PFAS treatment and disposal technologies

Synthesis

Disclaimer: The content of this publication is based on the state of knowledge and the regulatory framework in force at the time of publication of the documents.

Context

PFAS constitute a large family of more than 12,000 synthetic organic compounds produced by humans. Their molecular structures and physicochemical properties vary considerably. However, these compounds share the common characteristic of having at least one carbon atom fully substituted with fluorine atoms—that is, a perfluoromethyl group ( CF₃) or a perfluoromethylene group ( CF₂ ) (OECD 2021). The carbon–fluorine bond gives them remarkable chemical and thermal stability, which has led to their widespread use in various industrial applications (medical, automotive, electronics, etc.), consumer products (food packaging, textiles, etc.), and firefighting applications.

From the early 2000s onward, scientific advances highlighted potential impacts on health and the environment, triggering public concern and regulatory attention. Observed effects relate to all stages of the PFAS life cycle, from emissions by producers or users to their disposal as waste or their dispersion into different environmental matrices. Due to their stability, PFAS are highly resistant to degradation and persistent in the environment. The diversity of compounds leads to varied and complex behaviours in environmental media, depending on many factors such as the type of PFAS, the presence of co contaminants, and the properties of the receiving environment. In addition, the presence of precursors and their possible transformation into terminal PFAS adds another layer of complexity when assessing PFAS behaviour and fate.

PFAS are thus ubiquitous in the environment, but the level of knowledge in France remains highly variable depending on the matrix studied. Available data relate mainly to liquid media (surface water and groundwater), in connection with recent regulations, notably the June 2023 decree targeting 20 substances under the Water Framework Directive (WFD). Monitoring actions are carried out on incinerators and releases from regulated facilities (ICPE), but they focus on a limited number of compounds. Conversely, wastewater treatment plant (WWTP) sludge has been subject to only partial characterisation, and data on soils and gaseous media remain very limited. This heterogeneity hinders an overall understanding of the environmental cycle of PFAS and complicates the implementation of coherent management strategies.

This limited knowledge results from several factors. The regulatory framework is still underdeveloped, with only a few existing reference values—mainly for drinking water—thus limiting monitoring obligations in other matrices. Toxicological reference values are still insufficient and restricted to a few compounds, making health risk assessment difficult. Ongoing development of sampling methods (e.g., for gaseous matrices), high analytical costs, and the expertise required to interpret data hinder wider implementation. For example, the use of the integrative parameter AOF (Adsorbable Organic Fluorine) can be difficult to interpret, particularly when measured concentrations exceed the list of 20 PFAS or the full set of analyzable PFAS (roughly 60).

As a result, site owners remain reluctant to carry out sampling campaigns—particularly on soils and groundwater—due to concerns about obtaining data that are difficult to interpret from a regulatory standpoint.

Objective of the study

The ultimate objective of the study is to identify treatment solutions tailored to each type of emission. To achieve this, the strategy consisted in analysing the life cycle of PFAS—from their behaviour in the environment and within existing treatment systems, to their behaviour and potential destruction in technologies specifically designed for this class of contaminants. This approach considers the diversity of PFAS compounds through:

• The analysis of their physicochemical and thermodynamic properties to explain their persistence and their behaviour in different matrices;
• The study of their interactions with environmental media as a function of parameters such as pH, moisture content, organic matter, etc.;
• A review of the available technologies and their respective efficiency;
• The use of PFAS properties to model treatment performance by extrapolation, in response to limited data that often focus on a narrow subset of compounds.

By providing achievable levels of treatment efficiency, this study can serve as a decision support tool to help authorities prioritise the streams to be treated and to define regulatory objectives.

Organisation of the study

The study is structured around three main components. The first component aims to identify the sources, locations, and matrices in which treatment can be applied. This identification step, essential for the proper progression of the study, considers the different compounds and families of compounds encountered.

The second component examines the transport and fate of PFAS across various natural and anthropogenic transformation processes. This part includes both the theoretical understanding of PFAS stability and a broader analysis of the different interactions between these substances and the characteristics of environmental matrices (water, air, and soil), in relation to their physicochemical properties. This component provides the basis for understanding how the compounds behave to better inform treatment strategies.

The third component inventories and analyses the different treatment technologies according to the media and matrices involved. The purpose of this section is to provide the most comprehensive overview possible of the treatments available to date. As technologies evolve rapidly, the information presented is likely to change.

Main results

In this study, 36 PFAS compounds were selected to represent the diversity and ubiquity of this family in the environment. The selection was based on their occurrence in emission sources, the variety of their physicochemical properties, their prevalence in environmental matrices, and the availability of analytical data. Given the highly variable behaviour of PFAS—linked to the diversity of their structures, the limited knowledge available for certain compounds, and analytical uncertainties—it appears that their classification cannot be restricted to the length of the fluorinated chain alone.

A graphical representation based on these properties makes it possible to visualize their theoretical environmental behaviour (mobility, phase distribution) and to compare them with well known reference compounds such as naphthalene or trichloroethylene (TCE) (Figure 1). This approach highlights the relevance of classifying PFAS according to characteristics other than fluorinated chain length to better anticipate their environmental fate and guide technological decision making.

It is also important to highlight that the behaviour and fate of PFAS are influenced by the characteristics of the medium in which they are found. A summary table of the relevant environmental parameters is also provided in the study to support the analysis and to better predict the fate of PFAS.

Figure 1: Representation of the behaviours of the selected PFAS compounds and comparison with reference compounds whose behaviour is well known: TCE, Naphthalene, Pyrene, PCB 77 (RECORD 2025)

The final component of the study presents an up to date review of consolidated and emerging technologies that can be applied to the different matrices originating from channeled flows as well as those present in various environmental receiving media. The table below shows the techniques addressed in this study. The key information for each technology—sometimes complex—has been summarized at the end of the study report in the form of a table.

Table 1: Treatment techniques considered in the study, organized according to their type of application (separation/concentration, destruction, and immobilization) and identified based on their maturity level and field of application (RECORD, 2025)

This study highlights a greater technological diversity for the treatment of liquid matrices than for solid and gaseous matrices. The most mature techniques are also the most widely used on the market for the treatment of other contaminants, which is not a major surprise.

Among the techniques examined, several solutions enable the separation and concentration of PFAS present in liquid matrices. Activated carbon (AC) separation is particularly effective for long chain PFAS. Its use can allow compliance with current French regulatory limits (100 ng/L for the sum of 20 PFAS in drinking water), provided that a sufficient volume of AC is used. However, this technique shows limitations when dealing with high concentrations of short chain PFAS or effluents containing ultrashort chain PFAS, for which AC efficiency is reduced. Although numerous types of AC exist, an overall assessment of their relative performance would be useful.

In this context, ion exchange resins represent an attractive alternative. Despite a higher purchase cost on a weight basis, they offer greater loading capacities and demonstrated effectiveness for the adsorption of short  and ultrashort chain PFAS. Single use resins currently outperform regenerable resins, highlighting the need for continued development to improve the performance of regenerable solutions.

Among other consolidated separation methods, membrane technologies show that reverse osmosis (RO) is more effective than nanofiltration (NF). RO has the advantage of being able to treat the full range of compounds, including ultrashort chain PFAS.

Finally, foam fractionation is a technique increasingly used as a separation/concentration method. Several companies now commercialize it with their own specific configurations. This method has proven effective for effluents with high concentrations of long chain PFAS (>C6). Several research and development avenues (e.g., surfactants, vacuum assisted separation) are currently being explored to improve the separation of short chain compounds.

Regarding separation methods applied to solid matrices, ex situ soil washing is currently the only mature technique. Its effectiveness depends strongly on soil grain size and organic matter content and remains primarily limited to short chain PFAS (<C8). This method therefore cannot, on its own, address all contaminated soil. Moreover, in countries equipped with soil washing facilities, the regulatory trend toward increasingly stringent thresholds makes it essential to develop additional techniques such as desorption processes, particularly for fine soil fractions. These efforts will be crucial to provide treatments that are both compliant with regulatory requirements and economically viable.

At present, thermal desorption shows promising results, but operational feedback remains insufficient. In particular, the lack of data on the gases generated prevents assessing the quality of the gaseous effluent requiring treatment, as well as establishing of a reliable mass balance. This method therefore requires more precise flux based studies.

Among the more experimental technologies, phytoextraction could become a competitive, effective and sustainable treatment option for sites with moderate to high contamination levels. However, substantial knowledge gaps remain regarding the application of this method for PFAS removal, even though potential implementation pathways have been identified for both liquid and solid matrices.

Among the available destruction methods, incineration is currently the only technology available and accepted in France. However, even if the available data indicate high removal rates, these results must be interpreted with caution because they concern only the compounds that were analyzed. As with thermal desorption, the absence of a complete mass balance does not allow any conclusion to be drawn on the total elimination of PFAS.

Regarding alternative PFAS destruction techniques, a growing dynamic of commercial deployment is being observed, with some technologies now arriving in France. Among the promising technologies, supercritical water oxidation (SCWO), hydrothermal alkaline treatment (HALT), and electro-oxidation can be mentioned. For now, these methods can only treat low flow rates and are mainly suitable for liquid matrices. SCWO and HALT can also treat solids, but only in suspension form, with a dry matter content below 20%. In the longer term, these technologies could complement incineration within a dedicated sector for managing highly concentrated wastes such as ion-exchange resins or their wash solutions, non-regenerable activated carbon, and concentrates from reverse osmosis.

Overall, for all destruction-based treatment methods, whether mature or emerging, it is essential to consolidate results using complete mass balances. This requires detailed data based on PFAS fluxes before and after treatment across the different phases (liquid, solid, aqueous) and on any transformation or degradation products. To achieve this, the development of more sensitive, less expensive, and more operational analytical methods, particularly for gaseous matrices (OTM 45 and 50), is indispensable to monitor treatments, meet future regulatory thresholds, and facilitate the deployment of PFAS monitoring.

The study also provides a summary of the effectiveness of the selected PFAS treatment technologies, presented in the form of a summary table. For compounds for which little or no data are available, the assessment is based on their physicochemical properties and on the characteristics of the processes, thus allowing the effectiveness to be estimated by extrapolation, as illustrated in the example below.

Table 2: Assessment of the effectiveness of treatment technologies for the 36 selected PFAS compounds (RECORD, 2025)

Conclusion

This study shows that there is no obvious solution, and that everything ultimately depends on the required energy and on the characteristics of the contaminated matrices requiring treatment. Indeed, all PFAS treatment technologies, whether mature or emerging, are not equally suitable or effective under the same application conditions. For example, adsorption processes such as activated carbon (AC) or ion exchange resins are technically efficient and often economically advantageous for treating large volumes of low concentration liquids, such as drinking water. Conversely, these technologies may be less economically suitable for the continuous treatment of low flow rates with high PFAS concentrations, such as the concentrated foams produced by the film forming process (FF). In contrast, several PFAS destruction technologies, such as electrochemical oxidation, HALT, or SCWO, are potentially effective for low flow rates and high concentrations.

Furthermore, not all technologies exhibit similar performance depending on the type of PFAS compounds. For instance, some processes show limited performance for separating short chain or ultra short chain PFAS, such as AC, whereas membrane processes and resins, under optimal conditions, can allow for more effective separation of these compounds.

Given the specific limitations of each treatment technology, an integrated approach is required: combining multiple technologies within treatment trains to maximize overall performance and limit energy costs. For example, destruction technologies—often costly or complex to implement on their own—must be combined with upstream concentration solutions.

Several points of attention were also identified during this study. To date, most of the available data concern PFCA and PFSA compounds, particularly PFOS and PFOA. This focus limits the ability to fully evaluate the effectiveness of technologies across all PFAS families, including ultra short chain compounds and precursors. Although certain assumptions can be made based on their physicochemical properties and molecular structure, these hypotheses still need to be confirmed by experimental data.

It is also essential to underline that, for a given technology, the maturity level can vary significantly from one provider to another. These disparities directly influence performance, implementation timelines and result reliability. They stem from continuous research and development efforts aimed at improving process efficiency, optimizing costs, and addressing the specific challenges posed by PFAS compounds. In this context, it is strongly recommended to consult several providers at the early stages of a project to compare available solutions, establish a cost benefit balance, and conduct feasibility and treatability tests at laboratory and/or pilot scale.

This approach reinforces the need to systematically integrate techno economic and feasibility studies during the early stages of a project. These studies must consider site specific characteristics, discharge thresholds, and matrix parameters such as soil type, water geochemistry, flow rates, concentrations, treatment duration (temporary/permanent), and the presence of co contaminants.

PFAS are ubiquitous in the environment, in extremely diverse forms, with highly heterogeneous physicochemical behaviours. Even if their production and import were to cease, the stocks already present in soils, waters, and consumer products will continue to circulate through ecosystems for decades, if not centuries. Faced with this reality, it is essential to implement treatment barriers across different flows—whether already treated (e.g., wastewater treatment plants, industrial discharges, leachate treatment facilities) or not yet captured. This strategy must rely on more extensive real world experience, more robust and accessible analytical methods, and clear regulatory thresholds guiding technological choices and priority actions.

Collective mobilisation of all stakeholders is essential to expand knowledge, share practical feedback, and contribute to the shared objective of sustainably reducing PFAS presence in the environment.