新型污染物氯代多环芳烃在珠江河口及近岸环境中的生成机制与环境行为研究

Estuary is considered as a transition area which connects the terrestrial and marine ecosystems. Organic contaminants could enter the estuary through surface runoff, creating long-term adverse effects on the costal resources. In this study, Chlorinated polycyclic aromatic hydrocarbons (Cl-PAHs) are selected as the target compounds, whereas different typical regions of the Pearl River Estuary (PRE) are selected as the sampling and studying area, including the whole PRE, Humen rumoff, Modaomen runoff and Futian mangrove wetland. Based on the development of.analytical methods in complex environmental matrix, Parent PAHs and their chlorinated derivatives would be determined to investigate their source and spatial distributions. Moreover, the emphases of this study would be addressed on the understanding of whether PRE is the source or the sink of Cl-PAHs. Moreover, the food chain transfer and biomagnification of H-PAHs in benthonic organism of mangrove wetland would be discussed as well. Finally, the production of Cl-PAHs from parent PAHs via photocatalysis would be investigated under field observation and laboratory simulation, respectively. In order to find out the key factors, the effects of different environmental factors would be discussed. Obviously, this study would improve our in-depth understanding of the fate of Cl-PAHs in complex estuarine environment, and provide theoretical and practical basis for Cl-PAHs control and remediation in estuarine and costal environments.

河口及近岸生态环境是连接陆地生态系统以及海洋生态系统的特殊过度区域，新型污染物经河口特殊的环境过程后可随大洋环流参与全球循环，从而对海洋环境及生态系统产生影响。本项目主要是以氯代多环芳烃（Cl-PAHs）作为主要研究对象，以珠江口及近岸生态环境作为研究区域，探讨Cl-PAHs及其来源的PAHs前体在不同环境介质中（溶解性有机质、悬浮颗粒物以及沉积物）的分布特征，并且通过调查Cl-PAHs在珠江口底栖生物食物链中的传递和生物放大作用，探讨Cl-PAHs的河口环境行为。通过河口不同水动力条件以及各种环境因子的改变对Cl-PAHs分布以及形成的影响规律，结合野外与实验室模拟Cl-PAHs生成实验，阐明PAHs母体以及其他Cl-PAHs前体在河口多环境介质迁移过程中的氯代转化机理及其影响因素。解决Cl-PAHs在珠江河口近岸复杂环境中的环境行为与化学过程。

多环芳烃的衍生物已被证实有着更强毒性，且难以降解。因此这些新型机环芳烃的衍生物应得到更多的关注 。河流作为陆源物质入海的重要通道，将人类活动产生的污染物排放到海洋中，而河口作为连接流与海洋的重要过度地带，有着特殊 河口作为连接流与海洋的重要过度地带，有着特殊的水动力和沉积特征。珠江河口航运繁忙，原油泄漏、化石燃料燃烧排放问题严重。因此本项目以珠江河口作为研究区域，揭示了揭示了 100种母体多环芳烃及其两类衍生物 ：烷基多环芳烃 (Alkyl PAHs, APAHs)、卤代多环 、卤代多环芳烃 (Halogenated PAHs, HPAHs)在珠江口海水、悬浮颗粒物以及表层沉积和中 在珠江口海水、悬浮颗粒物以及表层沉积和中的污染特征，并通过模拟实验探究海水中盐度 （天然氯源及溴）对 PAHs与 HPAHs的转化关系的影响，深入阐明了河口近岸水体环境中 PAHs及其衍生物的迁移转化规律。