Materials Performance

DEC 2014

Materials Performance is the world's most widely circulated magazine dedicated to corrosion prevention and control. MP provides information about the latest corrosion control technologies and practical applications for every industry and environment.

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56 DECEMBER 2014 MATERIALS PERFORMANCE NACE INTERNATIONAL: VOL. 53, NO. 12 CHEMICAL TREATMENT matter to varying degrees. Generally, c o a n d t e r p o ly m e r s a re b e tt e r di sp ersants than homopolym ers. Additive performance is affected by the amount of Fe 2 O 3 present in the s u p e r s a t u ra t e d s o l u t i o n , w h i c h suggests the additive concentration in solution is depleted via adsorption onto Fe 2 O 3 particles. d) Interactions of Fe(III)hydroxo com plexes with additives: It is likely that Fe ( I I I ) hyd roxo c o m p l e xe s [i . e . , Fe(OH) 2+ , Fe(OH) 2 + , Fe 2 (OH) 2 4+ , etc.], formed in the aqueous solution inter acted with anionic additive mole cules, which led to decreased solution concentration of the additive. Based on this study, it is likely that one or more of the proposed mechanism(s) is responsible for the marked decrease in additives' performance as CaCO 3 inhibi tors. Studies are currently underway to bet ter understand the additive performance loss. Conclusions A wide variety of additives are used in water treatment formulations to combat deterioration of metallic parts, microbio logical growth, scale formation, and sus pended matter deposition. The authors' earlier laboratory work showed that the performance of additives depends largely on water chemistry, type and amount of soluble and insoluble impurities, additive composition, and suspended solids. The data in this article show that CaCO 3 precipitation in an aqueous solution can be prevented by the addition of small amounts (<5 ppm) of homo and copolymers con taining different functional groups. The data also show that a polymers' perfor mance as a CaCO 3 scale inhibitor strongly depends on polymer architecture. SEM micrographs and XRD data show that mor phology of CaCO 3 is strongly impacted by additives and Fe 2 O 3 particles. Additionally, the data in this article show that small amounts (5 to 100 mg) of Fe 2 O 3 particles can significantly decrease the polymers' performance. The data fur ther reveal that the negative inf luence shown by the addition of Fe 2 O 3 to a CaCO 3 supersaturated solution can be overcome by increasing the inhibitor concentration. In selecting a polymer, water technologists should consider the various factors previ ously discussed, as well as metallurgy and compatibility with cationic biocides. Acknowledgments The authors thank Professor Peter G. Koutsoukos, University of Patras, Patras, Greece, for CaCO 3 polymorphs character ization by SEM and XRD and for helpful discussion. Thanks also to Walsh University for support to carry out the research and p r e s e n t t h e f i n d i n g s a t t h e N A C E International annual convention. References 1 Z. Amjad , The Science and Technolog y of Industrial Water Treatment (Boca Raton, FL: CRC Press, 2010). 2 Z. Amjad, D. Guyton, "Gypsum Scale: Inf lu ence of Rust Particles on the Performance of Inhibitors," UltraPure Water 28, 9 (2011): pp. 2530. 3 Z. Amjad, "Inf luence of Natural and Syn thetic Additives on Calcium Carbonate Pre cipitation and Crystal Morphology," Tenside Surfactants Detergents 43, 3 (2006): pp. 184 191. 4 Z. Amjad, "Inf luence of Calcium Fluoride Crystal Growth by Polyelectrolytes," Lang- muir 7 (1991): pp. 2,4052,408. 5 Z. Amjad, "Inhibition of Barium Sulfate Pre cipitation: Effects of Additives, Solution pH, and Supersaturation," Water Treatment 9 (1994): pp. 4756. 6 Z. Amjad, J. Pugh, J.F. Zibrida, R .W. Zuhl, "Polymer Performance in Cooling Water— The Influence of Process Variables," MP 36, 1 (1997): pp. 3238. 7 Z. Amjad, "Dispersion of Iron Oxide Particles in Industrial Waters," Tenside Surfactants Detergents 36 (1999): pp. 5056. 8 S. Sarig, F. Kahana , "On the Association Between Sparingly Soluble Carbonates and Polyelectrolytes," J. Crystal Growth 35 (1976): pp. 145150. 9 E. Dalls, J. Kallitsis, P.G. Koutsoukos, " The Cr ystallization of Calcium Carbonate on Polymeric Substrates," J. Crystal Growth 89 (1988): pp. 287293. 10 Y. Kitano, S. Kanamori, A. Tokuyama, "Effects of Organic Matter on Solubility and Crystal Form of Carbonates," American Zoologist 9 (1969): pp. 681685. 11 R .E. Herzog, Q. Shi , J.N. Patel , J.K. Katz, "Magnetic Water Treatment: The Effect of Iron on Calcium Carbonate Nucleation and Growth," Langmuir 5 (1989): pp. 861867. 12 Z. Amjad, "Interactions of Hardness Ions with Polymeric Scale Inhibitors in Aqueous Systems," Tenside Surfactants Detergents 42 (2005): pp. 7177. ZAHID AMJAD is a visiting professor, Division of Mathematics and Sciences, Walsh University, 2020 E. Maple St., N. Canton, OH 44720. He has worked in research and development for more than 30 years, developing new proprietary antiscalants and dispersants for industrial water systems including boiler, cooling, desalination, oilfield, and home care applications. He has taught undergradu- ate and graduate-level chemistry courses. He has edited seven books on various aspects of water treatment; presented papers at national and international con- ferences including NACE, IWC, AWT, ACS, and others; and has published more than 150 journal articles. A NACE member since 1985, Amjad received the AWT Technologist of the Year Ray Baum Memo- rial Award and has organized technical symposia for NACE and ACS conferences. JEREMY L. PENN is a student in the Divi- sion of Mathematics and Sciences, Walsh University. He is working toward a B.S. degree in biology while minoring in chem- istry and sociology. He plans to continue his studies to obtain a Ph.D. in science. Read MP Online NACE International members have free access to MP Online, with back issues to 2005. Visit MP Online in the Publications area of the NACE Web site:

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