Perchlorate Removal Using a Minimized Dosage of Electrodeposited Zero-Valent Iron

Abstract

AbstractThis study attempted to develop an effective alternative to remove perchlorate (ClO4−) in water by using electrodeposited zero-valent iron (Fe0) as an electron donor. Zero-valent iron was prepared on a titanium sheet as substrate through cathodic electrodeposition of ferrous ions in the presence of organic matter. It was observed that the freshly prepared Fe0 was nearly free of oxides, whereas after reductive removal of ClO4−, a mixture of iron oxides (γ-Fe2O3/Fe3O4) in a crystalline hexagonal plate shape was formed. The reaction rates of ClO4− removal relied on the dosages of Fe0. At pH 6.5, 80.9% of 1 mM ClO4− was removed in 336 h using 10 mM Fe0. This value of electrodeposited Fe0 dosage for sustaining the effective removal of ClO4− was at least 90x smaller than the Fe0 dosages previously reported. The accumulation of chloride ion, which was the only detected product containing chlorine, was detrimental to further reaction. The reduction reaction was faster at neutral pH than at acidic or basic...