Sorption of malachite green and Rhodamine-B dyes from aqueous solution by biomass waste: Kinetics, isotherm and thermodynamic studies

A biomass waste has been evaluated without chemical modification as low-cost effective adsorbent to remove Malachite Green (MG) and Rhodamine-B (RhB) dye srespectively from aqueous solution in batch experiment. The effect of certain parameters on the adsorption capacity has been investigated such as particle size, contact time, initial dye concentration, pH, mass of the adsorbent and the effect of temperature. Isotherms study has been described by the Freundlich model which indicates that MG and Rh-B sorption process onto biomass is more described by good correlation coefficients (R-2=0.867 and 0.953, respectively). Kinetic study shows that MG and Rh-B adsorption process follow pseudo-second order kinetics model. Furthermore, thermodynamic parameters reveal that the adsorption is spontaneous and endothermic.