A Novel Zeolite Coating for Protection of Concrete Sewers from Biological Sulfuric Acid Attack |
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| Authors: | Tesfaalem Haile George Nakhla |
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| Affiliation: | 1. Department of Civil and Environmental Engineering , University of Western Ontario , London, ON, Canada , N6A 5B8;2. Department of Chemical and Biochemical Engineering , University of Western Ontario , London, ON, Canada , N6A 5B8 |
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| Abstract: | Microbial growth inhibition and resistance to biological deterioration of concrete specimens coated with silver-loaded zeolite was evaluated by measuring the time course of bacterial growth, biological sulfur oxidation, and sulfate production using Acidithiobacillus thiooxidans as a corrosive agent. Live bacterial cells declined from an initial inoculum concentration of 1.1 × 104 cell ml-1 to zero in 10 days, during which only 0.5–1% of the initial sulfur concentration of 10 g l-1 was biologically oxidized, corresponding to sulfate production rates of 35–42 mg SO 4 2 ? g ? 1 S ? 1 . Leaching coefficients of calcium and silicon in the specimens coated with silver-loaded zeolite of 1.6 × 10 ? 4 to 4.6 × 10 ? 2 cm 2 d ? 1 respectively, were only 0.8% and 1% of the uncoated specimens. |
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| Keywords: | Concrete silver loaded zeolite Acidithiobacillus thiooxidans growth inhibition Leaching |
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