The rising demand for sustainable wastewater management and high-value resource recovery is pressing industries involved in, e.g., textiles, metals, and food production, to adopt energy-efficient and flexible liquid separation methods. The current techniques often fall short in achieving zero liquid discharge and enhancing socio-economic growth sustainably. Osmotic membrane distillation (OMD) has emerged as a low-temperature separation process designed to concentrate valuable elements and substances in dilute feed streams. The efficacy of OMD hinges on the solvent’s migration from the feed to the draw stream through a hydrophobic membrane, driven by the vapor pressure difference induced by both temperature and concentration gradients. However, the intricate interplay of heat and mass processes steering this mechanism is not yet fully comprehended or accurately modeled. In this research, we conducted a combined theoretical and experimental study to explore the capabilities and thermodynamic limitations of OMD. Under diverse operating conditions, the experimental campaign aimed to corroborate our theoretical assertions. We derived a novel equation to govern water flux based on foundational principles and introduced a streamlined version for more straightforward application. Our findings spotlight complex transport-limiting and self-adjusting mechanisms linked with temperature and concentration polarization phenomena. Compared with traditional methods like membrane distillation and osmotic dilution, which are driven by solely temperature or concentration gradients, OMD may provide improved and flexible performance in target applications. For instance, we show that OMD—if properly optimized—can achieve water vapor fluxes 50% higher than osmotic dilution. Notably, OMD operation at reduced feed temperatures can lead to energy savings ranging between 5 and 95%, owing to the use of highly concentrated draw solutions. This study underscores the potential of OMD in real-world applications, such as concentrating lithium in wastewater streams. By enhancing our fundamental understanding of OMD’s potential and constraints, we aim to broaden its adoption as a pivotal liquid separation tool, with focus on sustainable resource recovery.

对可持续废水管理和高价值资源回收的需求不断增长，迫使纺织、金属和食品生产等行业采用节能且灵活的液体分离方法。目前的技术往往无法实现零液体排放和可持续地促进社会经济增长。渗透膜蒸馏 (OMD) 已成为一种低温分离工艺，旨在浓缩稀原料流中的有价值的元素和物质。OMD 的功效取决于溶剂通过疏水膜从进料流迁移到抽取流的过程，这是由温度和浓度梯度引起的蒸气压差驱动的。然而，控制这一机制的热量和质量过程的复杂相互作用尚未被完全理解或准确建模。在这项研究中，我们进行了理论和实验相结合的研究，以探索 OMD 的功能和热力学局限性。在不同的操作条件下，实验活动旨在证实我们的理论主张。我们根据基本原理推导了一个新颖的方程来控制水通量，并引入了一个简化的版本以实现更直接的应用。我们的研究结果强调了与温度和浓差极化现象相关的复杂的传输限制和自我调节机制。与仅由温度或浓度梯度驱动的膜蒸馏和渗透稀释等传统方法相比，OMD 可以在目标应用中提供改进且灵活的性能。例如，我们表明，如果适当优化，OMD 可以实现比渗透稀释高 50% 的水蒸气通量。值得注意的是，由于使用高浓度的汲取溶液，在降低进料温度下进行 OMD 操作可节省 5% 至 95% 的能源。这项研究强调了 OMD 在实际应用中的潜力，例如浓缩废水流中的锂。通过增强我们对 OMD 潜力和限制的基本了解，我们的目标是扩大其作为关键液体分离工具的采用范围，重点关注可持续资源回收。