The oxidation of metol (N-methyl-P-aminophenol) in aqueous solution by UV/H2O2 photolysis

Abstract The oxidation of metol ( N -methyl- p -aminophenol) in aqueous solution by means of a UV/H 2 O 2 system has been studied in the pH range 3.0–9.0. The results of the present investigation indicate that the pH, H 2 O 2 and substrate concentration and oxygen presence significantly influence the system behaviour. Toxicity tests show that the H 2 O 2 photolytic process is capable of reducing the toxicity of metol aqueous solutions. The kinetic constant of the attack of HO radicals to the substrate has been also estimated through the adoption of a simplified model.