Aqueous nitrate ion adsorption/desorption by olive solid waste-based carbon activated using ZnCl2
| Autor: | Ahed Zyoud, Heba Nassar, Hikmat S. Hilal, Rafeeq Tanbour, Amer El-Hamouz, Nour Halayqa |
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| Rok vydání: | 2020 |
| Předmět: |
Langmuir
Aqueous solution 010405 organic chemistry Inorganic chemistry Pharmaceutical Science chemistry.chemical_element Management Monitoring Policy and Law 010402 general chemistry 01 natural sciences Pollution 0104 chemical sciences chemistry.chemical_compound Adsorption Nitrate chemistry Specific surface area Desorption medicine Environmental Chemistry Carbon Activated carbon medicine.drug |
| Zdroj: | Sustainable Chemistry and Pharmacy. 18:100335 |
| ISSN: | 2352-5541 |
| Popis: | ZnCl2 activated carbon (ZnCl2-AC, with specific surface area ~1480 m2/g) effectively adsorbs nitrate from water with uptake capacity (~5.5 mg/g) four-fold that for other commercial activated carbons (CACs). Kinetics show a small activation energy value (~7 kJ/mol) consistent with a diffusion-controlled process. This is further confirmed by intra-particle diffusion study. Negative thermodynamic parameters (ΔH° −13.859 kJ/mol, ΔS° −43.8 J/mol K, and ΔG° −0.808 kJ/mol) indicate spontaneous nitrate adsorption. The high specific surface area rationalizes the high uptake capacity for the ZnCl2-AC. A Langmuir type adsorption, is observed. ZnCl2-AC effectively adsorbs the nitrate from water, even at high concentrations, and brings the concentration to allowed maximum values. Despite these advantages, the ZnCl2-AC exhibits low desorption (~20%) of pre-adsorbed nitrate ions into concentrate solutions. Up to ~40% desorption is observed by grinding the pre-saturated ZnCl2-AC. Developing other methods to completely recover the adsorbed nitrate and the adsorbent for multiple use is needed. |
| Databáze: | OpenAIRE |
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