Synergistic effects of 4-nitrophenol degradation using gamma irradiation combined with a advanced oxidation process

The radiation-induced degradation of 4-nitro-phenol (4-NP) was performed in combination with a Fenton reagent, H2O2, and TiO2 nanoparticles to investigate the synergetic effects of radiolytical degradation combined with other advanced oxidation processes. The experimental results indicated that the degradation efficiency of 4-NP was 87.5, 57.4, and 41.0 % at a dose of 20 kGy when its initial concentration was 100, 200, and 350 mg/L, respectively. Radiation combined with H2O2, the Fenton method, and TiO2 remarkably increased the degradation efficiency of 4-NP, showing the synergetic effects. Radiation may enhance the biodegradability of 4-NP, suggesting that it has the potential to be used as a pretreatment method in combination with the biological method for the treatment of industrial wastewater containing toxic organic pollutants. Major intermediates during the 4-NP degradation process were identified and a possible degradation pathway was tentatively proposed.