Hydrochemical and Radiometric Study of Groundwaters from Serra Negra Spa, São Paulo State, Brazil

Hydrochemical and Radiometric Study of Groundwaters from Serra Negra Spa, São Paulo State, Brazil

Pietro D. Avona Daniel M. Bonotto

Departamento de Geologia, Instituto de Geociências e Ciências Exatas – UNESP, Rio Claro, Brazil

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© 2022 IIETA. This article is published by IIETA and is licensed under the CC BY 4.0 license (http://creativecommons.org/licenses/by/4.0/).



This paper presents a novel hydrochemical and radiometric data of groundwater sampled from Serra Negra spa town, São Paulo State, Brazil. Every year, many visitors travel to the municipality, thus, recurrent analyses are recommended and necessary, as the local water is heavily consumed. However, gaps exist in this regard, especially for the groundwater selected for sampling in this paper, since there is no analytical data on its chemical composition. The results obtained were compared with the drinking water standards in relation to the analyzed parameters. The radioactivity of all analyzed samples was below the values  established by the World Health Organization of 0.5 and 1 Bq. L−1 for gross alpha and beta activities, respectively. In general, the hydrochemical parameters analyzed did not exceed the reference limits established by Brazilian and international legislation, with the exception of pH for one water sample and nitrate for another. The use of Pearson’s correlation coefficient reinforced the pro- portionality between electrical conductivity and dissolved salts. In the chemical aspect, the dominant anion in the waters was bicarbonate, agreeing with the observed pH, while the predominant cation was sodium, possibly suggesting a slightly more evolved hydrogeochemical context. Although the Brazilian legislation does not mention a reference value for the ingestion of silicon in water, in this paper some comments were made about its presence in the analyzed groundwaters.


hydrochemistry, potability, radioactivity, Serra Negra spa


[1] CETESB, https://cetesb.sp.gov.br/aguas-subterraneas/

[2] Gleeson, T., Befus, K.M., Jasechko, S., Luijendijk, E. & Cardenas, M.B., The globalvolume and distribution of modern groundwater. Nature Geoscience, 9(2), pp. 161–167, 2016.

[3] World Health Organization (WHO), Guidelines for Drinking-water Quality, fourth edition,vol. 1, WHO Press: Geneva, p. 541, 2011.

[4] Hasui, Y. & Oliveira, M.A.F., Província Mantiqueira – setor central. In: Almeida F.F.M.& Hasui Y., eds., O Pré-Cambriano do Brasil, 1 ed., Edgard Blücher: São Paulo, pp.308–344, 1984.

[5] Campos Neto, M.C., A porção occidental da faixa Alto do Rio Grande: ensaio deevolução tectônica. PhD theses. University of São Paulo: São Paulo (SP), 1991.

[6] Campos Neto, M.C., Perrotta, M.M., Peloggia, A.U.G. & Figueiredo, M.C.H., A porçãooccidental da faixa Alto do Rio Grande SP/MG. Congresso Brasileiro de Geologia,XXXVI Anais, SBG: Natal, pp. 2615–2630, 1990.

[7] Report Qualidade das águas subterrâneas no estado de São Paulo 2016–2018; CETESB– Companhia Ambiental do estado de São Paulo, Online, https://cetesb.sp.gov.br/aguassubterraneas/publicacoes-e-relatorios/. Accessed on: 06 Jan. 2022.

[8] Mente, A., Mapa Hidrológico do Brasil. In: Feitosa, F.A.C., Manoel Filho, J., Feitosa,E.C. & Demetrio, J.G., eds., Hidrogeologia – conceitos e aplicações, CPRM-LABHID:Rio de Janeiro, pp. 31–48, 2008.

[9] Del Rey, A.C., Estudo hidrogeotérmico da região de Águas de Lindóia, Amparo eSocorro – nordeste do Estado de São Paulo. Masters’ dissertation. University of SãoPaulo: São Paulo (SP), p. 124, 1989.

[10] HACH, Water Analysis Handbook, 2 ed., Hach Co.: Loveland, p. 831, 1992.

[11] Bonotto, D.M., Bueno, T.O., Tessari, B.W. & Silva, A., The natural radioactivity inwater by gross alpha and beta measurements. Radiation Measurements, 44(1), pp.92–101, 2009.

[12] Brazilian Ministry of Health. Ordinance No. 2914 of 12 Dez. 2011. Diário Oficial daRepública Federativa do Brasil, Poder Executivo, Seção 1, Ministério da Saúde: Brasília,pp. 39–46, 2011.

[13] Bresler, E., McNeal, B.L. & Carter, D.L., Saline and Sodic Soils: Advanced Series.Agricultural Sciences, vol. 10, p. 236, 1982.

[14] Chang, C., Sommerfeldt, T.G., Carefoot, J.M. & Schaalje, G.B., Relationships of electricalconductivity with total dissolved salts and cation concentration of sulfate-dominantsoil extracts. Canadian Journal of Soil Science, 63, pp. 79–86, 1983.

[15] Sonmez, J.S., Buyuktas, D., Okturen, F. & Citak, S., Assessment of different soil towater rations (1:1, 1:2:5, 1:5) in soil salinity studies. Geoderma, 144, pp. 361–369,2008.

[16] Peinado-Guevara, H., et al., Relationship between chloride concentration and electricalconductivity in groundwater and its estimation from vertical electrical soundings(VESs). Ciencia e investigación agrarian, 39(1), pp. 229–239, 2012.

[17] Kargas, G., Londra, P. & Sgoubopoulou, A., Comparison of soil EC values from methodsbased on 1:1 and 1:5 soil to water rations and ECe from saturated paste extractbasedmethod. Water, 12, p. 1010, 2020.

[18] Ismaylov, A.I., Mamedov, A.I., Fujimaki, H., Tsunekawa, A. & Levy, G.J., Soil salinitytype effects on the relationship between the electrical condutivity and salt content for1:5 Soil-to-water extract. Sustainability, 13(6), p. 3395, 2021.

[19] Slavich, P.G. & Petterson, G.H., Estimating the electrical conductivity of saturatedpaste extracts from 1:5 soil:water suspensions and texture. Australian Journal of SoilResearch, 31, pp. 73–81, 1993.

[20] Kargas, G., et al., Soil Salinity Assessment Using Saturated Paste and Mass Soil: Water1:1 and 1:5 Ratios Extracts. Water, 10, p. 1589, 2018.

[21] Hassannia, M., Nazari, B., Kaviani, A. & Sotoodehnia, A., Evaluation and analysis ofdifferent regression models for estimation of ECe from EC 1:5 – with a case study fromBuin-Zahra, Iran. Irrigation and Drainage, 69, pp. 1192–1203, 2020.

[22] Lazzerini, F.T. & Bonotto, D.M., O silício em águas subterrâneas do Brasil. Ciência eNatura, 36(2), pp. 159–168, 2014.

[23] Fagundo, J.R., Cima, A. & González, P., Revision Bibliografica sobre Classificaciónde las Aguas Minerales y Mineromedicinales. Centro Nacional de Termalismo “VíctorSantamarina”: La Habana, p. 27, 2001.