Analytical protocol for detection and prioritization of per- and polyfluoroalkyl substances (PFAS) in biosolid leachates

• Published in: Journal of water process engineering 2024-12, Vol.68, p.106546, Article 106546
• Main Authors: Ocheje, Joshua Omaojo, Mendoza Manzano, Maria, Nasir, Zariah, Katsenovich, Yelena, Tansel, Berrin, Sivaprasad, Shyam, Quinete, Natalia
• Format: Article
• Language: English
• Subjects: Liquid-chromatography mass spectrometry; PFAS; Sludge; South Florida; Wastewater treatment plants
• ISSN: 2214-7144; 2214-7144
• DOI: 10.1016/j.jwpe.2024.106546

Land application of biosolids from wastewater treatment plants (WWTPs) can potentially release per- and polyfluoroalkyl substances (PFAS) into the environment. Limited data is available on PFAS types and levels in biosolids from South Florida. This study outlines analytical protocols for detecting and quantifying PFAS in biosolid leachate and solid residue, by modifying and validating a method based on the U.S. EPA Method 1633. The method achieved detection limits as low as 0.02 ng/L in leachate and 0.01 ng/g in the biosolid residues and was applied to samples from two Miami-Dade WWTPs, in which 22 of 40 targeted PFAS were detected in leachates and 19 in solid residues after leaching. Distinct PFAS composition and levels were observed among the WWTPs, whereas the sum of PFAS (∑22PFAS) in leachates ranged from 57 to 463 ng/L, and in the solid residue ∑19PFAS ranged from 187 to 571 ng/g. The 5:3 Fluorotelomer carboxylic acid (5:3 FTCA) was the most prevalent and abundant PFAS found, with a detection frequency between 83 % and 100 %. Key PFAS were prioritized based on their concentration and detection frequency. These findings highlight PFAS occurrence and distribution in biosolids at different treatment stages, underscoring the need for further monitoring and regulation. [Display omitted] •Modified USEPA Method 1633 validated for determining PFAS in biosolid leachate and solid residue.•Low method detection limits were obtained in the biosolid leachate and solid residue methods.•FPePA, PFBA, PFHxA, PFOA, PFOS, PFPeA, PFHxS, and FHpPA were prioritized in biosolids.•Differences in PFAS composition and levels between two treatment plants attributed to influent sources.•Higher PFAS concentrations at one plant are likely related to landfill leachate input.