U.S. patent application number 11/801910 was filed with the patent office on 2007-09-20 for treating hazarous materials.
This patent application is currently assigned to Llyon Technologies, LLC. Invention is credited to Jack W. Matthews.
Application Number | 20070219404 11/801910 |
Document ID | / |
Family ID | 37235364 |
Filed Date | 2007-09-20 |
United States Patent
Application |
20070219404 |
Kind Code |
A1 |
Matthews; Jack W. |
September 20, 2007 |
Treating hazarous materials
Abstract
Methods of treating hazardous materials, such as, for example,
contaminated soils, are disclosed. In one aspect, a method may
include treating a contaminated soil with a hazardous material
treatment composition to form a resulting material. In one aspect,
the hazardous material treatment composition may include mostly
salt, and from 0.5 to 15 wt % sorbent. The method may further
include treating the resulting material with one or more inorganic
binding agents. Other methods of treating hazardous materials are
also disclosed, as well as compositions for treating hazardous
materials.
Inventors: |
Matthews; Jack W.; (Lone
Tree, CO) |
Correspondence
Address: |
BLAKELY SOKOLOFF TAYLOR & ZAFMAN
1279 OAKMEAD PARKWAY
SUNNYVALE
CA
94085-4040
US
|
Assignee: |
Llyon Technologies, LLC
|
Family ID: |
37235364 |
Appl. No.: |
11/801910 |
Filed: |
May 10, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11413985 |
Apr 28, 2006 |
|
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11801910 |
May 10, 2007 |
|
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60676062 |
Apr 29, 2005 |
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Current U.S.
Class: |
588/256 |
Current CPC
Class: |
B09B 3/0025 20130101;
B09C 1/08 20130101; B09C 1/02 20130101 |
Class at
Publication: |
588/256 |
International
Class: |
B09B 3/00 20060101
B09B003/00 |
Claims
1-17. (canceled)
18. A composition comprising: at least 75 wt % salt, the salt
including: monovalent cation halide salt; polyvalent cation halide
salt; sulfate salt; and magnesium salt; 0.5 to 15 wt % sorbent; and
a sufficient amount of base to give the composition a pH greater
than 10.
19. The composition of claim 18, further comprising: sodium
chloride present in highest concentration; an anti-corrosion agent;
from 1 to 5 wt % sorbent, wherein the sorbent comprises
zeolite.
20. The composition of claim 18, further comprising contaminated
soil and an inorganic binding agent mixed with the salt, the
sorbent, and the base.
Description
RELATED APPLICATIONS
[0001] The present application claims priority from and fully
incorporates herein, U.S. Provisional Patent Application No.
60/676,062 entitled "TREATING MATERIALS AND HAZARDOUS MATERIALS",
filed on Apr. 29, 2005. The U.S. Provisional Patent Application No.
60/676,062 is incorporated herein by reference.
BACKGROUND
[0002] 1. Field
[0003] Embodiments of the invention pertain to methods and
compositions for treating hazardous materials. In particular,
embodiments of the invention pertain to methods and compositions
for treating contaminated soils.
[0004] 2. Background Information
[0005] Tremendous volumes of soil worldwide are contaminated with
hazardous materials, such as, for example, oil-derived
hydrocarbons, and heavy metals, to name just a few examples. Soil
remediation is a process by which the soil may be treated in order
to reduce the level of hazardous materials in the soil. Large sums
of money are spent on soil remediation.
[0006] There are numerous approaches for remediating contaminated
soils. Representative approaches include, but are not limited to,
biological treatment to biologically alter the hazardous materials,
air stripping to strip the hazardous materials from the soil with
air, soil washing to wash the contaminants from the soil, solvent
extraction to extract the contaminants from the soil with a
solvent, vitrification in which the contaminates are locked into
the soil with vitrification, vacuum extraction in which a vacuum is
used to extract the contaminants from the soil, and thermal
desorption in which heat is used to thermally desorb the
contaminants from the soil. The approaches may be performed either
in-situ or else soil may be excavated and transported to a
treatment facility.
[0007] However, there are known disadvantages associated with each
of these approaches. For example, biological treatment may tend to
be relatively specific for certain contaminants and may face
challenges when mixed contaminants are present in the soil. Air
stripping and vacuum extraction may be relatively ineffective when
the contaminants have low volatility. Vitrification may tend to be
challenging when the soil has flammable materials and may tend to
be costly in operation and capital cost. Soil washing and solvent
extraction tend to consume large volumes of water or solvent which
then need to be processed and may tend to be expensive. Thermal
desorption may tend to be expensive and energy intensive.
[0008] Thus there is a general need in the art for new and useful
hazardous material treatment methods.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0009] The invention may best be understood by referring to the
following description and accompanying drawings that are used to
illustrate embodiments of the invention. In the drawings:
[0010] FIG. 1 conceptually illustrates a treated hazardous material
within a containment structure, according to one or more
embodiments of the invention.
[0011] FIG. 2 is a block diagram of a method of treating a
hazardous material, according to one or more embodiments of the
invention.
[0012] FIG. 3 is a block diagram of another method of treating a
hazardous material, according to one or more embodiments of the
invention.
DETAILED DESCRIPTION
[0013] Embodiments of the invention pertain to methods of treating
hazardous materials. Other embodiments of the invention pertain to
compositions to treat the hazardous materials. Further embodiments
of the invention pertain to methods of making the compositions or
methods of using the compositions. Yet further embodiments of the
invention pertain to shaped products formed using the compositions
and/or the methods.
[0014] In the following description, numerous specific details are
set forth. However, it is understood that embodiments of the
invention may be practiced without these specific details. In other
instances, well-known structures and techniques have not been shown
in detail in order not to obscure the understanding of this
description.
I. Example Hazardous Material Containment Structure Having Multiple
Different Mechanisms for Containment
[0015] FIG. 1 conceptually illustrates a treated hazardous material
100, such as, for example, a heavy metal, organic contaminant, or
the like, within a containment structure 110, 120, 130, according
to one or more embodiments of the invention. The containment
structure includes a zeolite (or other sorbent) 110, a salt
crystal/soil matrix 120, and a cement (or other inorganic binding
agent or hardening material) 130. A potential advantage of the
multi-layered containment structure is that hazardous material may
be sealed in the zeolite or other sorbent and contained by multiple
different layers and mechanisms of containment.
[0016] The zeolite or sorbent may provide a first mechanism and
material of containment for the hazardous material. The hazardous
material may be selectively drawn into or sorbed and chemically
held or retained in cavities or pores of the internal structure of
the zeolite or other sorbent. Chemical bonds or interactions may be
used to hold the ions or molecules within the zeolites or other
sorbents. By way of example, heavy metal cations and other ions may
be coordinated within the zeolite by an ion exchange process and
held by ionic chemical forces.
[0017] The salt/crystal/soil matrix may provide a second layered
mechanism and material of containment of the hazardous material.
The zeolite or other sorbent may be coated or surrounded, at least
partially, by a portion of the salt crystal/soil matrix. In the
matrix, the crystals may be bonded with surfaces of the soil. The
salt crystals may also be formed in and may tend to close off or
block the pores or other openings of the zeolite or other sorbent.
The salt crystal/soil within the pores may tend to be relatively
dense and impenetrable by the hazardous material and may tend to
close or seal the hazardous material therein. In some cases
remaining ions or other hazardous material may be incorporated
directly into the salt crystals, which may further help to
immobilize and contain the hazardous material.
[0018] The cement or other inorganic binding agent or hardening
material may provide a third outer mechanism and material layer of
containment of the hazardous material. The cement may tend to coat,
surround, and/or encapsulate the crystal/soil matrix. The cement
may tend to fill in gaps in the crystal/soil matrix, and may tend
to be formed in and close off remaining pores or other openings of
the zeolite or other sorbent. This may further tend to close and
seal the hazardous material within the cement. In some cases
remaining ions or other hazardous material may be incorporated
directly into the hardened cement by cementitious reactions, which
may further help to immobilize and contain the hazardous
material.
[0019] The use of a layered containment structure including
multiple different material layers and mechanisms of containment
may help to immobilize and contain the hazardous material. This may
help to reduce leaching, migration, and other movement of the
hazardous material.
[0020] A conceptual illustration of the sequential or layered
containment process and result for a single sorbent particle have
been used for purposes of illustration. It is to be appreciated
that when dealing with real materials and processes, perfect
layering may not necessarily always be achieved. In addition, such
layering may be formed around clumps or other groups of particles,
rather than a single sorbent particle.
II. Example Method for Treating Hazardous Materials
[0021] FIG. 2 is a block diagram of a method 200 of treating a
hazardous material, according to one or more embodiments of the
invention. The method includes treating the hazardous material with
a composition including a sorbent and a salt, at block 210. The
sorbent may sorb at least a portion of the hazardous material, and
the salt may crystallize around the sorbent to help encapsulate the
hazardous material within the sorbent and/or the containment
structure.
[0022] Then, the resulting treated hazardous material may be
treated with an inorganic binding agent or hardening agent, such
as, for example, cement, lime, tricalcium silicate, or other
cementitious material, or combination thereof, at block 220. The
hardening material or binding material may harden around the
sorbent and salt crystals and further help to encapsulate or seal
the hazardous material within the sorbent and/or the containment
structure.
III. Another Example Method for Treating Hazardous Materials
[0023] FIG. 3 is a block diagram of another method 300 of treating
a hazardous material, according to one or more embodiments of the
invention. Examples of suitable hazardous materials that may be
treated include, but are not limited to, contaminated soils, and
industrial wastes or by-products or effluents. For purposes of
illustration, the aforementioned method will be discussed largely
in the context of treating contaminated soil, although the scope of
the invention is not so limited.
A. Preparation of Treatment Composition and Soil
[0024] Shortly prior to use, such as, for example, from several
minutes to several hours before use, a hazardous material treatment
composition as disclosed elsewhere herein, may be combined with
water, to form a thick solid-liquid sludge, "mud", or slurry, at
block 310. The water of the slurry may be saturated or
supersaturated with at least some of the salts of the hazardous
material treatment composition. Alternatively, water may be added
to the soil, or to the mixture of the soil and the treatment
composition.
[0025] Contaminated soil may be shoveled, augered, mined,
bulldozed, or otherwise removed from the contaminated site. By way
of example, the soils or other materials may be contaminated with
hazardous materials including, but not limited to, hydrocarbons
(for example petroleum, petroleum derivatives, jet fuel, tars,
gasoline, kerosene), halogenated hydrocarbons (for example
tetrachloroethylene), polychlorinated biphenyls, poly-aromatic
hydrocarbons, pesticides, other organic pollutants, heavy metals
(lead, cadmium, mercury, etc.), other contaminants, and
combinations thereof. If appropriate, the contaminated soil may
optionally be introduced into the mixer and homogenized prior to
treatment, although this is not required.
B. Mixing Hazardous Material with Treatment Composition and
Water
[0026] Then, the sludge may be contacted with the contaminated soil
and used to treat the contaminated soil. In one or more embodiments
of the invention, the hazardous treatment composition and
contaminated soil may be combined in a volume ratio that ranges
from about 1:50 to 1:2, although the scope of the invention is not
limited to these particular ratios. In one aspect, the composition
added may provide an amount of zeolite that is sufficient to sorb
the intended amount of the contaminant.
[0027] Referring again to FIG. 3, the hazardous material, the
hazardous material treatment composition, and the water may be
contacted and mixed, at block 320. In one or more embodiments of
the invention, proper proportions of the contaminated soil and
sludge may be introduced into and mixed in a mixer.
[0028] In one or more embodiments of the invention, the mixer may
include a plough mixer, although this is not required. Non-limiting
examples of a suitable plough mixers are the L-20, KM-1200, or
KM-2000 ploughshare.RTM. mixers, which are commercially available
from Lodige USA, Inc, of Ronkonkoma, N.Y., having the parent
company of Warburg, Germany. The ploughshare.RTM. mixers may mix
the components by utilizing a mechanically induced fluidized bed
reportedly created by shovels that rotate close to inner walls of a
drum and thrust the components inside the drum. In one or more
embodiments of the invention, such mixers may be operated at from
about 50 to 300 revolutions per minute (rpm) to achieve a Froude
Number ranging from about 6 to 8, such as from 6 to 7, although
this is not required.
[0029] In one or more embodiments of the invention, the
contaminated soil and treatment composition may be mixed under such
conditions for a period of time that is less than about 10 minutes,
or less than about 7 minutes, such as, for example, from about 2 to
7 minutes. Often, the period of time is from about 3 to 6 minutes,
and may be less than 5 minutes.
[0030] A potential advantage of using such plough mixers is that
they may achieve comparatively good mixing of the contents of the
drum in a relatively short period of time, which may tend to be
compatible with the treatment processes described herein. The
mixing action may also help to avoid separation of the salt
crystals from around the zeolites. However, the scope of the
invention is not limited to just these types of mixers. Other types
of mixers may also optionally be used. For example, Hobart dough
mixers have been tested and found to be suitable. In one aspect,
the mixer may optionally be provided on a mobile platform, such as,
for example, a bed of a vehicle, or a trailer, and moved to a
remediation site and used there, although this is not required.
[0031] In one or more embodiments of the invention, the temperature
in the mixer during the mixing process may be controlled to be in
the range of about 80 to 120.degree. F., although this is not
required. Some of the heat may be provided by exothermic processes
and additional heating and/or cooling may also optionally be
used.
[0032] In one or more embodiments of the invention, the amount of
water in the mixer during this stage of mixing may be adjusted or
prescribed to be in the range of 10 to 20 wt %, such as, for
example, from 12 to 16 wt %. A deflocculant such as sodium silicate
may optionally be included and may allow reduction in water
content, if desired. However, the scope of the invention is not
limited in this respect.
C. Sorbing Hazardous Material with Sorent
[0033] Referring again to FIG. 3, during the mixing period, and
potentially shortly thereafter, the zeolites or other sorbents of
the treatment composition may sorb at least a portion of the
hazardous materials of the soil, at block 330. The zeolites or
other sorbents may provide an environment that may sorb and retain
or hold the hazardous materials. In one or more embodiments of the
invention, the zeolites of the treatment composition may initially
be dehydrated or dried so that they may sorb more water potentially
laden with contaminants into their pores, although this is not
required. In one or more embodiments of the invention, the zeolites
may be pre-treated to promote binding or retention of the hazardous
materials, although this is not required. As one example, a
surfactant, such as, for example, hexadecyltrimethylammonium
bromide, may be used to treat the zeolite to make the internal
cavities of the zeolite affinitive for anions instead of cations.
Treated and non-treated zeolites may be used for both cations and
anions. As another example, a chlorine compound, such as, for
example, a perchlorinate, may be used to create a stationary
solvent phase in the cavities to customize sorption for organics.
As another example, a small molecular or ion trap may be included
in the zeolites. As yet another example, sodium hydroxide may be
used to open up the internal structure, such as to facilitate
sorption of larger molecules.
D. Growing Salt Crystals Around Sorbent
[0034] During the mixing period or process, salt of the treatment
composition may start to form crystals that may grow in, on, and
around, and coat particles, agglomerates, or other portions of the
zeolites and soil, at block 340. Some of the salt materials may
react with the surfaces of the soil and zeolites to provide good
contact and adhesion and the salt materials may grow as crystals
between the soil and zeolites. The salts may become occluded into
the growing matrix as anion and cation donors. Water having the
salts therein may be drawn or sorbed into the pores of the zeolites
and thereafter crystals may form in the pores or internal structure
to help seal the hazardous materials in the zeolites. This may
result in an aggregate in which the crystals bound to the soil and
zeolites form a coating, sheath, or encapsulation layer to help
encapsulate the hazardous materials within the cavities of the
zeolite. This may tend to reduce leaching or removal of the
hazardous materials from the cavities of the zeolites. In some
cases, ionic hazardous materials may potentially be incorporated
directly in the salt crystals by salt crystal formation reactions
or by the salt crystals growing around them, which may further help
to contain these materials.
[0035] It is presently thought that excessive mixing may
potentially tend to reduce the effectiveness of the containment of
the hazardous materials. Without wishing to be bound by this
particular theory, one potential explanation is that the chloride
salts and other salts may be over mixed or "emulsified" with the
soil, which may tend to hinder crystal growth and/or encapsulation
of the hazardous materials within the cavities of the zeolites.
Another potential explanation is that excessive mixing may
potentially break the salt crystals free of the zeolites.
E. Mixing Cement with Sorbent and Salt Crystal Mixture
[0036] Referring again to FIG. 3, after mixing the hazardous
materials with the hazardous material treatment composition as
described above, the resulting mixture or treated product may
optionally be further treated with cement or another inorganic
binding agent. The cement or other inorganic binding agent may be
mixed with the aforementioned resulting mixture, at block 350.
[0037] In various embodiments of the invention, the cement may be
mixed in an amount that is from about 0.5 to 10 wt %, from about
0.5 to 5 wt %, or from about 1 to 3 wt % of the total volume of
hazardous material treated, although the scope of the invention is
not so limited. More cement may also optionally be used, although
this may tend to increase the cost of treatment. The mixing may
coat or otherwise provide the cement or other inorganic binding
agent or composition around particles, clumps, or other portions of
the zeolite, and growing and/or grown crystals.
[0038] In one or more embodiments of the invention, the inorganic
binding agent may be introduced into the same mixer that already
contains the mixture previously described. Alternatively, a
different mixer may be used. In one aspect, a first mixer to mix in
the treatment composition and a second mixer to mix in the lime
and/or cement may be connected in series with one another to
provide a continuous mixing process, which may potentially help to
reduce downtime needed to load and unload mixers.
[0039] In one or more embodiments of the invention, the cement
and/or lime may be mixed with the treated hazardous material
mixture for a period of time ranging from about 30 seconds to 3
minutes, although this is not required. In aspects, the period of
time may be less than 2 minutes, or less than 1 minute, although
this is not required. It is presently thought that excessive mixing
may tend to disrupt the encapsulation or containment structure.
[0040] When adding the cement, or during the mixing period, the
water content in the mixer may optionally be adjusted to a value
that is appropriate to promote formation of good hardened monolith.
For example, in one or more embodiments of the invention, an
adjustment amount of water may be added to give final water content
is in the range of from about 14 to 18 wt %. A deflocculaant such
as sodium silicate may optionally be used to reduce amount of water
or otherwise.
F. Hardening the Binding Agent Around Sorbent and Salt Crystals
[0041] Referring again to FIG. 3, the cement or other binding agent
may harden, at block 360. As it hardens, the cement may provide a
hard coating, sheath, or encapsulation layer around the particles,
clumps, or other portions of the zeolite, and growing and/or grown
crystals, which may further help to reduce leaching or other escape
of the hazardous material from the internal structures of the
zeolites. The cement or other inorganic binding agent may also
contribute solidity, mechanical integrity, and/or strength to the
treated material. In some cases, heavy metals, ions, or other
hazardous materials may be incorporated directly in the cement
potentially by cementitious reactions, which may further help to
contain these materials.
G. Example Optional Variations of the Described Method
[0042] Various exemplary hazardous material treatment methods have
been described in conjunction with FIG. 3, although the scope of
the invention is not limited to just these particular methods.
Alternate methods are contemplated in which operations are
performed in different order. For example, water may be combined
after commencement of mixing of the hazardous material treatment
composition and the hazardous material. As another example, water
may first be combined with the soil instead of the treatment
composition. Still alternate methods are contemplated in which
operations are added to the methods. For example, the unhardened
cementitious mixture may be shaped or molded. As another example,
soil analysis may be performed and a treatment composition may be
tailored based on the soil analysis. Many further modifications and
adaptations may be made to the methods and are contemplated.
IV. Exemplary Uses of the Treated Hazardous Materials
A. Soil Stabilization
[0043] One or more building codes, such as, for example, one or
more regional building codes and/or the Universal Building Code,
may govern the building of structures on a particular soil or land.
These codes may specify in part minimum compressive strength to
support buildings thereon. If the native compressive strength of
the soil or land is insufficient or too low, soil conditioning may
be performed to increase the compressive strength, so that building
on the soil or land may be permitted.
[0044] By way of example, a real estate developer or other entity
may desire to build one or more buildings on land that is
contaminated with a hazardous material, such as, for example,
petroleum products, pesticides, mine tailings, or the like. Soil
from the land may be sampled and tested for compressive strength.
In some cases, the compressive strength of the native soil or land
may also be lower than that required by one or more building codes
in order for buildings or other structures to be constructed on the
land.
[0045] In accordance with one or more embodiments of the invention,
the hazardous material contaminating the land may be treated as
disclosed elsewhere herein. In addition, in accordance with one or
more embodiments of the invention, the resulting treated hazardous
material may be returned to the land and used for soil conditioning
and/or to increase the compressive strength of the soil or land
upon which one or more buildings are to be constructed or otherwise
provided. A method, according to one or more embodiments of the
invention, may include returning treated contaminated soil
including cement or other inorganic binding agent back to the site
to replace the contaminated soil that was removed in order to
increase the compressive strength of the resulting soil or
land.
[0046] In one or more embodiments of the invention, the
contaminated soil may be treated with an amount of cement or other
inorganic binding agent that is sufficient to mechanically
stabilize the soil concurrent with the remediation. A greater
amount of cement or other inorganic binding agent generally
provides a greater increase in the compression strength of the
soil. For example, in one or more embodiments of the invention, an
amount of cement or other inorganic binding agent to be used for
treatment that would result in at least a specified, regulated, or
otherwise predetermined compressive strength may be estimated,
calculated, empirically measured, or otherwise determined based, at
least in part, on one or more, or both of, a measured native
compressive strength of the soil and/or one or more predetermined
compressive strengths specified by one or more building codes.
B. Forming Useful Shaped Objects or Products
[0047] In one or more embodiments of the invention, after mixing in
the cement, lime, or other inorganic binding agent, but prior to
hardening, the mixture including the unhardened cement or other
inorganic binding agent may be molded or otherwise shaped and then
hardened to form one or more useful molded or shaped objects or
products. Examples of suitable useful molded or shaped objects or
products include, but are not limited to, jersey barriers, sidewalk
panels, bricks, cement pipes, housing siding, other building and
construction materials, and other objects that will be apparent to
those skilled in the art and having the benefit of the present
disclosure. Advantageously, building or construction materials may
be formed on-site from on-site materials instead of having to be
hauled in. In one or more embodiments of the invention, a solid
material with a lower density than water, such as, for example,
Styrofoam, other plastics, wood, or the like, may be used as a
filler, in order to form a boat dock or other structure that may
float. Alternatively, the material may be used for road base or the
like. Advantageously, a contaminated soil or other contaminated
material may be converted into a useful object or objects that may
have some value and potential for use and/or resale.
V. Example Hazardous Material Treatment Compositions
[0048] As described above, in one or more embodiments of the
invention, a hazardous material, such as, for example, contaminated
soil and industrial effluents or by-products, may be treated with a
hazardous material treatment composition containing salt and
sorbent. A hazardous material treatment composition, according to
one or more embodiments of the invention, may include in relatively
larger proportion or mostly a salt mixture and in relatively
smaller proportion one or more sorbents to sorb one or more
hazardous materials. As used herein, mostly salt means more than
50% salt. By way of example, in one or more embodiments of the
invention, the hazardous material treatment composition may include
at least 75 wt % salt, such as, for example, from about 75 to 99.5
wt % salt, and at least 0.5 wt % sorbent, such as, for example,
from 0.5 to 25 wt % sorbent, although the scope of the invention is
not so limited.
[0049] The inventor has considered numerous different possible
treatment compositions, including compositions with varying amounts
of various different types of salts, and different types of
sorbents. This section describes various embodiments of hazardous
material treatment compositions that may be used. However, the
scope of the invention is not limited to these particular treatment
compositions. Many further modifications and variations of these
treatment compositions are contemplated and will be apparent to
those skilled in the art and having the benefit of the present
disclosure.
[0050] A suitable salt mixture, according to one or more
embodiments of the invention, may optionally include one or more
halide salts, such as, for example, one or more chloride salts,
together with one or more sulfate salts, although this is not
required. The inclusion of both sulfate and halide salts may allow
encapsulating the zeolites within a matrix of different crystals
formed integrally with one another which may tend to improve
encapsulation. The halide and sulfate salts may crystallize to form
different crystal structures that may interlock and thereby help to
contain hazardous materials within a matrix. The sulfate salts may
tend to promote formation of monoclinic crystals and other
different crystal shapes, which may tend to add integrity to the
salt crystals and promote good encapsulation. One particular
example of a suitable sulfate salt is magnesium sulfate, although
others are also suitable. Chloride salts tend to promote good and
rapid crystal growth. In one or more embodiments of the invention,
the one or more halide salts may optionally include one or more
monovalent cation salts, and one or more polyvalent cation salts,
although this is not required. Suitable monovalent halide salts
include, but are not limited to, sodium chloride, ammonium
chloride, potassium chloride, and the like. Suitable polyvalent
halide salts include, but are not limited to, calcium chloride,
magnesium chloride, magnesium fluoride, and the like. In one
aspect, this may create different crystal structures that may add
diversity and interlock to aid containment. This may further
promote containment of the hazardous materials within the confines
of a matrix of inter-grown crystals and potentially help to reduce
leaching of hazardous materials.
[0051] One type of suitable sorbent is a zeolite. A zeolite may
include a natural or synthetic hydrous silicate or aluminosilicate
microporous solid that may have a highly organized or structured
open three-dimensional crystal structure of openings and cavities
in a lattice. The zeolite may act as a molecular sieve, adsorbent,
and/or ion exchanger to selectively sorb molecules and/or ions of
suitable size into the internal structure based, at least in part,
on a size exclusion process and/or the chemical environment inside
the cavities. Other suitable sorbents include, but are not limited
to, chelating agents, and other materials known to have binding or
bonding properties with respect to known types of hazardous
materials. Calcined clays, activated carbons, and like sorbents may
also potentially be used in some embodiments depending upon the
particular hazardous material and implementation. For example,
bentonite, illite and kaolin (all potentially calcined) may
potentially be used, depending upon the particular implementation.
Bentonite, illite and kaolin are also alumino-silicates.
Combinations of different types of sorbents may optionally be
included in the composition, such as, for example, to each sorb
different types of hazardous materials. The total sorbent included
in the composition may be based, at least in part, on the amount of
hazardous material to be sorbed. In various embodiments of the
invention, the total sorbent may be less than 15 wt %, less than 10
wt %, less than 5 wt %, and/or more than 0.5 wt %, although this is
not required.
[0052] Other components may optionally be included in the hazardous
material treatment composition. For example, magnesium may
optionally be included in order to help react with soil, or the
like to help promote strong and integral attachment of the crystals
to the soil, although this is not required. A relatively higher
soluble form of magnesium, such as, for example, magnesium oxide,
may optionally be included to increase the amount of soluble
magnesium when the composition is combined with water.
[0053] As another example, the composition may optionally include
one or more pH adjustment chemicals, such as, for example, sodium
bicarbonate, sodium carbonate, potash, or another base, or a
combination of bases, to promote a basic pH, although this is not
required. A basic pH, such as, for example, a pH greater than 10,
or greater than 11, or greater than 12, may potentially help to
avoid build up of hydrogen gas during storage. The high pH may also
help to protect against unexpected exposure to acid.
[0054] As yet another example, the composition may optionally
include one or more anti-corrosion chemicals or salts, such as, for
example, aluminum chloride, although this is not required. The
aluminum chloride may help to reduce corrosion of steel and certain
other metals. Aluminum chloride may be included in various
proportions in the composition depending upon whether or not the
potential for corrosion is of concern.
[0055] As a still further example, an indicator chemical or
material may optionally be included in the composition to provide
an aid for visually or otherwise assessing the degree of mixing of
the mixture or the homogeneity, although this is not required.
Suitable indictor chemicals or materials include, but are not
limited to, potassium permanganate, dyes, ferromagnetic particles,
or other materials whose relative concentration in the mixture may
readily be assessed. These are just a few examples.
VI. Specific Examples of Suitable Hazardous Material Treatment
Compositions
[0056] An example of a suitable hazardous material treatment
composition, according to one or more embodiments of the invention,
is disclosed in Table 1. Components and concentrations are listed.
TABLE-US-00001 TABLE 1 Component Concentration (wt %) Salt 75-99.5%
Sorbent 0.05-25%
[0057] Another example of a suitable hazardous material treatment
composition, according to one or more embodiments of the invention,
is disclosed in Table 2. Components and concentrations are listed.
TABLE-US-00002 TABLE 2 Component Concentration (wt %) Monovalent
Halide Salt Remainder Polyvalent Halide Salt 0-35% Sulfate Salt
0-5% Anti-Corrosion Agent 0-5% Magnesium Oxide 0-5% Base Sufficient
to give pH >10 Sorbent 0.5-25%
[0058] In various embodiments of the invention, from all to a small
amount of one or more, or various combinations, of the polyvalent
halide salt, the sulfate salt, the anti-corrosion agent, and
magnesium oxide, may optionally be omitted from the composition.
The remaining percentage or bulk of the mixture may be made up of a
monovalent halide salt, such as, for example, sodium chloride,
which is widely available and relatively inexpensive.
[0059] Yet another example of a suitable hazardous material
treatment composition, according to one or more embodiments of the
invention, is disclosed in Table 3. Components, concentrations, and
optional particle sizes are listed. TABLE-US-00003 TABLE 3
Component Concentration (wt %) Particle Size Sodium Chloride
Remainder 0-1 mm Ammonium Chloride 0-2% or about 1% 0-1 mm Aluminum
Chloride 0-5% or about 3% 0-1 mm Potassium Chloride 0-20% or about
15% 0-1 mm or flocks Calcium Chloride 0-20% or about 15% 0-5 mm
Magnesium Chloride 0-20% or about 15% fine grain or 50 mesh
Magnesium Oxide 0-4% or about 2% -200 mesh Magnesium Sulfate 0-4%
or about 3% 0-1 mm Sodium Carbonate 0-4% or about 3% 0-1 mm Zeolite
(ASM A4) 1-10% or about 2-6% -325 mesh Potassium Permanganate 0-2%
or about 0-1% 0-1 mm
[0060] In various embodiments of the invention, from all to a small
amount of one or more, or various combinations, of ammonium
chloride, aluminum chloride, potassium chloride, calcium chloride,
magnesium chloride, magnesium oxide, magnesium sulfate, sodium
bicarbonate, and potassium permanganate, may optionally be omitted
from the composition. The remaining percentage or bulk of the
mixture may be made up of sodium chloride.
[0061] A still further example of a suitable hazardous material
treatment composition, according to one or more embodiments of the
invention, is disclosed in Table 4. Components, concentrations, and
optional particle sizes are listed. In this composition, the term
"about" means .+-.50% of the indicated amount for indicated amounts
that are less than 5% and .+-.20% of the indicated amount for
indicated amounts that are over 5%. In this composition, the
remaining percentage or bulk of the mixture may be made up of
sodium chloride. Sodium chloride may be present in the highest
concentration. TABLE-US-00004 TABLE 4 Component Concentration (wt
%) Particle Size Sodium Chloride about 35% 0-1 mm Ammonium Chloride
about 1% 0-1 mm Aluminum Chloride about 3% 0-1 mm Potassium
Chloride about 15% 0-1 mm or flocks Calcium Chloride about 15% 0-5
mm Magnesium Chloride about 15% fine grain or 50 mesh Magnesium
Oxide about 2% -200 mesh Magnesium Sulfate about 3% 0-1 mm Sodium
Carbonate about 3% 0-1 mm Zeolite (ASM A4) about 1-5% -325 mesh
Potassium Permanganate about 0-1% 0-1 mm
[0062] Many other variations of the compositions included in Tables
1-4 are contemplated and will be apparent to those skilled in the
art and having the benefit of the present disclosure. For example,
compositions are contemplated that include additional components,
omit one or more of the listed components, and/or have the
components in different proportions. The scope of the invention is
not limited to any known composition.
[0063] Compositions like those shown above, or variations of these
compositions, may include solid particulate materials or powders
that may be mixed or otherwise combined together in the indicated
proportions. The resulting mixtures may optionally be sealed in a
container or otherwise packaged and optionally stored until an
intended time of use.
VII. Optionally Tailoring Hazardous Material Treatment Compositions
to Particular Hazardous Materials
[0064] The hazardous material treatment compositions disclosed
above are suitable for treating a wide variety of contaminated
soils. However, in one or more embodiments of the invention, a
hazardous material treatment composition may optionally be altered
and/or tailored for a particular contaminated soil based, at least
in part, on analysis of soil and contaminant properties. Initially,
a contaminated soil sample may be collected and analyzed. By way of
example, the soil may be analyzed for water content, organic
content, hazardous material type, hazardous material content,
electrical conductivity, compressive strength, pH, salt content,
and optionally other parameters. The hazardous material treatment
composition may be formed or modified based at least in part on the
analysis. By way of example, the type of zeolite or other sorbent
may be determined based on the type of hazardous material, the
amount of zeolite or other sorbent may be determined based on the
amount of hazardous material, the amount of water needed for
addition to the hazardous material treatment composition may be
determined based on the amount of water in the soil, the amount of
cement to add may potentially be based in part on the compressive
strength, and/or the amount of salt in the composition may
potentially be based on the amount of salt in the soil. Such
adaptations may potentially improve treatment, but are not
required. Leaching tests may also optionally be formed on treated
samples prior to large-scale remediation treatment. However, such
tailoring of the treatment composition is optional and not
required. Pre-packaged general-purpose treatment compositions may
also optionally be used.
VIII. Examples
[0065] Having been generally described, the following examples are
given as particular embodiments of the invention, to illustrate
some of the properties and demonstrate the practical advantages
thereof, and to allow one skilled in the art to utilize the
invention. It is understood that these examples are to be construed
as merely illustrative.
EXAMPLE 1
[0066] Experiments have been performed to demonstrate that
treatment as disclosed herein may significantly increase the
compressive strength of soil. A sample of soil was treated with a
hazardous material treatment composition similar to that shown in
Table 4. The volume ratio of soil to treatment composition was on
the order of 1:10. About 2.5 wt % Portland cement was used. The
compressive strength measurements were made using ASTM C-39. The
results indicated that the compressive strength of the treated soil
increased over time. After several days, the compressive strength
of the treated soil was generally found to be greater than about 80
psi, which is significantly greater than the compressive strength
of the original soil before treatment.
EXAMPLE 2
[0067] This example demonstrates the effectiveness of treating
various contaminated samples with treatment compositions and
methods as disclosed herein. The samples were treated using
compositions similar to those disclosed in Table 4 using methods
similar to those disclosed herein. Leaching was assessed by method
EPA 1311. Results are listed in Table 5. TABLE-US-00005 TABLE 5
HARDNESS (COMPRSSION LEACHING LEACHING STRENGTH) DESCRIPTION BEFORE
AFTER AFTER OF SAMPLE Contaminant TREATMENT TREATMENT TREATMENT Tar
laden clay Antimony 42.5 ug/g 0.09 ug/l 1.8 MPa soil Arsenic 115
ug/g 0.03 ug/l Lead 625 ug/g Non Detectable Mod. TPH 130000 Non
Detectable Alkaline clay Benzene 0.072 mg/l 0.021 mg/l 1.65 MPa
soil Toluene 0.142 0.030 Xylene 0.009 <0.002 Ethylbenzene 0.088
0.018
Method: EPA 1311
[0068] As shown the leaching after the treatment was in all cases
reduced compared to leaching before treatment. Also, significant
increase in compressive strength is obtained after treatment.
Similar reductions in leaching and increases in compressive
strength are reasonably expected for a wide variety of hazardous
materials if treated as disclosed herein.
IX. Other Matters
[0069] In the following description and claims, the terms "coupled"
and "connected," along with their derivatives, may be used. It
should be understood that these terms are not intended as synonyms
for each other. Rather, in particular embodiments, "connected" may
be used to indicate that two or more elements are in direct
physical or electrical contact with each other. "Coupled" may mean
that two or more elements are in direct physical or electrical
contact. However, "coupled" may also mean that two or more elements
are not in direct contact with each other, but yet still co-operate
or interact with each other.
[0070] In the description above, for the purposes of explanation,
numerous specific details have been set forth in order to provide a
thorough understanding of the embodiments of the invention. It will
be apparent however, to one skilled in the art, that one or more
other embodiments may be practiced without some of these specific
details. The particular embodiments described are not provided to
limit the invention but to illustrate it. The scope of the
invention is not to be determined by the specific examples provided
above but only by the claims below. In other instances, well-known
structures, devices, and operations have been shown in block
diagram form or without detail in order to avoid obscuring the
understanding of the description.
[0071] It will also be appreciated, by one skilled in the art, that
modifications may be made to the embodiments disclosed herein, such
as, for example, to the sizes, configurations, functions,
materials, and manner of operation of the components of the
embodiments. All equivalent relationships to those illustrated in
the drawings and described in the specification are encompassed
within embodiments of the invention.
[0072] Various operations and methods have been described. Some of
the methods have been described in a basic form, but operations may
optionally be added to and/or removed from the methods. The
operations of the methods may also often optionally be performed in
different order. Many modifications and adaptations may be made to
the methods and are contemplated.
[0073] For clarity, in the claims, any element that does not
explicitly state "means for" performing a specified function, or
"step for" performing a specified function, is not to be
interpreted as a "means" or "step" clause as specified in 35 U.S.C.
Section 112, Paragraph 6. In particular, any potential use of "step
of" in the claims herein is not intended to invoke the provisions
of 35 U.S.C. Section 112, Paragraph 6.
[0074] It should also be appreciated that reference throughout this
specification to "one embodiment", "an embodiment", or "one or more
embodiments", for example, means that a particular feature may be
included in the practice of the invention. Similarly, it should be
appreciated that in the description various features are sometimes
grouped together in a single embodiment, Figure, or description
thereof for the purpose of streamlining the disclosure and aiding
in the understanding of various inventive aspects. This method of
disclosure, however, is not to be interpreted as reflecting an
intention that the invention requires more features than are
expressly recited in each claim. Rather, as the following claims
reflect, inventive aspects may lie in less than all features of a
single disclosed embodiment. Thus, the claims following the
Detailed Description are hereby expressly incorporated into this
Detailed Description, with each claim standing on its own as a
separate embodiment of the invention.
[0075] Accordingly, while the invention has been thoroughly
described in terms of several embodiments, those skilled in the art
will recognize that the invention is not limited to the particular
embodiments described, but may be practiced with modification and
alteration within the spirit and scope of the appended claims. The
description is thus to be regarded as illustrative instead of
limiting.
* * * * *