Chemical degradation of aromatic amines by Fentonʹs reagent

The potential of the oxidation of various carcinogenic aromatic amines by Fentonʹs reagent [Fe(II) + H2O2] for liquid waste treatments was assessed. The insoluble products yielded were amenable to oxidation to ring-cleavage products and ultimately to carbon dioxide. Mineralization was confirmed by mass spectrometry. The kinetics of precipitation was determined from scattering measurements, at 500 nm, of the insoluble substance produced as a function of time. The influence of experimental variables on the removal of aromatic amines from aqueous solutions by formation of insoluble products and ring-cleavage products was established. Complete removal took about 1 and 3 h of treatment overall for the formation of insoluble products and ring-cleavage products, respectively. Residual hydrogen peroxide, iron(II) concentration, chemical oxygen demand and chromatographic techniques were used to determine when the reaction was finished. The iron(II) concentration was found to be crucial to the nature of the end products obtained (insoluble products, ring-cleavage products, CO2).