm and thermodynamic

Abstract

The surge in world population in conjunction with the fast fashion industry has created substantial increase in textile production leading to an enormous release of wastewater containing dyes into water bodies. In this study, the adsorption of methylene blue (MB) in single, binary and in ternary dye system comprising of methylene blue (MB), acid blue 161 (AB 161) and crystal violet (CV) onto formaldehyde-treated watermelon rind (FWMR) was investigated as a function of pH, contact time, temperature, dosage and initial dye concentration. The watermelon rind was characterized using Scanning electron microscope, Fourier transform infrared spectroscopy and pH point of zero charge. Batch adsorption experiments were carried out to investigate the isotherm, thermodynamics and kinetics of the adsorption processes. The adsorption process was described by Freundlich isotherm in single system, Langmuir isotherm in binary and ternary system. The change in entropy (ΔS) and heat of adsorption (ΔH) of dye species on FWMR in were 1.076 kj/mol and 26.162 kj/mol respectively.