NSF-BSF: Ion transport and selectivity in salt-rejecting membranes operating at elevated salinities and pressures

NSF-BSF：在高盐度和压力下运行的脱盐膜中的离子传输和选择性

• 批准号: 2136835
• 负责人: Anthony Straub
• 金额: $ 45万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2136835&HistoricalAwards=false
• 关键词: NSF; BSF; Ion; transport; selectivity

Extremely salty water is produced in enormous quantities as waste from brackish water and seawater desalination, and oil and gas production. Purifying these wastewaters is a significant priority because it (1) advances human welfare and prosperity by increasing water supplies and (2) protects public health by reducing the discharge of potentially harmful wastewaters. Despite the importance of purifying very salty waters, current purification processes require substantial amounts of thermal energy or heat. This research project will investigate how to use polymer membranes to treat extremely salty water sources. Such membrane treatments can use less than one-tenth of the energy compared to conventional thermal systems. Novel experiments and molecular simulations will be used to better understand how polymer membranes perform under the high salt and high-pressure conditions needed for purifying this type of wastewater. The knowledge gained by these experiments will make it possible to develop polymer membranes specifically for high-salt wastewaters. Students researchers will collaborate directly with international partners, including travelling to Israel to improve cultural and scientific exchange. Undergraduate education will be improved through the creation of an innovative “Engineered Solutions to Water Scarcity” module where collaborators serve as guest lecturers. The interdisciplinary nature of this project will enhance mentorship of underrepresented and first-generation university undergraduate students through the CU Boulder BOLD Center by motivating interest in chemical engineering, environmental engineering, and separations science. Outreach to high-school students will be accomplished by developing and implementing classroom lessons, hands-on activities, and a short video that will be made publicly available on global water scarcity challenges and engineered solutions. The research project will elucidate mechanisms governing ion transport in membranes during high-salinity brine treatment and create a framework for designing membranes with improved water-salt selectivity by tuning chemistry and structure. The central hypothesis is that elevated salinity and pressure cause significant variations in the intrinsic ion transport properties through polymer deswelling, electrostatic charge shielding, membrane compaction, and fundamental changes in ionic hydration properties. The impact of extreme salinity and pressure conditions on these phenomena will be comprehensively investigated using advanced transport characterization techniques. In particular, transition state theory will be applied to membrane permeability to elucidate molecular-level enthalpy- and entropy-related effects that occur during ion transport and stem from extreme salinity and pressure conditions. Such molecular-level effects will be further explored using molecular simulations of ion transport through the membrane. Based on the insights gained, increasing water-salt selectivity of membranes at elevated salinity and pressure using tailored charge, hydrophobicity, and crosslinking density will be explored. Ultimately, the results of this project will reveal the effect of high salinity and pressure on molecular transport under the extreme confinement of reverse osmosis and nanofiltration membrane pores, improve the fundamental understanding of ion transport in polymers, and create design recommendations that will aid in the development of membrane-based processes for high-salinity brine treatment.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

咸水和海水脱盐以及石油和天然气生产中的废物产生了极高的咸水。净化这些废物是一个重要的优先事项，因为（1）（1）通过增加供水来提高人类福利和繁荣，（2）通过减少潜在有害废水的排放来保护公共卫生。尽管重要的是纯化非常咸的水，但当前的净化过程仍需要大量的热能或热量。该研究项目将研究如何使用聚合物膜来治疗极其咸的水源。与传统的热系统相比，这种膜处理可以使用不到十分之一的能量。新型实验和分子模拟将用于更好地了解在净化此类废水所需的高盐和高压条件下聚合物膜的性能。这些实验获得的知识将使专门用于高盐废水的聚合物膜成为可能。学生的研究人员将直接与国际合作伙伴合作，包括前往以色列改善文化和科学交流。通过创建创新的“水短缺解决方案”模块，将改善本科教育，其中合作者担任客座讲师。该项目的跨学科性质将通过Cu Boulder Bold中心通过激励化学工程，环境工程和分离科学的兴趣来增强代表性不足和第一代大学本科生的位归。通过开发和实施课堂课程，动手活动以及简短的视频将在全球水缺乏挑战和工程解决方案上公开可用，可以通过开发和实施课堂课程和简短的视频来实现向高中生的宣传。该研究项目将阐明高盐度盐水处理过程中管理膜中离子传输的机制，并通过调整化学和结构来设计提高水盐选择性的机制框架。中心假设是，盐度升高和压力通过聚合物解散，静电电荷屏蔽，膜压实以及离子水合特性的根本变化而导致内在离子传输性能的显着变化。极端盐度和压力条件对这些现象的影响将通过先进的运输特征技术进行全面研究。特别是，过渡状态理论将应用于膜的通透性，以阐明离子转运过程中发生的分子水平焓和熵相关的作用，并源于极端盐度和压力条件。通过通过膜传输的分子模拟，将进一步探索这种分子水平的作用。基于获得的见解，将探索使用定制电荷，疏水性和交联密度的盐度和压力下膜的水盐选择性的提高。最终，该项目的结果将揭示高盐和压力对分子运输的影响，在反渗透和纳米过滤的膜孔中的极端限制下，改善了对聚合物离子运输的基本了解，并创建设计建议，并创建有助于通过高度易于培养的质量降低的奖励效果。基金会的智力优点和更广泛的影响评论标准。