Photolysis of Pentachlorophenol in Water

Abstract

When a dilute aqueous solution (100 ppm) of pentachlorophenol (PCP) was irradiated with sunlight or UV light, the photodegradation products were found to be chlorinated phenols, tetrachlorodihydroxyl benzenes and non-aromatic fragments such as dichloromaleic acid. Subsequent irradiation of the tetrachlorodiols resulted in the formations of hydroxylated trichlorobenzoquinones, trichlorodiols, dichloromaleic acid and non-aromatic fragments. Dichloromaleic acid, when irradiated, produced chloride ions and carbon dioxide. Prolonged irradiation of PCP or its photodegradation products yielded colorless solutions containing no ether-extractable volatile materials; and evaporation of the aqueous layer left no observable polymeric residue such as humic acid. Octachlorodibenzo-p-dioxin was formed when a high concentration of the sodium salt of PCP was irradiated.