78-12: Chromate Handling Systems for Cooling Tower Blowdown

Chromate-based inhibitors have been widely used in cooling systems for corrosion control for many years. However, recent environmental legislation has increased restrictions on industrial chromate discharge. Hexavalent chromate can be removed from cooling tower blowdown by either reducing it chemically or electro­chemical1y1 •2 to the trivalent form or by ion exchange and reuse in the system.