Xingchun Jiao, Wei Zhao, Jing Pan, Guohui Lu, Dian Chen, Zhaohe Zhang, Yiran Zhao
National Research Center for Geoanalysis, Chinese Academy of Geological Sciences, China.
Beijing Institute of Geological Environment Monitoring, China.
Sci Total Environ. 2023 Nov 25;901:165904. doi: 10.1016/j.scitotenv.2023.165904. Epub 2023 Jul 30.
With the growing development of modern agriculture and industry, groundwater is facing more and more complex contaminants. One such contaminant is per- and polyfluoroalkyl substances (PFASs), which pose a potential risk to human health, particularly for those who rely on groundwater as their primary source of drinking water. In this study, we conducted a comprehensive investigation on the occurrence, spatial distribution, and source apportionment of PFASs in shallow (<60 m) and deep (>80 m) groundwater samples from a reclaimed water irrigation area in Beijing's suburbs. Our results showed that the average total PFAS concentration (∑10PFAS) for all samples was 10.55 ± 7.77 ng/L, ranging from 1.05 to 34.28 ng/L. The dominant congeners were PFBA, PFOA, and PFBS. No significant linear relationship was observed between PFAS concentrations and the well depth. However, the averaged ΣPFASs in groundwater were highest in the uppermost layer and declined sharply to a few ng/L in the deep aquifer below 80 m. PFASs showed elevated concentration in shallow aquifers in 9 out of 11 paired wells, indicating an overall descending trend of PFASs with increasing aquifer depth. The spatial distribution of PFASs was highly heterogeneous and showed different patterns in shallow and deep groundwater, which may be related to the complicated attenuation behavior of PFAS compounds when they transport and diffuse through overlapping aquifer layers. The influence of the landfill on groundwater PFASs was most pronounced within a 5 km radius. Source apportionment results indicated that reclaimed water irrigation is the main non-point source of PFASs in shallow groundwater. In contrast, deep groundwater is primarily subject to point sources and lateral recharge flow. This investigation of PFASs in shallow and deep wells provides a foundation for further exploration of PFASs transportation and risk prevention in regions where groundwater is a major water resource for domestic and industrial development.
随着现代工农业的不断发展，地下水正面临着越来越复杂的污染物。全氟和多氟烷基物质（PFASs）就是其中一种污染物，它对人类健康构成潜在风险，特别是对于那些将地下水作为主要饮用水源的人群。在本研究中，我们对北京郊区一个再生水灌溉区浅（<60米）层和深（>80米）层地下水样本中PFASs的存在情况、空间分布和源解析进行了全面调查。我们的结果表明，所有样本的全氟辛烷磺酸总浓度（∑10PFAS）平均为10.55±7.77纳克/升，范围为1.05至34.28纳克/升。主要同系物为全氟丁酸（PFBA）、全氟辛酸（PFOA）和全氟丁烷磺酸（PFBS）。未观察到PFASs浓度与井深之间存在显著的线性关系。然而，地下水中的平均∑PFASs在最上层最高，在80米以下的深层含水层中急剧下降至几纳克/升。在11对井中的9对浅含水层中，PFASs浓度有所升高，表明随着含水层深度增加，PFASs总体呈下降趋势。PFASs的空间分布高度不均匀，在浅层和深层地下水中呈现出不同的模式，这可能与PFAS化合物在通过重叠含水层运移和扩散时复杂的衰减行为有关。垃圾填埋场对地下水PFASs的影响在半径5公里范围内最为明显。源解析结果表明，再生水灌溉是浅层地下水中PFASs的主要非点源。相比之下，深层地下水主要受点源和侧向补给水流的影响。对浅层和深层水井中PFASs的这项调查为进一步探索地下水是家庭和工业发展主要水资源的地区中PFASs的运移和风险预防奠定了基础。
