Grantee Research Project Results
Final Report: A Novel, Nanostructured,Metal-OrganicFrameworks-BasedPretreatmentTechnology for the Remediationof PFAS inIndustrial Wastewater
EPA Contract Number: 68HERD19C0012Title: A Novel, Nanostructured,Metal-OrganicFrameworks-BasedPretreatmentTechnology for the Remediationof PFAS inIndustrial Wastewater
Investigators: Ozdemir, Osman K
Small Business: Framergy, Inc
EPA Contact: Richards, April
Phase: I
Project Period: May 1, 2019 through October 31, 2019
Project Amount: $100,000
RFA: Small Business Innovation Research (SBIR) - Phase I (2019) RFA Text | Recipients Lists
Research Category: Small Business Innovation Research (SBIR) Phase I (2018) , Small Business Innovation Research (SBIR) , SBIR - Water Quality , Small Business Innovation Research (SBIR): Phase 1 (2019)
Description:
Per- and Polyfluoroalkyl substances, otherwise known as PFAS, are a large group of chemicals including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). These chemicals have a large variety of uses globally. Remediation of PFAS has gained importance due to their environmental persistence and toxicity, especially in water. Water treatment methods must combine multiple strategies to be effective, as PFAS are commonly found in complex mixtures in the environment. To address the growing environmental concerns around PFAS contamination, novel remediation methods, combing the strengths of multiple strategies are needed urgently.
In the Phase I activity, framergy, Inc., in collaboration with Texas A&M University (TAMU), has shown the feasibility of a novel water pretreatment technology based on nanostructured metal-organic frameworks (MOFs) for the effective removal of PFAS by leveraging their highly selective adsorption and easily activated photocatalytic properties. At the heart of the technology is framergy's innovative, chemically stable, titanium-based MOFs which can be tailored for the selective capture and photocatalytic breakdown of PFAS under UV/sunlight. It eliminates the frequent changeout of leading adsorbent alternatives and reaction retention time limitations of conventional chemical reduction technologies.
Summary/Accomplishments (Outputs/Outcomes):
Preliminary tests showed that perfluorooctane (C8) can be broken down to shorter chain (C4 and C3) fluorinated species. Similarly, tests with PFOS showed shorter chain (C7 and C3) fluorinated species. Over the course of this project the objective has been to drive these photocatalytic reactions to mineralization by first generating shorter chain species for less toxicity. This is the main reason why the main PFSA and PFCA manufacturers have phased out the production of these species and replaced them with shorter chain alternatives. These replacements are generally less toxic and are excreted more rapidly than the longer chain compounds, health-based drinking water levels for them will likely be higher than for the longer chain PFAS. Another advantage of this phased approach which entails this first photocatalytic cleavage step is it makes it possible for the Ti-MOFs to adsorb these smaller chains into its pores and give MOFs the extra retention time to continue the photocatalytic mineralization of shorter chain PFAS.
The conducted research has evaluated photocatalytically active metal-organic frameworks (MOFs) for the capture and breakdown of PFAS in water. This was accomplished by first, scavenging and storing PFAS by adsorption and then initiating reductive reactions to breakdown the adsorbed PFAS within MOFs for effective and prolonged remediation. The purpose of this research has been to evaluate the feasibility of different MOFs synthesized from high valent Ti4+ clusters for the highest capture and degradation of PFAS in water.
The research findings showed that framergy, in collaboration with Texas A&M University, has successfully proved the feasibility of a PFAS remediation technology based on metal-organic frameworks (MOFs), which can adsorb and photocatalytically degrade these toxic compounds in water. The candidate materials identified by framergy have been the first group of MOFs to photocatalytically degrade PFAS; although adsorptive removal of PFAS has been shown in the past, none of the MOFs published to date could initiate reductive reactions to breakdown the adsorbed PFAS within their framework until this study. An environmental technology verification report will be prepared once this regenerable and mobile treatment system design is developed, piloted and tested for the remediation of PFAS in industrial wastewater.
Conclusions:
The Phase I results show that framergy can not only photocatalytically degrade PFAS in water but also systematically increase the photocatalytic degradation efficiency. The dark vs. irradiation tests clearly showed that PFAS degradation in water continued under irradiation, indicating continuous breakdown of PFAS within MOFs. The analytical tests conducted showed that only the tested PFAS (PFOA) was present in the treated water samples, which also verified that the photodegradation byproducts were held inside the MOFs, preventing the release of shorter-chain species during photocatalytic breakdown of PFOA.
The United States could soon see stricter regulations of PFAS, as the knowledge surrounding them is rapidly evolving. This new technology will work dynamically to help regulators achieve safer conditions for PFOA and PFOS in drinking water. Besides water treatment applications, the proposed photocatalytically active Ti-MOFs technology can be utilized for water splitting and chemical conversion of CO2 to generate feedstock materials for energy generation and polymers production. With activity under the visible spectrum, Ti-MOFs can be used for water splitting to generate hydrogen, this is an opportunity which is significantly less energy intensive compared to electrolysis used for electrochemical water splitting.
SBIR Phase II:
A Novel, Nanostructured, Metal-Organic Frameworks-Based Pretreatment Technology for the Remediation of PFAS in Industrial Wastewater | 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.