Synthesis of calcium–aluminum-layered double hydroxide and a polypyrrole decorated product for efficient removal of high concentrations of aqueous hexavalent chromium
| Autor: | Jing Li, Yan Chen, Xuguang Li, Wen Song, Dan Yang, Liangguo Yan, Yanfei Li |
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| Rok vydání: | 2022 |
| Předmět: |
Chromium
Polymers Aluminum Hydroxide Polypyrrole Calcium Hydroxide Biomaterials symbols.namesake chemistry.chemical_compound Colloid and Surface Chemistry Adsorption Specific surface area Pyrroles Hexavalent chromium Aqueous solution Ion exchange Chemistry Langmuir adsorption model Surfaces Coatings and Films Electronic Optical and Magnetic Materials Kinetics symbols Hydroxide Calcium Water Pollutants Chemical Aluminum Nuclear chemistry |
| Zdroj: | Journal of Colloid and Interface Science. 607:1963-1972 |
| ISSN: | 0021-9797 |
| DOI: | 10.1016/j.jcis.2021.10.014 |
| Popis: | To efficiently remove high concentrations of hexavalent chromium (Cr(VI)), calcium–aluminum-layered double hydroxide (CaAl-LDH, denoted as CAL), and polypyrrole-modified CAL (CAL-PPy) were prepared by hydrothermal and in situ polymerization methods, respectively. The chemical structure, morphology, and elemental results indicated that the chain-like polypyrrole was decorated with hexagonal CAL. The specific surface area of CAL-PPy increased from 8.746 m2/g to 24.24 m2/g. The adsorption performances of CAL and CAL-PPy for aqueous Cr(VI) were investigated using batch equilibrium experiments. The decontamination process of aqueous Cr(VI) (100 mg/L) reached the equilibrium state within 50 min, and the kinetic data met the pseudo-second-order kinetic equation. The Langmuir model described the isothermal data properly, and the obtained theoretical adsorption capacity of CAL for Cr(VI) at 318 K was 34.06 mg/g, while that of CAL-PPy was 66.14 mg/g. The removal mechanisms involved electrostatic attraction, surface complexation, anion exchange, and reduction to low-toxicity Cr(III). Therefore, CAL and CAL-PPy have underlying applications in treating real wastewater containing Cr(VI). |
| Databáze: | OpenAIRE |
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