Caracterização radioquímica, química e mineralógica do lodo da estação de tratamento de água de Ponta Grossa - PR

Abstract

Water treatment systems have the important purpose of providing drinking water to the population, and with the increase of the demand and consequently, the water production is also expected to increase, in order to guarantee water with quality to everyone. The raw water is treated through physical and chemical processes, with generation of sludge. The sludge is mainly the result of chemical products used in the water treatment and of the raw water quality, and for technical and environmental reasons it must be treated before being disposed in the environment. The Water and Sanitation Company of Parana (SANEPAR) treats the water to supply the city of Ponta Grossa, Paraná, through two Water Treatment Plants (WTP): Pitangui WTP with conventional treatment, and Actiflo® WTP which uses micro sand to improve the particles removal in the treatment units. The raw water of the WTPs is from the Pitangui river and the Alagados dam, which is formed by the Pitangui and Jotuba rivers. These two sources of water have their heterogeneous traces defined by the Serra do Carambeí Granite, which in many studies has already proven their radianomal features with elements such as uranium (238U), thorium (232Th) and potassium (40K). In this work was done the radiochemical, chemical and mineralogical characterization of sludge samples from the WTPs, in order to identify the presence of those chemical elements in the sludge and to suggest an appropriate final destination to it. The mean concentrations obtained were: 7.5 ppm of 238U, 13.53 ppm of 232Th and 0,183% of 40K. With the confirmation of these elements into the sludge, we concluded that they were removed in the water treatment and it is necessary the treatment and an appropriated disposal of this residue.