Per and poly fluoroalkyl substances (PFAS) is a family of more than 5000 compounds that are used in multiple processes and present in many of our daily products such as papers, garments, food wrappers and cosmetics. As a result, they will reach the wastewater treatment plant (WWTP) through sewage. Common wastewater treatment processes cannot remove or mineralize PFAS. PFAS remain unchanged or biotransformed to other PFAS and tend to partition to the sludge. Several variables affect the PFAS concentrations found in sludge covered to biosolids for land application including source inputs, treatment processes, and the biosolids matrix. Recently EPA released a draft method (1633) for PFAS extraction and analysis of non-drinking water liquids and solids. The draft method varies from methods used over the past decade particularly in the clean-up approach to minimize matrix effects and in the final injection solvent, both can affect limits of quantitation. Here we compare the most commonly used method in the peer-reviewed literature with the EPA 1633 draft method. We also evaluated the effect of biosolid matrix through the recovery of surrogates and internal standards. Three biosolids from different sources and processes including anaerobic digestion, aerobic digestion and one with no digestion were used in the evaluations. QAQC included process blanks with nanopure water, method blanks with reagent grade sand, lab-controlled spikes and matrix and duplicate matrix spikes. Solids were extracted with basic methanol followed by ENVI-Carb cleanup and solid-phase extraction. Final injection solvent composition was prepared with water, isopropanol and methanol. Extracts were analyzed under SWATH mode using ultrahigh performance liquid chromatography quadrupole time of flight mass spectrometry and isotope dilution. A total of 54 PFAS were quantified. Differences in recoveries for the method variations.

Comparative analysis in extraction, analysis and optimization of PFAS in biosolids

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.