| 炔雌醇和壬基酚在土壤中的吸附-解吸特征 |
| 摘要点击 3276 全文点击 1176 投稿时间：2012-01-10 修订日期：2012-03-16 |
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| 中文关键词 内分泌干扰物 炔雌醇 壬基酚 土壤 吸附 解吸附 |
| 英文关键词 endocrine disrupting chemicals 17α-ethinyl estradiol(EE2) 4-n-nonylphenol(NP) soil sorption desorption |
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| 中文摘要 |
| 通过吸附动力学研究和批量平衡试验, 以炔雌醇(EE2)和壬基酚(NP)为代表,考察内分泌干扰物在3种不同性质的天然土壤中的吸附-解吸特征. 结果表明,双室一级动力学模型比单室一级动力学模型更适合描述EE2、NP在土壤中的动态吸附过程. 快吸附过程在吸附初期占据主导地位,之后慢吸附室的相对贡献逐渐增大,直至达到吸附平衡. 土壤对NP的吸附速率是EE2的2.0~4.7倍. Freundlich模型和DA模型均能较好地拟合EE2与NP的吸附等温线,但DA模型拟合效果更佳. 饱和吸附容量与土壤有机质含量呈显著正相关,EE2的饱和吸附容量(0.85~7.67 μg·g-1)明显低于NP (10.47~110.15 μg·g-1). 吸附自由能计算表明,土壤对EE2和NP的吸附以物理作用为主. 此外,3种受试土壤对EE2和NP的解吸附均存在滞后现象,需要预防其潜在的环境风险,其中有机质含量最高、比表面积最大的土样滞后性最明显. |
| 英文摘要 |
| The sorption kinetics and sorption/desorption isotherms of two endocrine disrupting chemicals(EDCs) including 17α-ethinyl estradiol(EE2) and 4-n-nonylphenol(NP) on three natural soils with different physicochemical properties were investigated. Results showed that two-compartment first-order model performed better than one-compartment first-order model in description of EDCs' kinetic sorption. The fast sorption compartment was dominant in the initial stage, and then contribution from slow sorption compartment increased gradually with time until equilibrium. The adsorption rate of EE2 was 2.0-4.7 times as that of NP. For adsorption isotherms, both Freundlich and Dubinin-Ashtakhov(DA) models provided good fit, though DA model was more appropriate. The saturated sorption capacity(Q0) was in a positive correlation to the content of soil organic matter, and higher Q0 was found for NP(10.47-110.15 μg·g-1) than EE2(0.85-7.67 μg·g-1). The calculated free energy of sorption indicated that physical process dominated sorption of EE2 and NP in soil. The desorption hysteresis occurred in sorption/desorption experiments of EE2 and NP, especially in soils with the high organic matter fraction and large specific surface, indicating EDCs' potential environmental risk in soil. |
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