Risk assessment of hydrogen gas production in the laboratory scale electrochemical generation of ferrate(VI)

Abstract

This paper presents a risk assessment of the formation of hydrogen gas in the electrochemical generation of ferrate(VI) under laboratory scale test conditions. The theoretical production of hydrogen gas was compared with the experimental production. The applied currents were 0.2, 0.4, 0.6 and 0.8 A on an iron steel plate with surface areas of 55.2 cm2, corresponding to the current densities of 3.62, 7.2, 10.87 and 14.49 mA cm−2, respectively. The obtained values of hydrogen, formed on the cathode, showed that both theoretical and experimental values were much less than the lower flammability limit of hydrogen in the air mixture, 4% (v/v). Results have shown that under the laboratory study conditions, the electrochemical method for ferrate generation is safe and there is no expected risk of fire, detonation or explosion as a result of hydrogen gas formation. However, to be more universally applicable, the laboratory scale experiments must be validated in a pilot plant and production scale trials.