Phytoremediation as urban regeneration strategy: A framework for sustainable land reclamation in the Milan Metropolitan Area

Urban brownfields and degraded areas pose pressing environmental and social challenges, especially in metropolitan contexts shaped by industrial legacies and land-use transformations. Among the nature-based solutions available, phytoremediation, using plants to mitigate soil contamination, offers a sustainable, low-impact alternative to conventional reclamation techniques. Despite its ecological benefits, phytoremediation remains underused in urban planning due to uncertainties and long treatment times. This study applied a GIS-based multi criteria analysis integrating open source spatial data, soil parameters, and satellite image interpretation to identify suitable areas for phytoremediation within the Milan Metropolitan Area (MMA). A weighted evaluation framework was developed by considering soil characteristics (texture and organic carbon content), vegetation cover, site size, and total available free surface (areas not occupied by built structures) to calculate suitability indices. Results show that out of 720 mapped sites, approximately 40 % displayed good or high suitability for phytoremediation, highlighting important opportunities for sustainable soil regeneration within the urban fabric. Integrating environmental planning and landscape design perspectives, the findings support a broader vision of sustainable urban transformation and demonstrate how soil regeneration can play a critical role in shaping future green infrastructure and ecological networks.