Comparison among Fenton-related processes to remove 2,4-dinitrophenol

Several Fenton-related oxidative processes, UV/H2O2, Fenton reaction, Photo-Fenton-type, and Photo-Fenton have been compared to isolate the one that can effectively remove 2,4-dinitrophenol (DNP). The following criteria were adopted to screen the best oxidative process in terms of removal of DNP: residual percentage of DNP, residual percentage of ADMI color value and residual percentage of dissolved organic carbon (DOC). Results show that the Photo-Fenton process outranks among others based on above-mentioned criteria. Initially, the Photo-Fenton process gives the same oxidative capability as the Fenton reaction. As reaction progresses, the Photo-Fenton process outperforms others because the irradiation energy from UV light stimulates the regeneration of ferrous ion, resulting in more hydroxyl radicals released from H2O2, and further enhances the removal of DNP. In addition, The analysis of pseudo first-order rate constants indicates that the removal rate of DOC is the limiting step in the Photo-Fenton process.