Avaliação da formação de subprodutos da cloração em água para consumo humano

• Ano de defesa: 2010
• Autor(a) principal: Janaina Abreu Alvarenga
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Meio Ambiente e Recursos Hídricos; Saneamento; Água Qualidade; Engenharia sanitária
• Link de acesso: http://hdl.handle.net/1843/ENGD-88PRAN

This study aimed to evaluate the concentration of chlorination by-products in finished drinking water, in three water system distribution that have different water sources and treatment technologies, refered in this research as ETA A (complete water treatment), ETA B (direct descending filtration/ flotation) and ETA C (direct descending filtration). Treated water samples were collected monthly from March 2009 to February 2010. The raw water characterization was carried through the physical and chemical parameters pH, temperature, apparent color, turbidity, total alkalinity and dissolved organic carbon. In treated water, the analyzed parameters were: pH, temperature, free chlorine and chlorination by-products (trihalomethanes, haloacetic acids, halopicrin, haloacetonitrilas, haloketone and chloral hydrate), quantified by gas chromatography with electron capture detector. The results showed that, through the Spearman correlation matrix, the monitored parameters (temperature, pH and residual chlorine), often did not show correlation coefficients statistically significant with by-products formation. Among trihalomethanes, chloroform showed the highest concentration, as in the output of ETAs A, B and C, as in their distribution system. In these sampling points, the total haloacetic acids concentrations often exceeded total trihalomethanes concentrations. The latter by-product was found in all analysis conducted in the waters of ETAs A and B, at concentrations below the limit of the current Brazilian drinking water guideline, at 0,1 mg.L-1, and haloacetic acids concentrations lower than the standard regulated in the United States, limited to 60 g.L-1. At the ETA C, 37% e 58% of total samples exceeded the limits for trihalomethanes and haloacetic acids mentioned above, with these compounds presenting values of 317 and 334 g.L-1, respectively, which may result from the high density of phytoplankton in the water source. In ETA C was found the occurrence of chloral hydrate, haloacetonitrilas and haloketones in 87, 96 e 79%, respectively. The results indicates that should be considered the addition of new chlorination by-products in brazilian drinking water guideline, especially haloacetic acids.