Situ treatment of contaminated groundwater

Patent · Mon Jan 01 00:00:00 EST 2001

OSTI ID:873659

Ruiz, Roberto ^[1]; Pico, Tristan M ^[2]

---

1. Tracy, CA
2. Livermore, CA

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.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
• DOE Contract Number: W-7405-ENG-48
• Assignee: Regents of University of California (Oakland, CA)
• Patent Number(s): US 6214202
• OSTI ID: 873659
• Country of Publication: United States
• Language: English

Related Subjects

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/