U.S. patent application number 17/132920 was filed with the patent office on 2021-04-22 for ammonia abatement for animal litter.
This patent application is currently assigned to Chemtrade Chemicals US LLC. The applicant listed for this patent is Chemtrade Chemicals US LLC. Invention is credited to Rex A. Johns.
Application Number | 20210112771 17/132920 |
Document ID | / |
Family ID | 1000005505151 |
Filed Date | 2021-04-22 |
United States Patent
Application |
20210112771 |
Kind Code |
A1 |
Johns; Rex A. |
April 22, 2021 |
AMMONIA ABATEMENT FOR ANIMAL LITTER
Abstract
A method for preparing an ammonia abatement additive for poultry
litter that is formulated to assure activation in an interior
environment having various relative humidity conditions. The method
includes obtaining a blended litter amendment composition that,
based on weight, is about 40% deliquescent salt and about 60%
aluminum sulfate, relative to a total weight of the two components.
The composition can be made by the user or received, already
blended, from a third party. To this blended composition that has
been obtained, additional deliquescent salt is added in an amount
such that the total amount of deliquescent salt is effective to
activate the alum-containing ammonia abatement additive at the
targeted low relative humidity condition in the interior of a
poultry house. The composition is a sub-component of the ammonia
abatement additive which may or may not contain additional
compounds. The specified relative proportions (i.e., 40%
deliquescent salt and 60% alum) only consider the proportion of
deliquescent salt and the proportion of alum relative to the sum of
the two components, based on weight. If there are other, extraneous
compounds included in the ammonia abatement additive, those
extraneous compounds are not counted in the defined and claimed
proportions.
Inventors: |
Johns; Rex A.; (Jonesboro,
AR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Chemtrade Chemicals US LLC |
Parsippany |
NJ |
US |
|
|
Assignee: |
Chemtrade Chemicals US LLC
Parsippany
NJ
|
Family ID: |
1000005505151 |
Appl. No.: |
17/132920 |
Filed: |
December 23, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15931376 |
May 13, 2020 |
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17132920 |
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62972559 |
Feb 10, 2020 |
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63115915 |
Nov 19, 2020 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A01K 1/0155 20130101;
A01K 2227/30 20130101; A01K 1/0154 20130101 |
International
Class: |
A01K 1/015 20060101
A01K001/015 |
Claims
1. A method for preparing an ammonia abatement additive for poultry
litter that is formulated to activate in a targeted low relative
humidity interior environment, the method comprising: obtaining a
blended litter amendment composition, said composition comprising,
based on weight, about 40% deliquescent salt and about 60% aluminum
sulfate; and adding an amount of additional deliquescent salt,
wherein the total amount of deliquescent salt is effective to
activate the ammonia abatement additive at a targeted low relative
humidity condition in an interior environment.
2. The method as recited in claim 1 wherein the amount of
additional deliquescent salt is sufficient to bring a resulting
adjusted litter amendment composition to about 60% deliquescent
salt compared to about 40% aluminum sulfate; and wherein the
resulting adjusted litter amendment composition of about 60%
deliquescent salt compared to about 40% aluminum sulfate
constitutes an ammonia abatement additive for poultry litter
corresponding to a targeted low relative humidity interior
environment having about 45% or less relative humidity.
3. The method as recited in claim 2 further comprising applying the
adjusted litter amendment composition to poultry litter that has
been determined to have a moisture content corresponding to an
interior environment having about 45% relative humidity.
4. The method as recited in claim 1 wherein the amount of
additional deliquescent salt is sufficient to bring a resulting
adjusted litter amendment composition to about 70% deliquescent
salt compared to about 30% aluminum sulfate; and wherein the
resulting adjusted litter amendment composition of about 70%
deliquescent salt compared to about 30% aluminum sulfate
constitutes an ammonia abatement additive for poultry litter
corresponding to a targeted low relative humidity interior
environment having about 40% or less relative humidity.
5. The method as recited in claim 4 further comprising applying the
adjusted litter amendment composition to poultry litter that has
been determined to have a moisture content corresponding to an
interior environment having about 40% relative humidity.
6. The method as recited in claim 1 wherein the amount of
additional deliquescent salt is sufficient to bring a resulting
adjusted litter amendment composition to about 80% deliquescent
salt compared to about 20% aluminum sulfate; and wherein the
resulting adjusted litter amendment composition of about 80%
deliquescent salt compared to about 20% aluminum sulfate
constitutes an ammonia abatement additive for poultry litter
corresponding to a targeted low relative humidity interior
environment having about 35% or less relative humidity.
7. The method as recited in claim 6 further comprising applying the
adjusted litter amendment composition to poultry litter that has
been determined to have a moisture content corresponding to an
interior environment having about 35% relative humidity.
8. The method as recited in claim 1 wherein the amount of added
deliquescent salt is sufficient to bring a resulting adjusted
litter amendment composition to about 90% deliquescent salt
compared to about 10% aluminum sulfate; wherein the resulting
adjusted litter amendment composition of about 90% deliquescent
salt compared to about 10% aluminum sulfate constitutes an ammonia
abatement additive for poultry litter corresponding to a targeted
low relative humidity interior environment having about 30% or less
relative humidity.
9. The method as recited in claim 8 further comprising applying the
adjusted litter amendment composition to poultry litter that has
been determined to have a moisture content corresponding to an
interior environment having about 30% relative humidity.
10. The method as recited in claim 1 wherein the amount of added
deliquescent salt is sufficient to bring a resulting adjusted
litter amendment composition to about 50% deliquescent salt
compared to about 50% aluminum sulfate; and wherein the resulting
adjusted litter amendment composition of about 50% deliquescent
salt compared to about 50% aluminum sulfate constitutes an ammonia
abatement additive for poultry litter corresponding to a targeted
low relative humidity interior environment having about 50% or less
relative humidity.
11. The method as recited in claim 10 further comprising applying
the adjusted litter amendment composition to poultry litter that
has been determined to have a moisture content corresponding to an
interior environment having about 50% relative humidity.
12. A method for providing an ammonia abatement additive for
poultry litter that is formulated to activate prior to the
introduction of poultry onto the litter, the method comprising:
providing an amount of deliquescent salt having a first weight; and
providing an amount of aluminum sulfate having a second weight,
wherein the amount of aluminum sulfate is about one and one-half
times the amount of deliquescent salt, based on weight.
13. The method as recited in claim 12 wherein the ammonia abatement
additive for poultry litter is formulated to activate in average US
relative humidity and wherein average US relative humidity is about
60% relative humidity.
14. The method as recited in claim 13 further comprising applying
the adjusted litter amendment composition to poultry litter that
has been determined to have a moisture content corresponding to an
interior environment having about 60% relative humidity.
15. The method as recited in claim 12 further comprising: providing
additional aluminum sulfate in an amount approximately equal to
twice the amount of already-provided deliquescent salt, based on
weight and wherein the additional amount of aluminum sulfate is
provided in correspondence with a use-environment of greater than
70% relative humidity.
16. The method as recited in claim 15 further comprising applying
the adjusted litter amendment composition to poultry litter that
has been determined to have a moisture content corresponding to an
interior environment having about 70% relative humidity.
17. The method as recited in claim 12 further comprising: providing
additional aluminum sulfate in an amount approximately equal to
three times the amount of already-provided deliquescent salt, based
on weight and wherein the additional amount of aluminum sulfate is
provided in correspondence with a use-environment of greater than
80% relative humidity.
18. The method as recited in claim 17 further comprising applying
the adjusted litter amendment composition to poultry litter that
has been determined to have a moisture content corresponding to an
interior environment having about 80% relative humidity.
19. The method as recited in claim 12 further comprising: providing
additional aluminum sulfate in an amount approximately equal to
four times the amount of already-provided deliquescent salt, based
on weight.
20. The method as recited in claim 19 wherein the additional amount
of aluminum sulfate is provided in correspondence with a
use-environment of greater than 90% relative humidity.
Description
FIELD
[0001] The presently disclosed technology relates to improvements
in the treatment of animal litter using aluminum sulfate ("alum")
to reduce the generation of ammonia from animal waste in the
litter. More particularly, the technology relates to the
combination of a deliquescent salt with the alum to increase the
presence of water in the alum and activate its ammonia abatement
capabilities. In a more specific example, the technology relates to
compositions and methods for adapting poultry litter located in a
poultry house.
DETAILED DESCRIPTION
[0002] Within certain animal enclosures, and especially within
poultry houses, high amounts of ammonia are generated that
negatively affect the resident animals. The adverse effects can
include such things as diminished weight gain and increased
mortality among the housed animals, and especially in young chicks.
To improve animal comfort and wellbeing, litter having various
components is put down ahead of the animals' introduction to the
space, and that initial installation of litter is typically
maintained throughout their stay. To treat the litter and better
alleviate the negative effects of waste-generated ammonia in the
enclosure, an ammonia abatement additive is applied to the litter.
According to the teachings of the presently disclosed technology,
the additive includes a deliquescent salt, such as calcium
chloride, blended with the alum in particular discovered and
advantageous proportions, in dependence upon the measured or
expected relative humidity of the intended eventual
use-environment.
[0003] The alum is the compound that, when activated, neutralizes
ammonia. Proper activation of the alum, however, is dependent upon
sufficient moisture being present in the alum to induce its pH
reducing functionality that neutralizes the offending ammonia. To
gain the necessary moisture content in the alum, deliquescent salt
is incorporated. Deliquescent salts, by definition, are
sufficiently hydrophilic that they have a capacity to absorb enough
moisture out of atmospheric air to liquefy themselves. The presence
of the deliquescent salt initiates hydrolysis and increases the
moisture level in the alum. A surprising discovery of the present
technology is that the proportional amounts of deliquescent salt to
alum correlate to expected relative humidities within an animal
enclosure.
[0004] In the case of poultry houses, recent design features
intended to increase the comfort and wellbeing of the birds have
actually compromised the activation capabilities of the alum in the
litter to abate ammonia produced by the birds' waste. A specific
example is the use of "tunnel ventilation" and other enhanced air
circulation methods in new poultry houses intended to cool the
birds and better draw in fresh air. An unintended, but discovered
consequence of this increased air circulation is an over-drying of
the litter. By this applicant's research, this effect has been
discovered to uniquely track the relative humidity outside the
poultry house, which in turn effects the relative humidity inside
the poultry house. As a result, customized blending of deliquescent
salt and alum has been invented and is described and claimed
herein.
[0005] Another situation that has been detected in modern poultry
house constructions is over-wetting of freshly applied poultry
litter under certain conditions and/or circumstances. The
absorption of too much water by animal litter can have a
detrimental effect because wet litter tends to reduce animal weight
gain performance and provides a hospitable environment for
pathogens. Wet litter also enhances the presence of pathogen
vectors and attracts destructive insects such as flies and beetles
that disturb the animals and reduce feed conversion to weight
gain.
[0006] One such overly damp situation occurs when the slab of the
poultry house is cold enough to condense moisture out of the air,
wetting the surface of the concrete, and in turn, wetting litter
deposited thereupon. In this regard, the amount of surface wetness
correlates to the degree of relative humidity inside the poultry
house. The same effect, but occurring by a different modality, is
slab "weeping" of water up through the concrete from the ground
below. Both situations (condensate and weeping) result in overly
moist or wet litter that hampers the ability of applied alum to
neutralize ammonia. To combat these effects on the alum, based on
this applicant's research, unique blends of deliquescent salt in
proportion to alum have been discovered and are described and
claimed herein. Among other aspects, the alum content of the litter
additive is increased, in correlation with the expected amount of
excess moisture, thereby potentiating the alum's ammonia
neutralizing capabilities.
[0007] The optimal moisture content of animal litter is generally
assumed to be from about 25% to about 30%. The actual moisture
content (MC) of animal litter can be determined as follows:
MC=[(W.sub.o-W.sub.d)/W.sub.o].times.100
wherein W.sub.o is wet litter weight and W.sub.d is dry litter
weight. Animal litter having a moisture content from about 30% to
about 35% is termed high moisture litter, and animal litter having
a moisture content of about 35% or greater is termed wet litter.
Excess moisture in the litter is associated with increased
microbial activity in the litter, increased ammonia emissions,
increased odor emissions, increased contact dermatitis in the
animals, and may negatively affect the feed conversion ratio and
carcass yields.
[0008] Animal litter having a moisture content from about 20% to
about 25% is termed low moisture litter, and animal litter having a
moisture content of about 20% or less is termed dry litter. Low
moisture levels in the litter can be associated with respiratory
diseases, dehydration of young animals, and/or reduced air quality
in the animal facility.
[0009] Another measure of moisture in litter is water activity
(A.sub.w), which is a thermodynamic property that has been shown to
be more closely related to microbial, chemical and physical
properties of natural products than moisture content. A.sub.w
relates to the relative freedom or availability of water in a
sample and its tendency to escape. A.sub.w is defined as the ratio
of the fugacity of water in a system, and the fugacity of pure
liquid water at the same temperature, where fugacity is a measure
of the escaping tendency of a substance. A.sub.w provides a measure
of the thermodynamic forces driving the movement of water within
and between media (including air). Water will migrate from higher
A.sub.w to lower A.sub.w until equilibrium is achieved and A.sub.w
is constant throughout the system (assuming isothermal conditions).
A.sub.w has been shown to be related to physical handling
properties of litter including cohesion, adhesion, compressibility
and flowability. Further, it was been shown that maintaining litter
below a critical A.sub.w value (e.g., less than about 0.84)
corresponds with reduced growth of pathogens such as Salmonella and
Escherichia coli.
[0010] Regarding the compositional blends and blending of the
deliquescent salt and alum, it is contemplated that the specially
designed mixtures of the two components can be mixed together
before application to the litter or individually (sequentially or
simultaneously) added to the litter. Regardless, the components are
ultimately in combination on the target media, such as animal
litter.
[0011] Suitable litter compositions or media can include mixtures
comprising (meaning includes, but is not limited to) one or more of
wood shavings, secondary paper, nut hulls, bran hulls, rice hulls,
wood chips, sand and sawdust as examples. Further examples are
particle board residue, wheat chips, bean straw, oat straw, wheat
straw, hay, corn cobs, corn stover, soybean residue, soybean
stubble, rice straw, bean straw, miscanthus grass, switch grass,
Indian grass, big bluestem grass, prairie grasses, oat hulls, rice
hulls, nut hulls, peanut hulls, sugar cane pulp, kenaf core, kenaf
residue, feathers, peat moss, shredded paper, recycled paper,
recycled cardboard, sand, composted municipal garbage, dried
compost, or combinations of any of the above. Other materials are
known to those skilled in the art.
[0012] Suitable deliquescent materials include chlorides such as
magnesium chloride, calcium chloride, manganese chloride, ferric
chloride and zinc chloride; and other metal salts including
ammonium citrate, calcium chlorate, calcium iodide, calcium
nitrite, calcium nitrate, cobaltous ammonium chloride, cobaltous
iodide, cupric chlorate, cupric nitrate, ferric chloride, ferric
lactate, ferric nitrate, ferrous iodide, magnesium ammonium
chloride, magnesium nitrate, magnesium nitrite, manganese oxide,
manganese sulfate, phosphoric acid, phosphorus oxide, potassium
acetate, potassium carbonate, potassium iodide, potassium
phosphate, sodium bisulfate, sodium acetate, stannic sulfate and
zinc chloride.
[0013] Deliquescent salts including calcium chloride, magnesium
chloride, sodium bisulfate, manganese chloride, zinc chloride,
anhydrous ferric chloride, magnesium nitrate, calcium nitrate,
potassium acetate and sodium acetate, are preferred. Since some of
these deliquescent salts may have adverse effects on some animals,
such as poultry chicks, the types of the salts must be carefully
selected. The addition of the deliquescent material is also
regarded as aiding control of nuisance dust in the animal housing.
Calcium chloride, being a very effective deliquescent material,
absorbs moisture from the atmosphere, even very dry atmospheres,
until a solution is formed; this absorbed water becomes the
activator for alum.
[0014] The following are example embodiments that are within the
scope of this disclosure. Other, different and/or broader
embodiments are also within the scope of this disclosure, some of
which can include elements of one example embodiment combined with
elements of another example embodiment (to the extent combinable),
or subsets of elements of one or another specific example
embodiment.
[0015] In a first characterization, the presently disclosed
technology takes the form of a method for preparing an ammonia
abatement additive for poultry litter that is formulated to assure
activation in an interior environment having a low relative
humidity which is being targeted for ammonia abatement activation.
That is to say, a poultry house will be located in a climate and
location having ambient (outdoor) characteristics that influence
the conditions of the house's interior environment, but they will
not necessarily be identical. Because it is within the interior
environment that the animals are actually raised, the present
technology is concerned with the relative humidity of that interior
space, and in particular, the interior space of a poultry house in
which the relative humidity prior to the birds' occupation is low,
and that degree of relative humidity is considered "targeted"
because it is the relative humidity under which the ammonia
abatement additive will desirably perform.
[0016] As represented in FIG. 1, the presently described technology
comprises obtaining a blended litter amendment composition that,
based on weight, is about 40% deliquescent salt and about 60%
aluminum sulfate, relative to a total weight of the two components.
The composition is characterized as being "obtained" because it is
contemplated that the blended composition may be made by the user
or received, already blended, from a third party. To this blended
composition that has been obtained, additional deliquescent salt is
added in an amount such that the total amount of deliquescent salt
is effective to activate the alum-containing ammonia abatement
additive at the targeted low relative humidity condition in the
interior of a poultry house. The "composition" is a sub-component
of the "ammonia abatement additive" which may or may not contain
additional compounds. The specified relative proportions (i.e., 40%
deliquescent salt and 60% alum) only consider the proportion of
deliquescent salt and the proportion of alum relative to the sum of
the two components, based on weight. If there are other, extraneous
compounds included in the ammonia abatement additive, those
extraneous compounds are not counted in the defined and claimed
proportions.
[0017] In one example, the amount of additional deliquescent salt
is sufficient to bring a resulting adjusted litter amendment
composition to about 60% deliquescent salt compared to about 40%
aluminum sulfate. In this instance, the resulting adjusted litter
amendment composition corresponds to a targeted low relative
humidity interior environment having about 45% or less relative
humidity.
[0018] Thereafter, the adjusted litter amendment composition is
applied to poultry litter that has been determined to have a
moisture content corresponding to an interior environment having
about 45% relative humidity. To obtain such correspondence, the
relative humidity of the interior environment of the poultry house
is measured. As an example, a capacitive humidity sensor can be
employed to measure the interior relative humidity and which does
so utilizing a thin strip of metal oxide between two electrodes and
the metal oxide's electrical capacity changes indicate the
atmosphere's relative humidity.
[0019] In another example, the amount of additional deliquescent
salt is sufficient to bring a resulting adjusted litter amendment
composition to about 70% deliquescent salt compared to about 30%
aluminum sulfate. In this instance, the resulting adjusted litter
amendment composition corresponds to a targeted low relative
humidity interior environment having about 40% or less relative
humidity.
[0020] In yet another example, the amount of additional
deliquescent salt is sufficient to bring a resulting adjusted
litter amendment composition to about 80% deliquescent salt
compared to about 20% aluminum sulfate. In this instance, the
resulting adjusted litter amendment composition corresponds to a
targeted low relative humidity interior environment having about
35% or less relative humidity.
[0021] In still another example, the amount of additional
deliquescent salt is sufficient to bring a resulting adjusted
litter amendment composition to about 90% deliquescent salt
compared to about 10% aluminum sulfate. In this instance, the
resulting adjusted litter amendment composition corresponds to a
targeted low relative humidity interior environment having about
30% or less relative humidity.
[0022] In yet, still another example, the amount of additional
deliquescent salt is sufficient to bring a resulting adjusted
litter amendment composition to about 50% deliquescent salt
compared to about 50% aluminum sulfate. In this instance, the
resulting adjusted litter amendment composition corresponds to a
targeted low relative humidity interior environment having about
50% or less relative humidity.
[0023] In a second characterization, the presently disclosed
technology takes the form of a method for providing an ammonia
abatement additive for poultry litter that is formulated to
activate prior to the introduction of poultry onto the litter. The
method comprises providing an amount of deliquescent salt having a
first weight and providing an amount of aluminum sulfate having a
second weight, and wherein the amount of aluminum sulfate is about
one and one-half times the amount of deliquescent salt, based on
weight.
[0024] In one example, the ammonia abatement additive for poultry
litter is formulated to activate in average US relative humidity.
For present purposes, average US relative humidity is considered to
be about 60% relative humidity.
[0025] In another example, the additional amount of provided
aluminum sulfate is approximately equal to twice the amount of
already-provided deliquescent salt, based on weight. In this case,
the additional amount of aluminum sulfate is provided in
correspondence with a use-environment of greater than 70% relative
humidity.
[0026] In yet another example, the additional amount of provided
aluminum sulfate is approximately equal to three times the amount
of already-provided deliquescent salt, based on weight. In this
case, the additional amount of aluminum sulfate is provided in
correspondence with a use-environment of greater than 80% relative
humidity.
[0027] In still another example, the additional amount of provided
aluminum sulfate is approximately equal to four times the amount of
already-provided deliquescent salt, based on weight. In this case,
the additional amount of aluminum sulfate is provided in
correspondence with a use-environment of greater than 90% relative
humidity.
[0028] In the second characterization disclosed above, the
deliquescent salt constitutes about 40% and the aluminum sulfate
constitutes about 60% of the combination of the two components.
[0029] In an additional characterization, the presently disclosed
technology takes the form of a method for providing an ammonia
abatement additive for poultry litter that is formulated to
activate prior to the introduction of poultry onto the litter. The
method comprises providing an amount of aluminum sulfate having a
first weight and providing an amount of deliquescent salt having a
second weight, and wherein the amount of aluminum sulfate is about
nine times the amount of deliquescent salt, based on weight. This
combination has been found to be particularly useful when the alum
has not been activated until shortly before chick introduction.
Related Embodiments Described in Terms of Comprising Activating
Agent and Drying Agent
[0030] Alternatively, the litter amendment can be characterized as
comprising an activating agent and a drying agent as depicted in
FIG. 1. The activating agent is an acid having a pKa of about 3 or
less. Suitable acids include, without limit, benzenesulfonic acid,
chloric acid, chromic acid, ethanesulfonic acid, fluoroboric acid,
fluorosulfuric acid, hexafluorophosphoric acid, hydrochloric acid,
hydrobromic acid, hydroiodic acid, methanesulfonic acid, nitric
acid, perchloric acid, periodic acid, permanganic acid, phosphoric
acid, sulfuric acid, p-toluenesulfonic acid,
trifluoromethanesulfonic acid, and combinations thereof In some
embodiments, the activating agent may be sulfuric acid,
hydrochloric acid, phosphoric acid, nitric acid, perchloric acid,
or a combination thereof. In specific embodiments, the activating
agent acid may be sulfuric acid.
[0031] The amount of activating agent present in the litter
amendment can and will vary depending upon a variety of factors
such as, e.g. the moisture content of the animal litter.
[0032] The drying agent in the litter amendment comprises a metal
salt. Suitable metal salts include, without limit, aluminum
sulfate, aluminum chloride (basic), aluminum oxide, aluminum
hydroxide, ferric aluminum sulfate, ferric chloride, ferrous
chloride, ferric sulfate, ferrous sulfate, or combinations thereof.
In some embodiments, the drying agent may be aluminum sulfate,
ferric aluminum sulfate, aluminum chloride (basic), ferric,
chloride, ferrous chloride, ferric sulfate, ferrous sulfate, or
combination thereof. In specific embodiments, the drying agent may
be aluminum sulfate. The aluminum sulfate may be expressed as a
stoichiometric equivalent to a hydrated form of aluminum sulfate
(Al.sub.2(SO.sub.4).sub.3.nH.sub.2O, wherein n is an integer from
12 to 18), or an anhydrous form of aluminum sulfate.
[0033] The amount of drying agent present in the litter amendment
can and will vary depending upon a variety of factors such as, e.g.
the moisture content of the animal litter.
[0034] In some embodiments, the litter amendment may be formulated
as a liquid composition. The liquid composition may further
comprise water. The water may be tap water, process water, rain
water, spring water, well water, storm water, river water, pond
water, lake water, acid water, alkaline water, purified water, or
distilled water. An exemplary liquid litter amendment consists of
sulfuric acid, aluminum sulfate, and water.
[0035] In other embodiments, the litter amendment may be formulated
as a dry composition. The dry composition may further comprise one
or more inert ingredients. Exemplary inert ingredients include
starches, celluloses, clays, bentonite, diatomaceous earth, talc,
kaolin, lime, soda ash, silicon dioxide, or combinations
thereof.
[0036] In general, the litter amendment has a pH of about 6.0 or
less. In some embodiments, the litter amendment has a pH of less
than 6.0, less than 5.0, less than 4.0, less than 3.0, less than
2.0, less than 1.0, or less than 0.5.
[0037] This method comprises applying a litter amendment comprising
an activating agent and a drying agent to the animal litter,
wherein the litter amendment comprises amounts of the activating
agent and the drying agent that vary as a function of moisture
content of the animal litter. As such, the method comprises
determining or estimating the moisture content of the animal litter
and adjusting the ratio of activating agent to drying agent
according to the moisture content of the animal litter. Typically,
the lower the moisture content of the animal litter, the higher the
ratio of activating agent to drying agent and/or the higher the
moisture content of the animal litter, the lower the ratio of
activating agent to drying agent.
[0038] In embodiments in which the moisture content of the animal
litter is less than 25%, the litter amendment comprises a higher
ratio of activating agent to drying agent. For example, the litter
amendment comprises from about 1.30 mole to about 7.62 moles of the
activating agent per 1.0 mole of the drying agent. In various
embodiments, the mole to mole ratio of the activating agent to the
drying agent may be about 1.3:1, about 1.5:1, about 1.5:1, about
2.0:1, about 2.2:1, about 2.5:1, about 3:1, about 4:1, about 5:1,
about 6:1, or about 8:1. In certain embodiments, the mole to mole
ratio of the activating agent to the drying agent may range from
about 1.3:1 to about 1.5:1, from about 1.5:1 to about 1.8:1, from
about 1.8:1 to about 2.2:1, from about 2.2:1 to about 2.8:1, or
from about 2.8: to about 3.5:1. In embodiments in which the
moisture content of the animal litter is less than 25%, the
activating agent is sulfuric acid, and the drying agent is aluminum
sulfate, the litter amendment comprises about 1.3 to about 2.2
moles of sulfuric acid per 1.0 moles of aluminum sulfate.
[0039] In embodiments in which the moisture content of the animal
litter ranges from about 25% to about 30%, the litter amendment
comprises from about 1.07 to about 1.28 moles of the activating
agent per 1.0 mole of the drying agent. In some embodiments, the
mole to mole ratio of the activating agent to the drying agent may
be about 1.08:1, about 1.00:1, about 1.12:1, about 1.14:1, about
1.16:1, about 1.18:1, about 1.20:1, about 1.22:1, about 1.24:1,
about 1.26:1, or about 1.28:1. In various embodiments, the mole to
mole ratio of the activating agent to the drying agent may range
from about 1.07: to about 1.10:1, from about 1.10:1 to about
1.15:1, from about 1.15:1 to about 1.20:1, from about 1.20:1 to
about 1.25:1, or from about 1.25:1 to about 1.28:1. In embodiments
in which the moisture content of the animal litter is from about
25% to about 30% the activating agent is sulfuric acid, and the
drying agent is aluminum sulfate, the litter amendment comprises
about 1.07 to about 1.28 moles of sulfuric acid per 1.0 mole of
aluminum sulfate.
[0040] In embodiments in which the moisture content of the animal
litter is greater than 30%, the litter amendment comprises a lower
ratio of activating agent to drying agent. In various embodiments,
the litter amendment comprises from about 0.03 to about 1.06 moles
of the activating agent per 1.0 mole of the drying agent. In
various embodiments, the mole to mole ratio of the activating agent
to the drying agent may be about 1.03:1, about 0.1:1, about 0.2:1,
about 0.4:1, about 0.6:1, about 0.8:1, or about 1.0:1. In certain
embodiments, the mole to mole ratio of the activating agent to the
drying agent may range from about 0.03:1 to about 0.1:1, from about
0.1:1 to about 0.4:1, from about 0.4:1 to about 0.6:1, from about
0.6:1 to about 0.8:1, or from about 0.8:1 to about 1.06:1. In
embodiments in which the moisture content of the animal litter is
greater than 30%, the activating agent is sulfuric acid, and the
drying agent is aluminum sulfate, the litter amendment comprises
about 0.39 to about 1.06 moles of sulfuric acid per 1.0 moles of
aluminum sulfate.
[0041] The amount of the litter amendment applied to the animal
litter can and will vary depending, for example, upon the
temperature and amount of ventilation in the animal facility, the
depth, and/or age of the animal liter. In embodiments in which the
litter amendment is a liquid composition, the liquid composition
may be applied at a rate from about 0.25 gallon to about 1 gallon
per 100 ft.sup.2, from about 1 gallon to about 2 gallons per 100
ft.sup.2, from about 2 gallons to about 3 gallons per 100 ft.sup.2,
or from about 3 gallons to about 6 gallons per 100 ft.sup.2 of
surface area. In embodiments, in which the litter amended is a dry
composition, the dry composition may be applied at a rate from
about 0.5 to 2 lbs per 100 ft.sup.2, from about 2 to 4 lbs per 100
ft.sup.2, from about 4 to 6 lbs per 100 ft.sup.2, from about 6 to 8
lbs per 100 ft.sup.2, from about 8 to 10 lbs per 100 ft.sup.2, from
about 10 to 12 lbs per 100 ft.sup.2, from about 12 to 15 lbs per
100 ft.sup.2, from about 15 to 20 lbs per 100 ft.sup.2, or from
about 20 to 30 lbs per 100 ft.sup.2 of surface area.
[0042] The liquid composition may be applied to the animal litter
using a spot sprayer, a boom sprayer, a mist sprayer, a hitch
sprayer, a backpack sprayer, a tow sprayer, a boomless sprayer, a
stationary or moving sprayer system affixed to the animal facility,
or any other sprayer device known in the field. The dry composition
may be applied to the animal litter using a spinner spreader, a
broadcast spreader, a drop spreader, a lime spreader, a litter
spreader, a fertilizer spreader, or any other spreader know in the
field.
[0043] The frequency of application of the litter amendment will
vary depending, for example, upon the age, depth, and/or density of
the animal litter. In some embodiments, the litter amendment may be
applied every month, every two months, every three months, every
six months, every year, every two years, and so forth.
[0044] The animal litter treated by the methods described herein
may be from livestock animals such as poultry (e.g., boilers,
turkeys, ducks, geese, pheasants, game birds, layers, etc.), cattle
(e.g., dairy, beef, veal, etc.), pigs, sheep, and goats; companion
animals such as cats, dogs, horses, rodents (e.g., mice, rats,
hamsters, gerbils, guinea pigs), and the like; zoo animals such as
monkeys, chimpanzees, lions, tigers, elephants, giraffes, and so
forth; or research animals such as mice, rats, and the like. In
specific embodiments, the animal litter may be poultry litter or
chicken litter.
[0045] The activating agent/acid in the litter amendment provides
an immediate source of protons, thereby immediately acidifying or
lowing the pH of the animal litter. In general, the pH of the
litter is reduced to a level of less than about 6.0, less than
about 5.0, less than about 4.0, less than about 3.0, or less than
about 2.0. The protons also react with (or bind) volatile ammonia
(NH.sub.3) to form non-volatile ammonium (NH.sub.4.sup.+). Ammonium
is a highly reactive cation that bonds with sulfates, nitrates,
phosphates, or other anions to form ammonium salts. For example,
ammonium ions can react with sulfates to form ammonium sulfate, a
water soluble nitrogen fertilizer. The presence of ammonium salts
in animal litters improves their nutrient value use as fertilizers.
The drying agent/metal salt in the litter amendment undergoes
hydrolysis to form buffered metal hydroxide intermediates and
protons. The metal hydroxide intermediates can react with the
activating agent (e.g., sulfuric acid) to form acidic metal
sulfates, which are then hydrolyzed to form buffered metal
hydroxide intermediates and additional protons. The continued
generation of protons maintains the animal litter a low pH and
controls ammonia volatilization.
[0046] Minimizing ammonia volatilization also reduces the levels of
airborne ammonia in animal facilities. The generally recognized
acceptable level of airborne ammonia in animal facilities is about
25 parts per million (ppm) or less. In some embodiments, the level
of ammonia in the animal facility may be less than about 25 ppm,
less than about 20 ppm, less than about 15 ppm, less than about 10
ppm, less than about 5 ppm, or less than about 1 ppm. Ammonia
levels may be monitored and measured by a variety of means.
Suitable means include ammonia meters, ammonia detection devices,
ammonia sensors, ammonia gas monitors, colorimetric test strips,
colorimetric paper, passive colorimetric tube detectors for
ammonia, active colorimetric tubes for ammonia, and other detection
means well-known in the art. In general, animal facilities treated
with the composition have lower levels of airborne ammonia than
comparable untreated animal facilities.
[0047] Reducing airborne ammonia levels in animal facilities,
therefore, improves air quality in animal facilities. Improved air
quality (i.e., low ammonia levels) improves the quality of life for
animals housed in the animal facility and reduces the physiological
stress of the animals. Animals with reduced stress generally have
increased weight gain, better feed conversion ratios, increased
productivity (e.g., increased egg production, increased milk
production, etc.) and/or fewer infections or diseases than stressed
animals. Improved air quality (e.g., low ammonia levels) also
provides better working conditions for the animal facility workers.
Reducing the levels of airborne ammonia may also reduce the amount
of energy needed to ventilate and/or heat the animal facilities.
Lastly, inhibiting ammonia volatilization may also reduce odor from
animal litter and/or animal facilities.
[0048] Animal litter also contains soluble phosphorus that can
enter the aquatic groundwater system from fields receiving
untreated animal litter. Phosphorus runoff is the primary cause for
eutrophication in lakes and other freshwater bodies. The soluble
phosphorous in the animal litter can react with the metal of the
metal salt of the litter amendment to form insoluble metal
phosphates. For example, phosphorus in the animal litter can react
with aluminum to form aluminum phosphate. Thus, this method of
treating animal litter also reduces runoff of soluble phosphorous
as compared to untreated animal litter.
[0049] This method of treating animal litter can also adjust or
maintain the moisture content of the animal litter within an
optimal range. In some embodiments, the animal litters treated as
described herein may have moisture contents that range from about
20% to about 35%, or more preferably from about 25% to about
30%.
[0050] Although the present technology has been described in terms
of specific components and relative amounts thereof, other
additives can be included as will be known to one skilled in the
art. Thus the disclosed technology is only meant to be limited by
the scope of the appended claims.
* * * * *