Avaliação de cargas poluidoras e contaminantes emergentes na bacia hidrográfica Vacacaí - Vacacaí Mirim

• Autor(a) principal: Pivetta, Glaucia Ghesti
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Manancial - Repositório Digital da UFSM
• Texto Completo: http://repositorio.ufsm.br/handle/1/12974
• topic: Concentração média do evento; Poluição difusa; Análises estatísticas multivariadas; Contaminantes emergentes; Event mean concentration; Diffuse pollution; Multivariate statistical analyzes; Emergent contaminants; CNPQ::ENGENHARIAS::ENGENHARIA CIVIL

The point and nonpoint source pollution released in rivers are the main responsible for the deterioration of the surface water quality. This study aimed to evaluate the water quality of the Vacacai – Vacacai Mirim watershed, in sub-basins located in the city of Santa Maria – RS. In the Vacacai Mirim River, the quality of the water and surface runoff were evaluated through the monitoring of five precipitation events in Joao Goulart sub-basin. The surface runoff negatively influenced the water quality of this water body. The EMC for the analysed parameters, as well as for the transported pollutants masses varied considerably among events. The average EMC for the BOD variable (51.3 mg∙L-1) stands out. The limit established for this variable for class 2 of CONAMA Resolution 357/2005 is only 5 mg∙L-1. Furthermore, the variability of the nonpoint source pollution in Vacacai Mirim River was evaluated in five sub-basins: João Goulart, Rancho do Amaral, Alto da Colina, Menino Deus II, and Menino Deus IV through cluster and principal components analysis using data from current and previous monitoring performed in this watershed. The five sub-basins were grouped according to the water quality and predominant land use and occupation. The BOD variable was essential in the water quality characterization of all sub-basins, and for the majority of them the total coliforms, E. coli, total solids, nitrogen and phosphorus variables were also essentials. In the Vacacai and Vacacai Mirim Rivers the presence of pharmaceutical and hormonal residues was studied in two urban sub-basins with large percentage of impermeable area. In Cancela-Tamandai sub-basin, the hormone etisterone and ibuprofen and paracetamol drugs were detected. The equivalent of 30 tablets of ibuprofen and 15 of paracetamol were released in this water body, on average per day. In the João Goulart sub-basin only the drugs ibuprofen and paracetamol were detected, hence the equivalent daily average load released in this water body is 52 tablets of ibuprofen and 14.5 of paracetamol. The hormones 17β-estradiol, estriol, estrone and megestrol acetate were not detected in the studied watersheds. Therefore, there is the necessity of investments to ensure the improvement of the sewage networks and treatment of domestic effluents, as well as the solid waste collection services. Together these sources contribute to the poor water quality confirmed in this study.