The fate of estrogenic compounds in the aquatic environment: sorption onto organic colloids

In this study, sorption of some estrogens and estrogenic compounds onto several organic colloids was examined using fluorescence quenching techniques. Selected organic colloids included humic substances of several sources, Aldrich humic acid (AHA), Suwannee River humic acid (SRHA), Suwannee River fulvic acid (SRFA), and Nordic fulvic acid (NFA). Polysaccharides, alginic acid (AA) and dextran (Dex), and tannic acid (TA) were also selected. 17beta-estradiol (E2), 17alpha-ethynylestradiol (EES), and estriol (E3) were selected as estrogens. Nonylphenol (NP), octylphenol (OP), and dibutylphthalate (DBP) were selected as estrogenic compounds. For most of the selected compounds, the sorption coefficients were in the order of TA > humic acids (SRHA or AHA) > fulvic acids (NFA or SRFA) > AA. The smallest or no significant sorption onto dextran was found for selected estrogens and estrogenic compounds. Comparing those compounds, neither a significant trend nor linear correlation with Log K(ow) was found. The resulting sorption coefficients for humic substances and TA suggested approximately 15 to 50% of the estrogens and estrogenic compounds were bound in typical natural water of 5 mg TOC/L and significant effects on the removal of them by water treatment processes, toxicity, or bioavailability were suggested.