Presentation: 2025 ND EPSCoR Annual conference 

October 21, 2025, NDSU Memorial Union, Fargo, North Dakota

Nanoscale Inorganic Boron-Based Adsorbents for Enhanced Removal of PFAS from Water

Co authors: Per- and polyfluoroalkyl substances (PFAS), widely known as “forever chemicals,” are persistent contaminants in drinking water that present significant health risks due to their toxicity. Among current treatment strategies, adsorption remains the most effective approach for reducing PFAS to parts-per-trillion (ppt) levels, with granular activated carbon (GAC) and ion exchange (IX) resins serving as the standard adsorbents. However, the recently established Maximum Contaminant Levels (MCLs) by the U.S. EPA are expected to drive increased demand for adsorbents, highlighting the need for more sustainable and cost-effective alternatives. This study investigates the adsorption performance of two inorganic materials—pristine boron and boron-doped silica gel- for the removal of ten PFAS compounds from water. Boron-doped silica gel, synthesized using a nanotechnology-based approach, demonstrated superior adsorption compared to pristine boron. At pH 7.0, pristine boron exhibited an adsorption capacity of 0.3459 mg/g at a 1 g/L dosage, whereas boron-doped silica gel achieved 285.8455 mg/g at a 0.5 g/L dosage. Adsorption behavior was strongly dependent on PFAS molecular characteristics: longer-chain PFAS displayed higher adsorption efficiency than shorter-chain compounds, and sulfonic acid head groups showed greater affinity than carboxylic acids of equivalent chain length. These results establish boron-doped silica gel as a highly efficient and sustainable adsorbent with strong potential to replace or complement conventional materials in PFAS treatment. Its exceptional performance underscores the promise of inorganic adsorbents as next-generation solutions for achieving regulatory compliance.