Challenge

This industrial plant provides disinfected, lime softened Trinity River water, demineralized water and steam to a number of surrounding plants. The 1 million gallon clear well was open to sunlight, and algae grew despite the presence of free chlorine. The presence of ammonia in the water and degradation of the bleach used as the disinfectant resulted in a very high feedrate.

Solution

Chlorine dioxide does not react with ammonia or many of the other naturally-occurring organics in surface water, allowing a chlorine dioxide feedrate of 1 – 2 mg/L versus a bleach feedrate of ~ 10 mg/L.

Results

After implementation of the chlorine dioxide treatment program, the demineralizer run lengths increased. Over time, the average increase in demineralizer run lengths was around 4%. This resulted from a substantially lower level of sodium ions present in the chlorine dioxide solution compared to that of bleach. In addition, this plant, which had been demineralizer limited, reevaluated their need for an additional demineralizer.