Mineralization of CCl4 by the UVC-photolysis of hydrogen peroxide in the presence of methanol

被引：46

作者：

Gonzalez, Monica C.

Le Roux, Galo Carrillo

Rosso, Janina A.

Braun, Andre M.

机构：

[1] INIFTA, RA-1900 La Plata, Argentina

[2] Univ Sao Paulo, Escola Politecn, Dept Engn Quim, BR-05508900 Sao Paulo, Brazil

[3] Univ Karlsruhe, Lehrstuhl Umweltmesstech, D-76128 Karlsruhe, Germany

来源：

CHEMOSPHERE | 2007年 / 69卷 / 08期

关键词：

hydroxyl radicals; trichloromethyl radicals; hydroxymethyl radicals; carbon dioxide radical anion; reductive bond splitting;

D O I：

10.1016/j.chemosphere.2007.05.076

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

A method for a photochemically induced mineralization Of CCl4 is described in which use is made of reductive radicals. The UVC-photolysis (254 nm) of H2O2 added to aqueous solutions Of CCl4 is leading to the homolysis of the oxidant yielding hydroxyl radicals (HO-) that subsequently react with added methanol to generate hydroxymethyl radicals (.CH2OH). The latter radicals initiate mineralization Of CCl4 by reductive C-Cl bond splitting. CHCl3, C2Cl4 and C2Cl6 were found as reaction intermediates, but are quantitatively depleted in a parallel oxidative reaction manifold leading to mineralization. Carbon dioxide radical anion, CO2-, an intermediate in the mineralization pathway of methanol, is also shown to initiate the mineralization Of CCl4 by reductive dechlorination. A reaction mechanism is proposed and validated with computer simulations of all the experimental results. (C) 2007 Elsevier Ltd. All rights reserved.

引用

页码：1238 / 1244

页数：7

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