Impact of Several Stabilization Technologies on PFAS in Biosolids

Presentation Description: Per- and Poly-Fluoroalkyl Substances (PFAS) are a large family of organic compounds, including more than 12,000 synthetic fluorinated organic chemicals. Conventional sewage treatment methods do not effectively remove PFAS, leading them to persist in treated solids and biosolids. In 2021, the US EPA identified eight PFAS in biosolids and in January 2025 released a draft biosolids risk assessment report focusing on PFOA and PFOS. If deemed necessary to regulate PFOA and PFOS in biosolids, the US EPA will require biosolids producers to meet certain standards for these compounds—underscoring the importance for biosolids producers to understand the technical solutions available to treat PFAS in biosolids. The focus of this presentation is to help utilities and biosolids producers understand options available to them to mitigate potential PFAS contamination in biosolids. This information will help utility planners, operators, engineers, and administrators better understand the nature of the PFAS issue, how these compounds are introduced into biosolids, the rapidly changing regulatory landscape, and the effectiveness of various technologies to reduce or eliminate measurable concentrations of these compounds from wastewater biosolids products.
Jacobs tested several biosolids products (dried, pyrolyzed, and compost) to assess PFAS concentrations. Using a process known as Liquid Chromatography Tandem Mass Spectrometry (LC/MS/MS), samples of input and output solids and finished products were analyzed for 24 PFAS compounds. Data will be presented on eight dried biosolids facilities, two pyrolyzed dried products, and six compost products. The presentation will cover measured concentrations of PFAS in wastewater solids, dried biosolids, pyrolyzed biosolids, chemical alkyl treated biosolids, incinerator ash, and biosolids-based compost products. PFAS precursor analyte presence and concentrations in the input solids as well as the resultant biosolids products will be presented. This information will be useful for agencies considering methods to reduce or eliminate PFAS in wastewater solids to achieve the lowest feasible PFAS concentrations in end products.