Collaborative Research: Elucidating the Coupling of Inorganic Scaling and Organic Fouling in Reverse Osmosis Desalination: An Integrated Experimental and Computational Approach

气候变化和人为污染导致地球仪许多区域的淡水资源日益稀缺。在美国，干旱和半干旱地区的缺水对粮食生产、能源生产、生态和人类健康构成威胁。海水淡化技术可以从海水、含盐地下水和废水中收集净化水，是应对水资源短缺的重要工具。反渗透（RO）是一种商业化的脱盐技术，其依赖于淡水在施加的压力下通过致密膜的渗透。尽管其广泛的应用，RO过程是脆弱的性能衰减所造成的污染，或不必要的物质沉积在膜表面上。本研究旨在了解两种常见的RO结垢类型之间的相互作用：由有机物吸附引起的有机结垢和由矿物沉淀引起的无机结垢。研究人员将实验测量与计算机模拟相结合，以揭示有机污垢和无机结垢物质在RO脱盐过程中如何相互作用。研究人员将在乔治华盛顿大学和科罗拉多州立大学领导与研究相关的公众参与和外展活动。将为来自华盛顿，华盛顿特区当地社区的学生举办以水可持续性为主题的讲习班，和科罗拉多。反渗透（RO）是目前最先进的海水淡化技术，由于其卓越的能源效率。虽然无机结垢物和有机结垢物的存在被认为极大地限制了反渗透的性能，但无机结垢和有机结垢的综合影响还没有得到很好的理解。本研究的主要目的是阐明膜-水界面上无机结垢物与有机结垢物的相互作用。研究人员将研究薄膜复合聚酰胺膜在RO中无机结垢和有机结垢的组合下的性能，并揭示有机结垢物影响矿物结垢的机制。先进的建模方法将被用来模拟成核动力学的矿物鳞片在有机污垢的存在下，阐明在分子水平上控制矿物成核的有机污垢的作用。在结垢和结垢的组合下，还将检查防污膜的性能，以告知膜设计。该项目将通过（i）阐明组合结垢和结垢对RO膜性能的影响，这无法通过单独结垢或结垢的现有知识来预测，（ii）推进对有机污垢如何调节工程膜表面的矿物成核和生长的机械理解，和（iii）证明旨在减轻有机污染的功能性膜表面将如何响应组合的结垢和污染。该项目的教育和推广方面将把研究成果纳入本科生和研究生课程材料，在当地社区引入以水可持续性为主题的研讨会，并促进代表性不足的学生参与研究。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

Climate change and anthropogenic pollution are contributing to the increasing scarcity of freshwater resources in many regions around the globe. In the United States, water stress in arid and semi-arid regions poses a threat to food production, energy generation, and ecological and human health. Desalination technologies can harvest purified water from seawater, saline groundwater, and wastewater and are an important tool to combat water scarcity. Reverse osmosis (RO) is a commercial desalination technology that relies on the permeation of freshwater through a dense membrane under an applied pressure. Despite its widespread application, the RO process is vulnerable to performance decay caused by fouling, or the unwanted deposition of substances on the membrane surface. This research aims to understand the interplay between two common types of RO fouling: organic fouling caused by the adsorption of organic matter and inorganic scaling caused by the precipitation of minerals. The investigators will integrate experimental measurements with computational simulations to reveal how organic foulants and inorganic scale-forming substances interact with each other during RO desalination. The investigators will lead research-related public engagement and outreach activities at both George Washington University and Colorado State University. Water sustainability-themed workshops will be hosted for students from local communities in Washington, D.C., and Colorado. Reverse osmosis (RO) is currently the state-of-the-art desalination technology due to its exceptional energy efficiency. Although the existence of inorganic scalants and organic foulants is known to greatly constrain the performance of RO, the combined effects of inorganic scaling and organic fouling are not well understood. The overarching goal of this research project is to elucidate the interactions of inorganic scalants with organic foulants at the membrane-water interface. The investigators will study the performance of thin-film composite polyamide membranes under combined inorganic scaling and organic fouling in RO and unravel the mechanisms by which organic foulants impact mineral scaling. Advanced modeling approaches will be employed to simulate nucleation kinetics of mineral scales in the presence of organic foulants, elucidating the role of organic foulants in controlling mineral nucleation at the molecular level. The performance of anti-fouling membranes under combined scaling and fouling will also be examined to inform membrane design. The project will close a fundamental knowledge gap by (i) elucidating the effects of combined scaling and fouling on RO membrane performance, which cannot be predicted by existing knowledge of individual scaling or fouling, (ii) advancing mechanistic understanding of how organic foulants regulate mineral nucleation and growth at engineered membrane surfaces, and (iii) demonstrating how functional membrane surfaces that are intended to mitigate organic fouling will respond to combined scaling and fouling. Educational and outreach aspects of the project will incorporate research findings into undergraduate and graduate course materials, introduce water sustainability-themed workshops in local communities, and promote the participation of underrepresented students in research.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.