太湖沉积柱中的多环芳烃及其与沉积物有机质的关系
Polycyclic aromatic hydrocarbons (PAHs) in a sediment core from Lake Taihu and their associations with sedimentary organic matter
Yong He*, Xiangyu Wang, Zhaobin Zhang
https://doi.org/10.1016/j.jes.2022.09.013
摘要
湖泊沉积柱是多环芳烃污染历史及与之相关的有机质的记录者，对于污染控制和环境管理具有重要参考价值。本研究通过一根50厘米的沉积柱重建了太湖近一个世纪以来多环芳烃和有机质沉积历史。太湖沉积柱中多环芳烃的含量范围为8.99至199.2 ng/g，随着深度的增加，多环芳烃的含量呈下降趋势。太湖多环芳烃的沉积历史可分为两个阶段，时间序列聚类分析表明突变点出现在20厘米深度处。在组成上，多环芳烃以三环多环芳烃为主（44.6% ± 9.1%，平均值±标准差），其次是四环（27.0% ± 3.3%）和五环（12.1% ± 4.0%）多环芳烃。在毒性评估方面，基于苯并[a]芘毒性当量的沉积记录可以被一个R2为0.95的指数模型很好地描述。根据模型结果，太湖多环芳烃环境背景毒性值为1.62 ng/g。此外，不同组分有机质可通过正构烷烃分子标志物表示（p < 0.01），有机质的变化也得到了很好的解释（84.6%）。通过时间序列聚类分析，在22厘米深度处识别出了有机质的突变。相关性研究表明，沉积物中的多环芳烃与人类活动和生物生成的有机质有关（p < 0.05），多数污染物方差解释度达60%。这表明多环芳烃的垂直分布受沉积物有机质的驱动。因此，为减少多环芳烃的环境影响，除了控制其排放外，生物因素等环境过程也应引起更多关注。
亮点
利用正构烷烃分子标志物研究了太湖沉积柱中不同来源有机质对多环芳烃沉积历史的影响
Abstract
Sediment core is the recorder of polycyclic aromatic hydrocarbon (PAH) pollutions and the associated sedimentary organic matter (SOM), acting as crucial supports for pollution control and environmental management. Here, the sedimentary records of PAHs and SOM in the past century in Lake Taihu, China, were reconstructed from a 50-cm sediment core. On the one hand, the presence of PAHs ranged from 8.99 to 199.2 ng/g. Vertically, PAHs declined with the depth increased, and the sedimentation history of PAHs was divided into two stages with a discontinuity at 20 cm depth. In composition, PAHs in the sediment core were dominated by three-ring PAHs (44.6% ± 9.1%, mean ± standard deviation), and were followed by four-ring (27.0% ± 3.3%), and five-ring (12.1% ± 4.0%) PAHs. In toxicity assessment, the sedimentary records of benzo[a]pyrene-based toxic equivalency were well described by an exponential model with R-square of 0.95, and the environmental background toxic value was identified as 1.62 ng/g. On the other hand, different components of SOM were successfully identified by n-alkane markers (p < 0.01) and the variations of SOM were well explained (84.6%). A discontinuity of SOM was recognized at 22 cm depth. Association study showed that the sedimentary PAHs were associated with both anthropogenic and biogenic SOM (p < 0.05) with explained variances for most individual PAHs of 60%. It indicated the vertical distributions of PAHs were driven by sedimentary SOM. Therefore, environmental processes such as biogenic factors should attract more attentions as well as PAH emissions to reduce the impacts of PAHs.
作者简介
贺勇博士于2023年在北京大学获得博士学位，现任中国科学院生态环境研究中心博士后/特别研究助理，入选2023年度博士后创新人才支持计划。主要从事新污染物的环境行为及效应研究。在Water Res., Sci. Total Environ.等国际期刊上发表研究论文24篇（第一作者/通讯作者研究论文13篇）。
原文链接
https://www.sciencedirect.com/science/article/abs/pii/S1001074222004521
引用格式
Yong He, Xiangyu Wang, Zhaobin Zhang, 2023. Polycyclic aromatic hydrocarbons (PAHs) in a sediment core from Lake Taihu and their associations with sedimentary organic matter. J. Environ. Sci. 129, 79-89.
