High Performance Water Desalination Using Propagating Ion Concentration Shock Waves

美国国家科学基金会颁发的化学和生物分离项目奖支持斯坦福大学Juan Santiago教授开发高效海水和咸淡水脱盐（离子去除）设备的工作。目前，美国面临着人口增长和淡水资源减少的同时，因此海水淡化对于实现可持续水资源管理将变得越来越重要。然而，目前的海水淡化方法存在能源和/或基础设施成本高的问题。为了开发降低这些成本的新方法，圣地亚哥的团队正在研究由浓度极化产生的离子浓度冲击波。当电场在称为离子交换膜的特殊膜上施加时，就会产生浓度极化。这种浓度极化描述了在膜的一侧产生一个离子浓度富集的区域，以及在膜的另一侧产生一个离子浓度耗尽（脱盐）的区域。感兴趣的波是连接离子富集和耗尽生长区域的尖锐的移动界面。圣地亚哥小组将专注于进行控制实验和开发关键现象的模型，这些模型将用于开发高效设备。该小组将开发脱盐设备的原型，产生少量的、可测试的淡化水。该小组将招收本科生，并将这项研究的材料纳入工程课程。

This NSF award by the Chemical and Biological Separations program supports work by Professor Juan Santiago at Stanford University to develop highly efficient sea and brackish water desalination (ion removal) devices. Currently, the US faces simultaneous population growth and a decline in freshwater resources, so that desalination will become increasingly important towards realizing sustainable water management. However, current desalination methods suffer from high energy and/or infrastructure costs. In an effort to develop new methods which reduce these costs, Santiago's group is researching ion concentration shock waves created by concentration polarization. Concentration polarization arises when an electric field is applied across specialized membranes called ion exchange membranes. This concentration polarization describes the creation of a region of enriched ion concentration on one side of the membrane, and the associated creation of a region of depleted (desalinated) ion concentration on the opposite side of the membrane. The waves of interest are sharp, moving interfaces which bound growing regions of ion enrichment and depletion. The Santiago group will focus on performing controlled experiments and developing models of key phenomena, which will be utilized to develop highly efficient devices. The group will develop prototype desalination devices which generate small, test-amounts of desalinated water. The group will engage undergraduate students and incorporate material from this research into engineering curriculum courses.