In the electronics industry, deionized water is used to rinse components during manufacturing. This is necessary to avoid potential short circuits that could destroy electronic chips. As electronic chips are very small, there is little free space between component elements and unwanted electricity may conduct across components via even a small number of ions, causing a short circuit. Using deionized water to clean the components helps minimize the ions on their surfaces and thus minimizes short circuits.
In the pharmaceutical industry, the presence of unwanted ions in water used in drug development can lead to unwanted side reactions and introduce harmful impurities.
In power generation, the presence of ions in boiler feedwater can lead to the buildup of solids or the degradation of boiler walls, both of which can lower boiler efficiency and present safety hazards.
Due to the large financial and safety concerns present in these three industries, their economic demand for highly pure water provides the bulk of the demand for EDI devices and development.
Electrodeionization systems have also been applied to the removal of heavy metals from different types of wastewater from mining, electroplating, and nuclear processes. The primary ions removed in these processes are chromium, copper, cobalt, and caesium, though EDI sees use in the removal of others as well.