Department of Environmental Science and Analytical Chemistry (ACES), Stockholm University, Sweden.
Universiteit van Amsterdam, Institute for Biodiversity and Ecosystem Dynamics, Science Park 904, 1098XH Amsterdam, the Netherlands.
Chemosphere. 2019 May;223:180-187. doi: 10.1016/j.chemosphere.2019.02.012. Epub 2019 Feb 5.
Perfluoroalkyl acids (PFAAs) are environmental contaminants of concern in both food and drinking water. PFAA fate in agricultural soil is an important determinant of PFAA contamination of groundwater and crops. The fate of C4-C14 perfluorinated carboxylic acids (PFCAs) and two perfluorinated sulfonic acids (PFSAs) in an agricultural soil was studied in a field lysimeter experiment. Soil was spiked with PFAAs at four different levels and crops were planted. PFAA concentrations in soil were measured at the beginning and end of the growing season. Lysimeter drainage water was collected and analysed. The concentrations of all PFAAs decreased in the surface soil during the growing season, with the decrease being negatively correlated with the number of fluorinated carbons in the PFAA molecule. PFAA transfer to the drainage water was also negatively correlated with the number of fluorinated carbons. For the C11-C14 PFCAs most of the decrease in soil concentration was attributed to the formation of non-extractable residues. For the remaining PFAAs leaching was the dominant removal process. Leaching was concentration dependent, with more rapid removal from the soils spiked with higher PFAA levels. Model simulations based on measured K values under-predicted removal by leaching. This was attributed to mixture effects that reduced PFAA sorption to soil.
全氟烷基酸（PFAAs）是食品和饮用水中受到关注的环境污染物。PFAAs 在农业土壤中的归宿是决定地下水和农作物中 PFAAs 污染的一个重要因素。在一个田间淋溶实验中研究了 C4-C14 全氟羧酸（PFCAs）和两种全氟磺酸（PFSAs）在农业土壤中的归宿。土壤中以四个不同水平添加了 PFAAs 并种植了作物。在生长季开始和结束时测量土壤中 PFAA 的浓度。收集并分析淋溶排水。在生长季节，所有 PFAAs 在表层土壤中的浓度均下降，下降幅度与 PFAA 分子中的氟化碳原子数呈负相关。PFAA 向排水中的转移也与氟化碳原子数呈负相关。对于 C11-C14 PFCAs，土壤浓度的大部分下降归因于不可提取残留物的形成。对于其余的 PFAAs，淋溶是主要的去除过程。淋溶与浓度有关，来自添加较高 PFAAs 水平土壤的去除更快。基于测量的 K 值进行的模型模拟低估了淋溶的去除。这归因于降低了 PFAA 对土壤吸附的混合效应。
