Degradation and monitoring of acetamiprid, thiabendazole and their transformation products in an agro-food industry effluent during solar photo-Fenton treatment in a raceway pond reactor Irene Carra a , Carla Sirtori b , Laura Ponce-Robles a,c , José Antonio Sánchez Pérez a , Sixto Malato a,c , Ana Agüera a,⇑ a CIESOL, Joint Centre of the University of Almería-CIEMAT, La Cañada de San Urbano, 04120 Almería, Spain b Instituto de Química-UFRGS, Av. Bento Gonçalves, 9500, Bairro: Agronomia, 91509-900 Porto Alegre, RS, Brazil c Plataforma Solar de Almería (CIEMAT), Carretera Senés, km 4, 04200 Tabernas, Almería, Spain highlights  Raceway ponds are an efficient technology to remove micropollutants by photo-Fenton.  An analytical strategy was developed for identification of transformation products.  14 TPs of acetamiprid and thiabendazole were monitored in real agro-food effluent.  The process operation depends on TPs degradation since they are also persistent. graphical abstract article info Article history: Received 26 October 2014 Received in revised form 22 January 2015 Accepted 1 March 2015 Handling Editor: Jun Huang Keywords: Pesticides Transformation products Wastewater treatment Liquid chromatography Mass spectrometry abstract In this study, pesticides acetamiprid and thiabendazole and their transformation products (TPs), seven from each pesticide, were successfully monitored during solar photo-Fenton treatment in a real sec- ondary effluent from an agro-food industry spiked with 100 lgL 1 of each pesticide. To this end, a highly sensitive procedure was developed, based on liquid chromatography (LC) coupled to hybrid quadrupole- linear ion trap mass spectrometry (QqLIT-MS). In addition, finding low-cost and operational technology for the application of AOPs would then facilitate their use on a commercial level. Simple and extensive photoreactors such as raceway pond reactors (RPRs) are therefore proposed as an alternative for the application of solar photo-Fenton. Results showed that high degradation could be achieved in a complex water matrix (>99% TBZ and 91% ACTM in 240 min) using a 120-L RPR pilot plant as novel technology. The analyses indicated that after the treatment only three TPs from ACTM were still present in the effluent, while the others had been removed. The study showed that the goal of either just removing the parent compounds, or going one step further and removing all the TPs, can significantly change the treatment time, which would affect process costs. Ó 2015 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.chemosphere.2015.03.001 0045-6535/Ó 2015 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Tel.: +34 950 015531. E-mail address: aaguera@ual.es (A. Agüera). Chemosphere 130 (2015) 73–81 Contents lists available at ScienceDirect Chemosphere journal homepage: www.elsevier.com/locate/chemosphere