Heterogeneous Catalytic Degradation of Diuron Using Algerian Sodium Montmorillonite

Diuron is categorized as a probable human carcinogen by the United States Environmental Protection Agency (EPA). This work is aimed to determine the optimal conditions for the catalytic degradation of Diuron in an aqueous solution with H2O2 using Algerian sodium Montmorillonite (Mont-Na) as the catalyst. The material is characterized before and after the experiment using X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, specific surface area (S-BET), elemental analysis, and thermal analysis (TGA/DTA). The surface charge is determined by measuring the point of zero charge. Tests with H2O2 without Mont-Na provide a 32% conversion rate after 8 h. However, a mixture of 1 g Mont-Na and H2O2 increases the conversion rate to 91% after 180 min at 25 degrees C and pH 6.3. The Diuron disappearance is evidenced by high-performance liquid chromatography using a UV-vis detector (HPLC/UV-vis). Specifically, 3,4-dichloroaniline (DCA) is the only by-product. At the basic pH values 9 and 11, a conversion rate of 72.5% is achieved with a lower contact time of 150 min. A change in temperature toward higher values results in a decrease in the degradation rate. Overall, Algerian sodium Montmorillonite is used successfully for the heterogeneous catalytic degradation of Diuron from polluted water.

Automated summary

This study aimed to optimize the catalytic degradation of Diuron in an aqueous solution using Algerian sodium Montmorillonite as the catalyst with H2O2. Results showed that a mixture of Mont-Na and H2O2 significantly increased the degradation rate of Diuron at 25 degrees C and pH 6.3, with 3,4-dichloroaniline as the only by-product.