Multi-phase extraction involves extracting both the contaminated groundwater and soil-vapor simultaneously, from the same extraction well, using a high-vacuum pump. Extracting groundwater depresses the water table, thereby exposing contaminated soil while vapor extraction aids in the remediation of this soil by removing contaminated vapors and promoting biodegradation.
In a multi-phase extraction (or dual-phase extraction) system, a high-vacuum pump creates a large negative pressure in the well. The combined groundwater and vapor streams are consolidated at the system via a manifold. A vapor/liquid separator separates the contaminated water and vapor, and each stream is treated individually. The groundwater treatment technologies employed are dependent on the contaminants and required discharge quality. A typical treatment chain for petroleum contamination might consist of an oil/water separator, an air stripper, and activated carbon vessels. The effluent vapor is either discharged or treated, using activated carbon or an oxidizer, and then discharged.
Considerations in the design of a multi-phase extraction system include: the number of extraction wells, required air and water flow rates, required vacuum, levels of contaminants, and discharge requirements. Depending on the site conditions and contaminants, a number of high-vacuum pumps and vapor and liquid treatment technologies are available.
Please follow the links to view the various types of equipment used in multi-phase extraction systems.
