Mechanism and Implication of the Sorption of Perfluorooctanoic Acid by Varying Soil Size Fractions.
Mechanism and Implication of the Sorption of Perfluorooctanoic Acid by Varying Soil Size Fractions.
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DOI：
10.1021/acs.jafc.8b03492
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发表时间：
2018-09
影响因子：
6.1
通讯作者：
L. Xiang;Tao Xiao;Peng-fei Yu;Hai-Ming Zhao;C. Mo;Yan-Wen Li;Hui Li;Q. Cai;Dong-mei Zhou-
中科院分区：
文献类型：
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作者：
L. Xiang;Tao Xiao;Peng-fei Yu;Hai-Ming Zhao;C. Mo;Yan-Wen Li;Hui Li;Q. Cai;Dong-mei Zhou-
研究了不同粒径的农业土壤在环境相关浓度下对有毒持久性有机污染物全氟辛酸（PFOA）的吸附。PFOA吸附到所有馏分涉及膜扩散和颗粒内扩散与后者的限速步骤。PFOA等温线数据符合线性模型。有机质（OM），阳离子交换容量，孔隙体积，和Brunauer-Emmett-Teller面积在PFOA吸附中起着关键作用。吸附容量大小顺序为腐殖酸>粘土（0.15-4.4 mm）>细粉土（1.9-39.8 mm）>粗粉土（17.3-79.4 mm）>细砂（45.7-316.2 mm）>粗砂（120-724.4 mm），这与它们对PFOA总吸附量的贡献相反，这是由于它们在原始土壤中的重量百分比的影响。OM含量百分比是控制全氟辛酸总吸附分数贡献的主导因素，表明疏水力对吸附的影响。全氟辛酸在土壤-作物系统中应具有高度移动的和生物可利用性，因为其对数值较低。
Sorption of perfluorooctanoic acid (PFOA), a toxic and persistent organic pollutant, by various size fractions of an agricultural soil at environmentally relevant concentrations was evaluated. PFOA sorption to all fractions involved both film diffusion and intraparticle diffusion with the rate-limiting step by the latter. PFOA isotherm data fitted a linear model. Organic matter (OM), cation exchange capacity, pore volume, and the Brunauer-Emmett-Teller area played key roles in PFOA sorption. The sorption capacity followed the order of humic acid > clay (0.15-4.4 mm) > fine silt (1.9-39.8 mm) > coarse silt (17.3-79.4 mm) > fine sand (45.7-316.2 mm) > coarse sand (120-724.4 mm), opposite to their contributions to overall PFOA sorption due to the influence of their percentage weight in the original soil. Percentage OM content was the dominant factor controlling the fraction contributions to overall PFOA sorption, demonstrating influence of the hydrophobic force on sorption. PFOA should be highly mobile and bioavailable in soil-crop systems due to the low log Koc values.