Nitrotoluene destruction by UV-catalyzed fenton oxidation

The capacity of UV-catalyzed Fenton oxidation to destroy mono-, di- and trinitrotoluenes (MNT, DNT, TNT) in aqueous solution was evaluated. Mononitrotoluenes were rapidly destroyed by Fenton oxidation in the dark at pH 3.0 or by UV/Fenton oxidation without pH adjustment. UV/Fenton oxidation at pH 3.0 was most effective for DNT and TNT destruction. The number and position of nitro substitutions influenced oxidation rate: 2-nitrotoluene > 4-nitrotoluene > 2,4-dinitrotoluene > 2,6-dinitrotoluene > 2,4,6-trinitrotoluene. UV/Fenton oxidation mineralized more than 95% of the TNT in aqueous extracts of contaminated soil. While dissolved humic and fulvic acids differentially influenced destruction rate, total TNT destroyed after 4 h was not greatly affected. Our results demonstrated that UV-catalyzed Fenton oxidation effectively destroyed nitrotoluenes in water and aqueous extracts of contaminated soil.