MINERALIZATION OF CYCLIC ORGANIC-WATER CONTAMINANTS BY THE PHOTO-FENTON REACTION - INFLUENCE OF STRUCTURE AND SUBSTITUENTS

Photochemical degradation of different aromatic and saturated cyclic o rganic substances (each containing six carbon atoms per molecule) in a queous solution by the Photo-Fenton reaction has been studied by monit oring TOC (Total Organic Carbon), UV-absorbance at 254 nm and consumpt ion of H2O2. Mineralization of phenol, hydroquinone, 4-chlorophenol an d 4-chloroaniline reached between 92% and 98% after 5 hours of illumin ation with a 250 W tungsten lamp. TOC-reduction of 3-nitroaniline and 4-nitroaniline was 76% and 74%, respectively. Cyclohexanol and cyclohe xanone showed only a very slight removal of TOC after this time. UV-ab sorbance (254 nm) of solutions containing aromatic substrates decrease d very rapidly at the beginning of the reaction suggesting a partial d estruction of the aromatic structure. Reasons especially for the selec tivity of TOC-degradation are discussed.