Influence of bacteria inoculum and organic concentration on the biodegradation of soil conditioning agents in aqueous solutions

Earth Pressure Balance (EPB) technology is currently the most widely used technique in mechanized tunnelling with Tunnel Boring Machines (TBMs) and particularly in urban en-vironments, because of several advantages, as the possibility to excavate in different geo-logical conditions and effectively controlling the induced effects on the pre-existing struc-tures. EPB technology requires the continuous injection of chemicals during the advance-ment: this may induce the accumulation of xenobiotic compounds in the excavated debris. The present work aims at studying the role of several parameter, as dosage of conditioning agents and environmental conditions, in the biodegradation process through the develop-ment of an experimental activity involving the use of commercial soil conditioning agents. Results provide elements useful to improve the knowledge of the interaction phenomena between the soil and the chemicals, the management of excavated soil and the design of the environmental monitoring activity.