Abstract
In open cooling water systems, phosphorus-based (P-based) programs are the most widely used treatment program for corrosion and scale control. Excellent performance of P-based programs has been long proved in many institutional and industrial applications. Despite this high performance, phosphorus is one of the limiting nutrients to bacteria and may accelerate microbial growth if with excess concentration. A recently developed and innovative non-phosphorus (non-P) program has been deployed globally, not only to comply with discharge regulations, but also to provide additional benefits/value to our customers. One feature of the non-P program is to eliminate/reduce phosphorous feed that enhances biological control. First case study of a non-P program is in a microelectronics plant. The new non-P program showed excellent corrosion, scale, and microbiol control performance. Superior performance of corrosion and scale control was demonstrated and is fully understood from a mechanistic perspective. For microbiol control, the bacteria count dropped two orders of magnitude after switching from an incumbent phosphorus-based program to the innovative non-P program. In the 2nd case study, an ethanol production plant recently switched from P-based program to the non-P program to improve the algae control in the discharge pond. After 10+ years suffering from algal bloom at summertime, very positive results have been observed. Moreover, corrosion control was further improved as reported.
