ERASE-PFAS: Coupling electrified separation and reaction approaches for short-chain PFAS remediation in semiconductor manufacturing

全氟和多氟烷基物质(PFAS)是一类人工合成的化学物质，由于其持久性、稳定性和对自然环境退化过程的抵抗力，通常被称为永远的化学物质。在过去的二十年里，在地表水系统(如湖泊和河流)和地下蓄水层中检测到的全氟辛烷磺酸越来越多，这些地下蓄水层是全美许多社区的饮用水来源。虽然日益加强的监管措施导致许多长链全氟辛烷磺酸(全氟辛烷磺酸)被逐步淘汰，但短链全氟辛烷磺酸(例如碳原子不超过六个的全氟烷基磺酸)正被积极用作半导体工业等行业的替代品。在半导体制造中，短链PFAS化合物被用作各种单元工艺/应用的功能材料，包括光致抗蚀剂、减反射涂层、润湿剂、腐蚀剂和冷却液。半导体工厂产生大量废水，短链全氟辛烷磺酸的浓度从10-100ppt(毫克/L)到20ppm(毫克/L)不等。该项目的总体目标是设计、评估和优化一种集成的电吸附和电催化工艺，该工艺可以选择性地从半导体废水中提取和降解短链PFAS。该项目的成功完成将通过开发和实施更有效的技术来处理和修复受短链全氟辛烷磺酸污染的工业废水和饮用水水源，从而造福社会。还将通过学生教育和培训，包括对伊利诺伊大学厄巴纳-香槟分校的两名研究生进行辅导，为社会带来更多好处。由于半导体废水通常由复杂的高浊度混合物组成，其中含有悬浮固体(如二氧化硅和纳米Ce2+)、有毒金属离子(如铜)和溶解的有机污染物(如络合配体和表面活性剂)，现有的商业技术(如离子交换、颗粒活性碳吸附和反渗透)不能有效地从半导体废水中提取和破坏短链PFAS。该项目的一个主要目标是推进开发下一代集成电化学分离和反应系统所需的基础科学和工程知识，该系统可以选择性地捕获、释放和销毁受污染的水中的短链全氟辛烷磺酸，重点是半导体行业的废水。这项研究的具体目标是：(1)设计、合成和表征具有高选择性的短链PFAS的电活性聚合物吸附剂；(2)评估短链PFAS在气液和固液界面的反应性，以推进用于PFAS降解的电化学反应器的设计；以及(3)评估短链PFAS通过等离子体和掺硼金刚石电极的耦合电吸附和电化学降解所造成的破坏。该项目的成功完成有可能通过产生新材料和基础知识来指导设计、开发和实施更有效的技术来处理和补救全氟辛烷磺酸污染废水，从而产生变革性的影响。为了实现该项目的教育和推广目标，首席调查员(PI)建议利用伊利诺伊大学香槟分校(UIUC)现有的计划，如青年科学与工程夏令营，为K-12学生开发和提供教育活动，包括水净化和等离子工程研讨会。此外，PIs还计划利用UIUC Merrill学者计划和伊利诺伊州本科生学者计划从代表不足的群体中招募和指导本科生参与项目研究活动。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Per- and polyfluoroalkyl substances (PFAS) are a group of man-made chemicals that are commonly referred to as “forever chemicals” due to their persistence, stability, and resistance to natural environmental degradation processes. During the last two decades, PFAS have been increasingly detected in surface water systems (e.g., lakes and rivers) and groundwater aquifers which serve as sources of drinking water for many communities throughout the United States. While increasing regulatory measures have led to many long-chain PFAS such perfluoro octane sulfonic acid (PFOS) being phased out, short-chain PFAS (e.g., perfluoroalkane sulfonic acids with six or fewer carbon atoms) are actively being used as alternatives in industries such as the semiconductor industry. In semiconductor manufacturing, short chain PFAS compounds are utilized as functional materials in various unit processes/applications including photoresists, antireflective coatings, wetting agents, etchants, and coolants. Semiconductor fabs generate significant amounts of wastewater with variable concentrations for short chain PFAS ranging from 10-100 ppt (nanograms/L) to 20 ppm (milligrams/L). The overarching goal of this project is to design, evaluate, and optimize an integrated electrosorption and electrocatalytic process that can selectively extract and degrade short chains PFAS from semiconductor wastewater. The successful completion of this project will benefit society through the development and implementation of more efficient technologies to treat and remediate industrial wastewater and drinking water sources contaminated by short chain PFAS. Additional benefits to society will be achieved through student education and training including the mentoring of two graduate students at the University of Illinois at Urbana-Champaign. Because semiconductor wastewater streams typically consist of complex and high turbidity mixtures that contain suspended solids (e.g., silica and cerium nanoparticles), toxic metal ions (e.g., copper) and dissolved organic pollutants (e.g., complexing ligands and surfactants), established and commercial technologies (e.g., ion exchange, sorption with granular activated carbon, and reverse osmosis) cannot effectively extract and destroy short chain PFAS from semiconductor wastewater. A major goal of this project is to advance the fundamental science and engineering knowledge required to develop the next-generation of integrated electrochemical separation and reaction systems that can selectively capture, release, and destroy short-chain PFAS in contaminated water with a focus on wastewater streams from the semiconductor industry. The specific objectives of the research are to (1) design, synthesize, and characterize electroactive polymer sorbents with high selectivity for short-chain PFAS; (2) evaluate the reactivity of short-chain PFAS at gas-liquid and solid-liquid interfaces to advance the design of electrochemical reactors for PFAS degradation; and (3) evaluate the destruction of short-chain PFAS via coupled electrosorption and electrochemical degradation using plasma and boron-doped, diamond-based electrodes. The successful completion of this project has the potential for transformative impact through the generation of new materials and fundamental knowledge to guide the design, development, and implementation of more efficient technologies to treat and remediate PFAS contaminated wastewater. To implement the educational and outreach goals of this project, the Principal Investigators (PIs) propose to leverage existing programs at the University of Illinois at Urbana-Champaign (UIUC) such as the Youth in Science and Engineering camps to develop and deliver educational activities for K-12 students including workshops on both water purification and plasma engineering. In addition, the PIs also plan to leverage the UIUC Merrill Scholars Program and the Illinois Undergraduate Scholars Program to recruit and mentor undergraduate students from underrepresented groups to work on the project research activities.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.