Osmotically-assisted membrane processes (OAMP) are separation technologies that leverage osmotic gradients to recover water from brine. Accurate modeling of the solute-coupling effects for transmembrane transport is integral to the development and subsequent optimization of OAMP unit operations. In the literature, multicomponent transport in OAMP is commonly linearized, and species fluxes are computed using binary solution-diffusion theory and then superposed. However, recent publications highlight the large predictive errors associated with such an approach as the transport coupling between species is ignored. In this paper, we demonstrate that significant improvements in multicomponent species fluxes can be obtained when solute-coupling interactions are incorporated. Here, we present a multicomponent solution-diffusion model, by extending the binary solution-diffusion model with multicomponent diffusion theory. When multicomponent diffusion coefficients are available, we find that the average absolute deviation (AAD) of the model decreased from 21.0% to 3.0% for 7 unique combinations of forward osmosis processes involving ternary mixtures. In the absence of data for multicomponent diffusion coefficients, we demonstrate that the multicomponent model can regress the impact of transport coupling on water and solute fluxes, using excess solute permeabilities. For the case of H${}_2$O-NaCl-EtOH forward osmosis process, the AAD of the solution-diffusion model is shown to decrease from 66.1% to 7.2% for NaCl concentrations from 0.0 to 1.5 M and EtOH mass fractions from 0.0 to 0.5. These values are extended to analyze the implications on the thermodynamic and membrane area requirements of the desalination systems employing OAMP.

渗透辅助膜工艺 (OAMP) 是一种利用渗透梯度从盐水中回收水的分离技术。跨膜运输的溶质耦合效应的准确建模是 OAMP 单元操作的开发和后续优化不可或缺的一部分。在文献中，OAMP 中的多组分传输通常是线性化的，物种通量是使用二元解扩散理论计算的，然后叠加。然而，最近的出版物强调了与这种方法相关的大量预测误差，因为忽略了物种之间的传输耦合。在本文中，我们证明了当包含溶质耦合相互作用时，可以显着改善多组分物种通量。在这里，我们提出了一个多分量溶液扩散模型，通过用多组分扩散理论扩展二元溶液扩散模型。当多组分扩散系数可用时，我们发现模型的平均绝对偏差 (AAD) 从 21.0% 下降到 3.0%，用于涉及三元混合物的 7 种独特的正向渗透过程组合。在缺乏多组分扩散系数数据的情况下，我们证明多组分模型可以使用过量的溶质渗透率来回归传输耦合对水和溶质通量的影响。对于 H 的情况 在缺乏多组分扩散系数数据的情况下，我们证明多组分模型可以使用过量的溶质渗透率来回归传输耦合对水和溶质通量的影响。对于 H 的情况 在缺乏多组分扩散系数数据的情况下，我们证明多组分模型可以使用过量的溶质渗透率来回归传输耦合对水和溶质通量的影响。对于 H 的情况${}_2$在 O-NaCl-EtOH 正向渗透过程中，对于 NaCl 浓度从 0.0 到 1.5 M 和 EtOH 质量分数从 0.0 到 0.5，溶液扩散模型的 AAD 从 66.1% 减少到 7.2%。这些值被扩展到分析对使用 OAMP 的脱盐系统的热力学和膜面积要求的影响。