Pseudocapacitive and Intercalation Compounds for Water Desalination: Surface Chemistry, Electrode Structure and Foulant Tolerance

提案编号：1403826主要研究者：Mauter，Meagan机构名称：梅吉-梅隆大学标题：水脱盐的准电容和嵌入化合物：表面化学、电极结构和污垢耐受性NSF接收日期：10/29/2013世界上只有0.03%的水适合人类使用，对清洁水的需求是当前的关切，今后只会变得更加紧迫。虽然大部分注意力都集中在将海水淡化为饮用水，但有效淡化微咸水/盐水（约0.5至30 ppt盐）的能力将是水回收的重要选择。如果成功的话，应该有积极的经济和水资源的影响咸水淡化，这影响了大多数在陆地上的水淡化努力在农业，城市用水，和废水处理，其中电容脱盐过程的高回收率是特别有吸引力的，后处理，或盐水处置，使低回收膜为基础的系统昂贵。在教育影响方面，PI和co-PI将开发一门以水和能源为重点的入门课程，整合工程和社会社会政治观点（PI和co-PI在工程和公共政策系联合任命）。此外，主要研究者和共同主要研究者将通过参与匹兹堡水经济网络和国家科学院/国家环境工程学院科学和工程大使计划，将拟议的研究纳入教学和推广活动。电容去离子（CDI），即多孔电极捕获带电物质，然后将其释放到废水中，是一种有前途的咸水淡化方法;但是该技术受到阳离子/阴离子去除循环的低效率和电极结垢倾向的限制。该提议试图用表现出伪电容和/或快速嵌入特性的新的复合电极结构来替代现有的碳电极结构，其中材料从弱法拉第反应中快速捕获和释放离子。从电荷积累的角度来看，这些电极将能够进入明显更密集的电化学反应，从而允许更薄、更有效的电极结构，其在结垢条件下也不太容易受到性能降低的影响。PI将首先选择可行的候选材料，并在相关的赝电容去离子（PDI）环境中评估其界面电荷和离子转移机制。然后，他们将表征PDI颗粒和电极宏观/介观结构对PDI反应所观察到的性能的影响，然后在模型胶体污垢蚂蚁的存在下评估PDI表面的性能，因为胶体和细菌的电极污垢严重降低了传统CDI电极的离子吸附能力。

PROPOSAL NO.: 1403826PRINCIPAL INVESTIGATOR: Mauter, MeaganINSTITUTION NAME: Carnegie-Mellon UniversityTITLE: Pseudocapacitive and Intercalation Compounds for Water Desalination: Surface Chemistry, Electrode Structure and Foulant ToleranceNSF RECEIVE DATE: 10/29/2013With only 0.03% of the world's water is suitable potable water for human use, the need for clean water is a current concern that can only become more urgent in the future. While much of the attention has been on desalination of seawater into potable water, the ability to desalinate brackish/briny water (~0.5 to 30 ppt salt) efficiently would be a significant option for water reclamation. If successful, there should be positive economic and water-resource impact of desalination of brackish water, which affects most the in-land water desalination efforts in agricultural, municipal water, and wastewater treatment, where the high recovery rates of capacitive desalination processes are particularly attractive and where post-treatment, or brine disposal, makes low-recovery membrane-based systems expensive. In terms of educational impact, the PI and co-PI will develop an introductory course that focuses on water and energy, integrating engineering and social sociopolitical perspectives (both PI and co-PI hold joint appointments in the Department of Engineering and Public Policy). In addition, the PI and co-PI will incorporate the proposed research into teaching and outreach through participating in the Pittsburgh Water Economy Network and the NAS/NAE Science and Engineering Ambassador Program.Capacitive de-ionization (CDI), whereby charged species are captured by porous electrodes and then released into a waste stream, is a promising approach for desalination of brackish water; but the technology is limited by the low efficiency of the cation/anion removal cycle and by the tendency of the electrodes to foul. This proposal seeks to replace existing carbon electrode structures with new composite electrode structures that exhibit pseudo-capacitive and/or fast intercalation properties, where the materials quickly capture and release ions from weak faradic reactions. These electrodes will be able to access electrochemical reactions that are significantly denser, from a charge accumulation perspective, thereby allowing for thinner, more efficient electrode structures that are also less susceptible to diminished performance under fouled conditions. The PIs will first select viable candidate materials and evaluate their interfacial charge and ion transfer mechanisms in a relevant pseudocapacitive deionization (PDI) environment. They will then characterize the impact of PDI particle and electrode macro/meso-structures on the performance observed for PDI reactions, followed by evaluations of the performance of PDI surfaces in the presence of model colloidal foul ants, since electrode fouling by colloids and bacteria severely diminishes the ion adsorption capacity of conventional CDI electrodes.