Materials Performance

NOV 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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55 NACE INTERNATIONAL: VOL. 53, NO. 11 MATERIALS PERFORMANCE NOVEMBER 2014 Impact of Iron Oxide on Calcium Carbonate Inhibitors—Part 1 decrease in a solution's calcium concentra- tion i s f irst d et e ct ed) in crea se s w ith increasing HP1 concentration. For exam- ple, %I values at 24 h, calculated according to Equation (1), for 0.50 and 1.0 mg/L of HP1 are 35 and 58%, respectively, compared to 74% obtained at 1.5 mg/L of HP1. Data depicted in Figure 1 also show that increas- ing the HP1 concentration ( from 0.5 to 1.0 mg/L) leads to a significant increase (i.e., from 40 to 60%) in the %I values. It is worth n o t i n g t h a t % I v s . d o s a ge p r of i l e a s observed for HP1 in the present study has been reported for CaCO 3 inhibition by both synthetic and natural additives. 9 Effect of Polymer Architecture To understand the impact of a type of functional group [anionic (–COOH, –SO 3 H), non-ionic ( ), and cationic ( )] pres- ent in a polymer, a series of precipitation experiments were carried out in the pres- ence of 2.5 mg/L of various homopolymers. Figure 2 presents inhibition data for HP1; carboxymethyl inulin (CMI-25, with 25% degree of carboxylation) (HP2); poly(2-ethy- loxazoline) (HP3); and poly(diallyldimethyl ammonium chloride) (HP4). There are two points worth noting in Figure 2: (a) polymers such as HP3 and HP4 that contain a neutral group and cationic charge group, respectively, are ineffective CaCO 3 inhibitors; and (b) polymers contain- ing a –COOH group (HP1, HP2) exhibit good performance as a CaCO 3 inhibitor. For example, compare %I values obtained for HP3 and HP4 (<3%) to 61 and 74% obtained for HP1 and HP2, respectively. This perfor- mance trend observed in the present study is in agreement with results reported on these polymers for other scaling systems, including CaSO 4 ·2H 2 O and CaF 2 . 8-10 While HP3 and HP4 show poor perfor- mance as CaCO 3 inhibitors, it is worth pointing out that these polymers have been reported to exhibit excellent performance as silica polymerization inhibitors. 11-12 Thus, from the data presented in Figure 2, it is evi- dent that polymers containing the –COOH group (HP1, HP2, HP5, and CP1) perform better than polymers containing the non- ionic or cationic charge group (HP3, HP4). This suggests that an ionic charge present in the polymer plays an important role in imparting an inhibitor y property to the polymer. References 1 The Science and Technolog y of Industrial Water Treatment, Z. Amjad, ed. (Boca Raton, FL: CRC Press, 2010). 2 P.G. Klepetsanis, et al., "Calcium Carbonate and Calcium Phosphate Scale Formation and In h i b i t i o n a t E l e v a t e d Te m p e ra tu re s ," A d v a n c e s i n C r y st a l G row t h In h i b i t i on Technologies, Z. Amjad, ed. (New York, NY: Kluwer Academic Publishers, 2000). 3 M. Miura, H. Naono, S. Otani, "Effects of Various Condensed Phosphates on the Crys- tallization and Crystal Habit of Calcium Car- bonates," Kog yo Kagaku Zassahi 66 (1963): pp. 597-601. 4 P. G. Klepetsanis, A. Kladi, P. G. Koutsoukos, Z. Amjad, "The Interactions of Water Soluble Polymers with Solid Substrates, Implications on the Kinetics of Crystal Growth," Progress in Colloid and Polymer Science 116 (2000): pp. 1,006-1,011. 5 P. Somasundaran, V. Ruknkana, "Interactions of Polyelectrolytes with Particulate Matter," The Science and Technolog y of Industrial Water Treatment, Z. Amjad, ed. (Boca Raton, FL: CRC Press, 2010). 6 Z. Amjad, D. Butala, J. Pugh, "The Influence of Recirculating Water Impurities on the Per- formance of Calcium Phosphate Inhbiting Polymers," CORROSION/99, paper no. 118 (Houston, TX: NACE International, 1999). 7 Z. Amjad, J.F. Zibrida, R.W. Zuhl, "A New An- tiscalant for Controlling Silica Fouling in Re- verse Osmosis Systems," IDA World Congress on Desalination and Water Reuse (Topsfield, MA: IDA, 1997). 8 Z. Amjad, D. Guyton, "Gypsum Scale: Inf lu- ence of Rust Particles on the Performance of Inhibitors," UltraPure Water 28, 9 (2011): pp. 25-30. 9 P.G. Klepetsanis, A. Kladi, P.G. Koutsoukos, Z. Amjad, "The Interactions of Water Soluble Polymers with Solid Substrates. Implications on the Kinetics of Crystal Growth," Progress in Colloid and Polymer Science 116 (2000): pp. 1006-1011. 10 Z. Amjad, "Inf luence of Calcium Fluoride Crystal Growth by Polyelectrolytes," Lang- muir 7 (1991): pp. 2,405-2,408. 11 E. Neofotistou, K. Demadis, "Use of Antiscal- ants for Mitigation of Silica (SiO 2 ) Fouling and Deposition: Fundamentals and Applica- tions in Desalination Systems," Desalination 167 (2004): pp. 257-272. 12 M. Yorke, Z. Amjad, "Carboxylic Functional Polyampholytes as Silica Polymerization In- hibitors," U. S. Patent 4510059, 1985). 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 appli- cations. He has taught undergraduate and graduate-level chemistry courses. He has edited seven books on various aspects of water treatment; presented papers at national and international conferences including NACE, IWC, AWT, ACS, and others; and has published more than 150 journal articles. A NACE member since 1 9 8 5 , A m j a d r e c e i v e d t h e A W T Technologist of the Year Ray Baum Memorial Award and has organized technical symposia for NACE and ACS conferences. JEREMY L. PENN is a student in the Division of Mathematics and Sciences, Walsh University. He is working toward a B.S. degree in biology while minoring in chemistry and sociology. He plans to continue his studies to obtain a Ph.D. in science. Need reprints of MP ads, articles, or covers? REPRINTS ARE A GREAT INVESTMENT! Professionally printed reprints and photo copied reprints of all MP ads, articles, and covers are available for purchase. Reprints can be customized with your company's logo, additional product information, or the magazine cover—with no limits on creativity! Order your reprints today; it simply makes good business sense! For reprint information and rates, call +1 281-228-6287.

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