Method for soil remediation

A process of soil remediation in which an encapsulation solution is introduced into contact with a soil matrix containing chemical contaminants such as polynucleated aromatics chloronated hydrocarbons and the like in an amount sufficient to form a saturated admixture of the soil matrix and the encapsulation solution, the encapsulation solution being capable of preferentially attracting the chemical contaminants contained in the soil matrix, and containing an effective amount of non-ionic surfactant material, an anionic surfactant material and water; and the admixture is admixed for an interval sufficient to permit the chemical contaminants to preferentially dissociate from contact with the soil matrix in favor of association with the encapsulation solution and at least one carbon bond in the chemical contaminant to be broken as a result of interaction between the non-ionic surfactant material and the contaminant. Once this occurs, a major portion of the encapsulation solution with associated chemical contaminants can be removed from contact with the soil matrix.

The present invention relates to chemical remediation. More specifically, 
the present invention pertains to a method and apparatus which can be 
employed to reduce or eliminate undesirable chemical contaminants from 
fluidizable matrices such as soil by bioencapsulation of at least a 
portion of the contaminants and chemically straining or breaking chemical 
bonds present in the contaminates rendering them amenable to subsequent 
chemical, environmental and biological degradation. 
BACKGROUND OF THE INVENTION 
In the past two decades, the problem of soil contamination has been 
recognized as being pronounced, extensive and acute; both in the United 
States and abroad. Clean-up of both accidentally and intentionally 
contaminated soil has been mandated by federal, state, and local 
governments. The complexity of the task of soil remediation is compounded 
by the wide variation among contaminated sites. It cannot be guaranteed 
that any two clean-up sites will contain soil having the same 
characteristics; be exposed to similar climatic or geological conditions; 
or even have similar chemical contaminants present at even roughly the 
same concentrations. Wide variations can occur from site to site or even 
from location to location within the same clean-up site. 
Thus the methodology for each clean-up effort must be specifically designed 
to meet the conditions found at the given site. Various processing methods 
implemented in the past have met with limited success. Volatile or 
volatilizable contaminants can be removed by a variety of reactive or 
evaporative processes. These processes generally entail the use of 
absorbent and/or oxidizing reactant materials which react with volatile or 
volatilizable organics to form reaction by-products which are more 
environmentally acceptable than the original contaminants. Such systems 
generally entail heating the soil matrix or subjecting it to other 
physical procedures to volatilize the contaminants to remove them from the 
soil matrix. 
Many chemical contaminants are not readily volatilizable and therefore are 
not amenable to the reactive and/or evaporative processes as previously 
described. These contaminants include, but are not limited to halogenated 
aliphatics and various substituted and non-substituted poly-and 
mono-aromatic hydrocarbons; for example, polyhalogenated biphenyls and the 
like. Irradiation of contaminated solid material such as soil has been 
proposed as a method for reducing certain specific contaminants; for 
example polyhalogenated biphenyls such as PBB and PCB. However, such 
procedures are costly and time consuming. Such treatment methods are of 
limited use for use in soil matrices containing high concentrations of a 
wide variety of contaminants. 
Extraction processes have been proposed to remove chemical contaminants 
from soil and sludge. Such methods generally involve contacting water wet 
soil/sludge with suitable water-insoluble solvents in which the chemical 
contaminants are preferentially soluble. The solvent containing the 
contaminants are separated from the solid after which the solvent and 
contaminants may then be separated from one another and a suitable 
post-treatment process. 
Because no universally effective remediation method has been proposed, 
on-site soil remediation has been essentially impossible in many cases. 
Clean-up and remediation efforts up to the present have concentrated on 
removal of contaminated soil from the site to either secure containment 
landfills or to incineration facilities. This is both expensive and 
sacrifices productive topsoil which, if remediated, could possibly support 
vegetative growth. 
It would be highly desirable to provide a remediation method which could be 
employed effectively with a variety of different contaminated matrices 
such as water, soil, bio-solids, and the like to remove a variety of 
classes of chemical contaminants. It is also desirable to provide a 
process in which chemical contaminants, particularly any which may remain 
in the soil as post-treatment residue are rendered amenable to further 
chemical, biological or environmental degradation. It is also desirable 
that the contaminant removal process be one which can be accomplished in a 
continuous manner at or near the clean-up site. Furthermore it is 
desirable that the remediation process be one which is capable of reducing 
the level of contaminants present in various matrices, particularly in 
soil to a level below that which is mandated in the applicable 
environmental regulations, with reduction in contaminant concentrations to 
levels below current detection limits being highly desirable. 
SUMMARY OF THE INVENTION 
The present invention is a process and device for remediation either on or 
near the source of the contaminated matrix material or at locations remote 
therefrom in which significant portions of various organic compounds 
classified as target chemical contaminants can be removed from association 
with the matrix in a manner which ultimately is capable of reducing the 
concentration of these target organic contaminants to levels at or below 
those mandated by the applicable state, local, or federal environmental 
regulatory agencies. If desired, the process of the present invention can 
be employed to reduce the levels of target chemical contaminants to levels 
below the detection limits of analytical instruments currently employed. 
The contaminated matrix may be a liquid material, such as underground or 
above-ground water, or fluidizable solid materials such as soil, 
bio-solids and the like. While the remediation process of the present 
invention is described in particular as it relates to soil processing, it 
is to be understood that the process of the present invention may be 
successfully employed on other fluid or fluidizable contaminated media 
such as bio-solids, water and the like. 
In the remediation process of the present invention, a quantity of an 
encapsulation solution sufficient to saturate the matrix to be treated is 
brought into contact with material containing targeted chemical 
contaminants. The encapsulation solution employed is capable of 
preferentially attracting the target chemical contaminants contained in 
the matrix, isolating a significant portion of the target chemical 
contaminants therefrom, and rendering both the isolated contaminants and 
the non-isolated contaminants amenable to decompositional processes. The 
decompositional process may be subsequent chemical processes, 
biodegradation, and environmental degradation either independently or in 
any combination thereof. The encapsulation solution employed in the 
remediation process consists essentially of a non-ionic surfactant 
material employed alone, or preferably, in combination with a sequestering 
agent such as an anionic, cationic and/or amphoteric surfactant material. 
It is believed that the encapsulation solution employed in the remediation 
process of the present invention performs its function, at least in part, 
by chemically straining or breaking bonds present in the target chemical 
contaminates, or between the target chemical contaminants and the 
contaminated matrix, rendering the target chemical contaminants amenable 
to subsequent chemical, environment and biological degradation or 
bioencapsulation. 
In the preferred embodiment, the admixture resulting from combining 
contaminated matrix and encapsulation solution is agitated for an interval 
sufficient to permit ultimate contact between the encapsulation solution 
and the target chemical contaminants to preferentially dissociate the 
target chemical contaminants from contact with the matrix in favor of 
association with the encapsulation solution. Major portions of the 
encapsulation solution with target chemical contaminants associated 
therewith can be removed from contact with the matrix, yielding a treated 
matrix which is essentially free of target chemical contaminants. 
The soil remediation device of the present invention comprises a mixing 
hopper having at least one pair of counter-rotating mixing blades mounted 
therein. In the preferred embodiment, a shredding pug milling device is 
employed. The device of the present invention also has suitable means for 
soil introduction and means for introducing encapsulation solution into 
the mixing hopper associated therewith.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT 
The present invention is predicated on the discovery that various 
formulations consisting essentially of non-ionic surfactant, a 
sequestering agent such as an anionic surfactant material and water 
effectively reduce or eliminate significant concentrations of chemical 
contaminants present in various matrices. The matrices which can be 
successfully treated in the process of the present invention can be either 
fluids, such as water, or fluidizable materials such as soil. Heretofore, 
it was widely held that such surfactant compositions were effective only 
for fire- control and small-scale surface spill control and containment 
but were largely ineffective on deep, permeated contaminant materials. 
The present invention is a process and apparatus for on-site or remote 
remediation in which large quantities of contaminated matrix are contacted 
with sufficient quantities of a suitable encapsulation solution to provide 
ultimate contact between the matrix and the solution. The encapsulation 
solution consists essentially of a non-ionic surfactant material either 
alone or in combination with a distinct sequestering agent component such 
as an anionic surfactant material and/or amphoteric in water. The 
sequestering agent component employed is one capable of preferentially 
dissociating target chemical contaminants from interaction with the matrix 
and bonding the contaminants to constituents in the encapsulation 
solution. The bonding which takes place may be either chemical or physical 
interaction between the two materials. Such bonding renders the 
contaminants particularly amenable to interaction with the non-ionic 
surfactant material present in the encapsulation which ultimately yields 
compounds which are non-hazardous in nature. The interaction can be either 
chemical bonds in the chemical contaminants or can be a more physical or 
chemical/physical interaction in which chemical bonds are strained such 
that the strained chemical bonds are readily broken by subsequent 
environmental interaction such as that which would occur due to naturally 
occurring UV radiation or the action of biological microbes. 
The matrix to be treated can be any material which is either a fluid such 
as water or fluidizable such as various soils, bio-solids and the like. 
For purposes of discussion herein the matrix treated is soil. 
In the preferred embodiment, the encapsulation solution is introduced into 
contact with the soil to be treated in a manner which insures intimate 
contact between the two materials. After contact is complete, a major 
portion of the encapsulation solution containing at least a portion of the 
target chemical contaminants can be removed by any suitable means and the 
remediated soil reinstalled in the desired location. A portion of the 
encapsulation solution may remain in the soil matrix after reinstallation 
to continue to act on contaminants in situ. 
The encapsulation solution employed in the process of the present invention 
can either contain a non-ionic surfactant material alone or in combination 
with a suitable sequestering agent component. In the preferred embodiment, 
the encapsulation solution is an aqueous material containing sufficient 
concentrations of a sequestering agent component sufficient to interact 
with the targeted chemical contaminants and preferentially dissociate the 
same from contact with the soil matrix together with a non-ionic 
surfactant or mixture of surfactants capable of interacting with the 
targeted chemical contaminants in a manner which results in the breakage 
of at least one chemical bond in the targeted contaminant. 
The non-ionic surfactant material successfully employed herein is a 
compound or compound complex essentially insoluble in water which is 
readily dispersible therein. In the preferred embodiment, the non-ionic 
surfactant is a material which is capable of forming a stable emulsion or 
emulsion-like state in water. 
Suitable non-ionic surfactants include materials having an HLB 
(Hydrophile-Lipophile Balance; the relative simultaneous attraction of an 
emulsifier for two phases of an emulsion system) value between about 0 and 
about 13.5, with values between about 3.5 and about 20.0 being preferred. 
The non-ionic surfactants advantageously employed herein are generally 
polyoxyethylene esters of higher fatty acid having from about 8 to 22 
carbon atoms in the acyl group and from about 8 to 30 ethenoxy unit in the 
oxyethylene portion. Typical products are polyoxyethylene adducts of tall 
oil, rosin acid, stearic and oleic acids, materials derived from 
vegetative fatty oils such as cashew oil, almond oil and the like. 
Additional non-ionic surfactants are the polyoxyethylene condensates of 
higher fatty acid amines and amides having from about 8 to 22 carbon atoms 
in the fatty alkyl or acyl group and about 10 to 30 ethenoxy units in the 
oxyethylene portion. Illustrative products are plant or animal, such as 
cashew fatty acid amines and amides condensed with about 10 to 30 moles of 
ethylene oxide. 
Further suitable non-ionic surfactants which are advantageously employed in 
the encapsulation solution of the present invention are generally the 
polyoxyalkylene adducts of hydrophobic bases wherein the oxygen/carbon 
atom ratio in the oxyalkylene portion of the molecule is greater than 
0.40. Those compositions which are condensed with hydrophobic bases to 
provide a polyoxyalkylene portion having an oxygen/carbon atom ratio 
greater than 0.40 include ethylene oxide, butadiene dioxide and glycidol 
mixtures of these alkylene oxides with each other and with minor amounts 
of propylene oxide, butylene oxide, amylene oxide, styrene oxide, and 
other higher molecular weight alkylene oxides. Ethylene oxide, for 
example, is condensed with the hydrophobic base in an amount sufficient to 
impart water dispersibility or solubility and surface active properties to 
the molecule being prepared. The exact amount of ethylene oxide condensed 
with the hydrophobic base will depend upon the chemical characteristics of 
the base employed and is readily apparent to those of ordinary skill in 
the art relating to the synthesis of oxyalkylene surfactant condensates. 
Typical hydrophobic bases which can be condensed with ethylene oxide in 
order to prepare nonionic surfactants include mono- and polyalkyl phenols, 
polyoxypropylene condensed with a base having from about 1 to 6 carbon 
atoms and at least one reactive hydrogen atom, fatty acids, fatty amines, 
fatty amides and fatty alcohols. The hydrocarbon ethers such as the benzyl 
or lower alkyl ether of the polyoxyethylene surfactant condensates are 
also advantageously employed in the compositions of the invention. 
Among the suitable non-ionic surfactants are the polyoxyethylene 
condensates of alkyl phenols having from about 6 to 20 carbon atoms in the 
alkyl portion and from about 5 to 30 ethenoxy groups in the 
polyoxyethylene radical. The alkyl substituent of the aromatic nucleus may 
be octyl, diamyl, n-dodecyl, polymerized propylene such as propylene 
tetramer and trimer, isoctyl, nonyl, etc. The benzyl ethers of the 
polyoxyethylene condensates of monoalkyl phenols impart good properties of 
the compositions of the invention and a typical product corresponds to the 
formula: 
##STR1## 
Higher polyalkyl oxyethylated phenols corresponding to the formula: 
##STR2## 
wherein R is hydrogen or an alkyl radical having from about 1 to 12 carbon 
atoms, R' and R" are alkyl radicals having from about 6 to 16 carbon atoms 
and n has a value from about 10 to 40, are also suitable as non-ionic 
surfactants. A typical oxyethylated polyalkyl phenol is dinonyl phenol 
condensed with 14 moles of ethylene oxide. 
Other suitable non-ionic surfactants are cogeneric mixtures of conjugated 
polyoxyalkylene compounds containing in their structure at least one 
hydrophobic oxyalkylene chain in which the oxygen/carbon atom ratio does 
not exceed 0.40 and at least one hydrophilic oxyalkylene chain in which 
the oxygen/carbon atom ratio is greater than 0.40. 
Polymers of oxyalkylene groups obtained from propylene oxide, butylene 
oxide, amylene oxide, styrene oxide, mixtures of such oxyalkylene groups 
with each other and with minor amounts of polyoxyalkylene groups obtained 
from ethylene oxide, butadiene dioxide, and glycidol are illustrative of 
hydrophobic oxyalkylene chains having an oxygen/carbon atom ratio not 
exceeding 0.40. Polymers of oxyalkylene groups obtained from ethylene 
oxide, butadiene dioxide, glycidol, mixtures of such oxyalkylene groups 
with each other and with minor amounts of oxyalkylene groups obtained from 
propylene oxide, butylene oxide, amylene oxide and styrene oxide are 
illustrative of hydrophilic oxyalkylene chains having an oxygen/carbon 
atom ratio greater than 0.40. 
Other suitable polyoxyalkylene non-ionic surfactants are the alkylene oxide 
adducts of higher aliphatic alcohols and thioalcohols having from about 8 
to 22 carbon atoms in the aliphatic portion and about 3 to 50 oxyalkylene 
portion. Typical products are synthetic fatty alcohols, such as n-decyl, 
n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-hexadecyl, n-oxtadecyl 
and mixtures thereof condensed with 3 to 50 moles of ethylene oxide, a 
mixture of normal fatty alcohols condensed with 8 to 20 moles of ethylene 
oxide and capped with benzyl halide or an alkyl halide, a mixture of 
normal fatty alcohols condensed with 10 to 30 moles of a mixture of 
ethylene and propylene oxides, a mixture of several fatty alcohols 
condensed sequentially with 2 to 20 moles of ethylene oxide and 3 to 10 
moles of propylene oxide, in either order; or a mixture of normal fatty 
alcohols condensed with a mixture of propylene and ethylene oxides, in 
which the oxygen/carbon atom ratio is less than 0.40 followed by a mixture 
of propylene and ethylene oxides in which the oxygen/carbon atom ratio is 
greater than 0.40 followed by a mixture of propylene and ethylene oxides 
in which the oxygen/carbon atom ratio is greater than 0.40 or a linear 
secondary alcohol condensed with 3 to 30 moles of ethylene oxide, or a 
linear secondary alcohol condensed with a mixture of propylene and 
ethylene oxides, or a linear secondary alcohol condensed with a mixture of 
ethylene, propylene, and higher alkylene oxides. 
When employed independent of anionic surfactants, the preferred non-ionic 
surfactant materials are non-ionic surfactants containing no alcohols or 
glycols which contains fatty acid and fatty acid derivatives. Such 
compounds, as noted, are well known and commercially available as spill 
containment media, such as that sold by S & S Company of Georgia, Inc. 
under the tradename CONTROL SOLVE. The material is a proprietary emulsion 
having the characteristics outlined in Table I. 
TABLE I 
______________________________________ 
Typical Properties of CONTROL SOLVE 228 
______________________________________ 
Boiling Point (at 760 mm Hg) 
200.degree. F. 
Specific Gravity (H.sub.2 O = 1) 
1.0 
Volatile Content (% by volume) 
3.0 
pH 7 
Appearance Milky white emulsion 
______________________________________ 
The non-ionic surfactant material, CONTROL SOLVE, is commonly used for 
spill abatement and control, particularly on solid surfaces such as 
concrete. The material is commercially available in either an aqueous 
concentrate, a premixed use solution, or in its non-aqueous form under the 
trade designations the encapsulation solution CONTROL SOLVE 114, CONTROL 
SOLVE 228, and CONTROL SOLVE 111, respectively. In the preferred 
embodiment of the present invention, premixed use solutions are employed. 
However, either aqueous concentrate or non-aqueous material can be 
successfully employed in the encapsulation solution of the present 
invention as a source of appropriate non-ionic surfactant material. 
When employed independent of anionic surfactant material, the concentration 
of non-ionic surfactant in the encapsulation solution is that amount 
sufficient to interact with the major portion of target chemical 
contaminants to dissociate these materials from the soil matrix and render 
them amenable to sequestration and/or decomposition. It is to be 
appreciated that the optimum concentration of non-ionic surfactant will 
vary depending upon the level of soil contamination encountered. The 
concentration of non-ionic surfactant will be that amount sufficient to 
economically treat the major portion of the targeted chemical 
contaminants. The term "major portion" as used herein is defined as that 
amount of a given chemical contaminant which when treated will yield a 
contaminant concentration level below a predetermined or set value. This 
value may be derived from experimental data or may be one set by 
regulatory agencies such as the United States Environmental Protection 
Agency. It is also possible to further reduce chemical contaminant 
concentrations to levels below the limits of detection possible with 
current analytical methods. Such reduction would be readily ascertainable 
given the disclosure of the present invention. 
While the concentration of non-ionic surfactant employed in the 
encapsulation solution of the present invention can be adjusted to treat 
various levels of chemical contaminant concentration, the non-ionic 
surfactant is generally present in an amount between about 2 and about 
25.0% by total composition volume, with amounts between about 2.0 and 
about 10.0% by volume being preferred. 
In the preferred embodiment, the non-ionic surfactant component is employed 
in combination with a sequestering agent such as an anionic surfactant. It 
has been found, quite unexpectedly, that when employed in combination, the 
anionic surfactant component provides enhanced sequestration properties 
while the non-ionic surfactant component actually interacts with the 
targeted chemical contaminants to break or weaken chemical bonds resulting 
in the ultimate conversion of the chemical contaminants to non-hazardous 
material. 
The sequestering agent component employed in the encapsulation solution is 
a compound or compound complex which is essentially insoluble in water but 
which can be readily dispersed therein. Additionally, the sequestering 
agent component is a compound or mixture of compounds which facilitates 
the ready dispersal of the non-ionic surfactant material and targeted 
chemical contaminants in water. In the preferred embodiment, the 
sequestering agent component is a combination of an anionic surfactant and 
an amphoteric surfactant. The anionic surfactant material of choice can be 
either a sulfate, ether sulfate, anionic sulfonate, phosphate ester, fatty 
acid carbocylate, sulfosuccinate, or anionic alkyl phenol ethoxylate with 
an anionic surfactant selected from the group consisting of sulfonates of 
ethoxylated linear alcohols, alkyl benzone sulfonates, alkyl sulfonates, 
alkyl aryl sulfonates, napthalene sulfonates, alpha olefin sulfonates and 
mixtures thereof being preferred. 
The sulfonates of ethoxylated linear alcohols which can be employed in the 
present invention have the general formula: 
EQU R--(OCH.sub.2 CH.sub.2).sub.x SO.sub.3 M 
wherein .mu. is an integer between 1 and about 5 and M is selected from the 
group consisting of alkali metal cations, amine cations, ammonium cations 
and mixtures thereof. Representative of the useful alkali metal cations 
are sodium, potassium, as well as mixtures thereof. 
The alkyl sulfonates which can be employed in the present invention include 
those having the general formula: 
EQU CH.sub.3 (CH.sub.2).sub.n SO.sub.3 M 
wherein n is an integer between about 6 and about 12 and M is selected from 
the group consisting of alkali metal cations, amine cations, ammonium 
cations and mixtures thereof. 
The alkyl aryl sulfonates which can be employed in the present invention 
include those having the general formula: 
##STR3## 
wherein n is an integer between about 6 and about 12 and M is an anion 
selected from the group consisting of alkali metal cations, amine cations, 
ammonium cations and mixtures thereof. 
The napthalene sulfonates which can be employed in the present invention 
have the general formula: 
##STR4## 
wherein R is a hydrocarbon radical having between 8 and 10 carbon atoms 
and M is an anion selected from the group consisting of alkali metal 
cations, amine cations, ammonium cations and mixtures thereof. 
Alpha-olefin sulfonates which can be employed in the present invention have 
the general formula: 
EQU RCH.dbd.CH--CH.sub.2 --SO.sub.3 M 
wherein M is selected from the group consisting of alkali metal cations, 
amine cations, ammonium cation or mixtures thereof and R is a hydrocarbon 
radical having between 9 and 15 carbon atoms. 
Alkyl benzene sulfonates are preferably employed as the anionic surfactant 
in the encapsulation solution of the present invention. Where alkyl 
benzene sulfonates are employed, they are, preferably, selected from the 
group consisting of alkyl benzene sulfonates having 8 to 14 carbon atoms 
in an essentially linear; i.e. unbranched alkyl chain being preferred. The 
amount of branching permissible in the alkyl side chain is to be 
determined by the degree of biodegradability desired in the anionic 
surfactant. As can be readily appreciated "soft" (biodegradable) material 
is preferred to "harder" compounds in this application as the aspect of 
biodegradability is important for any material in the encapsulation 
solution which may remain in the soil matrix after treatment. 
In the preferred embodiment, the alkyl benzene sulfonate may be defined as 
a linear alkylate sulfonate which is derived from the sulfonation of a 
blend of isomeric benzenes (primarily monoalkyl) with saturated side 
chains averaging 12 carbon atoms commonly known as detergent alkylate to 
form dodecyl benzene sulfonate. The sulfonate employed preferably is a 
cationic salt in which is selected from the group consisting of alkali 
metals, amine cations, ammonium cations and mixtures thereof. In 
practicing this invention, the preferred cation being an amine selected 
from the group consisting of isopropyl amine, trimethyl amine, t-buty 
amine, methyl amine, and mixtures thereof, with isopropyl amine being 
preferred. 
When the encapsulation solution contains a non-ionic surfactant component 
in combination with an anionic surfactant, the non-ionic surfactant is 
generally present in an amount between about 2.0 and about 95% by total 
composition volume, with amounts between about 2.0 and about 10.0% being 
preferred with amounts between about 2.0 and about 10% by volume being 
most preferred. The anionic surfactant component is present in an amount 
between about 2.0 and about 95.0% by total composition volume, with 
amounts between about 2.0 and about 40% being preferred. 
The sequestering agent component of the present invention can also contain 
an amphoteric surfactant material employed either in combination with or 
as a substitute for the anionic surfactant material. The amphoteric 
surfactant material can be either betaines, sultaines, glycinates, amino 
propionates, amphocarbocylates, or amphoteric sulfonates. In the preferred 
amphoteric surfactant material is selected from the group consisting of 
amphocarboxylate salts having between 2 and 12 carbon atoms in the 
carboxylate group, amphodicarboxylate salts having between 2 and 12 carbon 
atoms in the carboxylate group, amphoteric condensation products of 
carboxylic acids having 2 to 12 carbon atoms in each carboxylic acid 
group, betaines and mixtures thereof with sodium, potassium or ammonium 
salts being preferred. 
Amphocarboxylate salts suitable for use in the present invention are 
selected from the group consisting of cocoamphoacetate salts, 
cocoamphopropionate salts, stearoamphoacetate salts, 
capryloamphopropionate salts, butoxyethoxy acetate salts, and mixtures 
thereof, with an amphocarboxylate salt selected from the group consisting 
of p alkyldlimethyl betaines with alkyl groups having between 2 and 8 
carbon atoms being preferred. Suitable amphoteric condensation products of 
carboxylic acids for use in the present invention are selected from the 
group consisting of cocamphodiacetate salts, cocamphodipropionate salts, 
capryloamphodiacetate salts, capryloamphodipropionate salts, 
tallamphodipropionate salts, lavroamphodiacetate salts, organo-alkaloid 
complexes of plant-derived origin exhibiting high water solubility. The 
organo-alkaloid is selected from the group consisting of amino alkyl 
betaines having between 2 and 5 carbon atoms in the alkyl group. In the 
preferred embodiment, a betaine selected from the group consisting of 
cocamidopropyl betaine, amidoalkyl sultaines, amidoalkyl glycinates, and 
mixtures thereof is employed. 
Without being bound to any theory, it is believed that the presence of the 
amphoteric surfactant provides a complementary interaction with the 
non-ionic surfactant component which permits degradative interaction by 
the non-ionic surfactant on the target contaminant. In the encapsulation 
solution of the preferred embodiment, the amphoteric surfactant is present 
in an amount between about 2.0 and about 95.0% of the total composition 
volume with an amount between 2.0 and 40.0% being preferred when the 
amphoteric surfactant is employed in combination with an anionic 
surfactant. 
The sequestering agent component of the present invention can also include 
a surface active agent exhibiting cationic characteristics. Suitable 
cationic surfactants can include amine oxides, imadazoles, benzyl 
quaternerys and/or alkyl quaternerys. 
In preparing the encapsulation solution of the present invention an 
admixture of anionic surfactants and alkaloids can be formulated with 
additional non-ionic surfactants and additional water to prepare the 
composition of the present invention. A suitable anionic surfactant 
admixture is commercially available under the tradename DYNA-SOLVE from 
Allmond Laboratory Services of Albany, Ga. The material is a proprietary 
emulsion containing a naturally derived alkaloid amphoteric surfactant, an 
anionic surfactant and minor amounts of a non-ionic surfactant typically 
employed as petroleum dispersant and emulsifier having the characteristics 
outlined in Table II. 
TABLE II 
______________________________________ 
TYPICAL PROPERTIES OF DYNA-SOLVE 
______________________________________ 
Boiling Point 149.degree. C. 
Specific Gravity (H.sub.2 O = 1) 
1.02 at 25.degree./25 atm 
Volatile Content (% by volume) 
5% 
pH 6.0 to 8.0 
Appearance Clear amber viscous 
liquid 
______________________________________ 
The encapsulation solution of the present invention also can contain 
sufficient quantities of a suitable organic solvent to permit dispersion 
of the fluidizable matrix such as soil in the encapsulation solution and 
to improve the flow characteristics of matrix/encapsulation solution 
complex during processing. The organic solvent is, preferably, selected 
from the group consisting of butyl cellosolve, methyl cellosolve, 
ethylcellosolve, ethylene glycol monobutyl ethers and their derivatives 
and mixtures thereof in an amount between about 0.1% and 50.0% of the 
total encapsulation solution. In the preferred embodiment, butyl 
cellosolve in an amount between 1.0 and 30.0% is preferred. 
The concentration of non-ionic surfactant in the encapsulation solution of 
the preferred embodiment is that amount sufficient to interact with the 
major portion of target chemical contaminants to render these materials 
amenable to sequestration and/or decomposition. It is to be appreciated 
that the optimum concentration of non-ionic surfactant will vary depending 
upon the level of soil contamination encountered. The concentration of 
non-ionic surfactant will be that amount sufficient to economically treat 
the major portion of the targeted chemical contaminants. The term "major 
portion" as used herein is defined as that amount of a given chemical 
contaminant which when treated will yield a contaminant concentration 
level below a predetermined or set value. This value may be derived from 
experimental data or may be one set by regulatory agencies such as the 
United States Environmental Protection Agency. It is also possible to 
further reduce chemical contaminant concentrations to levels below the 
limits of detection possible with current analytical methods. In other 
words, chemical contaminants in the untreated soil matrix are present in 
the matrix at a first concentration level. The concentration of surfactant 
will be that amount sufficient to treat the targeted chemical 
contaminants, i.e. reduce the chemical contaminant concentration from the 
first concentration level to a second concentration level lower than the 
first level. Such reduction would be readily ascertainable given the 
disclosure of the present invention. 
While the concentration of non-ionic surfactant employed in the 
encapsulation solution of the present invention can be adjusted to treat 
various levels of chemical contaminant concentration, the non-ionic 
surfactant is generally present in an amount between about 2 and about 
25.0% by total composition volume, with amounts between about 2.0 and 
about 10.0% by volume being preferred. 
In order to ascertain a more specific concentration of non-ionic surfactant 
in the encapsulation solution of the present invention, attention is 
directed to the calibration steps of the present invention which are 
described in detail subsequently. 
The non-ionic surfactant is maintained in a suitable aqueous carrier 
medium. The aqueous carrier medium envisioned herein is water which is 
essentially free of organic and inorganic chemical contaminants which 
would interfere with the remediation process of the present invention. In 
the preferred embodiment, water which has been deionized and distilled by 
conventional procedures is sufficiently free of chemical contaminants for 
purposes of the present invention. 
The encapsulation solution of the present invention may be admixed in 
advance of application and stored in suitable vessels until needed. 
However, due to the variable nature of chemical contaminants in soil 
matrices, it is preferred that the encapsulation solution be prepared 
immediately prior to application with a non- ionic surfactant present in 
an amount which corresponds with the results obtained in the calibration 
step of the present invention. The calibration step will be described in 
greater detail subsequently. 
While it is anticipated that the encapsulation solution and the soil 
remediation method of the present invention can be efficaciously employed 
to treat and remove a variety of chemical contaminants, it is anticipated 
that the process of the present invention is most advantageously employed 
to remove and render harmless certain chemical compounds which for 
purposes of this discussion will be classified as hazardous as defined by 
the United States Environmental Protection Agency under subtitle C of the 
Resource Conservation and Recovery Act of 1976; i.e. having a flash point 
greater than 140.degree. F. More specifically, these materials include 
halogenated hydrocarbons as well as polyaromatic and monoaromatic 
hydrocarbons. As defined herein, the term "polyaromatic and monoaromatic 
hydrocarbon" is broadly defined as substituted and unsubstituted cyclical 
hydrocarbons having at least one napthenic or phenolic functionality 
associated therewith. Chemical contaminants which are specifically 
targeted for treatment by the process of the present invention include, 
but are not limited to organic compounds selected from the group 
consisting of polyhalogenated biphenyls, napthalene, acenapthalene, 
acenapthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, 
benz(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, 
benzo(a)pyrene, indeno (1,2,3-cd) pyrene, dibenz(a,h)anthracene, 
benzo(g,h,i)perylene, polychloronated biphenyls, polybiominated piphenyls 
and mixtures thereof. The term "halogenated hydrocarbon" as employed 
herein is defined as saturated or unsaturated branched or unbranched 
hydrocarbons having at least one halogen substituted thereon and having 
between two and 30 carbon atoms with two and 10 carbon atoms being 
preferred. The halogen group can be selected from the group consisting of 
fluorine, chlorine, iodine and mixtures thereof. Chemical contaminants 
which can be efficaciously treated by the method of the present invention 
employing the anionic/nonionic encapsulation solution include, but are not 
limited to organic compounds selected from the group consisting of 
chloronated hydrocarbons such as trichloroethylene, trichloroethane, 
tetrachloroethane, chloroform, methylene chloride, 1,1 dichloroethane, 1,3 
dichloropropane, dichlorobenzene; fluorocarbons such as 
chlorodifluoromethane, 1,1,2 tetrafluoroethane; chlorofluorocarbons such 
as dichlorodifluoromethane, and mixtures thereof. 
The process of the present invention is preferably a multistage method in 
which soil material to be treated is lifted from its original location by 
any conventional means such as a mechanical back hoe or the like and 
transported directly to the treatment device or to a suitable first stage 
pretreatment holding area where it can be directed into the treatment 
device as required. The soil to be treated can be any suitable soil, 
coarse sand, humus, clay-like or loam-like material. Optionally, prior to 
introduction into the treatment device, the soil material can be tilled or 
worked to break or shred large clods, if desired. 
The soil to be treated is introduced in a continuous manner into a suitable 
mixing device such as a pug milling apparatus where it can be brought into 
contact with encapsulation solution containing specific amounts of 
non-ionic surfactant necessary to treat the concentration of chemical 
contaminants found in that particular soil matrix. The total volume of 
encapsulation solution employed is that amount sufficient to saturate the 
soil volume to be treated. As used herein the term "saturation" is defined 
as the amount of encapsulation solution which must be added to a given 
soil volume to yield an excess or run-off amount of encapsulation solution 
between about 25% and about 50% of the total soil volume per hour after 20 
minutes of mixing. The material is mixed and macerated to ensure ultimate 
contact with the encapsulation solution. 
Without being bound to any theory, it is believed that saturation with 
encapsulation solution not only insures that sufficient amounts of the 
active ingredients in the encapsulation solution are delivered to the soil 
sample; saturation also provides intimate contact of the soil matrix to 
which the chemical contaminants adhere with sufficient encapsulation 
solution to permit the preferential bonding between the contaminant 
compounds and with the surfactant portion of the encapsulation solution. 
Finally, it is also believed that copious amounts of encapsulation 
solution assist in preventing the reattachment of the contaminant compound 
to the soil matrix as well as providing a suitable carrier medium for 
removal of at least a portion of the chemical contaminants which have 
become entrained in the encapsulation solution during processing. 
It is also believed that components in the anionic/nonionic encapsulation 
solution of the present invention interact and react with target chemical 
contaminants resulting in the breaking or severing of at least one 
chemical bond in the target chemical contaminant. This results in a 
reconfiguration of the chemical molecule rendering it more amenable to 
solubilization, and/or chemical breakdown to non-hazardous products or 
intermediary compounds which are amenable to action by biological agents, 
environmental forces or the like. 
The interval during which the encapsulation solution and the soil matrix 
being treated are mixed is one which is sufficient to facilitate 
encapsulation of a major portion of the targeted chemical contaminants to 
be treated and/or removed from the soil matrix. This interval can vary 
depending on the characteristics of the soil matrix to be treated, the 
concentration and type of contaminant present, and the overall removal 
effectiveness desired. In the preferred embodiment, mixing occurs for an 
interval sufficient to thoroughly saturate the soil matrix and form the 
slurry. In the preferred embodiment, mixing intervals between about 30 
seconds to about 10 minutes are anticipated; with mixing intervals between 
about 1 and about 5 minutes being preferred. 
Thorough mixture of the solution saturated soil is necessary to insure that 
intimate contact between the active encapsulation solution and all of the 
surfaces of the soil matrix has been achieved. Mixture can be accomplished 
by any of a variety of methods such as vibration, shredding, agitation and 
the like. The method of choice will preferably reduce the volume and 
number of any clumps or agglomerations of soil particles and help prevent 
their reformation during mixture. In the preferred embodiment, a 
macerative process is employed in which the soil-solution mixture is 
shearingly agitated by at least one suitably configured shearing blade. 
Admixture of the soil and encapsulation solution is most effectively 
accomplished by at least one pair of counter-rotating mixing blades and/or 
pug milling device which operate on the soil-solution mixture in the 
manner found in a pug milling process. Excess encapsulation solution can 
be removed from contact with the soil matrix after mixing is completed. 
This can occur immediately after mixing is completed or after a first 
contact interval of about 2 to 20 minutes, with a contact interval of 5 to 
10 minutes being preferred. The contact interval is that which is 
sufficient to permit reaction between a major portion of the chemical 
contaminants and the components of the encapsulation solution. 
In the process of the present invention, the initial contact interval 
terminates with the separation of the excess encapsulation solution from 
the soil matrix. Separation may occur at any time subsequent to mixing. In 
the preferred embodiment, separation occurs immediately prior to discharge 
from the mixing device. However, it is anticipated that the encapsulation 
solution may be removed in separate processing devices if desired. 
Separation and removal of excess encapsulation solution from the soil 
matrix can be accomplished by a variety of suitable methods which include, 
but are not limited to, staged evaporative processes and mechanical water 
separation techniques. 
Separation processes such as those envisioned for use in the process of the 
present invention need not remove the encapsulation solution in its 
entirety. In the preferred embodiment of the present invention a portion 
of the encapsulation solution is retained in the soil after it is returned 
to a second staging area on the treatment site. Once in place in the soil, 
the residual encapsulation solution continues to act on any contaminants 
bonded thereto rendering them susceptible to the decomposition action of 
aerobic and anaerobic bacteria present or specifically introduced into the 
soil. 
Without being bound to any theory, it is believed that the chemical process 
which takes place during the contact/mixing interval is one of 
bioencapsulation. Aromatic compounds such as the target chemical 
contaminants are attached to the soil matrix by some kind of relatively 
weak bonding force such as Vanderwall interaction. It is believed that 
this interaction most probably occurs between the aromatic portion of the 
chemical contaminant and the soil matrix. Plain water also exhibits a 
minor degree of affinity to the chemical contaminant materials. However, 
the interactive force between water and organic compound is so much weaker 
than that exhibited between the soil matrix and the aromatics that the 
quantity of organic compounds removed from the soil matrix by plain water 
does not appreciably lower the soil contaminant level. It is theorized 
that non-ionic and anionic surfactant materials such as those defined in 
the present invention, when added to water, increase the solution affinity 
of the resulting encapsulation material for organic compounds to a level 
which exceeds that exhibited between the aromatic and the soil matrix. 
It is also believed that the non-ionic surfactants employed herein have a 
hydrophobic portion which actively associates with the organic compounds 
contained on or in the soil matrix. The hydrophilic portion of the 
surfactant serves to solubilize the heretofore water insoluble aromatic 
material to the extent that the surfactant-organic complex can remain 
suspended in the aqueous medium for an interval sufficient to permit 
separation of the solution from contact with the soil matrix. Within the 
purview of this invention, suspension can be in the form of a true 
solution, an emulsion or a stable suspension. 
It has been unexpectedly discovered that aromatic compounds and halogenated 
hydrocarbons such as those defined herein are rendered susceptible to 
chemical decomposition when associated with non-ionic surfactants defined 
herein and encapsulated in the process of the present invention. Without 
being bound to any theory, it is believed that the bonding and 
encapsulation of the hydrocarbon contaminants which occur in the process 
of the present invention renders the compounds more susceptible to 
naturally occurring biochemical, mechanical and physical degradative 
processes such as would occur by microbial action, ultraviolet radiation, 
exposure to elevated temperature levels, fluctuations in ambient 
temperature and the like. It is believed that the interaction bonding 
process which is exhibited between the surfactant and the chemical 
contaminants is an affirmative biochemical encapsulation in which 
carbon-carbon bonds present in the chemical contaminant compound are 
abruptly broken thereby increasing the water solubility of the resulting 
molecule and rendering more susceptible to further breakdown. 
Thus, the process of the present invention provides a method whereby large 
quantities of chemical contaminants can be removed from the contaminated 
soil matrix through the introduction of encapsulation solution mixing and 
separation steps. The initial steps of the process of the present 
invention, provides reduction in chemical contaminant levels sufficient to 
stabilize the soil matrix against further contaminant leaching or 
migration. The residual encapsulation solution remaining in the soil 
matrix after processing is completed provides a material to which any 
residual contaminant can bond rendering the contaminant amenable to action 
by aerobic and anaerobic bacteria, present or purposely introduced into 
the soil matrix. 
The concentration of non-ionic and anionic surfactants as present in the 
encapsulation solution can be varied depending upon the contamination 
level and general condition of the soil matrix. In the preferred 
embodiment, concentration of the anionic surfactant and cellosolve diluent 
will vary in a one-to-one relationship with the non-ionic surfactant 
concentration. In order to determine the appropriate concentration of 
non-ionic surfactant in the encapsulation solution for a particular 
application, the process of the present invention preferably includes a 
calibration procedure to provide suitable analytical data on which to base 
calculations of the appropriate concentration range for the non-ionic 
surfactant in the encapsulation solution. In the calibration procedure of 
the process of the present invention at least one representative sample of 
the contaminated soil matrix is obtained. 
The representative soil sample may be obtained by any suitable, reliable 
reproducible method. In the preferred embodiment, a sample or series of 
samples are obtained by the method outlined in Michigan Public Act Number 
478 of 1988 as amended by Public Act Number 150 of 1989. These samples are 
analyzed by conventional methods to determine the area of greatest 
chemical contamination within the defined site. Suitable methods are 
defined in EPA Method 3540 and 8270. 
The exact weight of the samples tested can be any amount which will provide 
sufficient levels of extracted chemical contaminant for accurate analysis 
by any of a variety of known and accepted analytical procedures. Examples 
of these procedures include infrared analysis, gas chromatography, mass 
spectroscopy, gas chromatograph/mass spectroscopy and the like. In general 
relatively small samples sizes can be employed. In the preferred 
embodiment, sample sizes between about 5 and about 25 grams can be 
employed. 
Once the maximum contaminant concentration of the soil has been determined, 
the concentration of the encapsulation solution can be calibrated against 
this standard. To accomplish this, a calibration sample can be treated in 
a series of preliminary bench top runs to determine the effectiveness of 
the given concentration of the encapsulation solution. The calibration 
sample is washed with a test encapsulation solution having an initial 
concentration of non-ionic surfactant equal to [S]. 
The value [S] is graphically represented in FIG. 2. The value [S] is 
derived from the relationship between contaminant concentration in the 
soil matrix and the concentration of non-ionic surfactant necessary to 
obtain complete closure. The combined contaminant concentration is 
experimentally derived. In general, the concentration of non-ionic 
surfactant employed to obtain complete closure is that amount necessary to 
reduce the concentration of target chemical contamination below detection 
limits in 90% of the samples tested. 
Once the value [S] is determined, the efficacy of the initial non-ionic 
surfactant concentration value can be experimentally verified in the 
following manner. 
In the calibration procedure of the present invention, the initial 
calibration sample is washed with encapsulation solution containing a 
concentration of non-ionic surfactant equal to [S] while being 
mechanically agitated in a manner which ensures intimate contact between 
the washing encapsulation solution and the soil matrix. For bench scale 
operations, this agitation can be supplied by a rotary mixer. Mixing and 
contact continue for an interval which is sufficient to permit association 
of the chemical contaminants heretofore entrained in the soil matrix with 
the non-ionic surfactant and to approximate field conditions. In general 
the interval in which the calibration sample is saturated with 
encapsulation solution is between about 1 and about 20 minutes; with an 
interval between about 5 and about 10 minutes being preferred. 
The resulting encapsulation solution wash is then removed from contact with 
the soil sample by any suitable means such as rotary vacuum evaporation. 
The soil sample is then extracted with a suitable solvent in the manner 
described previously to preferentially extract any targeted chemical 
contaminants remaining on the soil matrix after treatment. 
The resulting extract is then prepared and analyzed by a suitable method as 
defined in accepted analytical literature to determine the effectiveness 
of the treatment method. If complete closure has been obtained i.e. the 
chemical contamination level has been reduced to an acceptable 
predetermined level; either that non-ionic surfactant concentration level 
can be employed as a standard to formulate an effective use solution or 
the non-ionic surfactant concentration can be literally reduced and tested 
on further calibration samples to obtain the optimum concentration level 
for use in the effective treatment level. 
Where unacceptable levels of contamination are still evident after initial 
treatment of the calibration sample, the level of non-ionic surfactant in 
the encapsulation is incrementally increased in relationship with the 
excess contaminant concentration to provide a modified encapsulation 
solution with a level of surfactant effective to treat the given soil 
matrix. While this iterative variation can occur in a hit or miss fashion, 
it has been found that it is most advantageous to interactively increase 
or decrease the concentration of non-ionic surfactant in increments 
between about 0.2 and about 1.0% by volume until an optimally effective 
encapsulation solution is obtained. In the preferred embodiment the 
increments are about 0.5 vol. % 
To further illustrate the process of the present invention, attention is 
directed to the following Examples. The Examples are included for 
illustrative purposes and are not to be construed as limitative of the 
present invention. 
EXAMPLE I 
In order to determine the initial level of chemical contaminant present in 
a soil matrix obtained from an industrial site in Western Michigan, a 
10.10 gram sample was extracted and analyzed for the presence of 
polynucleated aromatics following the procedures outlined in EPA Test 
Method 3540 and EPA Analytical Method 8270 using Methylene Chloride as the 
extraction solvent. The results are listed in Table III. 
EXAMPLE II 
A second sample of soil matrix weighing 10.2 grams was obtained from the 
Western Michigan Industrial site discussed in Example I. The sample was 
treated by the process of the present invention as outlined. 
An encapsulation solution as defined in the present invention was prepared 
by the admixture of 2 parts deionized water to 1 part CONTROL SOLVE 228 
commercially available from S&S Company of Georgia, Albany, Ga. to make 25 
ml of encapsulation solution having a non-ionic surfactant concentration 
of 2.0% by volume. The encapsulation solution was then admixed with the 
soil sample and agitated in a closed vessel by rapid shaking for an 
interval of two minutes. 
The encapsulation solution was, then, separated from the soil by vacuum 
filtration. The soil sample was, then, dried, by admixture with sodium 
sulfate in preparation for subsequent analytical procedures. The sample 
was, then, prepared by the process outlined in EPA Method 3540 and the 
resulting extract analyzed by the EPA method for analysis of aromatic 
hydrocarbons (EPA Method 8260: SW-846). The results are set forth in Table 
III. 
As can be seen by the results set forth, the procedure achieved significant 
reduction in the contaminant concentration in the soil matrix. 
EXAMPLE III 
A third sample of soil matrix weighing 10.2 grams was obtained from the 
Western Michigan Industrial site discussed in Example I. The sample was 
treated with an encapsulation solution prepared in the manner outlined in 
Example II to contain 2.5% by volume surfactant. The method of soil 
treatment is outlined in Example II. 
The results of the treatment were obtained by the analytical method 
outlined in Example II and are set forth in Table III. 
As can be seen from these results, effective closure has been obtained. 
EXAMPLE IV 
A 600 cubic yard sample of soil matrix weighing approximately 900 tons or 
914,442.3 kg is obtained from the Western Michigan Industrial site. The 
soil is continuously introduced into a Midland Mix-Trailer Pug Milling 
device Model Number T-4100, commercially available from Midland Asphalt 
Corporation of Victor, N.Y. at a rate sufficient to process the total 
sample in one hour. Encapsulation solution prepared as outlined in Example 
III is introduced into contact with the soil as it enters the mixing 
chamber. The amount of encapsulation solution introduced is sufficient to 
thoroughly saturate the soil sample (approximately 36,226 gallons). 
After a mixing interval of 1.5 minutes, the encapsulation solution is 
removed from the soil sample by mechanical screening. The processed soil 
is analyzed for target aromatic contaminants by routine EPA methods. No 
detectable levels of contaminants are found. 
TABLE III 
______________________________________ 
Chemical Contaminant Assay 
Concentration (ppb) 
Prior to After 1st After 2nd 
Compound Treatment Iteration Iteration 
______________________________________ 
Naphthalene 4003.1 404.2 BDL 
Acenaphthalene 
BDL BDL BDL 
Acenapthene BDL BDL BDL 
Fluorene 4974.5 BDL BDL 
Phenanthrene 6430.6 BDL BDL 
Anthracene BDL BDL BDL 
Fluoranthene 5854.3 BDL BDL 
Pyrene BDL BDL BDL 
Benz(a)anthracene 
BDL BDL BDL 
Chrysene BDL BDL BDL 
Benzo(b)fluoranthene 
BDL BDL BDL 
Benzo(k)fluoranthene 
BDL BDL BDL 
Benzo(a)pyrene 
BDL BDL BDL 
Indeno[1,2,3-c,d]pyrene 
BDL BDL BDL 
Dibenz(a,h)anthracene 
BDL BDL BDL 
Benzo(g,h,i)perylene 
BDL BDL BDL 
______________________________________ 
BDL Below Detection Limits (less than 330 ppb) 
EXAMPLE V 
In order to determine the initial level of chemical contaminants present in 
a soil matrix obtained from a second industrial site in Western Michigan 
in which the soil was contaminated with gasoline, a 10.2 gram sample was 
extracted and analyzed for the presence of polynucleated aromatics 
following the procedures outlined in EPA Test Method and EPA Analytical 
Method using methylene chloride as the extraction solvent. The results are 
listed in Table IV. 
EXAMPLE VI 
A second sample of soil matrix weighing 10.3 grams was obtained from the 
second industrial site discussed in Example V. The sample was treated by 
the process of the present invention as outlined. 
An encapsulation solution as defined in the present invention was prepared 
by the admixture of 2 parts deionized water to 1 part of an admixture 
containing 35% by volume isopropylamine dodecylbenzene sulfonate; 35% by 
volume cocamidopropyl betaine; 5% by volume branched nonyl phenoxypoly 
(ethyleneoxy) ethanol; 10% by volume butyl cellosolve and 15% by volume 
water to make 25 ml of encapsulation solution. The encapsulation solution 
was then admixed with the soil sample and agitated in a closed vessel by 
rapid shaking for an interval of two minutes. 
The encapsulation solution was, then, separated from the soil sample by 
vacuum filtration. The soil sample was, then, dried by admixture with 
sodium sulfate in preparation for subsequent analytical procedures. The 
sample was, then, prepared by the process outlined in EPA EPA-SW846-1118.1 
and the resulting extract analyzed for the presence of aromatic 
hydrocarbons (EPA Methods 8015; 8020; and 8210). The results are set forth 
in Table IV. 
As can be seen by the results set forth, the procedure achieved significant 
reduction in contaminant concentration in the soil matrix. 
TABLE IV 
______________________________________ 
CHEMICAL CONTAMINANT ASSAY 
CONCENTRATION 
.mu.g/kg Detection 
Prior to After Limit 
COMPOUND Treatment Treatment .mu.g/kg 
______________________________________ 
Benzene 13,450 25 10 
Toluene 26,420 47 10 
Ethylbenzene 
27,210 490 10 
Xylenes 117,930 640 10 
______________________________________ 
EXAMPLE VII 
In order to compare the effect of water washing and treatment with the 
anionic/non-ionic encapsulation solution on contaminated soil, a composite 
sample from the second industrial site discussed in Example V was 
obtained. Three samples were prepared for this composite. 
The first sample was analyzed according to the method outlined in EPA SW 
846:8020 for the presence and concentration of benzene, toluene, 
ethylbenzene and xylenes. The results are outlined in Table V. 
The second sample, weighing 10.1 grams, was washed with 25 ml deionized 
water according to the process outlined in Example VI. The wash water was 
separated from the soil sample by vacuum filtration. The soil sample was, 
then, dried by admixture with sodium sulfate and analyzed for the presence 
of chemical contaminants by the method outlined in SW-846:8020. The 
results are outlined in Table V. 
The third sample, weighing 10.2 grams was washed with 25 ml encapsulation 
solution prepared as in Example VI, in the manner outlined therein. After 
a two minute agitation interval, the encapsulation solution was separated 
from the soil sample by vacuum filtration. The sample was, then, prepared 
and analyzed in the manner outlined in Example VI. The results are 
outlined in Table V. 
As can be observed, treatment with the anionic/non-ionic surfactant 
encapsulation solution of the present invention significantly increased 
the total amount of organic contaminants removed from the soil matrix. 
TABLE V 
______________________________________ 
COMISON IN CONTAMINANT REDUCTION 
BETWEEN WATER WASH AND TREATMENT BY 
PROCESS OF PRESENT INVENTION 
WATER 
UNTREATED WASH TREATED 
CONTAMINANT .mu.g/kg .mu.g/kg .mu.g/kg 
______________________________________ 
Benzene 13450 8430 26 
Toluene 26420 16340 47 
Ethylbenzene 
27210 17950 490 
Xylenes 117930 NA 640 
______________________________________ 
EXAMPLE VIII 
The effectiveness of the method and composition outlined in Example VI in 
treating soil contaminated with polychlorinated biphenyls (PCB) was 
ascertained by treating three soil samples contaminated by oil containing 
PCB's in the manner outlined in Example VI. Initial and post-treatment PCB 
concentration was determined by the method outlined in SW-846:8080 
revised. The results are set forth in Table VI. As can be seen, all 
samples showed dramatic decrease in TPH and PCB concentration in treated 
soil. 
TABLE VI 
______________________________________ 
EFFECT OF TREATMENT ON SAMPLES 
CONTAINING PCB AND TPH 
FINAL 
INITIAL CONTAMINANT 
CONTAMINANT CON- 
CONCENTRATION CENTRATION 
SAMPLE (mg/KG) (mg/kg) 
NUMBER TPC PCB TPH PCB 
______________________________________ 
1 1486 73 12 0.52 
2 753 45 3 0.18 
3 248 19 2 0.11 
______________________________________ 
While the invention has been described in connection with what is presently 
considered to be the most practical and preferred embodiments, it is to be 
understood that the invention is not to be limited to the disclosed 
embodiments but, on the contrary, is intended to cover various 
modifications and equivalent arrangements included within the spirit and 
scope of the appended claims, which scope is to be accorded the broadest 
interpretation so as to encompass all such modifications and equivalent 
structures.