2020 Volume 76 Issue 2 Pages I_804-I_809
This study focus on the long-term improvement effect of sediment and water quality using granulated coal ash as sand covering material. To understand the effect, a field experiment and a laboratory experiment of the same scale and same time were conducted to compare the amount of sediment deposition, the ion concentration of pore water, and the change in the properties of the sediment.
From the field experiment, we revealed that sediment flows out of the granulated coal ash layer when the water temperature difference between the inside and outside the layer reverses and the amount of sediment deposition was smaller than in the gravel layer. The calcium ion concentration in the pore water and the amount of adsorbed calcium ion of sediment were high in both field and laboratory experiments. From these results, it is suggested that the decreasing of the amount of sediment deposition in the granulated coal ash layer was caused by local scale phenomena such as density inversion and tide level change in addition to sediment property change.
