GOALI: Novel Thin Film Composite Membranes for Desalination by Forward Osmosis

GOALI：用于正向渗透海水淡化的新型薄膜复合膜

• 批准号: 1067564
• 负责人: Jeffrey McCutcheon
• 金额: $ 30万
• 依托单位: University of Connecticut
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-15 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1067564&HistoricalAwards=false
• 关键词: GOALI; Novel; Thin; Film; Composite

1067564McCutcheonAn increasingly arid world requires the innovation of sustainable technologies to produce potable water from impaired and saline water sources. Existing desalination technologies, like reverse osmosis (RO), remain an unsustainable option due to high energy costs and environmentally harmful brine discharges. Forward osmosis (FO) is an innovative and sustainable desalination alternative that promises to provide potable water from saline water sources at radically reduced cost, energy consumption, and brine discharge. Unlike RO, which requires a hydraulic driving force for separation, FO utilizes an osmotic driving force generated by a draw solution. The novelty of FO lies in the use of NH3-CO2 salts as a draw solute. These salts were identified by the PI and co-PI for their osmotic efficiency (capable of generating osmotic pressures up to 3,000 psi or 7,000 ft of head) and easy removal and reuse using only low grade waste heat (down to 40°C). The single obstacle to the successful commercialization of FO technologies is the poor productivity of existing salt-rejecting membranes due to a severe mass transfer limitation known as internal concentration polarization. The University of Connecticut (UConn) and Oasys WaterTM (Oasys) are combining their efforts to enable this transformational technology by considering revolutionary thin film composite (TFC) membrane designs that will mitigate the effects of this debilitating phenomenon. Key technical areas of innovation, identified by the PI and co-PI in previous efforts, are focused on making the membrane supporting structure thinner, more porous and less tortuous. This proposed work considers the implementation of electrospun nanofiber nonwovens as novel support structures in next generation TFC membranes tailored for NH3-CO2 forward osmosis. Electrospinning is a method that is commonly used to create highly porous and thin nanofibrous nonwoven materials. This project is the first effort to apply this unique structure with tunable properties in TFC membranes for FO applications. The nanofiber nonwoven will serve to anchor a crosslinked polyamide barrier layer deposited by in situ polymerization of m-phenylenediamine. The resulting TFC membranes will be characterized and evaluated for flux and selectivity performance. FO flux modeling techniques, developed by the PI, will be used to determine the severity of internal concentration polarization and provide input for future iterations of membrane design. This effort will for the first time employ an electrospun nanofiber nonwoven as a support structure for a TFC membrane tailored for FO. This work will further enable FO, an emerging membrane technology, to deliver on promised results of lower water cost and higher recovery. Constructing these membranes in the laboratory will require a comprehensive approach that will consider all aspects of the electrospun support fabrication and polyamide selective layer formation, thus requiring a unique combination of expertise in polymer science, nanotechnology, and mass transport. This project will also result in fundamental understanding of how the support layer structure impacts the in situ polymerization process and the performance of the resulting film. The PI and co-PI, both considered world experts on FO, are uniquely suited to complete this proposed work. Both have access to facilities and expertise that are customized specifically for the tasks outlined in this proposal. This emerging technology platform will serve as an excellent educational tool for students at UConn. Forward osmosis is a multistep process which relies on several unit operations. We will thus specifically integrate forward osmosis into the Chemical Engineering capstone Senior Design Course, giving multiple groups an opportunity to compete for the best design configuration which uses the least energy and has the lowest capital cost. This effort will be of interest to Oasys, which will sponsor an internship program for UConn engineering students that will facilitate the employment of engineers from UConn as well as foster a long term academic-industrial partnership. A safe and sustainable water supply in the 21st century is the most daunting task humanity faces with regards to public health. We must augment our existing water supplies through the treatment of compromised sources with sustainable and affordable technologies like FO. Nowhere are these issues more relevant than in the developing world. The PI will thus embark on a unique project in collaboration with the UConn chapter of Engineers without Borders (EWB) to install commercial FO systems in Ethiopia as remote water purifiers and teaching tools. This effort will be part of an existing US Agency for International Development/Higher Education (US-AID/HED) project conducted through UConn.

1067564 McCutcheonan日益干旱的世界要求可持续技术的创新，以从受损和盐水来源的水源中生产饮用水。由于高能源成本和环境有害的盐水排放，现有的脱盐技术，例如反渗透（RO），仍然是不可持续的选择。正向渗透（FO）是一种创新且可持续的淡化替代方案，有望以大大降低的成本，能源消耗和盐水排放从盐水来源提供饮用水。与RO不同，RO需要将水解驱动力进行分离，而FO则利用了通过拉动溶液产生的渗透驱动力。 FO的新颖性在于使用NH3-CO2盐作为抽奖溶液。这些盐是通过PI和Co-Pi鉴定出的渗透效率（能够产生高达3,000 psi的渗透压或7,000英尺的头部），并且仅使用低级废热（降至40°C），易于清除和重复使用。 FO技术成功商业化的唯一障碍是由于严重的传质限制（称为内部浓度极化），现有的盐浸润膜的差异很差。康涅狄格大学（UCONN）和OASYS WATERTM（OASYS）通过考虑革命性的薄膜复合材料（TFC）膜设计，将他们的努力结合起来，以减轻这种衰弱现象的影响。 PI和Co-Pi在以前的努力中确定的创新的关键技术领域是使膜支撑结构更薄，更多孔和曲折的膜。这项拟议的工作认为，在下一代TFC膜中，电纺纳米纤维非织造的实施是针对NH3-CO2向前渗透量身定制的新型支撑结构。静电纺丝是一种通常用于产生高度多孔和薄的纳米纤维非织造材料的方法。该项目是将这种独特的结构应用于FO应用中的TFC膜中具有可调性的第一个努力。纳米纤维非织造将用于锚定通过M-苯基二胺的原位聚合沉积的交联的聚酰胺屏障层。所得的TFC膜将被表征并评估用于通量和选择性性能。由PI开发的FO通量建模技术将用于确定内部浓度极化的严重性，并为未来的膜设计迭代提供输入。这项工作将在第一次员工中使用电动传播纳米纤维非织造作为量身定制的FO的TFC膜的支撑结构。这项工作将进一步使新兴的膜技术FO能够提供较低的水成本和更高恢复的希望结果。在实验室中构建这些膜将需要一种全面的方法，该方法将考虑电纺支持制造和多酰胺选择性层形成的各个方面，因此需要在聚合物科学，纳米技术和大众传输方面具有独特的专业知识。该项目还将导致对支撑层结构如何影响原位聚合过程和产生膜的性能的基本了解。 PI和Co-Pi都被认为是FO的世界专家，非常适合完成这项拟议的工作。两者都有专门针对本提案中概述的任务定制的设施和专家。这个新兴的技术平台将为UConn的学生提供出色的教育工具。正向渗透是一个多步骤过程，依赖于多个单元操作。因此，我们将专门将前向渗透融合到化学工程盖石化高级设计课程中，为多个小组提供了争夺最佳设计配置的机会，该配置使用了最少的能源，并且资本成本最低。 OASYS将为UCONNEANGIONING学生提供实习计划，这将引起Oasys的兴趣，该计划将支持UConn的工程师的员工，并促进长期的学术工业合作伙伴关系。在21世纪，安全可持续的供水是人类在公共卫生方面面临的最艰巨的任务。我们必须通过使用像FO这样的可持续和负担得起的技术来治疗折衷的来源来增加现有的供水。这些问题比在发展中国家中更重要。因此，PI将与无国界工程师的UConn分会（EWB）合作开始一个独特的项目，以将埃塞俄比亚的商业FO系统安装为遥控水净化器和教学工具。这项努力将成为美国现有国际发展/高等教育机构（US-AID/HED）项目的一部分。