Grantee Research Project Results
Final Report: Green and Sustainable Water Purification Membranes
EPA Grant Number: SU839961Title: Green and Sustainable Water Purification Membranes
Investigators: Poler, Jordan C , Sahu, Abhispa , Rollins, Rachel , Jones, Anna , Oliver, Sydney , Reid, Christopher
Institution: University of North Carolina at Charlotte
EPA Project Officer: Page, Angela
Phase: I
Project Period: October 1, 2019 through September 30, 2020 (Extended to September 30, 2021)
Project Amount: $24,867
RFA: P3 Awards: A National Student Design Competition Focusing on People, Prosperity and the Planet (2019) RFA Text | Recipients Lists
Research Category: Heavy Metal Contamination of Soil/Water , P3 Awards , P3 Challenge Area - Safe and Sustainable Water Resources , Urban Air Toxics
Objective:
This project proposes to develop a green, sustainable and eco-friendly membrane system that removes chemicals that persist following traditional water treatment. To achieve this, a cellulose nanoscale anion-exchange resin will be developed. Since cellulose nanofibers are abundant and inexpensive, this proposal, if successful, will provide affordable water purification solutions to rural communities that have high concentrations of contaminants found in water systems.
Summary/Accomplishments (Outputs/Outcomes):
(Objective 1) Synthesis, purification and optimization of ion exchange functionalized cellulose nanofiber materials and membranes. This objective has been met and the proposed water purification materials were synthesized, purified, and optimized to the best of the model chemistry would allow.
(Objective 2) Processing and Characterization of Cellulose NanoResin Materials. This objective was met.
(Objective 3) Outreach, teaching, and training. This objective was met. Due to the pandemic, we were not allowed to travel to regional high schools as we proposed. These outreach activities were done virtually.
(Objective 4) Point-of-use water purifiers. This objective was met. It took longer than expected due to the pandemic lockdown, but we exceeded the metrics of the initial proposed objective.
(Objective 1) The hydrodynamic diameter of pristine cellulose nanofibers measured using dynamic light scattering (DLS) zetasizer was in the range of ~250 nm. After purification, the successful debundling of -COO-Na+ modified cellulose nanofibers were confirmed using DLS with a hydrodynamic diameter of 24 nm. The oxidation of cellulose was confirmed using Fourier transform Infrared Spectroscopy with a strong peak around 1575.85 cm-1 due to presence of -COO-Na+ group Zeta potential of cellouronic acid solution was measured to be -28 mV. The amide reaction and functionalization of allyl amine hydrochloride was confirmed using Fourier Transform Infrared Spectroscopy (FTIR) where we observed shifting of C=O stretch at 1640.01 cm-1, appearance of N-H in plane vibrations at 1534.6 cm-1 and C-N stretch at 1429.6 cm-1. Zeta potential of amide modified cellulose nanofibers were measured to be -19 mV. To confirm allyl amine hydrochloride is covalent attached to cellulosic scaffold, no IR peaks in the filtrate were detected which confirms there is no presence of any residual unreacted components. Zeta potential of poly(vbTMAC) functionalized cellulose nanofibers was measured to be +17.2 mV which confirmed the covalent attachment of polyelectrolyte to cellulose nanofibers. Our proposed polymer functionalization chemistry used a two step process that included an amide bond formation. This chemistry worked, however the yield was lower that expected. Moreover, the method used an expensive catalyst that could limit the economic viability of these materials synthesized in the phase I project.
(Objective 2) Cellulose NanoResins were successfully purified using brine/dialysis and brine/centrifugation methods. Purified materials were tested for loading capacity. Adsorptive oading, qe, measured from incubation experiment was measured to be 12.6 mg-C NaFL/G polymer functionalized cellulose. Preliminary analysis of adsorption isotherm was performed to understand the adsorption behavior.
(Objective 3) We recruited four project participants. Two undergraduates from UNC Charlotte and two High School students from local magnet school, the “Charlotte Engineering Early College” (CEEC). All four participants were trained in laboratory safety and chemical hygiene. The participants were active in the laboratory up to mid-March. The lab was shut down due to the COVID pandemic lockdown. Before the shut down the participants and the investigators took one of the planned filed trips to a wastewater treatment facility. The participants spent several hours on a guided tour and did a reflexive analysis of their interaction with the plant operator/manager. The students continued their participation virtually, they attended weekly group meeting, they were introduced to the literature, they were asked to analyze published papers related to this project and they all wrote progress reports. We were not able to do any additional out-reach to nearby watershed communities due to the pandemic. It is unlikely we will be able to do significant outreach until the pandemic has cleared and it is safe to interact with the general community.
(Objective 4) This was the last planned objective of the Phase I project. Due to the lockdown, only the PI and the graduate student was available in the lab to finish this part of the project. Since the initial submission of the final report, we have completed the outputs for objective 4.
1. Testing adsorption capacity, adsorption isotherms and % removal of contaminants using CNR
2. Regeneratability studies using CNR
The last part of the objective was very difficult to reach during the project because of the pandemic.
3. Fabrication to 47 mm membrane holders for breakthrough studies and long-term testing. Since then we have made large area membranes and integrated them into a POU module. The area of this module is actually much larger than our stated objective in phase I. We made a 38 cm2 membranes and we proposed a 17.3 cm2 membrane.
This research project encompassed the P3 ideology of seeking sustainable solutions with respect to environmental protection, strengthening social upliftment, economic growth and fostering overall growth. The project strived to work towards environment quality improvement. Our research work employed green synthesis and design for formulating ecofriendly cellulose based nanoresins (CNR). Our research incorporated the principles of green chemistry. We have created water purification membranes, that remove the pervasive, persistent, and bioaccumulating hydrophilic contaminants from water that are deleterious to human health. Our water purification membranes are stable and regeneratable without significant degradation or fouling. These next generation water purification systems are new promising materials to enhance water quality, promote healthy habitats and preserve the environment. This proposal shaped the research and educational background of the student participants who worked on this project. Students were taught connections between smart technologies with sustainability. In order to encourage more students to pursue advanced and sustainable research in the water sector we worked with faculties and students at the Charlotte Engineering Early College High School. Students were exposed to concepts and technology so as to understand global environmental issues and how to develop tools to deal with them constructively.
Journal Articles:
No journal articles submitted with this report: View all 3 publications for this projectSupplemental Keywords:
Cellulose, Water Purification, Membrane, Ion Exchange, NanomaterialRelevant Websites:
Progress and Final Reports:
Original AbstractP3 Phase II:
Restoring Public Confidence in Drinking Water Safety - Education, Engagement, and New Sustainable Technology | 2022 Progress 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.