Activation of manganese dioxide with bisulfite for enhanced abiotic degradation of typical organophosphorus pesticides: Kinetics and transformation pathway. (July 2019)

• Record Type: Journal Article
• Authors: Wang, Jianwei; Teng, Yanguo; Zhang, Caixiang; Liao, Xiaoping; Zhai, Yuanzheng; Zuo, Rui
• Is Part Of: Chemosphere. Volume 226(2019)
• Page Start: 858
• Page End: 864
• Publication Date: 2019-07
• Subjects: Organophosphorus pesticides -- Manganese dioxide -- Bisulfite -- Abiotic degradation -- Transformation pathway; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2019.03.120
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Organophosphorus pesticides (OPPs), a kind of effective insecticide, have attracted extensive attention of researchers because of the high toxicity and refractory character of their degradation products. Given the ubiquity of manganese dioxide (MnO2 ) and bisulfite (HSO3 − ) in environmental media, the abiotic degradation of several typical OPPs by the MnO2 -HSO3 - reaction system was investigated in batch experiments. As a representative OPP, methyl parathion (MP) was chosen to be the focus of the study. The removal rate of MP was remarkably improved by adding bisulfite (HSO3 − ) to the MnO2 single-reaction system, and the oxidation product methyl paraoxon was below the detection limit. The primary active substances generated from the reaction system were determined to be Mn(III) species by adding excess radical scavengers or complexants (methanol and pyrophosphate) to the reaction system. On the basis of the metabolic products of MP identified by liquid chromatography–high-resolution mass spectrometry (LC/HRMS) and gas chromatography–mass spectrometry (GC/MS), the transformation pathway of MP in the MnO2 -HSO3 - reaction system was elicited, which included the predominant processes of hydrolysis and oxidation. Furthermore, the typical OPPs with different structures were also degraded efficiently by the reaction system because of the oxidative degradation of Mn(III). This study offers significative information related to the abiotic oxidation of manganese minerals and the fate and dissipation of OPPs in the actual environment. Graphical abstract: Image 1 Highlights: HSO3 − significantly enhanced the abiotic degradation of methyl parathion by MnO2 . The primary active substance was determined to be Mn(III) in the MnO2 -HSO3 - reaction system. Transformation pathway of MP was elicited according to the identified products. Many OPPs with different structures were also degraded efficiently by the reaction system.