Age-dependent PFAS composition and removal behavior in membrane distillation of landfill leachate
Desalination, cilt.638, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 638
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.desal.2026.120550
- Dergi Adı: Desalination
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, Environment Index, Geobase, INSPEC, Public Affairs Index, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Anahtar Kelimeler: Landfill leachate, Leachate age, Long-chain PFAS, Membrane distillation, Per- and polyfluoroalkyl substances (PFAS), Short-chain PFAS
- Yıldız Teknik Üniversitesi Adresli: Evet
Özet
This study investigates the influence of landfill age on per - and polyfluoroalkyl substances (PFAS) composition and their removal behavior during direct contact membrane distillation (DCMD). Leachate samples representing three stabilization stages were collected from a municipal solid waste landfill and analyzed for 24 target PFAS, of which 18 were detected above the limit of quantification (LOQ). Total PFAS decreased with landfill age, from 86.98 μg/L in young landfill leachate (YLFL) to 63.13 μg/L in aged landfill leachate (ALFL), accompanied by a shift toward long-chain dominance. DCMD experiments were conducted using polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF) membranes at feed temperatures ranging from 50 to 80 °C. Over 93% PFAS rejection was achieved under all conditions, indicating the effectiveness of membrane distillation (MD) in removing PFAS from landfill leachate. However, distinct separation behavior was observed depending on PFAS chain length. Short-chain PFAS exhibited higher permeation than long-chain compounds, dominating the permeate composition despite lower or comparable feed fractions. This behavior may be associated with chain-length-dependent interfacial partitioning and weaker hydrophobic interactions with the membrane surface, thereby facilitating the preferential occurrence of short-chain PFAS in the permeate. PTFE membranes demonstrated superior rejection and flux stability compared to PVDF due to higher hydrophobicity and resistance to wetting. Increasing temperature enhanced permeate flux but reduced PFAS rejection, especially for short-chain compounds, indicating a trade-off between productivity and selectivity. Leachate age noticeably influenced membrane fouling behavior, transitioning from organic cake fouling in YLFL to inorganic carbonate scaling in ALFL, with corresponding shifts in flux decline patterns, membrane surface chemistry, and wettability. These findings demonstrate that PFAS compositional evolution with landfill age is a critical determinant of MD separation performance.