In-Situ Thermal Remediation Service
In-situ remediation with electric heating elements for cleaning soil contaminated with VCHCs. In-situ thermal remediation (ISTR) of an VCHC contamination on the site of a former chemical cleaning facility using fixed, electrically operated heat sources and soil vapor extraction. The subsoil has a very inhomogeneous structure and low permeability. The VCHCs were located in the unsaturated soil layer at a depth of up to 15 m below ground level. The heating of the soil body and the extraction of the CHCs took place over an area of approx. 1,000 m². The outflow was hydraulically secured with the aid of a groundwater treatment plant. The remediation was successfully completed and the remediation objectives were achieved.
Sector/client
- SBB- Swiss Federal Railway
Particularities
- Limited space
- Remediation area near railroad tracks and residential buildings: therefore increased requirements for electrical installations and noise protection
- Potential settlement processes require a high standard of process monitoring
Characteristics
- Pollutants: VCHCs, almost exclusively PCE
- Floor air extraction
- Volume flow 1,100 m³/h
- Negative pressure up to 300 mbar
- Groundwater purification system
- Flow rate max. 25 m³/h
- Installed heating capacity 730 kW
- 350 kW cooling capacity
- Removal approx. 210 kg of pollutant (corresponds to approx. 95 % of the inventory)
Services offered
- ISTR remediation
- 194 drill holes for:
- 60 electrical heating elements
- 56 soilr air extraction levels
- 77 temperature lances
- Soil air treatment: Air activated carbon filter
- Ground water treatment system
- Sand filter, water activated carbon filter
- Telecontrol technology, process visualization
- Supply and operation of heating and measurement technology
- Supply and operation of the two-stage soil vapor extraction system and soil vapor treatment via air activated carbon filter
Service period
- March 2020 to December 2022