Effects of carboxylic polyelectrolytes on the growth of calcium carbonate

Journal of Crystal Growth 317 (2011) 70–78

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Effects of carboxylic polyelectrolytes on the growth of calcium carbonate M. Euvrard a,n, A. Martinod b, A. Neville b a b

´, 16, Route de Gray, 25030 Besanc- on, France Institut UTINAM, UMR 6213, Universite´ de Franche-Comte School of Mechanical Engineering, University of Leeds, Leeds LS2 9JT, UK

a r t i c l e i n f o

a b s t r a c t

Article history: Received 6 September 2010 Received in revised form 17 December 2010 Accepted 4 January 2011 Communicated by S. Uda Available online 19 January 2011

In this paper experimental results are reported on the effects of anionic polyelectrolytes (polyaspartate and polymaleic acid) on the formation of calcium carbonate on a metallic substrate. An experimental procedure which permits the in situ and real-time growth of particles in the micrometric range to be followed was used. By using image analysis, the determination of the morphometric parameters of crystals was done. Jointly, an adsorption study of the polyelectrolytes on calcite was conducted to complement the study of the interactions between polyelectrolytes and crystals. It has been shown that polyaspartate (PASP) and polymaleic acid (PMA) may influence the nucleation/growth process of calcium carbonate. At low concentrations (of about 1  10  5 mol dm  3), PMA and PASP reduce the surface coverage of deposits on the substrate by decreasing the number of micron size particles and/or the sizes of mineral. When the polyelectrolytes were added after 10 min of the experiment, they significantly decreased the growth rate of the crystals. Following the adsorption of the polyelectrolytes on the submicron size crystals of calcite complements this research. Langmuir isotherms show that PASP and PMA adsorb on calcite suggesting that the polyelectrolytes may block the active sites of growth of crystals. & 2011 Elsevier B.V. All rights reserved.

Keywords: A1. Adsorption A1. Substrate A2. Growth B1. Calcium carbonate B1. Polymaleic acid B1. Polyaspartate

Supersaturation, the thermodynamic driving force for scale formation, can be expressed by

1. Introduction The build-up of deposits on surfaces is a persistent problem in many industrial operations including desalination, oil and gas recovery. The potential for mineral scale formation continues to be by far the most costly design and operating problem in waterhandling processes. From a design standpoint, the heat transfer area in a multiple stage flash (MSF) plant constitutes about 30% of the total cost, and the fouling tendency may require a 20–25% excess design allowance. This could represent 6% of the unit cost [1–4]. These deposits typically consist of mineral scales (i.e., CaCO3, CaSO4, etc.), corrosion products (i.e.Fe2O3, CuO, etc.), particulate matter (i.e., clay, silt), and microbiological mass. Deposition of these materials on surfaces can lead to loss of system efficiency, overheating, unscheduled shutdown time, and ultimately heat exchanger failures. Due to its low solubility, calcium carbonate is a major salt which leads to the formation of scale on surfaces and in particular in heat exchange systems [5–6]. Calcium carbonate scale forms by the reaction of calcium and carbonate ions in water Ca2 + +CO23  -CaCO3(s)

n

Corresponding author. Tel.: +33 3 81 66 20 45; fax: + 33 3 81 66 55 04. E-mail address: [email protected] (M. Euvrard).

0022-0248/$ - see front matter & 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.jcrysgro.2011.01.006

(1)

0

h

i

h

gCa2 þ Ca2 þ gCO3 2 CO3 2

S¼@

KSP

i11=2 A

ð2Þ

with gCa2+ and [Ca2 + ] are the activity coefficient and concentration of calcium ions, gCO3 2 and ½CO3 2  are the activity coefficient and concentration of carbonate ions, and KSP is the solubility product. When S41, water is supersaturated and is therefore capable of forming calcium carbonate solids either as suspended particles in the solution or as a deposit on a surface that is in contact with the water [5]. Several factors can enhance the formation of scale on surfaces as compared with the formation of solid in the bulk solution phase. If the surface is heated, the higher temperature of the surface boosts the rates of both nucleation and crystal growth and increases the supersaturation, which is the thermodynamic driving force for both processes. Locally higher supersaturation can also be realized when the surface selectively adsorbs species from solution. Moreover, the energetics of nucleation can favor the heterogeneous nucleation on surfaces as compared with homogeneous nucleation in the bulk fluid; heterogeneous nucleation proceeds at a faster rate than homogeneous nucleation for a solution of a given S [5]. The appearance and persistence of three anhydrous crystalline polymorphs of calcium carbonate (calcite, aragonite, and vaterite) are highly sensitive to the local conditions of precipitation: pH, temperature, supersaturation, and the presence of additives and

M. Euvrard et al. / Journal of Crystal Growth 317 (2011) 70–78

impurities [6–10]. The most commonly formed CaCO3 polymorph is calcite which is often thermodynamically more stable than aragonite and vaterite at ambient temperatures and pressures [6]. To simulate scaling, the synthesis of calcium carbonate, one of the most abundant minerals, has been intensively investigated. Interestingly, colloids were used as curved templates or nuclei for the growth of scaling minerals [11–15]. Moreover, electrochemical methods have been investigated for several years. A metallic surface is cathodically polarized at a negative potential which accelerates the reduction of dioxygen reaction at the surface and produces an excess of hydroxyl ions. The associated increase in pH leads to the precipitation of calcium carbonate on the surface of the working electrode as the solubility is highly excessed locally [16–20]. To modify the crystallization of calcium carbonate, chemical [21–26], and physical [27–29] treatments are developed. The induced modifications can be divided into three main categories: those that affect solubility, those that alter the growth mechanism of crystals, and those that change the potential of a surface to foul. Scale prevention is often achieved by use of scale additives that are added in threshold amounts (ppm). Antiscalants are typically polyelectrolytes such as polyphosphonates and polyphosphates [30–35] with reported optimal molecular weights in the range 1000–3500. Some phosphorous compounds are wellknown to inhibit the development of crystals but they may cause severe damage to the environment such as eutrophication [36]. Increasing environmental concerns and discharge limitations have imposed additional challenges in treating process waters. Therefore, the discovery and successful application of chemical additives for the control of scale and corrosion that have mild environmental impact have gradually become the focus of several research efforts [37–38]. One of the current challenges is to understand how environmental-friendly additives without phosphorous influence the crystallization process of calcium carbonate. It has been suggested that antiscalants adsorb onto formed crystals or associate/complex with incipient nuclei (or crystals), thereby inhibiting mineral salt crystallization [21]. This delay, which is referred to as the crystallization ‘‘induction time’’, occurs at remarkably low ‘‘threshold dosages’’ in the order of 1–10 ppm. Although it is accepted that antiscalants retard crystallization and reduce scale formation, there has been not much direct evidence of antiscalant impact on the crystals on a surface in situ and in real time. In the present study, we report on the optical characterization of the development of calcium carbonate crystals on metallic surfaces in situ and in real time and on the effect of non phosporous polyelectrolytes on the crystals: polymaleic acid (PMA) and polyaspartate (PASP). The electrochemical and optical technique presented in this paper allows the crystallization and the effects of additives at the solid–liquid interface to be probed. The change in shape and size of crystals were quantified as well as the coverage surface. X-ray diffraction after the tests gives complementary information. This research completes a preliminary study that was done on PASP [39]. Moreover the adsorptions of PMA and PASP on colloidal calcite were studied in order to assess the mechanisms by which the additives act.

71

Sea [40]. It was prepared as follows: two brines were prepared and mixed 50:50 just before the experiments with composition reported in Table 1. The reactants were purchased from Aldrich. Sodium polyaspartate (PASP) and polymaleic acid (PMA) were investigated. The polymeric additives used in this study are commercial products; PASP was purchased by Champion Technologies (the commercial name is PASP:T/1120) and PMA by BWA (the commercial name is PMA DP 5006). The main chemical characteristics are presented in Table 2. The concentrations of the polyelectrolyte solution were low: 7.6  10  3 mol/dm  3 per unit of monomer for PASP solution and 9.5  10  3 mol/dm  3 for PMA solution. The initial pH of PMA solution was of 2.7 and for PASP 7.9; for the adsorption experiments the pH values were adjusted to 8 and 10.5 in order to get pH close to that of the bulk of the solution and to the predicted pH near the surface of crystallization. For the crystallization experiments, the chosen concentrations were 1 and 4 ppm; the polyelectrolytes were added at the start of the experiment or after 10 min of crystallization in order to study their effects on the growth of crystals. To study the adsorption of the polyelectrolytes on calcium carbonate, calcite was used. It was purchased from Solvay (SOCAL 31) which is a synthetic ultrafine precipitated calcium carbonate. The content of the reactant is 98.9% without drying; the mean particle diameter is 70 nm and the specific area (BET) is 20 m2/g. 2.2. Crystallization and morphology of calcium carbonate In order to promote the formation of crystals on a substrate, an electrochemical process was developed. The procedure consists of polarizing an electrode to stimulate the reduction of oxygen as follows: O2 +2H2O + 4e  -4OH 

(3)

The production of hydroxyl ions in the vicinity of the electrode has been shown to increase the local pH [39] by inducing the precipitation of calcium carbonate according to a two-step chemical reaction: HCO3  þ OH -CO3 2 þ H2 O

ð4Þ

Ca2 þ þ CO3 2 -CaCO3ðsÞ

ð5Þ

Table 1 Composition of the reference solution.

Na + Ca2 + Mg2 + K+ Sr2 + HCO3  Cl  pH

Brine 1 (mol/L)

Brine 2 (mol/L)

0.110 0.026 0.06 0.03 0.001 0 0.145

0.110 0 0 0 0 0.02 0.108 7.8

Table 2 Properties of the polyelectrolytes. Polyelectrolyte Details

2. Experimental

Total organic carbon (mg/L)

Molar concentration (monomer unity) 10  3 mol/L

pH

7.6

7.9

9.5

2.7

2.1. Chemicals PASP

A synthetic aqueous solution which presents a composition close to that of the water extracted from the oil well in North

PMA

Sodium poly-a- 366 b-D,L-aspartate Polymaleic acid 430

72

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The interfacial pH during the reduction of dissolved oxygen in a submerged impinging jet cell has already been measured by Deslouis et al. [41]. For the two plateaus of oxygen reduction, the values were 10.4 and 10.7, very close to the calculated ones of 10.36 and 10.66. The electrochemical cell fully described previously [42,43] integrates three electrodes: the working electrode is a removable plug comprising a circular stainless steel electrode composed of Stainless steel 316L (69% of Fe/18% of Cr/10% of Ni and 3% of Mo). The counter electrode is a window that was made electrically conducting by deposition of tin oxide and the reference electrode

40

SF ¼ P2 =ð4pAÞ

Surface coverage (%)

35

ð6Þ

with P perimeter and A00 area of the crystals. The values of shape factors range from 0 to 1. If SF¼ 1, the crystal is a circle, if SF is close to 0, it resembles a rod. The mean characteristics of crystals and their statistical distributions were calculated. Because image analysis allows the characterization of each crystal, a statistical analysis was performed. For a particular time of polarization, the total number of crystals was determined. Size distributions were calculated and then the percentage of crystals corresponding to each class was given. Each value (percentage for a class) was represented by a point.

30 25 20 15 10 5 0

is a silver wire that was pretreated with a diluted solution of hydrochloric acid (Ag/AgCl electrode). The optical and measurement setup was already presented [42,43]; the video assembly contained a  20 long working distance objective lens, a video tube, a lighting system, a camera (SONY SSC-DC38P), an image monitor (SONY PVM 1450), and a recorder (SONY SL-UE 710B). The magnification power (  1000) was high enough to observe micron size particles on the working electrode. The video camera focused on the center of the electrode to avoid any edge effects. A professional image analysis package (Esilab—Arie s, France) was used for image capture and analysis. The crystals were imaged at different times and several parameters were determined, diameter and shape factor SF of the particles which is defined in Eq. (6) and surface coverage S(t)(%) of the sheets

Reference 0

1000

PMA 1ppm

2000 time (s)

PASP 1ppm 3000

4000

Fig. 1. Surface coverage by calcium carbonate in presence of 1 ppm of polyelectrolytes.

2.3. Adsorption of the polyelectrolytes on calcite The adsorption of polyelectrolytes on calcium carbonate was determined by the depletion of polymer from the solution. The polyelectrolyte solutions were prepared at different concentrations using deionized water and adjusted to pH 8.070.1 or 10.570.1 with

Fig. 2. SEM pictures of crystals after 60 min of experiment—reference (a), in presence of 1 ppm of PMA (b) and 1 ppm of PASP (c).

M. Euvrard et al. / Journal of Crystal Growth 317 (2011) 70–78

50

45 40 35

10 minutes

45

10 minutes

20 minutes 40 minutes

40

20 minutes 40 minutes

35 crystals (%)

crystals (%)

30 25 20 15

30 25 20 15

10

10

05 00

73

05 0

5

10 15 size (μm)

20

25

00

0

5

10 15 size (μm)

20

25

50 45 40

crystals (%)

35 30 25 20

10 minutes 20 minutes 40 minutes

15 10 05 00

0

5

15 10 size (μm)

20

25

Fig. 3. Percentage of crystals according to size classes—reference (a), in presence of 1 ppm of PMA (b) and 1 ppm of PASP (c).

sodium hydroxide. Then, the calcite suspensions (at maximum 5% w/w) were prepared by dispersing calcium carbonate in the solution using a high disk disperser. They were stirred for 24 h and the supernatant was separated by centrifugation. Then 10 mL of pure hydrochloric acid were added at a volume of 5 mL of supernatant and nitrogen gas was bubbled though the solution for 10 min in order to remove CO2. The initial and final concentrations of polyelectrolytes in the solution were measured with a total carbon analyzer (Shimadzu 5050). The amount of polyelectrolyte that had been lost through on the separated calcium carbonate was calculated from the difference between the initial and final concentrations. Moreover, the concentrations of calcium ions present in the solution after centrifugation of the samples were quantified by by atomic absorption spectroscopy (AAS, 50B spectra, Varian).

3. Results and discussion 3.1. Effects of polyelectrolytes on the crystallization of calcium carbonate In reference water, the surface coverage of the substrate increased as a function of time of polarization; after 60 min of experiment, it was of 33% as shown in Fig. 1. The number of crystals was 130 ( 715) per 600 mm2. As soon as the electrochemical potential was applied, numerous small crystals appeared spontaneously on the surface of the electrode. Then, they grew homogeneously as shown in Fig. 2 which presents SEM image of the sheet after 60 min of experiment.

74

M. Euvrard et al. / Journal of Crystal Growth 317 (2011) 70–78

The distribution of crystals presents one mode with a Gaussian distribution and the shifting of the curve between 10 and 40 min was due to the growth of crystals (Fig. 3). After 40 min of

crystallization, the distribution of the crystals is larger. The deposit was mainly composed of calcite as shown on—X ray diffraction pattern (Fig. 4a).

Lin (Counts)

Calcite, syn

Lin (Counts)

2-Theta - Scale

2-Theta - Scale

Fig. 4. X-Ray diffraction pattern of the crystals—reference (a), in presence of 1 ppm of PMA (b) and 1 ppm of PASP (c).

75

Lin (Counts)

M. Euvrard et al. / Journal of Crystal Growth 317 (2011) 70–78

2-Theta - Scale

Fig. 4. (Continued)

40

Table 3 Mean morphometric characteristics of crystals in presence of PMA and PASP added at the start of the experiment.

300 600 1200 2400

Mean diameter (mm)

Shape factor

No additive

PASP 1 ppm

PMA 1 ppm

No additive

PASP 1 ppm

PMA 1 ppm

4.1 5.3 7.5 11.6

3.7 5.1 7.2 10.4

3.7 5.3 7.3 11.2

0.5 0.5 0.5 0.5

0.3 0.3 0.3 0.3

0.4 0.5 0.5 0.5

Experiments were carried with different concentrations of polyelectrolytes they were added at the start of the experiment or after 10 min of crystallization.

3.1.1. Polyelectrolytes added at the start of the experiment PASP and PMA added at a concentration of 1 ppm induced a decrease of the deposit of calcium carbonate (Fig. 1). The effects of PASP and PMA were similar; they promoted a decrease in the surface coverage which was about 23% after 60 min of experiment. It was due to a decrease of the number of micron size crystals: in the presence of PASP it was around 90 (710) per 600 mm2 and in presence PMA, it was around 100 (710) per 600 mm2. Nevertheless, image analysis indicates that the mean diameters of the crystals were close to those formed from the reference water (Table 3). As in the reference solution, the distribution of crystals presents one mode with a Gaussian distribution and the shifting of the curve between 10 and 40 min was due to the growth of crystals (Fig. 3); the values were close to those for the reference solution. The shape factors of crystals were lower in presence of PASP; it was due to a

Surface coverage (%)

Time (s)

Reference

35

PMA 4ppm

PASP 4ppm

30 25 20 15 10 5 0

0

1000

2000 time (s)

3000

4000

Fig. 5. Surface coverage by calcium carbonate in presence of 4 ppm of polyelectrolytes added 10 min after the start of the experiment.

light distortion of crystals. The crystals appearances (Fig. 2) and X-ray spectra were similar to this of the reference (Fig. 4b and c). These first experiments suggested that PASP and PMA may act by reducing the crystallization of the salt during the first step of crystallization. The presence of the additives at a concentration of 1 ppm may quickly block the nucleation or the development of some submicron size crystals which were larger detectable. Nevertheless, the other crystals grew as in the reference solution. At a concentration of 4 ppm, the effects of PASP and PMA on calcium carbonate crystallogenesis increased strongly. In the presence of PASP, no more crystals were quantified by optical microscopy during the experiment indicating that the detectable

76

M. Euvrard et al. / Journal of Crystal Growth 317 (2011) 70–78

surface coverage is less than 1%. In the presence of PMA, a few crystals (around 40) were quantified at the surface of the metallic surface by the visualization technique. They did not grow during the experiment; so, the coverage of the working electrode was less than 1% after 60 min. The concentrations of polyelectrolytes in solution were low, therefore the observed inhibition effect in not due to a decrease of the solution supersaturation because of the Ca2 + sequestration by the polyelectrolytes but may be attributed to an extensive blocking of the active growth sites on the crystals.

3.1.2. Polyelectrolytes added after 10 min of crystallization To study the effect of the polyelectrolytes on the growth of crystals, 4 ppm of PASP and PMA were added to the reference solution after 10 min of crystallization.

45

45

10 minutes 20 minutes 40 minutes

40

40

35

35

30

30 crystals (%)

crystals (%)

As soon as PMA was added, the surface coverage did not change any further during the experiment as shown in Fig. 5. Statistical analysis complements these results (Fig. 6): there was no change of the size distribution after the addition of PMA. The kinetics of adsorption of the polyelectrolyte seems quick enough and sufficient to block the growth sites of calcite. PASP did not block totally the growth of crystals as PMA but a delay of the surface coverage was observed too (Fig. 5). Both categories of crystals were observed as presented in Fig. 6: almost crystals did not change of size whereas a few grew. The likely explanation for the observed significant retardation of crystal growth in presence of PASP and PMA is related to their adsorption at the crystal surface; that is why the interaction between polyelectrolytes and calcite was studied.

25 20

25 20

15

15

10

10

05

05

00

5

10

15 size (μm)

20

25

00

10 minutes 20 minutes 40 minutes

0

5

10

15 size (μm)

20

25

50 10 minutes 20 minutes 40 minutes

45 40

crystals (%)

35 30 25 20 15 10 05 00

0

5

10 15 size (μm)

20

25

Fig. 6. Percentage of crystals according to size classes—reference (a), in presence of 4 ppm of PMA (b) and 4 ppm of PASP (c) added after 10 min of crystallization.

M. Euvrard et al. / Journal of Crystal Growth 317 (2011) 70–78

25.0

Table 4 Constants in function from Langmuir isotherm.

20.0 τ (mg.g-1)

77

Kads (dm  3 mg  1)

r2

1/t ¼1/tmax + 1/(KadstmaxCe)

(mg g  1) 14 25 28 25

o0.01 o0.01 o0.01 o0.01

0.91 0.93 0.96 0.93

1/t ¼0.07 +31.5  1/Ce 1/t ¼0.04 +28.9  1/Ce 1/t ¼0.03 +14.4  1/Ce 1/t ¼0.04 +12.05  1/Ce

smax

15.0

PMA pH¼9.2 PMA pH¼10.5 PASP pH¼ 9.2 PASP pH¼ 10.5

10.0 5.0 0.0

0

100

200

300

400 500 Ce (mg/L)

600

700

800

900

Fig. 7. Adsorption of PASP on calcite at pH 8 and 10.

16.0 14.0

τ (mg.g-1)

12.0 10.0 8.0 6.0 4.0 2.0 0.0

0

200

400

600 Ce (mg/L)

800

1000

1200

Fig. 8. Adsorption of PMA on calcite at pH 8 and 10.

From the plot of 1/t versus 1/Ce, the value of tmax was calculated (Table 4). At pH 8, it was of 14 ( 73) mg/g for PMA and 25 ( 73) mg/g for PASP. At pH 10.5, the values were similar for both polyelectrolytes. At pH 9.2 and 10.5, the calcite surface presents low charge [44]; it may justify that the adsorbed amounts were close. The values of tmax compared to the overall amount of PASP and PMA seem to indicate that the molecules are not incorporated into the crystal matrix and are partially covering the calcium carbonate surface. It must be noted that the adsorbed amounts of polyelectrolytes were widely higher than those which were used for the crystallization experiments. These results suggest that carboxylate functional groups adsorb on the calcite crystals occupying cationic sites. The data indicate that the affinity for calcite is slightly higher for PASP than for PMA. As PMA present more carboxylate group than PASP, the blocking of active sites may be efficient at lower concentrations of PMA than of PASP. This explanation may justify the results that were obtained when the polyelectrolytes were added after 10 min of crystallization.

3.2. Adsorption of the polyelectrolytes on calcite

4. Conclusions

Two initial pH were chosen to study the amount of the polyelectrolytes retained on the calcite particles: 8.0 and 10.5. The addition of calcium carbonate to the solution at pH 10.5 70.1 did not lead to a modification of pH. For a suspension at 5% (w/w), the concentration of calcium ions in the control sample (water and calcium carbonate) after 24 h was of 1.5 70.3  10  3 mol L  1; the maximum dissolution of calcium carbonate was 0.3%. The concentrations of calcium ions in the solutions containing PASP or PMA were similar to this of control sample. These results indicate that in presence of additive, there is no precipitation of calcium salts. The addition of calcium carbonate to the solution at pH 8.0 70.1 led to a modification of pH due to the dissolution of calcium carbonate; whatever the samples, it was of 9.1 70.2 for a suspension at 5% (w/w). The concentrations of calcium ions in the suspensions were similar to those quantified at pH 10.5. The results of the adsorption show that there is an increase of the amounts of the polyelectrolytes on calcite with increasing polymers concentration and then a plateau is reached as shown in Figs. 7 and 8. To estimate the fraction of PASP and PMA on the surface of the crystals, the adsorption isotherms were analyzed by using the Langmuir model as presented in

Polyaspartate and polymaleic acid affect the crystallization of calcium carbonate at low concentrations. They lead to modifications in the morphology and size of the mineral. At low concentrations (of about 1  10  5 mol dm  3), PMA and PASP reduce the surface coverage of deposits on the substrate by decreasing the number of the particles or/and the sizes of mineral. When the polyelectrolytes were added after 10 min of experiment, they highly decreased the growth of crystals. So, these polyelectrolytes interact on the crystallization of calcium carbonate and can modify the ongoing processes. The study of the adsorption of the polyelectrolytes on submicronic crystals of calcite points out that they may adsorb on the mineral at pH 8 and 10.5; the results suggest that carboxylate functions adsorb on the calcite crystals occupying cationic sites. Many further studies will be required in order to understand the effects of scaling treatments in relation with the structures and concentrations of macromolecules, with the physico-chemical conditions such as the composition of water.

t ¼ tmax KL Ce=ð1 þ KL CeÞ

ð7Þ

t is the amount of polyelectrolyte retained on calcite, tmax is the macromolecule amount at monolayer adsorption, KL is the related to the activities of the solid surface sites and polymer molecules in solution and absorbed on the solid surface, Ce is the solution equilibrium concentration of the polyelectrolyte.

References [1] Z. Amjad, Advances in Crystal Growth, Inhibition Technologies, Plenum Press, New York, 2000. [2] K.D. Demadis, E. Mavredaki, A. Stathoulopoulou, E. Neofotistou, C. Mantzaridis, Desalination 213 (1–3) (2007) 38. [3] T. Chen, A. Neville, M. Yuan, J. Pet. Sci. Eng. 46 (2005) 185. [4] J.S. Gil, Desalination 124 (1999) 43. [5] W. Stumm, J.J. Morgan, Aquatic Chemistry, Wiley, New York, 1996. [6] J.W. Mullin, Crystallization, Butterworth-Heinemann, Oxford, 1993. [7] Q. Yu, H.-D. Ou, R.-Q. Song, A.-W. Xu, J. Cryst. Growth 286 (2006) 178. [8] S. Ghizellaoui, M. Euvrard, Desalination 220 (2008) 394. [9] N. Vdovic´, D. Kralj, Colloids Surf. A 161 (2000) 499. [10] H. Colfen, J. Colloid Interface Sci. 8 (1) (2003) 23.

78

M. Euvrard et al. / Journal of Crystal Growth 317 (2011) 70–78

[11] M. Reddy, G.H. Nancollas, J. Colloı¨d, Interface Sci. 36 (1971) 166. [12] J. Katz, K. Parsiegla, Miner. Scale Form. Inhib. [Proc. Am. Chem. Soc. Symp.], Meet. D (1995) 11. [13] J. Katz, M. Reick, R. Herzog, K. Parsiegla, Langmuir 9 (1993) 1423. [14] M.G. Lioliou, C.A. Paraskeva, P.G. Koutsoukos, A.C. Payatakes, J. Colloid Interface Sci. 308 (2) (2007) 421. [15] V.L. Borodin, I.V. Nefedova, J.Cryst. Growth 275 (1–2) (2005) 633. [16] J. Ledion, P. Leroy, J.P. Labbe, TSM L’eau (1985) 323. [17] A. Neville., T. Hodgkiess., A.P. Morizot, J. Appl. Electrochem. 29 (4) (1999) 455. [18] M. Euvrard, F. Membrey, C. Filiatre, A. Foissy, J. Cryst. Growth 265 (2004) 322. [19] P. Kjellin, K. Holmberg, M. Nyde´n, Colloids Surf. A 194 (1–3) (2001) 49–55. [20] J. Marı´n-Cruz, E. Garcı´a-Figueroa, M. Miranda-Herna´ndez, I. Gonza´lez, Water Res. 38 (1) (2004) 173. [21] L.F. Greenlee, F. Testa, D.F. Lawler, B.D. Freeman, P. Moulin, Water Res. 44 (2010) 2957. [22] A. Martinod, M. Euvrard, A. Foissy, A. Neville, Desalination 220 (1–3) (2008) 345. [23] Ch. Tzotzi, T. Pahiadaki, S.G. Yiantsios, A.J. Karabelas, N. Andritsos, J. Membr. Sci. 296 (1–2) (2007) 171. [24] A. Jada, A. Verraes, Colloids Surf. A 219 (1–3) (2003) 7. [25] M.M. Reddy, J. Cryst. Growth 41 (2) (1977) 287. [26] L.A. Gower, D.A. Tirrell, J. Cryst. Growth 1–2 (1998) 153. [27] S.A. Parsons, B.-L. Wang, S.J. Judd, T. Stephenson, Water Res. 31 (2) (1997) 339.

[28] C. Gabrielli, R. Jaouhari, G. Maurin, M. Keddam, Water Res. 35 (13) (2001) 3249. [29] V. Tantayakom, T. Sreethawong, H. Scott Fogler, F.F. de Moraes, S. Chavadej, J. Colloid Interface Sci. 284 (2005) 57. [30] R. Ketrane, B. Saidani, O. Gil, L. Leleyter, F. Baraud, Desalination 249 (3) (2009) 1397. [31] M.B. Tomson, J. Cryst. Growth 62 (1) (1983) 106. [32] N. Abdel-Aal, K. Sawada, J. Cryst. Growth 256 (1–2) (2003) 188. [33] J.-Y. Gal, J.-C. Bollinger, H. Tolosa, N. Gache, Talanta 43 (9) (1996) 1497. [34] B. Nowack, Water Res. 37 (11) (2003) 2533. [35] A.G. Xyla, J. Mikroyannidis, P.G. Koutsoukos, J. Colloid Interface Sci. 153 (2) (1992) 537. ¨ [36] S. Lattemann, T. Hopner, Desalination 220 (2008) 1. [37] A. Martinod, A. Neville, M. Euvrad, K. Sorbie, Chem. Eng. Sci. 64 (10) (2009) 2413. [38] D.-J. Choi, S.-J. You, J.-G. Kim, Mater. Sci. Eng. A 335 (1–2) (2002) 228. [39] A. Martinod, A. Neville, M. Euvrard, Desalination Water Treat. 7 (2009) 86. [40] K. Ziegler, M.L. Coteman, R.J. Howard, Appl. Geochem. 16 (2001) 609. [41] C. Deslouis, I. Frateur, G. Maurin, B. Tribollet, J. Appl. Electrochem. 27 (1997) 482. [42] M. Euvrard, C. Filiatre, E. Crausaz, J. Cryst. Growth 216 (2000) 466. [43] M. Euvrard, F. Membrey, C. Filiatre, C. Pignolet, A. Foissy, J. Cryst. Growth 291 (2006) 428. [44] R. Eriksson, J. Merta, J.B. Rosenholm, J. Colloid Interface Sci. 313 (1) (2007) 184.