微生物联合生物炭修复洞庭湖表层底泥中PBDEs及其衍生物污染的行为与机理研究

The surface sediment of Dongting Lake has become a high risk area for the exposure of recalcitrant polybrominated diphenyl ethers (PBDEs). PBDEs are characterized by bioaccumulation, environmental persistence and biological toxicity, which pose a severe threat to ecosystems and human safety. Biodegradation of PBDEs is considered as a method of low cost and non-secondary pollution. However, little research has been conducted on the removal of PBDEs in surface sediment by composited microbial materials loading on biochar. Besides, the influence mechanism to environment and biological effect towards other population in the remediation process has not been elucidated. This project intends to prepare composited microbial materials immobilized on biochar and optimize the preparation. Considering the contamination of PBDEs in the surface sediment of Dongting Lake, exogenous substances will be added for PBDEs removal by composited microbial materials. Adsorption process and degradative pathways will be analyzed to elucidate the behavior mechanism in actual reparative process. In addition, the project will explore the ecological effect in the remediation process of surface sediment by the composited microbial materials systematically. It is expected that the results of this project will provide theoretical guidance and technical support for pollution control and remediation of recalcitrant halogenated organics in the sediment.

洞庭湖表层底泥已成为难降解卤代有机物多溴联苯醚（PBDEs）及其衍生物暴露的高风险区域。PBDEs具有生物累积性、环境持久性和生物毒性，对生态系统及人体健康造成严重威胁。采用微生物法降解PBDEs是一种经济环保的处理方法，而将其与生物炭联用制成复合微生物材料处理底泥中的PBDEs污染研究尚少，且对于修复过程中PBDEs及其衍生物对环境的影响机制及其对生态系统中其它种群的生物效应仍需阐明。本项目拟采用生物炭负载高效微生物菌株，优化制备复合微生物材料，针对当前洞庭湖表层底泥中PBDEs污染状况，考察外源添加物对PBDEs降解效果的影响，分析复合微生物材料介导底泥PBDEs的吸附过程机理及降解路径，并在此基础上，系统研究复合微生物材料修复污染底泥过程中的生物效应。以期为洞庭湖表层底泥中难降解卤代有机物的污染修复提供实践参考与理论依据。

多溴联苯醚（PBDEs）作为一种新型持久性有机污染物，具有化学性质稳定、疏水亲脂性、低挥发性和易被生物富集的特点，对人体具有潜在致癌作用，并对神经、内分泌和免疫系统等有毒害作用。本项目采用生物炭负载高效微生物菌株，优化制备复合微生物材料；针对当前洞庭湖表层底泥中PBDEs污染状况，利用响应面法优化外源添加物对PBDEs的强化降解,使得PBDEs的降解率提高了20%左右；分析复合微生物材料介导底泥PBDEs降解路径及吸附过程机理，揭示实际修复过程中PBDEs的迁移转化规律；并在此基础上，利用分子对接法探究OH-PBDEs的甲状腺干扰机制，发现其甲状腺干扰效应与PBDEs的衍生物OH-PBDEs中溴原子个数、分子结构、与甲状腺转运蛋白的结合力等有密切关系。探究了复合微生物材料修复污染底泥的生物效应变化，以期为洞庭湖表层底泥中难降解卤代有机物的污染修复提供提供理论基础和实践指导。