Danny Harmsen has worked at KWR for more than 25 years. Since 2003, Danny has worked as a researcher on the Water Treatment team. As a researcher, Danny mainly worked on membrane filtration (RO and FO) and advanced oxidation, in which he was involved in projects both in the Netherlands and abroad. Danny was directly involved in the development of the AiRO concept (reversing pollution of membranes by means of air-water flushing) and the OMBR concept (a system to purify wastewater with forward osmosis membranes). Over the past years, Danny worked on all research projects on UV oxidation. He was involved in research into the development of a new type of UV lamp and a model which can help to predict the destruction of organic micropollutants with a UV/H2O2 reactor. Also Danny was involved in research on surface water treatment using Reverse Osmosis with minimal pre-treatment and research about using natural viruses for verification of the disinfection capacity of membrane filtration processes.