Enhancing the efficiency of electrochemical, Fenton, and electro-Fenton processes using SS316 and SS316/β-PbO2 anodes to remove oxytetracycline antibiotic from aquatic environments

The aim of the present study was to evaluate the efficiency of advanced oxidation processes (electrochemical, Fenton, and electro-Fenton) in the removal of oxytetracycline antibiotic from aquatic environments using SS316 and SS316/beta-PbO2 anodes. This study was performed experimentally on a laboratory scale in a 250-mL reactor. First, experiments were designed for the electrochemical process using a central composite design (CCD), and the optimal conditions for the variables pH (3.53), current density (3.85 mA/cm(2)), initial concentration of oxytetracycline (20 mg/L), and electrolysis time (42.35 min) were obtained; then, under these conditions, the efficiency of Fenton process with FeSO4 variable without the presence of electrodes was evaluated, and its optimal value was 0.3 g/L, and then in the presence of optimal values of the above four variables, the efficiency of the electro-Fenton process with H2O2 changes was investigated and the optimal value of 0.12 mg/L was obtained for H2O2. The removal efficiencies of oxytetracycline in electrochemical, Fenton, and electro-Fenton processes were 84.7%, 73.4%, and 98.2%, respectively. Under optimal conditions, the SS316/beta-PbO2 anode electrode enhanced the oxytetracycline efficiency by electro-Fenton process to 100%. The results of bioassay with microorganisms showed that the reduction of toxicity of the effluent treated by the electro-Fenton process for Pseudomonas aeruginosa and Staphylococcus aureus was 84.5% and 69%, respectively.