6190-65-4Relevant articles and documents
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 (2017/07/07)
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.
Efficient removal of atrazine in water with a Fe3O4/MWCNTs nanocomposite as a heterogeneous Fenton-like catalyst
Yu, Lian,Yang, Xiaofang,Ye, Yushi,Wang, Dongsheng
, p. 46059 - 46066 (2015/06/08)
Fe3O4 and multi-walled carbon nanotube hybrid materials (Fe3O4/MWCNTs) were synthesized by a coprecipitation combined hydrothermal method. The nanocomposites were applied for adsorption and degradation of atrazine (ATZ) in the presence of H2O2. The obtained catalysts were characterized by TEM, XRD, BET, XPS and Raman spectroscopy. The effects of solution pH, catalysts dosage, H2O2 concentration and iron leaching on the degradation of ATZ were investigated. Fe3O4/MWCNTs showed a higher utilization efficiency of H2O2, higher ability of adsorption for ATZ and higher degradation efficiency of ATZ than Fe3O4 nanoparticles in the batch degradation experiment. The degradation efficiency increased with the solution pH decreasing from 8.0 to 3.0. The catalytic results showed that Fe3O4/MWCNTs presented good performance for the degradation of ATZ, achieving 81.4% decomposition of ATZ after 120 min at reaction conditions of H2O2 concentration 3.0 mmol L-1, catalysts dosage 0.1 g L-1, ATZ concentration 10.0 mg L-1, pH 5.0 and T 30 °C. Three degradation products (desethylatrazine, desisopropylatrazine, and 2-hydroxyatrazine) were detected during a heterogeneous Fenton reaction in solution. The stability, and reusability of Fe3O4/MWCNTs for ATZ degradation were also investigated.
Metalloporphyrins as biomimetic models for cytochrome P-450 in the oxidation of atrazine
Gotardo, Maria C. A. F.,De Moraes, Luiz A. B.,Assis, Marilda D.
, p. 10011 - 10018 (2008/02/04)
The aim of this work was to evaluate whether metalloporphyrin models could mimic the action of cytochrome P-450 in the oxidation of atrazine, a herbicide. The commercially available second-generation metalloporphyrins 5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrin metal(III) chloride [M(T-DCPP)Cl] and 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin metal(III) chloride [M(TFPP)Cl] (metal = Fe or Mn) and the oxidants iodosylbenzene and metachloroperbenzoic acid were employed in this study. Results showed that the metalloporphyrins used here can oxidize atrazine. Yields as high as 32% were obtained for the Mn(TFPP)Cl/PhIO system, which shows that these catalysts can mimic both the in vivo and the in vitro action of cytochrome P-450, with formation of the metabolites DEA and DIA. The formation of five other unknown products was also detected, but only one of them could be identified, since the other four were present in very low concentrations. The compound COA, identified by mass spectrometry, was the main product in most of the oxidation reactions.
