Electrochemical degradation of pesticide Padan 95SP by boron-doped diamond electrodes: The role of operating parameters

Abstract

Aromatic compounds can be efficiently degraded using boron-doped diamond (BDD) anodes by the anodic oxidation based on the generation of hydroxyl radicals (•OH). In this study, the degradation of Cartap in Padan 95SP (a pesticide) by BDD via the reaction between Cartap and oxidizing species (such as hydroxyl radicals, active chlorine, and persulfate) was investigated. Operating parameters including applied current density, the types of electrolyte, and the initial concentration of Padan 95SP were studied in order to determine their effect on the degradation efficiency of Cartap. The concentration of Cartap was determined by UV–Vis spectroscopy according to a 5,5-Dithiobis-(2-nitrobenzoic acid) procedure. The optimal conditions for Cartap degradation were determined (concentration of electrolyte: 0.05 M Na2SO4, initial concentration of Padan 95SP of 300 mg·L−1, pH = 3, current density: j = 20 mA·cm−2). High Performance Liquid Chromatography and Gas Chromatography/Mass Spectrometry techniques were used to characterize commercially available Padan 95SP, the decomposition of Cartap and the formation of electrochemical by-products.