Problem:

Proper sanitation of the raw water at Phoenix NAB is of utmost importance.  Failure to do proper sanitation will have serious health implications, as most of the water is used in the process for the manufacture of cool drinks for human consumption.  Sodium Hypochlorite was previously dosed by means of a small chemical dosing pump into the make-up water line. When the incoming water flow rate increase the sodium hypochlorite dosing pump needed to be adjusted manually to ensure the correct levels were maintained for proper sanitation. Further problems were encountered as the dosing line became blocked due to crystallization of the chemicals in the tubing. It was also discovered that there were abnormally high levels of bromates and chromates in the finished product. The major contributing factor to these increased levels was found to be the Sodium Hypochlorite.

Solution:

On the incoming water holding tank a recirculation system was installed. This was accomplished by installing a pump on the suction side of the holding tank pump and returning the water back to the holding tank. A venturi system was installed on the recirculation line which would remove the chlorine solution from the Pulsar 3. The HTH® Controller was installed and is used to monitor and control the correct free chlorine levels in the holding tank. This would ensure that the holding tank’s free chlorine levels were correct at all times (6-8ppm), which means that water system is properly sanitized. Calcium Hypochlorite (Scientific HTH Chips) was found to significantly reduce the levels of bromate and chlorate in the final product when compared to sodium hypochlorite and the manufacturer’s specification.

The HTH Controller Trolley

The reagents and Colorimeter of the Controller