Selenite sorption onto goethite: isotherm and ion-competitive studies, and effect of pH on sorption kinetics
| Autor: | Eva Duborská, Martin Cesnek, Marcel B. Miglierini, Michaela Matulová, Martin Urík, Marek Bujdoš |
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| Rok vydání: | 2019 |
| Předmět: |
Goethite
General Chemical Engineering Inorganic chemistry chemistry.chemical_element 02 engineering and technology 010402 general chemistry 01 natural sciences Biochemistry Chloride Industrial and Manufacturing Engineering chemistry.chemical_compound symbols.namesake Reaction rate constant Materials Chemistry medicine Langmuir adsorption model Sorption General Chemistry 021001 nanoscience & nanotechnology Phosphate 0104 chemical sciences chemistry visual_art symbols visual_art.visual_art_medium Ferric 0210 nano-technology Selenium medicine.drug |
| Zdroj: | Chemical Papers. 73:2975-2985 |
| ISSN: | 1336-9075 2585-7290 |
| Popis: | Sorption of oxyanions onto ferric oxyhydroxides’ surfaces is naturally occurring process with advantageous implications in remediation of contaminated waters or management of landfills. Therefore, this paper provides information on selenite sorption onto goethite, which is one of the most common oxyhydroxides in the environment. Our results showed that selenite sorption was well described by the pseudo-second-order kinetic model, as well as by Langmuir isotherm. This suggests chemisorption as a rate-controlling step and formation of selenite monolayer on goethite surface with relatively high 83.8 µmol g−1 maximum sorption capacity at pH 3, which was determined for initial selenite concentration in the range of 45–550 µmol L−1 in 0.5 g L−1 (m/v) goethite suspension. The Mossbauer analysis revealed only marginal structural changes in goethite during sorption. Our results also showed that pH significantly affects the overall sorption rate constant with the highest values at the acidic region. Study on competitive sorption behaviour highlighted significant influence of phosphate on selenite sorption. There was no competition for sorption positions with excessive concentrations of sulphate and chloride ions. However, equimolar concentrations of sulphate and chloride led to changes in selenite sorption efficiency. Our results showed that selenite sorption onto goethite is a viable method for selenite removal and, thus, goethite can be successfully applied as a component in commercial composite sorbents or in geochemical barriers. |
| Databáze: | OpenAIRE |
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