Degradation of phenol by heterogeneous Fenton reaction using Fe/clinoptilolite

Abstract

A novel heterogeneous catalyst for degradation of phenol has been synthesized. Dispersed metallic clusters of iron loaded on to clinoptilolite by impregnation method. Clinoptilolite belongs to the broad family of natural zeolites. The influences of pH, the mass ratio of iron to clinoptilolite, the ratio of hydrogen peroxide to phenol and catalyst loading on phenol degradation were investigated. An autocatalytic heterogeneous–homogeneous kinetic model was proposed for this reaction. Experiments were performed, using a stirred batch reactor under mild conditions with 100mgL−1 initial phenol concentration applying Fe/clinoptilolite as a catalyst and H2O2 as an oxidant. This new heterogeneous Fenton-like system resulted in a nearly total elimination of phenol and 70% COD removal during 30min. In order to examine the effect of run time on the activity and stability of the catalyst, the degradation reaction was carried out applying a continuous packed bed reactor. It was observed that during 30h time on stream no change in the activity of the catalyst or any structural deformation of the particles was occurred. A negligible release of iron from the catalyst during the reaction (6ppm) may be related to the appropriate stability of the latter.