Managing Per- and Polyfluoroalkyl Substance (PFAS) Contamination in Agricultural Soils: Investigating Remediation Approaches in Non-conventional Agriculture

Abstract. Common practices in non-conventional agriculture such as organic farming, conservation agriculture, agroecology and regenerative agriculture entail the use of organic fertilisers, including urban/industrial composts, treated manure and biosolids, while minimising the use of commercially available mineral fertilisers. Fertilisation of soils with organic amendments is also a common strategy used in drylands (arid, semi-arid and dry sub-humid areas), which face two main challenges: low soil organic matter content and water scarcity. The latter issue can be partly addressed by the use of reclaimed wastewater. However, these approaches may pose signiﬁcant risks to the agroecosystem and agricultural products. Biosolids and reclaimed wastewater often contain various contaminants due to the continuous inputs into wastewater treatment plants and the inefﬁciency of wastewater treatment technology in eliminating (and degrading) numerous contaminants. Notably, perand polyﬂuoroalkyl substances (PFAS) are considered “legacy” pollutants that continue to raise concern because of their high environmental persistence and the introduction of alternative PFAS with unknown effects. This chapter explores the main pathways of PFAS contamination in agriculture and the effects on soil function. Interactions of PFAS with plants, soil microorganisms and macrofauna (e.g. earthworms) are discussed in the context of their potential contribution to bioremediation. Most remediation technologies for PFAS-contaminated soils are engineered-based and often result in disruption of the soil structure, as well as alterations in physicochemical and biological properties, presenting suboptimal solutions for agricultural soils. Although still at early stages, we propose adopting biological strategies for immobilising PFAS, thereby reducing the adverse impact of these compounds on soil function and minimising residues in agricultural products. These strategies encompass both in situ methods and the biological treatment of amendments contaminated by PFAS, such as vermicomposting. The chapter concludes with an outlook encouraging future research in bio-based technologies for inactivating PFAS in agricultural soils and organic amendments.

Authors: Juan C. Sanchez-Hernandez , Rodrigo Pardo Fernández, Natividad I. Navarro Pacheco, Ximena Andrade Cares, and Jorge Domínguez

The publication is available on: Soil Remediation Science and Technology | SpringerLink