Coupling of the optimized electro-Fenton-like process with pulsed laser ablation method to produce bimetallic nanoparticles of Fe°/Cu° and Fe°/Zn° in treatment of thiophene aqueous samples

Abstract

In this study, an electro-Fenton-like method in the presence of iron particles was used for degradation of toxic thiophene pollutant from aqueous samples with performance > 99%. In an electrolytic reactor, the effect of current density, H2O2 dosage and pH of the sample on the treatment efficiency was investigated and optimized using response surface method in experimental design methodology. The conditions were optimized in current density 20 mA/cm2, H2O2 dosage 500 ppm and pH = 3.0. In this process, a laser pulse ablation was used to produce iron nanoparticles in the electro-Fenton reactor to decrease the treatment time. Also, two bimetallic iron-copper and iron-zinc were used to investigate the synergistic effect of bimetallic catalyst on degradation efficiency of thiophene. The removal of thiophene nearly 100% can be provided in presence Fe0.5/Cu0.5, Fe0.5/Zn0.5 and Fe alone in 10, 15 and 20 minutes, respectively. Also, the effect of hydroxyl scavenger and the consumption of catalysts were studied in the proposed procedure. Techniques of gas chromatography-flame ionization detector (GC-FID), gas chromatography-sulfur chemiluminescence detector (GC-SCD) and total sulfur analyzer were used to follow thiophene degradation. A thiophene petrochemical wastewater was treated by the proposed method and the results showed significant reduction of amounts of Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD).