The sorption of Cu2+ ions from aqueous solutions by eggshell was investigated in a batch experimental system with respect to the temperature, initial Cu2+. concentrations, pH, and biosorbent doses. The adsorption equilibrium was well described by the Langmuir isotherm model with the maximum adsorption capacity of 5.05 mg Cu2+/g eggshell at 25 degrees C. The value of q(e) increased with increasing the temperature while also increases the release of Ca2+ and HCO3-, ions from the eggshell. The highest sorption of Cu2+ onto the waste eggshell was determined at the initial pH value of 4.0. The results confirming that the adsorption reaction of Cu2+ on the eggshell was thought to be endothermic. A comparison of the kinetic models such as pseudo first and second-order kinetics, intrapartide diffusion, and Elovich on the sorption rate demonstrated that the system was best described by the pseudo second-order kinetic model.