Author(s): Lei Wu; Dongdong Jia; Xingnong Zhang; Youzhi Hao; Jun Yang
Linked Author(s):
Keywords: No keywords
Abstract: The impact of sediment stability on the aquatic environment of shallow lakes has received increasing attention from researchers, especially at the sediment-water interface (SWI). The stability of sediments includes both the sediment particles themselves and various environmental substances adsorbed by particles and interstitial water, especially nitrogen and phosphorus concentrations are critical to the problem of cyanobacterial blooms in eutrophic lakes. Factors affecting sediment stability include the combined effects of waves and currents, particle size and volume characteristics of the bed material, and biostability or bioturbation. The hydrodynamic changes caused by wind and waves and ship sailing are the direct factors of sediment resuspension in shallow Lake. This study analyzed the relationship between the amount of sediment resuspension and the release fluxes of dissolved total nitrogen (DTN) and dissolved total phosphorus (DTP) under different rotational speed perturbations. The shear stress generated at 0 rpm and 100 rpm were limited and the sediments were substantially not resuspended. Significant resuspension of the sediment occurred under shear disturbance at 200-400 rpm. After 20 minutes of shearing at 200 rpm and 300 rpm, the amount of sediment resuspension basically reached a steady state, indicating that the shear stress generated by stirring and the stabilization force inside the sediment basically reached a balance. The release fluxes of DTN and DTP increased with the increase of shear speed, and with the increase of shear strength, but the growth rate of DTN and DTP release fluxes became slower with the increase of shear speed.
Year: 2022