Europe aims to reach climate neutrality and a circular economy by 2050. Current practices to treat industrial wastewater by large are not designed for the water valorisation and reuse and, therefore, are not coherent with the European ambitions. To design the wastewater treatment systems compatible with the requirements of circular economy, CORNERSTONE aims at integrating novel technological and digital developments into the existing industrial wastewater treatment systems for recovery and recycling of freshwater, energy and solutes. The project introduces innovative principles and practices at the component level and rationally integrates the developed components to recover valuables and freshwater from industrial wastewater. To achieve its objective, CORNERSTONE puts together a multidisciplinary 16-partner consortium from 8 European member states, consisting of large enterprises, academia, and research & technology organisations. The project targets steel, pulp and paper and chemical industries as the end users due to their importance in realizing the objectives of P4Planet in transforming European process industries to make them circular and achieve overall climate neutrality at EU level by 2050, while enhancing their global competitiveness. CORNERSTONE builds on the success of former initiatives and projects which have delivered technological, methodological and community assets that CORNERSTONE will convincingly and coherently leverage and advance to achieve its objectives. The project designs also ensures that new developments, together with digital tools can be easily deployed cross-sectorial and deliver long-lasting impacts to a sustainable European industrial water management approach.