Brent Villanueva defends a doctoral thesis on artificial intelligence and circularity in the WEFE Nexus

Supervised by Professor Jordi Morató Farreras at the UNESCO Chair on Sustainability of the UPC, the research proposes an adaptive framework combining artificial intelligence, digital twins, and participatory processes to assess circularity in socio-ecological and technical systems.

On July 17, Brent Villanueva Escobedo defended his doctoral thesis, Design and Application of an AI-Enabled Adaptive Framework for Assessing Circularity in Socio-Ecological and Technical Systems (SETs) within the WEFE Nexus, at the Universitat Politècnica de Catalunya, earning the highest possible distinction, cum laude. Registered in the Doctoral Program in Sustainability, the thesis was supervised by Professor Jordi Morató Farreras and carried out at the UNESCO Chair on Sustainability of the UPC, in Terrassa.The examination committee was composed of Dr Xavier Alvarez (UPC), Dr Carlos Arias (Aarhus University, Denmark), and Dr Nicola Tollin (University of Southern Denmark, SDU).

The research starts from a clear diagnosis: sectoral and indicator-based approaches are insufficient to capture the complexity of circular economy transitions, since they frequently overlook systemic trade-offs, emergent behaviors, and context-specific constraints. In response, the thesis develops, applies, and validates integrated, participatory, and adaptive assessment frameworks grounded in systems thinking and in the Water–Energy–Food–Ecosystems (WEFE) Nexus.

Presented as a compendium of three scientific articles, the work combines a multi-criteria assessment of sustainability and circularity in public water utilities operating in Mediterranean contexts, an evaluation of circular bioeconomy solutions — specifically biochar and agroforestry — and the consolidation of a transferable methodological framework for participatory, AI-enabled circularity assessment. A central component is the AI-enabled WEFE Nexus assessment tool, co-developed by the UPC INLAB and the UNESCO Chair on Sustainability, which integrates a graphical digital twin able to simulate the behavior of coupled WEFE systems and to explore synergies, trade-offs, and future scenarios.

The applied dimension of the thesis draws on a sequence of projects coordinated by or involving the Chair, including the European projects LIFE REAGRITECH and LIFE ECORKWASTE and, above all, the SureNexus project (PRIMA Program, 2022–2025), a Mediterranean initiative bringing together fifteen institutions from seven countries, in which more than seventy nature-based and bioeconomy-based solutions were assessed.

The main conclusion is that circularity is not a fixed or universally optimizable target, but an emergent, context-dependent system property arising from the interaction between environmental processes, infrastructures, institutions, and stakeholder values. The research also shows that artificial intelligence delivers the greatest value when used as an enabling technology for transparency and learning rather than as a black-box optimization mechanism. This line of work will continue through the SIRENA project, funded by the PRIMA Program and coordinated by the National Technical University of Athens.