Effect of Fe2+ on the degradation of the pesticide profenofos by electrogenerated H2O2

Author(s)

Rocha, Robson S. ; Silva, Fernando L. ; Valim, Ricardo B. ; Barros, Willyam R. P. ; Steter, Juliana R. ; Bertazzoli, Rodnei ; Lanza, Marcos R. V.

• Document type: Journal article
• Source: JOURNAL OF ELECTROANALYTICAL CHEMISTRY; v. 783, p. 6-pg., 2016-12-15.

Abstract

The purpose of the study was to evaluate the degradation of the organophosphate pesticide profenofos in acidic medium using a gas diffusion electrode (GDE) modified with 5.0% cobalt phthalocyanine (CoPc). The degradation of profenofos was based On oxidation by H2O2 electrogenerated in situ, and experiments were performed in the absence or presence of Fe(II) catalyst. Removal of the pesticide by anodic oxidation was minimal (similar to 20%), and reached only 36% when H2O2 was electrogenerated in the absence of catalyst. However, in the presence of 0.15 mmol L-1 FeSO4 center dot 7H(2)O (electro-Fenton reaction), profenofos removal attained 91% after 60 min of process tithe while total organic carbon (TOC) was reduced by 37%. Prolonged electrolysis. under similar electro-Fenton conditions showed that 100% profenofos removal could be achieved after 2 h and a 89.9% reduction in TOC could be attained after 4 h. Analysis by gas chromatography-mass spectrometry of the by-products formed during the process revealed the progressive degradation of profenofos to o- and p-benzoquinone, with subsequent rupture of the aromatic ring to form oxalic acid and, ultimately, CO2 and H2O. It is concluded that wastewater treatments involving H2O2 electrogeneration in a CoPc-modified GDE were effective in removing profenofos and TOC from commercial formulations of profenofos. (C) 2016 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 07/08314-3 - Organophosphrous pesticides degradation (chlorpyrifos, methyl-parathion and profenofos) via electrochemical and advanced oxidation processes
• Grantee: Marcos Roberto de Vasconcelos Lanza
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/02762-5 - Development of technologies to prevent pollution: degradation and monitoring online of antibiotics in sewage
• Grantee: Robson da Silva Rocha
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 09/15357-6 - Study of Organophosphorus Pesticides Degradation using Advanced Oxidative Process by electrogenerated H2O2 in Modified Gas Diffusion Electrodes
• Grantee: Robson da Silva Rocha
• Support Opportunities: Scholarships in Brazil - Post-Doctoral