Priority PAHs in a Freshwater Port Along the Middle and Lower Reaches of the Yangtze River, China: Seasonal Dynamics, Sources, Ecological Risks, and Control Strategies

The seasonal dynamics, sources, and ecological risks of polycyclic aromatic hydrocarbons (PAHs) in inland freshwater ports remain largely limited, despite extensive research on coastal port PAH pollution. Here, we investigated sixteen U.S. EPA priority PAHs in surface waters of Jiujiang Port, a major inland hub along the Yangtze River, China. Total PAH concentrations ranged from 21.8 to 121.0 ng·L−1 (mean: 65.0 ng L−1), which represents relatively low levels compared with coastal ports worldwide. In this study, significant seasonal variations were also observed, with higher concentrations during the dry season than the wet season. Diagnostic ratios and multivariate analyses indicated petroleum combustion as the dominant source, while PAH levels showed positive correlations with turbidity and CODMn, underscoring the role of suspended particulates and organic load. Ecological risk assessment revealed low to moderate risks, with elevated risks in the dry season. These findings provide novel insights into PAH pollution in inland port systems and offer a scientific basis for pollution control and ecological management under the Yangtze River Protection framework.