Studies on photo-degradation of 2,4-dinitro toluene in aqueous phase.

The efficiency of different photo-degradation processes was evaluated for degrading 2,4-dinitro toluene (DNT) in aqueous phase. The rate and extent of DNT degradation and removal of total organic carbon (TOC) and total nitrogen (TN) contents were compared for direct photolytic and photo-oxidative reactions using various concentrations of H2O2 and Fenton's reagent with a 125 W medium pressure UV lamp. DNT was degraded rapidly under photo-oxidative conditions. Complete destruction was obtained using Fenton's reagent, wherein 100 ppm of DNT was degraded within 60 min of irradiation time. Removal of TOC and TN contents in the photo-Fenton system was 96% and 57%, respectively, after 2 h of UV irradiation. Degradation of DNT followed first order reaction kinetics. Photo-Fenton oxidation is found to be the most suitable technique to degrade DNT in aqueous phase.