Tetracycline removal using NaIO₄ activated by MnSO₄: Design and optimization via response surface methodology

The appearance of recalcitrant organic pollutants such as antibiotics in water bodies has gained a lot of attention owing to their adverse effects on organisms and humans. The current study aims to develop a novel approach to eliminate antibiotic tetracycline (TC) from a synthetic aqueous solution based on the advanced oxidation process triggered by MnSO₄-catalyzed NaIO₄. A single-factor experiment was performed to observe the impact of pH, NaIO₄ concentration, and MnSO₄ dosage on TC decomposition, and a three-factor, three-level response surface experiment with TC removal rate as the dependent variable was designed based on the range of factors determined from the single-factor experiment. The single-factor experiment revealed that the ranges of pH, NaIO₄ concentration, and MnSO₄ dosage need to be further optimized. ANOVA (analysis of variance) results showed that the data from the response surface experiment were consistent with the quadratic model with high R² (0.9909), and the predicted values were very close to the actual values. After optimization by response surface methodology, the optimal condition obtained was pH = 6.7, [NaIO₄] = 0.39 mM, and [MnSO₄] = 0.12 mM, corresponding to a TC removal of 96.56%. This optimization condition was fully considered to save the dosage of the high-priced chemical NaIO₄.