Advanced Oxidation Process for Degradation of Carbamazepine from Aqueous Solution: Influence of Metal Modified Microporous, Mesoporous Catalysts on the Ozonation Process

Carbamazepine (CBZ), a widely used pharmaceutical compound, is one of the most detected drugs in surface waters. The purpose of this work was to identify an active and durable catalyst, which, in combination with an ozonation process, could be used to remove CBZ and its degradation products. It was found that the CBZ was completely transformed after ozonation within the first minutes of the treatment. However, the resulting degradation products, 1-(2-benzaldehyde)-4-hydro-(1H,3H)-quinazoline-2-one (BQM) and 1-(2-benzaldehyde)-(1H,3H)-quinazoline-2,4-dione (BQD), were more resistant during the ozonation process. The formation and degradation of these products were studied in more detail and a thorough catalytic screening was conducted to reveal the reaction kinetics of both the CBZ and its degradation products. The work was performed by non-catalytic ozonation and with six different heterogeneous catalysts (Pt-MCM-41-IS, Ru-MCM-41-IS, Pd-H-Y-12-EIM, Pt-H-Y-12-EIM, Pd-H-Beta-300-EIM and Cu-MCM-41-A-EIM) operating at two temperatures 20 degrees C and 50 degrees C. The influence of temperature on degradation kinetics of CBZ, BQM and BQD was studied. The results exhibited a notable difference in the catalytic behavior by varying temperature. The higher reactor temperature (50 degrees C) showed a higher activity of the catalysts but a lower concentration of dissolved ozone. Most of the catalysts exhibited higher removal rate for BQM and BQD compared to non-catalytic experiments in both temperatures. The Pd-H-Y-12-EIM catalyst illustrated a higher degradation rate of by-products at 50 degrees C compared to other catalysts

Synthesis of carbonated vegetable oils: Investigation of microwave effect in a pressurized continuous-flow recycle batch reactor

International audienceWith the depletion of fossil resources, it is essential for the chemical industry to find alternative raw materials for polymers. Polyurethanes can be synthesized from vegetable oils and CO2 via an environmentally friendly, non-isocyanate pathway. Carbonation of epoxidized vegetable oil is a key step allowing the feasibility of this method. Because it requires a high temperature, high pressure and long reaction time to achieve complete conversion, microwave technology (MW) is an interesting approach for the intensification of the carbonation process. However, MW-irradiated batch reactor has multiple issues regarding scale-up. A microwave irradiated continuous-flow recycle batch reactor which can operate at high temperature (130 °C) and moderate pressure (8 bar) was used in the present work. The effect of microwave irradiation on the kinetics of carbonation reaction was studied. A kinetic model was developed to compare quantitatively the performance under microwave and conventional heating (CH). It was found that the activation energy of the carbonation reaction was slightly lower with the use of MW irradiation, where the values for CH and MW are respectively 0.385E + 04 J/mol and 0.338E + 04 J/mol