Techniques to remediate VOC´s -  Volatile Organic Compounds

Selection of any clean-up technique is always determined based on many characteristics such as the contamination level, geological and hydro-geological settings as well as physical and chemical conditions on site. The following techniques are used for soil and groundwater remediation:

Soil vapor extraction wells will be installed to remediate contaminated soil.

Vacuum pumps extract contaminated soil gas from the wells which then is filtered by activated carbon units. VOCs will be adsorbed by activated carbon and clean air leaves the treatment system. A groundwater treatment system ("stripper") is operating by feeding air in counter-current flow to contaminated ground water. In this process VOCs dissolved in groundwater migrate from liquid phase (groundwater) into the vapor phase (air) based on their physical-chemical characteristics (vapor pressure). The VOC containing air flow now is passing activated carbon filter units where the contaminatns are being absorbed. VOC-loaded activated carbon filter units will be recycled.

If vertical wells can not be installed due to restricted accessibility of contaminated areas (e. g. contamination underneath an occupied building with sensitive usage or a ongoing operation), vertical wells may be installed. Drilling can start outside the building. Electromagnetic measurements will navigate the position of the drilling head to its final position. Treatment of contaminated soil gas and groundwater is conducted similar as described above.

Beside these innovative techniques we have also implemented drainage systems for hydraulic remediation of groundwater. Water entering the drainage system is pumped and sent to a treatment system using stripping processes and active carbon for the final clean-up process.