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The Influence of Natural and Synthetic Additives in Mitigating Calcium Phosphate Scale in Industrial Water Systems

Der Einfluss von natürlichen und synthetischen Additiven auf die Verminderung des Calciumphosphat-Kesselsteins in industriellen Wassersystemen
Zahid Amjad and Amannie Kweik


The inhibition of calcium phosphate (Ca/P) precipitation by natural organic polyelectrolytes, bio- and hybrid polymers, homo- and co-polymers of acrylic acid and maleic acid containing different functional groups was examined in aqueous solution. Additionally, commonly used phosphonates were also evaluated as Ca/P inhibitors. It has been found that performance of additive (polymeric and non-polymeric) as Ca/P inhibitor depends upon additive concentration, ionic charge, and molecular weight. Based on the inhibition data, the ranking in terms of decreasing effectivess is: biopolymer > hybrid polymer > natural organic polyelectrolytes. Among synthetic polymers the ranking order is: terpolymer > co-polymer > homopolymer. Results on phosphonates evaluation reveal that compared to synthetic polymers, phosphonates show poor performance as Ca/P inhibitors.


Die Hemmung der Calciumphosphat (Ca/P)-Ausfällung durch natürliche organische Polyelektrolyte, Bio- und Hybridpolymere, Homo- und Copolymere aus Acrylsäure und Maleinsäure mit verschiedenen funktionellen Gruppen in wässriger Lösung wurde untersucht. Zusätzlich wurden die häufig als Ca/P-Inhibitoren verwendeten Phosphonate beurteilt. Es wurde gefunden, dass die Leistung des (polymeren und nichtpolymeren) Additivs als Ca/P-Inhibitor von der Konzentration, der ionischen Ladung und dem Molekulargewicht des Additivs abhängt. Basierend auf den Ergebnissen der Inhibitionsexperimente kann ein Ranking der absteigenden Wirkung aufgestellt weden: Biopolymer > Hybridpolymer > natürliche organische Polyelektrolyte. Unter den synthetischen Polymeren ist die Rangordnung: Terpolymer > Co-Polymer > Homopolymer zu erkennen. Die Bewertung der Phosphonate ergibt, dass Phosphonate als Ca/P-Inhibitoren eine im Vergleich zu synthetischen Polymeren schlechte Leistung aufweisen.

*Correspondence address, Dr. Zahid Amjad, Department of Mathematics and Sciences, Walsh University, 2020 E. Maple Street, North Canton, Ohio 44720, USA, E-Mail:

Zahid Amjad, Ph. D., has 30+ year experience in the water treatment, membrane separation processes, household, personal care, and pharmaceutical fields. He has published over 160 technical papers and is holder of 30 US patents. Dr. Amjad has edited nine books and has presented papers at national and international conferences. Dr. Amjad is a member of several professional societies and is a recipient of Association of Water Technologies 2002 Ray Baum Memorial Water Technologist of the year award. His current research interest include development and application of water soluble polymers, inhibition of mineral scale formation, and water purification. Dr. Amjad is a Visiting Professor in Chemistry at Walsh University, North Canton, Ohio.

Amannie Kweik recently graduated from Walsh University earning a Bachelor of Science in Biology with a minor in Chemistry. As a researcher working under Dr. Zahid Amjad, she is actively studying corrosion and scale inhibition by use of chemical additives. Her achievement is noted through several publications, leadership in research, and academic presentations. Beyond the lab, Amannie is perusing a career as a dentist.


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Received: 2017-05-25
Accepted: 2017-08-24
Published Online: 2017-11-13
Published in Print: 2017-11-15

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