METHOD AND APPARATUS FOR REDUCING AN ELECTROLYTE CONTAINING NITRIC ACID

摘要

Accumulation of nitrous acid is avoided and/or production of nitrogen oxides is suppressed during an electrolytic reduction of an aqueous electrolyte containing nitric acid, and optionally organic matter to be decomposed, by adding an efficient amount of a substance reactive with nitrous acid to the catholyte in such a way that the nitrous acid formed at the cathode is entirely oxidized there to nitric acid. This method can be performed in an apparatus comprising a first container for storing and feeding an oxidable species such as an organic matter, a second container for storing and feeding a nitric acid aqueous solution and further comprising an electrolyser having an anode compartment connected to the first container and a cathode compartment connected to the second container through a nitric acid aqueous solution feeding circuit, said anode compartment and said cathode compartment being separated by a membrane, and further comprising a device for providing a mixture of water and of a substance reactive with nitrous acid and a means for injecting the said mixture into the nitric acid aqueous solution feeding circuit before said nitric acid aqueous solution enters the cathode compartment.