Kalbe Ute, Piechotta Christian, Bandow Nicole
BAM Federal Institute for Materials Research and Testing: Bundesanstalt für Materialforschung und -prüfung, 12200, Berlin, Germany.
German Environment Agency, Colditzstraße 34, 12099, Berlin, Germany.
Environ Sci Pollut Res Int. 2024 Dec;31(57):65233-65251. doi: 10.1007/s11356-024-35510-0. Epub 2024 Nov 22.
Laboratory leaching tests are tools to assess the mobility of environmental contaminants released from granular materials. Comparative leaching tests were performed using four PFAS-contaminated soils whose concentration patterns of 10 selected perfluoroalkyl and polyfluoroalkyl substances (PFAS) differed due to the two types of contamination sources. This study aimed to evaluate the equivalence of two usual laboratory-scale leaching test procedures, batch and column percolation tests, at liquid-to-solid ratios (L/S) of 2 l/kg, which is the current practice within the German assessment framework, and 10 l/kg (relevant for some EU regulations such as the landfill directive). The differences between the replicates of leaching tests investigating PFAS were smaller for column percolation tests than for batch tests, probably mainly due to the greater sample size and the better representativeness of the sample portion analyzed. It was observed that batch tests overestimate the release of shorter-chain PFAS, whereby the effect was greater with carboxylic than with sulfonic acids. Currently, the limits of detection of analyses given by the DIN standard with regard to PFCA and PFSA in soils are partly not sufficient to detect very low contents, whereas the detection of selected PFCA and PFSA in eluates is more sensitive, in accordance with the available standards. This results in limitations when calculating mass balances.
实验室浸出试验是评估颗粒材料释放的环境污染物迁移性的工具。使用四种受全氟辛烷磺酸污染的土壤进行了对比浸出试验，这四种土壤中10种选定的全氟烷基和多氟烷基物质（PFAS）的浓度模式因两种污染源类型而有所不同。本研究旨在评估两种常用的实验室规模浸出试验程序，即批量试验和柱渗透试验，在液固比（L/S）为2 l/kg（这是德国评估框架内的现行做法）和10 l/kg（与一些欧盟法规如垃圾填埋指令相关）时的等效性。研究PFAS的浸出试验复制品之间的差异，柱渗透试验比批量试验小，这可能主要是由于样本量更大以及所分析样本部分的代表性更好。据观察，批量试验高估了短链PFAS的释放，其中羧酸的影响比磺酸更大。目前，DIN标准给出的土壤中全氟羧酸（PFCA）和全氟磺酸（PFSA）分析检测限部分不足以检测极低含量，而根据现有标准，洗脱液中选定PFCA和PFSA的检测更灵敏。这在计算质量平衡时会导致局限性。
