Comparative Studies of Photo-Initiated AOPs

Several examples of comparative studies of photo-initiated AOPs are collected in Tab. 7-3. 

From this table the following conclusions may be drawn. Firstly, the effectiveness of photo-initiated AOPs is strongly dependent on the nature of the substrates secondly, phenol and its halogenated derivatives are very sensitive to the photo-Fmton reaction and thirdly, this table demonstrates that the photo-Fenton, the H2O2-UV and the O3-UV AOP seem to be very efficient in oxidative degradation of various organic substrates. 

However, it must be stated that the reaction pathways are different during the various treatment routes. This fact manifests itself in the different number and types of intermediate oxidation products that have been identified with identical substrates during different AOPs (cf Rajeshwar, 1996). Further, the optimum conditions for a specific photo-initiated AOP treatment depend mainly on the nature of the waste or model water. For instance, H2O2-O3 treatment (without irradiation) can have advantages in the treatment of waters with high inherent UV ab- 

Substrate H2O2-UV OyUV O3-H2O2-UV H202 Fe /. Uy t ) TiOrUV H202- TiOrUVUV Refirences 

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