Photocatalytic degradation of tetracycline aqueous solutions by nanospherical α-Fe2O3 supported on 12-tungstosilicic acid as catalyst: using full factorial experimental design

Abstract

In this paper, spherical a-Fe 2 O 3 nanoparticles (NPs) were supported on the surface of 12-tungstosilicic acid (12-TSAÁ7H 2 O) using two different solid-state dispersion (SSD) and forced hydrolysis and reflux condensation (FHRC) methods. Photocatalytic activity of supported a-Fe 2 O 3 NPs (a-Fe 2 O 3 /12-TSAÁ7H 2 O) for tetracycline (TC) degradation in aqueous solution was investigated using UV/H 2 O 2 process and the results were compared with that of pure a-Fe 2 O 3 NPs. a-Fe 2 O 3 and 12-TSAÁ7H 2 O were synthesized according to previous reports and all products were characterized by using FTIR, SEM, EDX and XRD. Design of experiments (DoEs) was utilized and photocatalytic degradation process was optimized using full factorial design. The experiments were designed considering four variables including pH, the initial concentration of TC, catalyst concentration and H 2 O 2 concentration at three levels. TC concentration reduction in the medium was measured using UV/Vis spectroscopy at k max = 357 nm. The results of experiments indicated that supporting a-Fe 2 O 3 NPs on the surface of 12-TSAÁ7H 2 O through SSD and FHRC methods caused to improve the filtration, recovery and photocatalytic activity of NPs. Also, it was indicated that those NPs supported through SSD method, have better photocatalytic performance than those supported through FHRC method. The statistical analyses revealed that the maximum TC degradation (97.39%) is obtained under those conditions in which pH and catalyst concentration variables are at maximum levels and the initial concentration of TC and H 2 O 2 concentration variables are at minimum levels (pH 8, catalyst concentration = 150 ppm, initial concentration of TC = 30 ppm, H 2 O 2 concentration = 0.1 ppm). A first order reaction with k = 0.0098 min-1 was observed for the photocatalytic degradation reaction.

Effects of 462 nm Light-Emitting Diode on the Inactivation of Escherichia coli and a Multidrug-Resistant by Tetracycline Photoreaction

“…Compared to the green and red light, blue light excitation provided the highest efficacy of TC degradation. To decompose TC from water, a heavy metal-based catalyst, such as TiO 2 [ 35 , 36 ], SrTiO 3 [ 37 ], ZnO [ 38 ], Fe 2 O 3 [ 39 ], and Fe 2+ or Fe 3+ /H 2 O 2 [ 40 ], are usually added and activated with UV radiation. However, heavy metals and UV radiation are hazardous to the environment and animals.…”

Catalytic oxidation of SO2 by novel Mn/copper slag nanocatalyst and optimization by Box-Behnken design

“…The analysis of variance provides a statistical process that determines the means of several groups are equal or not. F value is used to test the significance of the model, individual variables and their interactions [29,30]. The p value is used to check the significance of the coefficient and p value < 0.05 shows that the model is significant and higher than 5% model is not significant.…”

Photocatalytic Degradation of Azo Dye Acid Red 14 from Aqueous Solutions Using MWCNTs Nanocatalyst

“…In this study, for degradation of dye as dangerous pollutants used a photoreactor with capacity 0.5 L that shows the schematic diagram in Fig.1. The photodegradation process using full factorial experimental design was studied by many investigators (18)(19)(20). The maximum photodegradation efficiency of AR14 obtained in this study was found to be 90.65%, corresponding to the operating conditions of 3, 30 mg L -1 and 20 ppm respectively, for the pH, catalyst amount and H 2 O 2 concentration.…”