Inhibition of microbial concrete corrosion by Acidithiobacillus thiooxidans with functionalised zeolite-A coating.
The inhibition of the corrosive action of Acidithiobacillus thiooxidans on concrete specimens coated by functionalised zeolite-A containing 14% zinc and 5% silver by weight was studied. Uncoated concrete specimens, epoxy-coated concrete specimens (EP), and functionalised zeolite-A coated concrete specimens with epoxy to zeolite weight ratios of 3:1 (Z1), 2:2 (Z2) and 1:3 (Z3) were studied. Specimens were characterised by x-ray powder diffraction and field emission scanning electron microscopy for the identification of corrosion products and morphological changes. Biomass growth at the conclusion of the 32-day experiments was 4, 179 and 193 mg volatile suspended solids g(-1) sulphur for the uncoated, EP and Z1 specimens, whereas that of Z2 and Z3 were negligible. In the uncoated, EP and Z1 specimens, sulphate production rates were 0.83, 9.1 and 8.8 mM SO(4)(2-) day(-1) and the specific growth rates, mu, were 0.14, 0.57 and 0.47 day(-1), respectively. The corresponding values for Z2 and Z3 were negligible due to their bacterial inhibition characteristics.
Department of Civil and Environmental Engineering, University of Western Ontario, London, ON, Canada.
Tesfaalem
T
Haile
George
G
Nakhla
D013856:Acidithiobacillus thiooxidans / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism; D003252:Construction Materials / Q000382:microbiology*; D003343:Corrosion; D008855:Microscopy, Electron, Scanning / Q000295:instrumentation; D014961:X-Ray Diffraction / Q000295:instrumentation; D017641:Zeolites / Q000494:pharmacology*
D017641:Zeolites