Xie Peng, Cath Tzahi Y, Ladner David A
Department of Environmental Engineering and Earth Sciences, Clemson University, Clemson, SC 29625, USA.
Department of Civil and Environmental Engineering, Colorado School Mines, Golden, CO 80401, USA.
Membranes (Basel). 2021 Jan 1;11(1):29. doi: 10.3390/membranes11010029.
Forward osmosis (FO) and pressure retarded osmosis (PRO) are the two operational modes for osmotically driven membrane processes (ODMPs). ODMPs have gained increasing popularity in the laboratory over the years; however, OMDPs have not been applied in very many cases at full scale because they are still emerging technologies that require further development. Computational fluid dynamics (CFD) modeling coupled with solute transport evaluation provides a tool to study hydrodynamics and concentration polarization in FO and PRO. In this study a series of models were developed to predict water flux. The simulation results of empty-channel (with no feed spacer) membrane cells were verified by comparison with experimental results, showing that CFD simulation with solute transport is a reliable tool. Ensuing 2D and 3D models were built to study the impact of feed spacers on the velocity and concentration distribution inside the flow channels, and investigate whether the presence of spacers would enable enhancement of water flux. The results showed that spacers could change the concentration and velocity profile and they could reduce or enhance water flux depending on the inlet flow velocity and distance between the membrane and spacer.
正向渗透（FO）和压力延迟渗透（PRO）是渗透驱动膜过程（ODMPs）的两种操作模式。多年来，ODMPs在实验室中越来越受欢迎；然而，由于它们仍是需要进一步发展的新兴技术，在很多情况下尚未得到大规模应用。计算流体动力学（CFD）建模结合溶质输运评估提供了一种研究FO和PRO中流体动力学和浓差极化的工具。在本研究中，开发了一系列模型来预测水通量。通过与实验结果比较，验证了无进料间隔物的空通道膜池的模拟结果，表明结合溶质输运的CFD模拟是一种可靠的工具。随后建立了二维和三维模型，以研究进料间隔物对流道内速度和浓度分布的影响，并研究间隔物的存在是否能提高水通量。结果表明，间隔物可以改变浓度和速度分布，并且根据入口流速以及膜与间隔物之间的距离，它们可以降低或提高水通量。
