BEHAVIOR OF ALKYLPHENOL POLYETHOXYLATE SURFACTANTS IN THE AQUATIC ENVIRONMENT .2. OCCURRENCE AND TRANSFORMATION IN RIVERS

The behaviour of nonylphenol polyethoxylate surfactants (NPnEO) and their metabolites in the Glatt River, Switzerland was studied. Discharge of secondary effluents from municipal sewage plants into the river was the predominant source of the investigated compounds. The majority of nonylphenolic compounds in the Glatt River were in the form of persistent metabolites, the most abundant being nonylphenoxy carboxylic acids. Distribution of the various classes of nonylphenolic compounds in the river was influenced to differing extents by biological and physico-chemical processes and was dependent on the compound class and the season. Biotransformation appears to be the predominant mechanism determining the fate of nonylphenolic compounds. High concentrations of lipophilic metabolites in river sediments indicate the importance of physico-chemical processes on the distribution of the nonylphenolic chemicals in natural waters.