Advanced oxidation has proven to be an efficient process to increase micropollutant removal compared to conventional ozonation and to lower considerably the load to subsequent activated carbon treatment. Laboratory tests to determine the most important reaction rate constants involved in conventional and advanced oxidation and the OH radical/ozone ratio in the specific water to be treated can provide the basic parameters to simulate direct ozone and OH radical reactions. The combination of tracer based hydraulic reactor and chemical reaction modelling made it possible to simulate full-scale reactor performance. Model extrapolations used to optimise the peroxide dosing point for maximum micropollutant removal showed that disinfection for Cryptosporidium may severely be impaired.