Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology , Jinan University , Guangzhou 510632 , China.
Guangzhou Institute of Geochemistry , Chinese Academy of Sciences , Guangzhou 510640 , China.
J Agric Food Chem. 2018 Nov 7;66(44):11569-11579. doi: 10.1021/acs.jafc.8b03492. Epub 2018 Oct 26.
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 K values.
评估了在环境相关浓度下，一种农业土壤的不同粒径分数对全氟辛酸（PFOA）的吸附情况，PFOA 是一种有毒且持久的有机污染物。所有颗粒都通过薄膜扩散和颗粒内扩散来吸附 PFOA，后者是限速步骤。PFOA 的等温线数据符合线性模型。有机质（OM）、阳离子交换容量、孔体积和 Brunauer-Emmett-Teller 表面积在 PFOA 的吸附中起着关键作用。吸附能力的顺序为腐殖酸＞粘土（0.15-4.4mm）＞细粉砂（1.9-39.8mm）＞粗粉砂（17.3-79.4mm）＞细砂（45.7-316.2mm）＞粗砂（120-724.4mm），与它们对总 PFOA 吸附的贡献相反，这是由于它们在原始土壤中的重量百分比的影响。OM 含量百分比是控制各部分对总 PFOA 吸附贡献的主要因素，这表明疏水力对吸附的影响。由于低 log K 值，PFOA 在土壤-作物系统中应该具有很高的流动性和生物利用度。
