The exchange of dissolved substances between mud and water in lakes
The exchange of dissolved substances between mud and water in lakes
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DOI：
10.2307/2256395
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发表时间：
1941-01-01
影响因子：
5.5
通讯作者：
Mortimer, CH
中科院分区：
文献类型：
--
作者：
Mortimer, CH
关于在湖泊底层泥-水界面发生的物理-化学变化以及各种营养物质对来自底层沉积物的水的贡献的研究报告。对Esthwaite水进行了定期观察，并进行了实验室试验。并获得其他湖泊的数据进行比较。研究了4个物理因子和16个化学因子。特别注意的化学变化发生在较低的水开始后，热分层。随着季节的推进，O2的还原在该地层中产生还原条件，如氧化还原电位的变化所示。在这些还原条件下，泥浆中的某些物质溶解，这些溶质向上移动到水中，主要是由于涡流扩散。假设所有的溶质都来自泥浆，估计平均涡流扩散系数。对于选定的水平是各自的分子系数的20至2000倍。热传导和化学扩散的影响;即使在冬季，当湖面被冰覆盖时，涡流扩散系数。是分子系数的200倍泥浆表面的减小和相应的溶质向水中的供应的增加取决于泥浆的还原能力和amt。提供给泥浆表面的氧气。在10月秋季推翻的时候，溶质分布在整个湖泊中，因此可供浮游植物利用。
Report of a study of the physical-chemical changes which take place at the mud-water interface in the hypolimnion of lakes and the resulting contributions of various nutritive substances to the water from the bottom deposits. Regular observations were made on Esthwaite Water, with laboratory expts. and data on other lakes obtained for comparison. 4 physical and 16 chemical factors were studied. Particular attention was given to the chemical changes taking place in the lower water after the onset of thermal stratification. As the season advanced the reduction of the O2 produced reducing conditions in this stratum as shown by the change in redox potential. Under these reducing conditions certain substances in the mud dissolved and these solutes moved upward into the water, due chiefly to eddy diffusion. Assuming that all of the solutes came from the mud, it was estimated that the mean eddy diffusion coeff. for selected levels was 20 to 2000 times the respective molecular coeffs. of heat conduction and chemical diffusion; even in winter when the lake was covered with ice, the eddy diffusion coeff. was > 200 times the molecular coeff. The reduction of the mud surface and the associated increase in the supply of solutes to the water depend upon the reducing power of the mud and the amt. of O2 supplied to the mud surface. At the time of the autumnal overturn in Oct., the solutes are distributed throughout the lake and thus become available to the phytoplankton.