Capacitive deionization (CDI) is an emerging water treatment method that shows great promise for effi cient desalination

purposes. It enables the production of purifi ed, potable water by eff ectively removing ions from seawater and brackish water.

In this study, a unique capacitive deionization (CDI) cell design with an expansion part and without a spacer was proposed.

It was then optimized using computational fl uid dynamics (CFD) with ANSYS 21 (academic version) software to ensure a

uniform fl ow distribution across the electrode surface, thus maximizing the utilization of the electrode. Subsequently, the

developed optimum CDI cell was fabricated using 3D printing, and its desalination performance was evaluated in a batch

system using NaCl solution. The optimum CDI cell design enhanced the salt adsorption capacity of the process by 47% compared

to the fi rst proposed design. The eff ect of operating parameters like potential, fl ow rate, and time on the salt adsorption

capacity were investigated with the optimum CDI cell design. The maximum salt adsorption capacities were approximately

2.9 mg/g, 6.0 mg/g, and 14.7 mg/g for 2 mM, 20 mM, and 200 mM NaCl concentrations, respectively, at a potential of 1.2 V,

a fl ow rate of 20 mL/min, and an adsorption/desorption period of 15 min. The electrodes exhibited a stable performance and

full regeneration over long adsorption/desorption cycles. The fi ndings of this study highlight the eff ectiveness of the proposed

CDI cell design in enhancing salt removal effi ciency. These results contribute to the advancement of water treatment

technologies by providing insights into optimizing CDI processes for more effi cient and sustainable desalination operations.