Abstract
Alkylphenol polyethoxylate (APE) and their metabolites were determined in the aquatic environment in Nagoya city. The persistent metabolites of APE, namely nonylphenol tetra-,tri -,di- and monoethoxylate(NPI-4EO), nonylphenol(NP) and octylphenl(OP) were determined in effluents of municipal sewage-treatment plants and river waters by HPLC. In many samples NP1-4EO concentrations were higher than NP. It seems that a predominant source of the invesitigated compounds in river waters was the effluents of municipal sewage-treatment plants. Nonylphenol polyethoxylate (NPnEO : n≥5) was not detected in effluents of municipal sewage-treatment plants, but was detected only in river water receiving untreated municipal wastewaters.
NPnEO, NP1-4EO, NP and OP were found in sediments at concentration levels of a few hundreds times higher than those levels in river waters, indicating their accumulation in sediments. NP concentrations were higher than NP1-4EO concentrations in sediments.
These metabolites, particularly NP, are more toxic to aquatic organisms than the parent compounds, consequently there are public concerns about their environmental effects. This research demonstrates that further investigation on the behaviour of APE and their metabolites is necessary.
