Enhanced selective adsorption of perfluoroalkyl substances through an integration of quaternized cellulose nonwoven and micro-nano-bubbles

Quaternized cellulose nonwovens (QCNWs), easy-separable monolithic sorbents, were prepared and combined with micro-nano bubbles (MNBs) for the selective adsorption of perfluoroalkyl substances. QCNWs could be easily prepared through a 1-hour reaction at 40 °C using low-cost raw materials. At a given initial concentration of 40 mg L⁻¹ for perfluorooctane sulfonates (PFOS), an integration of QCNWs and air MNBs increased the equilibrium adsorption capacity (q_e) from 179.3 to 272.5 mg g⁻¹ and reduced the equilibrium time (t_e) from 4 to 0.5 h, leading to a significant increase of q_e/t_e value from 44.8 to 545.0 mg g⁻¹ h⁻¹. This combination minimized the interference from common inorganic anions and humic acid and removed over 98.0% of PFOS (2 mg L⁻¹) from tap water within 1 h, while only 65.0% removal achieved after 8 h without MNBs. Owing to the improved adsorption rate and capacity, the integration process enhanced energy efficiency by 8 times. QCNWs demonstrated a regeneration efficiency exceeding 90% over six cycles. Mechanistic studies revealed that the amphiphobic nature of PFASs promotes their enrichment at the gas–liquid interface of MNBs, leading to increased negative surface charges and enhanced electrostatic attraction to QCNWs. This synergistic interaction facilitates efficient and selective adsorption. The combination of sustainable, eco-friendly QCNWs and MNBs presents a feasible effective process for the remediation of PFASs-contaminated water.