OXYGEN AND PH MICROPROFILES ABOVE CORRODING MILD-STEEL COVERED WITH ABIOFILM

Authors
Citation
Wc. Lee et D. Debeer, OXYGEN AND PH MICROPROFILES ABOVE CORRODING MILD-STEEL COVERED WITH ABIOFILM, Biofouling, 8(4), 1995, pp. 273-280
Citations number
18
Categorie Soggetti
Marine & Freshwater Biology","Biothechnology & Applied Migrobiology
Journal title
ISSN journal
08927014
Volume
8
Issue
4
Year of publication
1995
Pages
273 - 280
Database
ISI
SICI code
0892-7014(1995)8:4<273:OAPMAC>2.0.ZU;2-X
Abstract
O-2 and pH microprofiles were measured above corroding mild steel cove red with a biofilm. The pH in the anodic areas (tubercles) ranged from 5 to 7 and was always 9.45 at the surface of the cathodic areas. Afte r 1 month of biofilm development, O-2 was depleted at the anodic area but could reach the cathodic surface where it was reduced. Consequentl y, differential O-2 concentration cells were the driving force for cor rosion. The O-2 microprofiles indicated that O-2 was consumed in the t ubercles, probably by microbial activity, while O-2 was reduced electr ochemically in the cathodic areas. It was concluded that O-2 transfer to the cathodic surface was the rate limiting step for the corrosion p rocess.