Proceedings of the 13 th International Conference on Environmental Science and Technology Athens, Greece, 5-7 September 2013 CEST2013_0672 REMOVAL OF EMERGING POLLUTANTS THROUGH WASTEWATER DISINFECTION C. NOUTSOPOULOS 1 , D. MAMAIS 1 , N. THOMAIDIS 2 , E. KOUMAKI 1 , M. NIKA 2 , A. BLETSOU 2 AND A. STASINAKIS 3 1 National Technical University of Athens, Faculty of Civil Engineering Department of Water Resources and Environmental Engineering 5, Iroon Polytechniou, Zografou, Athens 15780, Greece Corresponding author email: cnoutso@central.ntua.gr 2 National and Kapodistrian University of Athens, Department of Chemistry, Laboratory Analytical Chemistry 3 University of The Aegean, Department of the Environment, Water and Air Quality Laboratory EXTENDED ABSTRACT Emerging contaminants is a rather diverse and heterogeneous group of chemicals consisting of pharmaceuticals and personal care products, steroids and hormones, drugs, fragnances, surfactants, flame retardants, perfluorinated compounds, complexing agents, etc. Among these, endocrine disrupting chemicals (EDCs), pharmaceuticals (Phs) and benzotriazoles (BTs) are compounds which present significant scientific interest due to their toxicological and chemical characteristics and their persistent detection in the aquatic environment. Wastewater treatment plants are a well known source and one of the most significant pathways for the transfer of such chemicals to the environment. It is well evidenced that most of these chemicals are only partially removed through biological treatment and therefore being detected in secondary effluents. Disinfection is most often the last stage of treatment before wastewater being disposed to the aquatic environment. The primary goal of disinfection is to reduce the pathogenic content of wastewater and its effectiveness on the removal of such chemicals is not well studied. The objectives of this study were to assess the effectiveness of chlorination and UV disinfection to remove selected EDCs, Phs and BTs from secondary treated wastewater and to further investigate the role of crucial operating parameters such as chlorination contact time and UV dose, wastewater pH and total suspended solids content on process performance. Several chlorination batch tests have been performed with secondary treated wastewater samples, which were spiked with the target compounds and chlorine. A collimated UV source consisting of one low pressure lamp, was employed to assess dose response curves for each sample tested. UV dose (Ct) was calculated as the product of the UV intensity and the contact time. For the determination of the target compounds, wastewater samples before and after disinfection were analyzed. According to the results chlorination leads to an appreciable removal of EDCs and Phs even at the first minutes of chlorination. In contrast, the removal of BTs even at high chlorine doses of 245 mgCl2/lt ×min were very low. Regarding the effect of pH on chlorination efficiency, it seems that the removal of EDCs and Phs increases at pH values around 7. On the other hand, BTs removal is not significantly affected by the pH and TSS content of wastewater during chlorination. Furthermore UV disinfection at UV doses in the order of 40-150 mWs/cm 2 is not effective to remove Phs. From the target compounds tested, only ketoprofen and diclofenac exhibited appreciable removal only at higher UV doses. KEYWORDS: Benzotriazoles, Chlorination, Disinfection, Emerging contaminants, Endocrine disrupting chemicals, Pharmaceuticals, UV disinfection.