Removal of copper ions from electroplating wastewater by ion exchange in a liquid-solid semifluidized bed is-studied. The column diameter and height of the semifluidized bed is studied. The column diameter and height of the semifluidized bed are 8.1 and 150 cm, respectively. CuSO4 solution is used as the synthetic wastewater, and Amberlite 200C resins are employed as the ion-exchange resins. It is found that the effluent Cu2+ concentration of the semifluidized bed increases as the liquid volumetric flow rate or feed concentration is increased. Moreover, the height of the fluidized bed section keeps decreasing during the ion-exchange process. A mathematical model is developed to describe the ion-exchange process in the semifluidized bed satisfactorily. A comparison of the performance of the semifluidized bed, the fluidized bed, and the packed bed based on the treatment efficiency is also made. It shows that the treatment efficiency is the highest for the semifluidized bed.