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

• Main Authors: Yuanyuan Huang, Renbang Zhao, Yencon Hung, Huiyu Gao, Penghui Zhang, Yang Wang, Mengying Sun, Dan Liu, Shuai Wang
• Format: Article
• Language: English
• Published: Elsevier 2018-02-01
• Series: Saudi Journal of Biological Sciences
• Subjects: Acephate; Electron pulse radiolysis; Reaction kinetics; Degradation pathway
• Online Access: http://www.sciencedirect.com/science/article/pii/S1319562X17302711

The degradation process of acephate in aqueous solution with ·OH and eaq− produced by 60Co-γ irradiation and electron pulse radiolysis was studied in the present paper. In the aqueous solution, acephate reacted with eaq− and transformed to transient species which can absorb weakly in the wavelength range of 300–400 nm and decay very fast. According to the decay of hydrated electron, the reaction rate constant of eaq− and acephate is (3.51 ± 0.076) × 109 dm3·mol−1·s−1. The transient species produced in the reaction of ·OH and acephate do not distinctly absorb the light in the wavelength range of 300–700 nm, so the decay and kinetics of the transient species cannot determinedirectly. The competing reaction of KSCN oracephate with ·OH were studied to obtain the reaction rate constant of ·OH and acephate, which is (9.1 ± 0.11) × 108 dm3·mol−1·s−1. Although acetylamide and inorganic ions were determined in the products of the reaction of acephate with ·OH or eaq−, the concentration of inorganic ions in the products of the reaction of acephate with ·OH is higher than that in the product of the reaction of acephate with eaq−. Moreover, there were sulfide in the products of the reaction of acephatewith eaq−. The degradation pathways of acephate by ·OH and eaq− were also proposed based on the products from GC-MS.