Per- and polyfluoroalkyl substances, commonly known as PFAS, are widely recognized as challenging environmental contaminants due to their persistence, toxicity, and widespread occurrence in water systems. Their environmental stability and broad use have created an urgent need for improved detection, remediation, and treatment strategies.
At the same time, PFAS can be difficult to remove efficiently and sustainably, particularly when considering sorbent performance, regeneration, and treatment cost. Several PFAS treatment approaches rely on adsorption-based technologies, where PFAS molecules are captured by a sorbent material. But for these technologies to become more sustainable, it is not enough to simply identify materials that adsorb PFAS. It is also important to understand how PFAS interact with sorbent surfaces, how strongly they bind, how selective the interactions are, and whether adsorption is reversible under conditions relevant to regeneration. This is where surface and interface analysis can help.
Why adsorption-based PFAS treatment depends on surface interactions
For adsorption-based PFAS removal, performance is largely governed by interfacial processes. When PFAS molecules encounter a sorbent, membrane, coating, or sensor surface, their adsorption behavior depends on a combination of molecular structure, surface chemistry, charge, hydrophobicity, and surrounding water chemistry.
These interactions determine key treatment-relevant questions, such as:
- How quickly do PFAS adsorb to a surface?
- Which surface chemistries promote stronger or more selective binding?
- Can captured PFAS be released again under regeneration-relevant conditions?
- How can sorbents be designed to combine high uptake with efficient desorption or regeneration potential?
Answering these questions benefits from techniques that can follow molecular-scale events at the solid–liquid interface in real time.
QCM-D as a tool for mechanistic PFAS studies
Quartz Crystal Microbalance with Dissipation monitoring, QCM-D, is a surface-sensitive technique that tracks adsorption and desorption processes as they happen. By measuring changes in frequency and dissipation, QCM-D provides information about mass uptake at the surface and, through dissipation monitoring, changes in the mechanical or viscoelastic character of the interfacial layer.
For PFAS research, this makes QCM-D especially valuable. It can be used to study how PFAS interact with engineered sorbent surfaces, how different surface modifications influence adsorption, and how binding behavior changes between PFAS compounds. The resulting data can help reveal mechanisms behind PFAS capture and support the rational design of next-generation treatment materials.
From mechanistic insight to sustainable treatment
Granular activated carbon is widely used for PFAS removal, but regeneration can be energy-intensive and may limit long-term sustainability. Developing more sustainable PFAS treatment therefore requires new sorbent concepts, improved surface design, and a better understanding of adsorption and desorption behavior relevant to regeneration.
At the University of Arizona, Prof. Vasiliki Karanikola and her team are addressing PFAS challenges through several complementary research directions: assessing contamination in Arizona, developing real-time PFAS sensors, designing cost-effective sorbent-based treatment technologies, and building QSPR-based modeling tools to guide future material design.
In their work, they use QCM-D to investigate PFAS–sorbent interactions at the molecular scale. These mechanistic studies provide insight into adsorption behavior, surface modification effects, and the reversibility of PFAS–surface interactions — information that is relevant to sorbent regeneration. Together, these insights can support the development of more effective and sustainable PFAS treatment strategies.
Join the webinar June 10 to learn more
To explore this topic in more detail, we are delighted to welcome Dr. Vasiliki Karanikola, Associate Professor of Chemical and Environmental Engineering at the University of Arizona, to share insights from her work on sustainable PFAS treatment and QCM-D mechanistic studies.
In this webinar, Dr. Karanikola will discuss the challenge of sustainable PFAS treatment and how mechanistic QCM-D studies can help inform the design of improved sorbents and treatment strategies.
In this webinar, you will learn about:
- The challenges of developing sustainable PFAS treatment technologies
- The limitations of granular activated carbon, particularly around regeneration
- How novel sorbents and surface modifications can improve PFAS adsorption and support regeneration
- How QCM-D helps reveal PFAS–sorbent interactions at the molecular scale
- How mechanistic insight can inform next-generation PFAS treatment strategies
