The Inhibiting Effect of Sodium Ethylenediamine tetraacetate on the Autoxidation of Sodium Sulfite

摘要

In order to prevent waterside corrosion of steam generating plants used by the Navy, it is necessary to remove the dissolved oxygen from the water. In most cases this is accomplished by mechanical deaeration. When the efficiency of the deaerator is reduced, however, or when oxygen (air) leaks occur, it is necessary to supplement the oxygen-removal process with chemical treatment. Small amounts of oxygen can be scavenged economically by adding a reducing agent, such as sodium sulfite, to the feedwater. The objective of the study was to increase the effectiveness of the use of sulfite as an oxygen scavenger in closed water systems. The chelating agent chosen was disodium ethylenediamine tetraacetate (Na2EDTA). Other inhibitors were also included in some of the experiments. The autoxidation of sodium sulfite was inhibited by the EDTA. Results of experiments show that, when ions of copper and iron are chelated with EDTA, they no longer catalyze the oxidation of Na2SO3.