Determination of metals in public water supply: a case study, municipality of Ouro Preto/MG

Abstract

Over the past four decades the concern with the quality of drinking water has been gaining attention in Brazil, creating and improving legal frameworks relevant to the theme. The city of Ouro Preto, Minas Gerais, Brazil, located in the Iron Quadrangle, which due to its geological characteristics allow the occurrence of certain metals in their water sources. In addition, human activities such as mining, agriculture and domestic and industrial activities can change the water characteristics. The water service of the city account with structures of conventional and simplified treatments, in different localities. Faced with the possibility of occurrence of metals and semimetals in water intended for municipal public supply above the maximum permitted limits stablished by the Brazilian law, this study attempts to make the identification and quantification of metals by total reflection X-ray fluorescence (TXRF) in LCMEM-UFOP. Regarding the twenty samples of raw water, three presented results above the maximum allowed for copper, six for zinc and manganese, and nine for iron. Of the twenty treated water samples, two from systems with simplified treatment presented results above the maximum allowed value, one for iron and one for manganese.