Advanced oxidation process for the removal of ibuprofen from aqueous solution: A non-catalytic and catalytic ozonation study in a semi-batch reactor

“The Concern on the availability of clean and safe fresh water and the quality of recycled wastewater are important issues, which require a suitable technology to restore the water quality. Pharmaceuticals in waste water are not easily degraded by conventional water treatment technology. Advanced oxidation processes have been applied to eliminate traces of these compounds from aquatic environments. This study was focused on the degradation of ibuprofen (IBU) in aqueous solutions by catalytic and non-catalytic ozonation. Preliminary experiments were conducted to optimize the ozone concentration in water and to investigate other operation parameters. The operation parameters were: temperature, stirring rate, gas flow rate, pH, and use of Spinchem stirrer to reach higher concentrations of dissolved ozone. In general, the initial concentration of IBU was 10 mg/L, and about 93% of IBU was degraded after 4 h of ozonation under optimal conditions. Additional experiments were carried out to investigate the benefit of applying a solid catalyst. H-Beta and Fe-H-Beta type catalysts were immobilized in the Spinchem rotating bed device. The catalytic experiments illustrated a significant improvement in the degradation rate of IBU. The catalysts were characterized by nitrogen adsorption- desorption, scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction and FTIR.”

Highlights:

• “The effect of different stirrer types on the dissolved ozone concentration was investigated. A normal four-blade stirrer and Spinchem rotating bed stirrer were used in these experiments. The comparison in Fig. 8 illustrates that the ozone concentration was significantly higher (40%) with the Spinchem stirrer, i.e., 4.15 mg/L at maximum 1070 rpm vs 2.95 mg/L.”
• “These experiments also confirmed that the stirring speed did not influence significantly the ozone concentration within the range of 450–1070 rpm.”
• Degradation of the pharmaceutical compound ibuprofen by ozone, was optimized in batch type reactors with and without zeolite based heterogeneous catalysts. The rotating bed reactor technology increased the concentrations of dissolved gas compared to traditional stirred tank reactors and allowed convenient handling of the catalyst particles without any filtration.