Abstarct: Abstract In this study, the "Elaegnus Angustifolia" and the " Salsola Oppositifolia" plant were used as cheap and available agricultural waste to remove colored pollutants from wastewater. After modification with sodium hydroxide solution, both adsorbents were analyzed and characterized by FT-IR (Fourier Transform Infrared Spectroscopy), Scanning Electron Microscope (SEM) and EDX techniques. In the next step, the efficiency of both modified adsorbents for the simultaneous removal of methylene blue and crystal violet dyes from aqueous solutions was investigated. The effect of laboratory parameters such as initial pH, initial concentration of dyes, adsorbent dose, contact time, temperature and ionic strength on the removal efficiency in single solutions and binary mixtures prepared from the mentioned dyes were investigated. The results determined the optimal conditions as pH=7, concentration of 30 mg/liter, absorbent amount of 0.02 g for elaegnus and 0.025 g for salsola at ambient temperature. The analysis of dye absorption data by Elaegnus Angustifolia showed that the Langmuir isotherm in the single-component system and the Freundlich isotherm in the two-component system can satisfactorily explain the equilibrium data. Using the Langmuir model, the maximum absorption capacity of 102 mg/g for methylene blue and 126 mg/g for crystal violet was calculated. The Freundlich model was used to describe the salt stem equilibrium data in the single-component system, and the Langmuir model was used for the methylene blue dye in the two-component system, and the Freundlich model was used for the crystal violet dye. The maximum absorption capacity of 33.8 mg/g was calculated for the Salsola Oppositifolia adsorbent..Kinetic studies also showed that the absorption process of both dyes follow the pseudo-second-order kinetic model. Thermodynamic parameters were also determined, which confirmed the spontaneity of the surface adsorption process due to the negative value of ∆G°. The positivity of ∆H° and ∆S° respectively indicated the endothermic nature of the surface absorption process and the increase of irregularity in the interface between the absorbent and the absorbent material. It should be noted that both absorbents were recovered and reused using ethanolic soda and dishwashing liquid.