Grantee Research Project Results
Final Report: Restoring Public Confidence in Drinking Water Safety - Education, Engagement, and New Sustainable Technology
EPA Grant Number: SV840383Title: Restoring Public Confidence in Drinking Water Safety - Education, Engagement, and New Sustainable Technology
Investigators: Poler, Jordan C
Institution: University of North Carolina at Charlotte
EPA Project Officer: Aja, Hayley
Phase: II
Project Period: June 1, 2022 through May 31, 2024
Project Amount: $99,999
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2022) Recipients Lists
Research Category: Drinking Water , Drinking Water, Disinfection Byproducts , Clean Water , Human Health , Water , Green Chemistry , P3 Awards , PFAS Treatment , P3 Challenge Area - Safe and Sustainable Water Resources
Objective:
Objective 1: Synthesis and Optimization of Functionalized Cellulose
Objective 2: Novel Esterification to Cellulose Nanofibrils
Objective 3: Characterization of Functionalized Cellulose Membranes
Objective 4: Point-of-Use (POU) Water Purifiers
Almost all of the objectives proposed were completed. Objective 4 was partially completed. The parallel regeneration and reuse of multiple POU devices was not completed. The Cost Analysis of Return – Replacement Market was not completed.
The two cohorts of student participants generated many valuable outputs related to engaging people about water quality and about entrepreneurial activities related to water purification technology. Students were given pre- and post- engagement surveys for various community outreach activities. The most effective were the engagements at the Lee Dukes water treatment and lab facility and at the Irwin Creek wastewater treatment and lab facility run by the Charlotte water authority. 60 customer discover interviews led the student groups to several conclusions. The customer discovery interviews revealed that there is a significant interest in investing in water purification technology, especially among individuals who are environmentally and health-conscious. The key findings indicate that potential customers, particularly parents, homeowners, and those living in urban areas, are willing to pay for a more efficient and higher-cost water filtration system if it is easy to use, produces better-tasting water, and offers superior protection against contaminants like heavy metals and pollutants compared to their current filters. The participants showed an inclination towards solutions that are sustainable and reduce plastic use, aligning with a desire for environmentally friendly options.
The customer archetype identified includes parents, typically mid-20s and older, who are financially stable, health-conscious, and motivated to provide clean, safe drinking water for their families. The primary pain points involve concerns about personal and family health, maintenance costs, and accessibility. The value proposition that resonated most was a filter that offers cleaner, better-tasting water, prevents exposure to harmful contaminants, and supports sustainability. Future efforts in customer discovery should focus on engaging a broader range of participants and asking more specific questions about their motivations for investing in water purification technology.
Summary/Accomplishments (Outputs/Outcomes):
The study focuses on the green synthesis of cellulose graft copolymers, referred to as cellulose nanoresins (CNR), for use in anion exchange water purification. The researchers successfully synthesized the CNR by grafting poly(vinyl benzyl trimethyl ammonium chloride) onto TEMPO-oxidized nanocellulose via acid-catalyzed Fischer-Speier esterification. The CNR demonstrated an impressive adsorption capacity of 26.8 mg of adsorbate per gram, with rapid adsorption kinetics achieving equilibrium in under 30 seconds. When tested as thin-film membranes, CNR maintained over 99% adsorption efficiency over 40 regeneration cycles, indicating excellent reusability and stability. The films were also effective at removing perfluorooctane sulfonate (PFOS) from water to below the detection limit of 100 ppt, making them suitable for real-world water purification applications. The cellulose base material and water-based synthesis method emphasize green chemistry principles, ensuring a sustainable and low-cost production process.
However, some challenges were identified, such as the need for precise control of the grafting process to optimize the functionalization of the cellulose nanofibrils, and the incomplete esterification reaction due to steric constraints. Quality assurance results confirmed the high purity and consistency of the CNR, as evidenced by dynamic light scattering, zeta potential measurements, and conductometric titration, which validated the percent functionalization and particle size. The regenerated films exhibited consistent performance across cycles, with negligible loss in adsorption efficiency, confirming the durability and stability of the CNR. Overall, the study concludes that the CNR represents an effective and environmentally sustainable solution for removing harmful anions from water, with high potential for practical water purification applications.
Several commercialization challenges could arise in bringing the cellulose nanoresin (CNR) technology to market (1) While the laboratory synthesis of CNR is efficient and employs green chemistry principles, scaling up the process to an industrial level may present challenges. Maintaining consistent quality, uniform functionalization, and high adsorption efficiency in large-scale production could be technically demanding. The Fischer-Speier esterification and TEMPO-mediated oxidation steps, in particular, may need optimization to ensure they remain cost-effective and environmentally friendly at a commercial scale. (2) Despite the renewable nature of cellulose and the aqueous synthesis process, the cost of raw materials, reagents (such as TEMPO), and equipment required for large-scale production might still be relatively high compared to conventional ion-exchange resins. Ensuring that CNR production remains economically viable compared to existing water purification materials will be crucial for commercialization. (3) CNR-based water purification membranes must meet stringent regulatory standards for safety and effectiveness, especially for applications in drinking water treatment. Extensive testing and certification may be required to demonstrate that the materials do not leach any harmful substances and maintain performance over long-term use, which can be time-consuming and costly. (4) Introducing a new water purification technology often requires significant market education, particularly when competing with well-established filtration systems. Demonstrating the advantages of CNR, such as its green synthesis, high adsorption efficiency, and regenerability, to potential customers, including municipalities, industrial users, and water treatment companies, will be essential but may take time and effort.
Addressing these challenges through process optimization, cost reduction strategies, comprehensive regulatory testing, and targeted marketing will be critical to successfully commercializing CNR technology for water purification applications.
Conclusions:
The study presents the development of cellulose graft copolymers, termed cellulose nanoresin (CNR), for anion exchange in water purification. The technical effectiveness of the CNRs is demonstrated through their ability to achieve rapid equilibrium adsorption in less than 30 seconds and a high removal efficiency of over 99% across 40 regeneration cycles. These properties indicate that the CNR films exhibit high adsorption capacity, are stable over multiple uses, and maintain consistent performance, which makes them suitable for practical water purification applications.
Economically, the process of synthesizing the CNR uses green chemistry principles, including aqueous functionalization and renewable cellulose as the base material. This approach not only reduces the environmental impact but also potentially lowers production costs compared to conventional synthetic resins that rely on petrochemical sources. Additionally, the CNR’s regenerability over numerous cycles further enhances its cost-effectiveness, reducing the need for frequent replacements.
The research offers significant contributions to understanding and addressing environmental challenges, particularly water contamination by harmful anions such as perfluorooctane sulfonate (PFOS). The study demonstrates the CNR’s ability to reduce PFOS concentrations to below detectable levels, showcasing its potential to tackle contaminants of emerging concern in drinking water. The CNR’s biodegradable nature and use of non-toxic, water-based synthesis methods also minimize secondary pollution, making it an environmentally friendly alternative.
Overall, this work advances sustainable water purification technologies, providing a promising solution that is both effective and eco-friendly, with clear benefits for human health by improving access to cleaner water sources.
Journal Articles on this Report : 2 Displayed | Download in RIS Format
| Other project views: | All 24 publications | 3 publications in selected types | All 3 journal articles |
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Schmal SC, Dosi R, Fessler A, Kwiatkowski C, Sahu A, Poler JC. Green synthesis of cellulose graft copolymers for anion exchange water purification. Cellulose. 2023;30(17):11055-69. |
SV840383 (Final) |
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Sahu A, Poler JC. Removal and degradation of dyes from textile industry wastewater:Benchmarking recent advancements, toxicity assessment and cost analysis of treatment processes. Journal of Environmental Chemical Engineering. 2024:113754. |
SV840383 (Final) |
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Progress and Final Reports:
Original AbstractP3 Phase I:
Green and Sustainable Water Purification Membranes | 2020 Progress Report | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.