Document Type


Publication Date

January 1987


Studies were conducted to determine the applicability of photooxidation for the degradation of selected hazardous and refractory organic compounds. These photochemical oxidation reactions occur through the transfer of energy from electronically excited sensitizer molecules which attain excited states by absorbing visible light energy. Optimum conditions for photooxidation were established based on sensitizer concentration and reaction pH for four polynuclear aromatic pollutants. The rate of photooxidation was found to be independent of the initial substrate concentration for methylene blue-sensitized reactions, and dependent on substrate concentration for solutions without a sensitizing dye. Photolysis of substrate mixtures established acridine and anthracene as photochemically active substrates. Photochemical reaction data suggest predictable trends in substrate reactivity based on pKa values of both sensitizer and substrate, initial substrate concentration and light absorbance characteristics. The photoproducts formed during the photolysis of acridine were found to be more toxic than the parent compound. These reaction products appear to be atable and warrant further study.