Distribution of Per- and Polyfluoroalkyl Substances (PFASs) in a Waste-to-Energy Plant─Tracking PFASs in Internal Residual Streams

Occurrence and mass flow rate of PFAS in a Waste-to-Energy water treatment process

This study investigated the fate of per- and polyfluoroalkyl substances (PFAS) in the in-house process-water treatment (PWT) of a 65 MW Waste-to-Energy (WtE) plant. PFAS are used in a wide variety of applications, but are persistent and will end up in waste streams when products reach the end of their lives. The study aimed to identify the pathway of PFAS from flue-gas treatment to the PWT, and to assess the efficiency of the PWT in removing PFAS. Sampling was conducted over five days at five different locations in the PWT. Nine of the eleven target PFAS were detected in at least one sample. The total concentration of PFAS exhibited day-to-day variations, likely caused by fluctuations in the composition of the waste fuel. The highest average PFAS concentration was observed in foam, and was around 130 times that found in the treated water. However, the mass flow of PFAS in the foam was substantially lower, on average 20 times, than that in the treated water. It was found that the condensate scrubber acts as a PFAS transfer step, carrying over certain PFAS from the flue gases into the condensate and PWT. The mass flow rate of PFAS in the PWT after the addition of condensate was six times that before the addition. The study concludes that, while there are some key changes that could be made to enhance the PFAS removal capacity of the in-house PWT, in its current configuration the PWT is not able to efficiently remove PFAS from process-water.

State of the science and regulatory acceptability for PFAS residual management options: PFAS disposal or destruction options

This systematic review covers the urgent challenges posed by per- and polyfluoroalkyl substances (PFAS) in managing residuals from municipal, industrial, and waste treatment sources. It covers regulatory considerations, treatment technologies, residual management strategies, and critical conclusions and recommendations. A rigorous methodology was employed, utilizing scientific search engines and a wide array of peer-reviewed journal articles, technical reports, and regulatory guidance, to ensure the inclusion of the most relevant and up-to-date information on PFAS management of impacted residuals. The increasing public and regulatory focus underscores the persistence and environmental impact of PFAS. Emerging technologies for removing and sequestrating PFAS from environmental media are evaluated, and innovative destruction methods for addressing the residual media and the concentrated waste streams generated from such treatment processes are reviewed. Additionally, the evolving regulatory landscape in the United States is summarized and insights into the complexities of PFAS in residual management are discussed. Overall, this systematic review serves as a vital resource to inform stakeholders, guide research, and facilitate responsible PFAS management, emphasizing the pressing need for effective residual management solutions amidst evolving regulations and persistent environmental threats.