Sorption, mechanism, and behavior of sulfate on various adsorbents: A critical review
| Autor: | Bahareh Sadeghalvad, Niyayesh Khorshidi, Amirreza Azadmehr, Mika Sillanpää |
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| Rok vydání: | 2021 |
| Předmět: |
Environmental Engineering
Polymers Health Toxicology and Mutagenesis 0208 environmental biotechnology Ionic bonding 02 engineering and technology 010501 environmental sciences 01 natural sciences Endothermic process chemistry.chemical_compound Adsorption Humans Environmental Chemistry Pyrroles Sulfate Cellulose 0105 earth and related environmental sciences Aqueous solution Sulfates Public Health Environmental and Occupational Health Sorption General Medicine General Chemistry Human decontamination Hydrogen-Ion Concentration Pollution 020801 environmental engineering Kinetics chemistry Chemical engineering Thermodynamics Water Pollutants Chemical |
| Zdroj: | Chemosphere. 263:128064 |
| ISSN: | 0045-6535 |
| Popis: | Sulfate decontamination has drawn widespread attention due to its harmful effects by broad human and animal exposure in recent decades. Adsorption is one of the most promising methods for sulfate decontamination. This review categorized various sulfate adsorbents, discussed the adsorption behavior, and introduced effective adsorbents in detail in terms of their preparation, characterization, and affecting factors on adsorption efficiency. Moreover, adsorption mechanisms of sulfate on different adsorbents are reviewed based on the intermolecular interaction, equilibrium, thermodynamic, and kinetic studies. Among natural bioadsorbents, synthesized-organic, and synthesized-inorganic adsorbents chitin-based shrimp shells (156 mg/g), bagasse pith cellulose-based (526.32 mg/g), and ZrO(OH)2/Y-Zeolite (284.22 mg/g) showed the significant capacity for sulfate uptake from aqueous solution, respectively. Although natural adsorbents have been proved to be inexpensive and efficient, they are not as popular as synthesized adsorbents for sulfate decontamination in recent years due to their low recoverability and reusability. The adsorption mechanism of sulfate to various adsorbents is generally attributed to electrostatic interactions, covalent or ionic bonding, and hydrogen bonding. Based on equilibrium studies, sulfate adsorption processes were done mainly homogeneously for most of the adsorbents; however, there are some exceptions of the heterogeneous adsorption process of sulfate, which is done mostly for adsorbents that remove sulfate through hydrogen and covalent bonding. The kinetic studies illustrated that both film diffusion and pore-diffusion could control sulfate uptake by the various adsorbents. The thermodynamic studies showed that the sulfate adsorption is endothermic and spontaneous except for the sulfate removal by polypyrrole-modified activated-carbons and LDH-HPI mine waste, which requires energy for adsorption. |
| Databáze: | OpenAIRE |
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