Use of dye sensitized photooxidation is potentially a low cost means of degrading many of the hazardous compounds found in wastewaters. This study investigated the use of methylene blue as a sensitizer to degrade ortho-, meta-, and para-cresol, carbofuran and acrylonitrile. Significant reductions were found when aqueous solutions of the cresol isomers and carbofuran were illuminated and aerated in the presence of methylene blue. An average of 78% reduction of cresol was observed in seven hours. Carbofuran showed an average percent reduction of 56% in two hours. No loss was observed when the dye was absent. Acrylonitrile was found to be volatile and was stripped from solution by aeration. / M.S.