Regeneration of Modified Bentonite Loaded with Phenol Using Supercritical Fluids

• Main Authors: Uğur Salgın, Nuray Yıldız, Ayla Çalımlı
• Format: Article
• Language: English
• Published: Hindawi - SAGE Publishing 2004-02-01
• Series: Adsorption Science & Technology
• Online Access: https://doi.org/10.1260/026361704323150980

The desorption of phenol from organically modified bentonite (ODTMA–bentonite) using supercritical fluids was studied. Parameters such as pressure, temperature, supercritical fluid flow rate and co-solvent (entrainer) concentration were investigated. The maximum desorption of phenol (ca. 98 w/w%) using supercritical CO 2 (SC CO 2 ) was obtained by operating at 500 bar, 353 K and 3.33 × 10 −8 m 3 SC CO 2 /s. In the presence of ethanol as a co-solvent (10 v/v%), the maximum desorption of phenol attained a value of 97 w/w% using supercritical CO 2 at low temperature (313 K) and pressure (300 bar) and a high supercritical fluid flow rate (3.33 × 10 −8 m 3 SC CO 2 /s). In addition, the results showed that the regenerated ODTMA–bentonite retained its adsorption power towards phenol even after several regeneration cycles. It was therefore concluded that exhausted/used organobentonites might be regenerated via processes involving supercritical fluid extraction.