STUDY ON CONTAMINANT TRANSPORT AT THE SEDIMENT-WATER INTERFACE IN OSCILLATING FLOW

被引：0
|
作者：
Chen J. [1 ]
Zhang J. [1 ]
Yang W. [1 ]
Dong Y. [1 ]
机构：
[1] Shanghai Institute of Applied Math & Mech, School of Mechanics and Engineering Science, Shanghai University, Shanghai
来源：
Lixue Xuebao/Chinese Journal of Theoretical and Applied Mechanics | 2022年 / 54卷 / 10期
关键词：
hyporheic exchange; large eddy simulation; oscillatory flow; permeable sediment; zinc ions;
D O I：
10.6052/0459-1879-22-227
中图分类号：
学科分类号：
摘要：
The exchange and transport characteristics of pollutants in the hyporheic zone are one of the important issues affecting the water resources environment. In this paper, the high Schmidt number mass transfer phenomenon of a channel oscillatory flow with a highly permeable sediment layer at the bottom is numerically investigated by using large eddy simulations. A modified Darcy-Brinkman-Forcheimer model describes the bottom highly permeable sediment layer using the volume-averaged Navier-Stokes equation and convective diffusion equation for the flow and transport of metal ion contaminants within the sediment layer. We explore the statistical characteristics and the instantaneous structure of flow field and concentration field, and the dynamic influence of oscillating flow inside and outside the sediment-water interface on the transport of pollutants. In addition, the variation of the effective diffusivity at the sediment-water interface with oscillation period and oscillation angle is also studied. The results show that the turbulence component of concentration flux plays a dominant role in vertical mass transport, and the streamwise and spanwise velocity, the fluctuations of turbulence intensity and pollutant concentration follow the quasi-periodic variation of periodic oscillation driving force. At the same time, it is found that there is a clear correlation between the variation of turbulent concentration flux at the sediment-water interface and the intensity of normal turbulence, and the effective diffusivity at the sediment-water interface increases at larger oscillation angles and low-frequency oscillations, which mainly comes from the burst behavior of the fluid at the sediment-water interface that significantly promotes turbulent mixing and material exchange, and then the concentration scalar is acted on by a convection-diffusion mechanism, which in turn enhances the vertical mass transport of pollutants. © 2022 Chinese Journal of Theoretical and Applied Mechanics Press. All rights reserved.
引用
下载
收藏
页码：2773 / 2783
页数：10
相关论文
共 33 条
  • [1] Islam MS, Hossain MB, Matin A, Et al., Assessment of heavy metal pollution, distribution and source apportionment in the sediment from Feni River estuary, Bangladesh, Chemosphere: Environmental Toxicology and Risk Assessment, 202, pp. 25-32, (2018)
  • [2] Huang XF, Hu JW, Li CX, Et al., Heavy-metal pollution and potential ecological risk assessment of sediments from Baihua Lake, Guizhou, P R China, International Journal of Environmental Health Research, 19, 6, pp. 405-419, (2009)
  • [3] Jia YY, Wang L, Qu ZP, Et al., Distribution, contamination and accumulation of heavy metals in water, sediments, and freshwater shellfish from Liuyang River, Southern China, Environmental Science and Pollution Research, 25, pp. 7012-7020, (2018)
  • [4] Zhao GM, Ye SY, Yuan HM, Et al., Surface sediment properties and heavy metal contamination assessment in river sediments of the Pearl River Delta, China, Marine Pollution Bulletin, 136, pp. 300-308, (2018)
  • [5] Liang Peiyu, Wang Xuan, Ma Fangbing, Effect of hydrodynamic conditions on water eutrophication: A review, Journal of Lake Science, 25, pp. 455-462, (2013)
  • [6] Zhao Jianqi, A theoretial analysics on phenomenon of science, College Physics, 11, pp. 12-13, (1998)
  • [7] Gundersen JK, Jorgensen BB., Microstructure of diffusive boundary layers and the oxygen uptake of the sea floor, Nature, 345, pp. 604-607, (1990)
  • [8] Higashino M, Stefan HG., Diffusive boundary layer development above a sediment-water interface, Water Environment Research, 76, pp. 292-300, (2004)
  • [9] Jabbari A, Boegman L., Parameterization of oscillating boundary layers in lakes and coastal oceans, Ocean Modelling, 160, pp. 101-780, (2021)
  • [10] Spalart PR, Baldwin BS., Direct simulation of a turbulent oscillating boundary layer, Turbulent Shear Flows 6, pp. 417-440, (1989)
1234