| 水体扰动条件下物质在沉积介质中的迁移 |
| 摘要点击 1585 全文点击 1003 投稿时间：2014-10-14 修订日期：2015-05-11 |
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| 中文关键词 均质 对流 孔隙压差 扰动 罗丹明B |
| 英文关键词 homogeneous sediment convection pore pressure disturbance Rhodamine B |
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| 中文摘要 |
| 为了研究在上覆水体扰动条件下物质在沉积介质中的迁移,本实验建立了简单的沉积物再悬浮发生装置,并分别利用不同粒径大小的沙粒作为均质沉积物,同时利用500 μg·cm-3的溶解性罗丹明B作为示踪剂,观察在紊流扰动条件下物质在不同的均匀沉积介质中的迁移情况. 结果表明,在粒径不同的各类沉积介质中,由于不同颗粒的孔隙度、渗透率不同,在各沉积介质中形成的孔隙水压力差产生了孔隙水对流现象,从而导致了物质在多孔介质中发生垂向或水平迁移,并且其平均迁移速度受到染色剂的埋深和多孔介质的粒径大小的影响. 而在均匀的沉积层中,200 r·min－1的扰动主要影响各沉积介质中物质的垂向迁移,并且当适当增加介质的粒径时,这种垂向对流迁移现象相对增强. |
| 英文摘要 |
| To examine mass transport in porous sediments during a turbulent flow, we established a simple sediment re-suspension device, made use of different sizes of sands as homogeneous sediments, and we injected 500 μg·cm-3 soluble Rhodamine B into different parts of the sediment as the mass tracer, to observe mass transport during the turbulent condition.The research showed that in porous sediments, pore-water pressure difference would be generated because of the sediments' distinctive porosity and permeability, and further led to the convective flow and mass transport in porous media.Moreover, such mass transport was directly influenced by its burial depth and particle size of the sediment.While in homogeneous sediments, mass transport was strongly influenced in vertical direction under 200 r·min-1 disturbance, and when moderately increased the size of porous particles under the same turbulent condition, such convection of pore-water would relatively enhance. |
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