Source identification and ecological risks of parent and substituted polycyclic aromatic hydrocarbons in river surface sediment-pore water systems: Effects of multiple factors

Yang Liu; Yong He; Yu Liu; HuiJuan Liu; Shu Tao; WenXin Liu

doi:10.1016/j.scitotenv.2022.159921

Source identification and ecological risks of parent and substituted polycyclic aromatic hydrocarbons in river surface sediment-pore water systems: Effects of multiple factors

Sci Total Environ. 2023 Feb 1;858(Pt 3):159921. doi: 10.1016/j.scitotenv.2022.159921. Epub 2022 Nov 4.

Authors

Yang Liu¹, Yong He², Yu Liu², HuiJuan Liu³, Shu Tao², WenXin Liu⁴

Affiliations

¹ Key Laboratory for Earth Surface and Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China; Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
² Key Laboratory for Earth Surface and Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
³ Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
⁴ Key Laboratory for Earth Surface and Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China. Electronic address: wxliu@urban.pku.edu.cn.

PMID: 36343826
DOI: 10.1016/j.scitotenv.2022.159921

Abstract

Substituted polycyclic aromatic hydrocarbons (SPAHs) have shown higher health and ecological risks than the corresponding parent PAHs (PPAHs) from laboratory studies, their variations in freshwater system, especially in surface sediment and pore water, remain inadequate understanding. In this study, we revealed the coexistence, ecological risk, and multiple factors affecting variations and sources of PPAHs and SPAHs (nitrated PAHs (NPAHs), oxygenated PAHs (OPAHs)) in the surface sediment-pore water system from a typical urban river in Northern China. The concentration ranges of Σ₂₆PPAHs, Σ₁₀NPAHs, and Σ₄OPAHs in the surface sediments were 153.0-5367.4, not detected (N.D.)-105.4, and 42.2-1177.0 ng·g^-1 dry weight, and fell within 0.6-38.8, N.D.-297.9, and N.D.-212.6 ng·mL^-1 in the pore waters. The t-distributed stochastic neighbor embedding (SNE) coupled with the partitioning around medoids (PAM) elucidated spatiotemporal the variations in PAHs, emphasizing the impacts of industrial activities and sewage discharges. Besides the geochemical and hydrochemical conditions, SPAHs were affected by the potential secondary formation, especially during the wet season. The method comparisons indicated the advantages of principal component analysis-multivariate linear regression (PCA-MLR) and n-alkanes model on source identification. PAHs mainly originated from fossil fuel combustion and vehicular exhaust. The top risk quotient (RQ) values for PAHs occurred in the urban and industrial sections. A majority of the surface sediment samples emerged with low to moderate exposure risks, while all the pore water samples showed high exposure risks. The RQs of OPAHs were significantly higher (p < 0.01) than those of PPAHs. The results suggested the secondary formation of SPAHs as an important role in ecological risks of PAHs in the urban river system.

Keywords: PAHs; Risk assessment; River; Source analysis; n-Alkanes.

MeSH terms

China
Polycyclic Aromatic Hydrocarbons*
Water

Substances

Polycyclic Aromatic Hydrocarbons
Water