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Metronidazole photodegradation in aqueous solution by using photosensitizers and hydrogen peroxide
Author(s) -
SánchezPolo Manuel,
RiveraUtrilla José,
PradosJoya Gonzalo,
OcampoPérez Raúl
Publication year - 2012
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.3750
Subject(s) - photodegradation , hydrogen peroxide , chemistry , aqueous solution , photochemistry , benzophenone , photosensitizer , photodissociation , photocatalysis , electron transfer , catalysis , organic chemistry
BACKGROUND: The effectiveness of UV radiation on the indirect photodegradation of metronidazole (MNZ) conducting a kinetic study of the process in the presence of radical promoter (H 2 O 2 ) and photosensitizer (Sens) promoters (duroquinone, tetrahydroxyquinone, tetrachloro‐1,4‐benzoquinone, 4‐carboxy‐benzophenone, 2,4‐dihydroxybenzophenone, 4‐hydroxybenzophenone, and 4,4′‐dihydroxybenzophenone) was investigated. RESULTS: The electron‐donating groups of photosensitizers may favor MNZ photodegradation through electron transfer. However, the photosensitizers studied showed low effectiveness of MNZ photodegradation in aqueous phase. The presence of H 2 O 2 substantially increased MNZ photodegradation rate, which was enhanced by increasing the concentration of hydrogen peroxide in the system. The contribution of direct photolysis of MNZ in the UV/H 2 O 2 system was drastically decreased with increasing H 2 O 2 concentrations. CONCLUSIONS: The low effectiveness obtained with most of the Sens used demonstrates that metronidazole cannot be photoxidized by indirect photooxidation in aqueous solution. Copyright © 2012 Society of Chemical Industry