Nontoxic chemical process for in situ permeability enhancement and accelerated decontamination of fine-grain subsurface sediments

Patent · Wed Jan 01 00:00:00 EST 1997

OSTI ID:870778

Kansa, Edward J ^[1]; Wijesinghe, Ananda M ^[2]; Viani, Brian E ^[3]

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1. Livermore, CA
2. Tracy, CA
3. Oakland, CA

The remediation of heterogeneous subsurfaces is extremely time consuming and expensive with current and developing technologies. Although such technologies can adequately remove contaminants in the high hydraulic conductivity, coarse-grained sediments, they cannot access the contaminated low hydraulic conductivity fine-grained sediments. The slow bleed of contaminants from the fine-grained sediments is the primary reason why subsurface remediation is so time-consuming and expensive. This invention addresses the problem of remediating contaminated fine-grained sediments. It is intended that, in the future, a heterogeneous site be treated by a hybrid process that first remediates the high hydraulic conductivity, coarse-grained sediments, to be followed by the process, described in this invention, to treat the contaminated low hydraulic conductivity fine-grained sediments. The invention uses cationic flocculents and organic solvents to collapse the swelling negative double layer surrounding water saturated clay particles, causing a flocculated, cracked clay structure. The modification of the clay fabric in fine-grained sediments dramatically increases the hydraulic conductivity of previously very tight clays many orders of magnitude.

• 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 5593248
• OSTI ID: 870778
• Country of Publication: United States
• Language: English

Related Subjects

nontoxic
chemical
process
situ
permeability
enhancement
accelerated
decontamination
fine-grain
subsurface
sediments
remediation
heterogeneous
subsurfaces
extremely
time
consuming
expensive
current
developing
technologies
adequately
remove
contaminants
hydraulic
conductivity
coarse-grained
access
contaminated
fine-grained
slow
bleed
primary
reason
time-consuming
addresses
remediating
intended
future
site
treated
hybrid
remediates
followed
described
treat
cationic
flocculents
organic
solvents
collapse
swelling
negative
double
layer
surrounding
water
saturated
clay
particles
causing
flocculated
cracked
structure
modification
fabric
dramatically
increases
previously
tight
clays
magnitude
hydraulic conductivity
organic solvents
organic solvent
double layer
chemical process
remove contaminants
surrounding water
time consuming
toxic chemical
subsurface sediment
layer surrounding
/405/166/