Study of the biodegradation mechanisms of cementitious matrices: Application to asbestos cement waste

The process of biodegradation enables to reduce the mass of asbestos cement wastes through the dissolution of the cementitous matrix. A mass loss of 15 to 30% is achieved over one week.

Start: 04 November 2019

End: 25 January 2023

Robin Bonnet

Supervisors :
Eric van Hullebusch, DRAGHI Marjorie

Related themes :
Earth System Science

Status: Defended

Cementitious asbestos materials were widely used during the 20^th century until their ban in France in 1997. Today, millions tons of asbestos-containing cementitious materials remain in situ and represent an upcoming source of wastes. Management methods now authorized for asbestos cement waste are landfilling in specialized facilities (ISDD, ISDND) and treatment through vitrification. Landfilling is usually favored due to the high vitrification cost. The purpose of this PhD is to study a process suitable to reduce the weight of asbestos cement wastes through the bio-degradation of the alkaline matrix of fibrocement, which represents about 50% of their mass. The purpose of this PhD is to study a process suitable to reduce the weight of asbestos cement wastes through the bio-degradation of the alkaline matrix of fibrocement, which represents about 50% of their mass. Degradation is carried out by acid solutions provided by lactic acid fermentation from agro-industrial effluents rich in carbohydrates. For this purpose, a microbial strain has been isolated to carry out the lactic fermentation under mesophilic conditions (30°C), biodegradation experiments of asbestos cement wastes have been achieved, and the experimental results were used to model the material degradation.

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Biogeochemistry at the Antropocene of Elements and Emerging Contaminants

Cementitious asbestos materials were widely used during the 20th century until their ban in France in 19...

Earth System Science

Measuring, understanding and modelling the functioning of our planet's surface, also called the Critical Zone.