Investigation of amoxicillin removal efficiency from aqueous solutions using US/PS/CuO-Fe₃O₄ process

Antibiotics are widely used all over the world for different uses including treatment and livestock activities. Unfortunately, these emerging contaminants can enter the water sources and pollute the environment, if improperly managed. Therefore, the present study was developed to investigate the removal efficiency of amoxicillin (AMX) from aqueous solutions using the US/PS/CuO-Fe₃O₄ process. An ultrasonic bath (S60H, Elma) with a capacity of 6 L equipped with frequency of 37 kHz was used at the present study. The chemical structure and surface morphology of CuO-Fe₃O₄ nanocatalyst were characterized by BET, VSM, XRD, FE-SEM and FTIR analysis. The experimental runs were designed based on Box-Behnken design (BBD) with five input parameters. The results obtained from the present study indicated that increased CuO-Fe₃O₄ dosage and reaction time increased the AMX removal efficiency. According to the analysis of variance (ANOVA) and the predicted second-order model, pH and AMX concentration were identified as the most critical parameters in oxidation process and AMX removal efficiency. Under the optimal conditions (pH = 3.3, reaction time = 60 min, initial AMX concentration = 13 mg/L, persulfate = 0.67 g/L and CuO-Fe₃O₄ dosage = 0.7 g/L), the highest removal efficiency for AMX (98.1 %), COD (73 %) and TOC (65 %) were achieved. Based on ANOVA and the predicted second-order model, the CuO-Fe₃O₄ and reaction time were identified as the most important positive parameters in the oxidation efficiency of AMX. Overall, the results obtained from the present study indicated that US/PS/CuO-Fe₃O₄ process is a promising technology for efficient removal of AMX from the aqueous solutions.