Mali Matilda, Malcangio Daniela, Dell' Anna Maria Michela, Damiani Leonardo, Mastrorilli Piero
DICATECh, Politecnico di Bari, via Orabona, 4 I-70125 Bari, Italy.
Heliyon. 2018 Jan 2;4(1):e00494. doi: 10.1016/j.heliyon.2017.e00494. eCollection 2018 Jan.
The environmental quality of Torre a Mare port (Italy) was assessed evaluating on one side, the chemical concentration of nine metals and metalloids within bottom sediments and on the other one, by exploring the impact of hydrodynamic conditions in contaminant's transport within the most polluted basins. The investigated port was selected as case study because it resulted much more polluted than it was expected based on the touristic port activities and related stressors loading on it. In order to determine the origin and fate of contaminants in the port basin, 2D numerical simulations were carried out by MIKE21 software. The hydrodynamic module (HD) based on a rectangular grid was initially used to characterize the flow field into two domains that cover the inner and offshore harbor area. Then, advection-dispersion (AD) and water quality (WQ) modules were coupled in order to simulate the simultaneous processes of transport and dispersion of hypothetical pollutant sources. The dissolved/suspended sediment particulates (DSS) were selected as contaminant tracers. The comparative analysis between simulation responses and the real metal contaminant distribution showed high agreement, suggesting that contaminants mainly come from outside port and tend to accumulate in the inner basin. In fact, hydrodynamic circulations cause inflowing streams toward the harbor entrance and the particular port morphology hampers the exit of fine sediments from the inner basin, enhancing thus the accumulation of sediment-associated contaminants within the port area. The study confirms that the quality of touristic port areas strongly depends on both pollution sources located within and outside the port domain and it is controlled mainly by the hydrodynamic-driven processes.
对意大利托雷阿马尔港的环境质量进行了评估，一方面评估了底部沉积物中9种金属和类金属的化学浓度，另一方面通过研究水动力条件对污染最严重水域内污染物迁移的影响来进行评估。选择该研究港口作为案例研究，是因为基于旅游港口活动及其相关压力源负荷，其污染程度比预期严重得多。为了确定港口水域污染物的来源和归宿，使用MIKE21软件进行了二维数值模拟。基于矩形网格的水动力模块（HD）最初用于描述覆盖内港和外港区域的两个区域的流场。然后，将平流扩散（AD）模块和水质（WQ）模块耦合，以模拟假设污染物源的迁移和扩散同步过程。选择溶解/悬浮沉积物颗粒（DSS）作为污染物示踪剂。模拟结果与实际金属污染物分布的对比分析显示出高度一致性，表明污染物主要来自港口外部，并且倾向于在内港积聚。实际上，水动力环流导致水流向港口入口，而港口特殊的形态阻碍了细颗粒沉积物从内港流出，从而加剧了港口区域内与沉积物相关的污染物的积累。该研究证实，旅游港口区域的环境质量在很大程度上取决于港口区域内外的污染源，并且主要受水动力驱动过程的控制。
