Synthesis, characterization, and in-situ H2O2 generation activity of activated Carbon/Goethite/Fe3O4/ZnO for heterogeneous electro-Fenton degradation of organics from woolen textile wastewater

Developing effective and highly stable Heterogeneous electro-Fenton (HEF) catalysts for removing organic pollutants from aquatic environments is a challenge in the scientific world. In this study, activated carbon/Goethite/Fe3O4/ZnO was synthesized as a novel eco-friendly and economic HEF catalyst to remove chemical oxygen demand (COD) from woolen textile wastewater (WTW). According to characterization analyses, the catalyst was in a polycrystalline structure, had good stability (-34.53 mV), and had an average pore diameter was 8.017 nm. According to catalytic activity results, COD removal by anodic oxidation (AO) was 44.29%, AO-H2O2 was 58.99%, and adsorption was 18.5%. ⋅OH and ⋅O2– responsible for COD removal with 76.21% and 28.07%. The low p-value (<0.0001), high F-value (456.90), high Adeq. the precision value (76.74) and high R2 (0.9977) of the model show that the established quadratic model is significant, valid, successful in estimating data, and reliable in navigating design space. Optimal conditions were determined as aeration rate: 2.86 L/min, current density: 5.38 mA/cm2, catalyst dose: 0.194 g/L, reaction time: 85.41 min. COD removals were determined experimentally and theoretically as 96.39% and 98.66%. The total cost was $ 1.75 to remove 1 kg COD from WTW. The synthesized catalyst showed good performance over five cycles (82%), suggesting its use on an industrial scale.