Dissolved Oxygen Demand at the Sediment-Water Interface of a Stream: Near-Bed Turbulence and Pore Water Flow Effects
Dissolved Oxygen Demand at the Sediment-Water Interface of a Stream: Near-Bed Turbulence and Pore Water Flow Effects
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DOI：
10.1061/(asce)ee.1943-7870.0000368
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发表时间：
2011-07
影响因子：
2.2
通讯作者：
Makoto Higashino;H. Stefan
中科院分区：
文献类型：
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作者：
Makoto Higashino;H. Stefan
建立了一个考虑床层湍流和多孔床层孔隙水流动影响的微生物溶解氧（DO）吸收模型。细粒沉积物床层的导水率为0.01≤k≤1 cm/s，即，泥沙粒径0.006≤ds≤0.06 cm。孔隙水流动是由沉积物-水界面处的压力波动驱动的，主要归因于沉积物床上方湍流边界层中的近床相干运动。有效传质系数（De）耦合到孔隙水流动模型中使用的溶解氧传输和溶解氧吸收模型。溶解氧通过沉积物-水界面进入沉积物的通量，即，沉积物需氧量（SOD）与沉积物中的水力传导率和微生物耗氧速率以及沉积物-水界面处的剪切速度有关。模拟SOD值进行了验证，对实验数据。当导水率k ≤ 0.01cm/s时，孔隙水流速k ≤ 0.01cm/s时，孔隙水流速k ≤ 0.01cm/s。
A microbial dissolved oxygen (DO) uptake model was developed for a stream bed, including the effect of turbulence in the flow over the bed and pore water flow in the porous bed. The fine-grained sediment bed has hydraulic conductivities 0.01≤k≤1 cm/s, i.e., sediment particle diameter 0.006≤ds≤0.06 cm. The pore water flow is driven by pressure fluctuations at the sediment-water interface, mostly attributable to near-bed coherent motions in the turbulent boundary layer above the sediment bed. An effective mass transfer coefficient (De) coupled to a pore water flow model was used in the DO transport and DO uptake model. DO flux across the sediment-water interface and into the sediment, i.e., sedimentary oxygen demand (SOD), was related to hydraulic conductivity and microbial oxygen uptake rate in the sediment and shear velocity at the sediment-water interface. Simulated SOD values were validated against experimental data. For hydraulic conductivities of the sediment bed up to k≈0.01 cm/s, the pore water f...