Experimental data on the removal of acid orange 10 dye from aqueous solutions using TiO2/Na-Y zeolite and BiVO4/Na-Y zeolite nanostructures: A comparison study

The increase of textile factories, along with the continuous development of industrialization has led to excessive discharge of high toxicity wastewater along with a diverse range of contaminants in wastewater. In this regard, to reduce their operating costs and treatment time, in this work, two synthesized nanostructures, TiO2/Na-Y zeolite and BiVO4/Na-Y zeolite was compared to remove acid orange 10 (AO10) from the aqueous solutions. The obtained optimum operating conditions including initial dye concentration, initial pH, contact time, catalyst dosage and AO10 removal efficiency were 20 mg/L, 3, 7 min, 0.2 g/100 mL, and 99.77% for TiO2/Na-Y zeolite and 20 mg/L, 3, 200 min, 0.2 g/100 mL and 46.13% for BiVO4/Na-Y zeolite composite, respectively. The structural characteristics of the synthetized materials were also determined by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and fourier-transform infrared spectroscopy (FTIR).

Nanomaterials TiO 2 /zeolite BiVO 4 /zeolite Acid orange 10 Dye degradation a b s t r a c t The increase of textile factories, along with the continuous development of industrialization has led to excessive discharge of high toxicity wastewater along with a diverse range of contaminants in wastewater. In this regard, to reduce their operating costs and treatment time, in this work, two synthesized nanostructures, TiO 2 /Na-Y zeolite and BiVO 4 /Na-Y zeolite was compared to remove acid orange 10 (AO10) from the aqueous solutions. The obtained optimum operating conditions including initial dye concentration, initial pH, contact time, catalyst dosage and AO10 removal efficiency were 20 mg/L, 3, 7 min, 0.2 g/100 mL, and 99.77% for TiO 2 /Na-Y zeolite and 20 mg/L, 3, 20 0 min, 0.2 g/10 0 mL and 46.13% for BiVO 4 /Na-Y zeolite composite, respectively. The structural characteristics of the synthetized materials were also determined by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and fourier-transform infrared spectroscopy (FTIR

Value of the Data
• TiO 2 /zeolite and BiVO 4 /zeolite composites which were synthesized by hydrothermal method, would be useful for the removal of toxic pollutants such as acid orange 10(AO10) dye from water and wastewater. • These data show the better removal efficacy of TiO 2 /zeolite composite compared to BiVO 4 /zeolite composite on acid orange 10 removal. • Process optimization using response surface methodology (RSM) by TiO 2 /zeolite and BiVO 4 /zeolite composites for dye removal yielded 99.77% and 46.13%, respectively.

Data Description
The presented data described the removal of acid orange 10 (AO10) dye by TiO 2 /zeolite and BiVO 4 /zeolite composites. The XRD pattern of TiO 2 /zeolite, TiO 2 , zeolite, BiVO 4 /zeolite, and   Fig. 1 also demonstrates the presence of Ti and Bi phase in Na-Y zeolite structure, while in the XRD pattern of Na-Y zeolite, these phases are not observed, indicating the successful coupling of TiO 2 and BiVO 4 to Na-Y zeolite structure.
These results indicate that bismuth vanadate and titanium dioxide were not destroyed during the synthesis preparation process. The FE-SEM images of nanomaterials are illustrated in Fig. 2 .
The FTIR pattern of the studied materials is also is represented in Fig. 3 Fig. 8 . Figs. 9 -12 illustrate the effects of nanomaterial dosage and pH on dye removal by the two studied nanostructures. Specification of the AO10 is presented in Table 1 . The properties of the Na-Y zeolite technical sheet are represented in Table 2 . Tables 3 and 4 illustrate studied variables and ranges for AO10 dye removal by TiO 2 /zeolite and BiVO 4 /zeolite, respectively, based on the Design-Expert 11.0.1    Table 5 . Results of analysis of variance (ANOVA) for AO10 removal efficiency model by TiO 2 /zeolite and BiVO 4 /zeolite are shown in Tables 6 and 7 , respectively. Parameter values of Langmuir and Freundlich isotherm results also are represented in Table 8 . Correlation coefficients of pseudo-first and second order kinetic models are shown in Table 9 .

Materials and methods
Acid orange 10 dye powder, titanium dioxide (APS: 20 nm and SSA: > 200 m 2 .g), Bi(NO 3 ) 3 .5H 2 O, NH 4 VO 3 , Na-Y zeolite, sodium hydroxide, and hydrochloric acid were purchased     from Sigma Aldridge and Merck companies and were used without further purification. The removal efficiency was calculated by Eq. (1) : Where C 0 and C t are the initial and final concentrations of dye at time = 0 and t , respectively.

Preparation of BiVO 4
In a simple and quick method, 0.02 mol of each of Bi(NO 3 ) 3 .5H 2 O, and NH 4 VO 3 were dissolved in 20 mL of 4 M HNO 3 , and 6 M NaOH, respectively, and stirred for 2 h at room temperature. The two solutions were mixed and stirred until a clear yellow solution was obtained. The formed slurry was then transferred to an autoclave for hydrothermal treatment and then was kept at 180 °C for 24 h. After the hydrothermal growth process, the products were washed with distilled water and ethanol and finally placed in an oven at 500 °C for 5 h [1 , 2] .

Preparation of TiO 2 /zeolite and BiVO 4 /zeolite
Here, due to the same synthesis of these two composites, both are explained together. Both composites TiO 2 /zeolite and BiVO 4 /zeolite were synthetized by the hydrothermal method, then they were mixed in equal proportions (50/50) and used in the later applications. The steps were similar to the preparation of BiVO 4 , except for the last step, which was placed in the oven at 400 °C for 2 h.

Nanomaterial experiments
The removal efficiency and photocatalytic oxidation experiments of AO10 solution were studied in a 100 mL pyrex glass vessel as a reactor by the investigated nanomaterials. A 125 W lamp (Philips) enclosed in a quartz casing for TiO 2 /zeolite immersed in the inner part of the reactor and a 12 W LED lamp (white light, light intensity = 28 mW/cm 2 , wavelength emission = 400-600 nm) for BiVO 4 /zeolite located at the top of the reaction vessel were used as light sources. The required reaction was initiated by turning on the LED and UV lamp for two systems and the samples (4 mL) were withdrawn in determined time intervals and filtered by fiberglass filter to separate nanocomposites [3] .

Experimental design
In this study, an experimental design software (Design Expert ver. 11.0.1), as well the response surface methodology (RSM) were used to determine the main factors and the interaction between them and square effects, to minimize the number of experiments and save time and cost. RSM is a method dedicated to estimating the relationship between one or more response variables and some independent variables, through a set of designed experiments and regression analysis methods. The effect of initial dye concentration, pH, contact time, and catalyst dosage factors on the dye removal process at five levels was investigated. Analysis of variance (ANOVA) was used to analyze the data. The response variable is presented in the form of a polynomial regression model in Eqs. (2) and (3) , for TiO 2 /zeolite and BiVO 4 /zeolite composites, respectively, which are presented as a function of independent variables.

Adsorption isotherms
The linear diagrams of Langmuir and Freundlich adsorption isotherms for AO10 removal on TiO 2 /zeolite and BiVO 4 /zeolite composites are presented in Figs. 5 and 6 , respectively. According to the diagrams and the values of the coefficients obtained in Table 6 , it was found that the AO10 dye adsorption on both composites TiO 2 /zeolite and BiVO 4 /zeolite follows the Langmuir model.

Investigation of adsorption kinetics
To investigate the kinetics of AO10 dye adsorption, two kinetic models including pseudo-first order and pseudo-second order kinetic models, were used. The pseudo-second order adsorption kinetics plots for TiO 2 /zeolite and BiVO 4 /zeolite are shown in Figs. 8 and 9 , respectively. The coefficients for the kinetic models can be seen in Table 9 .

Photocatalytic mechanism of studied composites
Generally, only TiO 2 and BiVO 4 can absorb photons and be stimulated to generate electron and holes pairs. In addition, the reaction between holes and OH-and H 2 O absorbed on the surface of the nanostructures particles, results in the production of OH radicals to destroy of AO10 dye. In this process, zeolite as a strong adsorbent can prevent the recombination of electron/hole pairs.

Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.