Primary photochemical reactions in the photo-Fenton system with ferric chloride. 1. A case study of xylidine oxidation as a model compound
Environmental contamination in groundwater involving a variety of nonbiodegradable toxic xylidines from industrial or military effluents is a matter of growing concern. Besides the traditional nondestructive treating methods to remove these substances in water bodies, the application of advanced oxidation technologies such as Fenton photoassisted reactions seems a suitable way to remove and mineralize these contaminants and is the aim of the present study. Primary photochemical reactions in the water solutions of ferric chloride complexes in the absence and in the presence of H2O2 were examined by laser photolysis (λ = 347 nm) using xylidine (2,4-dimethylaniline, XYL) as probe molecule. The Cl2•- radicals are formed as a result of the reaction of Cl• atoms and OH• radicals produced during the photodissociation of ferric chloride and ferric hydroxy complexes in the presence of Cl- anion. The oxidation of xylidine by Cl• or Cl2•- lead to the formation of the XYL+ radical−cation [C8H9NH2]•+, having an absorp...