The COIL (Collaborative Online International Learning) methodology is an educational approach that promotes collaborative and cross-cultural learning through digital technologies. It connects students and faculty from different institutions and countries to work together on projects, enhancing intercultural competence and global skills. COIL focuses on academic exchange and building relationships and mutual understanding through shared learning experiences.

In this context, a presentation on industrial wastewater treatment was adapted to the COIL methodology. This activity was conducted in collaboration between the University of Castilla-La Mancha (UCLM) and the Mexican Center for Research and Technological Development in Electrochemistry (CIDETEQ), involving 19 students (8 from UCLM and 11 from CIDETEQ). The activity was structured in four main phases.

Initially, a theoretical presentation was held to explain the activity dynamics, which involved creating a joint project on industrial wastewater treatment technologies in mixed teams of students from both institutions. Presentations with general information on these technologies were provided, and topics were assigned based on the experience of CIDETEQ students, who were at the master's and doctoral levels. Despite maturity level differences between the students, specific issues were resolved through tutoring, and the activity was successfully completed. Additionally, a PADLET (online collaborative tool) was created to assist students, featuring icebreaker activities, a discussion platform, and a survey to evaluate the activity.

Following the launch, students worked together on developing their presentations, preferring to use WhatsApp and virtual meetings via Teams/Zoom over the provided PADLET for coordination and information sharing. Finally, each group presented their work in a virtual session on Teams, with each presentation lasting 15 minutes and covering the assigned topic.

The work was evaluated by the course professors, with the presentations forming part of the final grade for the course "Technology for Water Treatment," as indicated in the academic guide. Students were also asked to complete a form to provide feedback on the activity. Overall, the satisfaction level was high, although it was noted that the initial presentations were too dense and the use of PADLET was minimal. Nevertheless, 75% of the students rated the activity with a score of 5 on a scale of 1 to 5, indicating a high level of acceptance and satisfaction.

This experience demonstrated the effectiveness of the COIL methodology in fostering international collaboration and joint learning, overcoming cultural challenges through digital technology use.

Keywords: COIL methodology, cross-cultural learning, digital technology.