This study investigates the sustainable management and utilization of water resources in the fruit processing industry, focusing on a case study from the EU-funded ULTIMATE project. Conducted in a juice factory in Nafplio, Greece, the primary objective is to explore the recovery of polyphenols from water by-product streams generated during orange juice production. The research aims to evaluate the effectiveness of a mobile wastewater treatment unit in selectively adsorbing polyphenols onto a polymeric resin. The following three extraction methods are compared: conventional solvent extraction, subcritical water extraction (SWE), and supercritical CO