75-07: Recovery of Chromate from Cooling Tower Blowdown by Ion Exchange ResinsDuring the past several decades, chromate based corrosion inhibitors were widely used in open cooling water recirculating systems. In 1971, the Japanese Government, however, adopted a regulation which limited the discharge of toxic matter including hexavalent chrome to public waters. Factories employing cooling systems were forced to reduce chromates to less than 0. 5 ppm as Cr^6+ or replace chromates to other types of corrosion inhibitors; however,

A plethora of materials

has made many of us make significant change in our thinking and the method of treatment in cooling towers

the author will illustrate how a risk analysis and consequently a risk management program are the first requirements for operating a Cooling Tower System safely

Revised August 2022

elevated temperature capability

The turbidity of river water varies in the range of 70-500 NTU with lower value typically noted in the summer and higher value during the rainy season

high calcium ion concentrations and high alkalinity at high pH makes control of calcium carbonate extremely critical

Although microbicides are widely utilized to keep cooling water free of contamination

alkaline cooling waters and provide increased cycles of concentration without the need for acid feed

The strategies presented will cover basic operational methods

including investigation of potential potable water sources

As an alternative to pure commercial CO2