In this diploma thesis the sorption of the copper ions from copper(II) nitrate trihydrate solutions on egg shells was studied. Different starting concentrations (3.8881 mmol dm-3, 7.780 mmol dm-3, 11.763 mmol dm-3, 19.305 mmol dm-3, 30.576 mmol dm-3 and 39.390 mmol dm-3) were used in a batch reactor under experimental conditions: temperature of 318 K, speed of 200 rpm and duration of 72 h. There is a slight increase in the amount of copper ions sorbed (qe) on egg shells with the increase of equilibrium concentrations of copper ions in solution (ce) up to a concentration of 11.763 mmol dm-3 and then there is a sudden increase of copper ions sorption observed for higher equilibrium concentrations of copper ions solutions. The obtained maximum sorption capacity of copper ions sorbed qe = 6.237 mmol g-1 equals the equilibrium sorption capacity of copper ions that can be sorbed on egg shells. The sorption efficiency of copper ions on egg shells increases with the increase of the initial concentration of copper ions in the solution and reaches its maximum value for the initial concentration of 30.576 mmol dm-3. The experimental data obtained were compared to Langmuir, Freundlich, Toth, Redlich-Peterson and Sips's adsorption model. There is a very poor consistency of the experimentally obtained data with selected adsorption models, which was confirmed by the extremely high values of the average absolute relative deviation (AARD) and low values obtained for the nonlinear correlation coefficient (r2). Since none of the selected isotherm models showed good agreement with the experimentally obtained data, it is not possible to ascertain the type of sorption.