Catolica

Applied Catalysis B: Environmental 89 (2009) 255–264

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Applied Catalysis B: Environmental
journal homepage: www.elsevier.com/locate/apcatb

Solar photocatalytic degradation of persistent pharmaceuticals at pilot-scale: Kinetics and characterization of major intermediate products
´ ´ ` ´ Jelena Radjenovic a, Carla Sirtori b, Mira Petrovic a,c,Damia Barcelo a,d, Sixto Malato b,*
a

Department of Environmental Chemistry, IDAEA-CSIC, c/Jordi Girona 18-26, 08034 Barcelona, Spain Plataforma Solar de Almerı´a (CIEMAT), Carretera Senes, Km. 4, 04200 Tabernas (Almerı´a), Spain c Institucio Catalana de Reserca i Estudis Avanzats (ICREA), Barcelona, Spain d ` ´gic de la Universitat de, Girona, Pic de Peguera, 15, 17003 Girona, Spain InstitutCatala de Recerca de l’Aigua (ICRA), Parc Cientı´fic i Tecnolo
b

A R T I C L E I N F O

A B S T R A C T

Article history: Received 17 December 2008 Received in revised form 6 February 2009 Accepted 13 February 2009 Available online 27 February 2009 Keywords: Acetaminophen Atenolol Intermediate products Solar TiO2 photocatalysis Solar photo-Fenton UPLC-QqToF–MS

The technical feasibility andperformance of photocatalytic degradation of anti-inflammatory drug acetaminophen (ACTP) and b-blocker atenolol (ATL) have been studied in a well-defined system of a pilot-plant scale Compound Parabolic Collectors (CPCs) under natural illumination. Heterogeneous photocatalysis with titanium dioxide (TiO2) and homogeneous photocatalysis by photo-Fenton were investigated with two different matrices:distilled water and synthetic municipal wastewater treatment plant effluent (S.E.). The initial concentrations of the pharmaceuticals studied were 10 mg LÀ1, whereas the concentrations of the catalysts employed were 200 mg LÀ1 of TiO2 and 5 mg LÀ1 of iron. Total disappearance of the parent compounds and discreet mineralization were attained in all experiments. Furthermore, kinetic parameters, releaseof heteroatoms and formation of carboxylic acids are discussed. The main intermediate products of photocatalytic degradation of atelonol has been structurally elucidated by tandem mass spectrometry (MS2) experiments performed at quadrupole-time of flight (QqToF) mass analyzer coupled to ultra-performance liquid chromatograph (UPLC). Six transformation products were characterized, formed byconsecutive attacks of hydroxyl (OH) radical in concomitance with the disappearance of the primary compound. The proposed TiO2 and photo-Fenton degradation route of ATL is reported for the first time. ß 2009 Elsevier B.V. All rights reserved.

1. Introduction The presence of pharmaceuticals in the environment is an issue receiving growing attention worldwide. Possible adverse effects thatpharmaceuticals might have in the ecosystems are still unknown, whereas many studies have been conducted on their occurrence in the aquatic and terrestrial environmental compartments [1–3]. Acetaminophen (ACTP) is a commonly used analgesic. After being processed in liver ACTP is excreted in urine [4]. Atenolol (ATL) is a b1 receptor specific antagonist, used primarily to treat cardiovascular diseases. Afterhuman consumption, it is excreted also via urine [5], with a small percentage of ATL-glucuronide (0.8– 4.4%) and hydroxyATL (1.1–4.4%, hydroxylation of the benzilic position) [6]. The reported removals in sewage treatment plants (STPs) are varying from almost complete for ACTP [7], to no removal or partial removal reported for ATL [7,8]. As far as their photolysis in natural waters is concerned, Liuet al. [9] observed

* Corresponding author. Tel.: +34 950387940; fax: +34 950365015. E-mail address: Sixto.Malato@psa.es (S. Malato). 0926-3373/$ – see front matter ß 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.apcatb.2009.02.013

slow direct photolysis of ATL in water. Andrisano et al. [10] noticed an increase in the photodegradation rate of ATL with the decrease in pH in a...