天然类固醇雌激素如17β-雌二醇(E2)在极低质量浓度下(ng.L-1)即可干扰水生生物的生殖功能.为准确预测E2向水体迁移,通过摇床实验研究了E2在中国北方3种不同土壤/沉积物表面的吸附特征,同时探讨了猪粪及其堆肥可溶态有机质(DOM)对E2吸附的影响.结果发现,E2在土壤/沉积物表面吸附符合Freundlich等温吸附方程(R2〉0.76),E2在河流沉积物、潮土、黑土皆表现为非线性,其中黑土吸附的非线性最强(n=0.74);吸附系数Kf介于26.2~57.5,并与有机质含量呈显著正相关(P〈0.05).猪粪及其堆肥DOM显著抑制E2在土壤/沉积物表面的吸附,其中堆肥DOM的影响尤为显著.研究认为,有机质是土壤/沉积物中吸附E2的主要组分,共存猪粪DOM在较低浓度下可提高E2迁移性,增加E2向地表和地下水的迁移风险.
Natural steroid estrogens such as 17β-estradiol(E2) with low concentrations(ng·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(R20.76).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(P0.05) with Kf 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.