AWT-00 (Oct-00)

Association of Water Technologies, Inc. 12th Annual Convention & Exposition

31 October to 4 November 2000 The Hilton Hawaiian Village, Honolulu, Hawaii

The Effect of Biocides on Deposit Control Polymer Performance

Zahid Amjad, Ph.D. and Robert W. Zuhl, P.E. Lubrizol Advanced Materials, Inc.* (Cleveland, OH)

and

John F. Zibrida, ZIBEX, Inc. (Duluth, GA)

© 2007 The Lubrizol Corporation, all rights reserved. * Formerly Noveon, Inc. ** Formerly Good-Rite K-700 Water Treatment Polymers.

Carbosperse™ K-700 Water Treatment Polymers**

1

Introduction In the field of water treatment a variety of additives are incorporated into formulation to achieve certain desired performance objectives of the industrial water systems. Typical additives used include polyphosphates, organophosphonates, poly(acrylic acid), poly(maleic acid), and copolymers containing a variety of functional groups such as carboxyl, acrylamide, sulfonic acid, ester, etc. The main function of these additives in the formulation is to prevent the deposition of unwanted deposits (i.e., mineral scales, corrosion products, biomass, suspended matter, etc.) on equipment surfaces. A variety of corrosion control additives are also incorporated into water treatment formulations to control the deterioration of metal – based equipment such as heat exchangers, pipes, and pumps. Common additives used for corrosion inhibitors include polyphosphates, organophosphonates, tolyltriazole, and benzotriazole. Furthermore, other additives are also used to control the formation and deposition of microbiological film on heat exchangers.1 Currently, a large variety of polymer-based additives are commercially available and they possess a wide range of physical and chemical properties, molecular weights (ranging from few hundreds to several thousands), and purity. For example, poly(acrylic acids) or PAAs produced by different manufacturers can have distinctly different properties. Thus, the selection of polymer should be based on technical/business need and customer requirements. In addition to differences due to polymer characteristics, other factors including solution pH, temperature, ionic strength, cation type, and concentration can influence the performance of polymers as scale inhibitor or particulate dispersant. In previous papers from our laboratories, we have demonstrated that acrylic–based co- and terpolymers, compared to homopolymers such as PAA and poly(maleic acid) are excellent calcium phosphate and calcium phosphonates inhibitors for cooling water systems.2,3 In other studies, it was reported that for other mineral scales (e.g., calcium fluoride, barium sulfate, calcium sulfate), low molecular weight homopolymers perform better than co- and terpolymers, thus suggesting that carboxyl group plays an important role in influencing the inhibitory power of the polymer.4,5 The type and extent of coagulation/flocculation process for the removal of suspended matter from surface water has been reported to exhibit a marked antagonistic effect on the performance of polymers used in cooling water treatment formulations. It has been shown that the effectiveness of coagulants/flocculants strongly depends on several parameters including pH, temperature, mixing, and residence time. Chemicals commonly used as coagulants or flocculants include alum, ferric chloride, and cationic polymers such as diallyldimethyl ammonium chloride (DADMAC). These chemicals are known to “carryover” and have been reported to decrease the performance of calcium phosphate inhibiting polymers.6,7 Thus, the presence of these impurities in the water may necessitate higher polymer dosage to inhibit scale formation and growth in the system. In addition to corrosion, scale, and suspended matter, the performance of industrial water systems is also seriously affected by the deposition of microorganisms on the heat exchangers. Problems occur when microbes begin to proliferate and attach to

2

equipment surfaces, thus resulting in decreased heat exchanger performance. Corrosion can also result from unchecked microbial growth. Microorganisms such as algae, fungi, and bacteria can combine with organic compounds to form biofilms. The microbes in these films generate metabolites that are corrosive in nature. The net result of this process is microbial induced corrosion (i.e., pitting and corrosion of metal parts). The deposition of scale, suspended matter, corrosion products, and biofilms on heat exchangers results in decreased heat exchanger efficiency, reduced flow capacity, increased maintenance costs, etc. To prevent the formation of biofilm and to achieve optimum system efficiency, microbiological growth within the water system must be controlled. Generally, biofilm formation is controlled by the addition of biocides, biostats, and biodispersants to the water system. Currently available biocides vary considerably in terms of their characteristics such as chemistry, biodegradability, compatibility with other additives, activity, and selectivity. Both oxidizing and non-oxidizing biocides find application in water treatment market. Some commonly used biocides include chlorine, ozone, chlorine dioxide, quaternary ammonium chloride, gluteraldehyde, etc. Biocide performance depends upon the following factors:8

• Type of biocide • Biocide concentration and application frequency • Biocide demand • Contact time • pH • Temperature • Types of organisms present • Presence of biofilm • Interaction(s) with other dissolved substances • Microorgansim loading • Existing corrosion

Historically, the performance of polymers for mineral scale control in the presence of soluble and insoluble impurities has been heavily researched. However, the effect of biocide on the inhibitory activity of polymers commonly used in water treatment formulations has been mostly overlooked. This paper explores the influence of several commercial biocides on the inhibitory and dispersancy aspects of several polymers commonly used in water treatment formulations. The biocides evaluated in this investigation vary significantly in chemistry ranging from simple molecule to complex species. It is hoped that the results presented in this paper will help explain why a specific polymer does not perform as expected, and how polymer dosages can be adjusted to achieve optimum performance. The polymers and biocides evaluated in the present study are summarized in Tables 1 and 2, respectively.

Experimental The polymers and biocides used for this study were selected from commercial materials. All polymers and biocides solutions were prepared on dry weight basis. The desired concentrations were obtained by dilution. Stock solutions of calcium chloride

3

and disodium hydrogen phosphate were prepared using distilled water and analyzed for calcium and phosphate as described previously.2 A Metrohm Brinkmann pH-stat unit equipped with a combination electrode was used to measure pH. The pH electrode was calibrated before each experiment with standard buffers. The test solution temperature was maintained to 50 ± 0.5ºC by passing controlled water through the outer jacket of the double walled reaction cell. The sub-saturated calcium phosphate solution was made by the slow addition of the phosphate stock solution to the desired water. The calcium phosphate inhibitor and other ionic constituents were added and the solution pH was adjusted if necessary, after a 30 minutes equilibration period. The calcium stock solution was added, making up the total volume to 600 mL. In experiments involving the biocide a known amount of biocide stock solution was added to the test solution following temperature stabilization but prior to pH adjustment and before the introduction of the calcium solution. For all experiments, the reaction period was fixed at 20 hours. During each experiment, the test solution pH was maintained (within ±0.01 pH units) at the desired value using the pH-stat unit illustrated in Figure 1. Unless specified, the standard test conditions for calcium phosphate inhibition were 140 mg/L Ca, 9.0 mg/L phosphate, pH 8.50, 50 ºC, 20 hr, and 10 ppm polymer. The reaction progression was determined by spectrophotometric analysis of filtered (0.45 micron) aliquots of the test solution for the phosphate ion.2 The polymer efficacy as a calcium phosphate inhibitor was calculated using the following equation:

% Inhibition (I)

[PO4] exp – [PO4] final

[PO4] initial – [PO4] final

x 100

Where:

[PO4] exp = phosphate concentration in the filtrate in the presence of the inhibitor at 20 hr.

[PO4] final = phosphate concentration in the filtrate in the absence of inhibitor at 20 hr.

[PO4] initial = phosphate concentration at the beginning of the experiment. The effect of biocides on the performance of polymers as iron oxide dispersants was evaluated according to the procedure described previously.9

Results and Discussion The use of deposit control polymers as inhibitors/dispersants in water treatment formulations has increased significantly over the last two decades. The role of polymers in these formulations is to inhibit the precipitation of scale forming salts and to prevent the deposition of unwanted materials on the equipment surfaces. It is generally agreed that these polymers operate by adsorption onto submicroscopic crystallites, thereby preventing further crystal formation and deposition.

4

Most commercially available polymers are acrylic acid or maleic acid based homo- and co-polymers that have been proven to be effective under most typical cooling water conditions. However, the demands on polymer performance have increased due to trends towards operating cooling systems under more severe conditions to increase process efficacy, safety, and water conservation. Additionally, results of recent studies have shown that the efficacy of these polymers is adversely impacted by the presence of low levels of impurities commonly encountered in feed streams.6,7,9,10 The following section present results on the influence of various biocides on the inhibitory power of several commercially available calcium phosphate inhibiting polymers. Calcium Phosphate Inhibition The use of biocide to control microrgansims in cooling water systems is well documented.11-13 The type and selection of biocide types is dependent on systems design, loading and desired results. The desired biocontrol may include the use of several types of biocontrol agents. The application of these may be continuous or intermittent. Biodispersants are used to improve the effectiveness of biocides. Recent recommendations on the control of legionella pneumophila suggest the use non-oxidizing biocides in combination with either continuous or intermittent halogen addition.14 Biocides are commonly applied in the presence of deposit and corrosion control agents. Accordingly, the interaction of biocides on the other components of the water treatment program is of interest. This study evaluated the effects of a variety of commonly used oxidizing and non-oxidizing biocides as shown below:

• Oxidizing biocides: Chlorine and a bromine chlorine compound. • Non-oxidizing biocides: Dithiocarbamates, isothiazoline, gluteraldehyde,

2,2-Dibromo-3-nitrilopropionamide (DBNPA), tris (hydroxymethyl) nitromethane, tetrakishydroxy methyl phosphonium sulfate (THPS), quaternary ammonium compounds (quats), and several biodispersants.

Oxidizing Biocides

The results of our testing on oxidizing biocides (Cl2 and Br-Cl) for Polymer B are presented in Figure 2. The results clearly show no appreciable effect of oxidizing biocides on polymer performance at the conditions tested (10 to 100 ppm). However, it is well known that other typical water treatment additives (e.g., azoles, phosphonates, etc) are susceptible to degradation in the presence of oxidizing biocides. Oxidizing biocides are also known to increase corrosion and thus the levels of corrosion products may also increase. Therefore, field applications incorporating both polymers and oxidizing biocides may have different results as other processes (e.g., corrosion, precipitation) may occur. The polymers tested in this study, demonstrated resistance to a loss of performance in the presence of oxidizing biocides.

5

Non-Oxidizing Biocides

The effect of several non-oxidizing biocides on the performance of calcium phosphate inhibiting polymers was investigated by conducting a series of experiments under standard test conditions. The non-oxidizing biocides evaluated contain different functional groups and included DBNPA (NOx-1), dithiocarbamates (NOx-2), gluteraldehyde (NOx-3), trisnitromethane (NOx-4), and isothiazoline (NOx-5). Figure 3 shows the results on these experiments and indicates that 5, 10, and 50 ppm dosage of these biocides do not significantly affect the performance of Polymer B. We also studied the influence of cationic biocides such as THPS (NOxC-1, a positively charged phosphonium biocide), dialkyldimethyl ammonium chloride [NOxC-2], and n-alkyldimethyl benzyl ammonium chloride (MW 364 and 351) [NOxC-3 and NOxC-4, respectively] as a function of concentration on the performance of Polymer B. The results presented in Figure 4 show that NOxC-1 biocide does not show any antagonistic effect on the performance of Polymer B. However, the results are markedly different for the quaternary ammonium compounds (quats) tested. Figure 4 illustrates that the performance of Polymer B is strongly dependent on the concentration of the biocide present in the calcium phosphate supersaturated solution for all three (3) quats (NOxC-2, NOxC-3, and NOxC-4). The data presented in Figure 4 also suggest that the alkyl (NOxC-2) and benzyl (NOxC-3 and NOxC-4) quat biocides exhibit similar antagonistic effects on the performance of Polymer B. The results for the quats (NOxC-2, NOxC-3 and NOxC-4) do not show that molecular weight influences the compatibility of these biocides with Polymer B. Further studies would be required to validate this conclusion. The data in Figure 4 also show that increasing the quat biocide concentration from 1.0 to 2.5 ppm, results in an approximate three- (3) fold reduction in calcium phosphate inhibition values. Based on the performance data presented in Figure 4, it is clear that nitrogen containing biocides (the quats) interact much more strongly with calcium phosphate inhibiting polymer than the phosphorus containing biocide (THPS). Figure 5 presents results on the effect of varying concentration of a polyquat biocide (NOxC-5) for Polymer A and Polymer B at a fixed calcium phosphate supersaturation. It can be seen that NOxC-5 exerts a marked antagonistic influence on the performance of Polymer A and Polymer B. For example, ‘% inhibition’ values obtained in the presence of 0.25 ppm Polymer A and Polymer B are 60 and 85% respectively, compared to >98% obtained in the absence of biocide. It should be noted that increasing the NOxC-5 concentration from 0.25 to 0.50 ppm results in only a 35% decrease in inhibition for Polymer B compared to a 70% decrease in inhibition value for Polymer A. This suggests that the terpolymer (Polymer B) is more tolerant to NOxC-5 than the copolymer (Polymer A). The effect of NOxC-5 at a 0.5 ppm concentration on the performance of several commercial polymers containing varying functional groups was also investigated. Figure 6 presents comparative performance data for these polymers. It is evident from the inhibition data that polymer performance strongly depends on the nature of the comonomers and/or ionic charge of the functional groups present in the polymer. For

6

example, polymers containing three (3) monomer groups perform better than polymers containing only two (2) monomer groups. It is important to note that similar antagonistic effect of cationic flocculant has been reported on the performance of calcium phosphate2 and calcium phosphonate inhibiting polymers.15 The use of biodispersants in conjunction with biocides to control the biofilm formation and deposition of biomass on heat exchanger is well known. In order to understand the interaction of biodispersants with deposit control polymers, a series of calcium phosphate inhibition experiments was carried out under standard test conditions. We evaluated the impact of two (2) biodispersants that contain some charged compounds. However, non-ionic biodispersants were not included in this study. Figure 7 illustrates the results of tests on two biodispersants (i.e., NOxBD-1 and NOxBD-2). It is evident that the presence of biodispersants in calcium phosphate supersaturated solutions has a marked effect on the performance of polymers. Figure 7 also shows that the performance of polymers depends upon biodispersant concentration. For example, at low concentrations (i.e., 1 ppm), both biodispersants do not exhibit any antagonistic effect on polymer performance. However, increasing the NOxBD-1 and NOxBD-2 concentration by a factor of 10 results in an approximate 30 to 40% reduction in calcium phosphate inhibition values. It is interesting to note that NOxC-5 at 0.5 ppm causes a similar dramatic reduction in calcium phosphate inhibition performance as observed with 10 ppm of NOxBD-1 and NOxBD-2. The results presented in Figure 7 clearly show that biodispersants also exhibit an antagonistic effect on polymer performance. In summary, to ensure better overall performance of the system, factors such as polymer types, polymer–biocide and polymer-biodispersant interactions, biocide type, and biocide charge should be carefully evaluated in the selection of formulation additives. Particulate Matter Dispersion Fouling, as opposed to scaling, is the deposition of solids that are normally in suspension in the recirculating water. Most suspended solids are in the form of colloids. Fouling can be of two types: natural and artificial. Natural fouling involves materials that exist in the system as a result of factors external to the system. These could be silt, mud, clay, organics, sand, iron, and debris. Artificial fouling is caused more by the system characteristics, such as corrosion products, clarifier carry-over, aluminum and iron phosphate, and microbiological growth. The control of suspended matter can be done mechanically, chemically, or by a combination of mechanical and chemical means. Chemical control is best achieved by using dispersants. Because iron is generally considered to be one of the cooling water treatment industry’s most troublesome problems, iron oxide dispersion testing is typically used to compare the performance of dispersants. Anionic polymers are known to exhibit good dispersancy property and are believed to function by increasing the negative charge on solid particles. In addition, various factors such as pH, temperature, settling time, particle size, water chemistry, type and concentration of impurities, and treatment chemicals are known to affect the dispersancy power of the polymer.

7

The interaction of both oxidizing and non-oxidizing biocides with deposit control polymers was evaluated by carrying out a series of experiments under standard iron oxide dispersancy test conditions. Figure 8 details the influence of oxidizing biocides (Ox-1 and Ox-2) such as chlorine and bromochlorine and four non-oxidizing biocides (i.e., NOxC-1 to NOxC-4) on the performance of Polymer B. Figure 8 shows the addition of 0.5 to 5 ppm of oxidizing and non-oxidizing biocides does not show any significant effect on the performance of Polymer B. Figure 8 also clearly shows that under the test conditions employed, polymer-biocide interactions do not play a major role in the overall iron oxide dispersant performance. The effect of low levels of non-oxidizing cationic biocides on the performance of Polymer B was also investigated. The results are presented in Figure 9. The presence of 0.1 and 1 ppm THPS had a negligible effect. Further the presence of 0.1 ppm of a quat (i.e., NOxC-2, NOxC-3, and NOxC-4) or biodispersant NOxBD-1 had a relatively low adverse impact (<10% reduction) on the dispersancy power of Polymer B. However, a notable decrease (>10%) in the dispersancy power of Polymer B was caused by the presence of a 0.1 ppm or higher concentration of either the poly quat (NOxC-5) or the NOxBD-2. A similar adverse effect occurred with a 1-ppm concentration of any of the quats (NOxC-2, NOxC-3, and NOxC-4). In particular, a 0.1 ppm dosage of the poly quat (NOxC-5) caused a marked antagonistic effect (>50% reduction) on Polymer B performance. Based on the dispersancy data for non-polymeric quat biocides presented in Figure 9, NOxC-5 had the strongest adverse effect upon Polymer B performance. Figure 9 also indicates that the biodispersants (NOxBD-1 and NOxBD-2) significantly decrease the dispersancy power of Polymer B.

Summary Polymer performance may be adversely affected by stress factors and changing conditions in water treatment programs. Ancillary products used to control microrganisms are routinely used and may affect polymer performance. The results of this study are based on the experimental conditions discussed earlier and suggest the conclusions below. However, it is recognized that the interaction of polymers with corrosion by-products (resulting from the use of biocides) and metal ion – biocide interactions may adversely influence deposit control polymer performance. Although not incorporated herein, these and other factors are the subject of future studies. These factors include the influence of biocides (and biocide charge) on scalant crystal morphology, the compatibility of biocides with anionic deposit control polymers and other additives, and the impact of biocides on particle (e.g., crystal, clay, corrosion by-product) size. 1. Polymer performance for calcium phosphate inhibition is a critical factor in overall

system control. The incorporation of sulfonic groups in the polymer increases the capability to inhibit calcium phosphate at low dosages. The use of polymers containing acrylic acid, sulfonic acid, and sulfonated styrene (AA:SA:SS) perform better than copolymers tested.

2. Oxidizing biocides had no impact on the performance of calcium phosphate

inhibiting polymers.

8

3. The non-oxidizing biocides that contained no charge group had minimal effect on calcium phosphate inhibition.

4. Among the non-oxidizing biocides with a positive ionic charge, the quaternary

ammonium-chloride biocides caused significant decreases in polymer performance. It could not be determined if the type of substitution of the quat (e.g., benzyl or alkyl groups) made any difference. These positively charged compounds antagonistically interacted with the anionic polymers.

5. The positively charged phosphonium biocide did not appear to interact with the

inhibition of calcium phosphate. 6. Polymer-biocide interactions for non-oxidizing nonionic biocides do not play a major

role in the overall iron oxide dispersant performance. 7. Non-oxidizing cationic-biocides have varying degrees of antagonistic effects on the

dispersancy power of Polymer B. The most pronounced adverse impacts on the dispersancy power of Polymer B are displayed by the poly quat and the biodispersants tested.

Acknowledgments

The authors thank The BFGoodrich Company for support to do conduct the studies and present the results to the AWT 2000 Convention. We also wish to thank our customers and the biocide suppliers who collectively provided guidance, samples, and ideas that contributed to this work.

References 1. J. C. Cowan and D. J. Weintritt, Water-Formed Scale Deposit, Gulf Publishing

Company (1975). 2. Z. Amjad, J. F. Zibrida, and R. W. Zuhl, “Performance of Polymers in Industrial

Water Systems: The Influence of Process Variables,” Materials Performance, 36 (1), p. 32 (Jan-97).

3. W. F. Masler and Z. Amjad, “Advances in the Control of Calcium Phosphonate with a

Novel Polymeric Inhibitor,” Paper No. 11, CORROSION/889, NACE International, Houston, TX (1988)

4. Z. Amjad, “Inhibition of Barium Sulfate Precipitation: Effect of Additives, Solution pH,

and Supersaturation,” Water Treatment, 9, p. 47 (1994) 5. Z. Amjad,”Calcium Dihydrate (Gypsum) Scale Formation on Heat Exchanger

Surfaces: The Influence of Scale Inhibitors,” J. Colloid and Surface Science, 123, 523 (1998).

9

6. L. A. Perez and S. M. Kessler, “Novel Calcium Phosphate Scale Inhibitor,” Chapter 12, Water Soluble Polymers: Solution Properties and Applications, Z. Amjad (Ed.), Plenum Press, New York, NY (1998).

7. R. W. Zuhl, Z. Amjad, and W. F. Masler, “A Novel Polymeric Material for Use in

Minimizing Calcium Phosphate Fouling in Industrial Cooling Water Systems,” Journal of the Cooling Technology Institute, Vol. 8 (2), Cooling Tower Institute, Houston, TX (1987).

8. H. C. Felmming, “Mechanistic Aspects of Reverse Osmosis Membrane Biofouling

and Prevention,” Reverse Osmosis: Membrane Technology, Water Chemistry and Industrial Applications, Chapter 6, p. 163, Z. Amjad (Ed.), Van Nostrand Reinhold, New York, NY (1999).

9. Z. Amjad, “Factors to Consider in Selecting a Dispersant for Industrial Water

Systems.” ULTRAPURE WATER, 16 (7), pp. 17-24 (Sep-99). 10. Z. Amjad, J. F. Zibrida, and R. W. Zuhl, “Effect of Cooling Water Impurities on

Deposit Control Polymer Performance,” Materials Performance, NACE International, Houston, TX, Vol. 39 (5), p. 54 (May-00).

11. J. Howarth and C. Nalepa, “First Field Trials of Single-Feed Liquid Bromine Biocide

for Cooling Towers,” TP-00-09, The Cooling Technology Institute Annual Conference, Jan-31 to Feb-3-2000, Houston, TX (2000).

12. B. L. Downward, T. K. Haack, and R. E. Talbot, "TetrakisHydroxymethyl-

Phosphonium Sulfate (TPHS) – A New Industrial Biocide with Low Environmental Toxicity,” Paper No. 401, CORROSION/97, NACE International, Houston, TX (1997).

13. S. M. Kessler and K. Given, “Halogen Compatible Treatment Programs for Open

Recirculating Cooling Water Systems,” Paper No. 300, CORROSION/99, NACE International, Houston, TX (1999).

14. “Legionellosis Guideline: Best Practices for Control of Legionella,” The Cooling

Technology Institute, Houston, TX (Feb-00). 15. J. A. Wohlever, Z. Amjad, and R. W. Zuhl, “Performance Of Anionic Polymers As

Precipitation Inhibitors For Calcium Phosphonates: The Influence Of Cationic Polyelectrolytes,” Advances in Crystal Growth Inhibition Technologies, Kluwer Academic Publishers, New York, NY (2000).

10

Table 1

Deposit Control Polymers Evaluated

Acronym Description Commercial Designation

Polymer A Poly(acrylic acid: sulfonic acid) or Poly(AA:SA)

K-775*

Polymer B Poly(acrylic acid: sulfonic acid: sulfonated styrene) or Poly(AA:SA:SS

K-798*

Polymer C Poly(acrylic acid) or PAA K-752* Polymer D Poly(acrylic acid: sulfonic acid: non ionic)

or Poly(AA:SA:NI) Competitive Terpolymer

Polymer E Poly(acrylic acid: sulfonic styrene) or Poly(AA:SS)

Competitive Copolymer

* A Carbosperse™ (formerly Good-Rite) K-700 polymer supplied by Lubrizol

Advanced Materials, Inc. (formerly BFGoodrich Performance Materials).

Figure 1 pH-stat Apparatus Used in Calcium Phosphate Inhibition Experiments

11

NC C C NH2

Br

Br O

H S

H S

H2C N C SNa

H2C N C SNa

NO2

CH2OH

HOH2C C CH2OH

OHC CH2 CH2 CHOCH2

Table 2

Biocides Evaluated

Acronym Generic Description Chemical Name

Chemical Composition or Structure

Ox-1

NaOCl

Sodium hypochlorite

NaOCl

Ox-2

BrCl

Bromochlorine

BrCl

NOx-1

DBPNA

2,2 Dibromo-3-

nitrilopropionamide

NOx-2

Dithiocarbamate

blend

Disodium ethylene-

bisdithiocarbamate Salt of dimethyl-dithiocarbamate

NOx-3

Gluteraldehyde

Gluteraldehyde

NOx-4

Isothiazoline blend

5-Chloro-2-methyl- 4-isothiazolin-3-one

and 2-Methyl-4-isothiazolin-3-one

NOx-5

Trisnitromethane Tris

(hydroxymethyl) nitromethane

N

C

S

0

CH3Cl

N

C

S

0

CH3

12

CH2OH

HOH2C P CH2OH

CH2OH 2

SO24

N O Cl

R

H3C CH2

CH3

N O Cl

R

H3C CH2

CH3

Table 2 Biocides Evaluated (continued)

Acronym Generic

Description Chemical Name Chemical Composition

or Structure

NOxC-1

THPS

Tetrakishydroxylmethyl phosphonium sulfate

NOxC-2

Quat

Dialklydimethyl

ammonium chloride

NOxC-3

Quat

n-Alkyldimethyl benzyl

ammonium chloride (MW 364)

NOxC-4

Quat

n-Alkyldimethyl benzyl

ammonium chloride (MW 351)

NOxC-5

Poly Quat

Poly Quat

Proprietary

NOxBD-1

Quat

Biodispersant

Proprietary

NOxBD-2

Quat

Biodispersant

Proprietary

CH3

N CH3

C10H21

ClH21C10

13

Figure 2Effect of Oxidizing Biocides (ppm)

on Calcium Phosphate Inhibition by Polymer B

020406080

100

Ox-1 (Cl) Ox-2 (BrCl)Oxidizing Biocides

% C

a/P

Inhi

bitio

n

010100

Figure 3Effect on Non-Oxidizing Biocides (ppm)

on Calcium Phosphate Inhibition by Polymer B

0

20

40

60

80

100

NOx-1 NOx-2 NOx-3 NOx-4 NOx-5

Non- Oxidizing Biocides

% C

a/P

Inhi

bitio

n

052050

Figure 4Effect of Cationic Biocides (ppm)

on Calcium Phosphate Inhibition by Polymer B

020406080

100

NOxC-1 NOxC-2 NOxC-3 NOxC-4

Cationic Biocides

% C

a/P

Inhi

bitio

n

00.512.5

14

Figure 5Effect of NOxC-5 (Poly Quat) on Calcium Phosphate Inhibition

0

20

40

60

80

100

0 0.5 1 1.5 2

Biocide Dosage (ppm)

% C

a/P

Inhi

bitio

n

Polymer BPolymer A

Figure 6Effect of NOxC-5 (ppm)

on Calcium Phosphate Inhibition by Various Polymers

0

20

40

60

80

100

Polymer A Polymer B Polymer C Polymer D Polymer E

Polymers

% C

a/P

Inhi

bitio

n

00.5

Figure 7Effect of Biodispersants (ppm)

on Calcium Phosphate Inhibition by Polymer B

020406080

100

NOxBD-1 NOxBD-2

Biodispersants

% C

a/p

Inhi

bitio

n

01520

15

Figure 8Effect of Various Biocides (ppm)

on Iron Oxide Dispersancy by Polymer B

0

20

40

60

80

100

Ox-1 Ox-2 NOx-1 NOx-2 NOx-3 NOx-4Biocides

% D

ispe

rsan

cy

00.55

Figure 9Effect of Cationic Biocides (ppm)

on Iron Oxide Dispersancy by Polymer B

0

20

40

60

80

100

NOxC-1 NOxC-2 NOxC-3 NOxC-4 NOxC-5 NOxBD-1 NOxBD-2

Cationic Biocides

% D

ispe

rsan

cy

00.11

16

For additional technical information pertaining to Lubrizol’s Carbosperse™ (formerly Good-Rite) K-700 Polymers, please contact us as follows:

Lubrizol Advanced Materials, Inc. 9911 Brecksville Road

Cleveland, OH 44141-3247, U.S.A. Phone: 1-800-380-5397 or 216-447-5000 FAX: 216-447-6315 (USA Customer Service) 216-447-6144 (International Customer Service) 216-447-5238 (Marketing & Technical Service) E-mail: coatings.csr@Lubrizol.com Web Site: www.carbosperse.com

™ Trademark of The Lubrizol Corporation

Oct-2000 (Updated Oct-2007)

The information contained herein is believed to be reliable, but no representations, guarantees or warranties of any kind are made to its accuracy, suitability for particular applications, or the results to be obtained therefrom. The information is based on laboratory work with small-scale equipment and does not necessarily indicate end product performance. Because of the variations in methods, conditions and equipment used commercially in processing these materials, no warranties or guarantees are made as to the suitability of the products for the application disclosed. Full-scale testing and field application performances are the responsibility of the user. Lubrizol Advanced Materials, Inc. shall not be liable for and the customer assumes all risk and liability of any use or handling or any material beyond Lubrizol Advanced Materials Inc.’s direct control. The SELLER MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANT ABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Nothing contained herein is to be considered as permission, recommendation, nor as an inducement to practice any patented invention without permission of the patent owner.

Lubrizol Advanced Materials, Inc. 9911 Brecksville Road, Cleveland, OH 44141, P/216-447-5000, F/216-447-5238

© 2007 The Lubrizol Corporation, all rights reserved.