Pharmaceutical substances and personal care products are an emerging class of aquatic
contaminants that have been increasingly detected in ground and surface waters worldwide
(Halling-Sorensen et al., 1998; Stumpf et al., 1999; Heberer, 2002; Calamari et al., 2003).
Metronidazole is extensively used throughout Europe for treating infections caused by
anaerobic bacteria and protozoa (Lau et al., 1992). Metronidazole along with other
antibacterial and anticoccidial drugs with nitroimidazole structure is suspected of being
carcinogens and mutagents (Daeseleire et al., 2000). Being non-biodegradable and
soluble in water, metronidazole is not removed during conventional sewage treatment
(Kummerer et al., 2000); hence, it can accumulate in the aquatic environment.
Consequently, it is of concern to water utilities and a potential threat to drinking water
resources. One of the novel technologies for treating polluted sources of drinking water
and industrial wastewater is the advanced oxidation processes (AOPs) by which hydroxyl
radicals are generated in order to degrade organic pollutants (Ku et al., 1997). AOPs can
be applied to fully or partially oxidize pollutants, usually using a combination of two or
three oxidants. In this study the degradation of metronidazole using UV, UV/H2O2,
H2O2/Fe2+, and UV/H2O2/Fe2+ was investigated. Degradation rates and efficiencies were
compared between the UV photolysis and the three advanced oxidation processes
applied. Includes 9 references, figures.