NSF-BSF Application: Selective Electrosorption for Boron Removal and Recovery from Seawater

农业灌溉是美国用水量最大的领域，约占美国清洁用水的80%。海水淡化是一种抗旱技术，可以解决农业和其他用途日益增长的用水需求。海水反渗透（SWRO）是目前市面上最好的海水淡化技术。但淡化后的海水除硼能力有限，不能直接用于灌溉。这是由于商业SWRO膜的硼保留能力的限制。当硼含量超过0.3 mg/L的水用于灌溉时，硼会对植物生长产生不利影响，损害苹果、柑橘、葡萄和其他作物。因此，商业SWRO工厂必须使用额外的净化步骤将硼浓度降低到可接受的浓度。这大大增加了能源消耗和使用淡化水用于农业的成本。提出的研究将通过开发基于电吸附的新型选择性分离技术来解决与硼去除相关的低效率问题。这项新技术将是无化学物质，节能，并能够回收高纯度的硼流有益的用途。该项目的成功完成将推动下一代可持续SWRO工厂的发展，对社会具有巨大的潜在效益。该项目将为耶鲁大学的研究生和本科生提供研究培训，从而进一步造福社会。此外，该研究员将通过参与耶鲁大学K-12的外展活动，促进多样性，并加强科学和工程领域代表性不足群体的参与。SWRO海水淡化的一个关键和未解决的挑战是产生适合灌溉的渗透水流，而不需要额外和昂贵的净化来去除植物有毒元素，如硼。该项目的总体目标是开发一种创新的流动式电吸附工艺，用于海水淡化中硼的去除和回收。为了实现这一目标，PI建议围绕以下任务进行综合实验和建模项目：1)使用硼螯合树脂作为构建块制造超选择性正极（阳极）；2)制备的选择性除硼回收电极的性能测试；3)阐明选择性硼电吸附机理；4)电化学反应对电极长期稳定性和硼选择性的影响评估；5) sro -电吸附联合工艺的能耗和硼选择性评价与建模。这项提议的工作将是第一个研究使用无化学物质方法从海水中选择性去除和回收硼的工作。这项研究的成功完成有可能通过开发一种更节能和可持续的从SWRO工厂去除和回收硼的工艺来改变海水淡化。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。

Agricultural irrigation is the largest user of water in the United States, accounting for approximately 80 percent of the Nation’s clean water consumption. Seawater desalination is a drought-proof technology that can address growing demands for water in agriculture and other uses. At present, seawater reverse osmosis (SWRO) is the best available commercially available desalination technology. However, the desalinated seawater cannot be used directly in irrigation due to the limited ability to remove boron. This results from limitations on the boron retention capability of commercial SWRO membranes. Boron adversely impacts plant growth and damages apple, citrus, grapes, and other crops when water containing more than 0.3 mg/L of boron is used in irrigation. Thus, commercial SWRO plants must use an additional purification step to reduce boron concentration to acceptable concentrations. This greatly increases the energy consumption and costs of using desalinated water for agriculture. The proposed research will address the inefficiencies associated with boron removal through the development of a novel selective separation technology based on electrosorption. This new technology will be chemical-free, energy efficient, and capable of recovering a high purity boron stream for beneficial uses. Successful completion of this project will advance the development of the next generation of sustainable SWRO plants, with great potential benefit to society. The project will fruther benefit society by providing research training to graduate and undergraduate students at Yale University. Also, the investigator will promote diversity and enhance the involvement of under-represented groups in science and engineering through engagement in Yale's K-12 outreach activities. A critical and unresolved challenge in SWRO desalination is to produce a permeate water stream suitable for irrigation without additional and costly purification to remove plant-toxic elements such as boron. The overall goal of this project is to develop an innovative flow-through electrosorption process for boron removal and recovery in seawater desalination. To achieve this goal, the PI proposes to carry out an integrated experimental and modeling project structured around the following tasks: 1) fabrication of an ultra-selective positive electrode (anode) using boron-chelating resins as building blocks; 2) performance testing of the fabricated electrodes for selective boron removal and recovery; 3) elucidation of the mechanisms underlying selective boron electrosorption; 4) assessment of the impact of electrochemical reactions on the long-term stability and boron selectivity of the electrodes; and 5) evaluation and modeling of the energy consumption and boron selectivity of the combined SWRO-electrosorption process. The proposed work would be the first to study boron-selective removal and recovery from seawater using a chemical-free method. The successful completion of this research has potential to transform desalination through the development of a more energy efficient and sustainable boron removal and recovery process from SWRO plants.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.