SUMMARY

• This study evaluated the feasibility of controlling PFAS bioavailability in biosolids-amended soil using two approaches: stabilisation through the addition of a sorbent and mobilisation through the addition of a surfactant.
• RemBind® applied at 2% was highly effective at stabilising PFAS and reducing their uptake by timothy-grass. PFAS concentrations in grass shoots grown in RemBind® treated soils was only 3.35% of that detected in untreated biosolids-amended soil.
• Biochar increased PFAS uptake by timothy-grass, indicating it is not an effective stabilisation agent for PFAS in biosolids-amended soil.
• Mobilisation using SDS at doses of 10 to 100 mg/kg significantly increased plant uptake of PFAS by between 15.48% and 108.57%, demonstrating its potential as a complementary approach when phytoremediation is the chosen strategy.
• Mowing and regrowth of timothy-grass further promoted PFAS uptake, suggesting that a managed cutting cycle could improve the efficiency and cost-effectiveness of phytoremediation for PFAS-contaminated biosolids-amended soil.
• The study confirms that RemBind® at a 2% application rate is very effective in stabilising PFAS and significantly reducing their bioavailability in land-applied biosolids scenarios.