The learners will understand the limitation of scale prediction simulations and indices 

They will observe the application of indices and their meaning in typical cooling water

What are indices and saturation ratios

Where and how can a simple index such as the Langelier Saturation Index or similar indices for silica and calcium phosphates be applied?

When and why are more sophisticated appropriate?

Do indices mean the same thing in different systems and varying water chemistry?

is ther a relationship between indices. dosages and treatment failure points?

Rob Ferguson

Predictive models and tests have evolved significantly since the marble test of the early twentieth century, the simple driving force indices such as the father of all indices, the Langelier Saturation Index in the 1930s, through the early speciation engines of the 1970s and onto the  high ionic strength models of the twenty first century. Other models such as the Calcium Carbonate Precipitation Potential and momentary excess, predict the quantity of scale precipitation that might be expected.

This paper discusses the differences between the indices and their interpretation.

Simulating precipitation from untreated water is also discussed.

Rob Ferguson began developing computer models for predicting and controlling scale and corrosion from industrial waters in 1974. Major accomplishments include 

* the development of the first user friendly, practical scale predictive programs

* developing the first dosage modelling systems to include driving force, time and temperature impacts

* designing and implementing the first real time controller for dosage optimization

* developing and marketing the first economical, PC based, user friendliy water treatment simulation software which has become the industry standard world wide

* providing tools for small water treatment service companies that equaled or surpassed those used by the billion dollar corporations

He cofounded French Creek Software  in 1989  and is proud that French Creek was honored as an AWT supplier of the year. Rob is a Ray Baum award winner and a frequent contributor to AWT annual conferences and the Analyst His motto is PChem for fun and profit.