This work presents an innovative educational experience aimed at introducing high school students to real-world laboratory procedures used in the treatment of urban wastewater, focusing on coagulation-flocculation testing. The initiative consisted of hands-on engineering workshops designed to simulate authentic laboratory conditions and enhance student understanding of environmental chemical engineering processes.

During the workshops, students were guided through each stage of a typical coagulation-flocculation experiment. Initially, they were introduced to the basic principles of the process, including the physicochemical mechanisms involved in particle aggregation and separation. Participants then applied these concepts by performing calculations related to the preparation of coagulant solutions and the estimation of dosages.

The experimental part was carried out using a jar-test apparatus, a standard device in water treatment laboratories that allows simultaneous comparison of different treatment conditions. Students tested several types of coagulants commonly used in wastewater treatment, such as aluminum sulfate and ferric chloride, to evaluate their efficiency, cost-effectiveness, and environmental impact. By adjusting the concentration of each reagent and observing the resulting clarification of the water samples, students were able to determine the most effective treatment strategy for a sample of urban wastewater.

This activity provided students with a comprehensive view of the steps involved in designing and optimizing a water treatment process. In addition to acquiring technical skills, they developed competences in critical thinking, data analysis, teamwork, and scientific communication. Beyond the acquisition of scientific knowledge and technical skills, this project played a key role in fostering students’ awareness of the relevance of environmental engineering in society and its potential as a professional field. By engaging in a process that mirrors real-world scientific practice, students could envision the direct application of what they learn in the classroom to pressing societal challenges, such as water pollution and resource sustainability. This alignment between educational content and practical utility not only enhances motivation and learning outcomes but also serves as a catalyst for awakening scientific vocations. Ultimately, the initiative aims to inspire students to pursue further studies and careers in science, technology, engineering, and mathematics (STEM), contributing to the development of a new generation of professionals committed to environmental stewardship and innovation.

The success of this educational initiative highlights the value of experiential learning in science and engineering education. By connecting theoretical concepts with practical applications, students were able to engage more deeply with environmental issues and consider future academic or professional pathways in this field. This experience demonstrates the effectiveness of integrating laboratory-based, real-world problem solving into pre-university curricula to foster interest in environmental technologies and sustainable development.

Keywords: Experiential Learning, STEM Education, Environmental Engineering Education, High School Science Engagement.