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

The oxidation of metol (N-methyl-p-aminophenol) in aqueous solution by means of a UV/H2O2 system has been studied in the pH range 3.0–9.0. The results of the present investigation indicate that the pH, H2O2 and substrate concentration and oxygen presence significantly influence the system behaviour. Toxicity tests show that the H2O2 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.