Kinetics of the photosensitized oxidation of polychlorophenols in alkaline aqueous solution

Abstract

The dye sensitized photooxidation of 2,4‐dichlorophenol, 2,6‐dichlorophenol and 2,4,6‐trichlorophenol in alkaline aqueous solution was studied. The inhibition of photo‐oxidation by N‐ 3 suggests that the reaction occurs via a singlet oxygen mechanism. The polychlorophenols give different proportions of reaction with and quenching of singlet oxygen. The total rate constant for the process is in the order of 108 to l09 M‐1s‐1. A charge transfer mechanism for quenching of singlet oxygen by the phenols is proposed. A quantum yield of 0.01 for polychlorophenol degradation was estimated.