73-13: Fuildized Moving Bed Ion Exchange for Treatment of Cooling Towers

During recent years, various pollution agencies have been setting standards on chromate discharge levels in cooling tower blowdown. These standards range from complete elimination of chromates to low effluent levels requiring the installation of elaborate and costly treatment systems which reduce and precipi­tate the chrome. 
In the early 1960's, the inclusion of chromates in blowdown was recognized as objectionable not only from an ecological standpoint, but also from the economic value of the lost chromate itself; and in 1965, a process was patented (1) utilizing an anion exchange resin to selectively remove chromate ions from waste water, and permit its recovery in a form suitable for reuse as a corrosion inhibitor.