U.S. patent application number 11/229758 was filed with the patent office on 2006-02-23 for systems and methods for producing aqueous solutions and gases having disinfecting properties and substantially eliminating impurities.
This patent application is currently assigned to Avantec Technologies, Inc.. Invention is credited to James Liang-Hiong Chia, Bernardo N. Rico, Margaret Emily Williams.
Application Number | 20060039841 11/229758 |
Document ID | / |
Family ID | 37906469 |
Filed Date | 2006-02-23 |
United States Patent
Application |
20060039841 |
Kind Code |
A1 |
Rico; Bernardo N. ; et
al. |
February 23, 2006 |
Systems and methods for producing aqueous solutions and gases
having disinfecting properties and substantially eliminating
impurities
Abstract
A system for disinfecting and purifying aqueous solutions and
water for drinking purposes comprising an outer pouch, a
disinfectant generating device, and an inorganic coagulant. The
disinfectant generating device is provided with a membrane shell
defining at least two compartments which house a first reactant, a
second reactant, and an inorganic coagulant. The disinfectant
generating device is capable of producing a disinfectant when
exposed to water or moisture and the disinfectant exits the
compartment through the membrane shell. The inorganic coagulant aid
the formation of flocs of the suspended dispersed particles in the
aqueous solution.
Inventors: |
Rico; Bernardo N.; (Lewis
Center, OH) ; Chia; James Liang-Hiong; (Columbus,
OH) ; Williams; Margaret Emily; (Columbus,
OH) |
Correspondence
Address: |
SPECKMAN LAW GROUP PLLC
1501 WESTERN AVE
SEATTLE
WA
98101
US
|
Assignee: |
Avantec Technologies, Inc.
Columbus
OH
|
Family ID: |
37906469 |
Appl. No.: |
11/229758 |
Filed: |
September 19, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10921385 |
Aug 18, 2004 |
|
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11229758 |
Sep 19, 2005 |
|
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60610809 |
Sep 17, 2004 |
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Current U.S.
Class: |
422/305 |
Current CPC
Class: |
C02F 2305/04 20130101;
C02F 1/5236 20130101; C02F 1/56 20130101; A61L 2/208 20130101; A01N
59/02 20130101; C01B 11/025 20130101; C01B 11/024 20130101; C02F
2303/04 20130101; A61L 2/186 20130101; C02F 1/76 20130101; A01N
59/04 20130101; A01N 59/00 20130101; A01N 37/16 20130101; C02F
1/688 20130101 |
Class at
Publication: |
422/305 |
International
Class: |
B01J 7/00 20060101
B01J007/00 |
Claims
1. A system for producing a disinfectant comprising: an outer
pouch; a disinfectant generating device stored within the outer
pouch; and at least one inorganic coagulant stored within the outer
pouch, wherein the disinfectant generating device comprises a
membrane shell defining at least two compartments, the compartments
containing a first dry reactant and a second dry reactant, wherein
each compartment is provided with an outer membrane defining walls
of the device and a wick means providing physical separation of the
first and second dry reactants, whereby the first and second dry
reactants react with each other upon exposure of the device to
water or moisture to generate a disinfectant, and whereby the
disinfectant exits the compartments through the membrane shell of
the device.
2. The system of claim 1, wherein the at least one inorganic
coagulant may be stored outside of and separated from or within the
disinfectant generating device and is selected from the group
consisting of: ferric sulfate, ferric chloride, ferrous sulfate,
aluminum sulfate, polyaluminum chloride, sodium aluminate,
chlorinated copper, and mixtures thereof.
3. The system of claim 1, further comprising at least one polymeric
coagulant, wherein the at least one polymeric coagulant is stored
outside of and separated from the disinfectant generating device
and is selected from the group consisting of: cationic
polyelectrolytes, polyDADMAC, epiDMA, anionic polyelctrolytes,
nonionic polyelctrolytes, polyacrylamide polymers, copolymers,
terpolymers, organic polymers, water extract, moringa oleifera,
chitin, and mixtures thereof within the disinfectant generating
device.
4. The system of claim 3, wherein the at least one polymeric
coagulant is stored within the disinfectant generating device.
5. The system of claim 1, further comprising at least one
hydrophilic colloid stored within the outer pouch, wherein the at
least one hydrophilic colloid is stored outside of and separated
from or within the disinfectant generating device, and wherein the
at least one hydrophilic colloid is selected from the group
consisting of: activated silica, bentonite, and mixtures
thereof.
6. The system of claim 1, wherein the disinfectant generating
device further comprises at least one water soluble membrane
sealably connected to an outer membrane of the device, forming a
third compartment.
7. The system of claim 6, wherein at least one surfactant is stored
within the third compartment of the disinfectant generating
device.
8. The system of claim 7, wherein the at least one surfactant is
selected from the group consisting of: anionic surfactant, linear
alkylbenzene sulfonate, alcohol ethyoxysulfates, alkyl sulfate,
nonionic surfactant, alcohol ethoxylate, cationic surfactant,
quaternary ammonium compounds, amphoteric surfactants, imidazoline,
betaines, and mixtures thereof.
9. The system of claim 6, wherein at least one fragrance material
is stored within the third compartment of the disinfectant
generating device.
10. The system of claim 9, wherein the at least one fragrance
material is selected from the group consisting of: linalyl formate,
isoamyl acetate, and mixtures thereof.
11. The system of claim 6, wherein at least one additive is stored
within the third compartment of the disinfectant generating
device.
12. The system of claim 11, wherein the at least one additive is
selected from the group consisting of: suds stabilizers, alkylamine
oxides, suds suppressors, alkyl phosphates, antiredeposition
agents, polycarbonates and polyethylene, colorants, pigments, dyes,
corrosion inhibitors, odium silicate, opacifiers, titanium dioxide,
polymers, processing aids, clays, sequestrants, chelating agents,
sodium citrate, complex phosphates, EDTA, precipitating agents,
sodium carbonate, sodium silicate, ion exchange builders, zeolites,
and mixtures thereof.
13. The system of claim 1, wherein the first dry reactant and the
second dry reactant are in a form selected from the group
consisting of: powders, granules, pellets, tablets, agglomerates,
and mixtures thereof.
14. The system of claim 1, wherein the first dry reactant and the
second dry reactant are in a form of a tablet.
15. The system of claim 1, wherein the first dry reactant is
selected from the group consisting of: sodium chlorite, calcium
chlorite, potassium chlorite, barium chlorite, magnesium chlorite,
alkali metal chlorites, alkaline earth metal chlorites, sodium
chlorate, tetraacetylethylenediamine (TAED), sodium bromide, sodium
bisulfite, alkali metal chlorites, alkaline earth metal chlorites,
and mixtures thereof.
16. The system of claim 1, wherein the second dry reactant is
selected from the group consisting of: sodium bisulphate, citric
acid, mandelic acid, boric acid, lactic acid, tartaric acid, maleic
acid, malic acid, glutaric acid, adipic acid, acetic acid, formic
acid, sulfamic acid, sulfuric acid, hydrochloric acid, phosphoric
acid, fumaric acid, phosphoric anhydride, sulfuric anhydride, water
soluble organic acid anhydrides, maleic anhydride, water soluble
acid salts, calcium chloride, magnesium chloride, magnesium
nitrate, lithium chloride, magnesium sulfate, aluminum sulfate,
sodium acid sulfate, sodium dihydrogen phosphate, potassium acid
sulfate, potassium dihydrogen phosphate, sodium persulfate, oxalic
acid, peroxygen compounds, sodium percarbonate, sodium perborate,
urea hydrogen peroxide, potassium monopersulfate, and mixtures
thereof.
17. The system of claim 1, wherein the disinfectant is selected
from a group consisting of: chlorine dioxide, peracetic acid,
chlorous acid, hydrogen peroxide, bromine, sulfur dioxide, carbon
dioxide, and mixtures thereof.
18. A tablet for producing a disinfectant, comprising a first dry
reactant, a second dry reactant, and an inorganic coagulant,
whereby the first and second dry reactants of the tablet react with
each other upon exposure of the tablet to water or an aqueous
solution to generate a disinfectant in the solution.
19. A device for producing a vapor having disinfecting properties
when exposed to ambient moisture, comprising: at least two outer
membranes permeable to moisture and vapor; and at least one inner
membrane sealed to the at least two outer membranes along at least
two edges of the device, wherein the outer membranes and the inner
membrane together form a first compartment and a second compartment
separated by the inner membrane, wherein the first compartment is
provided with a first dry reactant and the second compartment is
provided with a second dry reactant, whereby the vapor having
disinfecting properties is generated and released to the atmosphere
from the device when the first dry reactant in the first
compartment is hydrated by moisture penetrating the outer
membranes, and the hydrated first dry reactant is transported
across the inner membrane to contact the second dry reactant in the
second compartment to generate the vapor having disinfecting
properties.
20. The device of claim 19, further comprising at least one
deliquescent material stored within the first compartment or the
second compartment of the device.
21. A system for producing a disinfectant selected from the group
consisting of: peracetic acid, chlorous acid, hydrogen peroxide,
bromine, sulfur dioxide, and carbon dioxide, comprising: a
disinfectant generating device comprising a membrane shell defining
at least two compartments; a first reactant selected from the group
consisting of: tetraacetylethylenediamine (TAED), sodium bromide,
sodium bisulfite, sodium carbonate, and chlorite compounds; and a
second reactant selected from the group consisting of: peroxygen
compounds, sodium percarbonate, sodium perborate, urea hydrogen
peroxide, potassium monopersulfate compounds, citric acid, fumaric
acid, and other acid compounds.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent
Application No. 60/610,809, filed Sep. 17, 2004, and is a
continuation-in-part of U.S. patent application Ser. No.
10/921,385, filed Aug. 18, 2004.
FIELD OF THE INVENTION
[0002] The present invention relates generally to systems and
methods for producing disinfectants and substantially eliminating
impurities, and particularly to systems that produce a disinfectant
when exposed to water or ambient moisture.
BACKGROUND OF THE INVENTION
[0003] Chlorine dioxide (ClO.sub.2) is a relatively small,
volatile, and versatile free radical molecule with bleaching,
oxidizing, and deodorizing properties, as well as antimicrobial
properties, namely, bactericidal, viricidal, sporicidal, algicidal,
and fungicidal properties. It is frequently used to control
microorganisms on or around food products because chlorine dioxide
destroys the microorganisms without producing concentrations of
byproducts that would pose a significant adverse risk to human
health. Examples of these adverse byproducts that may be produced
by other types of oxidants include chloramines and chlorinated
organic compounds. Chlorine dioxide's physiological mode of
destroying microbes has been attributed to the destruction of cell
walls and cell membranes and disrupting transport of nutrients from
the external environment into microorganisms.
[0004] Chlorine dioxide has also long been recognized for treatment
and reduction of odors caused by compounds and microorganisms
through an oxidation process. Examples of odor-causing compounds
include: sulfur-containing compounds (hydrogen sulfide, mercaptan
sulfides, organic disulfide, sulfoxides, etc.), oxygen containing
compounds (phenols, aldehydes, aliphatic alcohols, etc.) and some
nitrogen containing compounds (tertiary and secondary amines,
etc.). A low concentration of chlorine dioxide, in either gaseous
or liquid state, is effective for most antimicrobial and
deodorization applications. In addition to chlorine dioxide, other
compounds, such as peracetic acid, bromine, sulfur dioxide, and
carbon dioxide also exhibit antimicrobial and disinfecting
properties.
[0005] As an oxidizing biocide, chlorine dioxide can also be used
as a disinfectant or as an oxidant in water treatment systems. It
may be used in both the pre-oxidation and the post-oxidation stages
of the treatment as a primary oxidant or as a primary or secondary
disinfectant. By adding chlorine dioxide in the pre-oxidation phase
of the purification of surface water, the growth of bacteria and
algae can be controlled in the subsequent phases of the treatment.
Chlorine dioxide also acts as an oxidant to the colloidal
substances, aiding in the coagulation process and improving the
removal of turbidity.
[0006] In its vapor state, chlorine dioxide is not stable during
storage and can be explosive at concentrations above about 10% in
dry air. At temperatures lower than -40.degree. C., chlorine
dioxide vapor can be compressed to a liquid state to reduce the
risk of explosion; above this temperature, however, highly
concentrated liquid chlorine dioxide can be explosive. Therefore,
chlorine dioxide vapor or liquid is usually not produced and
shipped under pressure. Instead, chlorine dioxide is typically
generated at the point of use via conventional chlorine dioxide
generators or other means. Conventional chlorine dioxide generation
can be carried out in an efficient manner for large-scale
operations to produce chlorine dioxide by reacting sodium chlorite
or sodium chlorate solution with an acid such as sulfuric acid,
hydrochloric acid, or a reducing agent. Chlorine dioxide can also
be generated by one of the following reactions: mixing sodium
chlorite solution with a strong chlorine solution at low pH, mixing
a sodium chlorite solution with chlorine gas at near neutral pH
under a vacuum, or reacting solid sodium chlorite in a sealed
reactor cartridge with humidified chlorine gas flowing through it.
All of the processes mentioned above require expensive generation
equipment, high maintenance costs, and highly trained and skilled
workers to operate the equipment in a safe manner. As a result, the
use of such generators has been limited to the fields of poultry
processing, pulp and paper bleaching, and water treatment
facilities, where the high capital and operating cost of the
generators can be justified by the large consumption of chlorine
dioxide.
[0007] In addition to the methods discussed above, chlorine dioxide
can also be generated by the electrolysis of sodium chlorite
solutions. This process requires electricity to operate the
electrolytic equipment, and high maintenance efforts to ensure the
efficiency of the equipment. The electrolysis process not only
produces less chlorine dioxide compared to conventional generators,
but special sodium chlorite solutions are also required for this
process to reduce the level of suspended solids and scaling that
can clog the electrolytic cell. Further, proportional amount of
wastes, such as sodium hydroxide solution, are produced along with
chlorine dioxide during the electrolytic reaction.
[0008] A solution of a metal chlorite and water where the pH of the
solution is maintained at 8 or above is sometimes referred to as a
"stabilized chlorine dioxide" solution. Applications requiring
small quantities of chlorine dioxide can be approached by the use
of "stabilized chlorine dioxide", which generally refers to sodium
chlorite, a reactant of chlorine dioxide. Sodium chlorite by itself
only has bacteriostatic properties (inhibits rather than killing
bacteria) and does not provide complete disinfection. Some claims
have been made to the use of sodium chlorite as a bactericide in
situations in which bacteria can provide the necessary acidity for
the "activation" step to produce chlorine dioxide. In any case, the
amount of chlorine dioxide produced under these conditions is
insignificant. In most other cases, "stabilized chlorine dioxide"
still requires the activation step of reacting a sodium chlorite
solution with an acid. The pH of the reacting solution must be
lowered to below 5, typically to a pH range between about 2 to
about 3, in order to produce chlorine dioxide according to the
following equation:
5ClO.sub.2.sup.-+5H.sup.+.fwdarw.4ClO.sub.2+HCl+2H.sub.2O This
approach or any other type of "two-part system" is usually
performed at the application site, requiring trained personnel to
properly activate the product. In addition, the use of "stabilized
chlorine dioxide" requires mixing equipment and manipulation of
potentially dangerous acids, thus exposing users to inadvertent
skin contact and inhalation of acid vapors. Transportation of the
"stabilized chlorine dioxide" also involves large volumes of water,
resulting in a costly and difficult operation for remote and/or
disaster recovery uses.
[0009] Attempts have also been made to manufacture devices that
produce chlorine dioxide using a mixture of solid sodium chlorite
and acidulant in solid forms (e.g. citric acid, sodium bisulfate,
organic anhydride, etc.). These devices usually require complicated
formulation processes, one of which involves drying individual
reactants to lower their water content, and mixing the dried
reactants in the presence of desiccant materials (e.g. calcium
chloride) to prevent the premature generation of chlorine dioxide
that is initiated by atmospheric moisture, Such processes must take
place in specially-designed environments that minimize moisture
contact with mixed reactants during the formulation/packaging
process. In addition, a protective barrier is required to prevent
the contact of atmospheric moisture with the mixed reactants prior
to use. In the presence of water/moisture, these devices generate
chlorine dioxide solution or chlorine dioxide vapor. Due to the
nature of the manufacturing process, these devices usually involve
high manufacturing costs.
[0010] Many compositions and methods for generating chlorine
dioxide solutions are known in the art. For example, U.S. Pat. No.
2,022,262 discloses stable stain-removing compositions made from a
dry mixture of water-soluble alkaline chlorite salt, an oxalate,
and an, acid. U.S. Pat. No. 2,071,091 discloses the use of chlorous
acid and chlorites to kill fungi and bacterial organisms by
exposing the organisms to the compounds at a pH of less than about
7. The patent also discloses using dry mixtures of chlorites and
acids to produce stable aqueous solutions useful as bleaching
agents. U.S. Pat. No. 2,482,891 discloses stable, solid,
substantially anhydrous compositions comprising alkaline chlorite
salts and organic acid anhydrides, which release chlorine dioxide
when contacted with water. U.S. Pat. No. 2,071,094 discloses
deodorizing compositions in the form of dry briquettes formed of a
mixture of soluble chlorite, an acidifying agent, and a filler of
relatively low solubility. Chlorine dioxide is generated when the
briquettes contact water. U.S. Pat. No. 4,585,482 discloses a
long-acting biocidal composition comprising a microencapsulated
mixture of chlorite and acid that when added to water releases
chlorine dioxide. The primary purpose of the microencapsulation is
to provide for hard particles that will be free flowing when
handled. The microencapsulated composition also protects against
water loss from the interior of the microcapsule. The microcapsules
produce chlorine dioxide when immersed in water. The microcapsules
release chlorine dioxide relatively slowly and are therefore not
suitable for applications that require the preparation of chlorine
dioxide on a relatively fast basis. U.S. Pat. No. 6,063,425
discloses a method for disinfecting a meat carcass by spray
application of an aqueous solution containing from about 0.05 to
0.12% of a metal chlorite and a sufficient quantity of an acid
having a pKa of from about 2.0 to 4.4 to adjust the pH of the
aqueous solution to about 2.2-4.5. This adjustment helps to
maintain the chlorite ion concentration in the form of chlorous
acid to not more than about 35% by weight of the aqueous solution,
the molar ratio of the acid to metal chlorite being at least equal
to the first pKa of the acid multiplied by the grams/liter
concentration of metal chlorite in the aqueous solution.
[0011] Many devices and methods for producing chlorine dioxide
solution are also known in the art. For example, Canadian Patent
No. 959,238 discloses using two water-soluble envelopes, one
containing sodium chlorite and the other containing an acid, to
generate chlorine dioxide solution. The envelopes are placed in
water and the sodium chlorite and acid dissolve in the water and
react to produce a chlorine dioxide solution. PCT Application
PCT/US98/22564 (WO 99/24356) discloses a method and device for
producing chlorine dioxide solutions wherein sodium chlorite and an
acid are mixed and enclosed in a semi-permeable membrane device.
When the device is placed in water, water penetrates the membrane.
The acid and sodium chlorite dissolve in the water and react to
produce chlorine dioxide. The chlorine dioxide exits the device
through the membrane into the water in which the device is immersed
producing a chlorine dioxide solution that can be used as an
anti-microbial solution or for other purposes. The primary
disadvantage of the disclosed device and method is that ambient
moisture can penetrate the semi-permeable membrane and initiate the
reaction prematurely.
[0012] In general, the above prior art devices and methods using
membranes are susceptible to premature activation by water or water
vapor and therefore have a reduced shelf life unless sufficient
steps are taken to protect the devices from exposure to ambient
moisture or water. In addition, such devices and methods are
typically slow to interact with water and produce the desired
chlorine dioxide.
[0013] U.S. Pat. No. 6,764,661 discloses a device for producing an
aqueous chlorine dioxide solution when placed in water that solves
the aforementioned problem. One of the advantages of this device is
that it is not susceptible to activation by ambient moisture. The
device includes a membrane shell that defines a compartment, which
includes one or more dry reactants (e.g., a metal chlorite and an
acid) capable of producing chlorine dioxide when exposed to water.
The device is provided with wick means extending between the outer
membranes, creating two inner compartments. The wick means absorb
water and transport it into the compartment by capillary action.
Once water has entered the inner compartments, the reactant(s) in
the compartments dissolve in the water and produce chlorine dioxide
in an aqueous solution. This device is generally used to produce an
aqueous solution, having antimicrobial and disinfecting properties,
when exposed to water. It is not designed to produce a vapor having
antimicrobial and disinfecting properties.
[0014] In some water treatment operations, the process of
coagulation is employed to separate suspended solids from water. In
general, finely dispersed solids (colloids) suspended in water are
stabilized by negative electric charges on their surfaces, causing
them to repel each other. This repulsion prevents the colloids from
colliding and forming larger masses, called "flocs". Coagulation
promotes the aggregation of these colloidal particles to form flocs
by destabilizing their surface charges. For example, cationic
coagulants bond to negatively charged particles, thus lowering the
charge and energy required to bring the colloidal particles into
contact. As a result, the particles collide and form flocs.
[0015] Flocculation is the action of forming bridges between the
flocs and binding the flocs into large agglomerates or clumps.
Bridging occurs when segments of polymer chains of the flocs adsorb
onto different particles, causing the flocs to aggregate. An
anionic flocculant will react against a positively charged
suspension, adsorbing on the particles and causing destabilization
either by bridging or charge neutralization. Once suspended flocs
are flocculated into larger flocs, they can usually be removed from
the liquid by sedimentation, provided that a sufficient density
difference exists between the suspended flocs and the liquid. The
flocs can also be removed or separated by media filtration,
straining, sedimentation, or floatation. Flocculation not only
increases the size of the floc particles, but it also affects the
physical nature of the flocs, making these particles less
gelatinous and thereby easier to remove.
[0016] U.S. Pat. No. 5,023,012 discloses a composition for the
purification of water, including a suitable coagulant for
coagulating solid impurities dispersed in the water to form flocs
and an organic hydrophilic colloid capable, when dispersed in the
water, of absorbing large quantities of water to form a sol for
aggregating the flocs. The proportion of organic hydrophilic
colloid in the composition is such that when the composition is
used to purify the intended quantity of water, the organic
hydrophilic colloid does not interfere with coagulant dispersal in
the water or with floc formation.
[0017] The aforementioned coagulating and purifying invention uses
chlorine as a disinfectant. Recently, concern over the disinfection
byproducts of chlorine has led to increased use of alternative
disinfectants that produce safer byproducts. Chlorine reacts with
organic matter in water to form trihalomethanes (THMs) and
haloacetic acids (HAAs) which have been-found to be
carcinogenic.
[0018] The present invention provides systems and methods for
disinfection and purification that overcome the aforementioned
disadvantages and problems.
SUMMARY OF THE INVENTION
[0019] A system is provided for producing disinfectants and
substantially eliminating impurities upon exposure of the system to
water or moisture. In one embodiment, the inventive system is
provided with a protective outer pouch that contains a disinfectant
generating device for disinfecting water or aqueous solutions and
substantially eliminating microbial contaminants and at least one
inorganic coagulant for substantially removing impurities in water
or the aqueous solutions. The disinfectant generating device
comprises at least two dry reactants, in "powder" form or "tablet"
form, capable of reacting and producing a disinfectant upon
exposure of the device to water or ambient moisture. Examples of
"powder" form include, but are not limited to: powders, granules,
pellets, tablets, agglomerates, and the like. The inorganic
coagulant is generally stored within the outer pouch, being outside
of and separated from the disinfectant generating device.
Alternatively, the inorganic coagulant may be stored within the
disinfectant generating device.
[0020] In addition to the outer pouch, the disinfectant generating
device, and the inorganic coagulant, the inventive system may
additionally include at least one polymeric coagulant for aiding
flocculation of impurities in water or aqueous solutions.
Alternatively, the inventive system may include an outer pouch, a
disinfectant generating device, at least one inorganic coagulant,
and at least one organic hydrophilic colloid to aid the
flocculation of the impurities. In yet another alternative, the
inventive system may include an outer pouch, a disinfectant
generating device, at least one inorganic coagulant, at least one
polymeric coagulant, and at least one organic hydrophilic colloid.
In still another embodiment, the inventive system may include an
outer pouch, a disinfectant generating device containing at least
two dry reactants, at least one surfactant, at least one fragrance
material, at least one additive, or combinations thereof, at least
one inorganic coagulant, and optionally at least one polymeric
coagulant, at least one organic hydrophilic colloid, or a
combination of the polymeric coagulant and the hydrophilic colloid.
Alternatively, the at least one surfactant, the at least one
fragrance material, and the at least one additive may be stored
outside of and separated from the disinfectant generating
device.
[0021] The disinfectant generating device comprises a membrane
shell defining at least two compartments, and each compartment
includes at least one dry reactant capable of reacting and
producing a disinfectant upon exposure of the device to water or
ambient moisture. Each compartment is provided with an outer
membrane defining walls of the device and a wick means or an inner
membrane providing physical separation of the dry reactants. Each
of the at least two compartments may additionally include at least
one inorganic coagulant, at least one polymeric coagulant, at least
one organic hydrophilic colloid, or combinations thereof. Wick
means or the inner membrane is provided in connection with the
membrane shell and extends into one or both compartments for
absorbing water or moisture and transporting water or moisture into
at least one of the compartments, facilitating the reaction and
producing a disinfectant in the compartment, and the disinfectant
exits the compartment through the membrane shell.
[0022] In another embodiment of the disinfectant generating device,
the device may additionally be provided with at least one water
soluble membrane. The water-soluble membrane is sealed
substantially continuously along the edges to one of the outer
membranes of the device, for example, using a mechanical
heat-sealing process, to form a third compartment of the device.
Alternatively, the device may additionally be provided with at
least two water soluble membranes and each of the at least two
water soluble membranes is sealed substantially continuously to one
of the outer membranes of the device along the edges to form a
third compartment and a fourth compartment of the device. The third
compartment and the fourth compartment may each contain at least
one inorganic coagulant, at least one polymeric coagulant, at least
one organic hydrophilic colloid, at least one surfactant, at least
one fragrance material, at least one additive, or combinations
thereof.
[0023] The at least two dry reactants, under reaction conditions,
generate a disinfectant such as chlorine dioxide, peracetic acid,
bromine, sulfur dioxide, carbon dioxide, and the like. In one
embodiment, in which disinfectant generated in the device is
chlorine dioxide, the first compartment of the device includes a
metal chlorite component and the second compartment includes an
acid component.
[0024] In an alternative embodiment of the inventive system, the
system is provided with a package comprising a protective outer
pouch and at least one tablet having disinfectant properties being
stored within the outer pouch. The at least one disinfectant tablet
may contain at least two dry reactants, at least one inorganic
coagulant, at least one polymeric coagulant, at least one organic
hydrophilic colloid, or a combination of the polymeric coagulant
and the organic hydrophilic colloid. The disinfectant tablet may
additionally contain at least one surfactant, at least one
fragrance material, an additive, or a combination thereof. Upon
use, the disinfectant tablet may be removed from the outer pouch
and submerged in water or aqueous solutions for generating a
disinfectant and substantially eliminating impurities in the water
or aqueous solutions. Alternatively, the outer pouch may be
constructed of a water soluble material and the entire package may
be submerged in water or aqueous solutions upon use.
[0025] To disinfect and remove impurities from water and aqueous
solutions, the elements of the inventive system are immersed in and
added to water or an aqueous solution, and the water or solution is
stirred and allowed to settle. The disinfectant generating device
and the disinfectant tablet serve to substantially eliminate
microbial contaminants in the water or solution; the inorganic
coagulant promotes the aggregation of the solid impurities to form
flocs; the polymeric coagulant and organic hydrophilic colloid aid
in flocculation and clarification of a solution to be treated; and
the surfactant helps the removal of soil from the solution to be
treated or a surface and the reduction of surface tension of the
solution to be treated.
[0026] In an embodiment where the inventive system is provided with
a disinfectant generating device or a disinfectant tablet
containing first and second reactants, an inorganic coagulant, and
optionally a polymeric coagulant, an organic hydrophilic colloid, a
surfactant, a fragrance material, an additive, or combinations
thereof, the disinfection and purification process is commenced by
opening the outer pouch of the system and placing the disinfectant
generating device or the disinfectant tablet into a vessel, or the
like, containing a predetermined volume of water or an aqueous
solution. To promote dispersal of disinfectant and the
coagulant(s), the aqueous solution is stirred and then allowed to
settle, after which, the solution may be decanted and then filtered
to remove the impurities.
[0027] In another embodiment where an inorganic coagulant, a
polymeric coagulant, an organic hydrophilic colloid, a surfactant,
a fragrance material, an additive, or combinations thereof are
stored independently from the disinfectant generating device or
disinfectant tablet, the inorganic coagulant, the polymeric
coagulant, the organic hydrophilic colloid, the surfactant, the
fragrance material, the additive, or combinations thereof are first
added to the vessel of water or an aqueous solution. The aqueous
solution is stirred to allow flocs to form. The solution is then
allowed to settle, after which, the disinfectant generating device
or disinfectant tablet is placed in the aqueous solution.
[0028] For the generation of vapor or gases having disinfectant
properties, the inventive system comprises a disinfectant vapor
generating device for producing vapor having disinfectant
properties upon exposure of the device to ambient moisture. The
device is capable of providing sustained generation of vapor having
disinfectant properties over a long period of time (weeks to
months). The device is provided with an inner membrane that is
sealed to at least outer membranes continuously or non-continuously
along the edges of the device, via a mechanical heat sealing
process, to form at least two compartments of the device and each
of the at least two compartment contains at least one dry reactant
and optionally at one deliquescent material. The inner membrane
physically separates the dry reactants and is capable of absorbing
and transporting small amounts of one of the partially dissolved
reactants across the inner membrane to react with the other
reactant in a separate compartment. When the device is exposed to
the environment, the ambient moisture penetrates the outer
membranes. The dry reactants then become hydrated and slowly
dissolve. The partially dissolved reactants come into contact with
each other across the inner membrane to produce a disinfectant
vapor. Eventually, the generated disinfectant vapor slowly diffuses
out of the outer membranes into the surrounding environment.
[0029] In another embodiment, the disinfectant vapor generating
device comprises an inner membrane and two outer membranes, which
are sealed together non-continuously along the edges of the device,
to form a pouch having a plurality of small openings along the
edges of the device for facilitating passage of moisture into the
device. The small openings or gaps may be mechanically compressed
to prevent the reactants from falling out from the device. These
small openings increase the moisture transfer rate into the device,
the reactants' dissolution rate, the rate of generation of the
disinfectant vapor generation, as well as the rate of facilitating
the passage of disinfectant vapor out of the device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Preferred embodiments of the present invention are described
in detail below and illustrated in the drawings, in which:
[0031] FIG. 1 shows a front perspective view of an embodiment of
the inventive system, having an outer pouch that contains a
disinfectant generating device;
[0032] FIG. 2 shows a cross-sectional view of another embodiment of
the inventive system, illustrating an outer pouch containing a
disinfectant generating device and an inorganic coagulant stored
outside of the disinfectant generating device in the outer
pouch;
[0033] FIG. 3 shows a cross-sectional view of yet another
embodiment of the inventive system, illustrating an outer pouch
containing a disinfectant generating device, and an inorganic
coagulant, a polymeric coagulant, and an organic hydrophilic
colloid stored outside of the disinfectant generating device in the
outer pouch;
[0034] FIG. 4 shows a cross-sectional view of still another
embodiment of the inventive system, illustrating an outer pouch
containing a disinfectant generating device, and an inorganic
coagulant stored inside of the disinfectant generating device;
[0035] FIG. 5 shows a cross-sectional view of an alternative
embodiment of the inventive system, illustrating an outer pouch
provided with a disinfectant generating device containing two
reactant tablets;
[0036] FIG. 6 shows a cross-sectional view of another alternative
embodiment of the inventive system, illustrating an outer pouch
provided with an inorganic coagulant and a disinfectant generating
device containing two reactant tablets and an inorganic coagulant
stored outside of the device in the outer pouch;
[0037] FIG. 7 shows a cross-sectional view of yet another
alternative embodiment of the inventive system, illustrating an
outer pouch provided with an inorganic coagulant, a polymeric
coagulant, an organic hydrophilic colloid, and a disinfectant
generating device containing two reactant tablets;
[0038] FIG. 8 shows a cross-sectional view of a further embodiment
of the inventive system, illustrating an outer pouch provided with
a reactant tablet, an inorganic coagulant, a polymeric coagulant,
and a hydrophilic colloid;
[0039] FIG. 9 shows a cross-sectional view of another further
embodiment of the inventive system, illustrating an outer pouch
provided with a reactant tablet an inorganic coagulant, a polymeric
coagulant, a hydrophilic colloid, a surfactant, a fragrance
material, and an additive;
[0040] FIG. 10 shows a cross-sectional view of yet another further
embodiment of the inventive system, illustrating an outer pouch
provided with a reactant tablet;
[0041] FIG. 11 shows a cross-sectional view of another further
embodiment of the inventive system, illustrating an outer pouch
provided with an inorganic coagulant, a polymeric coagulant, a
hydrophilic colloid, and a disinfectant generating device
containing two dry reactants and being provided with two water
soluble membranes sealed to the outer membranes of the device,
forming outer compartments that contain a surfactant, a fragrance
material, and an additive;
[0042] FIG. 12 shows a cross-sectional view of the device shown in
FIG. 11, illustrating outer compartments provided with an inorganic
coagulant, a polymeric coagulant, a hydrophilic colloid, a
surfactant, a fragrance material, an additive; and
[0043] FIG. 13 shows a front elevational view of a disinfectant
vapor-generating device having a plurality of small openings along
the edges of the device for facilitating passage of moisture into
the device.
DETAILED DESCRIPTION OF THE INVENTION
[0044] A system is provided for the production of disinfectants and
substantially eliminating microbial contaminants, such as bacteria,
viruses, and parasites, as well as removal of impurities upon
exposure to water or moisture. In one embodiment, the inventive
system is provided with a protective outer pouch, a disinfectant
generating device including at least two dry reactants for the
production of a disinfectant, and at least one inorganic coagulant
for removing impurities in water or other aqueous solutions. In
addition to the disinfectant generating device and the inorganic
coagulant, the system may optionally be provided with at least one
polymeric coagulant, at least one organic hydrophilic colloid, or a
combination of the at least one polymeric coagulant and at least
one organic hydrophilic colloid for aiding flocculation of the
impurities in water or aqueous solutions. The inventive system may
additionally be provided with at least one surfactant, a fragrance
material, an additive, or a combination thereof. The disinfectant
generating device, which will be described in further details
below, may be in a configuration defined by at least two
compartments and each compartment includes at least one dry
reactant for producing a disinfectant. The disinfectant generating
device may be further provided with at least one water soluble
membrane sealed continuously to an outer membrane of the device
along its edges to form a third compartment of the device. The dry
reactants, the inorganic coagulant, the polymeric coagulant, the
organic hydrophilic colloid, the surfactant, the fragrance
material, the addictive, and combinations thereof may be in
"powder" form or "tablet" form. As used herein and in the claims,
the term "powder form" means components in a stable, solid,
substantially anhydrous form that include, but are not limited to:
powders, granules, pellets, tablets, agglomerates, and the like.
The disinfectant produced by the inventive system may include, but
is not limited to, chlorine dioxide, peracetic acid, chlorous acid,
bromine, and the like.
[0045] In another embodiment of the inventive system, the system is
provided with an outer pouch and at least one disinfectant
generating tablet for producing a disinfectant. The tablet may
contain at least two dry reactants, at least one inorganic
coagulant, at least one polymeric coagulant, at least one organic
hydrophilic colloid, at least one surfactant, at least one
fragrance material, an additive, or combinations thereof.
[0046] FIG. 1 shows inventive system 100 comprising a package
having a sealed or sealable outer pouch 105 that contains a
disinfectant generating device 102. The outer pouch 105 may be
constructed of a lightweight, strong, vapor-impermeable, and tear
and abrasion-resistant material such as, but is not limited to,
aluminum, aluminum foil, polyethylene, and the like, and
combinations thereof.
[0047] In one embodiment of the inventive system 100, shown in FIG.
2, a disinfectant generating device 102 and at least one inorganic
coagulant 304 are stored in outer pouch 105 of system 100. The
disinfectant generating device 102, for example, is provided with
at least two compartments 30A, 30B and each compartment 30A, 30B
contains a first dry reactant 40A and a second dry reactant 40B in
powder form capable of producing a biocide or disinfectant when the
reactants 40A, 40B react with water or moisture. Inorganic
coagulant 304 may include, but is not limited to, ferric sulfate,
ferric chloride, ferrous sulfate, aluminum sulfate, polyaluminum
chloride, sodium aluminate, chlorinated copper, and the like. In
the embodiment shown in FIG. 2, inorganic coagulant 304 may be
stored in outer pouch 105 and outside of and separated from
disinfectant generating device 102. Alternatively, as shown in FIG.
4, inorganic coagulant 304 may be stored inside of compartments
30A, 30B of disinfectant generating device 102. In one embodiment,
inventive system 100 contains approximately between 0-90% by mass
first dry reactant 40A, approximately between 0-90% by mass second
dry reactant 40B, and approximately between 0-40% by mass inorganic
coagulant 304. In another embodiment, system 100 contains
approximately between 10-50% by mass of each of the first and
second dry reactants 40A, 40B and approximately between 0-40% by
mass of inorganic coagulant 304.
[0048] FIG. 3 shows another embodiment of inventive system 100
provided with outer pouch 105 containing a disinfectant generating
device 102 including a first dry reactant 40A and a second dry
reactant 40B, and a mixture of at least one inorganic coagulant 304
and at least one polymeric coagulant 310 stored outside of and
separated from device 102. Alternatively, the mixture of inorganic
coagulant 304 and polymeric coagulant 310 may be stored inside of
compartments 30A, 30B of disinfectant generating device 102. In
another alternative, inorganic coagulant 304 may be stored inside
of device 102 and polymeric coagulant 310 may be stored outside of
device 102. In yet another alternative, polymeric coagulant 310 may
be stored inside of device 102 and inorganic coagulant 304 may be
stored outside of device 102. Polymeric coagulant 310 may include,
but is not limited to, cationic polyelectrolytes, polyDADMAC,
epiDMA, and anionic and nonionic polyelctrolytes such as
polyacrylamide polymers, copolymers, and terpolymers. Organic
polymers such as the water extract, Moringa oleifera, and chitin
can also be used as polymeric coagulant 310. In one embodiment,
inventive system 100 contains approximately between 0-90% by mass
first dry reactant 40A, approximately between 0-90% by mass second
dry reactant 40B, approximately between 0-40% by mass inorganic
coagulant 304, and approximately between 0-40% polymeric coagulant
310. In another embodiment, system 100 contains approximately
between 10-50% by mass of each of the first and second dry
reactants 40A, 40B, approximately between 0-40% by mass of the
inorganic coagulant, and approximately between 0-40% by mass
polymeric coagulant 310.
[0049] In another embodiment, as illustrated by FIG. 3, outer pouch
105 of system 100 contains a disinfectant generating device 102
having a first dry reactant 40A and a second dry reactant 40B, a
mixture of at least one inorganic coagulant 304 and at least one
organic hydrophilic colloid 312 stored outside of and separated
from disinfectant generating device 102. Alternatively, the mixture
of inorganic coagulant 304 and organic hydrophilic colloid 312 may
be stored inside of device 102. In another alternative, inorganic
coagulant 304 may be stored inside of device 102 and organic
hydrophilic colloid 312 may be stored outside of device 102. In yet
another alternative, organic hydrophilic colloid 312 may be stored
inside of device 102 and inorganic coagulant 304 may be stored
outside of device 102. Hydrophilic colloid 312 may include, but is
not limited to, activated silica and bentonite. In one embodiment,
inventive system 100 contains approximately between 0-90% by mass
first dry reactant 40A, approximately between 0-90% by mass second
dry reactant 40B, approximately between 0-40% by mass inorganic
coagulant 304, and approximately between 0-40% by mass organic
hydrophilic colloid 312. In another embodiment, system 100 contains
approximately between 10-50% by mass of each of the first and
second dry reactants 40A, 40B, approximately between by mass 0-40%
of inorganic coagulant 304, and approximately between 0-40% by mass
of organic hydrophilic colloid 312.
[0050] In yet another embodiment, outer pouch 105 of system 100
contains a disinfectant generating device 102 having a first dry
reactant and a second dry reactant 40A, 40B, a mixture of at least
one inorganic coagulant 304, at least one polymeric coagulant 310,
and at least one organic hydrophilic colloid 312 stored outside of
and separated from device 102. Alternatively, the mixture of
inorganic coagulant 304, polymeric coagulant 310, and organic
hydrophilic colloid 312 may be stored inside of compartments 30A,
30B of device 102. In another alternative, any two of inorganic
coagulant 304, polymeric coagulant 310, and hydrophilic colloid 312
may be stored inside of device 102 and any one of inorganic
coagulant 304, polymeric coagulant 310, and hydrophilic colloid 312
may be stored outside of device 102. In yet another alternative,
any one of inorganic coagulant 304, polymeric coagulant 310, and
hydrophilic colloid 312 may be stored inside of device 102 and any
two of inorganic coagulant 304, polymeric coagulant 310, and
hydrophilic colloid 312 may be stored outside of device 102. In one
embodiment, inventive system 100 contains approximately between
0-90% by mass first dry reactant 40A, approximately between 0-90%
by mass second dry reactant 40B, approximately between 0-50% by
mass inorganic coagulant 304, approximately between 0-40% by mass
polymeric coagulant 310, and approximately between 0-40% by mass
organic hydrophilic colloid 312. In another embodiment, system 100
contains approximately between 10-50% by mass of each of the first
and second dry reactants, approximately between 0-40% by mass of
the inorganic coagulant 304, approximately between 0-30% by mass
polymeric coagulant 310, and approximately between by mass 0-30%
organic hydrophilic colloid 312.
[0051] FIG. 5 shows another embodiment of the inventive system 100
provided with an outer pouch 105 and a disinfectant generating
device 102 including a first dry reactant and a second dry reactant
in tablet form 44A, 44B. Each tablet 44A, 44B may include at least
one inorganic coagulant. Alternatively, powder form of inorganic
coagulant may be stored inside of compartments 30A, 30B of
disinfectant generating device 102, but separated from tablets 44A
and 44B. Still alternatively, as shown in FIG. 6, powder form of
inorganic coagulant 304 may be stored in outer pouch 105 and
outside of and separated from disinfectant generating device
102.
[0052] FIG. 7 shows another embodiment of inventive system 100
provided with an outer pouch 105, a disinfectant generating device
102 including a first dry reactant 44A and a second dry reactant
44B in tablet form, and at least one inorganic coagulant 304, at
least one polymeric coagulant 310, at least one hydrophilic colloid
312, or any combinations thereof, in powder form, stored outside of
and separated from device 102. Alternatively, the powder form of
inorganic coagulant 304, polymeric coagulant 310, hydrophilic
colloid 312, or any combinations thereof may be stored inside of
compartments 30A, 30B of disinfectant generating device 102, but
separated from reactant tablets 44A and 44B. In another
alternative, tablets 44A and 44B, containing first dry reactant,
second dry reactant, inorganic coagulant 304, polymeric coagulant
310, and hydrophilic colloid 312 are stored inside of compartments
30A and 30B of device 102. In yet another alternative, tablets 44A
and 44B, containing first dry reactant, second dry reactant, and
inorganic coagulant 304 may be stored inside of device, while
powder form of polymeric coagulant 310, hydrophilic colloid 312, or
combinations thereof may be stored outside of device 102. In still
another alternative, tablets 44A and 44B, containing first dry
reactant, second dry reactant, and polymeric coagulant 310 may be
stored inside of device, while powder form of inorganic coagulant
304, hydrophilic colloid 312, or combinations thereof may be stored
outside of device 102. In a further alternative embodiment, tablets
44A and 44B, containing first dry reactant, second dry reactant,
and hydrophilic colloid 312 may be stored inside of device, while
powder form of inorganic coagulant 304, polymeric coagulant 310, or
combinations thereof may be stored outside of device 102.
[0053] In yet a further alternative embodiment, tablets 44A and
44B, containing first dry reactant, second dry reactant, and any
one, two, or combinations of inorganic coagulant 304, polymeric
coagulant 310, and hydrophilic colloid 312 may be stored inside of
compartments 30a and 30B of device 102, while powder form of any
one, two, or combinations of inorganic coagulant 304, polymeric
coagulant 310, and hydrophilic colloid 312 may be stored outside of
and separated from device 102.
[0054] The disinfectant generating device 102 may include different
configurations, e.g., round, triangle, rectangle, parallelogram,
trapezoid, diamond, octagon, hexagon, oval, and combinations
thereof, to suit different applications. The disinfectant
generating device 102 is capable of producing aqueous solutions
having antimicrobial and disinfecting properties upon exposure to
water and other aqueous solutions. Some examples of antimicrobial
and disinfectants include, but are not limited to, chlorine
dioxide, peracetic acid, chlorous acid, hydrogen peroxide, bromine,
sulfur dioxide, and carbon dioxide.
[0055] As shown in FIGS. 1-7, the disinfectant generating device
102 comprises a membrane shell 22 defining at least two
compartments 30A, 30B. Each compartment 30A, 30B is provided with
an outer membrane 22A and 22B defining walls of device 102. Wick
member 24 is provided in connection with membrane shell 22 and
extends into one or both compartments 30A and 30B. Each compartment
contains at least one dry reactants in stable, solid, and
substantially anhydrous powder form 40A, 40B, or tablet form 44A,
44B. These reactants are capable of producing a disinfectant when
the device 102 is exposed to water or moisture. The device 102 is
preferably exposed to water by placing or submerging it in a
container of water.
[0056] Referring to FIGS. 1-7, wick member 24 is sealably connected
to outer membranes 22A and 22B, dividing disinfectant generating
device 102 into two compartments, 30A and 30B. Due to the nature of
the membrane employed, wick member 24 functions through capillary
action, rapidly absorbing water from outside device 102 and
transporting the absorbed water into the compartments 30A and 30B.
When dry reactants 40A, 40B stored in compartments 30A and 30B
dissolve in the absorbed water and react to produce a disinfectant,
the disinfectant efficiently exits compartments 30A and 30B through
outer membranes 22A and 22B or through gaps in the seal of the
three layers 22A, 22B, and 24, and possibly, to some extent,
through wick member 24.
[0057] Wick member 24 may be connected to outer membranes 22A and
22B by being directly or indirectly fastened to a portion or all of
outer membranes 22A and 22B. Once submerged in water, wick member
24 transports water or solution into the inner compartments 30A and
30B through capillary action. At the same time, a pressure
differential between the interior and exterior of the disinfectant
generating device 102 causes water to enter device 102 through the
gaps in the seals 50A, 50B, 50C, and 50D. As the reaction proceeds,
the pressure differential between inside and outside of device 102
equilibrates and the exchange of water and solution slows to
eventually reach equilibrium.
[0058] As shown by FIGS. 1-7, disinfectant generating device 102
may be defined by two outer membranes 22A and 22B sealed together
such that compartments 30A and 30B are formed between the panels.
Outer membranes 22A and 22B may be sealed together along a line
which extends around the periphery of outer membranes 22A and 22B
just inside of the outer edge of device 102. Specifically, the seal
extends along line 50A adjacent to the top edge, along line 50B
adjacent to the side edge, along line 50C adjacent to the bottom
edge, and along line 50D adjacent to the opposite side edge of
device 102. Outer membranes 22A and 22B may be sealed together by a
variety of means known in the art, including, but not limited to,
heat sealing, stitching, heating, and gluing. For example, outer
membranes 22A and 22B may be sealed together by means of a
heat-sealing device known in the art at regular intervals along
lines 50B, 50C, 50D, and continuously along line 50A.
[0059] A weight 70 may be inserted in compartments 30A and 30B to
ensure that device 102 sinks or is otherwise submerged when placed
in a body of water or an aqueous solution. Weight 70 may be
attached to device 102 by other means. For example, weight 70 may
be attached to or formed as part of membrane shell 22 and/or wick
member 24. The size and shape of the weight 70 may vary depending
on the size of device 102 in general, the intended application and
manufacturing, and packaging concerns. Weight 70 may be formed of a
variety of materials such as stainless steel. It is important for
the particular material used, however, to be inert with respect to
the chemicals in the device. Another method to ensure that device
102 remains submerged in water or an aqueous solution is to place
device 102 inside a weighted holder.
[0060] In order to reduce the chance of a premature exposure of
first dry reactant 40A, second dry reactant 40B, and other
chemicals stored in the compartments 30A and 30B to water or
moisture, sealed outer membranes 22A and 22B and wick member 24 can
optionally be enclosed and sealed in a water-resistant package or
protective outer pouch 105.
[0061] The shape and size of the panels 22A, 22B, and 24 and
corresponding compartments 30A and 30B may vary depending primarily
on the amount of chemicals needed for a particular application.
Methods for calculating dry reactants needed to produce a given
volume and concentrations of a solution having disinfecting
properties are known to those skilled in the art. Additional
factors affecting the size and shape of the panels 22A and 22B and
disinfectant generating device 102 in general include the type of
material used to form the panels, the intended application,
packaging concerns, and material compatibility. The panels 22A and
22B are preferably square or rectangular in shape in order to
facilitate the step of fastening (e.g., sealing) the panels
together.
[0062] Outer membranes 22A and 22B are formed of a material and put
together such that they function as semi-permeable membranes. Outer
membranes 22A and 22B must be permeable to the disinfectant. In one
embodiment, outer membranes 22A and 22B are substantially
impervious (most preferably completely impervious) to liquid (e.g.,
water). Impervious outer membrane 22A and 22B also protect the dry
reactant contents of compartments 30A and 30B so that should small
amounts of water inadvertently enter the sealed outer pouch 105 and
encounter device 102, the impervious membrane shell 22 will not
allow the water to enter compartments 30A or 30B and cause
premature reaction of the reactants therein.
[0063] Wick member 24 also provides a physical barrier to prevent
the contents 40A and 40B of inner compartments 30A and 30B from
mixing together. However, because wick member 24 is hydrophilic,
the reactants may cross this barrier once they are in dissolved
form.
[0064] In use, water or another aqueous solution enters device 102
through the capillary action of the wick member 24 or through the
gaps in the sides of the fastened membrane shell 22 formed by
intermittent fastening (preferably by intermittent heat sealing at
regular intervals along lines 50B, 50C, and 50D at the edges of the
membrane shell 22). The water or solution enters inner compartments
30A and 30B and dissolves the dry reactants 40A and 40B contained
in these spaces. Once in aqueous form, the dissolved reactants 40A
and 40B, contained in inner compartments 30A and 30B, may then
cross the hydrophilic wick member 24 and contact each other. When
the reactants 40A and 40B come into contact, they react and form a
disinfectant. The disinfectant generated in compartments 30A and
30B exits the device through outer membranes 22A and 22B, gaps that
may be present in the fastened sides, and possibly, to some extent,
through the wick member 24.
[0065] Disinfectant generating device 102 provides a small,
enclosed space in which the conversion of this reaction is
enhanced. Outer membranes 22A and 22B are preferably impervious to
water to retain dissolved un-reacted chemical in solution inside
device 102. The pressure required for the disinfectant to exit
compartments 30A and 30B reduces the amount of dissolved,
un-reacted chemicals exiting device 102 before being converted to
disinfectant. However, gaseous disinfectant such as chlorine
dioxide can easily exit the device through the gaps on the sides of
device 102. The small volume of compartments 30A and 30B creates an
environment with high concentrations of both dissolved reactants
40A and 40B, increasing the chance that the two molecules will come
into contact, react, and create the desired disinfectant. Such a
setup is desirable in applications wherein the amount of
disinfectant generated is critical and needs to be precisely
controlled.
[0066] In another embodiment, outer membranes 22A and 22B are
permeable to liquid and gas. In this embodiment, water can enter
the device through outer membranes 22A and 22B and aqueous
disinfectant solution formed in device 102 can exit device 102 by
way of outer membranes 22A and 22B. This decreases the amount of
time required for the desired disinfectant to be generated and is
desirable in applications wherein the level of activation is low
and immediate use of the solution is desired.
[0067] The permeability of outer membranes 22A and 22B with respect
to gas and/or water can be the same or not the same depending on
the desired function of device 102. For example, outer membrane 22A
allows water to pass into one compartment 30A while the outer
membrane 22B does not allow water to pass into the compartment
30B.
[0068] The selected permeability of outer membranes 22A and 22B
with respect to gas and liquid is initially a function of the
material composite and can be modified by mechanically, chemically,
and/or structurally altering the material. For example, as
described below, a plurality of small openings may be formed in one
or both of outer membranes 22A and 22B to facilitate the passage of
liquid into and out of compartments 30A and 30B. Also, one or both
of outer membranes 22A and 22B may be coated with various materials
to alter the permeability thereof.
[0069] Outer membranes 22A and 22B may be constructed of any
membrane material that allows the outer membranes to function as
described above; e.g., that allows the membrane shell to be
substantially impervious to water but permeable to gas. For
example, outer membranes 22A and 22B may be constructed of fibers.
The fibers can be hydrophilic, hydrophobic, or any combination
thereof. The fibers can be naturally occurring and/or synthetic,
and can be woven or non-woven. Additionally, the fibers may be
coated or non-coated. For example, the fibers can be coated to seal
the fibers to each other or to other materials such as in a
laminate composite.
[0070] Suitable synthetic fibers for outer membranes 22A and 22B of
disinfectant generating device 102 may include, but are not limited
to, polyvinyl chloride, polyvinyl fluoride,
polytetrafluoroethylene, polyvinylidene chloride, polyacrylics such
as Orlon.RTM. polyvinyl acetate, polyethylvinyl acetate,
non-soluble or soluble polyvinyl alcohol, polyolefins such as
polyethylene and polypropylene, polyamides such as nylon,
polyesters such as Dacron.RTM. or Kodel.RTM. polyurethanes,
polystyrenes and the like.
[0071] The shape and size of the wick member 24 can vary depending
on the size of the compartments 30A and 30B, the water absorption
rate desired, the type of material used to form the wick member,
the intended application, packaging concerns and material
compatibility. In the preferable embodiment shown in FIGS. 1-7, the
wick member 24 is as wide and extends to the bottom of the
compartment 30, forming two compartments the full length and width
of the membrane shell, 30A and 30B. These features allow the wick
member 24 to absorb and transport a relatively large amount of
water on a relatively rapid basis. In order to increase the surface
area of the wick member 24 to be exposed to the water even further,
for example, the bottom or top ends of the wick member can also
extend beyond the outer edge 40 of the disinfectant generating
device 102. The wick member 24 is sealed to the panels 22A and 22B
around all of its edges, to prevent commingling of the
chemicals.
[0072] In an application where a relatively slow release of
disinfectant is desired, the wick member 24 can be formed of a
material that has a relatively slower wicking rate such that water
is transported more slowly into the compartment 30.
[0073] The wick member 24 can be made out of a large variety of
materials. For example, the wick member can be made of virtually
any material that features capillary action when in contact with
liquid. The wick material thus must be capable of quickly absorbing
water and transporting the absorbed water into the device. For
example, the material used to form the wick member 24 may be made
of synthetic fibers, naturally occurring fiber(s) (both modified
and unmodified) or both. The fibers can include hydrophilic fibers,
hydrophobic fibers or a combination of hydrophilic and hydrophobic
fibers.
[0074] Examples of suitable natural fibers for the wick member 24
include cotton, Esparto grass, bagasse, hemp, flax, silk, wool,
wood pulp, chemically modified wood pulp, jute, rayon, ethyl
cellulose, and cellulose acetate. Suitable synthetic fibers can be
made from polyvinyl chloride, polyvinyl fluoride,
polytetrafluoroethylene, polyvinylidene chloride, polyacrylics such
as Orlon.RTM., polyvinyl acetate, polyethylvinyl acetate,
non-soluble and soluble polyvinyl alcohols, polyolefins such as
polyethylene and polypropylene, polyamides such as nylon,
polyesters such as Dacron.RTM. and Kodel.RTM., polyurethanes,
polystyrenes and the like. Combinations of natural and synthetic
fibers can also be used for the wick member 24, such as
Sontara.RTM.. In order to function as a wick, certain synthetic
fibers may require some modification (e.g., formed into laminates,
etc.). The desired wicking action can result form absorption of
water, capillary action and/or other mechanisms.
[0075] As shown in FIGS. 11 and 12, the inventive system 100 may be
provided with an outer pouch 105 and a disinfectant generating
device 102 further provided with at least one water soluble
membrane 70A, 70B known in the art, may include, but is not limited
to, polyvinyl alcohol, microporous non-woven hydrophobic polymer
sheet materials such as non-woven polyethylene (e.g., Tyvek.RTM.
materials sold by E.I. Du Pont de Nemours & Co.), microporous
non-woven polypropylene materials, expanded polytetrafluoroethylene
(e.g., GoreTex.RTM. sold by W.L. Gore), and kraft paper (e.g.,
X-Crepe-N Grade 4502 sold by Oliver Products Co.), gelatin,
cellulose, and cellulose derivatives such as hydroxypropyl methyl
cellulose.
[0076] Water soluble membrane 70A, 70B may be sealed substantially
continuously to outer membranes 22A, 22B along the edges of the
device 102, for example, using a mechanical heat-sealing process,
to form a third compartment 72A of device 102. Alternatively,
device 102 may additionally be provided with at least two water
soluble membranes 70A, 70B and each of the at least two water
soluble membranes 70A, 70B is sealed substantially continuously to
one of the outer membranes 22A, 22B of the device at the edges to
form a third compartment 72A and a fourth compartment 72B of device
102. The third compartment 72A and the fourth compartment 72B may
each contain at least one inorganic coagulant 304, at least one
polymeric coagulant 310, at least one organic hydrophilic colloid
312, at least one surfactant 80, at least one fragrance material
84, at least one additive 86, or combinations thereof.
[0077] Surfactant 80 of the inventive system 100 is capable of
cleaning or removing soil from a surface or an aqueous solution, as
well as reducing the surface tension of an aqueous solution treated
by the inventive system and having disinfectant properties. A
lowered surface tension would allow an aqueous solution treated by
the inventive system and having disinfectant properties to enter
into cracks or pores of a surface, where dirt particles can
accumulate. Surfactant 80 may include, but is not limited to,
anionic surfactant such as linear alkylbenzene sulfonate, alcohol
ethyoxysulfates, alkyl sulfate, nonionic surfactant such as alcohol
ethoxylate, cationic surfactant such as quaternary ammonium
compounds, amphoteric surfactants such as imidazoline and
betaines.
[0078] Fragrance materials 84 may be in crystalline form and may
include, but are not limited to, linalyl formate and isoamyl
acetate.
[0079] Additives 86 that contribute to the stability of an aqueous
solution treated by the inventive system and having disinfectant
properties may include, but is not limited to, suds stabilizers
such alkylamine oxides, suds suppressors such as alkyl phosphates,
antiredeposition agents such as polycarbonates and polyethylene,
colorants such as pigments and dyes, corrosion inhibitors such as
sodium silicate, opacifiers such as titanium dioxide and polymers,
processing aids such as clays and polymers, sequestrants and
chelating agents such as sodium citrate, complex phosphates, and
EDTA, precipitating agents such as sodium carbonate and sodium
silicate, and ion exchange builders such as zeolites.
[0080] In the embodiments of the inventive system as shown in FIGS.
11 and 12, outer pouch 105 may be provided with disinfectant
generating device 102 having a first dry reactant and a second dry
reactant in powder form 40A, 40B or tablet form 44A, 44B stored in
compartments 30A and 30B of device 102. Powder form or tablet form
of at least one inorganic coagulant 304, at least one polymeric
coagulant 310, at least one organic hydrophilic colloid 312, at
least one surfactant 80, at least one fragrance material 84, at
least one additive 86, or any combinations thereof may be stored
outside of and separated from device 102. Alternatively, powder
form or tablet form of inorganic coagulant 304, polymeric coagulant
310, organic hydrophilic colloid 312, surfactant 80, fragrance
material 84, additive 86, or any combinations thereof may be stored
inside of compartments 72A and 72B of disinfectant generating
device 102. In another alternative, powder form or tablet form of
inorganic coagulant 304, polymeric coagulant 310, organic
hydrophilic colloid 312, or any combinations thereof may be stored
in compartments 30A and 30B and powder form or tablet form of
surfactant 80, fragrance material 84, additive 86, or any
combinations thereof may be stored inside of compartments 72A and
72B or outside of and separated from device 102. In yet another
alternative, powder form or tablet form of inorganic coagulant 304,
polymeric coagulant 310, organic hydrophilic colloid 312, or any
combinations thereof may be stored in compartments 72A and 72B and
powder form or tablet form of surfactant 80, fragrance material 84,
additive 86, or any combinations thereof may be stored outside of
device 102. In still another alternative, any one, two, or
combinations of powder form or tablet form of inorganic coagulant
304, polymeric coagulant 310, or organic hydrophilic colloid 312
may be stored in compartments 30A and 30B, and any one, two, or
combinations of inorganic coagulant 304, polymeric coagulant 310,
and organic hydrophilic colloid 312 in powder form or tablet form,
as well as a combination mixture of surfactant 80, fragrance
material 84, additive 86, or any combinations thereof, in powder
form or tablet form, may be stored outside of device 102 or inside
of compartments 72A and 72B.
[0081] As shown in FIGS. 8-10, inventive system 100 may be provided
with a package comprising a protective outer pouch 105 and at least
one tablet 48 having disinfectant properties being stored within
outer pouch 105. In one embodiment, inventive system 100 may be
provided with an outer pouch 105 including disinfectant tablet 48
that contains at least two dry reactants and at least one inorganic
coagulant 304. In another embodiment, inventive system 100 may be
provided with an outer pouch 105 including disinfectant tablet 48
that contains at least two dry reactants and at least one inorganic
coagulant 304, and additionally at least one polymeric coagulant
310, at least one organic hydrophilic colloid 312, at least one
surfactant 80, at least one fragrance material 84, at least one
additive 86, or any combinations thereof. Alternatively, any one or
any combination of inorganic coagulant 304, polymeric coagulant
310, organic hydrophilic colloid 312, surfactant 80, fragrance
material 84, and additive 86 may be stored in outer pouch 105 in
powder form, separated from tablet 48 that includes at least two
dry reactants. Tablet 48 may be removed from outer pouch 105 and
submerged in water or aqueous solutions upon use for generating a
disinfectant and substantially eliminating impurities in water or
aqueous solutions. Alternatively, the outer pouch may be
constructed of a water soluble material and the entire package may
be submerged in water or aqueous solutions upon use.
[0082] In another embodiment of the inventive system, outer pouch
110 of inventive system 100 may include at least two disinfectant
generating tablets 48 and each tablet 48 contains at least one dry
reactant, as described above, for the production of a disinfectant.
In the alternative, each tablet 48 additionally includes at least
one inorganic coagulant 304. In another alternative, each tablet 48
includes at least one dry reactant and at least one inorganic
coagulant 304, and additionally at least one polymeric coagulant
310, at least one organic hydrophilic colloid 312, at least one
surfactant 80, at least one fragrance material 84, at least one an
additive 86, or combinations thereof.
[0083] In operation, the elements of the inventive system 100 are
immersed in and added into water or an aqueous solution to
disinfect and remove solid impurities from the solution. As
mentioned above, the disinfectant generating device 102 serves to
substantially eliminate microbial contaminants in the solution; the
inorganic coagulant 304 promotes aggregation of the solid
impurities to form flocs; the polymeric coagulant 310 and organic
hydrophilic colloid 312 aid in flocculation and clarification of
the solution; and the surfactant helps the removal of soil from a
solution or a surface and the reduction of surface tension of a
cleaning solution. In general, the greater the molecular weight of
the polymeric coagulant, the greater the flocculating ability. The
longer chain length of the polymeric coagulant allows bridging of
flocs. Hydrophilic colloids have an affinity for water molecules
and can increase the viscosity of an aqueous solution, thereby
improving stability of the solution.
[0084] In the embodiment where the disinfectant generating device
102 or tablet 48, containing first and second reactants, also
contains inorganic coagulant 304, polymeric coagulant 310, organic
hydrophilic colloid 312, surfactant 80, fragrance material 84, or
additive 86, the disinfection and purification process is commenced
by opening outer pouch 105 of system 100 and placing the
disinfectant generating device 102 or tablet 48, including
inorganic coagulant 304, polymeric coagulant 310, organic
hydrophilic colloid 312, surfactant 80, fragrance material 84, or
additive 86, into a vessel, and/or the like, containing a
predetermined volume of water or aqueous solution. Depending on
what volume of water or aqueous solution is to be treated, the
disinfectant generating device is formulated appropriately. For
example, the amount of first and second reactants contained in the
disinfectant generating device 102 is predetermined to achieve a
dose of approximately 1-5 ppm chlorine dioxide in the desired
volume of water, ranging from 1 liter to 3800 liters. The presence
of coagulant in the product, however, means that lower volumes of
water or other aqueous solutions are desirable as the coagulant
needs to be stirred into the water. To promote dispersal of
disinfectant and the coagulant(s), the aqueous solution is stirred
in about 30 seconds intervals for about 30 minutes. The solution is
then allowed to settle for about 30 minutes, after which, the
solution may be decanted and then filtered, utilizing a filtering
device, a towel, or a t-shirt, into clean storage vessels, and the
like.
[0085] In the embodiment where inorganic coagulant 304, polymeric
coagulant 310, organic hydrophilic colloid 312, surfactant 80,
fragrance material 84, or additive 86 is stored independently from
the disinfectant generating device 102 or tablet 48, inorganic
coagulant 304, polymeric coagulant 310, organic hydrophilic colloid
312, surfactant 80, fragrance material 84, or additive 86 is first
added into the vessel of water or aqueous solution. The solution is
stirred in about 30 seconds intervals for about 30 minutes to allow
the formation of flocs. The solution is then allowed to settle for
about 30 minutes, after which, the disinfectant generating device
102 or tablet 48 is placed in the solution. The solution is then
decanted and filtered similar to the above method.
[0086] The inventive system may be used in conjunction with other
devices such as, but are not limited to, a storage container such
as a vessel of appropriate size with clear markings of volume, and
a filtration device.
[0087] In another embodiment of the inventive system, as shown in
FIG. 13, a disinfectant vapor generating device 200 is provided for
producing vapor having disinfectant properties when exposed to
ambient moisture. Device 200 is capable of producing disinfecting
vapor via a time release manner. In other words, the production of
disinfecting vapor may be slow released over a relatively long
period of time (weeks to months), or an accelerated release may be
provided depending on the construction of the device and
arrangement of components. Over time, the release of disinfecting
vapor reaches the maximum amount released and then the release
levels off and eventually decreases to zero.
[0088] Device 200 is provided with an inner membrane that defines
and separates a first and a second compartment. These compartments
house one or more dry reactants capable of producing disinfecting
vapor when the reactants are exposed to ambient moisture. At least
two compartments are provided, each having an outer membrane
defining walls of the device 200. The outer membrane is moisture
and gas permeable; and it is impermeable to liquid water and
reactant powders. The inner membrane may be sealed to the outer
membranes continuously or non-continuously along the edges of the
device 200.
[0089] The production of disinfecting vapor via the device 200 is a
clear function of relative humidity. The device 200 generates
higher amounts of disinfecting vapor at a higher rate of generation
when it is placed in an environment with high humidity. In an
environment with low humidity, the device 200 produces less
disinfecting vapor at a lower rate of generation.
[0090] The inner membrane of the device 200 is capable of absorbing
and transporting small amounts of partially dissolved reactant
across the membrane to the compartment containing the other
reactant. The inner membrane also serves to facilitate the transfer
of moisture from one compartment to the other. The structure of
this inner membrane has unique physical properties. The inner
membrane has a high absorbent capacity and absorbency rate in
water, oil, and solvents. The inner membrane is preferably
hydrophilic, capable of transmitting air or gases (e.g. Frazier
porosity >10 ft.sup.3/ft.sup.2 min). The inner membrane is
preferably also ultra strong, durable, abrasion resistant (e.g.
able to withstand tensile strength of 15-30 lbs) and chemically
resistant. It is important that the inner membrane is chemically
resistant in dry and/or wet conditions in the presence of acidic
and/or oxidizing environments, so that the membrane is not degraded
or ruptured during placement or operation. The inner membrane is
generally made of non-woven materials, preferably made of material
generated from a spun lacing process (e.g. hydro entangling
process). Materials produced from this process have high absorbent
capacities and absorbency rates in water, oil, and solvents. In
addition, the materials are ultra strong, durable, and abrasion
resistant.
[0091] In one embodiment of device 200, the outer membranes and the
inner membrane are sealed together continuously along four edges of
the device, forming a pouch with a first inner compartment and a
second inner compartment. The compartments are provided with dry
reactant components capable of producing disinfectant vapor when
the reactants react with ambient moisture. The compartments may
optionally be provided with additives 86 such as fragrance
materials, catalyst, adhesive, thickeners, penetrating agents,
stabilizers, surfactants, binders, organic solids, inorganic
solids, catalysts, desiccants, deliquescent materials such as
potassium sulphate, calcium sulphate, ammonium sulphate, anhydrous
sodium sulfate, sodium phosphate, magnesium nitrate, calcium
nitrate, magnesium acetate, barium chloride, magnesium chloride,
aluminum chloride, calcium chloride, lithium chloride, sodium
chloride, potassium chloride, ammonium chloride, potassium bromide,
potassium carbonate, sodium carbonate, sodium nitrite, and mixtures
thereof.
[0092] Deliquescent materials have a strong affinity for moisture
and can be used to facilitate transfer of moisture into device 200.
For example; in addition to the first and second dry reactant, the
first compartment, the second compartment, or the first and second
compartments of device 200 may be provided with a deliquescent
material, as described above, to facilitate the transfer of
moisture into device 200 for the production of a disinfectant
vapor.
[0093] When the device 200 is exposed to the environment, the
moisture in the air naturally penetrates the two outer membranes.
As the moisture reaches the compartment, and the reactants become
hydrated and slowly become partially dissolved adjacent to the
inner membrane. The partially dissolved reactants then come in
contact with each other via the inner membrane to produce a
disinfectant vapor. Eventually, the generated disinfectant vapor
slowly diffuses out of the outer membranes into the surrounding
environment.
[0094] The outer membranes of device 200 may be constructed from
any membrane material that allows the membranes to function as a
physical barrier that separate the dry reactants from the
environment but are permeable to ambient moisture. The outer
membranes are substantially impervious to water and reactant
powders but permeable to ambient moisture and disinfectant vapor.
The outer membrane materials may be naturally occurring, synthetic,
woven, non-woven, or hydrophobic. Additionally, the materials may
be coated or non-coated, and may be multi-layered. It is important
that the outer membrane has a small mean flow pore size and bubble
point (e.g. <10 microns) and low water permeability, so that it
is impervious to water while allowing moisture, air and gases to
pass through (e.g., Gurley Hill Porosity of 22 seconds/100 cc). In
addition, the outer membrane preferably has high tensile strength
and pressure, and is chemically resistant. Some examples of
suitable synthetic materials for the outer membranes may include,
but are not limited to: polyvinyl chloride, polyvinyl fluoride,
polyvinylidene chloride, polytetrafluoroethylene, polyacrylics such
as Orlon.RTM., polyvinyl acetate, polyethylvinyl acetate,
non-soluble or soluble polyvinyl alcohol, polyolefins such as
polyethylene and polypropylene, polyamides such as nylon,
polyesters such as Dacron.RTM. or Kodel.RTM., polyurethanes,
polystyrenes, and the like. The outer membranes may also be
constructed from: micro porous non-woven polyethylene polymer sheet
materials (e.g., Tyvek.RTM. brand material sold by Dupont), micro
porous non-woven polypropylene materials, expanded
polytetrafluoroethylene (e.g., Gore-Tex.RTM. brand sold by W. L.
Gore), and Kraft paper (e.g., X-Crepe-N Grade 4502 sold by Oliver
Products Co.), and the like.
[0095] The material of the inner membrane may comprise hydrophilic
materials or a combination of hydrophilic and hydrophobic materials
that exhibit hydrophilic properties. For example, the inner
membrane may be constructed from virtually any material is capable
of absorbing moisture/water and transporting the absorbed
moisture/water from one compartment to another. Examples of
suitable natural materials for the inner membrane include, but are
not limited to: cotton, Esparto grass, bagasse, hemp, flax, silk,
wool, wood pulp, reactantly modified wood pulp, jute, rayon, ethyl
cellulose, and cellulose acetate, and the like. Suitable synthetic
materials for the inner membrane may include, but are not limited
to: polyvinyl chloride, polyvinyl fluoride,
polytetrafluoroethylene, polyvinylidene chloride, polyacrylics such
as Orlon.RTM., polyvinyl acetate, polyethylvinyl acetate,
non-soluble and soluble polyvinyl alcohol, polyolefins such as
polyethylene and polypropylene, polyamides such as nylon,
polyesters such as Dacron.RTM. or Kodel.RTM., polyurethanes,
polystyrenes, and the like. In addition, the materials may be made
of the combination of natural materials and synthetic materials
that are derived from non-woven technologies. One preferred process
for producing non-woven materials is a spun lacing process (hydro
entangling process). Materials produced by this process contain no
binders or glues, are low-linting, have high texture-like and high
absorbent capacity and absorbency rates in water, oil and solvents.
In addition, they are ultra strong, durable, and abrasion
resistant. Examples of these materials are Sontara.RTM.
engineered-cloth wipers produced by Dupont.RTM. (Sontara.RTM.
AC.TM., Sontara.RTM. SPS.TM., Sontara.RTM. FS.TM., Sontara.RTM.
EC.TM., Sontara.RTM.ERC.TM., Sontara.RTM. PC.TM.).
[0096] In another embodiment of device 200, as shown in FIG. 13,
the two outer membranes and inner membrane may be mechanically
heat-sealed together non-continuously along three edges of the
device 200 to form a pouch with a plurality of small openings 240
distributed around the three edges for facilitating moisture into
the device 200. Along one edge of the device 200, the membranes are
sealed together continuously, without the small openings 240. As
shown in FIG. 13, area 220 is the area where the membranes are
mechanically heat-sealed together; whereas, area 240 is the area
where the membranes are not mechanically heat-sealed together, but
rather, the membranes are mechanically compressed. The small
openings 240 are sealed in a way such that the dry reactant
components can remain inside of the device 200. These small
openings 240 increase the moisture transfer rate into the device
200, the reactants' dissolution rate, the disinfectant generation
rate, and the facilitation rate of disinfectant vapor out of the
device 200. Device 200 may be designed in such a way that the
number of small openings on the edges of the device may vary,
depending on the desired disinfectant vapor production rate.
[0097] In the embodiment as shown in FIG. 13, when the inner
membrane of device 200 is constructed from materials capable of
absorbing water and moisture, the device 200 is capable of
transporting water into the device 200 through the wicking effect
of the inner membrane. The transportation of a small amount of
water into the device 200 through compressed areas 240 on the edges
of the device 200 significantly shortens the time required for
disinfectant vapor to be produced, which may function as a device
for fast-release of disinfectant vapor.
[0098] First and second dry reactants utilized in connection with
the inventive system may be in any dry physical form. Examples of
the dry physical form include, but are not limited to: powders,
granules, pellets, tablets, agglomerates, and the like. Preferably,
the components are in powder form because powders have a larger
surface area, and tend to dissolve in water and react more quickly
when compared to large particles, such as pellets or
agglomerates.
[0099] First dry reactant 40A and second dry reactant 40B capable
of producing a disinfectant upon exposure to water or moisture may
be a metal chlorite component and an acid component. As the water
or moisture is wicked into the membrane shell through capillary
action and reaches, for example, the metal chlorite component 40A
and acid component 40B, the components 40A and 40B become hydrated
and slowly become partially dissolved adjacent in compartments 30A
and 30B, adjacent to the wick member 24. The partially dissolved
reactants 40A and 40B then can cross the hydrophilic wick membrane
24 and contact each other to produce chlorine dioxide inside the
pouch by the following reactant reaction:
5ClO.sub.2.sup.-+5H.sup.+.fwdarw.4ClO.sub.2+HCl+2H.sub.2O.
Eventually, the generated chlorine dioxide slowly diffuses out of
the membrane shell 22 into the surrounding environment.
[0100] For the production of chlorine dioxide, the metal chlorite
component may comprise sodium chlorite, particularly dry technical
grade sodium chlorite (containing about 80% by weight sodium
chlorite and 20% by weight of sodium chloride, sodium chlorate and
others), calcium chlorite, potassium chlorite, barium chlorite,
magnesium chlorite, alkali metal chlorites, alkaline earth metal
chlorites, and mixtures thereof.
[0101] Generally, a dry solid hydrophilic acid component is
employed, which does not substantially react with the metal
chlorite component until the reactants are partially dissolved and
come in contact by crossing through hydrophilic wick member 24.
Examples of acid components that may be used in the production of
chlorine dioxide include, but are not limited to, sodium
bisulphate, citric acid, mandelic acid, boric acid, lactic acid,
tartaric acid, maleic acid, malic acid, glutaric acid, adipic acid,
acetic acid, formic acid, sulfamic acid, sulfuric acid,
hydrochloric acid, phosphoric acid, phosphoric anhydride, sulfuric
anhydride, water soluble organic acid anhydrides, such as maleic
anhydride, and water soluble acid salts, such as calcium chloride,
magnesium chloride, magnesium nitrate, lithium chloride, magnesium
sulfate, aluminum sulfate, sodium acid sulfate, sodium dihydrogen
phosphate, potassium acid sulfate, potassium dihydrogen phosphate,
and mixtures thereof.
[0102] When disinfectant generating device 102 contains sodium
chlorite as a metal chlorite component and sodium persulfate as
second dry reactant, the device 102, upon exposure to water or
moisture, is capable of producing chlorine dioxide via oxidation of
sodium chlorite by sodium persulfate by the following reaction:
2NaClO.sub.2+Na.sub.2S.sub.2O.sub.8.fwdarw.2ClO.sub.2+2Na.sub.2SO.sub.4.
[0103] When disinfectant generating device 102 contains sodium
chlorite as a metal chlorite component and a chlorine releasing
compound as a acid component, the device 102, upon exposure to
water or moisture, is capable of producing chlorine dioxide via
oxidation of the sodium chlorite by the chlorine releasing
compounds by, for example, the following reaction:
2NaClO.sub.2+NaOCl+HCl.fwdarw.2ClO.sub.2+2 NaCl+NaOH.
[0104] When disinfectant generating device 102 contains sodium
chlorate as a metal chlorite component and oxalic acid as a acid
component, the device 102, upon to exposure to water, is capable of
producing chlorine dioxide via reduction of the sodium chlorate by
the oxalic acid by the following reaction:
2NaClO.sub.3+H.sub.2C.sub.2O.sub.4.fwdarw.2ClO.sub.2+2CO.sub.2+2H.sub.2O.
[0105] In addition to chlorine dioxide, the inventive device 102
may be employed to produce other disinfectants upon exposure to
water or moisture. For example, peracetic acid may be produced by
the device 102 when first and second dry reactants 40A and 40B, are
tetraacetylethylenediamine (TAED) and peroxygen compounds.
Peroxygen compounds release hydrogen peroxide, which reacts with
TAED to produce peracetic acid and diacetylethylenediamine (DAED)
as follows: TAED+2H.sub.2O.sub.2.fwdarw.2CH.sub.3COOH+DAED. Both
TAED and DAED are non-toxic and non-sensitizing, and are readily
biodegraded in the environment. Examples of peroxygen compounds
include, but are not limited to, sodium percarbonate, sodium
perborate, and urea hydrogen peroxide.
[0106] Bromine may also be produced by the device 102 when first
and second dry reactants 40A and 40B are a sodium bromide and a
potassium monopersulfate compound. The bromine is produced via the
oxidation of sodium bromide by potassium monopersulfate compounds
as follows: NaBr+Potassium monopersulfate.fwdarw.Hypobromous
acid.
[0107] Sulfur dioxide may be produced by the device 102 when first
and second dry reactants 40A and 40B are a sodium bisulfite and an
acid component. The sulfur dioxide is produced via the activation
of sodium bisulfite with the acid:
NaHSO.sub.3+H.sup.+.fwdarw.SO.sub.2+Na.sup.++H.sub.2O. Examples of
the acid component include, but are not limited to, citric acid and
fumaric acid.
[0108] Carbon dioxide may be produced by the device 102 when first
and second dry reactants 40A and 40B are sodium carbonate and an
acid component. The carbon dioxide is produced via the activation
of sodium carbonate with the acid:
CaCO.sub.3+2H.sup.+.fwdarw.CO.sub.2+H.sub.2O+Ca.sup.+. The acid
component may be, for example, citric acid.
[0109] Further, the reactants 40A and 40B may each be impregnated
on inert carriers that are reactantly compatible with the reactants
40A and 40B. The coagulants, colloids, surfactants, fragrance
materials, and additives also may be impregnated on inert carriers.
A carrier is useful to control the release of the reactants 40A and
40B, and thus the reaction may be further controlled. Examples
include, but are not limited to: zeolite, kaolin, mica, bentonite,
sepiolite, diatomaceous earth synthetic silica, and the like.
[0110] The following example is provided to further illustrate the
effectiveness of the disinfectant generating device of present
invention.
EXAMPLE 1
[0111] Two layers of a microporous, hydrophobic non-woven
polyethylene sheet material (Tyvek.RTM. sold by E.I. Du Pont de
Nemours & Co.--type 1073B) was intermittently heat sealed to a
hydrophilic material consisting of non-woven natural and synthetic
fibers (Sontara.RTM. sold by Dupont). The Sontara.RTM. was placed
between the two layers of Tyvek.RTM. and the bottom and sides were
sealed forming a pouch divided in two, creating two compartments.
The pouch measured 2.5 inches by 2.5 inches. One compartment of the
pouch was filled with 0.4 g technical grade sodium chlorite of 80%
purity and the other compartment was filled with 0.4 g sodium
bisulfate. The pouch was placed in 5 gallons of tap water at
20.degree. C. The absorbance of the solution was measured with a
spectrophotometer at a wavelength of 360 nm and then converted to
an mg/l concentration of chlorine dioxide. TABLE-US-00001 TABLE 1
Time Concentration 0 min. 0 mg/l 15 min. 2.5 mg/l 30 min. 3.5 mg/l
45 min. 3.8 mg/l 60 min. 3.8 mg/l
This final concentration of 3.8 mg/l is near the upper bound of
chlorine dioxide required to disinfect unclean water. Municipal
water treatment plants typically use between 1 and 2.5 ppm chlorine
dioxide for disinfection, usually after a clarification and
sedimentation process. By changing the masses of the reactants used
to manufacture the pouch, the concentration of chlorine dioxide
produced in this volume of water can easily be decreased or
increased as necessary.
[0112] It will be understood that the foregoing descriptions of
various embodiments of systems and methods for the present
invention are merely illustrative of the invention and its varied
embodiments. Modifications to various aspects of the systems and
methods of the present invention will be apparent to hose skilled
in the art and are intended to fall within the scope and purview of
this disclosure and the following claims.
* * * * *