Pentachlorophenol decomposition by electron beam process enhanced in the presence of Fe(III)-EDTA

This study focuses on the enhanced decomposition of pentachlorophenol (PCP) in an electron beam (E-beam) process. To attain this objective, we investigated a synergistic effect of ferric-ethylenediamineacetate (Fe(III)-EDTA) and H2O2 as additives to produce additional hydroxyl radical (OH) at low dose. In this process, aqueous electron and hydrogen atom rapidly react with O2 molecules, thereby forming hydroperoxyl/superoxide anion radical (HO2/O2-), which reduces the Fe(III)-EDTA into Fe(II)-EDTA. Further OH is produced by a well-known Fenton-like reaction of Fe(II)-EDTA with H2O2 formed newly in E-beam. The complete decomposition of the initial PCP at 0.1 mM was enhanced even at very low dose (<10 kGy) with 20 μM Fe(III)-EDTA and H2O2 less than 1 mM. This observation was supported by the increased amount of Cl− produced by the decomposition of PCP. Thus, in the presence of Fe(III)-EDTA during E-beam irradiation, the HO2/O2--driven Fenton-like reaction produces much more OH, which is significant for the complete degradation of PCP.