Effects of Pollutants and Microorganisms on the Absorption of Electrolytic Hydrogen in Iron.
Abstract
The objective of this research are to (1) define the conditions under which pollutants, in particular those produced by bacteria such as sulfide end product of the SRB, affect the amount of hydrogen absorbed by iron/steel during open circuit corrosion and under cathodic polarization conditions and (2) develop effective inhibitors for reducing hydrogen absorption. Thiosulfate in acidic solutions increases the hydrogen absorption into iron order of magnitude at 10mM while having little effect on the hydrogen evolution reaction (HER) kinetics. Sulfite ions behave the same as thiosulfate. Such sulfite forms sulfurous acid in acidic solutions. The main effect of the thiosulfate is due to its decompositions product, sulfurous acid, with a small contribution from colloidal sulfur, its other decomposition product. The role of thiosulfate in neutral chloride solutions is underway. BTA decreases the hydrogen surface coverage, the discharge rate constant of the HER and the absorption/desorption equilibrium constant of the HAR. The results also show that BTA increases the recombination rate of the HER. These effects together are responsible for the decreased rates of both the HER and the HAR in presence of BTA.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1998
- Accession Number
- ADA347608
Entities
People
- Howard W. Pickering
Organizations
- Pennsylvania State University