과황산을 이용한 2,4-D의 산화: 하이드록실아민, 킬레이트제의 영향

초록

The chemical warfare agents (CWAs) have been developed for offensive or defensive purposes and used as chemicalweapons in war and terrorism. The CWAs are exposed to the natural environment, transported through the water systemand then eventually contaminate soil and groundwater. Therefore, effective decontamination technology to remediateCWAs are needed. The CWAs are extremely dangerous and prodution is strictly prohibited, therefore, it is difficult to useCWAs even in experimental purpose. In this study, 2,4-dichlorophenoxyacetic acid (2,4-D) was chosen as a modelrepresentative CWA because it is a simulant of anti-plant CWAs and one of the major component of agent orange. Theoptimum degradation conditions such as oxidant:activator ratio were determined. The effects of hydroxylamine andchelating agents such as citric acid (CA), oxalic acid (OA), malic acid (MA), and EDTA addition to increase Fe2+activation were also investigated. Scavenger experiments using tert-butyl alcohol (TBA) and ethanol confirmed thatalthough both sulfate (SO4•−) and hydroxyl radical (•OH) existed in Fe2+-persulfate system, sulfate radical was thepredominant radical. To promote the Fe2+ activator effect, the effect of hydroxylamine as a reducing agent wasinvestigated. In chelating agents assisted Fe2+-persulfate oxidation, the addition of 2 mM of CA and MA enhanced 2,4-Ddegradation. In contrast, EDTA and OA inhibited the 2,4-D removal due to steric hindrance effect.

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