This study investigates the impact of chemical and thermal activation on the sorption capacity of Transcarpathian clinoptilolite from the Sokyrnytsky deposit. The chemical activation of natural clinoptilolite was performed using aqueous solutions of 5% HCl and 25% H 2 SO 4 at a solid-to-liquid phase ratio of 1:10. Thermal activation was conducted at a temperature of 300°C. The sorption capacity of both natural and activated clinoptilolite was evaluated for water vapor in this thermal analysis. The ability of activated clinoptilolite to absorb direct blue dye was determined through spectrophotometric analysis. The partial degradation of clinoptilolite due to acid modification was confirmed by X-ray phase analysis and electron microscopy. The sorption isotherms of direct blue dye were modeled using the Langmuir equation, and the corresponding constants were determined. Clinoptilolite activated with a 25% aqueous H 2 SO 4 solution is recommended for use in sorption technologies for wastewater treatment from direct dyes.