US Department of Defense–Funded Research on Treatment of Per- and Polyfluoroalkyl Substance–Laden Materials

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:PFAS処理技術の研究開発動向を把握するための参考になる。

🏢実務担当者:PFAS処理に関わる企業は、最新の処理技術とコスト削減の可能性を理解できる。

🏛政策担当者:PFAS規制や処理技術の政策立案に際し、技術の現状と課題を認識する必要がある。

The scope of the present article is the status of the research, development, and demonstrations of treatment technologies for per- and polyfluoroalkyl substance (PFAS)-laden material that are funded by the Strategic Environmental Research and Development Program (SERDP) and the Environmental Security Technology Certification Program (ESTCP). Both SERDP and ESTCP are US Department of Defense (DoD) programs and are coordinated with the US Environmental Protection Agency and the US Department of Energy. The present article is 1 of a 3-part series of Focus articles on the status of research, development, and demonstration efforts that will assist project delivery teams, within the DoD, in their efforts to manage an expansive portfolio of aqueous film-forming foam (AFFF)-impacted sites. The present article focuses on treatment technologies, and the second article in the series covers fate and transport. A third, overview, article briefly summarizes exposure pathways; analytical and environmental sampling methods; fate and transport; characterization; bioaccumulation, ecotoxicity, and ecological risk assessment; and treatment technologies. The PFAS have been recognized as being one of the most persistent categories of anthropogenic chemicals found in the environment. In contrast to chlorinated solvents, these fluorinated compounds are largely impervious to common biological degradation processes and conventional chemical oxidation processes. They are a concern for the DoD and for municipal airports, due to the use of legacy AFFFs. They are also a concern for the community at large, due to the presence of PFAS in consumer products. Ex situ groundwater treatment has become a common alternative for managing PFAS-impacted groundwater. Although existing technologies are acceptable for ex situ treatment of PFAS-impacted groundwater (e.g., relying on adsorptive media such as granular activated carbon [GAC]), operation of these pump-and-treat systems represents a considerable and growing expense, especially as more of these systems have to be installed across the United States. Technologies such as GAC and ion exchange continually generate residuals (e.g., spent media) that require off-site treatment and/or disposal. Large quantities of investigation-derived wastes (IDW) continue to be generated during characterization of PFAS-impacted sites. More cost-effective alternatives are needed for disposal of residuals, and PFAS-laden IDW materials (e.g., drill cuttings, well development water). Given the substantial number of pump-and-treat systems that are currently in operation, sizable cost savings can be realized via development of more cost-effective treatment technologies. Advances may be realized in many different forms: improved media for groundwater treatment that require much less frequent replacement; media with improved capabilities for removing short-chain PFAS constituents; destruction technologies to allow for on-site treatment of groundwater, spent media, regenerant solutions, and/or IDW; and improved destruction technologies for off-site treatment of residuals and IDW. Development of effective in situ treatment technologies for PFAS-contaminated groundwater represents another important goal. Considerable cost savings will be realized if a portion of the existing pump-and-treat systems can be replaced with passive, in situ treatment systems. The treatment technologies we discuss are broadly classified as either ex situ or in situ (Figure 1 and Tables 1–3). For the ex situ treatment technologies, the projects are primarily subclassified under the following categories: aqueous media treatment, investigation-derived wastes/soils, and residuals. Residuals includes materials such as spent treatment media (GAC and ion exchange resin), and concentrated brines derived from regeneration of ion exchange resin. Some of the treatment technologies under development do not necessarily fit within a single category (e.g., plasma-based treatment processes can be applied to aqueous media, IDW water, and brine regenerant solutions). Also, some of the ex situ treatment technologies could potentially be applied in situ. The present article is not intended to provide comprehensive coverage of each and every PFAS treatment project being funded by SERDP and ESTCP, but rather to provide an overview, and to highlight a select list of representative treatment projects. D. Call, (North Carolina State University, Raleigh, NC, USA) Proof-of-concept (POC) in progress D. Chiang (CDM Smith, New York, NY, USA) M. Crimi (Clarkson University, Potsdam, NY, USA) POC in progress M. Fuller (Aptim, Baton Rouge, LA, USA) POC follow-on effort in progress K. Ozekin (Water Research Foundation, Denver, CO, USA) F. Barranco (EA Engineering, Science, and Technology, Hunt Valley, MD, USA) Proof of concept (POC) complete T. Boving (University of Rhode Island, South Kingston, RI, USA) POC in progress E. Cates (Clemson University, Clemson, SC, USA) POC follow-on effort in progress B. Chaplin (University of Illinois at Chicago, IL, USA) POC in progress H. Cho (The University of Texas at Arlington, TX, USA) POC in progress T. Holsen (Clarkson University, Potsdam, NY, USA) POC in progress D. Jassby (University of California, Los Angeles, CA, USA) POC in progress P. Koster van Groos (Aptim, Princeton, NJ, USA) POC in progress S.D. Pillai (Texas A&M University, College Station, TX, USA) POC follow-on effort in progress J. Quinnan [B] (Arcadis, Brighton, MI, USA) C. Sales (Drexel University, Philadelphia, PA, USA) POC follow-on effort in progress T. Strathmann (Colorado School of Mines, Golden, CO, USA) POC in progress J. Wehrmann (Paragon, Anchorage, AK, USA) H. Yu (Amriton, Norristown, PA, USA) POC complete POC follow-on effort in progress The stability of the C–F bond is believed to be due to the inherent bond strength, and the short length of the bond. The C–F bond is the strongest single bond known to organic chemistry, with a bond dissociation energy as high as 544 kJ/mol (for tetrafluoromethane). Because of the close proximity of the fluorine atoms that are bound to the carbon atoms, the outer fluorine atoms shield the underlying carbon backbone of PFAS constituents from reactive species. Owing to the extraordinary stability of the C–F bonds within PFAS, a considerable amount of energy is required to defluorinate PFAS constituents. Thus, destruction technologies for PFAS-laden materials are relatively energy intensive, whereas nondestructive treatment processes are much less energy intensive. In general, the energy efficiency of destruction technologies for PFAS-laden materials is greater for moderate or highly concentrated waste streams; however, most of the destruction technologies can be applied to either dilute or concentrated waste streams. Nondestructive processes may be coupled with destructive processes to achieve a complete treatment solution (e.g., use of ion exchange resin to treat groundwater, coupled with incineration of spent media). The development of complete and energy-efficient treatment solutions is critical. Both lifecycle costs and greenhouse gas emissions will need to be taken into consideration, to compare and rank the merits of specific processes and combinations of processes. Analysis of groundwater from AFFF fire training source areas has revealed that a large fraction of the total organic fluorine remains unmeasurable via conventional analytical methods (Schaefer et al. 2019). A groundwater sample from a DoD fire training source area was tested for the standard 24 PFAS analytes, total oxidizable precursors (TOPs), and also for total organic fluorine via combustion ion chromatography (TOF–CIC). The result from the TOP assay was added to the sum-total result from the 24 measured PFAS analytes, and then compared with the result from TOF–CIC assay. The TOF-CIC assay result was much higher, and comparison of the results indicated that approximately 65% of the organic fluorine present in the sample was not accounted for by adding the result from the TOP assay to the sum-total result from the 24 measured PFAS analytes. This finding has important implications for PFAS treatment technologies. The presence of unmeasurable PFAS constituents (i.e., “dark matter”) has an important impact on the capacity of adsorbent media, and ion exchange resins. Also, the presence of unmeasurable PFAS constituents increases the energy requirements for PFAS destruction technologies and makes it more difficult to predict when change-out of adsorbent media will be required. This is one reason why site-specific column testing and/or pilot test data are critically important for design of full-scale treatment systems, for estimating lifespan for treatment media, and for estimating electrical power costs for destruction technologies. Aqueous media can be generally divided into 2 categories for the context of treatment: relatively dilute waste streams (e.g., groundwater and drinking water), and moderately concentrated waste streams (e.g., surface water impoundments that have been used to collect run-off with relatively high concentrations of PFAS). Highly concentrated brines from regeneration processes are discussed later in the Treatment of residuals section. Nondestructive treatment processes include GAC and ion exchange, which have become the default technologies for treatment of dilute aqueous media. Reverse osmosis and membrane filtration (RO/MF) processes are less widely used, but are also included in this category. Both GAC and ion exchange are generally favored over RO/MF processes because they are less energy intensive. The RO/MF processes require relatively high pressures to force the influent through nanoporous membranes. Single-use ion exchange resins are used more frequently than regenerable ion exchange resins. If the influent PFAS levels are high enough, then selection of a regenerable ion exchange resin may be justified. When the PFAS levels exceed a thresh

• openalex https://doi.org/10.1002/etc.4836first seen 2026-08-02 16:58:21