沼灌区雌激素在紫色土中的吸附行为研究. (Chinese)

At present, anaerobically fermented manures in most livestock farms have been, in some extent, reused to cropland, thereby steroidal estrogens (SEs) in methane that contained in fermented manures can accumulate in the cropland soils, exacerbating the risk of SEs contamination in the environment. In this paper, the SEs adsorption characteristics onto purple soils in southwest China were investigated, and the adsorption kinetic processes and adsorption thermodynamics of free state estrogens (FEs) including estrone, 17α-estradiol and 17β-estradiol, as well as bound estrogens (CEs) including estrone-3-sulfate, were explored using the batch equilibrium method; in addition, the analysis of the adsorption mechanism. It was found that four kinds of estrogens, in terms of adsorption, were divided into two phases: rapid adsorption and slow equilibrium in purple soil, and the magnitude of the amount of SEs adsorption onto the soil could be expressed as the follows: cestrone>17αestradiol≈17 β- estradiol>>estrone-3-sulfate; the kinetic processes conformed to the quasi-secondary kinetic equation (R2 > 0.999), and the Langmuir model could well describe the adsorption behavior of FEs on to purple soil, while the adsorption of CEs conformed to the Freundlich model even better. In addition, the characterization by FTIR indicated that the intensity of the absorption peaks of FEs were all enhanced after adsorption, while the intensity of the absorption peaks of CEs was weakened, and the free hydroxyl group became a potential bonding site with the hydrogen bonding being involved in the adsorption process. The adsorption process of the four estrogens in soil was a spontaneous exothermic reaction, and higher temperatures inhibited the adsorption, reducing the soil adsorption capacity. The results of the experimental study is expected to be helpful to the prediction and analysis of the environmental fate and ecological risk of SEs in the soil environment, besides providing a basis for scientific reuse of methane. [ABSTRACT FROM AUTHOR]

目前大多数养殖场厌氧发酵产生的粪污均有一定程度的回用于农田, 沼液中的类固醇雌激素 (SEs) 会在土壤中累积, 加剧 环境中SEs污染风险。该文研究了西南地区紫色土对SEs的吸附特性, 采用批平衡法探究了自由态雌激素 (FEs): 雌酮, 17α-雌二醇, 17β-雌二醇和结合态雌激素 (CEs): 雌酮-3-硫酸盐的吸附动力学过程和吸附热力学规律, 并对吸附机理进行分析。结果表明4种雌激 素在紫色土中分为快速吸附和缓慢平衡2个阶段, 土壤对SEs的吸附量大小为雌酮>17α-雌二醇≈17β-雌二醇>>雌酮-3-硫酸盐。动力 学过程符合准二级动力学方程 (R² >0.999), Langmuir模型能够较好地描述FEs在紫色土中的吸附行为, CEs的吸附则更符合Freundlich 模型。通过FTIR表征, 吸附后FEs吸收峰强度均有所增强, 而CEs吸收峰强度减弱, 游离羟基基团成为潜在的结合点位, 氢键参与了吸 附过程。4种雌激素在土壤中吸附过程为自发放热反应, 较高的温度抑制其吸附, 降低土壤吸附容量。研究结果有助于预测和分析以土 壤环境中SEs的环境归趋和生态风险, 为科学地回用沼液提供依据. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)