Characterization of the Corrosive Action of Mineral Waters from Thermal Sources: A Case Study at Azores Archipelago, Portugal
Abstract
:1. Introduction
2. Experimental
2.1. Determination of the Langelier Saturation Index (LSI)
2.2. Determination of the Ryznar Stability Index (RSI)
2.3. Determination of the Puckorius Scaling Index (PSI)
2.4. Determination of the Larson–Skold Index (LI)
2.5. Electrochemical Characterization
3. Results and Discussion
3.1. Estimation of the Corrosive Action of the Natural Waters Using Stability and Scaling Indexes
Water Source | T/°C | pH | κ/μS·cm−1 | TDS/mg·L−1 | [Ca2+]/mg·L−1 | [SO42−]/mg·L−1 | [Cl−]/mg·L−1 | [HCO3−]/mg·L−1 | LSI | RSI | PSI | LI |
---|---|---|---|---|---|---|---|---|---|---|---|---|
AM9 | 99.5 | 7.71 | 2010 | 1274 | 1.4 | 63 | 297.1 | 771 | 0.50 | 6.60 | 5.60 | 0.80 |
AM10 | 98.8 | 7.06 | 2350 | 1655 | 1.2 | 297 | 303.9 | 679.5 | −0.30 | 7.60 | 6.00 | 1.30 |
AM13 | 98.5 | 5.76 | 715 | 709 | 10 | 223 | 23.8 | 12.8 | −2.30 | 10.40 | 10.00 | 25.30 |
AM35 | 98 | 7.29 | 1785 | 1146 | 2.2 | 64 | 219 | 706.4 | 0.30 | 6.80 | 5.40 | 0.60 |
AM39 | 70 | 5.37 | 301 | 539 | 6.6 | 31 | 22.7 | 89.1 | −2.50 | 10.40 | 8.40 | 0.90 |
Water Source | T/°C | pH | κ/μS·cm−1 | TDS/mg·L−1 | [Ca2+]/mg·L−1 | [SO42−]/mg·L−1 | [Cl−]/mg·L−1 | [HCO3−]/mg·L−1 | LSI | RSI | PSI | LI |
---|---|---|---|---|---|---|---|---|---|---|---|---|
AM1 | 21.1 | 5.27 | 410 | 814 | 9.6 | 46 | 22.7 | 120.8 | −3.20 | 11.70 | 9.40 | 0.60 |
AM2 | 34.4 | 5.33 | 365 | 619 | 11 | 41 | 19.9 | 159.2 | −2.70 | 10.70 | 8.30 | 0.50 |
AM3 | 75.1 | 6.16 | 515 | 416 | 8.9 | 7.5 | 36.9 | 256.8 | −1.00 | 8.20 | 6.30 | 0.30 |
AM4 | 15.9 | 5.09 | 301 | 840.1 | 8.2 | 18 | 20.9 | 92.1 | −3.70 | 12.50 | 10.10 | 0.60 |
AM5 | 15.6 | 4.95 | 306 | 697.3 | 11 | 33 | 19.5 | 74.4 | −3.80 | 12.50 | 10.20 | 1.00 |
AM6 | 16.2 | 4.99 | 210 | 767.9 | 11 | 32 | 24.5 | 72 | −3.80 | 12.50 | 10.20 | 1.10 |
AM7 | 41.3 | 5.57 | 522 | 738.7 | 11 | 13 | 59.3 | 226.9 | −2.20 | 10.00 | 7.50 | 0.50 |
AM8 | 40.4 | 5.58 | 519 | 728.5 | 9.5 | 11 | 65.3 | 228.1 | −2.30 | 10.10 | 7.70 | 0.60 |
AM11 | 59.5 | 6.21 | 1356 | 953 | 28 | 16 | 76.3 | 779.6 | −0.30 | 6.80 | 4.20 | 0.20 |
AM12 | 59.3 | 6.24 | 1271 | 939.8 | 30 | 18 | 76.3 | 767.4 | −0.30 | 6.70 | 4.20 | 0.20 |
AM14 | 17.5 | 6.77 | 190 | 159.1 | 4.5 | 6.2 | 18.5 | 80.5 | −2.20 | 11.20 | 10.60 | 0.50 |
AM15 | 41.3 | 6.02 | 1459 | 1117 | 28 | 14 | 91.9 | 786.9 | −0.80 | 7.70 | 4.90 | 0.20 |
AM16 | 42.7 | 6 | 1490 | 1250 | 30 | 19 | 88.8 | 889.4 | −0.70 | 7.50 | 4.60 | 0.20 |
AM17 | 42.5 | 6 | 1552 | 1305 | 34 | 16 | 90.1 | 865 | −0.70 | 7.40 | 4.50 | 0.20 |
AM18 | 47 | 6.14 | 1528 | 1250 | 40 | 9.7 | 96.6 | 932.1 | −0.40 | 6.90 | 4.10 | 0.20 |
AM19 | 41.2 | 6.25 | 1680 | 1259 | 43 | 12 | 100.8 | 1,091 | −0.30 | 6.80 | 4.00 | 0.20 |
AM20 | 39 | 5.85 | 587 | 414 | 20.3 | 10.5 | 57.2 | 247.7 | −1.60 | 9.10 | 6.90 | 0.50 |
AM21 | 34.9 | 6.14 | 1759 | 1551 | 57 | 7 | 66.74 | 1161 | −0.40 | 6.80 | 4.00 | 0.10 |
AM21 | 34.9 | 6.14 | 1759 | 1551 | 57 | 7 | 66.74 | 1161 | −0.40 | 6.80 | 4.00 | 0.10 |
AM22 | 39 | 6 | 1,530 | 826.2 | 54 | 8.8 | 62 | 1080 | −0.40 | 6.90 | 3.90 | 0.10 |
AM23 | 32.9 | 6.02 | 1525 | 1388 | 58 | 14 | 67.1 | 1078 | −0.50 | 7.10 | 4.10 | 0.10 |
AM25 | 52.3 | 6.06 | 1441 | 1177 | 33 | 9.9 | 73.84 | 780.8 | −0.50 | 7.10 | 4.40 | 0.20 |
AM26 | 95.8 | 6.88 | 846 | 641.2 | 12.8 | 56 | 26.98 | 485.6 | 0.40 | 6.00 | 4.40 | 2.00 |
AM27 | 15.4 | 4.69 | 192 | 981 | 5.5 | 2.3 | 16.33 | 29.89 | −4.80 | 14.20 | 12.20 | 1.00 |
AM28 | 26.5 | 5.85 | 538 | 410.5 | 14.1 | 10 | 38.34 | 247.7 | −2.00 | 9.90 | 7.70 | 0.30 |
AM29 | 25.9 | 5.8 | 716 | 621.4 | 20 | 9.1 | 40.83 | 378.2 | −1.80 | 9.30 | 6.80 | 0.20 |
AM31 | 20.4 | 5.78 | 520 | 669.2 | 22 | 8.9 | 31.2 | 253.8 | −2.00 | 9.80 | 7.50 | 0.30 |
AM32 | 37.5 | 5.61 | 572 | 842 | 8.5 | 7.1 | 33.4 | 294 | −2.20 | 10.10 | 7.50 | 0.20 |
AM33 | 17.5 | 4.9 | 187 | 681.6 | 11 | 2.4 | 23.1 | 79.3 | −3.80 | 12.40 | 10.00 | 0.50 |
AM34 | 55.4 | 5.91 | 789 | 747 | 15 | 63 | 35.5 | 377 | −1.20 | 8.40 | 6.00 | 0.40 |
AM36 | 95.5 | 7.44 | 994 | 733 | 6.1 | 21 | 96.6 | 416 | 0.60 | 6.20 | 5.30 | 0.50 |
AM37 | 16.1 | 5.28 | 308 | 1353 | 7.8 | 27 | 19.9 | 78.1 | −3.60 | 12.50 | 10.50 | 0.90 |
AM38 | 16 | 4.89 | 356 | 1196 | 6.3 | 33 | 23.4 | 72 | −4.10 | 13.10 | 10.80 | 1.10 |
AM41 | 23.4 | 5.48 | 906 | 1524 | 77 | 92 | 80.94 | 336.7 | −1.60 | 8.80 | 6.00 | 0.80 |
AM42 | 32.8 | 7.58 | 1339 | 801 | 55 | 71 | 177.2 | 483.1 | 0.70 | 6.20 | 5.30 | 0.80 |
AM43 | 45.9 | 6.46 | 1239 | 895 | 57 | 63 | 133.8 | 599.0 | −0.10 | 6.60 | 4.50 | 0.50 |
AM44 | 18.6 | 5.71 | 1167 | 1456 | 35 | 15 | 70.65 | 684.4 | −1.40 | 8.60 | 5.60 | 0.20 |
AM45 | 17.9 | 5.3 | 377 | 979.3 | 16.7 | 2.1 | 26.63 | 170.2 | −2.90 | 11.00 | 8.50 | 0.30 |
AM46 | 15 | 4.87 | 139 | 949.9 | 8.8 | 6.2 | 16.68 | 67.1 | −4.00 | 12.90 | 10.60 | 0.50 |
AM47 | 17.4 | 5.2 | 326 | 747.2 | 5.6 | 13 | 47.2 | 65.9 | −3.80 | 12.90 | 10.90 | 1.50 |
AM48 | 18.1 | 4.66 | 184 | 1010 | 4.1 | 6 | 30.18 | 23.18 | −5.00 | 14.60 | 12.70 | 2.60 |
AM49 | 15.2 | 4.99 | 158 | 519.8 | 4 | 5.7 | 25.92 | 27.45 | −4.60 | 14.20 | 12.60 | 1.90 |
AM50 | 18.6 | 4.61 | 179 | 831.3 | 3.6 | 5.6 | 25.2 | 21.96 | −5.10 | 14.80 | 12.90 | 2.30 |
AM51 | 30 | 5.03 | 295 | 473.2 | 9.5 | 5.6 | 32 | 111 | −3.30 | 11.60 | 9.10 | 0.60 |
AM52 | 34.7 | 5.12 | 459 | 1077 | 11.1 | 6 | 53.3 | 176.9 | −2.90 | 10.90 | 8.20 | 0.60 |
AM53 | 19.4 | 4.8 | 194 | 1,070 | 3.7 | 4.6 | 33.02 | 23.18 | −4.90 | 14.50 | 12.80 | 2.70 |
AM54 | 70.3 | 5.98 | 360 | 386 | 8.9 | 19.5 | 35.14 | 88.45 | −1.80 | 9.50 | 8.10 | 1.00 |
AM55 | 16.5 | 5.09 | 330 | 1367 | 5.9 | 24 | 18.5 | 275.7 | −3.40 | 11.80 | 8.80 | 0.20 |
AM61 | 28.8 | 4.66 | 264 | 1041 | 4.6 | 56 | 23.8 | 29.3 | −4.60 | 13.90 | 11.90 | 3.80 |
AM62 | 36.2 | 4.28 | 182 | 544 | 3.9 | 31 | 20.9 | 28.1 | −4.90 | 14.10 | 11.70 | 2.70 |
AM69 | 18.5 | 4.65 | 326 | 1061 | 6.5 | 6.7 | 60.4 | 18.3 | −4.90 | 14.40 | 12.70 | 6.10 |
AM71 | 67.7 | 5.97 | 4,220 | 85,440 | 500 | 1,814 | 4,009 | 553.9 | 0.50 | 5.90 | 2.40 | 16.60 |
AM75 | 43 | 5.78 | 20,200 | 14,076 | 240 | 797 | 7455 | 596.6 | −0.30 | 6.40 | 3.60 | 23.20 |
AM76 | 32.8 | 6.36 | 20,140 | 7,953 | 140 | 352 | 4012 | 608.8 | −0.10 | 6.60 | 4.40 | 12.10 |
AM78 | 16 | 6.86 | 3980 | 2,523 | 44.5 | 184.5 | 1317 | 84.8 | −1.30 | 9.40 | 8.90 | 29.50 |
AM82 | 39.7 | 6.85 | 10,140 | 6778 | 174 | 228 | 3128 | 963.8 | 0.80 | 5.30 | 3.20 | 5.90 |
AM83 | 53.2 | 6.37 | 43,100 | 20,932 | 683 | 1,460 | 8821 | 712.5 | 1.00 | 4.40 | 2.10 | 23.90 |
AM84 | 38.6 | 6.75 | 13,100 | 6754 | 83 | 460 | 3,419 | 754 | 0.20 | 6.30 | 4.30 | 8.60 |
AM86 | 24.1 | 6.74 | 1234 | 826.7 | 67 | 6.5 | 47.6 | 707.6 | −0.10 | 6.90 | 4.90 | 0.10 |
AM87 | 46.5 | 6.68 | 1244 | 745.9 | 47 | 50 | 95.8 | 577.1 | 0.00 | 6.60 | 4.70 | 0.40 |
AM89 | 20.5 | 5.69 | 10,210 | 5,761 | 91 | 435 | 3,220 | 658.8 | −1.20 | 8.00 | 5.10 | 9.20 |
AM90 | 20.9 | 5.79 | 1334 | 1118 | 16 | 49 | 300.3 | 154.9 | −2.40 | 10.50 | 8.60 | 3.70 |
AM94 | 15.5 | 5.76 | 203 | 220.9 | 9 | 3.5 | 23.1 | 72.4 | −3.00 | 11.80 | 10.30 | 0.60 |
AM95 | 15 | 5.35 | 192 | 322.3 | 9.2 | 4 | 21.6 | 61 | −3.50 | 12.40 | 10.6 | 0.70 |
AM99 | 35.1 | 6.09 | 6570 | 4310 | 111 | 194 | 2,016 | 426.4 | −0.60 | 7.30 | 5.00 | 8.70 |
AM100 | 18 | 6.05 | 9440 | 6,316 | 195 | 95.94 | 3,337 | 405.0 | −0.70 | 7.50 | 5.20 | 14.50 |
Water Source | T/°C | pH | κ/μS·cm−1 | TDS/mg·L−1 | [Ca2+]/mg·L−1 | [SO42−]/mg·L−1 | [Cl−]/mg·L−1 | [HCO3−]/mg·L−1 | LSI | RSI | PSI | LI |
---|---|---|---|---|---|---|---|---|---|---|---|---|
AM56 | 22.5 | 5.27 | 537 | 1292 | 10.8 | 5 | 18.8 | 279.4 | −2.80 | 10.80 | 8.00 | 0.10 |
AM57 | 20.3 | 5.48 | 575 | 795.9 | 12.3 | 3.4 | 17.8 | 347.7 | −2.40 | 10.40 | 7.60 | 0.10 |
AM64 | 31.1 | 6.36 | 2090 | 1395 | 20 | 71 | 446.9 | 361.1 | −1.20 | 8.70 | 6.80 | 2.40 |
AM66 | 17 | 6.15 | 403 | 400.2 | 8.2 | 9.8 | 32.31 | 87.84 | −2.60 | 11.30 | 10.10 | 0.80 |
AM67 | 27.5 | 5.6 | 590 | 728.8 | 20 | 5.7 | 55.38 | 229.4 | −2.20 | 9.90 | 7.50 | 0.40 |
AM68 | 26 | 5.27 | 394 | 949.1 | 12.2 | 13.3 | 51.5 | 117.7 | −3.00 | 11.30 | 9.00 | 0.90 |
AM73 | 58 | 6.1 | 27,000 | 19,299 | 310 | 1120 | 10.50 | 608 | 0.40 | 5.40 | 2.80 | 32.10 |
AM74 | 57 | 6.2 | 28,000 | 19,672 | 317 | 1118 | 10.63 | 617 | 0.20 | 5.80 | 3.80 | 62.20 |
AM80 | 27.5 | 7.82 | 1153 | 564.3 | 25 | 29 | 277.2 | 81.7 | −0.30 | 8.40 | 8.90 | 6.30 |
AM81 | 36.3 | 6.4 | 42,000 | 29,127 | 630 | 1450 | 16,200 | 1226 | 0.90 | 4.70 | 2.00 | 24.20 |
AM101 | 39 | 6.04 | 7440 | 5102 | 183 | 226.6 | 2336 | 402.6 | −0.40 | 6.80 | 4.50 | 10.70 |
3.2. Determination of the Corrosive Action of the Natural Waters Using Electrochemical Measurements
Metal | Water Source AM3 | ||||
---|---|---|---|---|---|
Ecor/mV vs. SCE | jcor/μA·cm−2 | βa/mV | −βc/mV | rcor/mm·year−1 | |
Zn | −1097.30 | 47.12 | 124.49 | 169.76 | 0.12 |
Cu | −107.56 | 5.53 | 68.72 | 142.62 | 1.07 × 10−2 |
Cr–Ni | - | - | - | - | - |
Brass | −118.87 | 5.73 | 54.32 | 112.38 | 1.10 × 10−2 |
Carbon Steel | −733.40 | 53.71 | 99.94 | 278.44 | 0.1 |
Galvanized Steel | −1035.90 | 7.0 | 81.17 | 154.5 | 1.75 × 10−2 |
304 SS | −112.18 | 0.33 | 217.16 | 85.83 | 5.74 × 10−4 |
316L SS | −102.42 | 0.56 | 100.88 | 96.12 | 9.80 × 10−4 |
Water source AM9 | |||||
Zn | −1022.02 | 12.58 | 70.12 | 245.03 | 3.14 × 10−2 |
Cu | −142.64 | 10.32 | 83.2 | 271.62 | 1.99 × 10−2 |
Cr–Ni | −278.99 | 1.03 | 230.56 | 78.05 | 1.85 × 10−3 |
Brass | −182.76 | 8.28 | 56.03 | 115.62 | 1.59 × 10−2 |
Carbon Steel | −777.16 | 34.32 | 62.78 | 335.21 | 6.63 × 10−2 |
Galvanized Steel | −1006.10 | 52.04 | 114.0 | 647.54 | 0.13 |
304 SS | −276.44 | 0.99 | 304.83 | 72.2 | 1.71 × 10−3 |
316L SS | −195.30 | 5.37 × 10−2 | 181.02 | 46.29 | 9.32 × 10−5 |
Water source AM34 | |||||
Zn | −1075.74 | 15.44 | 65.76 | 104.77 | 3.85 × 10−2 |
Cu | −112.05 | 10.66 | 60.71 | 136.54 | 2.06 × 10−2 |
Cr–Ni | - | - | - | - | - |
Brass | - | - | - | - | - |
Carbon Steel | −750.63 | 50.29 | 97.01 | 221.34 | 9.72 × 10−2 |
Galvanized Steel | −1078.73 | 30.32 | 71.36 | 140.93 | 7.57 × 10−2 |
304 SS | −228.79 | 1.11 | 257.16 | 92.09 | 1.92 × 10−3 |
4. Conclusions
- The extension of the stability and scaling indexes commonly employed in the characterization of cooling waters in the industry to the characterization of natural waters from geothermal origin is satisfactory.
- The boiling pools, springs and drained wells present in the Archipelago of the Azores are mostly corrosive for structural metallic materials, as seen from the values obtained for the Langelier Saturation, Ryznar Stability, Puckorius Scaling, and Larson–Skold Indexes.
- According to the Langelier Saturation Index, more than 83% of the waters promote corrosion. By type of water, it has been found that the ratio of samples with corrosive characteristics amounts 87.7% for waters from springs (spr), 60% for waters from boiling pools (bp), and 72.7% of those from drained wells (dw). Yet, the values obtained for the hot springs (bp) must be taken only as indications because the high temperatures of these waters would require a more detailed study of their aggressiveness against those metals most commonly used for storing and piping.
- The preliminary electrochemical characterization of the corrosion rates of various metals of a wide industrial use in three water sources from São Miguel Island shows that the measured corrosion rates are very high for all the metals except 304 and 316 L stainless steels and the Cr–Ni alloy.
- These results provide a basis to initiate a combined electrochemical investigation of the aggressiveness of these natural waters both at higher temperatures as well as using condensed water collected from the boiling pools.
Acknowledgments
Author Contributions
Conflicts of Interest
References
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Vasconcelos, H.C.; Fernández-Pérez, B.M.; González, S.; Souto, R.M.; Santana, J.J. Characterization of the Corrosive Action of Mineral Waters from Thermal Sources: A Case Study at Azores Archipelago, Portugal. Water 2015, 7, 3515-3530. https://doi.org/10.3390/w7073515
Vasconcelos HC, Fernández-Pérez BM, González S, Souto RM, Santana JJ. Characterization of the Corrosive Action of Mineral Waters from Thermal Sources: A Case Study at Azores Archipelago, Portugal. Water. 2015; 7(7):3515-3530. https://doi.org/10.3390/w7073515
Chicago/Turabian StyleVasconcelos, Helena Cristina, Bibiana María Fernández-Pérez, Sergio González, Ricardo Manuel Souto, and Juan José Santana. 2015. "Characterization of the Corrosive Action of Mineral Waters from Thermal Sources: A Case Study at Azores Archipelago, Portugal" Water 7, no. 7: 3515-3530. https://doi.org/10.3390/w7073515