Improvement of electro-Fenton process by using heterogeneous Fe-MIL-88B nanocatalyst and simultaneous rotation of cathode and anode for dye removal.

In this study, improvement of the electro-Fenton process using Fe-MIL-88B along with the innovation in the reactor with the simultaneous rotation of the cathodes and anodes was carried out to remove Acid Blue 25. For this purpose, the Fe-MIL-88B nanocatalyst was synthesised by the thermal solvent method and was characterised by FT-IR, EDAX, XRD, and FESEM. For the experiments, an electrochemical cell with a useful volume of 1 L and rotating cathodes and anodes were used and nanoparticles were added to the system as a slurry. To determine the appropriate values of the effective parameters, the OFAT method was used. According to the results, 0.3 g/L Fe-MIL-88B, pH equal to 3, dye concentration of 75 mg/L, a current intensity of 0.228 A, and a rotation velocity of 100 rpm were chosen as suitable values for the process. In optimal conditions, the dye removal efficiency reached to 92.3% after 90 min, which resulted in a 14.5% improvement in the dye removal efficiency compared to the conventional process under the same conditions. Also, after 90 min, the removal efficiencies of 77.08 and 63.63% were obtained for COD and TOC, respectively. The results indicated acceptable decomposition of the effluent into less hazardous compounds.