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Title: Dynamic underground stripping: steam and electric heating for in situ decontamination of soils and groundwater

A dynamic underground stripping process removes localized underground volatile organic compounds from heterogeneous soils and rock in a relatively short time. This method uses steam injection and electrical resistance heating to heat the contaminated underground area to increase the vapor pressure of the contaminants, thus speeding the process of contaminant removal and making the removal more complete. The injected steam passes through the more permeable sediments, distilling the organic contaminants, which are pumped to the surface. Large electrical currents are also applied to the contaminated area, which heat the impermeable subsurface layers that the steam has not penetrated. The condensed and vaporized contaminants are withdrawn by liquid pumping and vacuum extraction. The steam injection and electrical heating steps are repeated as necessary. Geophysical imaging methods can be used to map the boundary between the hot, dry, contamination-free underground zone and the cool, damp surrounding areas to help monitor the dynamic stripping process.
Inventors:
 [1];  [2];  [2];  [3];  [1];  [1]
  1. (Livermore, CA)
  2. (Pleasanton, CA)
  3. (Berkeley, CA)
Issue Date:
OSTI Identifier:
870058
Assignee:
Regents of University of California (Oakland, CA) LLNL
Patent Number(s):
US 5449251
Contract Number:
W-7405-ENG-48
Research Org:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Country of Publication:
United States
Language:
English
Subject:
dynamic; underground; stripping; steam; electric; heating; situ; decontamination; soils; groundwater; process; removes; localized; volatile; organic; compounds; heterogeneous; rock; relatively; time; method; injection; electrical; resistance; heat; contaminated; increase; vapor; pressure; contaminants; speeding; contaminant; removal; complete; injected; passes; permeable; sediments; distilling; pumped; surface; currents; applied; impermeable; subsurface; layers; penetrated; condensed; vaporized; withdrawn; liquid; pumping; vacuum; extraction; steps; repeated; geophysical; imaging; methods; map; boundary; hot; dry; contamination-free; zone; cool; damp; surrounding; help; monitor; stripping process; steam injection; electrical heating; contaminant removal; situ decontamination; resistance heating; organic contaminant; organic compound; organic compounds; vapor pressure; electrical resistance; electrical current; surface layer; volatile organic; organic contaminants; surface layers; imaging method; electrical currents; electrical heat; electric heat; heating step; process removes; dynamic underground; underground stripping; resistance heat; /405/166/