Publication Details |
| Category | Text Publication |
| Reference Category | Journals |
| DOI | 10.1016/j.envpol.2025.126796 |
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| Title (Primary) | Mesoporous silica nanoparticles for rapid removal of PFOA: Impact of surface functional groups on adsorption efficiency and adsorbent regeneration |
| Author | Abdelsamad, A.M.A.; Saeidi, N.; Mackenzie, K.
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| Source Titel | Environmental Pollution |
| Year | 2025 |
| Department | TECH |
| Volume | 383 |
| Page From | art. 126796 |
| Language | englisch |
| Topic | T7 Bioeconomy |
| Supplements | https://ars.els-cdn.com/content/image/1-s2.0-S0269749125011698-mmc1.docx |
| Keywords | Perfluorooctanoic acid (PFOA); Mesoporous silica nanoparticles (MSN); Adsorption kinetics; Surface functionalization; Adsorbent regeneration |
| Abstract | This study explores mesoporous silica nanoparticles (MSN) synthesized via oil-water biphase stratification and functionalized with n-octyltrichlorosilane (OTS), 3-aminopropyltriethoxysilane (APTES), or both, yielding OMSN, AMSN, and OAMSN. All adsorbents rapidly removed perfluorooctanoic acid (PFOA) from water, reaching 95% adsorption equilibrium within 10 minutes. PFOA adsorption kinetics showed that OAMSN, with the largest pore size (14.4 nm), had the highest pseudo-second-order rate constant. Isotherm analysis indicated that both OAMSN and AMSN achieved higher equilibrium loadings across a broad equilibrium concentration range (Ce: 0.2 μg/L - 8 mg/L), which covers environmentally relevant concentration of PFOA. AMSN, with a positively charged surface (point of zero charge = 9), showed the highest maximum adsorption capacity (qm = 208 mg/g), while OAMSN, combining hydrophobicity and positive charge, achieved a much higher adsorption coefficient (Kd = 1.4 × 105 L/kg at Ce = 50 μg/L). OMSN, the most hydrophobic evaluated by water contact angel measurements, had a high Kd at Ce = 50 μg/L but the lowest qm. Pore filling calculations showed large variations (0.8% for MSN to 12% for AMSN) despite similar pore volumes, highlighting the dominant role of surface chemistry over pore structure. Hydrophobicity governs adsorption at low loadings, while electrostatic interactions become key approaching qm. Solvent extraction preserved adsorption efficiency in hydrophobic adsorbents (OMSN, OAMSN), while UV-activated persulfate degraded up to 87% of the loaded PFOA but impaired reuse, especially for functionalized materials. Thus, solvent extraction suits functionalized adsorbents, whereas UV/persulfate is better for regenerating non-functionalized ones. |
| Persistent UFZ Identifier | https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=31006 |
| Abdelsamad, A.M.A., Saeidi, N., Mackenzie, K. (2025): Mesoporous silica nanoparticles for rapid removal of PFOA: Impact of surface functional groups on adsorption efficiency and adsorbent regeneration Environ. Pollut. 383 , art. 126796 10.1016/j.envpol.2025.126796 |
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