Industrial & Engineering Chemistry Research, Vol.50, No.11, 7073-7076, 2011
Improvements in the Electrochemical Production of Ferrates with Conductive Diamond Anodes Using Goethite as Raw Material and Ultrasound
The improvement in the electrochemical production of ferrates with conductive diamond anodes using goethite as raw material and ultrasounds has been studied. The conductive-diamond electrolysis of suspensions of goethite leads to a higher ferrate concentration than that of Fe(OH)(3) suspensions and of iron-powder bed. With this raw material, the ferrate concentration increases continuously with a constant production rate, after a first more efficient stage in which results are similar to the other two raw materials. In addition, the ferrate production rate is significantly improved in the sonoelectrochemical system, suggesting that the amount of soluble iron ready to be oxidized to ferrates increases with the ultrasound effect. The initial iron concentration only seems to have an influence on the first stage of the process. On the other hand, the concentration of ferrate strongly depends on the hydroxide anion concentration: the higher is the hydroxide concentration, the higher the ferrate concentration is.