期刊
ENVIRONMENTAL SCIENCE & TECHNOLOGY
卷 49, 期 3, 页码 1673-1680出版社
AMER CHEMICAL SOC
DOI: 10.1021/es503496u
关键词
-
资金
- German Water Chemistry Society
Atrazine, propazine, and terbuthylazine are chlorotriazine herbicides that have been frequently used in agriculture and thus are potential drinking water contaminants. Hydroxyl radicals produced by advanced oxidation processes can degrade these persistent compounds. These herbicides are also very reactive with sulfate radicals (2.2-3.5 X10(9) M-1 s(-1)). However, the dealkylated products of chlorotriazine pesticides are less reactive toward sulfate radicals (e.g., desethyl-desisopropyl-atrazine (DEDIA; 1.5 X 10(8) M-1 s(-1)). The high reactivity of the herbicides is largely due to the ethyl or isopropyl group. For example, desisopropyl-atrazine (DIA) reacts quickly (k = 2 X 10(9) M-1 s(-1)), whereas desethyl-atrazine (DEA) reacts more slowly (k = 9.6 X 10(8)M(-1) s(-1)). The tert-butyl group does not have a strong effect on reaction rate, as shown by the similar second order reaction rates between desethyl-terbuthylazine (DET; k = 3.6 X 10(8) M-1 s(-1)) and DEDIA. Sulfate radicals degrade a significant proportion of atrazine (63%) via dealkylation, in which deethylation significantly dominates over deisopropylation (10:1). Sulfate and hydroxyl radicals react at an equally fast rate with atrazine (k (hydroxyl radical + atrazine) = 3 X 10(9) M-1 s(-1)). However, sulfate and hydroxyl radicals differ considerably in their reaction rates with humic acids (k (sulfate radical + humic acids) = 6.8 X 10(3) mgC(-1) s(-1) (mgC = mg carbon); k (hydroxyl radical + humic acids) = 1.4 X 10(4) mgC(-1) s(-1)). Thus, in the presence of humic acids, atrazine is degraded more efficiently by sulfate radicals than by hydroxyl radicals.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据