<p>The treatment of spent chromic acid baths before disposal is both complicated and costly due to their significant concentrations of heavy metals. It is often difficult to implement multi-step processes on a large scale for conventional purification of industrial effluents. This study focused on developing a hybrid electrodialysis–ion exchange (ED–IE) system that can improve the purity efficiency of chromic acid bath effluents that contain metallic impurities. A comparison was made between conventional electrodialysis (ED) and a three-compartment ED–IE configuration for removing metallic cations in an acidic environment. Results demonstrated that the hybrid ED–IE system, operating in a three-compartment configuration that allows the solution to pass through the cell only once, achieved faster, and more efficient metal removal than standalone ED. Specifically, the removal rates increased from 43.13% to 50.94% for Cu²⁺, from 45.79% to 53.50% for Zn²⁺, and from 29.90% to 46.50% for Fe³⁺. The evaluation of key operating parameters revealed that higher current density and pH significantly enhanced purification performance, while higher solution flow rates negatively impacted removal efficiency. Furthermore, the use of a five-compartment ED–IE system in a double-pass configuration further improved removal rates, achieving 65.54% for Cu²⁺, 67.32% for Zn²⁺, and 64.25% for Fe³⁺. These findings highlight the potential of the hybrid ED–IE technology as an efficient and scalable solution for the treatment of spent chromic acid baths. In addition to enabling bath regeneration and promoting their reuse in industrial applications, this process also eliminates sludge generation, commonly associated with conventional treatments, thereby contributing to cleaner, more sustainable surface treatment practices.</p>