Levofloxacin removal from wastewater by photocatalytic process with nano-porous SnO2 structure: Experimental analysis by response surface methodology

In this study an annealed nanopore-structure Tin film was prepared by water to evaluate its photocatalytic performance for removal aqueous solution of levofloxacin (LEVO). In order to minimize costly and time-consuming of experiments, Design Expert software (version 11) according to the Box-Behnken design (BBD) method was employed. Accordingly, 27 experiments were designed to specify the optimal operational conditions of temperature (20 to 40 °C), initial concentration of LEVO (30 to 150 mg/L), pH (5 to 9), and resistance time (10 to 30 min) to achieve the maximum removal efficiency (%RE). The ANOVA table exposed that not only the transformed cubic model with the best lambda of 1.63 is significant, but also the Lack of Fit is not significant. Since the distance between the predicted R 2 (0.8468) and the adjusted R 2 (0.9921) is <0.2, the model was applied for determining operational conditions at the maximum %RE. Consequently, input LEVO concentration of 36.68 mg/L, contact time of 28.38 min, pH value of 5.16, and 36.87 ° C lead to the maximum %RE of 87.31 which is in good agreement with experimental %RE of 85.9. • Nanopore-structure of SnO 2 was prepared to removal of levofloxacin (LEVO). • 27 experiments were designed according to Box-Behnken design (BBD) method. • Temperature, initial concentration, pH, and resistance time were examined. • The ANOVA exposed that the cubic model with the lambda of 1.63 is significant. • C in = 37mg/L, τ = 28 min, pH = 5.2, and T = 37 ° C lead to the RE of 87%.