If contaminated soils cannot be excavated or excavation is too complex to be conducted, soil &and groundwater can be remediated by in situ remediation. Many in situ remediation techniques can be applied but from sustainability and cost efficiency point of view, biological remediation techniques are most often preferred. Given the complexity of in situ remediation techniques, a biological approach is often combined with other in situ remediation techniques like (L/D)NAPL removal, soil vapor extraction, Pump & Treat, chemical oxidation, bio-augmentation, biotensides,... etc.
Biological in situ remediation
A biological in situ remediation can be implemented in various ways: for example, the necessary nutrients can be distributed by direct push injection or alternatively by groundwater flushing. Which approach is best practice, differs from site to site, type of contamination and geology.
In the area of chlorinated solvents (cVOC) and MTBE degradation, GreenSoil has a partnership with Xeramics International NV (subsidiary of Punch) which owns the commercial license of a patented technique (Vito). The patent includes the aboveground breeding and augmentation of the soil with specific cVOC degrading bacteria in combination with dosing the suited electron donor and/or nutrients. The patent also involves the design of MTBE specific bioreactors in which specific MTBE degrading bacteria are breaded, resulting in high removal efficiencies for MTBE impacted groundwater. This method can also be applied in situ.