Development of sampling system for consolidated mud and understanding on settling mechanism of floating mud using the sampling system

固结泥浆取样系统的开发及利用取样系统了解浮泥沉降机理

• 批准号: 14350269
• 负责人: HIBINO Tadashi
• 金额: $ 7.74万
• 依托单位: HIROSHIMA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14350269/
• 关键词: pore water movement; high turbidity layer generation; upwelling of floating mud; DO Respiration; ground water level; stratification; weight of sea water; 高濁質層の形式; 底泥の巻き上げ; 海底浮遊泥; 堆積密度; 間隙水流動; 採泥器; 栄養塩; 巻き上がり; 閉鎖性海域

By investigating the sediment at the sea bottom of the Hiroshima Bay, we were able to show the seasonal change mechanism of the sediment with the pore water movement.The turbidity increasing does not only depend on the velocity above the bottom but also on the movement of pore water in the consolidated sediment. According to the experiment, the fluid mud doesn't well up when the velocity of under 6cm/s is occurred above the bed. In these results, the bottom flow, observed at the head of Hiroshima Bay, cannot cause the upwelling of the bottom sediment.Wet density, water content and specific gravity in surface sediment seasonally changed in over 20 cm depths. Water content increased more from summer to fall, and was over 500% at the fluid mud layer in fall. The high turbidity is generated in water content increasing period.The generation process of the high turbidity is hypothesized that firstly, the pressure different between sea and ground generates in the stratified season because of the water heating etc., secondly, the pore water moves cyclically with tide, finally, the fluid mud wells up with the pore water flowing up from the sediment.In the consolidated sediment, DO above the sediment are consumed resulting to oxygen-deficient water mass occurs at the sea bottom. According to the numerical simulation, the estimated amounts of the pore water moving explain the turbidity variation and water content profiles of the sediment. These phenomena can be explained by the pore water movement between the sea above the bottom and the sediment layer.

通过对广岛湾海底沉积物的研究，揭示了沉积物随孔隙水运动的季节变化机制，浊度的增加不仅取决于海底以上的流速，还取决于固结沉积物中孔隙水的运动。实验表明，当床面以上流速小于6 cm/S时，浮泥不能很好地上浮。在这些结果中，在广岛湾头部观测到的底流不会引起底层沉积物的上升流。表层沉积物的湿密度、含水率和比重在20厘米以上的深度具有季节性变化。夏季至秋季含水率增加幅度较大，秋季浮泥层含水率在500%以上。高浊度的产生是在含水率增加的时期，高浊度的产生过程假设首先是由于水的加热等原因在分层季节产生海地差压力，其次是孔隙水随潮汐循环运动，最后浮泥随沉积物中的孔隙水向上涌出，在固结沉积物中，沉积物上方的DO被消耗，导致海底出现缺氧水团。根据数值模拟，估算的孔隙水运移量解释了沉积物的浊度变化和含水率剖面。这些现象可以用海底以上的海洋与沉积层之间的孔隙水运动来解释。

项目成果

Setting Process of Suspended Particulate Matter in Hiroshima Bay

广岛湾悬浮颗粒物的沉降过程

• 发表时间: 2005
• 期刊: Annual Journal of Coastal Engineering, JSCE Vol.52 (2)
• 作者: Tatsuhito Kono;Takayuki Kaneko;Hisayoshi Morisugi;Satoshi Sasakura
• 通讯作者: Satoshi Sasakura

The Sediment Variations under the Flow of Pore Water

孔隙水流动下沉积物的变化

• 发表时间: 2004
• 期刊: Annual Journal of Coastal Engineering, JSCE Vol.,51(2)
• 作者: Kazufumi Tada

底泥内での間隙水の動きと浮泥層の形成機構

底泥孔隙水运动及浮泥层形成机制

• 发表时间: 2005
• 期刊: 海岸工学論文集 52(2)
• 作者: Takayuki Ueda;Ma.Sheila A.Gaabucayan;Hisayoshi Morisugi;A.S.Shannigrahi;日比野忠史
• 通讯作者: 日比野忠史

Emission and dispersion of PAHs from heavy traffic road

交通繁忙道路多环芳烃的排放和扩散

• 发表时间: 2003
• 期刊: Air Pollution XI
• 作者: 日比野忠史;Noriatsu Ozaki
• 通讯作者: Noriatsu Ozaki

A study on sludge accumulation mechanism on flat sheet membrane surface in submerged membrane bioreactor

浸没式膜生物反应器平板膜表面污泥堆积机理研究

• 发表时间: 2003
• 期刊: Proceedings of International Conference on Civil and Environmental Engineering ICCEE-2003
• 作者: 日比野忠史;Noriatsu Ozaki;Noriatsu Ozaki
• 通讯作者: Noriatsu Ozaki