The decomposition and emission factors of a wide range of PFAS in diverse, contaminated organic waste fractions undergoing dry pyrolysis

Erlend Sørmo; Gabriela Castro; Michel Hubert; Viktória Licul-Kucera; Marjorie Quintanilla; Alexandros G Asimakopoulos; Gerard Cornelissen; Hans Peter H Arp

doi:10.1016/j.jhazmat.2023.131447

The decomposition and emission factors of a wide range of PFAS in diverse, contaminated organic waste fractions undergoing dry pyrolysis

J Hazard Mater. 2023 Jul 15:454:131447. doi: 10.1016/j.jhazmat.2023.131447. Epub 2023 Apr 18.

Authors

Erlend Sørmo¹, Gabriela Castro², Michel Hubert³, Viktória Licul-Kucera⁴, Marjorie Quintanilla², Alexandros G Asimakopoulos², Gerard Cornelissen⁵, Hans Peter H Arp⁶

Affiliations

¹ Geotechnics and Environment, Norwegian Geotechnical Institute (NGI), Oslo, Norway; Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences (NMBU), Ås, Norway. Electronic address: erlend.sormo@ngi.no.
² Department of Chemistry, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
³ Geotechnics and Environment, Norwegian Geotechnical Institute (NGI), Oslo, Norway; Faculty of Engineering, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
⁴ Institute for Analytical Research, Hochschulen Fresenius gem. Trägesellschaft mbH, Idstein, Germany; Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, Netherlands.
⁵ Geotechnics and Environment, Norwegian Geotechnical Institute (NGI), Oslo, Norway; Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences (NMBU), Ås, Norway.
⁶ Geotechnics and Environment, Norwegian Geotechnical Institute (NGI), Oslo, Norway; Department of Chemistry, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.

PMID: 37121036
DOI: 10.1016/j.jhazmat.2023.131447

Abstract

Current treatment options for organic waste contaminated with per- and polyfluoroalkyl substances (PFAS) are generally limited to incineration, composting or landfilling, all resulting in emissions. Dry pyrolysis is a promising emerging alternative to these practices, but there is uncertainty related to the fate of PFAS during this process. The present work first developed a robust method for the determination of PFAS in complex matrices, such as sewage sludge and biochar. Then, a mass balance was established for 56 different PFAS during full-scale pyrolysis (2-10 kg biochar hr^-1, 500-800 °C) of sewage sludges, food waste reject, garden waste and waste timber. PFAS were found in all wastes (56-3651 ng g^-1), but pyrolysis resulted in a ≥ 96.9% removal. Residual PFAS (0.1-3.4 ng g^-1) were detected in biochars obtained at temperatures up to 750 °C and were dominated by long chain PFAS. Emitted PFAS loads ranged from 0.01 to 3.1 mg tonne^-1 of biochar produced and were dominated by short chain PFAS. Emissions made up < 3% of total PFAS-mass in the wastes. Remaining uncertainties are mainly related to the presence of thermal degradation products in flue gas and condensation oils.

Keywords: Biochar; Emission factors; Mass balance; Method development; Organic waste; PFAS; Pyrolysis; Sewage sludge.