**2.5 Sludge characterization**

EC method is said to generate less sludge compared to chemical coagulation, eventhen it is important to take appropriate measures for the reuse or safe disposal

**195**

of zinc.

*Treatment of Textile Dyeing Waste Water Using TiO2/Zn Electrode by Spray Pyrolysis…*

of sludge in order to determine the quantification and characterization of the sludge generated and characterization of the sludge plays a major role in deciding healthy discarding or reclamation. Therefore by filtration technique, the sludge formed during the process was separated and placed in the drying oven for about 24 hours

The adhesion strength between the coating and the substrate was tested by applying the Scotch tape test on the deposited films before any characterization. In general, if the film adheres to the substrate and it does not peel off the substrate, adhesion strength is considered to be good and it was found good for TiO2/Zn.

The morphological, and structural analysis of TiO2/Zn electrodes were carried

Non-destructive tool X-ray diffraction (XRD) is used for the identification and determination of structural properties such as train, grain size, expitaxy, phase composition, and crystalline phases and orientation of the deposited film. The research was conducted to study the micro structure of the particles present in the electrode and sludge using the JEOL-JDX 8030 Model 6000 diffractometer with

Surface morphology studies were performed by JEOL, JSM 35 CF, Japan, using a Scanning Electron Microscope (SEM). Energy Dispersive X-Ray Spectroscopy Energy Dispersive X-Ray Spectroscopy (EDS) was used for the elemental analysis.

The surface morphology, composition of elements present and the microscopic

Zinc substrate and TiO2 coated zinc by spray pyrolysis were studied for their surface morphology and elemental analysis using Scanning Electron Microscope (SEM) and Energy Dispersive X-Ray Spectroscopy. The SEM micro-graph and EDS

The TiO2 SEM micrograph showed dense particles and their shape was in regular pattern. Obviously, the Ti and O peaks can be seen in both EDS spectra with peaks with chlorine on the coated surface. Morphology of SEM monographs show that the surface are porous. Furthermore the cracks in the surface layer are evident beyond the pores, which may imply too fast volume growth of the TiO2 layer on the zinc substrate. The elemental constituents of TiO2 nanoparticles were analysed using EDS, **Figure 4** shows the EDS spectra for TiO2 particles on the zinc substrate, peaks around 0.2, 0.3 and 4.3 keV are attributed to the binding energies of titanium and oxygen of TiO2. This finding confirms the existence of elemental compounds with an impurity peak corresponding to chlorine from the precursor TiCl3 on the zinc substrate. The peaks of 0.25, 8.5, 9.8 keV are linked to the oxygen-binding energies

structure in the electrode were analyzed using SEM, EDS and XRD.

spectrum of zinc and TiO2/Zn are given in **Figure 4**.

out by X-Ray diffractometer and Scanning Electron Microscope (SEM).

*DOI: http://dx.doi.org/10.5772/intechopen.95325*

**3. Characterization techniques**

Cu-K a radiation (λ = 0,15406 nm).

**4. Results and discussion**

**4.1 Characterization of TiO2/Zn**

**3.1 Adhesion test**

at 100°C and dried, which was then weighed [27].

**3.2 Microstructural and phase characterization**

**Figure 3.** *Photograph of the (a) dye solution, (b) after EC sludge settling, (c) sludge floating.*

*Treatment of Textile Dyeing Waste Water Using TiO2/Zn Electrode by Spray Pyrolysis… DOI: http://dx.doi.org/10.5772/intechopen.95325*

of sludge in order to determine the quantification and characterization of the sludge generated and characterization of the sludge plays a major role in deciding healthy discarding or reclamation. Therefore by filtration technique, the sludge formed during the process was separated and placed in the drying oven for about 24 hours at 100°C and dried, which was then weighed [27].

## **3. Characterization techniques**

#### **3.1 Adhesion test**

*Dyes and Pigments - Novel Applications and Waste Treatment*

separated as sludge settling and floating are given in **Figure 3**.

The ultraviolet–visible spectrophotometer (Jasco V-670 spectrophotometer) was used to measure the wavelength (542 nm) of dye. The calculation of color removal efficiencies (CRE %) after electrocoagulation treatment was performed using the formula,

Where Ai and Af were the absorbance of the dye in solution afore electrocoagulation and at the time *t*, respectively. Using a conductivity metre (Elico CM180) and a pH metre (Eutech), the electrical conductivity and pH of different dye concentra-

EC method is said to generate less sludge compared to chemical coagulation, eventhen it is important to take appropriate measures for the reuse or safe disposal

*Photograph of the (a) dye solution, (b) after EC sludge settling, (c) sludge floating.*

Colour removal efficiency CRE% A A / A ( ) = ∗− 100 ( if i ) (1)

effective electrode area was 28.16 cm2

**2.4 Colour removal efficiency**

as it is given in Eq. (1).

tions were measured.

**2.5 Sludge characterization**

The electrodes were used with dimensions of 9 cm × 3.2 cm × .5 cm. The total

The electrodes were connected to a digital dc power supply (var tech) providing a current ranging from 0.05 to 0.3A. 500 ml electro coagulation cell that contained the 250 ml test solution and a magnetic stirrer was used to stir the solution, thereby enhancing the efficiency. The applied current was adjusted to a desired value and the coagulation was started. In each run, 250 ml of dye solution was placed into the electrolytic cell. Before each run, electrodes were washed with water and dipped in 15% hydrochloric acid in order to remove dust from the electrode plates and thus weigh the electrodes after drying. The electrode plates are washed with water at the end of each run, dried and weighed at last. Whattman filter paper was used to filter the subsequent treated sample and filtrate was used for the analysis. The individual effects of electrolysis time and applied current on colour removal efficiency were quantified in this analysis (CRE). The pH was adjusted by adding 0.5 M HCl or 0.5 M NaOH. The conductivity of solutions was raised and adjusted to different values by the addition of NaCl. All experiments were carried out at constant temperature of 25°C. Two sets of EC process were carried out with 'A' and 'B' electrodes with operating parameters like pH, EC time, dye concentration, addition of electrolyte NaCl and applied current for optimization to achieve higher Color Removal Efficiency (CRE%). On the basis of the initial experiments, other parameter rates were considered constant. The experimental set up in EC process, after the experiment, the coagulated dye solution getting

and the spacing between electrodes was 1 cm.

**194**

**Figure 3.**

The adhesion strength between the coating and the substrate was tested by applying the Scotch tape test on the deposited films before any characterization. In general, if the film adheres to the substrate and it does not peel off the substrate, adhesion strength is considered to be good and it was found good for TiO2/Zn.

#### **3.2 Microstructural and phase characterization**

The morphological, and structural analysis of TiO2/Zn electrodes were carried out by X-Ray diffractometer and Scanning Electron Microscope (SEM).

Non-destructive tool X-ray diffraction (XRD) is used for the identification and determination of structural properties such as train, grain size, expitaxy, phase composition, and crystalline phases and orientation of the deposited film. The research was conducted to study the micro structure of the particles present in the electrode and sludge using the JEOL-JDX 8030 Model 6000 diffractometer with Cu-K a radiation (λ = 0,15406 nm).

Surface morphology studies were performed by JEOL, JSM 35 CF, Japan, using a Scanning Electron Microscope (SEM). Energy Dispersive X-Ray Spectroscopy Energy Dispersive X-Ray Spectroscopy (EDS) was used for the elemental analysis.

#### **4. Results and discussion**

### **4.1 Characterization of TiO2/Zn**

The surface morphology, composition of elements present and the microscopic structure in the electrode were analyzed using SEM, EDS and XRD.

Zinc substrate and TiO2 coated zinc by spray pyrolysis were studied for their surface morphology and elemental analysis using Scanning Electron Microscope (SEM) and Energy Dispersive X-Ray Spectroscopy. The SEM micro-graph and EDS spectrum of zinc and TiO2/Zn are given in **Figure 4**.

The TiO2 SEM micrograph showed dense particles and their shape was in regular pattern. Obviously, the Ti and O peaks can be seen in both EDS spectra with peaks with chlorine on the coated surface. Morphology of SEM monographs show that the surface are porous. Furthermore the cracks in the surface layer are evident beyond the pores, which may imply too fast volume growth of the TiO2 layer on the zinc substrate.

The elemental constituents of TiO2 nanoparticles were analysed using EDS, **Figure 4** shows the EDS spectra for TiO2 particles on the zinc substrate, peaks around 0.2, 0.3 and 4.3 keV are attributed to the binding energies of titanium and oxygen of TiO2. This finding confirms the existence of elemental compounds with an impurity peak corresponding to chlorine from the precursor TiCl3 on the zinc substrate. The peaks of 0.25, 8.5, 9.8 keV are linked to the oxygen-binding energies of zinc.

**Figure 4.** *(a, b) SEM, EDS image of Zinc, (c, d) TiO2/Zn.*

The X-ray diffractograms of TiO2/Zn and zinc are shown in **Figure 5**. The diffraction peaks of TiO2 phase, and the substrate zinc are present in the investigated electrode.

The particle size of TiO2 is related to the diffraction peak broadening, so X-ray diffraction spectra of coated TiO2 nanoparticles were taken and particle size and phase composition were determined. The lattice parameter observed a = b = 3.780, c = 9.513. The average particle size calculated by using Scherer Eq. indicated high surface area [28].

The particle size of nanomaterial is related to the diffraction peak broadening, so X-ray diffraction spectra of synthesized TiO2 nanoparticles were taken and peak size and composition were determined. Sharp peaks obtained corresponding to the planes (104), (018), (110), (024), (024) and (300) confirmed the nanocrystalline anatase structure. It shows the primitive hexagonal structure of nanoparticles of TiO2. TiO2 deposition is consistent with 2 theta values (30,32,35,47,56,63,68) and Zn deposition with 2 theta values (36,43,54,70,78) from the XRD results. The data was compared with JCPDS card no:71-1059 for TiO2 and 65-3358 for Zn. In the XRD pattern, no other impurity peak was observed.
