富营养化湖泊沉积物中HOCs同分异构体分馏机理研究

Environment behaviors, fates and ecological impacts of hydrophobic organic pollutants (HOCs) are related to their physicochemical properties combining environmental processes. Similar environment behaviors and impacts would be expected for the contaminants with similar physiochemical properties, but weak differences on physicochemical properties can cause significant isomer fractionation of HOCs in environments. Previous studies conducted by applicant revealed clear isomer fractionation of organic contaminants in surface sediments of Chaohu Lake, however the mechanisms are still unknown. In order to examine the reliable on the influence of environmental processes on isomer fractionation of HOCs in bottom sediment of Chaohu Lake, an eutrophicated lake, the research objectives are to study tempo-spatial variations of selected several paired HOCs isomers in sediment, water and phytoplankton; to explore the mechanism of the isomer fractionation during kinds of environmental processes using multiple techniques. A special attention will be paid to investigate how phytoplankton as a critical environmental vector controls the isomer fractionation during the exchange between water –sediment, water – phytoplankton, and phytoplankton – sediment. Finally diffusive modes will be developed and applied to simulate the environmental behaviors between water –sediment and water- phytoplankton for exploration on the mechanism of isomer fractionation of selected HOCs in sediment of an eutrophicated lake

疏水性有机污染物（HOCs）的环境行为和生态效应与其物理化学性质及环境过程息息相关，性质相似的污染物在相同系统中行为和效应相似，但微弱的差异可导致它们同分异构体在不同过程中产生分馏。申请人前期研究发现富营养化湖泊（巢湖）沉积物中多组污染物同分异构体存在分馏，但对其产生原因尚不明确。为了探究其真正作用机制，本研究拟以巢湖为研究靶区，并选取多组HOCs同分异构体，揭示在底部沉积物、水体和藻类中分馏的时空变化规律和环境影响要素；结合多种技术研究不同过程对同分异构体分馏效应的影响，关注藻类为核心介质，如何调控HOCs在水体‒沉积物、水体‒藻类和藻类‒沉积物迁移转化过程中的分馏效应。最终通过扩散模型模拟巢湖湖区目标HOCs在水体‒沉积物及水体‒藻类间环境过程和归趋，明确导致不同污染物在富营养化湖泊沉积物中HOCs同分异构体分馏效应的关键机制。

疏水性有机污染物（HOCs）的环境行为和生态效应与其物理化学性质及环境过程息息相关，性质相似的污染物在相同系统中行为和效应相似，但微弱的差异可导致它们同分异构体在不同过程中产生分馏。本研究过程中，通过采集巢湖流域大气、水体、沉积物、生物体和藻类，并结合原位被动采样技术，研究了巢湖流域不同介质中HOCs及其同分异构体的分馏特征。结果表明：（1）大气中PAHs的分馏取决于饱和蒸气压和环境温度；（2）并通过被动采样技术研究了巢湖流域水体-沉积物界面处PAHs的交换，确定了多环芳烃在水体-沉积物交换的通量；（3）构建了巢湖流域多环芳烃和拟除虫菊酯类杀虫剂的多介质扩散，明确了其在生态系统里的迁移转化过程，基本明确了沉积物中PAHs同分异构体分馏机理。共计发表SCI论文5篇，已培养硕士研究生4名，项目总体基本完成。