This SERDP and ESTCP webinar presents an evaluation of environmentally friendly alternatives to AFFF, as well as a novel technology to destroy PFAS in contaminated groundwater. Specifically, investigators will summarize research and current understanding of PFAS defluorination and reaction mechanisms for PFAS degradation using hydrated electrons generated under ultraviolet irradiation, and will also present results of real-scale and laboratory-scale experiments assessing the effectiveness of AFFF alternatives, including PFAS-free foams as well as wetting agents and other water additives.


Webinar #121 (10/22/2020)
Managing AFFF Impacts to Subsurface Environments and Assessment of Commercially Available PFAS-Free Foams (Part 2)

Dr. Jinyong Liu, University of California Riverside

Mr. Gerard Back, Jensen Hughes

October 22, 2020

12:00 PM ET (9:00 AM PT)

Presentation Slides


Understanding and Improving PFAS Degradation with Advanced Reduction and Oxidation Methods by Dr. Jinyong Liu (SERDP Project Webpage)

This project supports SERDP’s efforts to remove and destroy PFAS in contaminated groundwater at Department of Defense (DoD) sites. Hydrated electrons can be generated under ultraviolet irradiation and have exhibited great promises for reductive PFAS destruction in practical applications. One of the core research objectives is to understand the governing reaction mechanisms for PFAS degradation. This information is critical to achieving deep defluorination of most PFAS structures and designing a cost-effective treatment system. Our research has elucidated the structure-reactivity of major PFAS categories and significantly improved the defluorination ratio and energy efficiency. This presentation will describe the main mechanistic insights and demonstrate the system performance of PFAS degradation under simulated remediation conditions.

Capabilities Assessment of PFAS-Free Foams and Water Additives” by Gerard G. Back (ESTCP Project Webpage)

Legacy firefighting foams (AFFF) used by the DoD are facing increasing regulatory scrutiny throughout the world due to both environmental and human health concerns associated with the fluorinated surfactants. This SERDP project is a two-year effort to assess the capabilities of environmentally friendly AFFF alternatives including both traditional candidates such as PFAS-free foams, and non-traditional options such as wetting agents and other water additives. The program provides an “apples to apples” comparison of the capabilities of the AFFF formulations currently used by the DoD and the commercially available PFAS-free alternatives. The capabilities were assessed against a range of representative real-scale conditions/scenarios as well as on a laboratory/approval type scale. The data collected were used to quantify the capabilities of the various alternatives during typical use type scenarios and then linked to the smaller laboratory/approval scale test results to develop a better understanding of the approval scale test results. In the future, the results of the program will validate the potential for using a commercially available agent as an alternative for AFFF, and will begin the development of a database for future reference. In October 2019, the objectives and approach to the program were presented in a SERDP ESTCP Webinar (#100). This webinar will provide an update on the program, including a discussion of recent results and the path forward to project completion.

Speaker Biographies

Dr. Jinyong Liu is an Assistant Professor in the Department of Chemical and Environmental Engineering at the University of California, Riverside. His current areas of research focus on the development of chemical technologies for the degradation of water pollutants, such as PFAS and oxyanions (perchlorate, chlorate, nitrate, and bromate). Dr. Liu has served as the principal investigator on several research grants focused on (1) degradation of a variety of PFAS using advanced reduction and oxidation methods for groundwater remediation, (2) development of heterogeneous catalysts for oxyanion reduction, and (3) investigation of the coordination chemistry of transition metals involved in pollutant degradation. He earned a bachelor’s degree in chemistry and a master’s degree in environmental science and engineering from Tsinghua University in Beijing, and a doctoral degree in environmental engineering from the University of Illinois at Urbana-Champaign.


Gerard (Jerry) G. Back is a Senior Fire Protection Engineer with Jensen Hughes in Baltimore, Maryland. He was one of the original Hughes Associate employees and has over 35 years of experience covering the spectrum of fire protection topics and issues. Over the course of his career, he has published over 100 papers on fire protection related topics and has been responsible for project management and administration (planning, execution, and analysis) of fire protection research, development, testing, and evaluation programs. He has performed thousands of full-scale fire tests including evaluations of AFFF agents and systems, aerosols, high expansion foam systems, gaseous agents, water mist systems, and water spray/delude systems. His experience has included major projects for the U.S. Air Force, Army, Coast Guard, Navy, the Federal Aviation Administration, and commercial clients. He has tested every type of AFFF system used throughout the U.S. Navy (including most manual firefighting equipment) and is actively testing a range of potential AFFF alternatives. He recently completed a parametric assessment of Underwriters Laboratories listed commercially available PFAS-free foams for the National Fire Protection Association Fire Protection Research Foundation that consisted of 165 tests. He has a bachelor’s degree in mechanical engineering and a master’s degree in fire protection engineering, both from the University of Maryland.