Education for sustainable development through waste valorisation research projects: training sustainability competencies in agro-industrial engineering students during the COVID-19 pandemic

Purpose This paper aims to examine how education for sustainable development (ESD) can be effectively implemented within higher education institutions through authentic waste valorisation research projects, even under the challenging circumstances of the COVID-19 pandemic. This study demonstrates how final-degree projects (FDPs) focused on circular economy principles can develop key sustainability competencies in agro-industrial engineering students while contributing to Sustainable Development Goals (SDGs) 4 and 12. We analyse how integrating problem-based learning, project-based learning, learning-by-doing and research-based learning approaches creates synergistic effects for competency development. Design/methodology/approach A multiple-case study methodology was used to analyse three FDPs focused on agro-industrial waste valorisation (coffee residues, goat milk whey and cocoa pod husks) conducted between March 2020 and March 2022 at a public university in Ecuador. Quantitative data from 229 graduates across seven engineering programmes were integrated with qualitative analyses of pedagogical strategies and competency development indicators. Findings Despite severe pandemic restrictions, including laboratory closures and mandatory confinement, 229 students completed their research theses during the study period. The cohort achieved a 13.1% publication rate (30 publications from 229 theses), with 46% of journal articles published in Q1- and Q2-ranked journals. The three detailed case studies resulted in publications in high-impact journals, demonstrating novel approaches to waste valorisation. Students developed measurable sustainability competencies, including systems thinking, anticipatory competence, normative competence, strategic competence and interpersonal competence. Research limitations/implications This study is limited to a single institution in Ecuador and focuses specifically on agro-industrial engineering programmes within the Faculty of Agricultural and Environmental Sciences Engineering. The pandemic context, while providing unique research opportunities, also constrained specific methodological approaches. However, the methodology demonstrates transferability to other disciplines and institutional contexts where waste valorisation and circular economy concepts are relevant to local sustainability challenges. Because the case studies were selected for success, conclusions about competency development should be interpreted as demonstrating what the model can achieve under favourable conditions rather than as representative of all FDP outcomes. Practical implications The findings provide a replicable model for integrating ESD into higher education curricula through authentic research projects addressing real sustainability challenges. Social implications By training future researchers and pre-professionals in waste valorisation and circular economy principles, this educational approach helps build local capacity for sustainable development in developing countries. Originality/value This paper provides novel empirical evidence on how ESD can be effectively implemented through waste-valorisation research projects in Latin American universities. The study’s principal originality lies in its artefact-based approach to competency evidencing: rather than relying solely on self-report instruments, competency claims are triangulated with observable indicators drawn from thesis documents, logbooks and published articles, thereby providing a replicable assessment methodology for ESD in research-intensive programmes.