Treatment of Organics in Wastewater Using Electrogenerated Gaseous Oxidants

Author(s)

da Silva, Leticia Mirella ; Mena, Ismael F. ; Saez, Cristina ; Motheo, Artur J. ; Rodrigo, Manuel A.

• Document type: Journal article
• Source: Industrial & Engineering Chemistry Research; v. 63, n. 15, p. 9-pg., 2024-04-09.

Abstract

This work focuses on the comparison of the performance of direct electrochemical oxidation with indirect electrolysis mediated by gaseous oxidants in the treatment of diluted wastewater. To do this, energy consumptions of the electrolysis using mixed metal oxide (MMO) electrodes are compared with those required for the production and use of chlorine dioxide in the degradation of methomyl contained in aqueous solutions. Results demonstrate the feasibility of the mediated oxidation process and that this process is competitive with direct oxidation. The oxidants are produced under optimized conditions using the same anodic material applied for the direct degradation of organics, thus avoiding efficiency losses associated with mass transfer limitations in the degradation of dilute organic solutions. Thus, using the ClO2 gaseous oxidant, a concentration of 0.1 mM of methomyl from a solution containing 500 mL is completely removed with an energy consumption as low as 50 Wh. The application of the same energy to a direct electrolytic process for treating the same wastewater can only reach less than half of this removal. These findings may have a very important application in the use of electrochemical technology to achieve the remediation of persistent pollutants in wastewater, where their low concentrations typically make direct processes very inefficient. (AU)

• FAPESP's process: 17/10118-0 - Study and application of electrochemical technology for the analysis and degradation of endocrine interferents: materials, sensors, processes and scientific dissemination
• Grantee: Marcos Roberto de Vasconcelos Lanza
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 21/06908-0 - Electrochemical treatment for the removal of carbamates from contaminated soil
• Grantee: Leticia Mirella da Silva
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• FAPESP's process: 18/26475-9 - Evaluation and application of electrodes of oxide mixtures and boron doped diamond for the degradation of organic compounds with activity of endocrine interference
• Grantee: Leticia Mirella da Silva
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)