Degradation of 32 emergent contaminants by UV and neutral photo-fenton in domestic wastewater effluent previously treated by activated sludge N. De la Cruz a,b , J. Gime ´nez b , S. Esplugas b , D. Grandjean c , L.F. de Alencastro c , C. Pulgarı´n a, * a Institut des Sciences et Inge ´nierie Chimiques, GGEC, EPFL, Ba ˆt. CH, 1015 Lausanne, Switzerland b Department of Chemical Engineering, Faculty of Chemistry, University of Barcelona, C/Marti I Franques 1, 08028 Barcelona, Spain c Central Environmental Laboratory, School of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Fe ´de ´rale de Lausanne, 1015 Lausanne, Switzerland article info Article history: Received 26 October 2011 Received in revised form 12 January 2012 Accepted 16 January 2012 Available online 24 January 2012 Keywords: Neutral photo-Fenton UV Emergent contaminants degradation Domestic wastewater decontamination abstract This study focuses on the removal of 32 selected micropollutants (pharmaceuticals, corrosion inhibitors and biocides/pesticides) found in an effluent coming from a municipal wastewater treatment plant (MWTP) based on activated sludge. Dissolved organic matter was present, with an initial total organic carbon of 15.9 mg L 1 , and a real global quantity of micropollutants of 29.5 mgL 1 . The treatments tested on the micropollutants removal were: UV-light emitting at 254 nm (UV 254 ) alone, dark Fenton (Fe 2þ,3þ /H 2 O 2 ) and photo-Fenton (Fe 2þ,3þ /H 2 O 2 /light). Different irradiation sources were used for the photo-Fenton experi- ences: UV 254 and simulated sunlight. Iron and H 2 O 2 concentrations were also changed in photo-Fenton experiences in order to evaluate its influence on the degradation. All the experiments were developed at natural pH, near neutral. Photo-Fenton treatments employing UV 254 , 50 mg L 1 of H 2 O 2 , with and without adding iron (5 mg L 1 of Fe 2þ added or 1.48 mg L 1 of total iron already present) gave the best results. Global percentages of micropollutants removal achieved were 98 and a 97% respectively, after 30 min of treat- ments. As the H 2 O 2 concentration increased (10, 25 and 50 mg L 1 ), best degradations were observed. UV 254 , Fenton, and photo-Fenton under simulated sunlight gave less promising results with lower percentages of removal. The highlight of this paper is to point out the possibility of the micropollutants degradation in spite the presence of DOM in much higher concentrations. ª 2012 Elsevier Ltd. All rights reserved. 1. Introduction Emergent organic contaminants (ECs) are in essence natural or synthetic substances which have the potential of entering the environment causing adverse ecological or human health effects, being most of them not regulated. The main sources of ECs are wastewater treatment plants for domestic sewage, wastewater from hospital effluents, chemical manufacturing plants, livestock and agriculture. This group covers products as human and veterinary pharmaceuticals, personal care products, surfactants and surfactant wastes, plasticizers and various industrial additives (Petrovic et al., 2003). Moreover, their * Corresponding author. Tel.: þ41 21 693 47 20; fax: þ41 21 693 56 90. E-mail address: cesar.pulgarin@epfl.ch (C.Pulgarı´n). Available online at www.sciencedirect.com journal homepage: www.elsevier.com/locate/watres water research 46 (2012) 1947 e1957 0043-1354/$ e see front matter ª 2012 Elsevier Ltd. All rights reserved. doi:10.1016/j.watres.2012.01.014