Metronidazole photodegradation in aqueous solution by using photosensitizers and hydrogen peroxide Article uri icon

abstract

  • 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 2O 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 2O 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 2O 2 system was drastically decreased with increasing H 2O 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. © 2012 Society of Chemical Industry.

publication date

  • 2012-01-01