Mark Edward Bush

US Patent:

48184136, Apr 4, 1989

Filed:

Aug 5, 1987

Appl. No.:

7/081857

Inventors:

Richard L. Hoover - St. Charles IL
Mark A. Bush - Louisville KY

Assignee:

Nalco Chemical Company - Naperville IL

International Classification:

C02F 176

US Classification:

210739

Abstract:

The copper corrosion rate is minimized to a certain discharge limit by providing a chlorine-bromide treatment in which the chemical feed rate of bromide is increased to an amount required to decrease the copper corrosion rate to the rate required to meet the discharge limit. The inventors made the unexpected and surprising discovery that an increase in the chemical feed rate of bromide--even when the chlorine feed rate is constant--has the effect of reducing copper corrosion. Therefore, this effect is useful for adjusting the copper corrosion rate to an optimum rate to most economically achieve a certain discharge limit. In a preferred embodiment of the invention, the biocide water treatment program includes the steps of measuring the copper corrosion rate during a chlorine-bromide treatment interval, computing the value of copper discharge from the measured copper corrosion rate, comparing the computed value of copper discharge to the discharge limit, and adjusting the bromide chemical feed rate based on the comparison, to thereby economically achieve an amount of copper discharge within the discharge limit.