Sorption–desorption of antimony species onto calcined hydrotalcite: Surface structure and control of competitive anions
| Autor: | Juliana Nunes Quirino, Alexandre Urbano, Leonel Vinicius Constantino, Maria Josefa Santos, Taufik Abrão, P. S. Parreira |
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| Rok vydání: | 2018 |
| Předmět: |
Environmental Engineering
Health Toxicology and Mutagenesis Inorganic chemistry Antimonite chemistry.chemical_element 02 engineering and technology 010501 environmental sciences complex mixtures 01 natural sciences symbols.namesake chemistry.chemical_compound Antimony Desorption Environmental Chemistry Waste Management and Disposal 0105 earth and related environmental sciences Hydrotalcite Ion exchange Langmuir adsorption model Sorption 021001 nanoscience & nanotechnology Pollution chemistry symbols 0210 nano-technology Antimonate |
| Zdroj: | Journal of Hazardous Materials. 344:649-656 |
| ISSN: | 0304-3894 |
| Popis: | Calcined hydrotalcite can be applied to remove anionic contaminants from aqueous systems such as antimony species due to its great anion exchange capacity and high surface area. Hence, this study evaluated antimonite and antimonate sorption-desorption processes onto calcined hydrotalcite in the presence of nitrate, sulfate and phosphate. Sorption and desorption experiments of antimonite and antimonate were carried out in batch equilibrium and the post-sorption solids were analyzed by X-ray fluorescence (EDXRF). Sorption data were better fitted by dual-mode Langmuir-Freundlich model (R2>0.99) and desorption data by Langmuir model. High maximum sorption capacities were found for the calcined hydrotalcite, ranging from 617 to 790meqkg-1. The competing anions strongly affected the antimony sorption. EDXRF analysis and mathematical modelling showed that sulfate and phosphate presented higher effect on antimonite and antimonate sorption, respectively. High values for sorption efficiency (SE=99%) and sorption capacity were attributed to the sorbent small particles and the large surface area. Positive hysteresis indexes and low mobilization factors (MF>3%) suggest very low desorption capacity to antimony species from LDH. These calcined hydrotalcite characteristics are desirable for sorption of antimony species from aqueous solutions. |
| Databáze: | OpenAIRE |
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