Mercury Removal from Aqueous Solution Using ETS-4 in the Presence of Cations of Distinct Sizes
| Autor: | Carlos M. Silva, Cláudia B. Lopes, Simão P. Cardoso, Inês Portugal, Eduarda Pereira, Tiago L. Faria |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
mercury
Metal ions in aqueous solution Sodium Analytical chemistry chemistry.chemical_element 02 engineering and technology ion exchange 010501 environmental sciences lcsh:Technology 01 natural sciences Isothermal process Article Ion TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY Mass transfer tetrapropylammonium hydroxide General Materials Science lcsh:Microscopy lcsh:QC120-168.85 0105 earth and related environmental sciences Aqueous solution lcsh:QH201-278.5 Ion exchange ETS-4 lcsh:T 021001 nanoscience & nanotechnology chemistry lcsh:TA1-2040 kinetics lcsh:Descriptive and experimental mechanics Mass action law lcsh:Electrical engineering. Electronics. Nuclear engineering lcsh:Engineering (General). Civil engineering (General) 0210 nano-technology lcsh:TK1-9971 |
| Zdroj: | Materials Volume 14 Issue 1 Materials, Vol 14, Iss 11, p 11 (2021) |
| ISSN: | 1996-1944 |
| Popis: | The removal of the hazardous Hg2+ from aqueous solutions was studied by ion exchange using titanosilicate in sodium form (Na-ETS-4). Isothermal batch experiments at fixed pH were performed to measure equilibrium and kinetic data, considering two very distinct situations to assess the influence of competition effects: (i) the counter ions initially in solution are Na+ and Hg2+ (both are exchangeable) (ii) the initial counter ions in solution are tetrapropylammonium (TPA+) and Hg2+ (only Hg2+ is exchangeable, since TPA+ is larger than the ETS-4 micropores). The results confirmed that ETS-4 is highly selective for Hg2+, with more than 90% of the mercury being exchanged from the fluid phase. The final equilibrium attained under the presence of TPA+ or Na+ in solution was very similar, however, the Hg2+/Na+/ETS-4 system in the presence of Na+ required more 100 h to reach equilibrium than in the presence of TPA+. The Hg2+/Na+/ETS-4 system was modelled and analyzed in terms of equilibrium (mass action law) and mass transfer (Maxwell&ndash Stefan (MS) formalism). Concerning equilibrium, no major deviations from ideality were found in the range of studied concentrations. On the other hand, the MS based model described successfully (average deviation of 5.81%) all kinetic curves of mercury removal. |
| Databáze: | OpenAIRE |
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