Note: Descriptions are shown in the official language in which they were submitted.
CA 02566562 2006-10-31
SYSTEM AND PROCESS FOR PRODUCING A LOW-SUSPENDED SOLIDS SOLUTION
AND USES THEREFORE
FIELD OF THE INVENTION
The present invention relates generally to a system and process for producing
a low-
suspended solids solution by filtering a solution through a column comprising
crushed shells derived
from mollusks. More specifically, the present invention relates to a system
and process for
manufacturing a low-suspended solids solution having cleaning, disinfecting,
and medical treatment
properties. Additionally, the present invention relates to a method for
preparing an ointment useful
for medical treatments in which the ointment comprises in part a composition
of crushed shells.
BACKGROUND OF THE INVENTION
Shells derived from mollusks are generated as industrial waste from fisheries
around the
world. It is common practice to dump the shell waste into the ocean. However,
shells have been
efficiently used as a source of calcium and for obtaining antibacterial agents
as well as for purifying
water. It has been shown that the powder obtained from shells of scallops,
oysters, clams, and other
mollusks or a solution containing the powder has antibacterial and antiviral
properties, as well as use
as a water purifying agent. It has also been found that the aforesaid powder
has demonstrated useful
properties when applied as a deodorant for sterilization as a preservative
agent and for selected
medicinal use.
Antibacterial properties of shell powder are well proven and tested, e.g., the
treatment of
dermathophytosis (U.S. Patent Application No. 2004/0028748), periodontal
diseases (European
Patent Application No. 1676583) or for relieving the irritation caused by
atopic dermatitis lesions,
psoriasis lesions, and for kidney dialysis (Japanese Patent Application No.
2004/256785). Shell
powder can also be used in soaps which have been shown to treat tinea pedis
(athlete's foot) caused
by the breeding of a true fungus.
Japanese Patent Application No. 05-267807 (Ueda et al.) describes a method for
purifying
polluted water as well as the bottoms of rivers, lakes, seas and bays, by
spreading a powder of shell
fossils across the sea bed to purify the polluted water and the bottoms of
rivers.
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CA 02566562 2006-10-31
Japanese Patent Application No. 08-316935 (Suzuki et al.) describes a porous
material, made
of calcined shells, for purifying water. The material has been shown to
effectively purify the water
and may be applied effectively for large scale water purification.
Japanese Patent Application No. 11-328702 to Sasaya discloses a deodorant
obtained by
pulverizing the shells of scallops having a crystalline structure consisting
of a calcite type structure
of calcium carbonate.
U.S. Patent Nos. 6,365,193 and 6,488,978 to Sasaki et al. disclose that burned
shells can be
used as antibacterial agents and water purifying agents. Sasaki et al.
disclose heating a shell in an
atmosphere of inactive gas and burning the shell. In particular, the
antibacterial agent is obtained by
burning a powder from the shell of a surf clam in an atmosphere of inactive
gas. The powder can be
easily dissolved into water, in particular warm water and used as an
antibacterial solution.
The above uses of shells demonstrate the vast area of applications in which
shell properties
can be exploited. Further developments directed to new uses of shell material
are desired and needed
to manage and reduce the great quantity of shell waste produced every year.
Most of the above-identified applications require the use of a powder obtained
from the shells
of mollusks or heat treatment under high temperatures and special conditions,
both of which
consequently require expensive equipment and complex set-up procedures to
practice. In addition,
it has been found that when the powder is dissolved in water, the powder tends
to lose its active
properties over the course of time.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a simple process for
obtaining a low-
suspended solids shell extract, containing mainly calcium, that is safe for
the human body and
environmentally friendly. The low-suspended shell extract inherits the
antibacterial properties of the
shells and as indicated heretofore may effectively be applied as a cleaner and
disinfectant or for the
treatment of skin diseases. The resultant solution can also be used as a fluid
or in mixture with a
suitable vehicle to provide a solid or mastic composition.
Moreover, the system and process of the present invention are simple and by
being
economically advantageous can be applied at a larger industrial scale for
cleaning and purifying
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CA 02566562 2006-10-31
contaminated water.
In accordance with an aspect of the present invention, there is provided a
process for
removing suspended solids from a solution, comprising repeatedly filtering the
solution through a
filter/extraction column housing crushed mollusk shell particles.
In accordance with another aspect of the present invention, there is provided
a device for
removing suspended solids from a solution, comprising a filter/extraction
column; a fluid inlet
positioned on one end of the filter/extraction column; and a fluid outlet
positioned on the other end
thereof, wherein the filter/extraction column houses crushed mollusk shell
particles.
In accordance with a further aspect of the present invention, there is
provided an apparatus
for removing suspended solids from a solution. The apparatus may comprise a
filter/extraction
column; a fluid inlet positioned on one end of the filter/extraction column;
and a fluid outlet
positioned on the other end thereof, wherein the filter/extraction column
houses crushed mollusk
shell particles, effectively assembled for removal of said suspended solids.
In accordance with a preferred aspect of the present invention, there is
provided an apparatus
comprising two filter extraction columns arranged in tandem, wherein the first
filter/extraction
column houses crushed mollusk shell particles and the second filter/extraction
column houses
crushed mollusk shell particles pre-coated with iron oxide or hematite.
In accordance with another aspect of the present invention, there is provided
a low-suspended
solids solution produced by the process described above.
In accordance with a further aspect of the present invention, there is
provided a use for the
low-suspended solids solution for treatment of skin diseases.
Another object of the present invention seeks to provide a cleaner composition
comprising
the low-suspended solids solution alone or a mix of the solution and sodium
hydroxide (NaOH) at
a ratio of 0.4 % by weight. This weight factor may vary as may be determined
by the man skilled
in the art while maintaining cleaning effectiveness.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features of the present invention will become more
apparent from the
appended drawings, wherein:
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Fig. 1 shows a cross-sectional view of the extraction column comprising an
inlet, an outlet,
and a housing member;
Fig. 2a is an exploded cross-sectional view of the upper half of the
extraction column and
illustrates the empty column set-up;
Fig. 2b is an exploded cross-sectional view of the upper half of the
extraction column and
illustrates the column filled with the packing member;
Fig. 3 is an exploded cross-sectional view of the lower half of the extraction
column and
illustrates the empty column set-up;
Fig. 4 illustrates a cross-sectional view of the apparatus comprising two
extraction columns
in a tandem arrangement;
Fig. 5 illustrates the measured turbidity of the shell extract with exposure
time; and
Fig. 6 illustrates the increase of the amount of calcium determined in the
shell extract with
exposure time.
DETAILED DESCRIPTION OF THE INVENTION
The following description is directed to a preferred embodiment by way of
example of only
one of the potential uses of the present invention.
Fig. 1, illustrates a filter/extraction column (10) comprising an inlet (11),
an outlet (13), two
screens (14), and a housing member (12). The housing member (12) defines a
passageway (12a) that
can be filled with crushed mollusk shells.
Fig 2a, illustrates an exploded view of the upper half of the
filter/extraction column (10),
comprising a top coupling (16), a screw-in stopper (15) and an outlet (13)
placed in the stopper (15).
A screen (14) may be placed at the top of the housing member (12) in order to
contain the crushed
mollusk shells in the filter/extraction column (10). The top coupling (16) is
fitted with a coupling
inside lip (17) in order to attach the screen (14) to the housing member. An
interchangeable seal
(18), such as silicon can be used to inhibit leaking of the column.
Fig. 2b, illustrates an exploded view of the lower half of the extraction
column, comprising
the bottom coupling (16), stopper (15) and an inlet (11) placed in the stopper
(15). The bottom
coupling can also be fitted with the coupling inside lip (17) in order to
attach the screen (14) to the
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CA 02566562 2006-10-31
housing member (12) so as to contain the crushed mollusk shells into the
filter/extraction column.
The inlet (11) is designed for connection to a plastic valve and a pump used
to feed the column with
the solvent. An interchangeable silicon seal (18) can be used to avoid leaking
of the column.
Fig. 3, illustrates the filter/extraction column (10), comprising an inlet
(11), an outlet (13),
top and bottom identical screens (14), and a housing member (12). The housing
member (12)
contains crushed mollusk shell particles which may be of equal or different
sizes. In one
embodiment shown in Fig. 3 the housing member contains at the bottom thereof
crushed shell
particles of sizes between 0.5 and 1 mm in diameter (20) and crushed shell
particles of sizes between
3 and 4 mm in diameter (21). However, the crushed mollusk shells can comprise
size particles of
about equal and/or of particles distributed along the passageway according to
the filter/extraction
needs in one or a plurality of zones. A zone is defined as containing crushed
shell particles of
approximately the same diameter. The packing of the column with crushed shell
particles can follow
a regular distribution according to a desired gradient or an irregular
distribution. Heat treatment can
be applied to shells prior to crushing at a temperature of approximately 300
C for a period of
approximately 1.5 min.
Fig. 4, illustrates a cross-sectional view of the apparatus (1) according to
the present
invention and comprises at least two filter/extraction columns (2,3), in a
tandem arrangement. In the
two-column apparatus (1) the filter/extraction columns are arranged linearly
so that the outlet (13)
of the first column (2) is connected to the inlet (11) of the second column
(3) by a connecting tube
(23). The housing member (12) of the first column (2) can contain at the
bottom thereof crushed
shell particles of sizes between 0.5 and 1 mm in diameter (20), and crushed
shell particles of sizes
between 3 and 4 mm in diameter (21) thereafter. The housing member (12) of the
second column
(3) may contain crushed shell particles coated with iron oxide or hematite
(24). It is believed that
coating the crushed shell particles with iron oxide or hematite may
substantially improve the water
purifying properties of the filter/extraction columns by reducing the metal
content in the water
passed through the apparatus (1). Analysis of the water passed through the
filter/extraction columns
apparatus (1) showed nearly zero content of aluminum and arsenic in
contaminated water.
In the practice of the present invention, shells are collected directly off
the fishing boat and
put in tote boxes. The shells are then cleaned by electric drills having a
wire brush and throughly
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CA 02566562 2006-10-31
washed with water under high pressure to ensure effective cleaning. The
cleaning and washing steps
may be followed by a cooling step in which the shells are left on a wire rack
for an amount of time
necessary to cool the shells to the ambient temperature. In the next step the
shells are crushed to
particles of 1, 2, 3, and 4 mm in diameter. Particles of about the same
diameter or a mix of particles
with different diameters may be used in the filter/extraction column according
to the present
invention.
The effectiveness of the cleaner will be determined by several factors
including the pH of the
solvent and the particle size of the crushed shells that form the packing
member of the extraction
column. By passing distilled water through the filter/extraction column (10)
one can control,
amongst other parameters, the turbidity, the calcium content, and the
suspended solids of the extract.
The number of passes and the water flowrate determine the properties of the
cleaner, including its
cleaning effectiveness. The particle diameter of the crushed shells has been
shown to be inversely
proportionate to the effectiveness of the cleaner. For example, it is
preferred that the particle
diameter of the crushed shell be between 0.5 and 4 mm, more preferably between
0.5 and 2 mm to
produce a low-suspended solids solution effective as a cleaner.
Fig. 5, illustrates the Turbidity vs. Exposure time as determined in
Experiment 1 detailed
below. It will be noted that the measured turbidity of the solution decreases
as it is subject to
exposure time to the filter/extraction column. The turbidity was measured
after each pass of solvent
through the extraction column. After an exposure time of 12 hours the measured
turbidity of the shell
extract was about 2.2 NTU. The above measurements of turbidity are correlated
with the
measurements of the amount of suspended solids in the shell extract after each
pass. Accordingly,
as is shown in Table 1 of Experiment 1 as time passes the amount of suspended
solids decreases
from 6 mg/L after the first pass of solvent through the filter/extraction
column to about 0 mg/L after
12 hours.
Fig. 6 illustrates the amount of calcium measured after each pass of water
through the
extraction column versus the exposure time. The final shell extract contains
approximately 121
times more calcium than the starting solvent. It is preferred that the calcium
content of the shell
extract is higher than 14 mg/L and more preferably is higher than 20 mg/L.
Other factors that can
impact upon the effectiveness of the cleaner are the pH and the turbidity of
the shell extract. In order
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CA 02566562 2006-10-31
to optimize cleaning results the pH of the shell extract should be between 8.0
and 9.7 and the
turbidity should be less than 6 NTU.
Experiment 1
An extraction column (10) was constructed with a 6 inch diameter 4 feet long
PVC pipe with
two couplings closing each end as described in Figure 1. The top coupling had
a 90 elbow screw-in
with a 3/4 inch plastic tube connected thereto. The top coupling and the
plastic tube connected to
it represent the outlet (13) according to the present invention.
The bottom coupling as constructed had a straight adapter screwed in the
coupling stopper
and connected to a plastic tube representing the inlet (11) according to the
present invention. A 12
V, 360 gallon/hour pump was connected to the inlet of the column and was used
to pump distilled
water through the column. The top and the bottom of the column were designed
in the same way
except that the bottom coupling had a 3/4 nipple with a 3/4 plastic tube
connected to a plastic valve
and the 12 V pump. Two screens (14) as shown in Fig. 1 were used to keep the
crushed scallop shells
inside the passageway (12a).
The composition of the crushed shells was comprised of a mixture of 0.5 and 1
mm diameter
scallop shell particles. The mass of the smaller particles was approximately
10 kg and the column
was filled to within two inches of the screen (14) of the upper coupling. The
rest of the column was
filled with larger diameter particles of 3 and 4 mm.
After the first pass of distilled water the shell extract had a high suspended
solids
concentration. The suspended solids concentrations were found to diminish with
exposure time.
Table 1 shows the suspended solids concentration in the solution as measured
by the Hach Company
DR- 2400 Spectrometer. This method of determining suspended solids is a
simple, direct
measurement which does not require the filtration or ignition/weighing steps
as do gravimetric
procedures. While the USEPA specifies the gravimetric method for solids
determinations, this
method is often used for checking in-plant processes. Test results are
measured at 810 nm. This
method is documented in the Hach Water Analysis Handbook, method 8006 page
963.
The accuracy of the spectrometric method of measuring the suspended solids
concentration
was compared against the gravimetric method as described in the Hach Water
Analysis Handbook,
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CA 02566562 2006-10-31
method 8271 page 947. The mass of the aluminum dish was measured with a
Scientech 120
analytical balance to the nearest 1 mg. A 100 ml sample from the solution was
taken in situ and
placed into the aluminum dish. The dish with sample was placed in a preheated
oven and evaporated
at 103-105 C for approximately six hours. The dish was then taken out of the
oven and allowed to
cool at room temperature in a desiccator. The dish with sample was then taken
out of the desiccator
and mass measurements were effected to the nearest 0.1 mg with the Scientech
120 analytical
balance. This was the first mass measurement of the sample. The dish and
sample were put into the
preheated oven again for a period of one hour and mass measurements were
effected until the results
did not differ by more than 0.4 mg. A second measurement of the mass was done
in the same
manner as above. Table 2 below shows the suspended solids concentration in the
solution as
measured by the gravimetric method.
Total Solids Analysis
Table 2
itial tray ls' dried d dried weight Weight diff otal Solids
weight weight (g) g) ls' and 2 nd weight g/L
B (A) 0.4 mg
Tray 1 8.1982 8.2109 8.2106 0.0003 0.124
Tray 2 8.2245 8.2395 8.2393 0.0002 0.147
ra 3 8.31 8.3253 8.3250 0.0003 0.15
ra 4 8.2486 8.2620 8.2620 0.0000 0.144
ra 5 8.2659 8.2805 8.2806 0.0001 0.147
Total Solids Calculations
Equation: mg/L Total solids= ( A - B) X 1000
Sample volume ml
Where:
A= Weight (mg) of sample + tray
B = Weight (mg) of dish
% Error of Results
% of error =(Dh - Dl) x 100 =( 0.15 mg - 0.124ma) x 100 = 0.5 % error
# of data points 5
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CA 02566562 2006-10-31
Where:
Dh = Highest numerical data results obtained
Dl = Lowest numerical data results obtained
Experiment 2
Two extraction columns were constructed as indicated above in Experiment 1(see
Fig. 4).
The two columns were arranged in tandem with the outlet of the first column
directly connected to
the inlet of the second column. A 12 V, 360 gallon/hour pump was connected to
the inlet of the first
column and was used to pump distilled water through the first and second
column.
The packing member of the first column was made of a mix of smaller 0.5 and 1
mm in
diameter scallop shell particles. The mass of the smaller particles was about
10 kg while the column
should be filled two inches below the screen (14) of the upper coupling. The
rest of the column was
filled with larger diameter particles of 3 and 4 mm as described in Experiment
1.
The packing member of the second column was made of crushed scallop shell
particles
coated with iron oxide or hematite (Fe203). The coating of the crushed shell
particles with iron oxide
can be effected by any process known to a person skilled in the art. In the
present invention the
coating of the scallop shells is effected by soaking the shells in iron oxide
or hematite for 4 hours,
then baking the shells and solution for 4 hours at 200 C. The shells should
then be washed with
distilled water and dried in an oven at 200 C for three hours.
Contaminated water with a high content of aluminum and arsenic was passed
through the
apparatus comprising the two extraction columns arranged in tandem. It has
been found in practice
that the aluminum and arsenic content of the resulting aqueous solution was
reduced to 0 mg/L.
