Photocatalytic degradation of trinitrotoluene and trinitrobenzene: Influence of hydrogen peroxide

The degradation of 2,4,6-trinitrotoluene (TNT) and 1,3,5-trinitrobenzene (TNB) was studied in irradiated (lambda > 320 nm) homogeneous solutions and in TiO2 suspensions by varying the concentration of hydrogen peroxide and the pH. Photodegradation of TNT occurs rapidly in both homogeneous and heterogeneous media. In TiO2 suspensions the degradation rate of TNT is enhanced significantly compared with the homogeneous solutions at all pH values investigated. Over almost the entire pH region studied, the addition of hydrogen peroxide to the suspensions results in decreasing reaction rates. Under the experimental conditions investigated, TNB is degraded significantly slower than TNT in all cases.