Electrochemical Synthesis of Ferrate (FeO42–) in Extreme Alkaline Medium and its Application in Dye Degradation

Abstract

Synthesis of ferrate (FeO42−) from iron plate of transformer waste electrochemically in high alkaline medium and its application for dye degradation has been carried out. The effect of parameters such as time, NaOH concentration, type of electrolyte solution and ferrate stability were studied. The ferrate solution formed is dark purple in colour with a maximum wavelength of 505 nm. The ferrate was compacted by fresh drying to produce Na2FeO4 crystals and characterized by XRF, XRD and FT-IR techniques. The ferrate was applied to degrade methylene blue, methyl orange, rhodamine and remazol black B dyes. The results showed the highest degradation of dyestuff in methylene blue by 98% and COD reduction by 73.69% at pH 8, ferrate dose of 1.1 mg and contact time of 70 min. This shows that ferrate is an environmentally friendly material which can be used to degrade toxic dyes.