Huisman Jacco L, Weber Nicole, Gujer Willi
Swiss Federal Institute of Environmental Research (EAWAG), Postbox 611, CH-8600 Dübendorf, Switzerland.
Water Res. 2004 Mar;38(5):1089-100. doi: 10.1016/j.watres.2003.11.025.
The sewer system is a very dynamic system with an abundance of mass transfer processes and transformations. A key process is the mass exchange between the wastewater and the sewer atmosphere. An equation that describes the gas-liquid mass transfer under different hydrodynamic conditions is essential when sewer processes are to be quantified or modelled. In this work, a calibrated reaeration equation is proposed. It is based on the shear Reynolds and the Froude number to correct the increased gas-liquid interface roughness to higher flow rates. The equation was calibrated with previously published data and with new data. This data was obtained with a safe and environmentally friendly gas tracer method for gravity sewers based on the inert gas sulphur hexafluoride (SF6), a new method for the sewer system. Measurements were conducted in four channels under different conditions. The resulting equation will allow for more accurate simulations of the sewer system. Finally, the effect of reaeration with regard to the oxygen consuming processes for different hydrodynamic conditions is discussed.
下水道系统是一个非常动态的系统，存在大量的传质过程和转化。一个关键过程是废水与下水道空气之间的质量交换。当需要对下水道过程进行量化或建模时，一个描述不同水动力条件下气液传质的方程至关重要。在这项工作中，提出了一个校准后的复氧方程。它基于剪切雷诺数和弗劳德数，以校正较高流速下增加的气液界面粗糙度。该方程用先前发表的数据和新数据进行了校准。这些数据是通过一种基于惰性气体六氟化硫（SF6）的安全且环保的气体示踪剂方法获得的，这是一种用于下水道系统的新方法。在四个不同条件的渠道中进行了测量。所得方程将使下水道系统的模拟更加准确。最后，讨论了不同水动力条件下复氧对耗氧过程的影响。
