<p>This study includes the removal of crystal violet dye from its aqueous solution using activated carbon synthesized from the impregnation of fig leaves in zinc chloride solution. Before starting the practical experiments, different proportions of zinc chloride to fig leaves were tested, and then it was found that the mass ratio of 3:2 (FL-ZnCl₂) was the best in terms of removal % and adsorption capacity. The carbonization temperature was also tested on fig leaves at different values (250, 350, and 450&#xa0;°C), and 250 °C exhibited excellent results compared to other temperatures. The initial concentrations of the dye, the time required for adsorption, the acidic effect of the solution, the temperature, the volume of the solution, and the amount of the substance that performs the adsorption were the most important factors in the present study. Two widely used non-linear models—the Langmuir and Freundlich isotherms—were employed in this study to analyze the experimental data following the adsorption of crystal violet dye. The maximum adsorption capacity was 51.35 mg/g. The non-linear pseudo-first order and pseudo-second order models proved to be more suitable for describing the adsorption process, showing an excellent coefficient of determination (R² &gt; 0.99). The standard enthalpy change (∆H° = 26.95 kJ/mol), calculated using the Van’t Hoff equation, indicated that the adsorption process was endothermic. The adsorption of crystal violet dye onto FLAC-ZnCl₂ was found to be spontaneous, as shown by negative values of standard Gibbs free energy (∆G°), which ranged from –7.31 to –4.13 kJ/mol. It could be concluded that the novel adsorbent has great efficiency in removing dyes from aqueous solution. Reusability studies were conducted using the column-bed method with 0.2 g of FLAC, dilute acetic acid, and a 20 mg/L CV solution. The results demonstrated that FLAC could be used for up to five cycles for CV dye removal.</p>