Note: Descriptions are shown in the official language in which they were submitted.
CA 02462346 2004-03-24
METHOD AND APPARATUS FOR TREATING PIG MANURE
FIELD OF INVENTION
The present invention relates to a method and apparatus for the treatment of
liquid manure. More particularly the invention provides an economical,
efficient
and environmentally friendly method and the equipment for treatment of the
liquid faction of manure, or any particular phosphor containing waste water
that
may need that kind of treatment, in order to balance its main fertilizing
elements,
mainly nitrogen and phosphor so that it can be used productively as a
fertilizer or
other use. The resulting balanced manure or treated water will correspond to
the
needs of the plants and the phosphor saturation level of the soil where it
will be
spread. The described method and equipment described further can apply to
manure or other phosphor containing waste waters.
BACKGROUND OF THE INVENTION
Pig production constitutes an important agricultural and economical activity.
However this production, particularly managing manure has generated some
environmental problems affecting water resources. Spreading untreated manure
on agricultural lands for fertilization is a common practice. However, these
lands
quickly become saturated with phosphor and the excess phosphor flows towards
surrounding waterways. Usually, the farm doesn't have sufficient surfaces for
the
animal wastes that it produces; also the totality of local agricultural lands
are not
sufficient to receive all the animal wastes on a given territory.
Consequently; the
phosphor needs of the land are usually exceeded.
The composition of manure, including phosphor and nitrogen is a function of
several factors including the specific food given to the pigs and thus can
vary.
The phosphor in the liquid manure is usually in the form of phytate, which is
the
salt of phytinic acid, dihydrogen phosphate, and consists of a sugar molecule
with
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six phosphate molecules. Single stomach animals such as pigs are not capable
of
absorbing sufficient phosphate from their feed and accordingly, a large part
of it
finds its way, substantially undigested, into the manure of the animal. The
pigs
need phosphor for a good bone structure and since they are unable to absorb
sufficient phosphate from their feed, extra phosphor is often added to the
feed. In
pig farming, the animals are kept in one of three different areas according to
its
maturity stage: the first area is the maternity area, a second area where they
stay
in a nursery type of arrangement , and a final area where the pigs are
fattened for
slaughter. Each of the pig manures coming from the three areas has somewhat
different properties.
Several technologies have already been proposed or are under investigation to
solve this problem of excess phosphor in pig manure and in culture fields.
Some
of these technologies requires investment on the part of the pig producer, if
he
wants to do the treatment himself. Other methods involve the costly
transportation of manure for treatment in a special plant or facility or
involve the
use of chemical products including "polymers" which the farmers want to avoid
because of the unknown long term effects on soils, plants, animals and humans.
The object of this invention is to propose a simple, economical and fast
method
to treat liquid manure and other waste liquid in order to balance its
fertilizers
content corresponding to the needs and to the phosphor saturation level where
it
will be spread. This method takes into account the following attributes.
D Productive usage of elements from the environment (manure and mineral
components );
D Preservation of the environment
D Proper use of agricultural land
D Limit the transport of waste liquids
D Absence of polymenic material and other non biodegradables
D Provide a liquid which is ready to use as a fertilizer
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~ Capable of being processed on site
~ Provide fast processing
SUMMARY OF THE INVENTION
It is an object of the invention to provide a method and equipment for the
treatment of a liquid such as liquid manure.
It is a further object of the present invention to provide a method and
apparatus for the treatment of liquid manure wherein quarry fines are used
for reducing the phosphor content of the liquid phase, and producing
manure more balanced with regards to Nitrogen phosphor for fertilization
of soils with a high content in phosphor.
It is a further object of the present invention to provide mobile equipment
for the treatment of liquid manure comprising a first system that mixes the
liquid faction with an adequate quantity of quarry fines, a second system
that blends the mixture in a way to favor the fixation reaction between the
mineral components and the liquid phosphor and a third system that
separates the liquid from the mineral components and other solids.
Referring initially to Figure 1, providing graphs showing the concentration
of various components of the liquid pig manure, the control was done
without mechanical separation of the liquid faction; however, mechanical
separation was done before treatment for products P1, P2, P3 and P4. In
this regard, trial P1 utilized quarry fines from a pig having a substantial
portion of limestone; P2 were fines from a different quarry;
P3 were from a quarry having a shale type structure and P4 was
slag from a metal processing operation.
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In greater detail, in a first step, manure with a minimal solid faction
proportion should be attained since there is a desirable level. If the solid
matter, that is the organic form, is higher than this desirable level, then
the
manure is desirably processed by a mechanical separator to remove as
much solid matter as possible from the original manure to attain a
proportion close to this desirable value. There are several commercial
known separators that could do the work. However it has been found that
the method is most efficient only upon attainment of the right percentage
(or lower) of solid matter. Once this prerequisite is attained, then,
measures of the nitrogen and phosphorus content, and, possibly other
measures, are taken from the liquid manure and from the soil on which the
fertilizers would be used after the process.
Pig manure decants naturally in a tank. Accordingly, approximatively ~/ of
the volume of manure in a tank is a liquid phase of the manure that can
be recuperated with a pump. This liquid is rich in ammonium and
potassium but is normally weak in phosphor content. If the
nitrogen/phosphorus ratio is adequate, large quantities of this liquid
manure can be applied to the lands to provide fertilization. If the dosage,
such as an excess of phosphorus is not adequate, then a treatment is
advised before spreading.
On the other hand, the bottom of the manure tank , contains one quarter of
the gross pig manure which normally has a rich mineral, organic and
phosphor content. The proportion of solids normally ranges from 8 to
12°!0.
Treating this substance through a mechanical separator will produce a
liquid high in phosphor content. The nitrogen and phosphorus
concentrations of that liquid might not be adequate to fertilize fields
already rich in phosphorus content. The agronomic needs of the fields are
ideally included within a range of value of N/P205 from 5 to 7. Once
nitrogen and phosphorus concentrations are determined and the value
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CA 02462346 2004-03-24
nitrogen/phosphorus calculated, it is possible to consider a treatment with
mineral components including quarry fines rich in calcium or iron or other
known minerals to attain the desired NIP205 value.
In the presence of high solid contents, quarry fines are somewhat less
efficient to reduce the phosphor content in pig manure. The organic matter
may block the action of the quarry fines on the phosphor. Therefore one
should reduce the organic solid content to a very low proportion. There are
several commercial equipments that can be used to reduce the organic
solid content of a manure solution.
In a second step, once proper measures of the liquid manure are taken and once
some clear objectives of the values of phosphor and nitrogen are determined,
quarry material which comprises an adequate quantity of quarry fines are added
and mixed with the liquid manure in a first operation. The period of time
required
for this operation can range from fifteen minutes upwardly.
Phosphor in the manure can be found either in mineral or organic form.
The mineral form of phosphor, that is mainly composed of
orthophosphates is very soluble. It also reacts strongly with minerals such
as calcium and iron. The addition of natural products rich in content of
these available minerals would reduce the phosphate content in the liquid
phase of manure, increasing the phosphate content in the solid phase.
Accordingly, it has been found that the quarry fines which have a very high
surface area, remove a substantial portion of the phosphor from the liquid
faction. An advantage of the present method is that the mineral
components including quarry fines over a certain period of time appear to
"fixes the phosphor. And accordingly, one is then provided with a liquid
which is then suitable for use as a fertilizer.
CA 02462346 2004-03-24
In a third step, optimized conditions are maintained to trigger, propagate and
accelerate the reaction within this mixture that will solidify some of the
phosphor.
This operation can take from 30 minutes to an hour depending on the type of
mineral components used and on the degree of saturation of phosphor and /or
organic matter. For a proper reaction to happen, the mixture must be
maintained
homogeneous to maximize even distribution of mineral components in the
mixture, avoiding vigorous blending so the new bonds created between
molecules are not broken. As such, a propeller at either the bottom, or top of
the
equipment, functioning at a moderate speed can ensure that the mineral
components are distributed and not accumulated at the bottom of the container.
Other devices could also be used.
In a fourth step, the solid components of the mixture are mechanically
separated
from the remaining balanced liquid manure. For example a worm screw could be
used for this function, without excluding any other device. Accordingly; one
is
then provided with a liquid which is then suitable for use as a balanced
fertilizer
w~h the proper nitrogenlphosphorus value.
As aforementioned, there is also provided a mobile unit adapted to treat
manure.
In this method and as is conventional in pig farming, the manure would
initially be
restricted to a settling operation on the pig farm. Subsequently, the mobile
equipment could include three sections to carry out sequential operation on
the
liquid manner. Thus the liquid manure is mixed with a predetermined amount of
mineral components . The mixture is stirred and a reaction between these stone
fines and liquid manure allowed to proceed. Subsequently, the solids some of
which are rich in phosphor, are extracted.
The mixing of mineral components including quarry fines with the liquid manure
will be carried out on the basis of a measurement of the properties of the
liquid
manner. Such techniques are well known in the art.
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Subsequently, the mixture is directed to one or several cisterns and may be
proportioned in such a manner that it standardizes a reaction between
components.
The anal section of the mobile unit would function to provide a separation of
the
liquid from the solids phase which consist primarily of the quarry fines and
fixed
phosphor.
BRIEF DESCRIPTION OF DRAWINGS
Having thus generally described the invention, reference will be made to the
accompanying tables and figures illustrating different aspects of the
invention,
wherein:
Figure 1a is a graph providing the total nitrogen content when the liquid
manure is treated with different materials;
Figure 1 b is a graph illustrating the phosphorus content thereof;
Figure 1 c is a graph illustrating the N/P2 OS ratio thereof;
Figure 1d is a graph illustrating the ammonium content thereof;
Figure 2 is a graph illustrating the results of a treatment of the liquid
manure with different components and shows the phosphorus content versus
reaction time;
Figure 3 shows the separation time of mineral components for different
types of pig manure;
Figure 4 is a schematic view of a method for the treatment of manure;
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Turning initially to Figure 4, there is illustrated an apparatus for carrying
out
the process of the present invention and which apparatus is schematically
illustrated.
Thus, there is provided a first container 10 to receive the liquid manure.
Therein, the liquid manure will separate into a solids faction 12 and a liquid
faction 14. Liquid faction 14 is transferred through conduit 16 to a
mechanical
separator 18. The solids content is then transferred to a storage 20 where it
can
be used for many different purposes. The liquid portion is transferred through
conduit 22.
From container 10, the liquid faction is transferred through conduit 24
which meets with conduit 22 and the liquid is transferred to a mixing
container 26.
Quarry fines 28 are then transferred through line 30 to container 26 where
the two are mixed and allowed to react. Subsequently, the mineral solids are
transferred to storage 29 while the treated liquid, reduced in phosphor, is
transferred by conduit 30 to a equilibrium container 32. Subsequently, the
liquid
may be transferred through conduit 34 for use as a fertilizer.
Naturally, it will be understood that suitable pumps and the like may be
utilized for the transfer of the solidslliquids and it is within the skill of
one
knowledgeable in the art to do so.
Various trials were run utilizing different types of material. The results are
illustrated in Figures 1A through 1 D.
In this trial,
P1 indicated quarry fines which came from a limestone ridge quarry;
P2 came from a further quarry;
P3 came from a quarry which was rich in a shale type structure; and
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CA 02462346 2004-03-24
P4 represented stags from a metal plant.
Figure 2 is a graph of the NPZOS versus the reaction time for the various
types of mineral additives.
In Figure 3, there is illustrated the sedimentation time for manure from
different stages of the pig's development.
It will be understood that the above described embodiments are for
purposes of illustration only and that changes and modifications may be made
thereto without departing from the spirit and scope of the invention.
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