1007-28-9Relevant articles and documents
Wet peroxide degradation of atrazine
Rodriguez, Eva M.,Alvarez, Pedro M.,Rivas, F. Javier,Beltran, Fernando J.
, p. 71 - 78 (2004)
The high temperature (150-200 °C), high pressure (3.0-6.0 MPa) degradation of atrazine in aqueous solution has been studied. Under these extreme conditions atrazine steadily hydrolyses in the absence of oxidising agents. Additionally, oxygen partial pressure has been shown not to affect atrazine degradation rates. In no case mineralisation of the parent compound was observed. The addition of the free radical generator hydrogen peroxide to the reaction media significantly enhanced the depletion rate of atrazine. Moreover, partial mineralisation of the organics was observed when hydrogen peroxide was used. Again, oxygen presence did not influence the efficiency of the promoted reaction. Consecutive injections of hydrogen peroxide throughout the reaction period brought the total carbon content conversion to a maximum of 65-70% after 40 min of treatment (suggesting the total conversion of atrazine to cyanuric acid). Toxicity of the effluent measured in a luminometer decreased from 93% up to 23% of inhibition percentage. The process has been simulated by means of a semi-empirical model.
Study of the mechanisms of the photodegradation of atrazine in the presence of two photocatalysts: TiO2 and Na4W10O32
Texier, Isabelle,Ouazzani, Jamal,Delaire, Jacques,Giannotti, Charles
, p. 3401 - 3412 (1999)
The mechanisms of the photodegradation of atrazine under direct photolysis and in the presence of two different photocatalysts, TiO2 and Na4W10O32, are investigated by the means of GC/MS, total radioactivity counting, HPLC and TLC analysis on 14C ring-labelled atrazine solutions. Integration of photo- and biodegradation processes is studied.
Integrated photocatalytic-biological treatment of triazine-containing pollutants
Chan, Cho Yin,Chan, Ho Shing,Wong, Po Keung
, p. 371 - 380 (2019)
The degradation of triazine-containing pollutants including simazine, Irgarol 1051 and Reactive Brilliant Red K-2G (K-2G) by photocatalytic treatment was investigated. The effects of titanium dioxide (TiO2) concentration, initial pH of reaction mixture, irradiation time and ultraviolet (UV) intensity on photocatalytic treatment efficiency were examined. Complete decolorization of K-2G was observed at 60 min photodegradation while only 15 min were required to completely degrade simazine and Irgarol 1051 under respective optimized conditions. High-performance liquid chromatography (HPLC), gas chromatography/mass spectrometry (GC/MS) and ion chromatography (IC) were employed to identify the photocatalytic degradation intermediates and products. Dealkylated intermediates of simazine, deisopropylatrazine and deethyldeisopropylatrazine, and Irgarol 1051 were detected by GC/MS in the initial phase of degradation. Complete mineralization could not be achieved for all triazine-containing pollutants even after prolonged (>72 h) UV irradiation due to the presence of a photocatalysis-resistant end product, cyanuric acid (CA). The toxicities of different compounds before and after photocatalytic treatment were also monitored by three bioassays. To further treat the photocatalysis-resistant end product, a CA-degrading bacterium was isolated from polluted marine sediment and further identified as Klebsiella pneumoniae by comparing the substrate utilization pattern (Biolog microplate), fatty acid composition and 16S rRNA gene sequencing. K. pneumoniae efficiently utilized CA from 1 to 2000 mg/L as a good nitrogen source and complete mineralization of CA was observed within 24 h of incubation. This study demonstrates that the biodegradability of triazine-containing pollutants was significantly improved by the photocatalytic pre-treatment, and this proposed photocatalytic-biological integrated system can effectively treat various classes of triazine-containing pollutants.
Factors affecting formation of deethyl and deisopropyl products from atrazine degradation in UV/H2O2 and UV/PDS
Luo, Congwei,Jiang, Jin,Guan, Chaoting,Ma, Jun,Pang, Suyan,Song, Yang,Yang, Yi,Zhang, Jianqiao,Wu, Daoji,Guan, Yinghong
, p. 29255 - 29262 (2017)
In this study, the formation of deethyl products (DEPs) (i.e., atrazine amide (Atra-imine) and deethylatrazine (DEA)) and deisopropyl product (i.e., deisopropylatrazine (DIA)) from parent atrazine (ATZ) degraded in UV/H2O2 and UV/PDS processes under various conditions was monitored. It was found that SO4- displayed a more distinctive preference to the ethyl function group of ATZ than HO, leading to the higher ratio of DEPs/DIA in UV/PDS system than that in UV/H2O2 system in pure water. The effects of water matrices (i.e., natural organic matter (NOM), carbonate/bicarbonate (HCO3-/CO32-), and chloride ions (Cl-)) on ATZ degradation as well as formation of DEPs and DIA were evaluated in detail. The degradation of ATZ by UV/PDS was significantly inhibited in the presence of NOM, HCO3-/CO32- or Cl-, because these components could competitively react with SO4- and/or HO to generate lower reactive secondary radicals (i.e., organic radicals, carbonate radicals (CO3-) or reactive chlorine radicals (RCs)). The yields of these DEPs and DIA products from ATZ degradation were not impacted by NOM or HCO3-/CO32-, possibly due to the low reactivity of organic radicals and CO3- toward the side groups of ATZ. Howbeit, the increase of DIA yield companied with the decrease of DEPs yield was interestingly observed in the presence of Cl-, which was attributed to the promotion of Cl- at moderate concentration (mM range) for the conversion of SO4- into HO. Comparatively, in the UV/H2O2 process, NOM and HCO3-/CO32- exhibited a similar inhibitory effect on ATZ degradation, while the influence of Cl- was negligible. Differing from UV/PDS system, all these factors did not change DEPs and DIA yields in UV/H2O2 process. Moreover, it was confirmed that RCs had a greater selectivity but a lower reactivity on attacking the ethyl function group than that of SO4-. These findings were also confirmed by monitoring the degradation of ATZ as well as the formation of DEPs and DIA in three natural waters.
The process of atrazine degradation, its mechanism, and the formation of metabolites using UV and UV/MW photolysis
Moreira, Ailton. J.,Borges, Aline C.,Gouvea, Luis F.C.,MacLeod, Tatiana C.O.,Freschi, Gian P.G.
, p. 160 - 167 (2017)
The photolytic degradationmechanism of atrazine using a UV reactor andUV/MW (electrodeless discharge lamp (Hg-EDL)) was investigated. After 120?s of UV photolysis partial degradation of atrazine had been observed and a subsequent formation of degradation products of atrazine-2-hydroxy, therefore, defining the path of atrazine degradation through UV photolysis. This system after 1200?s of exposure to UV radiation had not reached full degradation of atrazine, and its metabolite (atrazine-2-hydroxy), was the main by-product obtained for the process. When performing photolysis through the UV/Microwave combined methodcomplete atrazine degradation was obtained within a 5?s interval, besides the formation of five (5) degradation products, which are HAT, DEAT, DIAT, DEHAT and DIHAT. Therefore, defining the path of the photolytic degradation process through the UV/Microwave combined method. The total degradation of its metabolite (HAT) was observed for the period of 120?s of exposure to UV/MW radiation, and after that time there had been no signcorresponding to the respective compounds. The tests with the isolated microwave radiation were not efficient in the degradation of the atrazine and, therefore, the respective isolated energy is not applicable.The control of atrazine degradation and consequent formation of metabolites were accompanied by a high-performance liquid chromatography with a UV/Vis detector.
