Maraqa M A
Department of Civil Engineering, College of Engineering, United Arab Emirates University, Al-Ain.
J Contam Hydrol. 2001 Dec 1;53(1-2):153-71. doi: 10.1016/s0169-7722(01)00198-x.
Several previously reported laboratory studies related to transport of solutes through packed columns were utilized to develop predictive relationships for mass-transfer rate coefficient. The data were classified into two groups: those obtained under rate-limited mass transfer between mobile and immobile water regions (physical nonequilibrium conditions), and those derived from rate-limited mass transfer between instantaneous and slow sorption sites (sorption nonequilibrium conditions). The mass-transfer coefficient in all these studies was obtained by fitting breakthrough data to a transport model employing a first-order rate limitations with a "constant" mass-transfer coefficient, independent of flow conditions. This study demonstrated that the mass-transfer coefficient in these models is dependent on system parameters including pore-water velocity, length-scale, retardation coefficient, and particle or aggregate size. Predictive relationships were developed, through regression analysis, relating mass-transfer coefficient to residence time. The developed relationships adequately estimated previously reported field mass-transfer values. Successful simulations of field desorption data reported by Bahr [J. Contam. Hydrol. 4 (1989) 205] further demonstrate the potential applicability of the developed relationships.
利用先前报道的几项与溶质通过填充柱传输相关的实验室研究，来建立传质速率系数的预测关系。数据分为两组：一组是在流动水区域和非流动水区域之间的传质受速率限制（物理非平衡条件）下获得的数据，另一组是来自瞬时吸附位点和慢速吸附位点之间的传质受速率限制（吸附非平衡条件）的数据。在所有这些研究中，传质系数是通过将穿透数据拟合到一个采用一阶速率限制且具有“恒定”传质系数（与流动条件无关）的传输模型来获得的。本研究表明，这些模型中的传质系数取决于系统参数，包括孔隙水速度、长度尺度、阻滞系数以及颗粒或聚集体大小。通过回归分析建立了传质系数与停留时间之间的预测关系。所建立的关系充分估计了先前报道的现场传质值。对Bahr [《污染水文杂志》4 (1989) 205]报道的现场解吸数据的成功模拟，进一步证明了所建立关系的潜在适用性。
