Zhang Dongrui, Yu Xiaoxia, Ren Hongwei, Sun Xueshi, Duan Lian, Lin Tian, Guo Zhigang
Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Fudan University, Shanghai 200433, China; State Environmental Protection Key Laboratory of Land and Sea Ecological Governance and Systematic Regulation, Shandong Academy for Environmental Planning, Jinan 250101, China; Institute of Eco-Chongming (IEC), Shanghai 202162, China.
State Environmental Protection Key Laboratory of Land and Sea Ecological Governance and Systematic Regulation, Shandong Academy for Environmental Planning, Jinan 250101, China.
Mar Pollut Bull. 2025 Apr;213:117676. doi: 10.1016/j.marpolbul.2025.117676. Epub 2025 Feb 17.
Marine sediments are an important sink for global polycyclic aromatic hydrocarbons (PAHs); however, the influence of seasonal hydrodynamic conditions on sedimentary PAHs along the continuum of large river-estuary-shelf systems remains unclear. Surface sediment samples collected from the Yangtze River Estuary (YRE) in winter (March 2015) and summer (July 2019) were analyzed for the sixteen USEPA priority PAHs (16 PAHs). The total concentration of 16 PAHs was substantially lower in winter (13.3-318.9 ng g, mean 74.2 ± 75.6 ng g) compared to summer (71.9-421.0 ng g, mean 168.9 ± 86.0 ng g). PAHs concentrations displayed a "low-high-low" trend along the river-estuary-shelf system, indicating a similar spatial distribution pattern between two seasons. Source analysis demonstrated that PAHs in the YRE were derived from a mixture of petrogenic and pyrolytic sources, with no distinct seasonal difference. Under the influence of East Asian Monsoon, riverine input PAHs were stored in nearshore estuary during summer, while winter sediment resuspension led to their outward transport. A lower reduction of PAHs in the estuarine mixing zone than that in the river channel and the continental shelf was observed in winter due to the sediment resuspension. This supports the notion that winter East Asian Monsoon-driven sediment resuspension significantly influences the behavior of sedimentary PAHs in the YRE.
海洋沉积物是全球多环芳烃（PAHs）的重要汇；然而，季节性水动力条件对大河-河口-陆架系统连续区域内沉积多环芳烃的影响仍不清楚。对2015年3月冬季和2019年7月夏季从长江河口（YRE）采集的表层沉积物样本进行了16种美国环境保护局优先监测的多环芳烃（16种PAHs）分析。与夏季（71.9 - 421.0 ng g，均值168.9 ± 86.0 ng g）相比，16种PAHs的总浓度在冬季（13.3 - 318.9 ng g，均值74.2 ± 75.6 ng g）显著较低。多环芳烃浓度沿河口-陆架系统呈现“低-高-低”趋势，表明两个季节的空间分布模式相似。源解析表明，长江河口的多环芳烃来自成岩源和热解源的混合，且无明显季节差异。在东亚季风影响下，河流输入的多环芳烃在夏季储存在近岸河口，而冬季沉积物再悬浮导致它们向外输送。由于冬季沉积物再悬浮，河口混合区多环芳烃的降解程度低于河道和大陆架。这支持了冬季东亚季风驱动的沉积物再悬浮显著影响长江河口沉积多环芳烃行为的观点。
