Catalytic oxidation of phenol adsorbed on Cu/AC and Fe/AC catalyst-sorbents

Catalytic dry oxidation of phenol adsorbed on activated carbon (AC) supported metal catalyst-sorbent (metal/AC) is promising for phenolic wastewater treatment. The process consists of adsorption of phenol on the catalyst-sorbent in a fixed-bed reactor for a long period of time and catalytic dry oxidation of phenol adsorbed upon the discharge of water from the adsorption bed in a short period of time. In this work, TG/MS instrument was used to investigate the catalytic activity and ignition behavior of Cu/AC and Fe/AC catalyst-sorbents by temperature-programmed oxidation technique, and the influences of metal component and AC type on the performance of the metal/AC catalyst-sorbent were mainly discussed. The result indicated that both Cu/AC and Fe/AC showed high activity for catalytic oxidation of phenol, and Cu/AC was more active than Fe/AC, which showed high conversion of phenol and no production of phenol and benzene. The initial oxidation temperature of phenol was ca. 200 degrees C, and the ignition temperature of AC was about 130 degrees C higher than the initial phenol oxidation temperature. The difference in oxidation activity among the metal/AC catalyst-sorbents could be attributed to the differences of metal components, activated carbon, and the interaction between the metal and support. The test of eight adsorption-oxidation cycle of phenol on Cu/AC showed that its adsorption capacity decreased to an asymptotic level of about 70 mg/g with the increase of adsorption-regeneration cycle, which suggested that a steady state adsorption capacity could be reached.