Photochemistry in Waste Treatment

Attention to the possibilities of using photochemical techniques to degrade undesirable compounds in water has been intermittent, although interest has increased rapidly in recent years (Zepp, 1988). Techniques that have been studied in the laboratory or pilot plant include use of soluble sensitizers, metal ions or oxides, and advanced oxidation processes (see Section 5.C.2) involving some combination of light, ozone, and H2O2. 

The use of sunlight, oxygen, and dissolved compounds capable of absorbing solar energy for the treatment of contaminated waters was first reported by Acher and Rosenthal (1977), who added methylene blue at 1.5-9X 10 M concentrations to samples of sewage, exposed the samples to sunlight, and followed the losses of 

Rosenthal. 1977. Dye-sensitized photooxidation—a new approach to the treatment of organic matter in sewage effluents. Water Res. 11, 557-562. 

Anjaneyulu, A. S. and U. V. Mallavadhani. 1988. Photosensitised reactions of aniline. Indian J. Chem. 27B, 154-155. 

Arnold, D. R. 1968. The photocycloaddition of carbonyl compounds to unsaturated systems the synthesis of oxetanes. Advan. Photochem. 6, 301-423. 

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