[Sorption of 17beta-estradiol to soils and sediment and influence of pig manure DOM].

Natural steroid estrogens such as 17beta-estradiol (E2) with low concentrations (ng x L(-1)) can adversely affect the reproductive health of aquatic organisms. Batch equilibrium experiments were conducted to quantify the sorption of E2 to two agricultural soils and a river sediment from different physiographic regions in northern China, a critical step in predicting transport of estrogens in runoff from agricultural fields. Meanwhile, the effect of pig manure and its compost borne dissolved organic matter (DOM) on E2 sorption was investigated. The Freundlich isotherm provided a good fit to model the sorption of E2 to agricultural soils and the sediment (R2 > 0.76). E2 adsorption nonlinearity was found for alluvial soil, black soil and the sediment, most isotherm deviation from linearity occurred in black soil (n = 0.74). The sorption of E2 to agricultural soil and sediment was correlated to the organic carbon content of each soil/sediment (P<0.05) with K(f) values ranging from 26.2 to 57.5. It was also found that the presence of DOM decreased estrogen sorption in soils and sediment, especially manure compost borne DOM. These results suggest that E2 was mostly adsorbed on organic matter in soil and sediment, and coexisted pig manure DOM could increase mobility at low concentration level and enhance the risk of E2 transport to ground and surface waters.