Benefit No. 1: State-of-the-art-technology
A little history: Millipore and electrodeionization (EDI) development
Starting in the early 1980s, Millipore began to build on existing electrodeionization technology (first invented in the 1950s (1,2). By concentrating significant research capacity on this promising technology, Millipore was able to develop a second-generation EDI (Elix) module in 1996. This module introduced mixed-bed resins in the concentrating (waste) compartments, as well as a development covered by a U.S. patent: the inclusion of carbon beads in the cathode compartment (3) . These changes made it possible to reduce the electrical supply required by the module and also eliminate the need for water softeners.
Several years later, this module was followed by the third and latest generation of EDI design. This newest Elix module incorporates scalability, segmented electrodes that enable optimum DC amperage to deionize and regenerate the ion exchange resins in each of the module's sub-compartments (E.U. patent No. 1466656) (4) , as well as the ability to operate with higher concentrations of CO2 in the feed water without any negative effects on product water quality.
Continuous improvement
EDI is a sustainable technology that combines the strengths of several key purification technologies or media. The EDI module is never used as a stand-alone device, but instead constitutes an integral part of a global water purification system that can include a pretreatment pack, RO technology and a germicidal ultraviolet (UV) lamp. Our objective of continuous improvement has led us to identify several ways that EDI technology might be further improved. Today Millipore R&D researchers are evaluating these hypotheses; we are convinced that the results of these and other investigations will shape future technological advances in EDI development.
(1) Walters, W.R.; Weister, D.W.; Marek, L.J. "Concentration of Radioactive Aqueous Wastes – Electromigration through Ion-Exchange membranes," Indust. Engin. Chem., 47, 61-67, (1955).
(2) Kollsman, P. in U.S. Patent No. 2,815,320, "Method of and Apparatus for Treating Ionic Fluids by Dialysis," (1957).
(3) Denoncourt, J.P. and Moulin, J. in U.S. Patent No. 5,593, 563, "Electrodeionization Process for Purifying a Liquid," (1997).
(4) De Los Reyes, G.; Yacteen, W.; Bejtlich, C.L.; Sarioglu, T. in E.U. Patent No. 1466656.