Distribution, advanced separation and degradation technologies for per- and polyfluoroalkyl substances removal in water: Efficiency, challenges, and future perspectives

Per- and polyfluoroalkyl substances (PFASs) have emerged as a critical environmental issue due to their high persistence, bioaccumulation, and adverse health effects at nanogram per liter (ng/L) concentrations. This review systematically evaluated the distribution of PFAS in the aqueous environment and their removal using advanced separation and degradative techniques, addressing the efficiencies, limitations, and future perspectives. Separative techniques (such as adsorption and membrane filtration) exhibited high PFAS removal efficiencies. Activated carbon (AC) can remove 60-90% of long-chain PFAS (e.g., perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS)), whereas ion exchange resins exceed 95% under optimized conditions. However, short-chain PFAS (e.g., perfluorobutanoic acid (PFBA), perfluorobutanesulfonic acid (PFBS)) are less effectively removed by AC owing to its weaker hydrophobic interactions. Metal-organic frameworks (MOFs) such as universitetet i oslo (UiO-66), materials of institute lavoisier (MIL), and zeolitic imidazolate framework (ZIF) showed >90% capture for PFOS. Membrane processes, such as nanofiltration (NF) and reverse osmosis (RO) can achieve >90% PFAS rejection, but membrane fouling and concentrate disposal are still serious problems to be solved. Moreover, degradative methods, especially advanced oxidation processes (AOPs) and the electrochemical approach, offer a potential for PFAS mineralization and achieve>90% PFAS degradation at high energy inputs; however it face byproduct generation and energy challenges. While microbial degradation remains inefficient as most PFAS require genetically engineered strains effective removal. Future research needs to tackle these issues and must prioritize sustainable, cost-effective solutions to address PFAS contamination comprehensively.