Integrated Thermal and Phyto-Remediation of Agricultural Soils Impacted by PFAS

Widespread biosolids application has introduced per- and polyfluoroalkyl substances (PFAS) into millions of hectares of agricultural soils, yet existing remediation methods are costly, carbon intensive, and impractical at scale. We evaluate an integrated strategy that combines phytoremediation, biomass pyrolysis, and enhanced weathering to remove PFAS while generating durable carbon dioxide removal (CDR). Using stochastic modeling constrained by experimental data, we show that raising soil pH with alkaline rock amendments increases PFOS mobility and plant uptake, shortening remediation timelines by more than a decade under typical contamination levels. Pyrolysis of harvested biomass destroys PFAS and produces biochar that, when returned to soil, limits groundwater leaching by more than 95%. National-scale simulations across ~1 million hectares of contaminated cropland yield a combined CDR potential of ~12 Mt CO₂ yr⁻¹, or 4–6% of the U.S. 2050 target. Remediation costs of ~1,300 USD ha⁻¹ yr⁻¹ are over an order of magnitude lower than conventional approaches.