MICROBIALLY INFLUENCED DEGRADATION OF CEMENT-BASED MATERIALS IN BIOGAS PRODUCTION ENVIRONMENTS

Author(s): Voegel, C., Bertron, A. and Erable, B.
Paper category: Conference
Book title: XIII International Conference on Durability of Building Materials and Components - XIII DBMC
Editor(s): Marco Quattrone, Vanderley M. John
Print ISBN: none
e-ISBN: 978-2-35158-149-0
Publication year: 2015
Pages: 727-736
Total Pages: 10
Language: English

Abstract: In biogas production plants (digesters), concrete structures suffer severe chemical and biological attacks at every step of the anaerobic digestion process. The attack on concrete may be linked to the synergetic effect of (i) organic acids, (ii) CO2 co-produced by the metabolic activity of microorganisms and (iii) the presence of the bacteria themselves and their ability to form biofilms on the concrete surface. Combined with mechanical action, the consequences on concrete are loss of alkalinity, drop in mechanical strength, progressive erosion and the loss of air/water-tightness, which rapidly decrease the durability of the concrete structures. In a context of significant expansion of the biogas industry, the mechanisms of concrete deterioration need to be better understood with the goal of proposing new, efficient solutions (protection, formulation, etc.).

This study aims, firstly, to characterise the evolution of the biodegradable wastes in terms of biochemical composition during the process of digestion in order to identify the conditions that produce the most aggressive conditions for concrete. Secondly, it aims to evaluate the mechanisms of concrete deterioration in different situations (storage, treatment, etc.) and to distinguish the role of microorganisms from that of the microbial metabolites.

The biowaste samples were collected from a farm-sized biogas plant at different stages of the digestion process. The solid and liquid fractions were analysed chemically and microbiologically. Cement pastes were then immersed either in the raw effluents, or in synthetic organic wastes, the input composition of which was well known. The mechanisms of alteration were investigated using XRD, EPMA and SEM analysis.

Online publication: 2015
Publication Type: full_text
Public price (Euros): 0.00