Removal efficiency of Enzyme Horseradish Peroxidase in Removal of Tetracycline and Ciprofloxacin from Synthetic Wastewater

Background and purpose: So far, different methods have been used to remove residual antibiotics from aquatic environments. This study investigated the efficiency of enzyme horseradish peroxidase (HRP) in presence of hydrogen peroxide in removal of Tetracycline and Ciprofloxacin in a batch system. Materials and methods: In an experimental study on laboratory scale, the effects of contact time, concentrations of H2O2, the antibiotics, and enzyme, and reaction pH on the performance of pure HRP enzyme in the presence of H2O2, were investigated. To measure the efficiency of the enzymatic process, the residual antibiotics were measured using HPLC equipped with a reverse phase column (C-18, 5% micrometer, 250 * 4.6 mm). The flow rate was 1 ml/min and the injection volume was 40 μl. The mobile phase of Tetracycline was 0.1 M TFA- methanol (60:40) used at 254 nm and the mobile phase of ciprofloxacin was 0.01 M acetonitrile- phosphate (8:92) at 220 nm. All experiments were performed in a discontinuous system at laboratory temperature. Results: Removal efficiencies of Tetracycline and Ciprofloxacin were 40% and 95%, respectively, at 10 mg/l initial concentrations of antibiotics, 10-min contact time, Tetracycline pH= 4, and Ciprofloxacin pH= 7. The removal efficiency of Ciprofloxacin was two times more than that of Tetracycline. Conclusion: The free HRP could be used as an effective process in removing Tetracycline and Ciprofloxacin from wastewater.