1. 3 rd EUROPEAN CONFERENCE ON ENVIRONMENTAL APPLICATIONS OF ADVANCED OXIDATION PROCESSES (EAAOP3), ALMERÍA (SPAIN) 27-30 October 2013 Removal of Dexamethasone Sodium Phosphate (DSP) in liquid phase by Using Advanced Oxidation Processes (AOPs) S. SULAIMAN 1, L. SCRANO 2, F. LELARIO 1, R. KARAMAN 3, S.A. BUFO 1 1 Department of Science and 2 Department of European cultures (DICEM), University of Basilicata, 85100 Potenza, Italy. 3 Faculty of Pharmacy, Al-Quds University, Jerusalem, Palestine. The occurrence and the fate of pharmaceutical residues in the environment during the last decade has attracted an increasing interest and has posed a new challenge to remediate water polluted with this kind of substances. Removal of many of pharmaceutical compounds, during municipal wastewater treatment, has showed to be incomplete and sometimes ineffective. Some authors reported that residues of these compounds have been detected in surface waters in concentrations ranging from the ng L -1 up to the mg L -1 level [1]. Advanced oxidation processes (AOPs), as photolysis and photo-catalysis, could be viable methods for the removal of organic pollutants and other contaminants from the surface, soil and wastewater [2 - 4]. In the present work, it was shown the application of AOPs for DSP removal from water, a synthetic adrenocortical steroid pharmaceutical compound, used a lot to treat inflammation, allergy and diseases related to adrenal cortex insufficiency. CHEMICALS: DSP (99%) from Birzeit Pharmaceuticals company/ Palestine; Acetonitrile HPLC-grade and Formic acid from Sigma-Aldrich; TiO 2 P-25 from Degussa (obtained by aerosil process for nanoparticles’ production ). IRRADIATION APPARATUS: Heraeus Suntest CPS Instrument equipped with Xenon Arc lamp (1.8 KW) (Fig.1) ANALITICAL EQUIPMENTS: LC system coupled to a hybrid quadrupole ion trap (LTQ)– Fourier Transform Ion Cyclotron Resonance (FT-ICR) Mass Spectrometer (Thermo Fisher Scientific- Bremen, Germany ). Kinetic constants were calculated from the slope of the linear equation obtained plotting the natural logarithm of the actual DSP concentration versus the testing time (Fig. 2). Independently of the process assessed, data of the DSP degradation fitted well a pseudo first order kinetic curve. Photolysis half-life was 69 min while decreased up to 19.8 min. by using TiO 2. Photo-degradation by-products were detected by using LC/FTICR-ESI-MS. The photoproducts identified, are reported in Table 1. …..IN CONCLUSION Results confirms that photocatalysis is an important process to destroy such kind of drugs in aquatic bodies. We can suggest the use of this kind of treatment for further purification of effluents from waste water treatment plants. [1] Ternes TA. Occurrence of drugs in German sewage treatment plants and rivers. Water Res. 1998;32(11): 3245–60. [2] Charles E. West and Steven J. Rowland. (2012. Environ. Sci. Technol. 46, 4749 - 4756. [3] Metcalfe, C.D., Koenig, B.G., Bennie, D.T., Servos, M., Ternes, T.A., Hirsch, R. (2003). Environ. Toxicol. Chem. 22, 2872–2880. [4] Benotti, M.J., Vanderford, B.J., Holady, J.C., Stanford, B.D., Snyder, S.A.(2009). Environ. Sci. Technol. 43, 597–603. [5] Gentile, D. M., Tomlinson, E. S., Maggs, J. L., Park, B. K., Back, D., Dexamethasone metabolism by human liver in vitro. Metabolite identification and inhibition of 6- hydroxylation. J. J. Pharmacol. Exp. Ther. (1996), 277(1): 105-112. Table 1. Intermediate photoproducts of DSP under different treatments. Acknowledgements: This work was supported by the European Commission in the framework of the Project “Diffusion of nanotechnology based devices for water treatment and recycling - NANOWAT” (ENPI CBC MED I-B/2.1/049, Grant No. 7/1997). Fig. 2- DSP photolysis and photocatalysis kinetics Fig.1 Heraeus Suntest CPS Structure Molecular formula [M+H] + Accurate m/z [M+H + ] Error (ppm) RT (min) Type of Degradation SunlightSunlight+TiO 2 C 22 H 29 O 5 F393.20740+ 0.560012.73 × × C 22 H 29 O 5 373.20129 + 0.9100 12.77×× C 20 H 25 O 3 F 333.18634+ 0.870014.58 ×× C 20 H 24 O 3 313.18002+ 0.630014.53×× …..RESULTS Four photoproducts were identified, and were the same from both processes (photolysis and photocatalysis). The differences were only in the half-life t 1/2 and in kinetic constant k. The degradation products are less toxic than original molecule [5] and their persistence in the environment is very short because all metabolites derived from photolysis and photocatalysis were completely mineralized after 5 and 3 hours respectively.