Biosolid based biochar for PFAS attenuation from biosolids

Alukkal, Caroline

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https://hdl.handle.net/2142/114119 Copy

Description

Title

Biosolid based biochar for PFAS attenuation from biosolids

Author(s)

Alukkal, Caroline

Issue Date

2022-04-27

Keyword(s)

• Per- and polyfluoroalkyl substances
• PFAS
• emerging contaminants

Abstract

Per- and polyfluoroalkyl substances (PFAS) are difficult to remove by conventional wastewater treatment processes and partition to biosolids causing concerns when they are land applied. We evaluated the use of biosolids-based biochar produced by pyrolysis of a Class A biosolid at 350°C under nitrogen. PFAS were quantified using liquid chromatography Quadrupole Time of Flight mass spectrometry and isotope dilution. A 16% mass reduction occurred along with total PFAA concentrations reduction from 873 ± 5 µg/kg in the biosolid to 678 ± 5 µg/kg in the biochar. We also measured PFAS release from the biochar into porewater by equilibrating 3 g of biochar in 6 ml water for 48 hours. Total PFAS concentrations released was only 12 ± 0.1 µg/kg compared to several thousand ppt prior to pyrolysis. Batch tests were conducted to assess the attenuation capacity of biochar for additional PFAAs from two different biosolid-derived porewaters to which additional PFAAs were added to increase initial PFAA concentrations. PFAA adsorption increased with biochar mass and perfluorocarbon chain length with >80% sorption for longer chain PFAS. Therefore, we propose co-application of biochar with biosolids offers a strategy for sustainable use of biosolids.

Series/Report Name or Number

2022 Emerging Contaminants in the Environment Conference (ECEC22)

Type of Resource

• text
• still image

Language

en

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http://hdl.handle.net/2142/114119

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