Effect of Fe3+ on UV-illuminated ozonation of nitrophenolic compounds

Five nitrophenolic compounds were degraded by ozonation. UV illumination enhanced the degradation, particularly TOC elimination. The addition of Fe3+ further enhanced and completed the mineralization. The largest effect of Fe3+ was observed with 2,4-dinitrophenol which is most refractory to ozonation. UV and Fe3+ were effective on the degradation of aliphatic rather than aromatic intermediates. Some organic acid intermediates were found to be UV photosensitive in the presence of Fe3+ and their photodegradation rates were correlated with the effect of Fe3+ Hence the principal effect of Fe3+ on the UV-illuminated ozonation is attributed to photodegradation of aliphatic intermediates by Fe3+ complex.