Análise físico-química e microbiológica da qualidade da água de um córrego de Cocal-PI, Brasil: estratégias para o ensino de Química Ambiental

Abstract

This study analyzed the water quality of a stream located in the Santa Luzia neighborhood, in the municipality of Cocal-PI, which is continuously used by the local population. The objective of this research was to assess the impacts of anthropogenic pollution and use the results obtained as a pedagogical resource for teaching Environmental Chemistry to third-year high school students. To this end, samples were collected at three different points along the stream and subjected to physicochemical and microbiological characterization. The analyses performed included Chemical Oxygen Demand (COD), Dissolved Oxygen (DO), Ammoniacal Nitrogen (N-NH₃), and total and fecal coliforms. The results indicated high levels of contamination, especially at points closest to residential areas and the adjacent avenue, with values reaching 538.61 mg/L (COD) and 816.4 MPN/mL (fecal coliforms). These findings point to environmental contamination caused by domestic sewage discharge and accumulated waste, resulting in ecological imbalance and a threat to public health. Aiming to promote environmental awareness and the preservation of water resources, the experimental results were integrated into the problematization method and applied as an active teaching and learning methodology. This approach combined experimental data with pedagogical tools for investigative analysis, aiming to foster students' critical thinking. The intervention included lectures, experimentation with colorimetric tests, and investigative discussions. The pedagogical approach increased students' correct responses on conceptual questions and stimulated greater interest in the topic. The results demonstrated that scientific education, when combined with active methodologies, enhances and fosters environmental awareness, encouraging students to take a more active and conscious role in preserving water resources