Removal of compounds used as plasticizers and herbicides from water by means of gamma irradiation José Rivera-Utrilla a, ⁎, Mahmoud M. Abdel daiem b , Manuel Sánchez-Polo a , Raúl Ocampo-Pérez c , Jesús J. López-Peñalver a , Inmaculada Velo-Gala a , Antonio J. Mota a a Inorganic Chemistry Department, Faculty of Science, University of Granada, 18071 Granada, Spain b Environmental Engineering Department, Faculty of Engineering, Zagazig University, 44519 Zagazig, Egypt c Center of Research and Postgraduate Studies, Faculty of Chemical Science, Autonomous University of San Luis Potosí, Av. Dr. M. Nava No.6, San Luis Potosí SLP 78210, Mexico HIGHLIGHTS • Degradation of plasticizers and herbi- cides using gamma radiation was stud- ied. • Dose constants, removal percentages, and radiation-chemical yields were de- termined. • The reaction rate constants of HO • ,e aq - , H • with the pollutants were deter- mined. • The elimination of the pollutants main- ly followed the oxidative pathway. • The evolution of chemical oxygen de- mand and toxicity was analyzed. GRAPHICAL ABSTRACT abstract article info Article history: Received 18 March 2016 Received in revised form 7 June 2016 Accepted 15 June 2016 Available online xxxx Editor: Simon Pollard Gamma radiation has been used to induce the degradation of compounds used as plasticizers and herbicides such as phthalic acid (PA), bisphenol A (BPA), diphenolic acid (DPA), 2,4-dichlorophenoxy-acetic acid (2,4-D), and 4-chloro- 2-methylphenoxyacetic acid (MCPA) in aqueous solution, determining the dose constants, removal percentages, and radiation-chemical yields. The reaction rate constants of hydroxyl radical (HO • ), hydrated electron (e aq - ) and hy- drogen atom (H • ) with these pollutants were also obtained by means of competition kinetics, using 3-aminopyridine and atrazine as reference compounds. The results indicated that the elimination of these pollutants with gamma ra- diation mainly follows the oxidative pathway through reaction with HO • radicals. The degradation by-products from the five pollutants were determined, detecting that the hydroxylation of the corresponding parent compounds was the main chemical process in the degradation of the pollutants. Moreover, a high decrease in the chemical oxygen demand has been observed for all pollutants. As expected, the degradation by-products generated by the irradiation of PA, BPA and DPA showed a lower toxicity than the parent compounds, however, in the case of 2,4-D and MCPA irradiation, interestingly, their by-products were more toxic than the corresponding original compounds. © 2016 Elsevier B.V. All rights reserved. Keywords: Gamma radiation Herbicides Plasticizers Advanced oxidation/reduction processes (AORPs) Water pollutants removal Science of the Total Environment 569–570 (2016) 518–526 ⁎ Corresponding author. E-mail address: jrivera@ugr.es (J. Rivera-Utrilla). http://dx.doi.org/10.1016/j.scitotenv.2016.06.114 0048-9697/© 2016 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv