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正在造成全球许多地区淡水资源日益短缺。在美国，干旱和半干旱地区的水资源紧张对粮食生产、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获得纯净水，是解决水资源短缺的重要工具。反渗透（RO）是一种商业脱盐技术，它依赖于淡水在施加压力下通过致密膜的渗透。尽管应用广泛，但反渗透工艺容易受到污染或有害物质沉积在膜表面引起的性能下降的影响。本研究旨在了解两种常见的反渗透结垢之间的相互作用：由有机物吸附引起的有机结垢和由矿物质沉淀引起的无机结垢。研究人员将把实验测量与计算模拟结合起来，揭示有机污染物和无机结垢物质在反渗透海水淡化过程中是如何相互作用的。调查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推广活动。将为来自华盛顿特区和科罗拉多州当地社区的学生举办以水可持续发展为主题的研讨会。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。虽然无机结垢剂和有机污垢的存在极大地限制了反渗透性能，但无机结垢剂和有机污垢的联合作用尚未得到很好的理解。本研究项目的总体目标是阐明无机垢与有机污染物在膜-水界面的相互作用。研究人员将研究反渗透中无机结垢和有机结垢复合作用下薄膜复合聚酰胺膜的性能，并揭示有机污染物影响矿物结垢的机理。将采用先进的建模方法模拟有机污染物存在下矿物尺度的成核动力学，阐明有机污染物在分子水平上控制矿物成核的作用。在结垢和结垢联合作用下，抗污膜的性能也将被检验，以指导膜的设计。该项目将通过(i)阐明组合结垢和结垢对反渗透膜性能的影响，这是现有的单个结垢或结垢知识无法预测的；（ii）推进对有机污染物如何调节工程膜表面矿物成核和生长的机制理解，从而缩小基本知识差距。（iii）演示旨在减轻有机污染的功能性膜表面如何对结垢和污染的组合做出反应。该项目的教育和推广方面将把研究成果纳入本科和研究生课程材料，在当地社区引入以水可持续性为主题的讲习班，并促进代表性不足的学生参与研究。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.