Reduction of Metal Ion Species in Contaminated Water by Utilizing Potassium Ferrate (K2FeO4) Treatment

Abstract

Aims: To demonstrate that potassium ferrate will remove potentially toxic metal ions from contaminated water samples. Study Design: A known amount of metal ions were solubilized in aqueous solution, then exposed to potassium ferrate in known amounts. Extent of removal was monitored by ion chromatography and visible spectroscopy. Place and Duration of Study: Department of Chemistry, Durham Science Center, 6001 Dodge Street, Omaha Nebraska 68182 USA. Methodology: Known amounts of iron (II), manganese (II), copper (II), and calcium were solubilized in aqueous solution to known molarity. These mixtures were treated by utilizing potassium ferrate in known amounts. The presence of metal ions was monitored by ion chromatography and/or visible spectroscopy before and after treatment with potassium ferrate. Potassium ferrate was present with metallic ions for 24 hours at 21ºC. Results: Metal ions were placed in aqueous solution, iron (II) as Fe(NH4)2(SO4)2, copper (II) as CuCl2•2H2O, manganese (II) as MnCl2•4H2O, and magnesium (II) as magnesium chloride, calcium as calcium chloride. Potassium ferrate treatment did not remove chloride (Cl-), ammonium (NH4+), and sulfate (SO42-). The cation calcium was decreased by 84.0%, magnesium was decreased by 42.5%, copper (II) was removed by 100%, iron (II) by 48.7%. Reduction of calcium, magnesium, copper, and iron (II) was monitored by ion chromatography.  Reduction of iron (II), manganese, and copper (II) was monitored by visible spectroscopy. Substantial reduction of metallic ions was found in all tests after a 24 hour period at 21ºC. Conclusion: These metals have been associated with oxidative stress, damage to mental and central nervous system function. Potassium ferrate is shown to be efficient in removing many of these potentially harmful ions. Visible spectroscopy and ion chromatography is shown to be effective in monitoring the reduction of metallic ions during investigations or potassium ferrate treatment of contaminated water.