A eutrofização artificial de cursos d'água urbanos como fenômeno de ancoragem para abordar educação ambiental e sustentabilidade no ensino médio

Abstract

Science Teaching through Investigation seeks to form more critical citizens who are aware of how knowledge in science is constructed. This approach aims to promote students' scientific literacy, based on several structuring axes, among which the Science, Technology, Society and Environment perspective stands out. Considering the reality of the educational establishment in which this project was developed – a state public school in Belo Horizonte, located close to the Arrudas River – we decided to develop and analyze a Didactic Sequence (DS), using the artificial eutrophication of urban watercourses as anchoring phenomenon to address local and global environmental problems with 65 students in their first year of high school. DS consists of the steps: initial diagnosis; contextualization; hypothesis raising; concept of artificial eutrophication; analysis of official data on water potability in urban rivers; drafting a letter to the state environment department; final diagnosis. Data collection was carried out through logbook recording and descriptive analysis, with a qualitative (content analysis proposed by Bardin) and quantitative (student's t-test) approach, of the materials produced by the students. The results show that some previous conceptions, such as the idea that the potability of water can be identified through organoleptic properties, are very consistent among the participants. However, approximately one third of the students, after the application, were able to mention the importance of microbiological analysis and the fecal coliform rate to prove the potability of the water. The concept of artificial eutrophication became part of the repertoire of more than 40% of them. It was also possible to notice an increase in students' ability to relate water pollution to the importance of the population's and public authorities' contribution to promoting actions that minimize their environmental impacts. Therefore, we realized that this DS used the students' reality to address water pollution and artificial eutrophication, as well as relating such phenomena to the need for sustainable development. A good motivation to carry out the proposed activities was perceived, a fact that could be proven by analyzing the results of the motivation to learn questions. It is possible that this DS could be adapted, in whole or in part, in accordance with the instructions provided in this work, for development in other high schools, in the disciplines of Biology and Natural Sciences and their Technologies.