Simple, sensitive and on-line fluorescence monitoring of photodegradation of phenol and 2-naphthol.

A simple molecular fluorescence spectrometer based on a hand-held CCD spectrometer was constructed for on-line monitoring of the photodegradation of pollutants. A high-pressure Hg vapour lamp was used for the UV photodegradation and simultaneously for the fluorescence excitation. Phenol and 2-naphthol were selected as the targets for this preliminary study. Using peak fluorescence, figures of merit for monitoring these two hydroxybenzene were obtained. Degradation efficiencies with different homogeneous photocatalyst systems were investigated, including UV only, UV/H(2)O(2) and UV/Fe(3+) degradation systems. The kinetics modelling showed that their photodegradation fitted the Langmuir-Hinshelwood model. Results showed that the proposed method is potentially applicable to both on-line real-time monitoring and field analysis.