Determination of Operating Conditions for Hydrogen Peroxide and Hydroxyl Radical Production in Electro-peroxone Process

Öz

Electro-peroxone (EPO) process is an enhanced ozonation process with a simple installation of electro-oxidation apparatus into the ozone reactor. It enables the use of excess oxygen gas caused by inefficient ozone generation by ozone generators. The sparged oxygen is reduced to form hydrogen peroxide (H₂O₂) on the cathode surface and then the electrogenerated H₂O₂ reacts with ozone to form hydroxyl radical (OH•). Thus, the highly oxidative species such as OH• and H₂O₂,are produced in the bulk solution. In this study, the effects of operating conditions such as reaction time, ozone flow rate and the applied current on the production of oxidant species were discussed. Response Surface Methodology (RSM) was used for the modeling of reaction conditions. The models employed were both significant for the production of OH• and H₂O₂. Reaction time is the most important factor in the production of oxidants. While the reaction time and ozone flow rate had a synergistic effect on OH• production, the interaction of the applied flow and the ozone flow rate affected H₂O₂ production. Optimum operating conditions were determined maximizing the OH• concentration. The short reaction time of the process may be preferred because OH• is inhibited by the electrogenerated H₂O₂ at advancing reaction times.

Anahtar Kelimeler

• Electro-peroxone,advanced oxidation,hydroxyl radical,hydrogen peroxide,response surface methodology

Kaynakça

1. 1. Hou M., Chu Y., Li X., Wang H., Yao W., Yu G., Murayama S., Wang Y. 2016. Electro-peroxone degradation of diethyl phthalate: Cathode selection, operational parameters, and degradation mechanisms. Journal of Hazardous materials; 319: 61-68.
2. 2. Munter R. 2001. Advanced oxidation processes–current status and prospects. Proceedings of the Estonian Academy of Sciences. Chemistry; 50 (2): 59-80.
3. 3. Wang H., Yuan S., Zhan J., Wang Y., Yu G., Deng S., Huang J., Wang B. 2015. Mechanisms of enhanced total organic carbon elimination from oxalic acid solutions by electro-peroxone process. Water Research; 80: 20-29.
4. 4. Wang H., Bakheet B., Yuan S., Li X., Yu G., Murayama S., Wang Y. 2015. Kinetics and energy efficiency for the degradation of 1, 4-dioxane by electro-peroxone process. Journal of Hazardous materials; 294: 90-98.
5. 5. Guo W., Wu Q.-L., Zhou X.-J., Cao H.-O., Du J.-S., Yin R.-L., Ren N.-Q. 2015. Enhanced amoxicillin treatment using the electro-peroxone process: key factors and degradation mechanism. RSC Advances; 5 (65): 52695-52702.
6. 6. Bakheet B., Yuan S., Li Z., Wang H., Zuo J., Komarneni S., Wang Y. 2013.Electro-peroxone treatment of Orange II dye wastewater. Water Research; 47 (16): 6234-6243.
7. 7. Turkay O., Barışçı S., Sillanpää M. 2017. E-peroxone Process for the Treatment of Laundry Wastewater: A Case Study. Journal of Environmental Chemical Engineering; 5(5): 4282-4290.
8. 8. Li Z., Yuan S., Qiu C., Wang Y., Pan X., Wang J., Wang C., Zuo J. 2013. Effective degradation of refractory organic pollutants in landfill leachate by electro-peroxone treatment. Electrochimica Acta; 102: 174-182.

9. 9. Li Y., Shen W., Fu S., Yang H., Yu G., Wang Y. 2015. Inhibition of bromate formation during drinking water treatment by adapting ozonation to electro-peroxone process. Chemical Engineering Journal; 264: 322-328.
10. 10. Yao W., Wang X., Yang H., Yu G., Deng S., Huang J., Wang B., Wang Y. 2016. Removal of pharmaceuticals from secondary effluents by an electro-peroxone process. Water Research; 88: 826-835.
11. 11. Li X., Wang Y., Yuan S., Li Z., Wang B., Huang J., Deng S., Yu G., 2014. Degradation of the anti-inflammatory drug ibuprofen by electro-peroxone process. Water Research; 63: 81-93.
12. 12. Li X., Wang Y., Zhao J., Wang H., Wang B., Huang J., Deng S., Yu G. 2015. Electro-peroxone treatment of the antidepressant venlafaxine: Operational parameters and mechanism. Journal of hazardous materials; 300: 298-306.
13. 13. Turkay O., Barışçı S., Öztürk B., Öztürk H., Dimoglo A. 2017. Electro-Peroxone Treatment of Phenol: Process Comparison, the Effect of Operational Parameters and Degradation Mechanism. Journal of The Electrochemical Society; 164 (9): E180-E186.
14. 14. Milan-Segovia N., Wang Y., Cannon F. S., Voigt R. C., Furness J. C 2007. Comparison of hydroxyl radical generation for various advanced oxidation combinations as applied to foundries. Ozone: Science and Engineering; 29 (6): 461-471.
15. 15. Roth J. A., Sullivan D. E. 1981. Solubility of ozone in water, Industrial & Engineering Chemistry Fundamentals; 20 (2): 137-140.
16. 16. Wang Y. The Electro-peroxone Technology as a Promising Advanced Oxidation Process for Water and Wastewater Treatment. In: In: Zhou M., Oturan M., Sirés I. (eds) Electro-Fenton Process. The Handbook of Environmental Chemistry, vol 61. Springer, Singapore, 2017.