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,研究湖泊沉积物一水微界面磷的释放过程。利用新兴的湖泊沉积物原位高分辨率间隙水采集技术(DGT和Mini—peeper)分别获取了大纵湖、蜈蚣湖和九龙口沉积环境中生物有效磷和可溶性活性磷的垂直剖面分布,并在微尺度下发现了由局部有机质强烈降解释放磷酸盐形成的异常突变点。利用DIFS模型分析了沉积物对磷的吸附解吸特性,结果发现:疏浚后的九龙口沉积物对磷酸盐的吸附解吸能力较弱,而大纵湖和蜈蚣湖表层沉积物磷酸盐则以弱结合态为主,具有良好的磷吸附特性,表明稳定的沉积物表层环境微界面系统对内源磷的释放具有很好的缓冲作用;同时发现大纵湖和蜈蚣湖表层沉积物对间隙水中的磷具有较强的补给能力,补给源主要分布在沉积物表层2~3cm附近,对界面磷的释放起关键的调节作用。
In order to reveal the behavior and mechanism on the micro-interface of the internal pollution in lakes, from an environmental micro-interface perspective, the phosphorus release process of sediment-wa- ter micro-interface was studied. Diffusive Gradients in Thin-films and Mini-peeper technology is used to collect the biological effective phosphorus and soluble active phosphorus for their vertical distribution in sedi- mentary environment from three lakes of Dazong, Wugong and Jiulongkou. Under the microscale, some ab- normal mutation points have been found, which are formed by strong local organic matter degradation of phosphate release. Adsorption and desorption characteristics of phosphorus in sediments was calculated by us- ing the DIFS model, the results show that adsorption and desorption ability of phosphate in dredged Ji- ulongkou Lake sediment is week, and phosphates in overlying deposit of Dazong and Wugong lakes are mainly in week bound with good adsorption properties. It shows that the stable micro-environment interface system on the sediment surface has a good buffer effect. The sediment of Dazong and Wugong lakes have a strong supply capacity, the sources are mainly distributed in the surface near 2-3 cm, which play a key role in the regulation of interface for phosphorus release.