J. Kiwi, A. López, V. Nadtochenko
Apr 19, 2000
Citations
7
Influential Citations
313
Citations
Quality indicators
Journal
Environmental Science & Technology
Abstract
Orange II, the 4-(2-hydroxy-1-naphthylazo)benzenesulfonic acid Na-salt, was taken as a model for the oxidation of organic compounds in photoassisted Fenton process in the presence of Cl--anion in solution. The HO• radicals seem to originate due to the photolysis of Fe(OH)2+ complexes in solution, whereas the Cl2-• radical was a product of the photolysis of the FeCl2+ complexes. The rate constants for the reaction of HO• and Cl2-• radicals with Or II were determined by laser kinetic spectroscopy: kOH•+OrII = 6.0 × 109(M s)-1 and kCl2•+OrII = 3.7 × 107 (M s)-1. A significant decrease in the rate of decoloration was observed for Orange II upon addition of Cl- (10 mM), but further addition of Cl- only marginally affected the latter reaction rate. Chlorinated hydrocarbons are observed as the products of Orange II oxidation in photoassisted and dark Fenton processes in the presence of Cl- anions. Light irradiation was observed to decrease the amount of chlorinated organic products (AOX) in solution as compared...