Département Environnement et Développement Durable, UFR - Ingénierie Agronomique, Forestière et Environnementale, Université de Man, Man, Côte d’Ivoire
The kaolinite-coating laterite (B catalysts) was used for the efficient degradation of methylene blue (MB) from aqueous solution. Heterogeneous Fenton catalytic oxidation experiments of B catalyst were investigated by changing the effective factors such as amount of laterite and amount of kaolinite. To that end, four (4) types of B catalysts were made: (i) B0 catalyst (50% kaolinite + 50% uncalcined laterite); B1 catalyst (50% kaolinite + 50% laterite calcined at 600°C), B2 catalyst (30% kaolinite + 70 % laterite calcined at 600° C) and B3 catalyst (100 % kaolinite + Iron solution from laterite). The result showed that B2 catalyst exhibits the highest performance with a MB degradation percentage (77%) after 100 min. For analyzing the performance of B2 catalyst, the effects of B2 catalyst amount, pH, and hydrogen peroxide (H2O2) were also studied at 100 min. Kinetic studies were also carried out in this experiment. The results indicated that more than 90% of decolorization was achieved with 60g of B2 catalyst at pH acidic (2 to 3). Moreover, higher MB degradation (≤ 90%) was reported at the presence of H2O2 and B2 catalyst in the reactor. However, only 14% of MB was adsorbed in the presence of H2O2 and without B2 catalyst. On the other hand, it was observed that second- order kinetics (R2>0.90) was well fitted in the MB degradation process. Considering the above, kaolinite-coating laterite (B2 catalyst) could be used as efficient, cheap, and eco-friendly catalytic oxidation material for the degradation of MB in aqueous solution.