微电极测量系统在湖泊沉积物-水界面生物地球化学过程研究中的应用

Application of Microelectrode Measurement System in Research on Biogeochemical Processes across the Water-Sediment Interface in Hongfeng Lake

本文利用微电极测量系统对高原深水型湖泊红枫湖沉积物-水界面O2和H2S的微剖面分布进行了高分辨率研究。结果表明,红枫湖北湖中部和大坝沉积物-水界面扩散边界层厚度约为0.7mm,O2的扩散通量(J)分别为5.80和7.65mmol·m-2·d-1,O2的渗透深度分别为3.6±0.3mm和3.4±0.9mm,H2S的剖面变化主要受沉积物组成、O2消耗速率和硫酸盐还原菌(SRB)分布的影响。微电极测量系统具有原位测定、时空分辨率高、数据可靠性好等优点,在湖泊沉积物-水界面微尺度生物地球化学过程和驱动机制研究方面可发挥重要作用。

Micro-scale distributions of oxygen and H2S across the water-sediment interface in Lake Hongfeng,which is a deep lake in southwestern China,were measured with microelectrodes.Results showed that the diffusive fluxes,J,of O2 across the water-sediment interface in two sampling sites were respectively 5.80 and 7.65 mmol·m-2·d-1.Oxygen penetration depths in the sediments were 3.6±0.3 and 3.4±0.9 mm,respectively.Vertical distribution of H2S in the sediments was related with sediment composition,oxygen consumption rate and the activity of sulfate-reducing bacteria（SRB）.High-resolution microelectrode technique,whose determination results have been proved to be reliable,was of great value in the study of biogeochemical processes across the water -sediment interface in a lake.