NSF-BSF: Electrified Membrane System for Chemical-Free Nitrogen Recovery from Nitrate Contaminated Water

氨是最重要的工业商品之一，用于各种应用，包括制药，塑料，造纸和化肥生产。在全球每年生产的1.76亿吨氨中，约85%用于化肥生产。此外，由于运输和储存的方便性和安全性，氨作为一种有前途的燃料最近受到了相当大的关注。目前，氨的商业生产是通过依赖天然气作为原料的能源密集型工艺进行的。近期，由于疫情影响及其他地缘政治因素，氨生产中断，导致氨成本上升及供应链不确定性。同时，氮，氨的中心元素，以各种化学形式普遍存在于城市，农业和工业废水中。这些含氮废物的来源可以为氨生产提供可靠和廉价的氮源（每年约24亿公斤）。目前的废水处理工艺消耗能量来去除废氮化合物并将其转化为氮气，而没有任何回收机制。此外，尽管饮用水和废水处理工艺普遍存在，但在美国仍有超过4000万人无法获得经水处理的水，而是主要依赖可能含有硝酸盐和其他含氧阴离子污染物的私人地下水威尔斯井。即使在公共供水系统中，硝酸盐也是美国最常报告的水质违规行为之一，可能危及数百万人的健康。因此，新泽西理工学院和以色列本-古里安大学的研究人员之间的这项国际合作项目旨在解决与从废物中回收氮并将其转化为氨有关的知识空白，同时使用创新的带电膜工艺处理废水。总的来说，项目的最终目标是探索一种可持续的途径，从含硝酸盐的废水中产生氨，并减轻硝酸盐污染和工业氨生产的压力。为了实现这一目标，这个国际合作者团队将采用多方面的方法，包括电化学膜过滤研究，计算化学和数值模拟，以揭示硝酸盐与催化剂和氨与膜界面的分子水平相互作用，并描绘反应物种的动力学映射（例如，硝酸盐或氨）。预期项目成果包括：（1）研究一套新型催化剂涂层疏水气体交换膜，该膜能够有效还原硝酸盐并同时转移氨气;（2）同步阴极和阳极反应，以还原硝酸盐并原位产酸捕获氨气;（3）通过计算模拟和密度泛函理论分析，阐明了三相膜界面的电化学催化和传质机理;（4）确定废水基质如溶液pH和共存物质对阴极膜操作稳定性的影响;（5）阐明阴极/阳极表面上潜在的结垢机理和预防策略。该项目将促进美国和以色列研究人员之间的合作，并为两个合作机构的研究生和本科生提供良好的研究和教育培训机会。受地下水硝酸盐影响的不同新泽西社区的公平和有意义的参与将通过社区外展活动来实现，以及来自花园州路易斯·斯托克斯少数民族参与联盟的代表性不足的学生（GS-LSAMP）将参与绿色电化学和催化纳米技术研究。该奖项反映了NSF的法定使命，并通过使用基金会的学术价值和更广泛的影响审查标准。

Ammonia, one of the most important industrial commodities, is used for diverse applications including pharmaceutics, plastics, paper, and fertilizer production. Of the 176 million tons of annually produced ammonia worldwide, about 85% is used for fertilizer production. Furthermore, ammonia has recently received considerable attention as a promising fuel due to convenience and safety in transportation and storage. Currently, ammonia is commercially produced by an energy-intensive process that relies on natural gas as a feedstock. Recently, ammonia production was interrupted due to the pandemic impacts and other geopolitical factors, resulting in an increase in ammonia cost and supply chain uncertainties. Meanwhile, nitrogen, the central element of ammonia, is prevalent in municipal, agricultural, and industrial wastewaters in various chemical forms. These sources of nitrogen-containing waste could provide a reliable and cheap nitrogen source (around 2.4 billion kg per year) for ammonia production. Current wastewater treatment processes consume energy to remove waste nitrogen compounds and convert them into nitrogen gas without any recovery mechanisms. Additionally, despite the prevalence of drinking and wastewater treatment processes, there are still over 40 million people in the US that do not have access to municipally treated water, instead relying mostly on private groundwater wells that may contain nitrate and other oxyanion pollutants. Even in public water systems, nitrate is among the most commonly reported water quality violations in the US and could compromise the health of millions of people. Therefore, this international collaborative project between researchers at the New Jersey Institute of Technology and Ben-Gurion University in Israel aims to address the knowledge gaps related to recovering nitrogen from waste and converting it into ammonia while treating wastewater using an innovative electrified membrane process. Overall, the ultimate project goal is to explore a sustainable pathway to generate ammonia from nitrate-containing wastewater and alleviate the stresses from nitrate pollution and industrial ammonia production. To achieve this goal, this team of international collaborators will employ multifaceted approaches including electrochemical membrane filtration studies, computational chemistry, and numerical simulations to unravel the molecular-level interactions of nitrate with catalysts and ammonia with membrane interfaces and to delineate the dynamics mapping of reaction species (e.g., nitrate or ammonia) on cathodic membrane surfaces. The expected project outcomes include (1) examination of a suite of novel catalyst-coated hydrophobic gas exchange membranes that enable efficient nitrate reduction and simultaneous ammonia gas transfer; (2) synchronization of cathodic and anodic reactions for nitrate reduction and in situ acid production to trap ammonia; (3) clarification of mechanisms of electrochemical catalysis and mass transfer in this three-phase membrane interface via computational simulations and density functional theory analyses; (4) determination of the effects of wastewater matrices such as solution pH and co-existing substances on the stability of cathodic membrane operations; and (5) elucidation of potential scaling mechanisms and preventive strategies on cathodic/anodic surfaces. This project will foster a collaboration between the US and Israeli researchers and provide excellent research and educational training opportunities to graduate and undergraduate students of the two collaborating institutions. A fair and meaningful involvement of diverse New Jersey communities affected by groundwater nitrate will be accomplished through community outreach activities, and underrepresented students from the Garden State Louis Stokes Alliance for Minority Participation (GS-LSAMP) will be involved in the green electrochemical chemistry and catalysis nanotechnology 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.