环境微界面对湖泊内源磷释放的影响研究

为揭示湖泊内源污染的微界面环境行为及机制，从环境微界面角度出发，研究湖泊水-沉积物界面三相结构模式中磷的界面反应过程。利用微电极系统获取了微界面溶氧浓度剖面，结合Profile模型进行了分析计算。结果发现，玄武湖湖心区沉积柱含氧层厚度达5mm，而湖口区则不到3mm，湖心区微界面上氧气消耗主要以自由扩散为主，而湖口区受微界面上微生物活动影响较大。利用梯度扩散薄膜技术（DGT）获取了水-沉积物界面上分辨率高达1mm的可溶性活性磷DRP剖面浓度分布，结果发现在湖口区沉积物表层2cm处有强烈磷释放现象，而在湖心区则未发现，这可能与含氧层厚度有着密切的联系，这一重要现象在常规尺度下可能被掩盖。

The effect of environmental micro-interface on internal phosphorus release of the lake

In order to reveal the behavior and mechanism of the environmental micro-interface from the source of pollution in lakes, from the point of view of environmental micro-interface in lake, we study the interfacial process of phosphorus in the three-phase structure model of the lake water-sediment interface. The oxygen micro-sensor and Diffusive Gradients in Thin-films were employed to obtain the vertical distribution of the dissolved oxygen and the dissolved reactive phosphorus (DRP) in high resolution, respectively. The result combined with Profile model was analyzed and calculated. We find that the aerobic layer thickness of sediment cores in central of Xuan-wu Lake is to 5mm, and that in the lakeshore is less than 3mm. oxygen consumption of the micro-interface in the central lake is mainly based diffusion, and in the lakeshore area that affected by the microbial activity in the micro-interface. From the vertical distribution in 1mm resolution of DRP in water-sediment interface by DGT device, results show that at the depth of 2cm in the sediment core from the lakeshore area has a strong releasing phosphorus phenomenon, but that in the central lake is not found, this may be closed linked with the aerobic layer thickness. However, this important phenomenon is covered in the conventional scale.