Institute for Water Quality and Resource Management- TU Wien; Karlsplatz 13/226-1, 1040, Vienna, Austria.
Institute for Water Quality and Resource Management- TU Wien; Karlsplatz 13/226-1, 1040, Vienna, Austria.
J Environ Manage. 2022 Oct 15;320:115871. doi: 10.1016/j.jenvman.2022.115871. Epub 2022 Aug 11.
In this study, we i) assessed the occurrence of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in sediments, pore water, and bulk water from three different areas in Lake Neusiedl, Austria, and ii) investigated mechanisms regulating adsorption and remobilization of these substances under different conditions via multiple lab-scale experiments. The adsorption capacity was mainly influenced by sediments' organic matter content, oxide composition, and pre-loading. Results suggest that a further increase of PFAS-concentrations in the open lake can be partly buffered by sediment transport to the littoral zone and adsorption to sediments in the extended reed belt. But, under current conditions, the conducted experiments revealed a real risk for mobilization of PFOS and PFOA from reed belt sediments that may lead to their transport back into the lake. The amount of desorbed PFAS is primarily dependent on water/sediment- or pore water/water-ratios and the concentration gradient. In contrast, water matrix characteristics and oxygen levels played a minor role in partitioning. The highest risk for remobilizing PFOS and PFOA was observed in experiments with sediments taken near the only major tributary to the lake (river Wulka), which had the highest pre-loading. The following management advice for water transport between high and low polluted areas can be derived based on the results. First, to reduce emissions into Lake waters from polluted tributaries like the Wulka river, we recommend diffuse pathways through the reed belt in the lake's littoral to reduce pollutant transport into the Lake and avoid high local sediment loadings. Second, water exchange with dried-up areas with probable higher loadings should be carefully handled and monitored to avoid critical back transport in the open lake. And third, general work in the reed belt or generally in the reed should be accompanied by monitoring to prevent uncontrolled remobilization in the future.
在这项研究中，我们：i）评估了奥地利诺伊施塔特湖（Neusiedl）三个不同区域的沉积物、孔隙水和主体水中全氟辛烷磺酸（PFOS）和全氟辛酸（PFOA）的存在情况；ii）通过多项实验室规模的实验，研究了在不同条件下调节这些物质吸附和再移动的机制。吸附能力主要受沉积物有机质含量、氧化物组成和预加载的影响。结果表明，由于湖滨带的沉积物运输和在扩展的芦苇带中吸附作用，开阔湖中的 PFAS 浓度进一步增加可以部分得到缓冲。但是，根据目前的情况，进行的实验表明，芦苇带沉积物中 PFOS 和 PFOA 的再移动存在实际风险，这可能导致它们再次进入湖中。解吸的 PFAS 量主要取决于水/沉积物或孔隙水/水的比值和浓度梯度。相比之下，水基质特性和氧水平对分配的影响较小。在靠近湖泊唯一主要支流（Wulka 河）附近采集的沉积物的实验中，观察到 PFOS 和 PFOA 再移动的风险最高，这些沉积物的预加载量最高。基于研究结果，可得出以下关于高低污染区之间水输送的管理建议：首先，为了减少像 Wulka 河这样的污染支流对湖水的排放，我们建议通过湖岸带的芦苇带采用漫流途径，以减少污染物向湖中输送，并避免沉积物局部负荷过高。其次，应谨慎处理和监测与干涸地区的水交换，以避免开阔湖中出现临界反向运输。第三，一般在芦苇带或一般在芦苇中进行的工作应伴有监测，以防止未来不受控制的再移动。
