Catalytic Oxidation of Imidacloprid Insecticide by Cu(II)/Peroxymonosulfate System

Author(s)

Nunez-de la Rosa, Yeison ; Ballesteros-Ballesteros, Vladimir A. ; Durango, Luis Guillermo Cuadrado ; Toledo, Jorge Luis Nisperuza ; Fernandes, Maria Fatima das Gracas ; Aquino, Jose M.

• Document type: Journal article
• Source: WATER AIR AND SOIL POLLUTION; v. 236, n. 5, p. 13-pg., 2025-05-01.

Abstract

Water contamination by synthetic organic compounds is one of the major environmental issues facing the world today. Among the available methods to treat them, catalytic advanced oxidation processes using Cu(II) ions to activate peroxymonosulfate is a potential candidate at slightly alkaline conditions (pH 8). In this work, we investigated the influence of PMS concentration (0-1000 mu mol L-1), solution pH (7-10), and the effect of water matrix (ultrapure, tap, and simulated municipal wastewater-SMWW) on imidacloprid (IMD) insecticide oxidation. After optimization of the investigated variables (500 mu mol L-1 PMS and pH 8), almost complete IMD oxidation was achieved in 6 h using ultrapure and tap water. The main detected byproducts resulting from IMD oxidation in ultrapure water are due to hydroxylation reactions and rupture of the imidazolidine ring. When SMWW was used, IMD oxidation was only 10% in 6 h, probably due to the scavenging effect of inorganic and organic compounds. The main produced working oxidants were radical (mainly HO center dot and SO4 center dot-) and non-radical (1O2, Cu(I), and Cu(III)) species, based on scavenging experiments and mass spectrometry detection of produced DMPO byproducts. Among these, HO center dot species seems to promptly oxidize IMD. (AU)

• FAPESP's process: 14/50918-7 - INCT 2014: for the Biorational Control of Pest-Insect and Phytopathogens
• Grantee: Maria Fátima das Graças Fernandes da Silva
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 19/07943-4 - Comparative study of homogeneous and heterogeneous systems with nano/micrometric particles for the degradation of organic pollutants through in situ homolysis of oxidants
• Grantee: José Mario de Aquino
• Support Opportunities: Regular Research Grants
• FAPESP's process: 21/13604-8 - Unraveling the mechanism of action of magnetic ferrites: contribution of homogeneous and heterogeneous processes for the degradation of organic pollutants via in situ activation of oxidants
• Grantee: José Mario de Aquino
• Support Opportunities: Regular Research Grants