Phototransformation of nitrobenzene in the Songhua River: Kinetics and photoproduct analysis

Abstract

Nitrobenzene (NB) pollution of the Songhua River caused by an explosion at a petrochemical plant in Jilin City, Jilin Province, China, attracted public concern over the fate of NB in the river. As one of the efforts to predict the fate of residual NB in the river, the kinetics and mechanism of phototransformation of NB in natural water from four sections of the Songhua River were investigated. It was found that photodegradation of NB in water proceeded via pseudo-first-order reaction kinetics under simulated solar irradiation conditions, and the rate constant (k) in the ultrapure water system was 0.0168 h −1 , which was approximately half of those in the natural river water systems (0.323-0.402 h −1 ). The relatively short half-life of NB in natural river water systems (17.2-21.5 h) indicates that photodegradation might have played an important role in the loss of NB flux in the river. Nitrate concentration and alkalinity were the two main factors affecting the photochemical fate of NB, suggesting that decomposition of NB mediated by . OH was predominant in water solution with high nitrate concentrations. Three isomeric nitrophenols, o-, m-, and p-nitrophenols, as well as phenol were detected as the main organic products in natural water under natural and simulated solar irradiations.

Study of photodegradation and photooxidation of p-arsanilic acid in water solutions at pH = 7: kinetics and by-products

“…Analysis by GC/MS showed the presence of phenol, nitrophenols, dinitrophenol, and one of the isomers of azobenzene in the final solution. The results are in accordance with the results of previous researchers (Wang et al 2008;Kochany 1992;Miguel et al 2000). Fendler and Gasowski (1968) suggested that the enhanced conjugation of the nitro group with benzene ring might be responsible for the selective activation of the ortho and para positions of nitrobenzene (NB).…”

Numerical Simulation of Groundwater Flow in a River Valley Basin in Jilin Urban Area, China

“…The JUA covers 1267.89 km 2 and is located between 4840,000 and 4905,000 north and 260,000 and 320,000 east in the central of Jilin Province, China ( Figure 1). JUA has a population of 1.60 million and is an important irrigation and industrial district of China.…”

“…The area of JUA is 1267.89 km 2 and it is assumed to be a rectangular shape. The grid cells were designated as "inactive" outside the model domain and as "active" inside the model domain.…”

Nitrobenzene biodegradation ability of microbial communities in water and sediments along the Songhua River after a nitrobenzene pollution event

“…Thus, volatilization should be one of the main processes responsible for the loss of NB from river water. On the other hand, photolysis could also be responsible for the loss of NB (Wang et al, 2008).…”

“…For controlling the losses and impact of the accident at a level as low as possible, the government started a wide range of investigations to understand the behavior and fate of residual NB in the river. Evaluation of NB degradation abilities of microbes at different river sections was one of the main tasks of the investigation Wang et al, 2008).…”