One of the main objective of the ECHIBIOTEB program (Innovating tools for sampling, chemical and biological analyses for the diagnostic of wastewater advanced treatments and sludge treatments, 2011-2014, financed by the French National Research Agency, coordinated by Irstea) is to study some advanced processes such as ozonation (O3) or Granular Activated Carbon (GAC) as example used to treat wastewaters in tertiary stage of wastewater treatment plants (WWTP). The challenges when studying such processes is first to be able to measure organic micropollutants at very low concentrations (sub ng/L level) and second to link the occurrence of contaminants to adverse biological effects. To achieve these goals, 2 strategies were combined: i) targeted chemical analyses on passive sampler (PS) extracts vs. water grab samples, and ii) biological analyses on the same PS extracts and water grab samples. Targeted chemical analyses were performed on POCIS (Polar Organic Chemical Integrative Sampler) extracts for 119 hydrophilic compounds belonging to pharmaceutical, hormone, pesticide and alkylphenol classes and on SPMD (Semi-Permeable Membrane Device) extracts for 46 lipophilic compounds belonging to chlorine pesticides, PAH (Polycyclic Aromatic Hydrocarbon), PCB (PolyChloroBiphenyl), PBDE (PolyBrominated DiphenylEthers) classes. PS extracts were also tested with in vitro bioassays using cell lines with different reporter genes or in order to evaluate oestrogenic and androgenic activities, HAP-like and dioxin-like disruptions and geno- and cytotoxicity. Two one-month-long sampling campaigns were carried out in a same WWTP (Normandie, France) using activated sludge and sand filter as secondary treatment. In the first one, conducted from September 20th to October 18th 2011, ozonation followed by GAC were studied as tertiary treatment. In the second one, from March 13th to April 10th 2012, we focused on ozonation process only. In both campaigns, POCIS were exposed in water during 14 days and SPMD during 28 days. In order to be able to compare these 2 campaigns and the molecule concentrations upstream and downstream the tertiary treatment, POCIS and SPMD were always immersed in an aquarium in the same controlled experimental conditions of flow (280 mL/min), temperature (20° C) and light. To insure quality of data, POCIS and SPMD were exposed in triplicate and field blanks were realized (i.e. PS exposed to the ambient air). In parallel, 2h composite water samples were collected at D0, D14 and D28. The average sampling time of 2h is reliable considering the water residence time in the secondary treatment. As examples of results concerning the use of POCIS to characterize the O3 + GAC process: By comparing the cumulated concentrations in POCIS, the O3 + GAC process was shown efficient to eliminate some organic micropollutants. Indeed, -blockers and more generally pharmaceuticals were very well removed with a concentration in the effluent a thousand times smaller than in the influent. The conclusions were the same with grab sampling. Moreover, the contamination profiles (or fingerprint) were compared between PS and grab sampling. As example, in case of -blockers they are equivalent. We have also compared the time weighted average concentration obtained with POCIS, with water concentrations from grab sampling. POCIS sampling also allowed to decrease limits of detection in tertiary effluent for some molecules. Indeed, 7 compounds were detected in POCIS extracts and not in grab water samples. As example atenolol, sotalol, propranolol, metoprolol, nordiazepam, amitryptilline and alprazolam were detected in POCIS extracts downstream the tertiary treatment and clenbuterol, gemfibrozil, imipramine and doxepine were detected in POCIS extracts upstream the process. As a consequence, POCIS appeared as an interesting tool to characterize tertiary stages of WWTPs with analysis of organic micropollutants at very low concentrations, near the ng/L range. From the biological point of view, oestrogenic, anti-androgenic as well as HAP-like and dioxin-like disruptions were observed in POCIS exposed before the O3 + GAC process. No more biological activity was detected in these POCIS exposed after the process. These biological results matched with the decrease of contaminant concentrations up and downstream the process. Both chemical and biological analyses were in accordance and revealed a good efficiency of the O3 + GAC advance treatment process.