Susceptibility of polysiloxane and colloidal silica to degradation by soil microorganisms

摘要

This report is a description of the laboratory study undertaken to determine the biodegradability of Colloidal Silica (CS) and PolySiloXane (PSX), a new generation of barrier liquids employed by the Viscous Liquid Barrier (VLB) technology in the containment of subsurface contaminants. Susceptibility of either material to microbial degradation would suggest that the effectiveness of a barrier in the subsurface may deteriorate over time. Degradation may result from several different biological events. Organisms may consume the material as a carbon and/or energy source, organisms may chemically change the material as a detoxification mechanism, or organisms may erode the material by their physical penetration of the material during growth. To determine if degradation occurs, physical interactions between soil microbes and the barrier materials were analyzed, and the metabolic activity of individual organisms in the presence of CS and PSX was measured.