A generic design procedure for the continuous ion exchange process is proposed. The procedure is based on the optimized arrangement of parallel batch columns. The continuity of the process is achieved by proper shifting of the inlet conditions. The method for the optimization of the process variables is presented. The concept is demonstrated on the example of ammonia removal from wastewaters. Two flowsheet schemes are considered utilizing fresh or recycled regenerating agent. The superiority of the optimized process over the periodic operation is demonstrated. (C) 2011 Elsevier Ltd. All rights reserved.