Periodic Reporting for period 1 - CEBREWA (Construction & Environmental Biocementation in REal World Applications)
Reporting period: 2021-02-01 to 2022-07-31
Ground stabilization mitigates stability risks associated with geohazards, such as soil liquefaction during earthquakes, soil erosion, and landslides. Such problems, which are expected to be further intensified by extreme weather and aging infrastructure, are traditionally solved via soil injections with cement or other chemical products. The novelty of ground consolidation through bio-cementation has been widely recognized but certain bottlenecks hinder its further commercialization. These are related to the residual nitrogen concentrations and the absence of a framework to design, predict and execute targeted soil injections. There is therefore a market and technological gap between the structural or environmental requirements for ground stabilization and available technologies based on bio-cementation. The ERC PoC CEBREWA aimed at addressing the challenges of eliminating unwanted nitrogen from the involved reactions and improving the predictability and monitoring of bio-cementation. By introducing a fully circular system based on bioreactors, we extract ammonium safely and provide a carbon-rich solution at pH values which are in the same range as those of natural soils. This significantly reduces manufacturing costs as ammonia can be revalorized, and allows for obtention of the necessary environmental certificates. We finally developed a numerical toolbox to show the versatility of the technique when operating under various injection procedures and geologies. The technological readiness and reliability of such numerical model predictions are now a reality and they are believed to serve future conception and realization of bio-cementation in earthworks.