湖泊水体有机污染问题严重而紧迫，其中潜流带的作用不可忽略。湖泊潜流带因湖水与地下水交互作用带来氧化还原条件波动，从而影响有机污染物的生物转化过程，对减少或消除污染物通量至关重要。本项目拟选取多溴联苯醚（PBDEs）作为目标污染物，以长江中下游江汉平原两个典型湖泊为研究区，结合野外调查与室内动态模拟实验，在揭示湖泊潜流带物理结构及其氧化还原分带特征基础上，探明不同氧化还原分带特征对典型脱卤呼吸菌群丰度、多样性分布及其还原脱溴潜力的影响规律；明确不同潜流模式下PBDEs的降解速率及程度，建立不同潜流模式下沉积物-水相界面PBDEs削减通量的量化模型；依托宏基因组和宏转录组分析，深入揭示氧化还原波动对PBDEs自然衰减过程中关键脱卤菌群组成及代谢功能的影响与效应。为丰富和发展湖泊潜流带卤代有机污染物衰减过程中微生物群落动态演替理论、评估自然衰减效果和污染生态风险提供科学依据和技术支持。

Refractory organic pollutants contamination in lake systems is serious and urgent, and the role of hypolentic zones cannot be ignored. Due to the interaction between lake water and groundwater, the redox conditions fluctuate in hypolentic zones, which affects the biotransformation processes of organic pollutants and thus is critical to reduce or eliminate contaminant fluxes to groundwater. In this research project, polybrominated diphenyl ethers (PBDEs) are selected as the target pollutants, and two typical lakes in the Jianghan Plain of the middle and lower reaches of the Yangtze River are chosen as the study areas. Based on field study and lab dynamic simulation experiments, it aims to firstly identify and characterize the physical structure and redox zoning of the hypolentic zones; to reveal the influencing mechanisms of the redox zoning condition on the abundance and diversity of typical organohalide respiring bacteria (OHRB) and their reductive debromination potential; to propose a quantitative model of PBDEs flux reduction at sediment-water interface by determining the degradation rate and degree of PBDEs under different subsurface flow modes, and to further discover the effect and impact of redox alternation on typical OHRB involved in PBDE degradation and their metabolic capabilities by metagenomic and metatranscriptomic analyses. The findings will help to provide the scientific basis and technical support for the enrichment and development of the dynamic succession theory of microbial community during natural attenuation processes of halogenated organic pollutants, and for the evaluation of natural attenuation efficiency and pollution ecological risk in lake hypolentic zones.