Optimizing Methyl Orange Degradation via Electro-Fenton with Copper Foam Cathode: A Comparative Approach Using Iron Waste vs. Iron Salts and Exploring Catalyst and Cathode Durability

The use of foam electrodes as a cathode has proven its efficiency in wastewater treatment. In this study, methyl orange (MO) was treated by Electro-Fenton technology (EFT) using a copper foam (Cf) as a cathode. EFT was an advanced strategy for MO degradation, which accomplished excellent degradation efficiency (%ReMO) exceeded 98% over 35 min treatment period at prime conditions using 0.124 mM of iron salts (FeSO4.7H2O), 0.3 LPM of air flow, 0.2 mA/cm2 of current density (CD), and initial pH of 3.0. The outcomes showed that the air flow rate had the main impact on the %ReMO. Furthermore, the contribution of anodic oxidation (AO) to dye removal was investigated to distinguish its role relative to the EFT mechanism, revealing that the MO degradation was government by EFT. Additionally, iron waste (IW) demonstrated high efficacy as a heterogeneous electro-Fenton catalyst, with both the IW and Cf cathode exhibiting excellent reusability and stability. These findings highlight the potential for integrating sustainable materials and processes in dye removal applications, advancing both efficiency and cost-effectiveness.