This review explores the role of nature-based solutions (NBS), particularly those utilising (micro)organisms, in enabling resource recovery within urban environments under the circular economy framework. Drawing on extensive literature and over 90 European innovation projects from the COST Action Circular City network, it examines NBS applications for treating urban and industrial wastewater, municipal solid waste, and gaseous effluents. The study analyses recoverable products such as nutrients, nanoparticles, and energy, and evaluates technology readiness levels alongside challenges related to source-separation and circularity by design. The review identifies barriers to implementation and emphasises the potential of NBS to advance resilient, self-sustainable cities.
alchemia-nova | institute for innovative phytochemistry & closed loop processes