Elimination of drugs of abuse and their toxicity from natural waters by photo-Fenton treatment M. Catalá a , N. Domínguez-Morueco a , A. Migens a , R. Molina b , F. Martínez b , Y. Valcárcel c , N. Mastroianni d , M. López de Alda d , D. Barceló d,e , Y. Segura b, ⁎ a Department of Biology and Geology, Physics and Inorganic Chemistry, School of Experimental Sciences and Technology, Rey Juan Carlos University, C/ Tulipán s/n, E-28933 Móstoles, Madrid, Spain b Department of Chemical and Environmental Technology, School of Experimental Sciences and Technology, Rey Juan Carlos University, C/ Tulipán s/n, E-28933 Móstoles, Madrid, Spain c Research Group in Environmental Health and Ecotoxicology (ToxAmb), Department of Medicine and Surgery, Psychology, Preventive Medicine, Public Health, Immunology and Medical Microbiology, Faculty of Health Sciences, Rey Juan Carlos University, Avda. Atenas, s/n, E-28922 Alcorcón, Madrid, Spain d Department of Environmental Chemistry, Institute for Environmental Assessment and Water Research (IDAEA-CSIC), Jordi Girona 18–26, E-08034 Barcelona, Spain e Catalan Institute for Water Research (ICRA), H2O Building, Scientific and Technological Park of the University of Girona, Emili Grahit 101, 17003 Girona, Spain HIGHLIGHTS • Photo-Fenton reactions eliminate drugs of abuse in natural fluvial water. • High chemical degradation does not ensure toxicity elimination. • Catalyst loading is critical for an efficient toxicity elimination. • Toxicology testing is mandatory in decontamination assessment. abstract article info Article history: Received 12 December 2014 Received in revised form 23 February 2015 Accepted 10 March 2015 Available online 25 March 2015 Editor: Adrian Covaci Keywords: Pharmaceuticals Illicit substances Surface water Photo-Fenton Bioassay Drinking water This paper investigates the elimination of drugs of abuse from six different chemical classes and their metabolites in natural fluvial waters (nearby the output of a sewage system). Mineralization of these substances and toxico- logical characterization before and after treatment by a heterogeneous photo-Fenton system has been evaluated. This advanced oxidation technology was able to significantly reduce the concentration of the drugs of abuse in all the tested conditions (different hydrogen peroxide and catalyst loadings). However, toxicological analyses measured as inhibition of fern spore mitochondrial activity, showed only a complete elimination of acute and chronic toxicity when a higher solid catalyst loading was used (0.6 g/L). A lower catalyst loading of 0.2 g/L was not enough for toxicity elimination. These results evidence the need for combining toxicological tests and chemical analyses in order to establish the effectiveness of the water treatment technologies based on advanced oxidation processes. © 2015 Elsevier B.V. All rights reserved. 1. Introduction The presence of emerging microcontaminants, in particular drugs of abuse (DAs) (and/or their metabolites) in the water cycle as a con- sequence of their widespread consumption and poor elimination in the water treatment plants is an issue of important concern. As a result of their continuous introduction into the aquatic environment, these substances are behaving in a pseudo-persistent manner and currently represent a new class of environmental emerging pollutants that require emergency attention. In many cases, these substances are per- sistent, bioaccumulative and potentially toxic to aquatic organisms Science of the Total Environment 520 (2015) 198–205 Abbreviations: 6ACM, 6-acetylmorphine; ALCs, amphetamine-like compounds; ALP, alprazolam; AOP, advanced oxidation processes; BE, benzoylecgonine; CE, cocaethylene; CO, cocaine; DAs, drugs of abuse; DIAZ, diazepam; RW, raw water; EDDP, 2-ethylene 1,5- dimethyl 3,3-diphenylpyrrolidine; EPH, ephedrine; HER, heroin; LODet, limit of determina- tion; LOR, lorazepam; LSD OXO, 2-oxo-3-hydroxy-LSD; LSD, lysergic acid diethylamide; MA, methamphetamine; MDMA, 3,4-methylenedioxymethamphetamine or ecstasy; MOR, morphine; OH-THC, 11-hydroxy-Δ 9 -THC; PET, polyethylene terephthalate; SPE-LC–MS/ MS, on-line solid phase extraction-liquid chromatography–tandem mass spectrometry; SRM, selected reaction monitoring; STP, sewage treatment plant; THC, Δ 9 -tetrahydrocan- nabinol; THC-COOH, 11-nor-9-carboxy-Δ 9 -THC; TOC, total organic carbon. ⁎ Corresponding author. E-mail address: yolanda.segura@urjc.es (Y. Segura). http://dx.doi.org/10.1016/j.scitotenv.2015.03.042 0048-9697/© 2015 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv