Advance the understanding of chemical differences and key applications of polymers, phosphonates, and polymer/phosphonate combinations as deposit control agents in industrial water treatment.

• Deposit control polymers and phosphonate as individual additives are important to any water treatment program, but a one-size-fits-all solution does not exist. There is a demonstrated history of phosphonate efficacy being dependent on the inclusion of a deposit control polymer, but the limits of these combinations warrant further exploration. 
• Water matrix and conditions affect the efficacy of deposit control polymers and phosphonates alike. Using a combination of both static and dynamic test methods allows for exploration of a wider range of process variables than either test method on its own. Exploring combinations of polymers and phosphonate inhibitors under variable scaling conditions helps to highlight chemical differences and understand key applications for the individual and combined deposit control agents.
• There can be synergistic effects to utilizing combinations of polymers and non-polymeric inhibitors. The combination of additives can increase the elapsed time to scale and/or reduce the amount of scale formed in a given time period more than the summation of the individual products. 

Dr. Emily Pronovost

Deposit control polymers (DCPs) and organophosphonates compounds are multi-functional components of any water treatment program. DCPs disperse particulates, inhibit scale formation, and stabilize metal ions, while phosphonates act as scale and corrosion inhibitors. A diverse water treatment portfolio could consist of multiple types of both polymeric and non-polymeric additives, as DCPs are necessary to treat waters saturated with calcium phosphate, while phosphonates protect heat exchangers from corrosion and are effective inhibitors of calcium carbonate.

In this study, the synergistic effects of combining additives to target calcium carbonate and calcium phosphate mineral scales is explored using static and dynamic test methods. Polymer and phosphonate deposit control agents were evaluated under the influence of various process variables (pH, temperature, etc.) to highlight chemical differences and key applications for polymers, phosphonates, and polymer/phosphonate combinations.

Dr. Emily Pronovost has worked at Lubrizol for 6 years as a chemist in the Specialty Additives group focusing on the technical support and product development for oilfield applications and industrial water treatment. Prior to joining Lubrizol, she worked in municipal environmental monitoring and served in the U.S. Navy. Emily earned her Ph.D. in Chemistry from the University of Texas at San Antonio specializing in bio-based nanotechnology and photochemistry.