Kinetics of the sensitized photodegradation of nonylphenol

Article

Summary *

Nonylphenol(nonyl-P) belongs to the classification of persistent organic pollutants. In this work we demonstrate that the contamination suffers photooxygenation when exposed to visible light Eosin-photosensitized irradiation. The mechanism was identified as a singlet molecular oxygen-mediated photooxidation. Rate constants for the process, determined by time-resolved phosphorescence detection of singlet molecular oxygen, are in the range 105-107 M-1 s-1, depending on the characteristics of the reaction medium. The photooxidative process is more efficient when performed in highly polar alkaline medium. The aggregation of nonyl-P molecules in pure water decreases the rates of sensitized photooxidation of nonyl-P and also those of polychlorophenolic contaminants, employed as photooxidizable model compounds, when photolyzed in the presence of nonylphenol. These results are discussed in terms of a micellar effect. Information provided by the agent in SIGEVA