Degradation of pollutants in water by Fenton-like oxidation over LaFe-catalysts: Optimization by experimental design

The effect of different parameters such as temperature, type of catalyst and hydrogen peroxide (H2O2) con-centration on the degradation of pollutants in water by Fenton-like oxidation was studied by using the Box-Behnken design (BBD), an effective statistical model to design the experiments. Concerning the heterogeneous catalysts, three bimetallic catalysts with lanthanum (La) and iron (Fe) ion-exchanged into zeolites (NaY and ZSM5) and a natural clay from Morocco were prepared and used for Fenton-like oxidation of organic pollutants in water. Tartrazine (Tar, a food coloring compound known as E102) and caffeine (Caf, a stimulant drug present in popular beverages such as coffee and tea) were selected as pollutants due to their presence in several com-mercial products for daily consumption. The BBD model indicated that the optimum catalytic conditions for Fenton-like reaction with an initial pollutant concentration of 30 ppm at pH 3.0 were T = 40 degrees C and 90 mM of H2O2. The maximum conversion values achieved with the best catalyst, LaFeZSM5, were 96.6% for Tar after 180 min and 51.0% for Caf after 300 min of reaction. To increase the conversion of Caf, a modified zeolite electrode was used for electro Fenton-like oxidation without H2O2, at room temperature.

Automated summary

The effect of different parameters on the degradation of pollutants in water by Fenton-like oxidation was studied using the Box-Behnken design. Three bimetallic catalysts were prepared and used for Fenton-like oxidation of organic pollutants in water. The optimal catalytic conditions were found to be a temperature of 40 degrees C and an H2O2 concentration of 90 mM, resulting in high conversion rates for Tar and Caf.