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Title: Situ treatment of contaminated groundwater

Abstract

A system for treating dissolved halogenated organic compounds in groundwater that relies upon electrolytically-generated hydrogen to chemically reduce the halogenated compounds in the presence of a suitable catalyst. A direct current is placed across at least a pair, or an array, of electrodes which are housed within groundwater wells so that hydrogen is generated at the cathode and oxygen at the anode. A pump is located within the well housing in which the cathode(s) is(are) located and draws in groundwater where it is hydrogenated via electrolysis, passes through a well-bore treatment unit, and then transported to the anode well(s) for reinjection into the ground. The well-bore treatment involves a permeable cylinder located in the well bore and containing a packed bed of catalyst material that facilitates the reductive dehalogenation of the halogenated organic compounds by hydrogen into environmentally benign species such as ethane and methane. Also, electro-osmatic transport of contaminants toward the cathode also contributes to contaminant mass removal. The only above ground equipment required are the transfer pipes and a direct circuit power supply for the electrodes. The electrode wells in an array may be used in pairs or one anode well may be used with a plurality ofmore » cathode wells. The DC current flow between electrode wells may be periodically reversed which controls the formation of mineral deposits in the alkaline cathode well-bore water, as well as to help rejuvenate the catalysis.

Inventors:
 [1];  [2];  [3]
  1. (Concord, CA)
  2. Tracy, CA
  3. Livermore, CA
Issue Date:
Research Org.:
Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
OSTI Identifier:
873659
Patent Number(s):
6214202
Assignee:
Regents of University of California (Oakland, CA)
Patent Classifications (CPCs):
B - PERFORMING OPERATIONS B09 - DISPOSAL OF SOLID WASTE B09C - RECLAMATION OF CONTAMINATED SOIL
C - CHEMISTRY C02 - TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE C02F - TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
situ; treatment; contaminated; groundwater; treating; dissolved; halogenated; organic; compounds; relies; electrolytically-generated; hydrogen; chemically; reduce; presence; suitable; catalyst; direct; current; placed; pair; array; electrodes; housed; generated; cathode; oxygen; anode; pump; located; housing; draws; hydrogenated; via; electrolysis; passes; well-bore; unit; transported; reinjection; ground; involves; permeable; cylinder; bore; containing; packed; bed; material; facilitates; reductive; dehalogenation; environmentally; benign; species; ethane; methane; electro-osmatic; transport; contaminants; contributes; contaminant; mass; removal; equipment; required; transfer; pipes; circuit; power; supply; electrode; pairs; plurality; dc; flow; periodically; reversed; controls; formation; mineral; deposits; alkaline; water; help; rejuvenate; catalysis; chemically reduce; contaminated groundwater; packed bed; catalyst material; environmentally benign; organic compound; direct current; organic compounds; power supply; current flow; halogenated organic; dc current; periodically reversed; situ treatment; halogenated compounds; mineral deposit; cylinder located; /205/204/588/

Citation Formats

McNab, Jr., Walt W., Ruiz, Roberto, and Pico, Tristan M. Situ treatment of contaminated groundwater. United States: N. p., 2001. Web.
McNab, Jr., Walt W., Ruiz, Roberto, & Pico, Tristan M. Situ treatment of contaminated groundwater. United States.
McNab, Jr., Walt W., Ruiz, Roberto, and Pico, Tristan M. Mon . "Situ treatment of contaminated groundwater". United States. https://www.osti.gov/servlets/purl/873659.
@article{osti_873659,
title = {Situ treatment of contaminated groundwater},
author = {McNab, Jr., Walt W. and Ruiz, Roberto and Pico, Tristan M},
abstractNote = {A system for treating dissolved halogenated organic compounds in groundwater that relies upon electrolytically-generated hydrogen to chemically reduce the halogenated compounds in the presence of a suitable catalyst. A direct current is placed across at least a pair, or an array, of electrodes which are housed within groundwater wells so that hydrogen is generated at the cathode and oxygen at the anode. A pump is located within the well housing in which the cathode(s) is(are) located and draws in groundwater where it is hydrogenated via electrolysis, passes through a well-bore treatment unit, and then transported to the anode well(s) for reinjection into the ground. The well-bore treatment involves a permeable cylinder located in the well bore and containing a packed bed of catalyst material that facilitates the reductive dehalogenation of the halogenated organic compounds by hydrogen into environmentally benign species such as ethane and methane. Also, electro-osmatic transport of contaminants toward the cathode also contributes to contaminant mass removal. The only above ground equipment required are the transfer pipes and a direct circuit power supply for the electrodes. The electrode wells in an array may be used in pairs or one anode well may be used with a plurality of cathode wells. The DC current flow between electrode wells may be periodically reversed which controls the formation of mineral deposits in the alkaline cathode well-bore water, as well as to help rejuvenate the catalysis.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2001},
month = {1}
}