A chemical free process for creating ultra-pure, deionized water, electro deionisation (EDI) combines two separation technologies, membrane and ion exchange, into one sealed, self-contained unit. The primary use of EDI has focused on the polishing of reverse osmosis permeate. EDI technology is becoming widely used in industry as a final polisher replacing traditional ion exchange units which require chemical regeneration using caustic and acid reagents.
The EDI modules use electrical current to force a continuous migration of contaminant ions out of the feed water and into the reject stream while at the same time continuously regenerating the resin bed with hydrogen and hydroxyl ions that are created by the electric current.
EDI plants are environmentally friendly to operate and have lower operating casts than traditional chemically regenerating ion exchange plants. EDI requires no regeneration chemicals and produces no hazardous wastes.
