Evaluation of cement degradation induced by the metabolic products of two fungal strains
Author:
J. V. Perfettini, E. Revertegat and N. Langomazino
Date: 18 July 2012
Abstract:
During their metabolism, microorganisms can produce acids able to bring about the degradation of cement. Two acid-producing alkalophilic fungal strains have been isolated from soil, a strain of Aspergillus niger which produces gluconic and oxalic acid and of Mycelia sterila which produces gluconic and malic acid. After eleven months of contact the acids produced by Aspergillus dissolved portlandite with a low leaching of calcium, increased the cement porosity by 11.4%, and reduced the bending strength by 78%. The second strain is responsible for a significant dissolution of portlandite with a leaching of calcium of 4.2% of the initial content, an increase of the porosity of 11%, and a loss of the bending strength of 62%. Direct contact of mycelia with the cement surface is not necessary for effective dissolution to take place. Low pH and a high temperature favor the production of acids. Key words. Radioactive waste; cement; degradation; microorganisms; organic acids.
Download the full article (Disclaimer)
This manuscript library of ~16,000 articles (1729-2024) related to Aspergillus and aspergillosis is intended for individual study only, and is provided as contribution to global understanding of the topic. Please refer to the publisher’s guidance about any other usage.