In-Situ Thermal Desorption (ISTD)
Together with our partners Reconsite GmbH, Cornelsen offers in-situ conductive heating. Particularly well suited to lower permeability cohesive soils the substrate is heated directly by the installation of electric heaters. Contaminants which are liquids at normal temperatures evaporate quickly into the gaseous phase where they are recovered by a soil vapour extraction (SVE) system. The water/pollutant mix ensures this occurs well below 100 oC. Accordingly, despite a 600 oC maximum heating capacity in the heater elements, deploying the maximum possible heat (and therefore kW) is rarely required.
The inclusion of temperature monitoring points distributed vertically and laterally throughout the formation along with an in-line GC-FID and remote telemetry enables Reconsite to provide daily advice and recommendations as required. We emphasise that neither Cornelsen nor Reconsite are offering a turnkey remediation service. Final design and on site operation will be undertaken by you with support from and maintenance by Cornelsen Ltd and Reconsite. All and any design relating to the steam sparging network will be undertaken between you and Reconsite along with any on-going monitoring and performance optimisation.
Recent UK projects include a steam sparging project undertaken simultaneously with conductive heating in alternate vertical horizons. This project was undertaken together with AECOM and Tamdown Regeneration and was “highly commended” in the 2011 Brownfield Awards. The project included the use of high temperature pneumatic total fluids pumps for de-watering, SVE, high vacuum, multi-phase extraction, heat exchange and groundwater and vapour treatment systems.
Click here for a Case Study which included steam injection combined with ISTD