Electrodeionization (EDI) For Industrial Use
For many years, operators of pure water production systems were trying to find a technology to replace mixed bed ion exchange for final demineralization. The operating cost as well as the complexity and risks associated with acid and caustic regeneration were frustrations to these operators. EDI became established as the innovative alternative solution by reducing operating costs, improving site environmental, health, and safety risk profiles, and producing a continuous and steady supply of pure and ultrapure water
EDI utilizes both traditional ion exchange resin and ion exchange membrane to remove contaminants, including those that are uncharged or lightly charged in the feed water such as silica and boron. The biggest advantage lies in the fact that EDI technology employs direct current to drive contaminants out of the feed water and through the ion exchange membranes into the concentrate channels. The direct current also splits water into hydrogen and hydroxyl ions which act as continuous regenerating agents so that contaminants do not accumulate on the ion exchange resin. Therefore, EDI can continuously and predictably produce high-purity and ultrapure water with equal or better quality than mixed bed ion exchange.
Advantages Of EDI Compared To Mixed Bed
• More advanced technology
• No regeneration chemicals or neutralization systems needed
• Much lower operating cost
• Continuous and simplified operation
• A smaller footprint and reduced building height requirement
Typical EDI Applications
• Semiconductor, microelectronic and solar panel production rinse water
• Boiler feed water for power generation or the chemical, steel, and metallurgical industries
• Various pharmaceutical industry waters • Laboratory water
