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.