Title of Invention

A METHOD OF TREATING A HYDROLYSATE OF A CHEMICAL AGENT

Abstract A method of treating a hydrolysate of a chemical agent, comprising oxidizing a hydrolysate of a chemical agent to form an aqueous layer and an organic layer, the aqueous layer comprising an organophosphorus concentration and the organic layer comprising an organosulfur concentration; and separating the organic layer from the aqueous layer.
Full Text TREATMENT OF CHEMICAL AGENT HYDROLYSATES
FIELD OF THE INVENTION
The present invention relates generally to methods for the destruction of chemical
weapons. In particular, the present invention relates to novel methods for treating
hydrolysates of chemical agents utilized to construct chemical weapons.
BACKGROUND OF THE INVENTION
Destruction of chemical weapons is a paramount international concern that has
initiated the passage of international treaties, such as the United Nations' Chemical
Weapons Convention Treaty, outlawing chemical weapon development, production, and
stockpiling. More importantly, these international treaties require signatory countries to
effectuate a scheduled destruction of chemical weapon and chemical agent stockpiles.
Destruction of chemical agents is conventionally achieved by means of
incineration. Although incineration represents a technically feasible approach to the
destruction of chemical agents, it is not acceptable to the many State and local
governments and communities neighboring the stockpile sites. The major concerns of
these entities include the perceived health hazards associated with air emissions from
incinerators.
In view of the perceived hazards resulting from incineration, alternative methods
have been developed to destroy chemical agents used in chemical weapons. One
promising alternative method destroys or neutralizes chemical agents by hydrolyzing the
chemical agents. Several significant problems exist, however, in hydrolyzing chemical
agents. One problem is the caustic, odiferous, and toxic nature of the resulting
hydrolysate. Additionally, hydrolysates contain precursors of the chemical agent, which
presents additional problems in relation to regulatory compliance. Chemical weapons
treaties specify that in order to realize complete destruction of a chemical agent, any
precursors capable of reacting to reform the chemical agent must additionally be
destroyed.

In view of these problems, it would be desirable to provide methods for the
treatment of chemical agent hydrolysates that reduce the toxicity of the hydrolysate while
rendering chemical precursors inoperable to react in reforming the hydrolyzed chemical
agent.
SUMMARY OF THE INVENTION
The present invention provides methods for the treatment of chemical agent
hydrolysates. In particular, the present invention successfully enables the treatment of
chemical agent hydrolysates that reduce the toxicity of the hydrolysate while rendering
constituent chemical precursors inoperable to react in reforming the hydrolyzed agent.
In one embodiment, the present invention provides a method comprising
oxidizing a hydrolysate of a chemical agent to form an aqueous layer and an organic
layer; wherein the aqueous layer comprises an organophosphorus concentration and the
organic layer comprises an organosulfur concentration; wherein the organic layer is
separated from the aqueous layer.
In another embodiment, the present invention provides a method comprising
oxidizing a hydrolysate of a chemical agent to form an aqueous layer and an organic
layer, the aqueous layer comprising an organophosphorus concentration and the organic
layer comprising an organosulfur concentration, and oxidizing and precipitating the
organophosphorus concentration from the aqueous layer.
In another embodiment, the present invention provides a method comprising
oxidizing an organophosphorus concentration of a chemical agent hydrolysate solution
and precipitating the oxidized organophosphorus from the hydrolysate solution.
A feature and advantage of the present invention is that methods of the present
invention may be used for the treatment of chemical agent hydrolysates resulting in the
destruction of chemical agent precursors thereby ensuring compliance with international
chemical weapon treaties.
With the foregoing and other advantages and features of the invention that will
become hereinafter apparent, the nature of the invention may be more clearly understood
by reference to the following non-limiting detailed description of the invention and the
several views illustrated in the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is an illustration of one environment for implementation of an
embodiment of the present invention.
Figure 2 illustrates a flowchart for a method according to an embodiment of the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides methods for the treatment of chemical agent
hydrolysates. Methods of the present invention may be advantageously utilized in the
destruction of chemical agent precursors present in hydrolysates rendering the precursors
incapable of reforming the chemical agent. Hydrolysates of chemical agents comprising
VX, Russian VX (RVX), Sarin (GB), Soman (GD), and Tabun (GA) may be treated in
accordance with methods of the present invention.
Reference is made below to specific embodiments of the present invention. Each
embodiment is provided by way of explanation of the invention, not as a limitation of the
invention. In fact, it will be apparent to those skilled in the art that various modifications
and variations can be made in the present invention without departing from the scope or
spirit of the invention. For instance, features illustrated or described as part of one
embodiment may be incorporated into another embodiment to yield a further
embodiment. Thus, it is intended that the present invention cover such modifications and
variations as come within the scope of the appended claims and their equivalents.
For the purposes of this specification, unless otherwise indicated, all numbers
expressing quantities of ingredients, reaction conditions, and so forth used in the
specification are to be understood as being modified in all instances by the term "about."
Accordingly, unless indicated to the contrary, the numerical parameters set forth in the
following specification are approximations that can vary, depending upon the desired
properties sought to be obtained with the present invention. At the very,least,and not as
an attempt to limit the application of the doctrine of equivalents to the scope of the
Claims, each numerical parameter should at least be construed in light of the number of
reported significant digits and by applying ordinary rounding techniques.

Notwithstanding that the numerical ranges and parameters setting forth the broad
scope of the invention are approximations, the numerical values set forth in the specific
examples are reported as precisely as possible. Any numerical value, however,
inherently contains certain errors necessarily resulting from the standard deviation found
in their respective testing measurements. Moreover, all ranges disclosed herein are to be
understood to encompass any and all subranges subsumed therein, and every number
between the end points. For example, a stated range of "1 to 10" should be considered to
include any and all subranges between (and inclusive of) the minimum value of 1 and the
maximum value of 10; that is, all subranges beginning with a minimum value of 1 or
more, e.g., 1 to 6.1, and ending with a maximum value of 10 or less, e.g., 5.5 to 10, as
well as all ranges beginning and ending within the end points, e.g., 2 to 9, 3 to 8, 3.2 to
9.3, 4 to 7, and finally to each number 1, 2, 3, 4, 5, 6, 7, 8,9 and 10 contained within the
range. Additionally, any reference referred to as being "incorporated herein" is to be
understood as being incorporated in its entirety.
It is further noted that, as used in this specification, the singular forms "a," "an,"
and "the" include plural referents unless expressly and unequivocally limited to one
referent.
In an embodiment, a method of the present invention for treating a hydrolysate of
a chemical agent comprises oxidizing the hydrolysate to form an aqueous layer and an
organic layer, the aqueous layer comprising an organphosphorus concentration and the
organic layer comprising an organosulfur concentration, and separating the organic layer
from the aqueous layer.
Referring now to the drawings in which like numerals indicate like elements
throughout the several figures, Figure 1 is an illustration of one environment for
implementation of an embodiment of the present invention. The environment illustrated
in Figure 1 comprises an apparatus 100 comprising a first treatment tank 101, a second
treatment tank 102, a mixing tank 103, a pre-bioreactor equalization tank 104, an organic
matter supply tank 112, and a bioreactor 110. The apparatus 100 of Figure 1 may further
comprise piping systems 105,106, 107, 108, 109, lll,andll3.
Moreover, Figure 2 is a flowchart illustrating a method according to an
embodiment of the present invention. The method illustrated in Figure 2 is described

with reference to the treatment of a VX nerve agent hydrolysate. Additionally, the
method illustrated in Figure 2 is further described with reference to the environment of
the apparatus 100 of Figure 1. The presently described method, however, is not limited
to a hydrolysate of a VX nerve agent, nor is it limited to the environment of the apparatus
100 of Figure 1. Other chemical agents, such as Russian VX (RVX), may be degraded
according to the presently described method.
A VX nerve agent hydrolysate and a first oxidant may be disposed in a first
treatment tank (101) 201. The VX nerve agent hydrolysate, for example, may flow into
the first treatment tank (101) through a piping system (105). Oxidants suitable for
serving as a first oxidant in the present method may comprise hydrogen peroxide (H2O2),
oxygen, ozone, air, hypochlorite, persulfate, permanganate, or any combination thereof.
The first oxidant oxidizes chemical components of the hydrolysate to generate an
aqueous layer and an organic layer, the aqueous layer comprising an organophosphorus
concentration and the organic layer comprising an organosulfur concentration 202. In the
present embodiment, water-soluble thiolamines, such as 2-(Diisopropylamino) ethanthiol
present in the VX hydrolysate are oxidized to water-insoluble disulfides. The oxidant
may be added in a stoichiometric amount to oxidize substantially all of the thiolamine
concentration to a disulfide concentration. In embodiments where the added oxidant
decomposes due to side reactions with the hydrolysate, the amount of oxidant added may
exceed the stoichiometric amount. Moreover, the stoichiometric amount of oxidant
added may vary depending on the identity of the oxidant chosen, but a molar ratio of
oxidizing agent to thiolamine will generally range from about 0.5 to 1 to about 5 to 1.
The oxidation of water-soluble thiolamines into water-insoluble disulfides generates an
organic layer containing the disulfides. Moreover, the aqueous layer formerly containing
the water-soluble thiolamines of VX hydrolysate, as well as other organophosphorus
compounds, now comprises various phosphonic acids such as methylphosphonic acid
(MPA) and ethylmethylphosphonic acid (EMPA). Introduction of a first oxidant to the
chemical agent hydrolysate immediately initiates the oxidation reaction. In some
embodiments of the present invention, oxidation of the chemical agent hydrolysate by a
first oxidant may be allowed to continue for up to one (1) hour.

After production of an aqueous layer comprising an organophosphorus
concentration and an organic layer comprising an organosulfur concentration, the organic
layer may be separated from the aqueous layer by removing the organic layer to a second
treatment tank (102) 203. The organic layer may be removed to a second treatment tank
(102) through a piping system (106) which places the first treatment tank (101) in
communication with the second treatment tank (102). The aqueous layer remains in the
first treatment tank (101).
After separation of the organic layer from the aqueous layer, the
organophosphorus concentration may be removed from the aqueous layer. Removing the
organophosphorus concentration from the aqueous layer comprises oxidizing the
organophosphorus concentration, precipitating the oxidized organophosphorus
concentration comprising inorganic and organic phosphorus compounds from the
aqueous layer, and separating the precipitated phosphorus concentration from the
aqueous layer. As previously described, the phosphorus concentration of the aqueous
layer comprises methyl phosphonic acid (MPA) and/or ethylmethylphosphonic acid
(EMPA). Oxidation of these chemical species may lead to their irreversible
decomposition since carbon-phosphorus bonds are attacked in the oxidation process
thereby removing the methyl group from the phosphorus atom. Irreversible
decomposition of these VX chemical agent precursors may preclude their recombination
with thiolamines in reconstructing the chemical agent thereby ensuring chemical
compliance with international chemical warfare treaties.
Oxidation of the organophosphorus concentration of the aqueous layer comprises
adding a metal catalyst, second oxidant, and pH adjusting chemical species to the first
treatment tank (101) 204. Oxidants suitable for serving as a second oxidant comprise
peroxides, such as hydrogen peroxide, oxygen, ozone, air, hypochlorite, or any
combination thereof. The second oxidant may be added in a stoichiometric amount to
oxidize substantially all the MPA and EMPA in the aqueous layer. The molar ratio of
second oxidizing agent to MPA and EMPA may be from about 5 to 1 to about 40 to 1.
Metal catalysts suitable for use in the oxidation of MPA and EMPA may
comprise iron, magnesium, or combinations thereof. Iron catalysts comprising divalent
(Fe+2) and trivalent iron (Fe+3), for example, may be obtained from commercial entities

known to those skilled in the art such as Beckart Environmental, Inc. of Kenosha,
Wisconsin. The stoichiometric amount of metal catalyst added to the aqueous layer may
be sufficient to produce a molar ratio of metal catalyst to MPA and EMPA ranging from
about 0.5 to 1 to about 3 to 1.
A pH adjusting chemical species may be added to the aqueous layer in a sufficient
amount to adjust the pH of the layer to reside within a pH range from about 4.5 to about
6.0. Suitable pH adjusting chemical species for addition to the aqueous layer may
comprise sodium hydroxide, lye, and/or potassium hydroxide.
The second oxidant, metal catalyst, and pH adjusting species are mixed with the
aqueous layer such as by stirring and the resulting solution may be allowed to sit for any
time period, during which oxidation may occur. In some embodiments, depending on the
concentration of the chemical agent hydrolysate, the time period for oxidation of the
aqueous layer may range from about 15 minutes to about 10 hours. In the oxidation
process, EMPA in the aqueous layer may be oxidized to MPA while MPA in the aqueous
layer may be oxidized to ortho-phosphorus (PO43). MPA and ortho-phosphate are
susceptible to precipitation from an aqueous mixture as iron-phosphorus polymers. As a
result, when iron is present in the aqueous layer, the MPA and ortho-phosphate
produced in the oxidation of the aqueous layer by the second oxidant precipitates as an
iron-phosphorus polymer 205. In embodiments of the present invention, additional
trivalent iron may be added to the aqueous solution after oxidation to precipitate further
amounts of MPA and ortho-phosphate as iron-phosphorus polymer.
The resulting iron-phosphorus polymer precipitate may be separated from the
aqueous solution in the first treatment tank by filtration 206 or any other means known to
one of ordinary skill in the art. Once separated, the iron-phosphorus polymer precipitate
may be combined with other solid waste such as plant material and safely disposed of in a
suitable location, such as a landfill. The removal of the iron-phosphorus polymer
generates an aqueous layer depleted of phosphorus containing compounds.
Similarly, the organosulfur concentration may be removed from the organic layer.
Removing the organosulfur concentration from the organic layer comprises, for example,
oxidizing the organosulfur concentration of the organic layer to form a single aqueous

layer, combining the single aqueous layer with the phosphorus-depleted aqueous layer
and biological material to produce a mixture, and biologically degrading the mixture.
As previously described, the organosulfur layer produced by oxidation of the VX
hydrolysate comprises disulfides. Oxidation of the disulfides in a second treatment tank
(102) comprises adding a third oxidant, water, and a pH adjusting chemical species to the
organic layer in the second treatment tank (102) 208. Oxidants suitable for serving as a
third oxidant comprise a metal catalyst such as iron in conjunction with oxygen, ozone,
air, hypochlorite, peroxides such as hydrogen peroxide, or any combination thereof. The
third oxidant may be added in a stoichiometric amount to oxidize substantially all of the
disulfide concentration in the organic layer. The molar ratio of third oxidizing agent to
disulfide concentration may range from about 3 to 1 to about 30 to 1.
A pH adjusting chemical species may be added to the organic layer in a sufficient
amount to adjust the pH of the layer to reside with a pH range from about 4.5 to about
6.0. Suitable pH adjusting chemical species for addition to the organic layer comprise
sodium hydroxide, lye, and/or potassium hydroxide. Water may be added to the organic
layer at a volume of 2.5 times the volume of the organic layer.
The third oxidant, pH adjusting species, and water are mixed by stirring, and the
resulting solution may be allowed to sit for any time period, during which oxidation may
occur. The oxidation of disulfides in the organic layer transforms the organic layer into a
single aqueous layer in the second treatment tank (102) 209. Disulfides in the organic
layer may be oxidized to various water-soluble sulfates thereby transforming the organic
layer into a single aqueous-layer.
The single aqueous layer formed by the oxidation of the organic layer in the
second treatment tank (102) may be combined with the phosphorus-depleted aqueous
layer of the first treatment tank (101) 210. Combination of the single aqueous layer with
the phosphorus-depleted aqueous layer may comprise mixing the two aqueous layers in a
mixing tank (103). In other embodiments, the single aqueous layer formed by the
oxidation of the organic layer in the second treatment tank (102) may be returned to the
first treatment tank (101) for combination with the phosphorus-depleted aqueous layer.
The aqueous solution resulting from the combination of the single aqueous layer
in the second treatment tank (102) with the phosphorus-depleted layer of the first

treatment tank (101) may be transferred to a pre-bioreactor equalization tank (104) 211
where the aqueous solution may be commingled with organic material such as plant flow.
The plant flow may be introduced in the pre-bioreactor (104) from an organic matter
storage tank (112) in communication with the pre-bioreactor through a piping system
(113). The aqueous solution may be biodegraded in a bioreactor (110) downstream from
the equalization tank (104) 212. When operated in batch mode the bioreactor may
require a time period of 6-24 hours for degradation of the treated hydrolysate. The
bioreactor may have a hydraulic residence time of 5-20 days and a solids retention time
of 20-100 days.
After biological degradation (212), the aqueous solution may be separated from
solid matter in the bioreactor (110) 213. Separation of the aqueous solution from solid
matter may be achieved through filtration of the solution or by any other separation
technique known to one of ordinary skill in the art. Sedimentation, for example, may be
another method by which the aqueous solution may be separated from solid matter in the
bioreactor (110). The separated aqueous solution may be tested for permitted effluent
limits and Schedule 2 compounds before being discharged. The separated aqueous
solution may be discharged, for example, into a local publicly owned treatment works as
non-hazardous water.
The solids removed from the aqueous solution in the bioreactor (110) may be
commingled with the phosphorus precipitate produced in the removal of the
organophosphorus concentration from the aqueous layer in the first treatment tank (101)
214. The commingled solids may be disposed in an appropriate landfill 207.
In some embodiments, the phosphorus-depleted aqueous layer may proceed
directly to the biodegradation step (212) without being mixed with the single aqueous
layer produced from the oxidation of an organosulfur concentration. The pH of the
phosphorus-depleted aqueous layer may be adjusted to reside within a range from about 6
to 8 and further treated biologically prior to discharge. The biologically treated
phosphorus-depleted aqueous layer may be discharged, for example, into a publicly
owned treatment works or may discharged or otherwise disposed of in any manner
known to one of ordinary skill in the art. In other embodiments, the phosphorus-depleted

aqueous layer may be combined with additional waste streams comprising biologically
degradable compounds before undergoing biological treatment.
Similarly, in some embodiments, the single aqueous phase produced from the
oxidation of the organic layer comprising an organosulfur concentration may proceed
directly to the biodegradation step (212) without being mixed with the phosphorus-
depleted aqueous layer. Moreover, the single aqueous layer may be mixed with other
waste streams comprising biologically degradable compounds before undergoing
biological treatment. The biologically treated single aqueous layer may be discharg
into a body of water such as a publicly owned treatment works or may otherwise be
disposed of in any manner known to one of ordinary skill in the art.
In other embodiments, oxidation products of the organosulfur compounds
produced in the oxidation of the organic layer comprising an organosulfur concentration
may be precipitated with metal salts comprising iron. Ferric chloride and/or ferrous
sulfate, for example, may be used to precipitate organosulfur compounds produced in the
oxidation of the organic layer comprising an organosulfur concentration.
In a further embodiment, a chemical agent hydrolysate may be treated with a first
oxidant as previously described to form an aqueous layer and an organic layer, the
aqueous layer comprising an organophosphorus concentration and the organic layer
comprising an organosulfur concentration. The organic layer may be separated from the
aqueous layer. Subsequent to separation from the aqueous layer, the organic layer may
be treated with an oxidant, pH adjusting species, and water as previously described.
Moreover, the organophosphorus concentration may be removed from the aqueous layer
in the absence of a second oxidant by the addition of a metal salt. Metal ions of the salts
may precipitate the phosphorus containing compounds, such as MPA and ortho-
phosphorus, from the aqueous layer as metal-phosphorus polymers. Metal salts suitable
for precipitating the phosphorus containing compounds in the aqueous phase according to
the present embodiment may comprise those of iron. Ferrous sulfate and ferric chloride,
for example, may precipitate phosphorus containing compounds from the aqueous layer.
The aqueous layer may be filtered to remove the phosphorus containing precipitate to
form a phosphorus-depleted aqueous layer. The phosphorus-depleted aqueous layer and

oxidized organic layer may be recombined and biodegraded in a bioreactor as previously
described.
In another embodiment, a method of the present invention comprises oxidizing a
hydrolysate of a chemical agent to form an aqueous layer and an organic layer, the
aqueous layer comprising an organophosphorus concentration and the organic layer
comprising an organosulfur concentration, and oxidizing and precipitating the
organophosphorus concentration from the aqueous layer. The present method is similar
to the preceding method described with reference to Figures 1 and 2. In the present
method, however, the organic layer is not separated from the aqueous layer subsequent to
the initial oxidation.
According to the present method, a hydrolysate of a chemical agent and a first
oxidant may be disposed in a treatment tank or vessel. Oxidants suitable for serving as a
first oxidant in the present method may comprise hydrogen peroxide, oxygen, ozone, air,
hypochlorite, persulfate, permanganate, or any combination thereof. The first oxidant
oxidizes chemical components of the hydrolysate to generate an aqueous layer and an
organic layer, the aqueous layer comprising an organophosphorus concentration and the
organic layer comprising an organosulfur concentration. Water soluble thiolamines, such
as 2-(Diisopropylarnino) -ethanethiol- present in the chemical agent hydrolysate are
oxidized into water insoluble disulfides. The oxidant may be added in a stoichiometric
amount to oxidize substantially all of the thiolamine concentration into a disulfide
concentration. In embodiments where the oxidant decomposes due to side reactions in
the hydrolysate, the amount* of oxidant added may exceed the stoichiometric amount.
Moreover, the stoichiometric amount of oxidant may vary depending on the identity of
the oxidant chosen, but a molar ratio of oxidizing agent to thiolamine will generally range
from about 0.5 to 1 to about 5 tol. The oxidation of water-soluble thiolamines into
water-insoluble disulfides generates an organic layer containing the disulfides.
Moreover, the aqueous layer formerly containing the water-soluble thiolamines of the
hydrolysate, as well as other organophosphorus compounds, comprises various
phosphonic acids such as methylphosphonic acid (MPA) and ethylmethylphosphonic acid
(TEMPA). Introduction of a first oxidant to the chemical agent hydrolysate immediately
initiates the oxidation reaction. In some embodiments of the present invention, oxidation

of the chemical agent hydrolysate by a first oxidant may be allowed to continue for up to
one (1) hour.
After production of an aqueous layer and organic layer, the organophosphorus
concentration of the hydrolysate may be oxidized and precipitated from the aqueous
layer. Oxidation and precipitation of the organophosphorus concentration comprises
adding a second oxidant, metal catalyst, and pH adjusting species to the hydrolysate
solution. The hydrolysate solution at this juncture comprises the aqueous layer and
organic layer as the step of separating the organic layer from the aqueous layer has been
omitted in the present method. Oxidants suitable for serving as a second oxidant in the
present method are similar those oxidants which may serve as a second oxidant in the
preceding method. Suitable second oxidants for the present method comprise oxygen,
air, hypochlorite, and peroxides such as hydrogen peroxide and/or ozone. The second
oxidant may be utilized in conjunction with a metal catalyst such as iron.
The oxidant may be added in a stoichiometric amount to oxidize substantially all
of the organophosphorus concentration in the hydrolysate solution. The molar ratio of
the oxidizing agent to the organophosphorus concentration may range from about 1 to 1
to about 40 to 1. Moreover, the stoichiometric amount of metal catalyst added to the
hydrolysate solution may be sufficient to produce a molar ratio of metal catalyst to
organophosphorus concentration ranging from about 0.5 to 1 to about 3 to 1.
A pH adjusting chemical species may be added to the hydrolysate solution in a
sufficient amount to adjust the pH of the solution to reside with a pH range from about
4.5 to about 6.0.
The oxidant, metal catalyst, and pH adjusting species are mixed with the
hydrolysate solution in the first treatment tank by stirring, and the resulting solution may
be allowed to sit for any time period, during which oxidation may occur. In some
embodiments, depending on the concentration of the chemical agent hydrolysate, the time
period for oxidation of the hydrolysate solution may range from about 15 minutes to
about 10 hours. In the oxidation reaction, the organophosphorus concentration is
oxidized to methyl-phosphonic acid (MPA) and ortho-phosphate (PO43). As previously
described, MPA and ortho-phosphorus are susceptible to precipitation from an aqueous
mixture as iron-phosphorus polymers. As a result, when iron is present in the hydrolysate

solution, the MPA and ortho-phosphorus produced in the oxidation of the hydrolysate
solution may precipitate as an iron-phosphorus polymer. In other embodiments,
additional trivalent iron may be introduced into the first treatment tank after oxidation to

precipitate further amounts of MPA and ortho-phosphate as iron-phosphorus polymer.
The resulting iron-phosphorus polymer precipitate may be separated from the
hydrolysate solution in the first treatment tank by filtration or any other means known to
one or ordinary skill in the art. Once separated, the iron-phosphorus polymer precipitate
may be combined with other solid waste such as plant material and safely disposed of in a
landfill. The removal of the non-phosphorus polymer generates a depleted
organophosphorus aqueous layer and renders organophosphorus precursors of a chemical
agent hydrolysate incapable of reforming the chemical agent.
The organophosphorus depleted hydrolysate solution may subsequently proceed
to a pre-bioreactor equalization tank and bioreactor (110) for biodegradation. In some
embodiments, the oxidation of the hydrolysate solution by the second oxidant may
consume the organic layer comprising the organosulfur concentration. In such
embodiments, the organic layer is transformed into a substantially aqueous layer
comprising inorganic and organic sulfates. This newly formed aqueous layer comprising
sulfates may be miscible with the phosphorus-depleted aqueous layer and subsequently
proceeds to the biodegradation step with the phosphorus-depleted aqueous layer.
In biodegrading the organophosphorus depleted hydrolysate solution, the pH of
the hydrolysate solution is adjusted to reside within a range from about 6 to 8. The
organophosphorus hydrolysate solution may be combined with plant and/or other organic
material and subsequently biodegraded. The biodegraded organophosphorus depleted
hydrolysate solution may be discharged into a body of water such as a publicly owned
treatment works or may be disposed of in any other manner known to one of ordinary
skill in the art.
In some embodiments, before biodegradation, the organophosphorus depleted
hydrolysate solution may be combined with other waste streams comprising biologically
degradable compounds.
In another embodiment of the present invention, a method comprises oxidizing an
orgnophosphorus concentration of a chemical agent hydrolysate solution and

precipitating the oxidized organophosphorus concentration from the hydrolysate solution.
Hydrolysates suitable for use with the present method comprise hydrolysates containing a
water-soluble organophosphorus concentration. Hydrolysates of Sarin (GB), Soman
(GD), and Tabun (GA) in addition to the aqueous component of an oxidized VX
hydrolysate, for example, are suitable for treatment by the present method.
The oxidation and precipitation of the organophosphorus concentration of a
hydrolysate solution may occur in a manner substantially similar to the removal of the
organophosphorus concentration from the aqueous layers described in the previous
methods. It is important to note that oxidation of the hydrolysate solution in the present
method does not produce an organic layer thereby precluding the need to for an initial
oxidation step comprising a first oxidant.
Accordingly, a hydrolysate solution, oxidant, metal catalyst, and pH adjusting
species may be disposed in a first treatment tank. Oxidants, metal catalysts, and pH
adjusting chemical species suitable for the oxidation process of the present method are
similar to those described for the oxidation of the aqueous organophosphorus
concentration in the preceding methods. Suitable oxidants for the present method, for
example, are similar those which may serve as a second oxidant in the preceding methods
and comprise peroxides, such as hydrogen peroxide and ozone, oxygen, air, and
hypochlorite. The oxidant is utilized in conjunction with a metal catalyst such as iron.
The oxidant may be added in a stiochiometric amount to oxidize substantially all
of the organophosphorus concentration in the hydrolysate solution. The molar ratio of
the oxidizing agent to the organophosphorus concentration may range from about 1 to 1
to about 40 to 1. Moreover, the stoichiometric amount of metal catalyst added to the
hydrolysate solution may be sufficient to produce a molar ratio of metal catalyst to
orgnophosphorus-concentration ranging from about 0.5 to 1 to about 3 to 1.
A pH adjusting chemical species may be added to the hydrolysate solution in a
sufficient amount to adjust the pH of the solution to reside with a pH range from about
4.5 to about 6.0.
The oxidant, metal catalyst, and pH adjusting species are mixed with the
hydrolysate solution in the first treatment tank by stirring, and the resulting solution may
be allowed to sit for a time period during which oxidation may occur. In some

embodiments, depending on the concentration of the chemical agent hydrolysate, the time
period for oxidation of the hydrolysate solution may range from about 15 minutes to
about 10 hours. In the oxidation reaction, the organophosphorus concentration is
oxidized to methyl-phosphonic acid (MPA) and ortho-phosphorus (PO43). As previously
described, MPA and ortho-phosphorus are susceptible to precipitation from an aqueous
mixture of as iron-phosphorus polymers. As a result, when iron is present in the
hydrolysate solution, the MPA and ortho-phosphorus produced in the oxidation of the
hydrolysate solution may precipitate as an iron-phosphorus polymer. In other
embodiments, additional trivalent iron may be introduced into the first treatment tank
after oxidation to precipitate further amounts of MPA and ortho-phosphorus as iron-
phosphorus polymer.
The resulting iron-phosphorus polymer precipitate may be separated from the
hydrolysate solution in the first treatment tank by filtration or any other means known to
one or ordinary skill in the art. Once separated, the iron-phosphorus polymer precipitate
may be combined with other solid waste such as plant material and safely disposed of in a
landfill. The removal of the iron-phosphorus polymer generates a depleted
organophosphorus aqueous layer and renders organophosphorus precursors of a chemical
agent hydrolysate incapable of reforming the chemical agent.
The organophosphorus depleted hydrolysate solution may subsequently proceed
to a pre-bioreactor equalization tank for biodegradation. In biodegrading the
organophosphorus depleted hydrolysate solution, the pH of the hydrolysate solution is
adjusted to reside within a range from about 6 to 8. The organophosphorus hydrolysate
solution may be combined with plant and/or other organic material and subsequently
biodegraded. The biodegraded organophosphorus depleted hydrolysate solution may be
discharged into a body of water such as a publicly owned treatment works or may be
disposed of in any other manner known to one of ordinary skill in the art.
In some embodiments, before biodegradation, the organophosphorus depleted
hydrolysate solution may be combined with other waste streams comprising biologically
degradable compounds.

About 3.8 liters (one gallon) of VX hydrolysate comprising 10% VX load [1 M
thiolamine, 1 M phosphonates (EMPA and MPA)] and a pH of 14 is disposed in a first
treatment tank or reaction vessel. The VX hydrolysate is stirred, and about 230 mL of
50% hydrogen peroxide (H2O2) is added to oxidize the VX hydrolysate in the first
treatment tank. The oxidation of the VX hydrolysate produces an aqueous layer
comprising an organophosphorus concentration and an organic layer comprising an
organosulfur concentration. In the present example, the organic layer is not separated
from the aqueous layer.
The pH of the oxidized, hydrolysate solution is adjusted to a value of about 8 with
the addition of about 270 mL of concentrated sulfuric acid. The hydrolysate solution is
then subjected to a second oxidation. In the oxidation process, about 4 liters of 5-7%
aqueous iron as FeS04 * 7H2O is added to the solution. The pH of the hydrolysate
solution is further adjusted to about 6 with concentrated sulfuric acid. The solution is
heated to 50°C and about 8 liters of 50% hydrogen peroxide (H2O2) is added to the
hydrolysate solution over a 4 hour period. The pH of the solution is maintained at a pH
of 5 with 50% sodium hydroxide (NaOH) and the temperature of the hydrolysate solution
is maintained between 60°C and 90°C over the course of the oxidation. The hydrolysate
solution is allowed to cool for 1 hour.
The resulting phosphorus containing precipitate is filtered from the solution with
a filter press. The phosphorus containing precipitate is disposed of accordingly. The
ammonia concentration of the phosphorus-depleted hydrolysate solution is stripped from
the solution. The pH of the phosphorus depleted hydrolysate solution is adjusted to a
value of 12 with 50% sodium hydroxide (NaOH). Generally, the addition of about 500
mL of NaOH is required to adjust the pH of the solution to a value of 12. The
hydrolysate solution is subsequently sparged with air until ammonia specifications are
met (about 2 h to 50 mg/L).
The phosphorus-depleted solution is blended with plant flow such that the total
dissolved solids (TDS) level is less than 3%. The blended solution is added to an
acclimated, aerated sequencing batch reactor (SBR). The microorganism ratio
(TOC:MLSS) in the SBR is about equal to 0.2 wherein TOC = total organic carbon and

MLSS = mixed liquor suspended solids. The blended phosphorus-depleted solution is
biodegraded and the resulting effluent is discharged from the biological treatment system.
The effluent is discharged at a hydraulic retention time (HRT) of about 10 days. The
effluent may be polished if necessary to meet permit requirements. Settled solids may be
discharged at a solids-retention time (SRT) of about 50 days.
Table 1: Concentrations of Schedule 2 Compounds and CBOD5 in the Hydrolysate
Treatment Process (in Percent)

Table 1 displays the results of treatment of a VX hydrolysate according to a
method of the present invention. As illustrated in Table 1, the organophosphorus
concentration of the hydrolysate is significantly reduced thereby rendering the
organophosphorus precursors inoperable to recombine with other chemical species in the
hydrolysate to reform the chemical agent.
The foregoing description of embodiments of the present invention has been
presented only for the purpose of illustration and description and is not intended to be
exhaustive or to limit the invention to the precise forms disclosed. Numerous
modifications and adaptations thereof will be apparent to those skilled in the art without
departing from the spirit and scope of the present invention.

WE CLAIM:
1. A method of treating a hydrolysate of a chemical agent comprising:
oxidizing a hydrolysate of a chemical agent to form an aqueous layer
and an organic layer, the aqueous layer comprising an
organophosphorus concentration and the organic layer comprising an
organosulfur concentration; and
separating the organic layer from the aqueous layer.
2. The method as claimed in claim 1, wherein organophosphorus
concentration comprises methyl phosphonic acid.
3. The method as claimed in claim 2, wherein the organophosphorus
concentration further comprises ethylmethyl phosphonic acid.
4. The method as claimed in claim 1, wherein the organosulfur
concentration comprises disulfide compounds.
5. The method as claimed in claim 1, wherein the chemical agent
comprises at least one of XV and RVX nerve agent.

6. The method as claimed in claim 1, further comprising removing the
organophosphorus concentration from the aqueous layer to produce a
depleted organophosphorus aqueous layer.
7. The method as claimed in claim 6, wherein removing the
organophosphorus concentration from the aqueous layer comprises:
oxidizing in a manner such as herein described, the
organophosphorus concentration;
precipitating the oxidized organophosphorus concentration from the
aqueous layer; and
separating the precipitated organophosphorus concentration from the
aqueous layer.
8. The method as claimed in claim 7, wherein the aqueous layer
comprises a pH from 4.5 to 6.0.
9. The method as claimed in claim 7, wherein precipitating comprises
adding a precipitating agent to the aqueous layer.
10. The method as claimed in claim 9, wherein the precipitating agent
comprises an iron source.

11. The method as claimed in claim 7, wherein separating the
precipitated oxidized organophosphorus concentration from the
aqueous layer comprises filtering the aqueous layer.
12. The method as claimed in claim 7, further comprising disposing of
the removed phosphorus concentration.
13. The method as claimed in claim 12, wherein disposing comprises
placing the removed organophosphorus concentration in a landfill.
14. The method as claimed in claim 1, further comprising removing the
organosulfur concentration from the organic layer.
15. The method as claimed in claim 14, wherein removing the
organosulfur concentration from the organic layer comprises:
oxidizing in a manner such as herein described, the organosulfur
concentration of the organic layer to form a single aqueous layer;
combining the single aqueous layer with the depleted
organophosphorus aqueous layer and biological material to produce a
mixture; and
biologically degrading the mixture.

16. The method as claimed in claim 15, wherein the organic layer
comprises a pH from 3 to 5.
17. The method as claimed in claim 15, further comprising disposing of
the biologically degraded mixture.
18. The method as claimed in claim 17, wherein disposing of the
biologically degraded mixture comprises:
filtering the mixture to produce an effluent and a solid phase;
discharging the effluent into a water source; and
placing the solid phase in a landfill.


A method of treating a hydrolysate of a chemical agent, comprising oxidizing
a hydrolysate of a chemical agent to form an aqueous layer and an organic
layer, the aqueous layer comprising an organophosphorus concentration and the
organic layer comprising an organosulfur concentration; and separating the
organic layer from the aqueous layer.

Documents:

00336-kolnp-2006-abstract.pdf

00336-kolnp-2006-claims.pdf

00336-kolnp-2006-description complete.pdf

00336-kolnp-2006-drawings.pdf

00336-kolnp-2006-form-1.pdf

00336-kolnp-2006-form-2.pdf

00336-kolnp-2006-form-3.pdf

00336-kolnp-2006-form-5.pdf

00336-kolnp-2006-international publication.pdf

336-KOLNP-2006-(07-10-2011)-CORRESPONDENCE.pdf

336-KOLNP-2006-(07-10-2011)-OTHERS.pdf

336-kolnp-2006-abstract.pdf

336-kolnp-2006-amanded claims.pdf

336-kolnp-2006-assignment.pdf

336-kolnp-2006-claims.pdf

336-KOLNP-2006-CORRESPONDENCE 1.1.pdf

336-kolnp-2006-correspondence.pdf

336-kolnp-2006-description (complete).pdf

336-kolnp-2006-drawings.pdf

336-KOLNP-2006-EXAMINATION REPORT 1.1.pdf

336-kolnp-2006-examination report.pdf

336-kolnp-2006-form 1.pdf

336-KOLNP-2006-FORM 18 1.1.pdf

336-kolnp-2006-form 18.pdf

336-kolnp-2006-form 2.pdf

336-KOLNP-2006-FORM 26 1.1.pdf

336-kolnp-2006-form 26.pdf

336-KOLNP-2006-FORM 27.pdf

336-KOLNP-2006-FORM 3 1.1.pdf

336-kolnp-2006-form 3.pdf

336-KOLNP-2006-FORM 5 1.1.pdf

336-kolnp-2006-form 5.pdf

336-KOLNP-2006-GRANTED-ABSTRACT.pdf

336-KOLNP-2006-GRANTED-CLAIMS.pdf

336-KOLNP-2006-GRANTED-DESCRIPTION (COMPLETE).pdf

336-KOLNP-2006-GRANTED-DRAWINGS.pdf

336-KOLNP-2006-GRANTED-FORM 1.pdf

336-KOLNP-2006-GRANTED-FORM 2.pdf

336-KOLNP-2006-GRANTED-SPECIFICATION.pdf

336-KOLNP-2006-OTHERS.pdf

336-KOLNP-2006-REPLY TO EXAMINATION REPORT 1.1.pdf

336-kolnp-2006-reply to examination report.pdf

336-kolnp-2006-specification.pdf

abstract-00336-kolnp-2006.jpg


Patent Number 252427
Indian Patent Application Number 336/KOLNP/2006
PG Journal Number 20/2012
Publication Date 18-May-2012
Grant Date 15-May-2012
Date of Filing 15-Feb-2006
Name of Patentee PERMA-FIX ENVIRONMENT SERVICES, INC
Applicant Address 1940 NW 67TH PLACE GAINESVILLE, FLORIDA
Inventors:
# Inventor's Name Inventor's Address
1 MARX, RANDALL B. 3102 CHADBOURNE ROAD, SHAKER HEIGHTS, OH 44120
2 SCHNEIDER, STEVE 33800 SLEEPY HOLLOW, LIVONIA, MI 48150
3 STATON, JOHN 267 MILLS PLACE, NEW LEBANON, OH 45345
4 CENTOFANTI, LOU F. 815 WILDERLAKE COURT, ATLANTA, GA 30328
5 BADGER, DAVID 991 STATE ROUTE 169, NEW GALILEE, PA 16141
6 IRVINE, DAVID A. 200 E. DELAWARE PLACE, #8B, CHICAGO, IL 60611
PCT International Classification Number A62D 3/00
PCT International Application Number PCT/US2004/026537
PCT International Filing date 2004-08-16
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 60/495,620 2003-08-15 U.S.A.
2 80/495,312 2003-08-15 U.S.A.
3 80/495,621 2003-08-15 U.S.A.