On April 9th, 2022, in the village of Santo Pietro, Caltagirone (CT, Sicily), a technical seminar titled “PAUlab_Laboratory of Architectural and Urban Design” was held, curated by Prof. Marco Navarra.  During the event, Prof. Giuseppe Luigi Cirelli delivered a significant presentation titled “Nature-based solutions (NBS) for the treatment and recovery of waters”. The presentation navigated through the potentials and applications of NBS in various contexts, including the sustainable management of water resources and adaptation to climate change in urban and peri-urban areas. Various aspects of phytopurification techniques were explored in-depth, illustrating how phytopurification systems emulate the natural purification processes of wetlands and how they can be classified based on hydraulic operation, such as surface and subsurface flow systems. The discussion was enriched by practical examples and images from various parts of the world, such as France and India, showcasing the application and efficacy of these nature-based solutions in real-world contexts. Moreover, Prof. Cirelli shared details about the ongoing activities in the GIFLUID project, exploring NBS in the cross-border territories of Malta and Sicily, and presented various types of green infrastructures, highlighting the wide range of applicability and the environmental and social benefits that stem from implementing such solutions. Further details and strategies are available in the csei notebooks, accessible online on the CSEI CATANIA website