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The decisive role of acidophilic bacteria in concrete sewer networks: A new model for fast progressing microbial concrete corrosion
- Source :
- Cement and Concrete Research. 101:93-101
- Publication Year :
- 2017
- Publisher :
- Elsevier BV, 2017.
-
Abstract
- This study introduces a novel approach intertwining analytics of spatial microbial distribution with chemical, mineralogical and (micro)structural related aspects in corroded concrete sewer environments. Samples containing up to 4 cm thick corrosion layers were collected from concrete manholes and analysed using hydro-geochemical, microbiological, biochemical and mineralogical methods. Opposed to the current opinion DNA and RNA indicating microbial activity were found throughout the entire deterioration layer down to the corrosion front. Elemental distributions of corresponding areas revealed a dynamic pH- and diffusion-controlled system in which a distinct succession of elemental accumulations was unequivocally correlated with responding pH levels, associated dissolution and precipitation of solids, as well as with the spatially resolved presence of microbes. Microbial activity further coincided with massive iron deposition zones, within the inner anoxic to anaerobic corrosion layers. As a possible microbial catalyst for iron oxidation and in-situ acid production in this zone, we propose Acidithiobacillus ferrooxidans which were isolated from the deteriorated concrete. Based on the data we propose a new model in which biogenic induced in-situ acid production is a decisive factor, steering high concrete corrosion rates of > 1 cm yr − 1 .
- Subjects :
- Materials science
Precipitation (chemistry)
Spatially resolved
Metallurgy
0211 other engineering and technologies
02 engineering and technology
Building and Construction
010501 environmental sciences
01 natural sciences
Anoxic waters
Acid production
Corrosion
Acidophilic bacteria
021105 building & construction
General Materials Science
Dissolution
0105 earth and related environmental sciences
Anaerobic corrosion
Subjects
Details
- ISSN :
- 00088846
- Volume :
- 101
- Database :
- OpenAIRE
- Journal :
- Cement and Concrete Research
- Accession number :
- edsair.doi...........a4e99d0e5b07faebe3c343f6303b2218