Abstract
The adsorption of crystal violet (CV) onto date palm fibers (DPFs) was examined in aqueous solution at 25 degrees C. The experimental maximum adsorption capacity value was 0.66 x 10(-6). Langmuir, Freundlich, Elovich and Temkin models were applied to describe the equilibrium isotherms. The influence of pH and temperature on dye removal was evaluated. The percentage removal of CV dye by adsorption onto DPF at different pH and temperatures showed that these factors play a role in the adsorption process. Thermodynamic analysis was performed, and the Gibbs free energy Delta G degrees, enthalpy change Delta H degrees, and entropy Delta S degrees were calculated. The negative values of Delta G degrees indicate spontaneous adsorption. The negative value of Delta H degrees indicates that the interaction between CV and DPF is exothermic, and the positive value of Delta S degrees indicates good affinity between DPF and CV. The kinetic data were fitted to a pseudo-second-order model.