| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 230884 | The Journal of Supercritical Fluids | 2013 | 7 Pages |
The purpose of this study was to efficiently regenerate activated carbons (ACs) saturated with phenol using supercritical water at 260 bar and 400–500 °C. Regeneration temperature and time were the variables that most affected the process. Times close to 10 min provided efficiencies of 100%, such that the procedure can be considered to be very fast and efficient.A study of temperature-programmed desorption using liquid and supercritical water as the carrier fluid indicated that a fraction of the phenol retained on the ACs was physisorbed while another fraction was chemisorbed. ACs subjected to successive cycles of adsorption–regeneration were not completely regenerated when the regeneration times were short (3 min). The study also addressed the regeneration of ACs saturated with phenol aged over long periods of time (0.5–60 days). The difficulty in regenerating the ACs increased with the saturation of phenol and the ageing time.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Regeneration of ACs with phenol by using supercritical water is fast and efficient. ► Temperature and time are the most important parameters in the removal of phenol. ► Phenol is physi- and chemisorbed on the surface of the ACs. ► ACs saturated with aged phenol are difficult to regenerate. ► Textural characteristics and pH of the ACs increase slightly with regeneration.
