PFAS adsorbent and catalyst. Image Credit: framergy Inc.
The challenge of PFAS contamination (sometimes publicly known as PFOS, PFOA, or GenX contamination) of drinking water and its risk to public health will be featured in a leading Hollywood film being released this November.
PFAS exposure can be dangerous to humans, possibly causing liver damage, kidney cancer, and developmental issues in children. Over the years, the substance can build up in animals and humans, which heightens the risk.
PFAS, or Per- and polyfluoroalkyl substances are what the US Food and Drug Administration has termed ‘Forever Chemicals’ because of their endurance in the human body.
They were the preferred choice among consumer product chemists because of their hydrophobic chains, which enable the material to produce a non-stick coating and move water away.
The substance can be discovered in the cooking non-stick pans, office furniture, and fast food packaging. It is also popular in firefighting foams, which has resulted in extensive contamination of water sources where these foams are utilized.
There has not been much planning on what to do with the contaminant, even though there are methods to collect PFAS.
Chemical engineers are producing several techniques to totally destroy PFAS that are collected, but they need off-site processes which either require burying the conjoined absorbant or PFAS material as a new form of permanent waste or are highly energy-intensive.
Temperatures of 1000 °C (~1800 °F) are needed for the latter method, and not many adsorbents utilized to collect the chemical can survive that degree of heat. The cost to the environment is still high in both of the methods.
Metal Organic Frameworks
Enter MOFs: Metal Organic Frameworks are crystalline 3D structures with an extraordinary internal surface area that transfers into an incredible ability to absorb molecules.
A method to produce defects in MOFs made at Rice University has already demonstrated that the materials can absorb over two times more than the industrial standard, activated carbon.
Destruction of PFAS
The first MOF company, framergy, Inc., was funded by the US Environmental Protection Agency (EPA), under the Small Business Innovation Research (SBIR) program, in May 2019 to investigate PFAS destruction.
In collaboration with Texas A&M University, the research looks at how PFAS are captured by MOFs. The MOF and guest PFAS molecules are then subjected to ultraviolet light.
Image Credit: framergy Inc.
Scientists at framergy are utilizing ARYSORB™ T125, a titanium MOF that is structurally similar to the UiO-66 variety employed by the Rice scientists.
ARYSORB™ T125 is based on MIL-125-NH2, which was first invented in 2008 by Christian Serre and Gerard Ferey of the Centre National de la Recherche Scientifique (CNRS).
In ARYSORB™ T125, titanium oxo clusters are periodically arranged and divided through the use of organic linkers, which results in a large and highly accessible surface area.
The titanium nodes can then perform as a photocatalyst on the guest PFAS molecule, something impossible in UiO-66. This material is exclusively licensed to framergy, along with all alternative titanium-based MOFs known, by CNRS, and is available at commercial scale from the organization and at Strem.com.
Destruction tests were carried out with 500 ppm perfluorooctane sulfonate (PFOS) in an aqueous solution with 1% triethanolamine as a sacrificial reductant. The 250 mL solution was incubated in a customized Ace Glass photochemical reactor, under a 12-watt UV photo-chemical lamp which ran down the column. Conversion of PFOS to less harmful organic material was visibly confirmed by Fluorine-19 nuclear magnetic resonance spectroscopy, after which an Agilent liquid-chromatography-mass spectrometer showed three distinct peaks for C8 down to C3 compounds with different fluoride content.
This definitely proved that PFAS species originating in water can be collected and degraded by ARYSORB™ T125 into smaller substances that are less dangerous, with the use of readily available UV light.
framergy is vigorously scaling the technology for commercialization through the EPA’s SBIR program where PFAS are being focused on by the agency at the same time through, "the most comprehensive cross-agency action plan for a chemical of concern ever undertaken by the agency," as stated by Andrew Wheeler, Director.
Phase I Program
The next stage will be to finish Phase I of the program and submit an application for the Phase II award.
EPA’s SBIR Program is pleased to support small businesses such as framergy that are working to bring their innovative ideas to the market to solve tough environmental issues such as treating PFAS in water.
April Richards, SBIR Program Manager, EPA
This development solves the main challenges in the war on PFAS.
Our company’s titanium metal organic frameworks have proven to not only capture dangerous PFAS in water systems, but to break them down to be less bio-accumulative with the help of the sun.
Ray Ozdemir, Chief Operating Officer, framergy, Inc.
The organization is also utilizing the materials for unique personal care usage, for example, pollutant scavengers and sunblocks on the skin.
This information has been sourced, reviewed and adapted from materials provided by framergy, Inc.
For more information on this source, please visit framergy, Inc.