LAUSR

Abstract The use of chemical pesticides in agriculture to increase the quantity and quality of crops ultimately leads to pollution of water and soil resources. The evaluation of parameters that can affect the efficiency of three-dimensional sono-electro-Fenton (3D/SEF) with PAC/Fe3O4 particle electrodes using and SS316/β-PbO2 anode in 2,4-D degradation, and those parameters were optimized by Taguchi design technique. Different analyses (i.e., Field emission scanning electron microscopy (FESEM), X-ray diffraction analysis (XRD), energy-dispersive X-ray spectroscopy mapping (EDX-mapping), vibrating sample magnetometer (VSM), and Fourier Transform Infrared Spectroscopy (FTIR)) could approve the fruitful synthesis of PAC/Fe3O4 and SS316/β-PbO2 anode. By employing LC-MS analysis, the intermediates generated from pollutant degradation were spotted, and degradation pathways was proposed. The pH of the solution (with percentage contribution of up to 39.52%) was as the most effective independent variable on system response. The optimal conditions for removal of 2,4-D were determined to be as follows: 2,4-D concentration= 50 mβL, pH= 3; FeSO4= 0.08 mg/250 mL, electrolysis time= 60 min, H2O2 concentration= 0.2 mL/L, current density= 5 mA/cm2, catalyst dose= 5 g/L, and Na2SO4 concentration= 0.3 g/250 mL; in these conditions, removal efficiencies of the 2,4-D, COD and TOC were 96.2%, 92.31% and 86.5%, respectively. Moreover, significant reduction was detected in the biological toxicity of the outlet effluent from the 3D/SEF process. Finally, 2,4-D herbicide was completely degraded using hydroxyl radicals produced by the electrocatalytic process and converted into CO2 and H2O products. Considering obtained results, the wastewater containing pesticides such as 2,4-D herbicide can effectively treated by 3D/SEF process, and it could offer acceptable results.