Removal of per- and polyfuoroalkyl substances and organic fuorine from sewage sludge and sea sand by pyrolysis

0584759 - ÚCHP 2025 RIV DE eng J - Journal Article
Hušek, Matěj - Semerád, Jaroslav - Skoblia, S. - Moško, Jaroslav - Kukla, J. - Beňo, Z. - Jeremiáš, Michal - Cajthaml, Tomáš - Komárek, M. - Pohořelý, Michael
Removal of per- and polyfuoroalkyl substances and organic fuorine from sewage sludge and sea sand by pyrolysis.
Biochar. Roč. 6, č. 1 (2024), č. článku 31. ISSN 2524-7972
R&D Projects: GA MZe(CZ) QK21020022; GA TA ČR(CZ) SS02030008
Grant - others:AV ČR(CZ) StrategieAV21/3
Program: StrategieAV
Institutional support: RVO:67985858 ; RVO:61388971 ; RVO:61389021
Keywords : sewage sludge * PFAS * pyrolysis * carbonization * organic fluorine
OECD category: Environmental sciences (social aspects to be 5.7); Environmental sciences (social aspects to be 5.7) (MBU-M); Environmental sciences (social aspects to be 5.7) (UFP-V)
Impact factor: 12.7, year: 2022
Method of publishing: Open access
https://link.springer.com/article/10.1007/s42773-024-00322-5

Pyrolysis is one method for treating sewage sludge, particularly in remote areas or decentralised systems. The end product of pyrolysis, sludge-char, can serve as a soil improver. However, there is a lack of comprehensive data on the organic pollutants’ behaviour in sludge-char. In our work, we focused on the behaviour of per- and polyfuoroalkyl substances (PFASs). Sludge was pyrolyzed at 200–700 °C to determine the minimum safe temperature for efective PFASs removal. It is important to note that PFASs may not only be mineralized but also cleaved to unanalyzed PFASs and other organofuorinated substances. To address this issue, we incorporated additional measurements of organic fuorine in the experiment using combustion ion chromatography (CIC). Due to the inherent heterogene ity of sludge, containing a variety of pollutants and their precursors, we conducted pyrolysis on artifcially contaminated sand. This allowed us to assess and compare the behaviour of PFASs in a homogeneous matrix. Based on our analyses, we determined that a temperature greater than 400 °C is imperative for efective PFASs and organic fuorine removal. The results were verifed by analyzing samples from a commercial sludge pyrolysis unit at the BohuslaviceTrutnov WWTP, which confrmed our measurements. In light of these results, it becomes evident that sludge pyrolysis below 400 °C is unsuitable for PFAS removal from sewage sludge.
Permanent Link: https://hdl.handle.net/11104/0352603