Catalytic Ozonation of Phenol Using Copper Coated Pumice and Zeolite as Catalysts

Background: Catalytic ozonation has recently been applied as a new method of contaminant removal from water and wastewater. In this study, copper coated pumice and zeolite were used to catalyze the ozonation of phenol as a target pollutant from aqueous solutions. Methods: The pumice and zeolite stone were modified by CuSO4 (1N). Modified pumice and zeolite were characterized by Adsorption/Desorption Porosimetry (BET) and Scanning Electron Microscope analyses. Ozonation and catalytic ozonation experiments were performed in a 1 L semi-batch reactor containing a prepared phenol solution. The efficiency of catalytic ozonation was investigated by different variables: pH value, contact time, initial phenol concentration, catalyst dose, and radical scavenger. Results: Experimental data indicated that as the pH solution increased, phenol removal increased. pH = 8 was measured as the optimum pH. The removal efficiency in single ozonation process (SOP) was 32% and in the catalytic ozonation process (COP) using modified zeolite and pumice was 51% and 63%, respectively. Moreover, these processes showed a great ability to mineralize phenol (up to 30%). Using the radical scavenger determined the indirect oxidation as the main pathway of phenol removal in both catalytic processes. Conclusion: The copper modified zeolite and pumice had good performance to remove phenol through catalytic ozonation method.