Determination of degradation products of alkylphenol polyethoxylates in municipal wastewaters and rivers in Tokyo, Japan

An analytical method for the simultaneous determination of nonylphenoxy acetic acid (NP1EC), nonylphenol monoethoxy acetic acid (NP2EC), nonylphenol (NP), octylphenol (OP), and nonylphenol monoethoxylate (NP1EO) was developed. The method was applied to environmental samples to demonstrate the distribution and behavior of nonylphenol polyethoxylates and their degradation intermediates in aquatic environments in Tokyo, Japan. In sewage treatment plants, more than 85% of NP, OP, and NP1EO were removed, whereas NP1EC and NP2EC were generated during the treatment. Concentrations of NP1EC and NP2EC in secondary effluents (1.9-2.9 mug/L) were higher than those of NP and NP1EO (0.12-0.63 mug/L). In river waters, NP1EC and NP2EC concentrations (0.11-2.8 mug/L) were higher than NP and NP1EO concentrations (<0.015-3.4 mug/L), with some exceptions. In surface sediments, neither NP1EC nor NP2EC was detectable (<0.01 mug/g dry wt) whereas NP and NP1EO were detected significantly (0.03-1.82 mug/g dry wt and 0.04-0.46 mug/g dry wt, respectively).