Progress 05/01/24 to 04/30/25
Outputs Target Audience:During this reporting period, our efforts primarily reached academic audiences, including scientists, engineers, and researchers in sustainable food waste valorization, electrochemical science and engineering, redox polymers and chemical engineering through presentations and publications. In addition, we engaged our industry collaboratorsin preliminary discussions about potential applications of the redox-ED system. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?1. To characterize the membranes, we received training in the X-ray laboratory on Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR). This is in addition to training already received in the first year on high-performance liquid chromatography (HPLC), ion chromatography (IC), and circular dichroism (CD). 2. In addition to the existing project team, we recruited and trained a new graduate researcher to work on organic acid recovery using the redox-ED system. The project remains engaged with now two graduate students, a postdoc, and an undergaduate. How have the results been disseminated to communities of interest?The project over the past year has yielded one published peer-reviewed paper, one submitted paper, and 5 conference presentations. The project was disseminated by the students in oral presentations at major conferences including the ACS, AIChE, and MRS conferences in 2024-2025 timeframe. What do you plan to do during the next reporting period to accomplish the goals?The next year of the project will focus on scaling up the redox-ED system to handle larger volumes of whey, moving us closer to industrially relevant applications. Specifically, we will investigate the effects of cell size, cell stacking, and electrode count on system productivity, energy efficiency, and membrane durability. These efforts will help provide insights into optimizing the redox-ED system for large-scale whey demineralization and implementing its real-world implementation. We also plan to extend the technologies for application in broader protein separation case scenarios.
Impacts What was accomplished under these goals?
Objective 1.Investigate various whey waste compositions (e.g., acid, sweet, salty whey) to screen and source whey proteins that are selectively separable for valorization. We analyzed skimmed whey sourced from our collaborators in Leprino, the dairy food and ingredient company. Our investigation comprised both laboratory analysis and nutritional analysis of demineralized whey. In the lab, protein content in the whey was quantified using high-performance liquid chromatography (HPLC) and salt levels were measured through ion chromatography (IC). In addition, protein structures were examined using circular dichroism to help us assess how our redox electrodialysis system impacted protein functionality. Since the key project centered on demineralizing whey proteins to enhance their application in dairy-based foods, we evaluated the nutritional contents of the demineralized whey produced using our redox electrodialysis system. We utilized the Nutrient Rich Foods (NRF) 9.3 index - a metric of the nutrient density in food based on regulatory frameworks and dietary guidance. This index considers nine recommended nutrients (protein, fiber, vitamins A, C, and E, calcium, iron, potassium, and magnesium) and three nutrients to limit (saturated fat, added sugar, and sodium). Our findings revealed that demineralized whey, particularly the 50% demineralized, retains a strong nutritional profile while offering a reduced mineral content. This makes it a valuable ingredient for formulating nutritionally balanced products. Objective 2.Develop electrochemically mediated flow system based on redox electrolyte for continuous and selective salt and protein separation of whey waste stream. Redox electrodialysis (redox-ED) is an emerging flow-based separation technology that utilizes redox reactions to drive ion removal from feed solutions, whey in our case. While promising, the commercialization of redox-ED has been hindered by its reliance on costly and fouling-prone ion exchange membranes (IEMs). To address these limitations, we explored the use of nanofiltration membranes (NF) as a cost-effective and energy-efficient alternative within the redox-ED system. Our approach involved integrating NF membranes into the redox-ED cell in place of conventional IEMs. We investigated the effects of membrane configuration - specifically, the number and placement of NFs - on key performance metrics, including demineralization efficiency, protein retention, and energy consumption. The most effective setup was identified as the NF-CEM-NF configuration, which combines nanofiltration membranes with a cation exchange membrane in the middle. This optimized configuration demonstrated high demineralization efficiency (up to 90%), excellent protein retention (over 95%), and reduced energy consumption compared to systems relying solely on IEMs. Furthermore, the system was validated using real skimmed whey from our collaborators in Leprino, achieving 50% demineralization while maintaining protein integrity and structure. Importantly, unlike anion exchange membranes (AEMs), the NF membranes showed no signs of fouling during operation. This suggests a potential for improved long-term membrane performance, reduced maintenance frequency, and lower overall system costs through extended membrane lifespan. Objective3.Synthesize and engineer green redox polymers to facilitate usage of nanofiltration membranes and minimize crossover and interactions with proteins. The water-soluble redox polymer synthesized in the first year was poly(ferrocenylpropylmethacrylamide-co-[2-(methacryloyloxy)ethyl]trimethylammonium chloride), P(FPMAm-co-METAC). The high molecular weight of the polymer enabled effective retention by the nanofiltration membranes. More recently, we optimized the copolymer composition to a 25:75 ratio, balancing sufficient ferrocene units to support the redox reaction while properly maintaining water solubility. Objective4.Technoeconomic analysis of the redox-ED system and evaluation of the multi-channel system for relevant food manufacturing samples from the dairy industry. A technoeconomic analysis was conducted for the redox-ED system utilizing the NF-CEM-NF membrane configuration. Replacing IEMs with NFs led to a 58% reduction in total membrane costs from $1,091 for an all-IEM setup to $459 for the NF-CEM-NF configuration. This cost reduction was as result of the significantly lower price of NFs, which are 85-90% cheaper than IEMs. As a result, the capital cost of the system decreased by 54%, and operating costs were reduced by 48%. Overall, the technoeconomic assessment confirmed that the NF-CEM-NF redox-ED system presents a cost-effective, energy-efficient, and high-performing solution for whey demineralization.
Publications
- Type:
Peer Reviewed Journal Articles
Status:
Published
Year Published:
2024
Citation:
N. Kim, A. Aguda, C. Kim, X. Su, ACS Energy Lett. 2024, 9, 8, 38873912
- Type:
Other Journal Articles
Status:
Under Review
Year Published:
2025
Citation:
A. Aguda, N. Kim, E.F. Harbut, J. Elbert, J. Li, R. Merrill, C. Kim, X. Su. Architecture design of Nanofiltration-based Redox Electrodialysis for Whey Protein Valorization
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2024
Citation:
N. Kim, J. Lee, J. Jeon, J. Elbert, X. Su. Electrochemical Recovery of Biomolecules in Redox-Mediated Electrodialysis Platform. 245th Electrochemical Society Meeting, San Francisco, California, May 26-30, 2024.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2024
Citation:
N. Kim, J. Elbert, X. Su. Electrochemical Separations Through Redox Polymer Design. 98th ACS Colloid and Surface Science Symposium, Seattle, Washington, June 23-26, 2024.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2024
Citation:
N. Kim, J. Elbert, X. Su. Advances in Redox-Electrodialysis for Desalination and Water Remediation. American Institute of Chemical Engineers, San Diego, October 27-30, 2024.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2024
Citation:
W. Oh, N. Kim, H. Kim, R. Mackie, X. Su, Nanostructured Thin-Film Composite Membranes for Redox Flow Electrochemical Separations. Materials Research Society Fall Meeting, Boston, Massachusetts, December. 1-6, 2024.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2025
Citation:
J. Elbert, N. Kim, X. Su. Redox-polymer electrodialysis: Energy efficient desalination and PFAS removal enabled by copolymer design. American Chemical Society (ACS) Spring 2025 Meeting & Expo, San Diego, California, March 23 27, 2025.
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Progress 05/01/23 to 04/30/24
Outputs Target Audience:The target audience for the work is the scientific community on bioseparations, food manufacturing, and polymer design. We are also targeting relevant industry in dairy manufacturing, as well as the general public for the extended outreach of the work. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?1. For whey and cell culture characterization, we were trained on high-performance liquid chromatography (HPLC), ionic chromatography (IC) and inductively coupled plasma - opticalemission spectrometry (ICP-OES). We also collaborated with the X-ray Laboratory on campus to conduct circular dichroism on whey proteins and proteins in cell culture media to investigate their stability. 2. We recruited and trained one undergraduate researcher on colorimetry, chronoamperometry and chronopotentiometry experiments. How have the results been disseminated to communities of interest?As of April 2024, we have two publications (one has been submitted and one is under preparation) and have submitted the abstract for one conference presentation Presentations A. Aguda, N. Kim, J. Elbert, X. Su. Valorization of Whey Proteins via Redox-Mediated Electrodialysis. Division of Agricultural and Food Chemistry at ACS Fall 2024, Denver, CO, United States (Submitted for Aug 2024) N. Kim, A. Aguda, J. Lee, J. Jeon, J. Elbert, X. Su. Advancements in Redox-Mediated Electrodialysis for Valorization of Biomolecules. F01 - Advances in Industrial Electrochemistry and Electrochemical Engineering at ECS PRiME 2024, Honolulu, HI, United States (Submitted for Oct 2024) Publications Lee, J., Huang, K., Knust, K., Kim, N., Oh, W., Fernandes, S. M., Hatz, S., Fennelly, C., Kong, H., Su, X., Recycling spent cell culture media through redox-mediated electrodialysis. (Submitted) Kim, N., Aguda, A., Kim, C., Su, X. Redox-Electrodialysis for Desalination, Environmental Remediation, and Resource Recovery. (Submitted) Aguda, A., Kim, N., Elbert, J., Su, X., Valorization of Whey Proteins using Nanofiltration Membranes. (In preparation) What do you plan to do during the next reporting period to accomplish the goals?1. Understand the impact of different operating conditions on the redox-ED and perate our flow system at industrially suitable conditions with whey sourced from Leprino 2. Conduct a preliminary technoeconomic analysis on our system and compare with existing technologies for whey purification 2. Expand on this research by applying our redox-ED system to valorize or separate other relevant agricultural components
Impacts What was accomplished under these goals?
Objective 1.Investigate various whey waste compositions (e.g., acid, sweet, salty whey) to screen and source whey proteins that are selectively separable for valorization. High performance liquid chromatography was used to characterize the proteins and organic acids present in sweet whey sourced from industrial cheese-manufacturing plant, Leprino. Circular dichroism was also used to assess and understand the stability and conformational changes of the proteins. Objective 2.Develop electrochemically mediated flow system based on redox electrolyte for continuous and selective salt and protein separation of whey waste stream. We developed a redox electrodialysis flow system with three independent channels (feed, accumulating and redox channels) separated by membranes. The feed channel contains the waste stream, which is demineralized under an applied voltage, thereby purifying, and concentrating the proteins. The ions migrate to and are concentrated in the accumulating channel while the redox channel contains the redox electrolyte which is continuously circulated to drive the system. The flow system was successfully utilized to demineralize whey waste and selectively segregate metabolic byproducts from cell culture media for protein purification. Redox-ED achieved >90% demineralization of synthetic whey solutions and cell culture media was also demineralized up to 80% while preserving the proteins and their structure. Objective3.Synthesize and engineer green redox polymers to facilitate usage of nanofiltration membranes and minimize crossover and interactions with proteins. We synthesized a water-soluble redox copolymer containing ferrocene as the redox couple - poly(ferrocenylpropylmethacrylamide-co-[2-(methacryloyloxy)ethyl]trimethylammonium chloride), P(FPMAm-co-METAC). The macromolecular structure of the copolymer enables the usage of nanofiltration membranes in our redox-ED system. We also optimized the polymer design based on desired electrochemical and material properties. Objective4.Technoeconomic analysis of the redox-ED system and evaluation of the multi-channel system for relevant food manufacturing samples from the dairy industry. The feasibility of redox-ED for the refinement of proteins in cell culture media was investigated. Our redox-ED system decreased the material usage efficiency by up to 34% indicating an environmentally and economically beneficial system.
Publications
- Type:
Conference Papers and Presentations
Status:
Submitted
Year Published:
2024
Citation:
A. Aguda, N. Kim, J. Elbert, X. Su. Valorization of Whey Proteins via Redox-Mediated Electrodialysis. Division of Agricultural and Food Chemistry at ACS Fall 2024, Denver, CO, United States
- Type:
Conference Papers and Presentations
Status:
Submitted
Year Published:
2024
Citation:
N. Kim, A. Aguda, J. Lee, J. Jeon, J. Elbert, X. Su. Advancements in Redox-Mediated Electrodialysis for Valorization of Biomolecules. F01 - Advances in Industrial Electrochemistry and Electrochemical Engineering at ECS PRiME 2024, Honolulu, HI, United States (Submitted for Oct 2024)
- Type:
Journal Articles
Status:
Awaiting Publication
Year Published:
2024
Citation:
Kim, N., Aguda, A., Kim, C., Su, X. Redox-Electrodialysis for Desalination, Environmental Remediation, and Resource Recovery. (Submitted)
- Type:
Journal Articles
Status:
Other
Year Published:
2024
Citation:
Lee, J., Huang, K., Knust, K., Kim, N., Oh, W., Fernandes, S. M., Hatz, S., Fennelly, C., Kong, H., Su, X. Recycling spent cell culture media through redox-mediated electrodialysis. (In Preparation)
- Type:
Journal Articles
Status:
Other
Year Published:
2024
Citation:
Aguda, A., Kim, N., Elbert, J., Su, X. Valorization of Whey Proteins using Nanofiltration Membranes. (In preparation)
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