title: Theoretical and experimental formation of low chlorinated dibenzo-p-dioxins and dibenzofurans in the Fenton oxidation of chlorophenol solutions.
abstract: The formation of chlorinated and non-chlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) has been experimentally investigated after the Fenton oxidation of 2-chlorophenol (2-CP, 15.56 mM) aqueous solutions by assessing the influence of iron concentration (0.09-2.88 mM), hydrogen peroxide dose (40.44-202.20 mM), temperature (20-70 °C) and chloride concentration (0-56.35 mM). The presence of chloride in the medium together with room temperature and substoichiometric Fenton conditions (40.44 mM H2O2) led to an increase in total PCDD/Fs concentration from less than 1 ng L(-1) to 2 μg L(-1). Results showed a dominance of the dichlorinated species (DCDD/Fs) in the homologue profile of total PCDD/Fs reaching values up to 1.5 μg L(-1). Furthermore, the products distribution exhibited a gradual decrease in the homologue concentration as the chlorination degree increased from di-to octachloro-substituted positions. Considering the characteristics of the reaction medium, the experimental results, and the information gathered in bibliography with regard to the generation of active radicals from 2-chlorophenol, a mechanism describing the formation of low chlorinated PCDD/Fs in a Fenton oxidizing aqueous system has been proposed.
authors.affiliation: Departamento de Ingenierías Química y Biomolecular, ETSIIyT, Universidad de Cantabria, Avda. de los Castros, 39005, Santander, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Fernández-Castro
authors.affiliation: Departamento de Ingenierías Química y Biomolecular, ETSIIyT, Universidad de Cantabria, Avda. de los Castros, 39005, Santander, Spain.
authors.forename: M Fresnedo
authors.initials: MF
authors.lastname: San Román
authors.affiliation: Departamento de Ingenierías Química y Biomolecular, ETSIIyT, Universidad de Cantabria, Avda. de los Castros, 39005, Santander, Spain. Electronic address: ortizi@unican.es.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Ortiz
mesh_terms: D001572:Benzofurans; D002733:Chlorophenols / Q000737:chemistry*; D000072338:Dibenzofurans, Polychlorinated / Q000737:chemistry*; D054879:Halogenation; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D008956:Models, Chemical; D010084:Oxidation-Reduction; D000072317:Polychlorinated Dibenzodioxins / Q000737:chemistry*; D012996:Solutions; D013696:Temperature
chemical_list: D001572:Benzofurans; D002733:Chlorophenols; D000072338:Dibenzofurans, Polychlorinated; C045076:Fenton's reagent; D000072317:Polychlorinated Dibenzodioxins; D012996:Solutions; D006861:Hydrogen Peroxide; D007501:Iron; C030683:2-chlorophenol
keywords: 2-Chlorophenol; Dibenzo-p-dioxins; Dibenzofurans; Fenton oxidation; Reaction mechanism