Soil and ground-water restoration by steam enhanced extraction
- Univ. of California, Berkeley, CA (United States). Environmental Restoration Lab., Dept. of Mechanical Engineering
The acceleration of recovery rates of second phase liquid contaminants from the subsurface during gas or water pumping operations is realized by increasing the soil and ground-water temperature. Several methods of delivery of thermal energy to soils and ground water are possible. Of these methods, steam injection combined with ground-water pumping and vacuum extraction appears to be the most economical and versatile technique to recover volatile, semivolatile, and nonvolatile contaminants from the subsurface. One-dimensional experiments have shown effective removal of both volatile and semivolatile second liquid phase chemicals, and nonvolatile aqueous phase contaminants from sand packs. Two-dimensional experiments with homogeneous and layered sand packs have shown rapid recovery of semivolatile hydrocarbon liquids and dense chlorinated solvents. The enhancement of mass transfer from lower permeability regions during the depressurization mode of operation has been observed. As a result of these experiments, several mechanisms have been identified which account for the observed removal of the contaminants. These are vaporization of components with low boiling points, enhanced evaporation rates of semivolatile components, physical displacement of low viscosity liquids, dilution and displacement of aqueous contaminants, and removal of residual contaminants by vacuum drying. Field-scale studies of steam injection and vacuum extraction confirm the effectiveness of this technique and its applicability to contaminants found above and below the water table.
- OSTI ID:
- 6014958
- Report Number(s):
- CONF-9310166--
- Journal Information:
- Ground Water; (United States), Journal Name: Ground Water; (United States) Vol. 31:5; ISSN GRWAAP; ISSN 0017-467X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
540250* -- Environment
Terrestrial-- Site Resource & Use Studies-- (1990-)
CLEANING
DECONTAMINATION
EXTRACTION
FLUID INJECTION
GROUND WATER
HYDROCARBONS
HYDROGEN COMPOUNDS
MANAGEMENT
MATERIALS RECOVERY
ORGANIC COMPOUNDS
ORGANIC SOLVENTS
OXYGEN COMPOUNDS
PROCESSING
SEPARATION PROCESSES
SOILS
SOLVENTS
STEAM INJECTION
TECHNOLOGY ASSESSMENT
WASTE MANAGEMENT
WASTE PROCESSING
WATER