Fe(II)/과황산/전기화학적 산화 공정에 의한 2,4-D의 제거

초록

The removal of 2,4-dichlorophenoxyacetic acid (2,4-D) in aqueous solution by coupled electro-oxidation and Fe(II) activatedpersulfate oxidation process was investigated. The electrochemical oxidation was performed using carbon sheet electrode andpersulfate using Fe(II) ion as an activator. The oxidation efficiency was investigated by varying current density (2 - 10 mA/cm2), electrolyte (Na2SO4) concentration (10 - 100 mM), persulfate concentration (5 - 20 mM), and Fe(II) concentration (10 -20 mM). The 2,4-D removal efficiency was in the order of Fe(II) activated persulfate-assisted electrochemical oxidation(Fe(II)/PS/ECO, 91%) > persulfate-electrochemical oxidation (PS/ECO, 51%) > electro-oxidation (EO, 36%). The persulfatecan be activated by electron transfer in PS/ECO system, however, the addition of Fe(II) as an activator enhanced 2,4-Ddegradation in the Fe(II)/PS/ECO system. The 2,4-D removal efficiency was not affected by the initial pHs (3 - 9). Thepresence of anions (Cl and HCO3) inhibited the 2,4-D removal in Fe(II)/PS/ECO system due to scavenging of sulfateradical. Scavenger experiment using tert-butyl alcohol (TBA) and methanol (MeOH) confirmed that although both sulfate(SO4•−) and hydroxyl (•OH) radicals existed in Fe(II)/PS/ECO system, hydroxyl radical (SO4•−) was the predominant radical.

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