Electrodeionization (EDI) Systems

Electrodeionization systems integrate ion exchange resins with electrodialysis technology to produce ultra-pure water continuously without chemical regeneration. The technology utilises direct current to drive ion migration through selective membranes while ion exchange resins provide additional purification and electrical conductivity. EDI modules contain alternating layers of cation and anion exchange membranes with mixed-bed resin compartments, creating dilute and concentrate chambers. As water passes through the dilute chambers, electrical current drives dissolved ions through selective membranes into concentrate chambers for removal. The continuous electrical regeneration of ion exchange resins eliminates the need for chemical regenerants, reducing operational costs and environmental impact. Systems typically achieve resistivity levels exceeding 10 megohm-cm with minimal variation, making them ideal for critical applications. Advanced control systems monitor conductivity, pH, and current density to optimise performance and detect potential issues. The technology operates best with RO permeate as feed water, further enhancing water quality while minimising energy consumption and operational complexity.