100

Given that many voices have argued in favour of combining insights on urban metabolism from different disciplinary angles, there seems to be no lack of general willingness to engage in interdisciplinary research on urban metabolism. Instead, we argue, the central problem lies in the nitty-gritty and mundane practicalities of working across research teams, departments and temporalities. In this paper, we offer a detailed description of an interdisciplinary collaboration that has occurred in practice: a joint effort on the study of potential transition scenarios regarding the metabolism of biowaste in the city-region of Brussels. This inter-project collaboration involved four different research teams from three faculties and two universities, each with a specific set of expertise and interests. Biowaste metabolism and nutrient recirculation is a recurring theme in the literature on urban metabolism. It relates to early studies on urban metabolism and concerns about the depletion of soil fertility and different forms of pollution. The paper describes each research project point of departure in order to allow readers with different disciplinary backgrounds to apprehend the distance that separated the projects before they decided to work together on the urban biowaste metabolism. Furthermore, we present moments of convergence that helped to bring these research processes together. Finally, we offer a critical reflection, suggesting both enabling factors and limits of the inter-project collaboration on biowaste metabolism in Brussels.