For water to become suitable for human consumption in most water treatment plants this occurs by making use of the chlorination process where the organic matter is destroyed by the action of chlorine. Chlorine is a disinfectant that at low concentrations meets requirements such as not being toxic to humans and inactivating microorganisms. The reaction of chlorine with organic compounds results in chlorination byproducts, many potentially harmful to human health, such as trihalomethanes, haloacetic acids, among others. The present work aimed to collect and analyze samples of treated water from reservoirs from public schools in the city of Maringá, Brazil. Analyses of haloacetic acids (HAA5: monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, bromoacetic acid and dibromoacetic acid), natural organic compounds and free residual chlorine were performed (the latter analysis, in loco). The water collection points were chosen in order to maximize the concentration of haloacetic acids that characterize network distant points from treatment station and also samples near the water treatment plant. With the results, the formation of haloacetic acids between the entrance water of the school and the water of the reservoir of the collection points were compared, where higher values were obtained in the reservoirs. Furthermore, the haloacetic acid levels of water supplied to the population close to the treatment station and distant points of the treatment station were compared, resulting in larger values at the distant points. The value of 0.170 mg/L in haloacetic acid (the maximum value allowed by the legislation is 0.080 mg/L) was obtained at a point distant in the network from the treatment plant. The Consolidation Ordinance n.5/2017, current legislation for treated water in Brazil, was used in relation to the maximum allowable values for free residual chlorine and haloacetic acids.
References
[1]
Postigo, C., Emiliano, P., Barceló, D. and Valero, F. (2018) Chemical Characterization and Relative Toxicity Assessment of Disinfection Byproduct Mixtures in a Large Drinking Water Supply Network. Journal of Hazardous Materials, 359, 166-173. https://doi.org/10.1016/j.jhazmat.2018.07.022
[2]
Andreola, R., Mannigel, A.R., de Souza Bido, G., Teixeira, T.M., Filho, E.S., De Oliveira, J.R., Da Costa, A.R. and Paixão, R.M. (2018). Levels of Trihalomethanes in Stored Water from High and Fundamental Schools: Comparison between Two Temporal Data Sets. Journal of Water Resource and Protection, 10, 577-586. https://doi.org/10.4236/jwarp.2018.106032
[3]
Lopes, V.C. and Libanio, M. (2005) Proposição de um índice de qualidade de estações de tratamento de água (IQETA). Engenharia Sanitaria e Ambiental. Rio de Janeiro, 10, 318-328. http://www.scielo.br
[4]
Paixão, R.M., da Silva, L.H.B. and Andreola, R. (2014) A cloração e a formação de trialometanos. Iniciação Científica Cesumar, Maringá, 16, 191-198. http://periodicos.unicesumar.edu.br
[5]
BRASIL (2018) Portaria MS 2914, de dezembro de 2011. Dispõe de procedimentos de controle e de vigilancia da qualidade da água para consumo humano e seu padrão de potabilidade. http://bvsms.saude.gov.brl
[6]
BRASIL (2018) Portaria de Consolidação MS 05, de dezembro de 2017. Consolidação das normas sobre as ações e os serviços de saúde do Sistema único de Saúde. http://bvsms.saude.gov.brl
[7]
Zarpelon, A. and Rodrigues, E.M. (2002) Os Trihalometanos na água Consumo Humano. Rev. Tec. da Sanepar SANARE, n.17, Janeiro a Junho.
[8]
ABNT (Associação Brasileira de Normas Técnicas) (1987) Norma Brasileira Regulamentadora. NBR 9898. Preservação e técnicas de amostragem de efluentes líquidos e corpos receptores. Rio de Janeiro, 22 p.
[9]
ANA (Agência Nacional das águas) and CETESB (Companhia de Tecnologia de Saneamento Ambiental do Estado de São Paulo) (2011) Guia nacional de coleta e preservação de amostras: água, sedimento, comunidades aquáticas e efluentes líquidos. ANA, Brasília; CETESB, São Paulo, 326 p.
[10]
APHA (American Public Health Association), AWWA (American Water Works Association) and WEF (Water Environment Federation) (1998) Standard Methods for the Examination of Water and Wastewater. 20th Edition, APHA, Washington DC.
[11]
USEPA (US Environment Protection Agency) (2003) EPA n.815B03002. Determination of Haloacetic Acids and Dalapon in Drinking Water by Liquid-Liquid Microextraction, Derivatization and Gas Chromatography with Electron Capture Detection. USA, 56 p. https://www.epa.gov
[12]
Tominaga, M.Y. and MIDIO, A.F. (1999) Exposição humana a trialometanos presentes em água tratada. Revista de Saúde Pública. São Paulo, 33, 413-421. http://www.scielo.br