PFAS-driven modulation of algal organic matter enhances dissolved organic matter reactivity and disinfection by-product formation: mechanistic elucidation via multi-spectroscopic analysis, and mitigation by coagulation and nanofiltration
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
The quality of drinking water is crucial for public health and sustainable development. This study elucidates the interaction between per- and polyfluoroalkyl substances (PFAS) and algal organic matter (AOM) in freshwater sources, which modifies the composition and reactivity of dissolved organic matter (DOM), enhances the formation potential of disinfection by-products (DBP), and may impact drinking water treatment (DWT) systems. The study employs multi-spectroscopic analysis like excitation emission matrix-parallel factor analysis (EEM-PARAFAC), Fourier-transform infrared spectroscopy (FTIR), and DBP quantification to demonstrate that specific PFAS (hexafluoropropylene oxide dimer acid (GenX), and perfluorobutane sulfonate (PFBS)) with AOM shift DOM to protein-like dominance, reducing the humification index (HIX) by 70 % and disrupting amide I bonds. This transition elevated brominated DBPs (>90 % of total DBPs in algae-PFAS systems). Coagulation (Polyaluminum chloride, PACl, 50–200 mg/L) exhibited concentration-dependent flocculation index (FI) increases, with GenX (1 μg/L) and PFBS (10 μg/L) peaking at 1.1–1.18 % FI, enhancing floc formation within 300 s, though AOM reduced baseline FI to 0.7 %. Nanofiltration (NF-270 membrane) showed flux reductions of 36–43 % for GenX (0.1–10 μg/L) and 39–47 % for PFBS (0.1–10 μg/L) without AOM, intensifying to 46 % (GenX10) and 52 % (PFBS10) with AOM due to biopolymer release and algal stress. Combined coagulation and nanofiltration treatment reduced DBP precursors by 60–85 % and mitigated fouling. These findings reveal that PFAS-AOM complexes elevate DBP formation risks and impair DWT efficiency, emphasizing the need for integrated coagulation, filtration, and nanofiltration processes to manage water quality hazards arising from PFAS-algal-impacted water sources.
Date Issued
2026-02-15
Date Acceptance
2026-02-01
Citation
Journal of Hazardous Materials, 2026, 504
ISSN
0304-3894
Publisher
Elsevier BV
Journal / Book Title
Journal of Hazardous Materials
Volume
504
Copyright Statement
Copyright © 2026 Elsevier B.V. This is the author’s accepted manuscript made available under a CC-BY licence in accordance with Imperial’s Research Publications Open Access policy (www.imperial.ac.uk/oa-policy)
License URL
Publication Status
Published
Article Number
141343
Date Publish Online
2026-02-02