AbstractThe major part of the regulated priority substances and family of compounds defined in the European Water Framework Directive and some other organic micropollutants were tracked in a municipal biotreated secondary effluent. Micropollutants detected in the effluent were subjected to different ozone doses related to different oxidation extents. Ozone confirmed its efficiency in terms of micropollutant reduction when applied to a municipal biotreated effluent. Accordingly, it achieved reductions exceeding 70% for 91% of the pollutants detected at high ozone dose. Organic matter transformation was also investigated by both controlling evolution of surrogates - including chemical oxygen demand, dissolved organic carbon, UV