Abstract Hemodialysis consumes significant amounts of pure water and produces large amounts of spent dialysate. Recovering water from spent dialysate is a new attempt in medical industries to save water and costs. The recent proposal of using forward osmosis (FO) to concentrate the spent dialysate showed economic viability. However, there is still one key concern of potentially extended hemodialysis duration because commercial FO membranes have limited urea rejection, which would reduce the urea concentration gradient during hemodialysis. In this paper, a model was developed to quantify the effect of incomplete urea rejection in FO on subsequent hemodialysis duration. The impacts of average urea rejection, water recovery, and the number of hemodialysis sessions were systematically analyzed. Counter-intuitively, the results indicated that relatively low urea rejection of FO membranes actually has little impact on hemodialysis duration. Low urea concentration in the spent dialysate, partial urea rejection by the FO membrane, and further dilution of pre-diluted dialysis concentrate, largely reduces this impact. The result further supports the viability of FO in spent dialysate reuse. Although FO membrane with 100% rejection is expected, the present work indicates that commercial FO membranes with a low rejection of neutral matters are of practical utility in certain applications.

中文翻译：

---

通过渗透稀释从废透析液中回收水：正渗透膜的尿素排斥对血液透析持续时间的影响

摘要 血液透析消耗大量纯水并产生大量废透析液。从废透析液中回收水是医疗行业节约用水和成本的新尝试。最近使用正向渗透 (FO) 浓缩废透析液的提议显示出经济可行性。然而，仍然存在潜在延长血液透析持续时间的一个关键问题，因为商业 FO 膜具有有限的尿素排斥，这会降低血液透析过程中的尿素浓度梯度。在本文中，开发了一个模型来量化 FO 中不完全尿素排斥对后续血液透析持续时间的影响。系统分析了平均尿素排斥、水回收和血液透析次数的影响。与直觉相反，结果表明，相对较低的 FO 膜的尿素排斥实际上对血液透析持续时间几乎没有影响。废透析液中的低尿素浓度、FO 膜对尿素的部分排斥以及预稀释的透析浓缩液的进一步稀释，在很大程度上降低了这种影响。结果进一步支持 FO 在废透析液再利用中的可行性。尽管预期具有 100% 截留率的 FO 膜，但目前的工作表明，具有低中性物质截留率的商业 FO 膜在某些应用中具有实际效用。结果进一步支持 FO 在废透析液再利用中的可行性。尽管预期具有 100% 截留率的 FO 膜，但目前的工作表明，具有低中性物质截留率的商业 FO 膜在某些应用中具有实际效用。结果进一步支持 FO 在废透析液再利用中的可行性。尽管预期具有 100% 截留率的 FO 膜，但目前的工作表明，具有低中性物质截留率的商业 FO 膜在某些应用中具有实际效用。