(Electro De-ionization)EDI: is a water treatment technology that utilizes an electricity, ion exchange membranes and resin to deionize water and separate dissolved ions (impurities) from water. It differs from other water purification technologies in that it is done without the use of chemical treatments and is usually a polishing treatment to reverse osmosis (RO). There are also EDI units that are often referred to as continuous electro deionization(CEDI) since the electric current regenerates the resin mass continuously. CEDI technique can achieve very high purity, with conductivity below 0.1 µS/cm.EDI products are used worldwide to produce ultrapure water systems in diverse applications, including power generation, pharmaceutical, semiconductor, petrochemical and laboratory pure water systems.