全球气候变化背景下水环境中典型有机污染物的沉积记录和归宿

The biogeochemical processese such as depositional history, interface partitioning, degradation, and fate of typical persistent organic contaminants (POPs) (PAHs and PBDEs), and their coupling relationships with global climate change in the aquatic environment of the Pearl River Delta will be investigated. The study is a frontier basic project relating to the change of regional environmental quality, water pollution control, and water environmental quality protection. Through field sampling and laboratory analysis and simulation, the depositonal regularity and fluxes, interface exchange among water-sediment-biota, and seasonal variation of the major POPs in the aquatic environment of the Pearl River Delta will be targeted. The speciation of POPs, and isolation of amorphous and condensed organic carbons and their radiocarbon age in the sediments will also be investigated. The interaction mechanism between sediment/ suspended particles and POPs and its relationship with the organic carbon forms will be illustrated. The in-situ partitioning, bioavailability, biodegradation, and fate of POPs in sediments will be expounded. The project has theoretical and practical importance in determining transport, persistence, and fate of POPs in water environment of the Pearl River Delta, and in stipulating the management and control strategy of POPs in the Pearl River basin.

拟进行的珠江流域不同水环境中典型有机污染物（多环芳烃和多溴联苯醚）的沉降历史、水-颗粒物-藻类分布、降解等生物地球化学过程以及与全球环境变化的耦合关系研究，是一项与区域环境质量变化、水环境污染控制和水环境质量保护相结合的前沿性研究课题。通过野外观察和采样、室内分析和模拟，揭示典型有机污染物在珠江流域水环境中的沉积规律和沉积物通量、水-颗粒物-沉积物-生物界面交换、降解动力学和机制，探讨沉积物中典型有机污染物的赋存形态、不同形态有机碳的分离提取方法及C-14 年龄，明确这些有机污染物在沉积物和悬浮颗粒物的结合机理及其与不同形态有机碳含量和组成的关系，阐述它们的原位分配特征、生物有效性和降解机制，探索区域环境污染和水环境质量的演变规律。该项目在确定典型有机污染物在珠江三角洲水环境中的迁移、残留和归宿，制定珠江流域内典型有机污染物的调控措施等方面有重要的理论和现实意义。

应用核磁共振光谱、多种有机分子标记物（中性糖、类脂等）、Pb-210和Cs-137同位素等分析技术，表征了水生有机质的化学成分、结构和形态，研究了水环境中主要毒害有机污染物（多环芳烃、多溴二苯醚）的沉积历史、沉积、沉积物记录和归宿等过程。通过系统地研究水环境中有机污染物的含量分布、季节性变异，以及沉积柱状样品的历史分布及其和全球变暖的关系，探讨了区域环境污染和水环境质量的变化规律，以及受全球变化的影响。运用有机地球化学的研究方法和技术，深入地揭示了天然有机质组成和性质的非均一性和复杂性及其来源的多样性。研究水环境中天然有机质成分、结构在早期成岩作用、裂解作用下的变化规律及其模型；进一步阐明毒害有机化合物的微观吸附机制、生物有效性和环境风险。本项研究的开展对于确定区域水环境中典型有机化合物的演变趋势及其预测，以及研发有效的环境修复技术和修复终点等方面有重要的理论和现实意义。