Kinetics and mechanisms of radiolytic degradation of nitrobenzene in aqueous solutions.
Steady-state radiolysis experiments were performed to gain insight into the kinetics and mechanisms of nitrobenzene (NB) degradation in aqueous solutions. The degradation of NB under gamma-ray irradiation followed pseudo-first-order kinetics, and the pseudo first-order rate constant and the initial G value of NB decomposition were functionally related to both the initial NB concentration and the irradiation dose rate. Under oxidative conditions, complete mineralization of NB was achieved, whereas no total organic carbon reduction was observed under reductive conditions. The radiolytic products of NB under various conditions were identified using FTIR and GC-MS analyses. The mechanisms behind the radiolytic degradation of NB under both oxidative and reductive conditions were proposed schematically in light of the degradation products observed. In addition, calculations based on ab initio molecular orbital and density functional theory provided support for the proposed mechanisms and the preferred pathways among all the possible reactions.
Zhang
Shu-Juan
SJ
Department of Chemistry and Structure Research Laboratory, University of Science & Technology of China, Hefei, Anhui 230026, China.
Jiang
Hong
H
Li
Min-Jie
MJ
Yu
Han-Qing
HQ
Yin
Hao
H
Li
Qian-Rong
QR
D002851:Chromatography, High Pressure Liquid; D005720:Gamma Rays; D008401:Gas Chromatography-Mass Spectrometry; D007700:Kinetics; D015394:Molecular Structure; D009578:Nitrobenzenes / Q000737:chemistry*; D010084:Oxidation-Reduction / Q000528:radiation effects; D017550:Spectroscopy, Fourier Transform Infrared; D014867:Water / Q000737:chemistry*; D014877:Water Pollution, Chemical / Q000517:prevention & control*
D009578:Nitrobenzenes; D014867:Water; C036077:nitrobenzene