Assessment of the Possible Inhibitory Effect of PFAS-Containing Aqueous Wastes on Aerobic Biomasses

Per- and polyfluoroalkyl substances (PFASs), known as "forever chemicals," are synthetic organofluorine compounds widely used since the 1940s due to their chemical and thermal stability. However, growing concerns about their environmental and human health risks have emerged. Although the toxicity of PFASs to humans has been extensively researched, their effects on microbial consortia in wastewater treatment plants (WWTPs) have not been as thoroughly investigated. This study evaluates whether aqueous wastes (AWs) containing PFASs inhibit aerobic biomasses from various WWTPs. Approximately 400 respirometric tests showed no acute toxicity. However, biomass tolerance varied based on acclimatization. Biomass from a municipal WWTP was more tolerant to AWs with short-chain PFASs, whereas biomass from a WWTP authorized to receive AWs was less inhibited by AWs rich in long-chain PFASs. These findings highlight the potential role of municipal WWTPs in treating PFAS-contaminated AWs and emphasize the need for tailored treatment strategies to minimize environmental risks.