Hanyang University Researchers Reveal How PFAS Chain Length Influences Environmental Fate and Water Treatment

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Jun 29, 2026, 08:32 ET

Short-chain PFAS move farther in water and resist treatment, offering a new roadmap for safer drinking water

SEOUL, South Korea, June 29, 2026 /PRNewswire/ -- Per- and polyfluoroalkyl substances (PFAS), often referred to as "forever chemicals," are among the most persistent contaminants found in water systems worldwide. Their strong carbon–fluorine bonds make them highly resistant to degradation, allowing them to remain in the environment for long periods. While PFAS are often treated as a single group of pollutants, growing evidence suggests that differences in their molecular structure can significantly influence both their environmental behavior and their response to treatment technologies.

PFAS, often called "forever chemicals," do not all behave the same way in water. The length of a PFAS molecule's fluorinated carbon chain can influence how far it travels, where it accumulates, and how easily it can be removed. Understanding these differences could help improve water treatment technologies and support efforts to reduce PFAS contamination in drinking water and the environment.

In a new review, a team of researchers led by Professor Eilhann E. Kwon from Hanyang University, South Korea, examined how the length of a PFAS molecule's fluorinated carbon chain affects its environmental fate and treatment outcomes. By synthesizing findings from environmental, laboratory, and modeling studies, the researchers sought to identify patterns that could help improve PFAS monitoring, remediation, and water treatment strategies. Their findings were made available online on 5 March 2026 and have been published in Volume 9 of the journal npj Clean Water.

"PFAS, often referred to as 'forever chemicals,' should not be viewed as a single uniform group," said Prof. Kwon. "The length of the fluorinated carbon chain controls behavior of PFAS in water."

PFAS have become a growing concern because they persist in the environment and are difficult to remove once released. However, thousands of PFAS compounds exist, making it challenging to predict their behavior and identify the most effective treatment approaches.

To address this challenge, the researchers reviewed studies comparing short-chain and long-chain PFAS across environmental settings and treatment technologies. The review evaluated physicochemical properties, environmental transport, bioaccumulation, removal efficiency in non-destructive treatment processes, and degradation efficiency in destructive treatment systems. Technologies examined included activated carbon adsorption, ion exchange, membrane filtration, and advanced destruction methods designed to break down PFAS molecules.

The analysis revealed clear differences between short-chain and long-chain PFAS. Long-chain compounds tend to bind more strongly to sediments, organic matter, and biological tissues, increasing their potential for environmental accumulation. At the same time, these stronger interactions generally make long-chain PFAS easier to capture using conventional treatment materials. In contrast, short-chain PFAS remain more soluble in water and can travel farther through rivers, groundwater, and drinking-water systems, making them more difficult to remove and degrade.

These findings are particularly important because many short-chain PFAS are increasingly being used as replacements for older long-chain compounds. Understanding chain-length-dependent behavior could help utilities and remediation projects select more effective treatment approaches.

"Over the next 5 to 10 years, this knowledge can support more predictive and customized water treatment systems that can capture and destroy a broader range of PFAS, including the short-chain compounds," said first author Dr Youn-Jun Lee.

As regulations continue to evolve and new PFAS compounds emerge, treatment systems may need to move beyond one-size-fits-all approaches and become more tailored to molecular characteristics.

"Our work suggests that treatment strategies should be designed based on the molecular structure of PFAS, especially chain length," said Dr Lee.

Although treatment performance can vary depending on local conditions, the findings highlight chain length as a useful framework for understanding PFAS behavior and improving future treatment strategies.

Reference

Title of original paper: Perfluoroalkyl chain-length-dependent environmental fate and treatment outcomes of PFAS in water
Journal: npj Clean Water
DOI: https://www.nature.com/articles/s41545-026-00568-5#citeas

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SOURCE Hanyang University