Method of controlling NOx gas emission by hydrogen peroxide

摘要

Emission of NOx during acid-piclding treatment of metals in an aqueous solution containing at least nitric acid is controlled by the addition of hydrogen peroxide. The addition amount of hydrogen peroxide is minimized to avoid excessive addition by monitoring the potentiostatic electrolytic current of the solution or by combinedly monitoring the potentiostatic electrolytic current and the redox potential of the solution.