Question:
We are looking for equipment/apparatus for softening and purificationwater by electrochemical deionization - ion exchange. Is there suchequipment and which companies are manufacturing it?

Answer: Otherwise, the other electrochemical technology is CDI. US Filter sells this. To my knowledge, CDI may have a role in high puriity water. This technology needspurified water to begin with. It is also supposed to be sensitiveto extremely small amounts of Ca and other ions. Because it hasa serpentine flow path, it is extremely sensitive to fouling. CDIis a hybrid of membrane and ion exchange, and has some of the bad qualitiesof both. The Flow through capacitor has none of these problems.

BIOSOURCE, INC.

The first significant new technology in the field of waterpurification in over fifty years has just received two issued USpatents; US 5,547,581 to Marc Andelman, Worcester, MA and US 5,538,611to Toshi Otowa, Shiga Prefecture, Japan, assigned to Marc Andelman. Alicensing agreement for the Japanese market has been signed by aJapanese chemical company. This technology, called a flow through capacitor, removesdissolved contaminants from water without pollution causing chemicals orexcessive waste water caused by the existing, century old technologiesin this field; ion exchange and reverse osmosis. For residentialsystems, the flow through capacitor will make possible a salt-less watersoftener. Traditional ion exchange systems are slowly being outlawedbecause they add large amounts of salt to water with adverse health andenvironmental effects. Ion exchange, used in common household watersofteners, continuously adds salt to the water and also createssecondary brine or acid waste. These chemicals are required toregenerate the ion exchange bed. The other major existing technology,reverse osmosis, wastes 50% or more of the feed stream... down thedrain. No reasonable alternative technology has existed until now. The flow through capacitor is configured as a water filter madeup of alternating electrodes of ordinary, inexpensive activated carbon.Activated carbon is conductive and has an extremely high surface area,up to 3000 square meters/gram. Upon supplying a small voltage,contaminated water is rapidly purified due to the fact that thedissolved contaminants attract to the high surface area carbon material,allowing purified water to pass through. Once the capacitor is fullycharged, the electrodes are short circuited through a load. Thisregenerates the capacitor and causes the absorbed contaminants to bereleased from the carbon material as a small volume of concentratedliquid waste. Alternatively, the capacitor can be used as an ion pump torecover the contaminants as a solid, thereby eliminating waste waterentirely. Energy consumption of a flow through capacitor, measured withhard well water, is five times less than reverse osmosis. Additionalenergy efficiency can be gained simply by recovering the storedelectricity released by the capacitor during the regeneration stage. Theflow through capacitor's efficiency is due to the fact that it removessalts from water, as opposed to removing water from salts. Anticipated markets include desalination, nuclear waste cleanup,pollution remediation, blood purification as in dialysis, municipalwater purification, large scale restoration of lakes and aquaticecosystems, a general method to recycle chemical wastes fromelectroplating or manufacturing processes, and in place of added watertreatment chemicals.