Frank Oesterholt is a senior researcher and project manager on the Industry, Wastewater and Reuse team. His specialities are process water treatment, water reuse and water loop closure. For example, he worked for a consortium on the ‘critical success factors for water loop closure in industry’. Frank is project manager of the research into the CoRe Water concept, which promotes the transition of existing WWTPs to water and energy factories in the future. He is also the head research scientist of the power-to-protein concept, which aims to produce proteins from raw materials generated in the water cycle (powertoprotein.eu). Frank is moreover a specialist in Legionella prevention, particularly regarding risk analysis and management plans. He has written on the subject, including the Dutch Health and Safety Executive information page on Legionella (AI-32), published by Sdu, which focuses on cooling-water and process-water systems. He is a member of the Nationwide Consultation Platform for Legionella (LOPL). Frank also specialises in water and energy. Over the last few years, he worked on research focused on heat and cold recovery from drinking water (TED), on the role of drinking water utilities in a future hydrogen-based economy and, more recently, he developed a Code of Practice for calculating climate neutrality in the drinking water sector.