Fate of PAPs and short-chain PFAS in biosolids amended soils

Biosolids are an important source of nutrients supporting the agricultural industry. However, biosolids generated during wastewater treatment contain PFAS (per-and poly fluoroalkyl substances) which are persistent, bioaccumulative and toxic. Application of biosolids to agricultural land may result in PFAS contamination of soil, groundwater and surface water via leaching and run-off, which pose potential risk to soil health, crops and beneficial biota. This study aims to generate novel knowledge on the fate of PFAS in biosolid-amended soils, crops and toxicity to key soil and aquatic biota at environmentally relevant concentrations. The specific objectives of the project are to:

• Investigate the degradation pathways of polyfluoroalkyl phosphates (PAPs) in biosolids and biosolid-amended agricultural soils.
• Elucidate the potential for short-chain per- and polyfluoroalkyl substances (PFAS) and PAPs to migrate and contaminate surface and subsurface waterbodies through batch and column experiments.
• Gain a mechanistic understanding of the uptake, translocation, transformation and accumulation of PAPs and short-chain PFAS in crop plants using physiological and metabolomic approaches.
• Determine the accumulation potential, acute and chronic toxicity of short-chain PFAS at environmentally relevant concentrations to key terrestrial (on-site) and aquatic biota (off-site impacts).
• Develop a guidance document, in collaboration with EPA, about the potential risks of short-chain PFAS to agricultural soils and adjacent waterbodies.

This project is funded by the ARC (LP220100375), WaterRA, a collective of water utilities, Intelligent Water Networks and supported by EPA Victoria. This is a collaborative effort to ensure that biosolids application to agricultural lands is done in an environmentally sustainable way that benefits Australian farmers and communities.