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Title: Manganese dioxide as a catalyst for oxygen-independent atrazine dealkylation

Abstract

The herbicide atrazine is widely distributed in the environment, and its reactivity with soil minerals is an important issue. The authors have studied atrazine degradation on the surface of synthetic hydrous (10% H{sub 2}O) {delta}-MnO{sub 2} (birnessite) using UV resonance Raman spectroscopy and gas chromatography. The products are mainly mono- and didealkyl atrazine. Atrazine disappearance is rapid, independent of whether O{sub 2} is present or not. MnO{sub 2} reduction is a minor reaction, and the alkyl chains are converted mainly to the alkenes, in a nonredox process. A novel dealkylation mechanism is proposed involving proton transfer to Mn(IV)-stabilized oxo and imido bonds. When O{sub 2} is present, olefin oxidation and ring mineralization are also observed as secondary reactions in addition to those discussed above. Thus {delta}-MnO{sub 2}, a common soil constituent, is found to promote efficient N-dealkylation of the herbicide atrazine at 30 C, via a nonoxidative mechanism.

Authors:
;  [1]; ;  [2];  [3]
  1. Princeton Univ., NJ (United States). Dept. of Chemistry
  2. Rutgers-the State Univ., New Brunswick, NJ (United States)
  3. Lawrence Berkeley National Lab., CA (United States). Earth Sciences Div.
Publication Date:
Sponsoring Org.:
USDOE, Washington, DC (United States); National Insts. of Health, Bethesda, MD (United States)
OSTI Identifier:
687355
DOE Contract Number:  
AC03-76SF00098; FG02-97ER14755
Resource Type:
Journal Article
Journal Name:
Environmental Science and Technology
Additional Journal Information:
Journal Volume: 33; Journal Issue: 18; Other Information: PBD: 15 Sep 1999
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; HERBICIDES; SOIL CHEMISTRY; DEALKYLATION; CATALYSTS; MANGANESE OXIDES

Citation Formats

Wang, D., Spiro, T.G., Shin, J.Y., Cheney, M.A., and Sposito, G. Manganese dioxide as a catalyst for oxygen-independent atrazine dealkylation. United States: N. p., 1999. Web. doi:10.1021/es990419t.
Wang, D., Spiro, T.G., Shin, J.Y., Cheney, M.A., & Sposito, G. Manganese dioxide as a catalyst for oxygen-independent atrazine dealkylation. United States. doi:10.1021/es990419t.
Wang, D., Spiro, T.G., Shin, J.Y., Cheney, M.A., and Sposito, G. Wed . "Manganese dioxide as a catalyst for oxygen-independent atrazine dealkylation". United States. doi:10.1021/es990419t.
@article{osti_687355,
title = {Manganese dioxide as a catalyst for oxygen-independent atrazine dealkylation},
author = {Wang, D. and Spiro, T.G. and Shin, J.Y. and Cheney, M.A. and Sposito, G.},
abstractNote = {The herbicide atrazine is widely distributed in the environment, and its reactivity with soil minerals is an important issue. The authors have studied atrazine degradation on the surface of synthetic hydrous (10% H{sub 2}O) {delta}-MnO{sub 2} (birnessite) using UV resonance Raman spectroscopy and gas chromatography. The products are mainly mono- and didealkyl atrazine. Atrazine disappearance is rapid, independent of whether O{sub 2} is present or not. MnO{sub 2} reduction is a minor reaction, and the alkyl chains are converted mainly to the alkenes, in a nonredox process. A novel dealkylation mechanism is proposed involving proton transfer to Mn(IV)-stabilized oxo and imido bonds. When O{sub 2} is present, olefin oxidation and ring mineralization are also observed as secondary reactions in addition to those discussed above. Thus {delta}-MnO{sub 2}, a common soil constituent, is found to promote efficient N-dealkylation of the herbicide atrazine at 30 C, via a nonoxidative mechanism.},
doi = {10.1021/es990419t},
journal = {Environmental Science and Technology},
number = 18,
volume = 33,
place = {United States},
year = {1999},
month = {9}
}