The adsorption of malachite green (MG) dye on mango leaf powder (MLP) was investigated in a batch process. The adsorbent prepared was characterized by Fourier Transform Infrared Spectroscopy. Operational parameters such as initial dye concentration, contact time and solution temperature governing the adsorption process were studied and evaluated. Equilibrium data were fitted to both Langmuir and Freundlich isotherm models, Langmuir model gave the best fit. The maximum monolayer coverage Q0 was 4.49 mg/g. Kinetic parameters, rate constants, equilibrium sorption capacities, and related correlation coefficients of pseudo-first-order and pseudo-second-order models were calculated and discussed; the pseudo second-order model provided the best correlation with R2 ≥ 0.99. Thermodynamic functions such as Standard free energy (ΔG0), standard enthalpy (ΔH0), and standard entropy (ΔS0) were also calculated. The adsorption process was found to be feasible, spontaneous and endothermic in nature.
Keywords: Mango leaf powder, Malachite green, Equilibrium, Adsorption, Thermodynamics