**2. Setup devised for electro-peroxone (EP) and photoelectro-peroxone (PEP)**

Experimental setup has been devised for degradation of pollutants in wastewater through EP and PEP approaches, which is illustrated in **Figure 1**. Wastewater treatment was processed in air-proof semi-batch reactor [40]. One-liter wastewater was incorporated inside the reactor, and pairs of electrodes, that is, cathode and anode 1 cm apart, were interleaved in the middle of the reactor. Quartz jacket-enclosed UV lamp was perpendicularly immersed in reactor for UV photolysis during PEP process. Bubble diffuser and magnet stirrer bar were placed to diffuse mixture of ozone and O2 gases in aqueous solution and to mix content inside the reactor. Electrolytic operations such as EP and PEP were performed under galvanostatic conditions *via* direct current power supply in the presence of supporting electrolyte [36]. Additionally, constant temperature was maintained *via* water flow around reactor chamber. Ozone generator was operated to attain ozone and oxygen mixture from inlet oxygen supplied through oxygen cylinder. It was connected to ozone meter to estimate ozone concentration within reactor's inlet and outlet channels, which subsequently attached with gas flow

*Electro-Peroxone and Photoelectro-Peroxone Hybrid Approaches: An Emerging Paradigm… DOI: http://dx.doi.org/10.5772/intechopen.102921*

### **Figure 1.**

*Schematic illustration of reactor devised for electro-peroxone and photoelectro-peroxone for wastewater treatment image reproduced from ref. [18]. 1-oxygen cylinder, 2-rotameter, 3-ozone generator, 4-reactor, 5-power supply, 6-stirrer, 7-anode, 8-cathode, 9-fine bubble diffuser, 10-UV-lamp, 11-UV source.*

meter [40]. Desired quantity of ozone was incorporated inside reactor by modifying flow rate of inlet ozone gas.

### **3. Electro-peroxone approaches for diverse wastewater treatment**

In the literature, a wide spectrum of wastewater applications such as textile, pharmaceutical, biodigester effluents, refractory compounds, and real wastewater treatments have been successfully conducted by researchers as demonstrated by **Table 1**.

Textile industries are producing huge volume of wastewater nearly 30–50 cm3 water volume ton<sup>1</sup> dyes. Subsequently, dyestuff effluents (10–20 mg L<sup>1</sup> ) have been discharged into sewages and rivers [49, 50]. Treatment of textile wastewater is inappropriate through biological treatment meanwhile it culprits toxic secondary by products at the end, alternatively several oxidants have been reported which were being restricted on accountability of structural intricacy of dyestuffs. Consequently, textile wastewater treatment is prompted by EAOPs. [51–53]. Anionic dye Acid Orange 7 (C6H11N2NaO4S) containing wastewater (500 mg L<sup>1</sup> ) has been fully decontaminated with 90% and 99% exclusion of TOC and chemical oxygen demand (COD), respectively, within 90 minutes through EP approach carried out in cylindrical reactor [54]. Likewise, Acid Orange 7 was pulverized in a cylindrical baffled reactor to boost exchange among reactants and well-organized electrode arrangement by EP approach. Acid Orange 7 (500 mg L<sup>1</sup> ) mineralization cleared out 92% TOC and 99% COD were


### *Wastewater Treatment*


*Diverse EP approaches are exemplified for diverse wastewater treatment under standard reaction conditions.*

**Table 1.**
