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Título: | Fluorine adsorption on floating iron nanoparticles confined to gigaporous structure of large adsorbent water spheres |
Palavras-chave: | Nanoadsorbents Large hydrogel spheres Sol-gel process Defluoridation Wastewater treatment |
Data do documento: | Nov-2021 |
Citação: | OLIVEIRA, F. W. F. de et al. Fluorine adsorption on floating iron nanoparticles confined to gigaporous structure of large adsorbent water spheres. Environmental Technology & Innovation, [S.l.], v. 24, Nov. 2021. |
Resumo: | Effective defluoridation of artesian well water can be performed with iron nanoparticles confined to expanded reticulated polymer network of polyvinyl alcohol (PVA) containing a high quantity of water. For this purpose, large (3433 ± 63 m) adsorbent water spheres, meaning spheres containing Fe2O3 (15.8 wt%)-PVA (8.2 wt%)-O (76.0 wt%), were manufactured (sol–gel process) and characterized (TG/DTA, XRD, MÖSSBAUER, SEM/EDS, BET, FTIR, and XPS). In the resulting spongy water spheres, gigapores (140,000 nm) were filled with loosely agglomerated and floating naked nanoparticles (<20 nm) of octahedral [Fe2O2(HO)8] and/or [Fe2O3(HO)6]0 complexes without prejudice to the chemical and mechanical (35.0 ± 0.4 kPa) stability of the nanostructured adsorbent. The built-in mesoporous and gigaporous structure provided good pore connectivity, which significantly reduced the adsorption rate limitation imposed by boundary-layer and intraparticle diffusion effects as well as it has enhanced the adsorptive capacity (from 77.9 to 204.9 mgF/g) of the referred adsorbent water spheres. XPS proved the chemical interaction mechanism in F–Fe–PVA–HO system. Fluoride chemisorption occurs on PVA (marginally; (-CH2CHF-), (-CH2CF2-), and (-CF2CF2-)) and Fe (predominantly; octahedral Fe2F5.7H2O complex) particles. Adsorbent water spheres can defluorinate natural waters in multiple adsorption cycles in fixed bed columns after fluorine desorption with NH4OH. |
URI: | https://www.sciencedirect.com/science/article/pii/S235218642100643X http://repositorio.ufla.br/jspui/handle/1/50531 |
Aparece nas coleções: | DFI - Artigos publicados em periódicos |
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