**3.4. Adsorption studies**

in the range of 400–4500 cm−1. The researchers noted that the observed transmittance band at

nanoparticle.

lations of bond structures that oxygen forms with iron. It is known that this nanoparticle structure oscillates between 200 and 650 cm−1. In this direction, as shown in the graph, the

XRD (X-ray diffraction) method was used for the analysis of crystallized structures of nanoparticles used in the study. In this method, since the diffraction pattern to be produced by each structure will be different, the planar structure of the elements arranged symmetrically or periodically can be determined. The graphs obtained by XRD analysis of ZnO and

Plots of 100, 002, 101, 102, 110, 103, 200, 112, 201, 004, and 202 were determined in the XRD analysis graph to show the crystallized structure of the ZnO nanoparticle. ZnO nanoparticle

nanoparticle structure obtained by green synthesis exhibited oscillations indicating spe-

nanoparticle structure shown in **Figure 3B**, there are oscil-

435 cm−1 corresponds to ZnO bonding, confirming the formation of ZnO particles.

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cific bonds between iron and oxygen elements between 256 cm and 636 cm−1.

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nanoparticle.

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In the FT-IR spectrum of the Fe<sup>3</sup>

**Figure 3.** FTIR spectrum of (A) ZnO and (B) Fe<sup>3</sup>

214 Iron Ores and Iron Oxide Materials

nanoparticles are given in **Figure 4**.

**Figure 4.** XRD spectrum for (A) ZnO and (B) Fe<sup>3</sup>

Fe<sup>3</sup> O4

Fe<sup>3</sup> O4 Analytical methods used for quantitative analysis require calibration. Calibration is a process for accurately determining the relationship between the signal measured at the output of any device and the concentration of the material causing the signal. The curve obtained is a straight line. Since the calibration curve R2 value is 0.9941, the slope is assumed to be 0.0094.

As seen in **Figure 5**, the DB15 azo dye had value of about qe = 80 mg/L with all membrane forms in the first 15 min. Measurements at 30, 45, and 60 min resulted in 80–100 mg/L qe. However, since the highest values were noted at 45 min, optimum contact time for this azo dye was accepted as 45 min. ZnO and Fe<sup>3</sup> O4 NPs have been used to study the remodeling of many azo dyes [40, 41]. The LS-ZnO membrane form provided slightly lower adsorption compared to the LS-Fe<sup>3</sup> O4 NPs membrane form. The highest adsorption was obtained with LS-ZnO/Fe<sup>3</sup> O4 NPs membrane form.


**Table 3.** Data of immobilization efficiency.

In the work for the degradation of DB15 azo dye using copper hydroxide nitrate as a catalyst by wet peroxide oxidation, it has been reported that degradation activity of 85 and 90% of this dye is obtained after 10 and 60 min at 60°C [44]. In another study, remediation of DB15 azo dye was studied with Fenton reaction, and in this study, the degradation efficiency of the system was increased in parallel with the temperature increasing from 20 to 40°C [42]. The temperatures in these studies are very high and cause extra energy consumption and therefore financial loss. In this respect, the membrane forms proposed in our work offer advantages at

The Investigation of Removing Direct Blue 15 Dye from Wastewater Using Magnetic *Luffa sponge* NPs

When **Figure 6** is examined, the adsorption of concentration of 200 mg/L DB15 azo dye solution prepared with the membrane forms had the highest value. The adsorption of the DB15 azo

adsorption of azo dye solutions prepared at other concentrations (10, 25, 50, and 100 mg/L). The use of nanoparticles has affected adsorption quite positively. Pure LS membrane form showed very low efficiency in dye adsorption compared to nanoparticle loaded membrane forms.

Adsorption values were read close to each other in the adsorption study of the DB15 azo dye solution with membrane forms formed with LS quantities of 0.025, 0.05, 0.1, 0.3, and 0.5 g. In the adsorption study of azo dye solution with nanoparticle-loaded membrane forms formed with all LS quantities used in the experiment, higher adsorption values were obtained compared to the pure LS membrane form used in the same amount. The highest percentage of recovery was obtained with 0.025 g LS (**Figure 6**). Kesraoui et al. [45] conducted biosorption of the Alpasit Blue with LS. In this study, maximum efficiency was obtained with 1 g LS fibrils after 2 h in pH 2.0 medium with 20mg/L concentration dye. In our study, the highest yield was achieved with an adsorbent amount of 0.025 g. In addition, nanoparticle loading has made this

NPs membrane forms showed the highest values were measured according to the

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http://dx.doi.org/10.5772/intechopen.73216

NPs, and

217

dye solution prepared at the concentration of 200 mg/L with LS-ZnO NPs, LS-Fe<sup>3</sup>

**Figure 6.** Effect of amount of adsorbent on adsorption with membrane forms formed by DB15 azo dye.

20°C with effective performance.

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LS-ZnO/Fe<sup>3</sup>

more efficient.

**Figure 5.** The effects of contact time, pH, temperature and dye concentration on the adsorption of the DB15 azo dye solution with the formed membrane forms.

Maximum adsorption peaks were observed at pH 8.0 in the spectrophotometric measurements performed on pH optimizations for the adsorption of DB15 azo dye solution at 50 mg/L concentration with the formed membrane forms. According to adsorption data obtained with LS-ZnO NPs and LS-Fe<sup>3</sup> O4 NPs membrane forms in pH 7.0 medium, pure LS membrane form provides a more effective adsorption in this pH environment. However, at pH 7.0, the same adsorption data were observed for LS-ZnO/Fe<sup>3</sup> O4 NPs and pure LS membrane forms (**Figure 5**).

In some studies performed onto Fenton process, a high decolorization rate was achieved for DB15 azo dye in highly acidic media such as pH 3.0 and 4.0 [42, 43]. Providing maximum yield in alkaline environment such as pH 8.0 near neutral with the formed membrane forms is advantageous in terms of operating.

The adsorption of the DB15 azo dye solution with membrane form exhibited the highest adsorption peaks at 20°C. However, when the temperature was gradually increased above 20°C, the adsorption with membrane forms showed an inverse proportion and gradually decreased. This result is quite advantageous in terms of the industrial application because the approximate temperature of 20°C is accepted as the optimum value.

In the work for the degradation of DB15 azo dye using copper hydroxide nitrate as a catalyst by wet peroxide oxidation, it has been reported that degradation activity of 85 and 90% of this dye is obtained after 10 and 60 min at 60°C [44]. In another study, remediation of DB15 azo dye was studied with Fenton reaction, and in this study, the degradation efficiency of the system was increased in parallel with the temperature increasing from 20 to 40°C [42]. The temperatures in these studies are very high and cause extra energy consumption and therefore financial loss. In this respect, the membrane forms proposed in our work offer advantages at 20°C with effective performance.

When **Figure 6** is examined, the adsorption of concentration of 200 mg/L DB15 azo dye solution prepared with the membrane forms had the highest value. The adsorption of the DB15 azo dye solution prepared at the concentration of 200 mg/L with LS-ZnO NPs, LS-Fe<sup>3</sup> O4 NPs, and LS-ZnO/Fe<sup>3</sup> O4 NPs membrane forms showed the highest values were measured according to the adsorption of azo dye solutions prepared at other concentrations (10, 25, 50, and 100 mg/L). The use of nanoparticles has affected adsorption quite positively. Pure LS membrane form showed very low efficiency in dye adsorption compared to nanoparticle loaded membrane forms.

Adsorption values were read close to each other in the adsorption study of the DB15 azo dye solution with membrane forms formed with LS quantities of 0.025, 0.05, 0.1, 0.3, and 0.5 g. In the adsorption study of azo dye solution with nanoparticle-loaded membrane forms formed with all LS quantities used in the experiment, higher adsorption values were obtained compared to the pure LS membrane form used in the same amount. The highest percentage of recovery was obtained with 0.025 g LS (**Figure 6**). Kesraoui et al. [45] conducted biosorption of the Alpasit Blue with LS. In this study, maximum efficiency was obtained with 1 g LS fibrils after 2 h in pH 2.0 medium with 20mg/L concentration dye. In our study, the highest yield was achieved with an adsorbent amount of 0.025 g. In addition, nanoparticle loading has made this more efficient.

Maximum adsorption peaks were observed at pH 8.0 in the spectrophotometric measurements performed on pH optimizations for the adsorption of DB15 azo dye solution at 50 mg/L concentration with the formed membrane forms. According to adsorption data

**Figure 5.** The effects of contact time, pH, temperature and dye concentration on the adsorption of the DB15 azo dye

membrane form provides a more effective adsorption in this pH environment. However, at

In some studies performed onto Fenton process, a high decolorization rate was achieved for DB15 azo dye in highly acidic media such as pH 3.0 and 4.0 [42, 43]. Providing maximum yield in alkaline environment such as pH 8.0 near neutral with the formed membrane forms

The adsorption of the DB15 azo dye solution with membrane form exhibited the highest adsorption peaks at 20°C. However, when the temperature was gradually increased above 20°C, the adsorption with membrane forms showed an inverse proportion and gradually decreased. This result is quite advantageous in terms of the industrial application because the

NPs membrane forms in pH 7.0 medium, pure LS

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NPs and pure LS mem-

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pH 7.0, the same adsorption data were observed for LS-ZnO/Fe<sup>3</sup>

approximate temperature of 20°C is accepted as the optimum value.

obtained with LS-ZnO NPs and LS-Fe<sup>3</sup>

solution with the formed membrane forms.

216 Iron Ores and Iron Oxide Materials

is advantageous in terms of operating.

brane forms (**Figure 5**).

**Figure 6.** Effect of amount of adsorbent on adsorption with membrane forms formed by DB15 azo dye.
