The degradation and mineralization of acephate by ionization irradiation

Abstract

The degradation and mineralization of acephate in aqueous solutions by 60Co‐γ irradiation were investigated. The acephate was dissolved in different pH buffer solutions and purged for 30 min using anticipate gas. It was found that the degradation ratio of acephate increased gradually with the absorbed dose, and the inorganic ions, SO42−, PO43−, and NH4+, were generated in the irradiated solutions. For the solutions without oxygen, the degradation ratio of acephate in N2‐saturated solutions containing t‐BuOH was the highest, and that in N2‐saturated solutions was higher than that in N2O‐saturated solutions. However, the total concentration of inorganic ions in N2O‐saturated solutions was higher than that in the other solutions. Moreover, the concentration of NH4+ in N2‐saturated solutions containing t‐BuOH was larger than that of SO42− and PO43−, whereas in N2‐ or N2O− saturated solutions, the concentrations of inorganic ions were in the order of SO42− > PO43− > NH4+. In the air‐saturated and O2‐saturated solutions, it was found that the concentration of inorganic ions generated was in the order of SO42− > PO43− > NH4+. The degradation degree of acephate and the concentrations of inorganic ions in O2‐saturated solutions were higher than those in the air‐saturated solutions. The result showed that both of the oxidative and reductive radicals could degrade the acephate, and the oxidative could improve the mineralization of acephate. It was further concluded that it was easier for the reductive radicals to attack the bonds around N than other bonds around S and P, and the SC and PS bond are easily attacked by oxidative radicals. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 324–332, 2015

The mechanisms and process of acephate degradation by hydroxyl radical and hydrated electron

“…Therefore, it is a concerning issue to degrade and remove acephate in the plants and environment. Many studies have done to degrade and remove acephate, most of which involve biodegradation method (Zhao et al, 2010), acid hydrolysis (Szeto et al, 1979), photocatalytic decomposition (Echavia et al, 2000), electrolyzed water treatment (Hao et al, 2011), ozone method (Wang et al, 2015), supercritical carbon dioxide method (Yu, 2002), and γ-irradiation methods (Chen et al, 2008, Yang et al, 2015, Gao et al, 2015).…”

“…The active radicals can have reacted with substances which have chemical stability and are not easy to be degrade (Sun et al, 2015, Anbar and Neta, 1967, Gao et al, 2017). Hence, 60 Co-γ irradiation methods were used to degrade acephate (Chen et al, 2008, Yang et al, 2015, Gao et al, 2015, Ong et al, 2017, Samad et al, 2017, Zaidi et al, 2017). Chen research the degradation rate of acephate by 60 Co-γ irradiation in apple juice, but the degradation pathway of acephate and the degradation compounds were not mentioned.…”

Degradation of Acephate and Its Intermediate Methamidophos: Mechanisms and Biochemical Pathways

“…The degradation of acephate mainly involves the destruction of N-C, P-N, P-S, or P-O bonds and the generation of the main intermediate products O -methl- N -acetylphosphoramidate and the more toxic methamidophos (as shown in Figure 2 ). Previous researchers have used 60 Co irradiation, which has led to many studies on the degradation efficiency, degradation pathways, and degradation dynamics ( Sun et al, 2015 ; Yang et al, 2015 ; Huang et al, 2018 ). Chemical degradation mainly results in the generation of free radicals in the medium, such as and negative hydrogen ions (•H) and hydroxyl radicals (•OH) ( Yang et al, 2015 ).…”

“…Previous researchers have used 60 Co irradiation, which has led to many studies on the degradation efficiency, degradation pathways, and degradation dynamics ( Sun et al, 2015 ; Yang et al, 2015 ; Huang et al, 2018 ). Chemical degradation mainly results in the generation of free radicals in the medium, such as and negative hydrogen ions (•H) and hydroxyl radicals (•OH) ( Yang et al, 2015 ). Reducing and oxidizing free radicals play different roles in the degradation of acephate and methamidophos, so negative hydrogen ions (•H) and hydroxyl radicals (•OH) have different reaction kinetics from acephate, which leads to two different degradation pathways of acephate ( Zhao et al, 2009 ).…”

“…photo-Fenton processes, UV/TiO 2 , ultrasonic ozonation, and ionizing irradiation, etc. are widely studied for acephate or methamidophos (Dai et al, 2008;Wang et al, 2015;Yang et al, 2015;Zheng et al, 2016). Efficient and environmentally friendly microbial degradation has been considered as the most promising remediation method (Cycoń and Piotrowska-Seget, 2016;Bhatt et al, 2019;Pang et al, 2020;Feng et al, 2020;Zhang et al, 2020).…”