Caracterização da qualidade da água de uma microbacia urbana e uso de biofilme como ferramenta para biomonitorar metais potencialmente tóxicos

• Autor(a) principal: Almeida, Karine Paz de
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFMT
• Texto Completo: http://ri.ufmt.br/handle/1/5310
• topic: Biofilme; Metais potencialmente tóxicos; Qualidade da água e bactérias heterotróficas; CNPQ::ENGENHARIAS::ENGENHARIA SANITARIA::RECURSOS HIDRICOS; Biofilm; Potentially toxic metals; Quality of water and heterotrophic bacteria

The water quality of Córrego São Gonçalo is compromised due to the continuous disposal of urban solid waste. Practically throughout the studied area is about direct influence of the process of urbanization, with residences and ventures around the creek. This study aimed to explore the use of a new biological tool that can act as an indicator of early warning to the monitoring of potentially toxic metals in the aquatic environment. Thus, microbial biofilms have been shown to be efficient because they respond rapidly to changes in environmental parameters. Biofilms are a community of microorganisms that are adhered to a submerged substrate surrounded by an exopolysaccharide matrix (EPS) composed of extracellular polymeric substances. This matrix confers greater resistance to biofilms ix compared to planktonic cells. The biofilms were cultivated in artificial substratum, for a period of 9 days, in two sample points that comprise the source and mouth of the São Gonçalo creek, Cuiabá-MT. Seven campaigns were carried out (November / 2014 to May / 2015). The parameters analyzed were the metals Al, Fe, Mg and Mn in water and biofilm, the microbial community, by counting UFC in both substrates, and a physical and chemical properties monitoring of the microbasin was also performed. The results demonstrate that the water quality of the São Gonçalo stream is compromised, and its classification should be rethought, since many variables were not included in the CONAMA 357/05 legislation. The biofilms showed to be efficient for biomonitoring metals, considering the average of the values found for Al, Fe, Mg and Mn, it was observed that the highest concentration of the metals studied occurred in the biofilm, which may be related to the exposure time of the Substrate in the water body and the accumulation in the exopolysaccharide matrix (EPS). The results obtained in this study showed that there was no correlation between the potentially toxic metals and the concentration of planktonic cells and biofilms, except for the water Mn that correlated negatively with the biofilm microbial community (-0.52). However the study confirms that biofilms have great potential to be used as a biological indicator, since they were efficient in the detection of metals. It is recommended the effective and continuous monitoring of the water quality of the stream, to subsidize the transient classification of the same.