藻类暴发对巢湖多环芳烃多介质归趋与迁移影响的模拟研究

Eutrophication-driven algal blooms and persistent organic pollutants (POPs) are two of the main environmental problems in fresh-water lakes around the globe. Biogeochemical cycles of POPs in lakes are affected by algal bloom, for which a quantitative and systematic evaluation by modeling are highly expected. However, modeling study on this issue are scarce. In the present research, a typical eutrophic lake - Lake Chaohu - is considered as the case study, while polycyclic aromatic hydrocarbon (PAHs) are selected as the target pollutants. An integrated lake ecosystem - food web accumulation - multimedia fugacity model for Lake Chaohu will be developed, which will be combined with causality analysis on the sediment records from field sampling. Effects of algal blooms on the multimedia fate and interface transfer of PAHs in Lake Chaohu will be investigated systematically, within different temporary scales including seasonal variations and long-term annual dynamics. In addition, changes in the fate and transfer of PAHs in Lake Chaohu in the context of future climate change, different lake trophic status and PAHs emission intensity will be predicted by the model. The outputs from this study will be of important implications for deeper understanding towards the effects and mechanisms of algal blooms on the PAHs pollution in eutrophic lakes, and will also provide scientific basis for both contamination control and risk management of PAHs in lakes.

富营养化导致的藻类暴发和持久性有机污染物（POPs）污染是当今全球湖泊面临的两大环境问题。藻类暴发会影响湖泊POPs生物地球化学循环过程，需要利用模型进行定量的和系统的评估，而该方面研究鲜有报道。本研究拟以典型富营养化湖泊—巢湖—为对象，以多环芳烃（PAHs）为目标污染物，通过构建湖泊生态-食物网累积-多介质逸度的耦合模型，并将其与湖泊沉积记录的因果关系分析相结合，系统分析季节变化和年际变化尺度下，藻类暴发对PAHs在巢湖生态系统中多介质归趋和跨界面迁移的影响，预测未来气候变化、不同富营养化水平和不同PAHs排放强度的情景下，巢湖PAHs多介质归趋和跨界面迁移的变化趋势。其研究成果，不仅对于深入认识富营养化湖泊藻类暴发对PAHs污染过程的影响及其作用机制具有重要理论意义，而且可为湖泊PAHs污染控制和风险管理提供科学依据。

富营养化导致的藻类暴发和持久性有机污染物（POPs）污染是当今全球湖泊面临的两大环境问题。藻类暴发会影响湖泊POPs生物地球化学循环过程，其影响程度和机理需要利用数学模型进行定量和系统的评估，而该方面研究鲜有报道。本项目研究取得了如下主要成果：1）收集了巢湖流域基础资料（包括社会经济、自然环境等）；2）采集并分析了巢湖东、西湖区柱状沉积物样品中PAHs残留水平和TOC、碳同位素、正构烷烃等地球化学指标，分析了藻类暴发与沉积物中PAHs残留水平之间的关系；3）构建了包括湖泊生态系统模型、食物网累积模型和多介质逸度模型三个模块的耦合模型，实现了对巢湖生态系统中藻类暴发的生态动力学过程、PAHs在巢湖主要环境非生物介质中的归趋和迁移过程和PAHs在巢湖食物网中的累积过程的系统模拟；4）阐明了藻类暴发对巢湖PAHs多介质归趋和迁移的显著影响；5）开发了农药多介质逸度模型软件（EUTOX）并获得软件著作权。本项目研究成果，不仅对于深入认识富营养化湖泊藻类暴发对PAHs污染过程的影响及其作用机制具有重要理论意义，而且可为湖泊PAHs和其他污染物的控制和风险管理提供科学依据。