Studying biosorption materials for water PFAS removal in a flow-through configuration

Per- and polyfluoroalkyl substances (PFAS) are persistent pollutants of global concern due to their strong C–F bonds and exceptional resistance to degradation, which make their removal challenging. Conventional treatment methods such as reverse osmosis, nanofiltration, and activated carbon adsorption often show low efficiency for long-chain PFAS and require high operational costs. This study investigates a sustainable adsorption strategy using pinewood-derived biochar (PW) produced at 850 °C and 1000 °C, with varying particle sizes and including surface functionalization by cetyltrimethylammonium bromide (CTAB). Adsorption experiments were performed in a continuous flow reactor (CSTR) to ensure reproducibility, effective phase separation, and dynamic flow conditions. CTAB-functionalized PW biochar exhibited enhanced adsorption capacity compared to unmodified biochar and comparable performance to commercial activated carbon in long-chain PFAS removal. The use of pinewood residues as a feedstock demonstrates a valorization pathway for industrial and forestry by-products, aligning with circular economy principles and sustainable waste management. Overall, the study highlights engineered biochar as an efficient, low-cost, and environmentally friendly alternative to conventional adsorbents, offering a promising solution for PFAS remediation that integrates pollutant removal with resource recovery.