OXIDATION OF POLYNUCLEAR AROMATIC-HYDROCARBONS IN WATER .4. OZONE COMBINED WITH HYDROGEN-PEROXIDE

Three polynuclear aromatic hydrocarbons, fluorene, phenanthrene, and a cenaphthene, have been treated in water with ozone combined with hydro gen peroxide. The effect of hydrogen peroxide concentration, pH, and b icarbonate ions has been investigated. The process goes through direct and radical reactions in the case of fluorene and phenanthrene oxidat ion, while acenapthene is removed exclusively by direct ozonation. At concentrations of hydrogen peroxide higher than 10(-5) M, ozone mass t ransfer controls the process rate, regardless of pH. In any case, howe ver, the presence of hydrogen peroxide does not improve the oxidation rate compared to ozonation alone due to the importance of the direct r eactions. Intermediate compounds identified during oxidation with ozon e alone and combined with UV radiation or hydrogen peroxide are simila r and justify the high consumption of ozone in these processes.