Key Laboratory of the Three Gorges Reservoir Region' s Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing, China; Observation and Research Station of Ecological Restoration for Chongqing Typical Mining Areas, Ministry of Natural Resources, Chongqing Institute of Geology and Mineral Resources, 401120, China.
Key Laboratory of the Three Gorges Reservoir Region' s Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing, China.
Environ Pollut. 2024 Aug 15;355:124216. doi: 10.1016/j.envpol.2024.124216. Epub 2024 May 24.
The Three Gorges Reservoir (TGR) is totally manmade, strongly influenced by anthropogenic activity, and lies on the upper reaches of Yangtze River. The periodic storage and discharge of water from the Three Gorges Dam could have altered the original air-plant/soil interactions of contaminants in TGR. Herein, paired atmospheric gas-particle, air-plant, and air-soil samples were collected to investigate the air-plant interaction and air-soil exchange of 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs). The air-plant interaction based on McLachlan's framework to our datasets suggests that PAHs were absorbed via gaseous deposition that was restricted by the plant-gas dynamic equilibrium. The equilibrium indicates a dynamic balance between the gaseous phase and plant surface in PAH absorption. The main limiting factor influencing the PAH uptake was the plant species rather than the atmospheric PAH concentration. The air-soil exchange of PAHs exhibited a net volatilization flux of 16.71 ng/m/d from the soil to the air based on annual average. There was more volatilization and less deposition in summer and more deposition and less volatilization in autumn and winter. The soil serves as a secondary source of atmospheric PAHs. As the first attempt on probing the multi-interface geochemical process of PAHs, this study highlights the influence of manual water level manipulation from the TGD and environmental factors (such as temperature, humidity, and soil properties) on the regional fate of PAHs in the TGR.
三峡水库是完全人工建造的，强烈受到人类活动的影响，位于长江上游。三峡大坝的定期蓄水和放水可能改变了三峡水库中污染物的原有空气-植物/土壤相互作用。在此，采集了成对的大气气粒、空气-植物和空气-土壤样本，以研究 16 种美国环保署优先多环芳烃（PAHs）的空气-植物相互作用和空气-土壤交换。基于 McLachlan 框架对我们数据集的空气-植物相互作用表明，PAHs 通过受植物-气体动态平衡限制的气态沉积被吸收。该平衡表明了 PAH 吸收过程中气态相和植物表面之间的动态平衡。影响 PAH 吸收的主要限制因素是植物种类，而不是大气中 PAH 的浓度。基于年平均水平，PAHs 的空气-土壤交换显示出从土壤到空气的净挥发通量为 16.71ng/m/d。夏季挥发较多，沉积较少，秋季和冬季沉积较多，挥发较少。土壤是大气 PAHs 的二次源。作为对 PAHs 多界面地球化学过程进行探测的首次尝试，本研究强调了人为操纵三峡大坝水位和环境因素（如温度、湿度和土壤特性）对三峡水库中 PAHs 区域命运的影响。
