Title: Involvement of Sulfur-Oxidizing Bacteria in Concrete Deterioration

Author(s): Charles F. Kulpa and Cassandra J. Baker

Publication: Symposium Paper

Volume: 122

Issue:

Appears on pages(s): 313-322

Keywords: asbestos; bacteria; concrete pipes; deterioration; sulfur; hydrogen sulfide; reinforced concrete; thiobacillus; Materials Research

DOI: 10.14359/2534

Date: 6/1/1990

Abstract:
When anaerobic conditions occur in a sewer pipe in the presence of sulfate, sulfur-reducing bacteria will produce hydrogen sulfide. As hydrogen sulfide is released, various populations of sulfur-oxidizing bacteria (thiobacilli), will proliferate. The proliferation of these organisms results in a decrease in pH due to the production of sulfuric acid. Different thiobacilli will be present depending on the pH of the environment. Samples from regions of deteriorated and nondeteriorated concrete pipe were taken to determine the presence of microorganisms that could cause microbially induced concrete deterioration. The results presented show that the degree of concrete deterioration can be correlated with the number and type of thiobacilli present. Extensive deterioration was observed at the crown of reinforced and asbestos concrete pipe, where the most acidophilic group of thiobacilli were present in elevated numbers. Areas of lesser deterioration were somewhat acidic, with a combination of different sulfur-oxidizing thiobacilli present. Areas that did not appear to be deteriorated were populated with the least acidophilic group of sulfur-oxidizing thiobacilli. The presence of microbially induced deterioration of concrete and the stage of deterioration can be determined by utilizing selective media to culture the various groups of sulfur-oxidizing bacteria associated with concrete decay.