Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Reexamination Certificate
2000-04-28
2001-10-16
Higel, Floyd D. (Department: 1626)
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
C548S545000, C548S546000
Reexamination Certificate
active
06303795
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a method for removing organic contamination from soils, involving the use of a certain surfactant-containing composition to facilitate the removal.
Removal of organic contaminants or pollutants from soil is of great concern. Conventional pump-and-treat remediation, however, has met with limited success, often due to the presence of residual saturated domains of contaminant or strong sorption of the contaminant onto soil components.
Surfactants have been employed in an attempt to enhance subsurface remediation. A review of such techniques has been published by Sabatini et al., “Emerging Technologies in Surfactant-Enhanced Subsurface Remediation,” ACS Symposium Series 594, Surfactant-Enhanced Subsurface Remediation, 1995, pages 1-6.
Details of surfactant selection for such use, especially for removal of chlorinated organic contaminants, has been published by Shiau et al., “Surfactant Selection for Optimizing Surfactant-Enhanced Subsurface Remediation,” pages 65-79 of the aforementioned ACS Symposium Series 594. This reference discloses that surfactants can improve subsurface remediation by solubilization (increasing the aqueous concentration of the contaminant by partitioning into surfactant micelles) or microemulsification (formation of a middle phase microemulsion with concomitant ultra-low interfacial tensions.) The high performance surfactants which were utilized are alkyl diphenyloxide disulfonates from the DOWFAX™ series, ranging from 10 to sixteen carbons in the alkyl group. Surfactant type (structure) is disclosed to be critical to achieving microemulsification systems, unlike solubilization systems where enhancement is relatively independent of surfactant type. Advantages of the DOWFAX™ surfactants include their resistance to precipitation in the presence of calcium ion and minimal susceptibility to sorption losses. Reference to this article can be made for detailed information relative to the theory and practice of various types of micellar and middle-phase systems involving surfactants, useful concentrations, their preparations, and their relative advantages.
A variety of surfactants are known for industrial and other applications. U.S. Pat. No. 4,664,834, Forsberg, May 12, 1987, discloses a water-dispersible reaction product of (A) at least one compound represented by the formula
herein R is a hydrocarbyl group of from about 8 to about 40 carbon atoms, with (B) at least one water-dispersible amine terminated poly(oxyalkylene). Aqueous concentrates and water-based functional fluid comprising these compositions are also disclosed. These reaction products are useful as shear-stable thickeners for such functional fluids.
SUMMARY OF THE INVENTION
The present invention provides a method for remediating soil which is contaminated by one or more organic chemicals, comprising:
(a) contacting the contaminated soil with an aqueous composition comprising a surfactant represented by the structure
(R—X—)
n
—W
where;
each R is independently a hydrocarbyl group containing at least 8 carbon atoms,
n is at least 1,
W is a group containing at least 6 carbon atoms and at least one ether linkage for every 6 carbon atoms thereof, and
each X is selected from the group consisting of
where:
each Y is independently —O— or —NR′—,
each Z is independently OM or NR′
2
,
each R′ is independently hydrogen or a C
1
to C
18
alkyl group,
M is hydrogen, a monovalent metal or one valence of a polyvalent metal, a quaternary ammonium ion, a C
1
to C
18
alkyl group, or —(CH
2
CHR″O)
a
—H, where R″ is hydrogen or a methyl group and a is 1 to 40;
wherein the group X is connected to the group W through the group Y or —NR′—;
whereby at least a portion of said hydrophobic organic chemicals become associated with said aqueous composition.
Thereafter the aqueous composition and organic chemicals associated therewith can be removed from the soil, or they can be decontaminated by a biological process.
The present invention further provides surfactants suitable for such use, including a composition represented by the structure
(R—X—)
n
—W
where:
n is 1;
R is independently a hydrocarbyl group containing at least 8 carbon atoms,
W is a group containing at least 6 carbon atoms and at least one ether linkage for every 6 carbon atoms thereof, having no unreacted amino groups
and where X is selected from the group consisting of
where:
Y is —O— or —NR′—,
Z is OM or NR′
2
,
each R′ is independently hydrogen or a C
1
to C
18
alkyl group,
M is hydrogen, a monovalent metal or one valence of a polyvalent metal, a quaternary ammonium ion, a C
1
to C
18
alkyl group, or —(CH
2
CHR″O)
a
—H, wherein a is 1 to 40 and R″ is hydrogen or a methyl group;
wherein the group X is connected to the group W through the group Y or —NR′—.
DETAILED DESCRIPTION OF THE INVENTION
In the process of the present invention, the term “soil” is used in a generic sense to refer to the various materials which can be encountered in the earth and which can be the subject of contamination. Soil, therefore, includes rocks, sand, gravel, clays, silt, humus, loess, and other such components, alone or in combination, and including varying amounts of water which may be found in the presence of such components, as is found in the ground. The particular composition of soil varies from location to location in a way which is widely recognized and is well known to those skilled in the art. The particular type of soil for which the present invention is suitable is not particularly limited. For testing and evaluation purposes, a standard soil known as “Canadian River Alluvium,” consisting of 72% sand, 27% silt and clay (on a dry basis), and an organic carbon content of 0.07%, is sometimes employed.
Soil can be contaminated by a variety of exogenous organic materials. The contaminants can be associated with the solid components of the soil or the water component of the soil (i.e., groundwater) or both. These contaminants are often characterized by a greater or lesser degree of hydrophobicity, water insolubility, and sometimes a tendency sorb to various soil components. These properties make remediation of the soil more difficult. Common contaminants include crude oils, that is, mineral oils, petroleum, solvent or acid treated mineral oils, and oils derived from coal or shale. Synthetic oils can also be contaminants: these include hydrocarbon oils, halo-substituted hydrocarbon oils, alkylene oxide polymers, esters of dicarboxylic acids and polyols, esters of phosphorus-containing acids, polymeric tetrahydrofurans and silicon-based oils. Also included are crude oil fractions and refined hydrocarbons such as gasolines, kerosene, diesel fuel, and fuel oil. Also included are commercial oil-containing compositions, such as motor oils and other lubricants, transmission fluids, and hydraulic fluids.
Other common organic contaminants include halogenated hydrocarbons, commonly chlorinated hydrocarbons, which are sometimes used as solvents or synthetic lubricants. Examples of chlorinated organic contaminants include solvents such as tetrachloroethylene, trichloroethylene, and trans-1,2-dichlorethylene. Other contaminants can include aromatic substances such as benzene, toluene, and naphthalene, as well as various aliphatic hydrocarbons.
The foregoing contaminants may be associated with the solid soil particles, with the water component of the soil, or in any combination thereof.
An important component of the present invention is the surfactant. The surfactant is represented by the structure (R—X—)
n
—W. The expression “represented by the structure” is meant to include obvious variants and equivalent of a given structure, including isomers, tautomers, and the like. In the structure above, each R is independently a hydrocarbyl group containing at least 8 carbon atoms, and preferably up to 40 carbon atoms. Preferably each R is an alkyl group of 12 to 32, or more preferably 16 to 18 carbon atoms. The R groups are intended to provide a measure of
Grisso Bryan A.
Jahnke Richard W.
Esposito Michael F.
Higel Floyd D.
Shold David M.
The Lubrizol Corporation
LandOfFree
Succinimide-based surfactant suitable for soil remediation does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Succinimide-based surfactant suitable for soil remediation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Succinimide-based surfactant suitable for soil remediation will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2613014