U.S. patent application number 15/560077 was filed with the patent office on 2018-03-22 for water-purifying agent and water purification method.
The applicant listed for this patent is Dexerials Corporation. Invention is credited to Takanori Fujita, Masahiko Ito, Ryu Shimada.
Application Number | 20180079665 15/560077 |
Document ID | / |
Family ID | 57004486 |
Filed Date | 2018-03-22 |
United States Patent
Application |
20180079665 |
Kind Code |
A1 |
Ito; Masahiko ; et
al. |
March 22, 2018 |
Water-Purifying Agent and Water Purification Method
Abstract
Provided is a water-purifying agent formed of a granulated
product including a mixture of a plant powder and a polymeric
flocculant, wherein a surface of the granulated product includes a
coated portion in which the plant powder is coated with the
polymeric flocculant and a non-coated portion in which the plant
powder is not coated with the polymeric flocculant.
Inventors: |
Ito; Masahiko; (Tokyo,
JP) ; Shimada; Ryu; (Tokyo, JP) ; Fujita;
Takanori; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Dexerials Corporation |
Tokyo |
|
JP |
|
|
Family ID: |
57004486 |
Appl. No.: |
15/560077 |
Filed: |
March 16, 2016 |
PCT Filed: |
March 16, 2016 |
PCT NO: |
PCT/JP2016/058410 |
371 Date: |
September 20, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C02F 2101/103 20130101;
C02F 1/5227 20130101; B01D 21/01 20130101; C02F 2101/22 20130101;
C02F 1/5263 20130101; C02F 2101/14 20130101; C02F 2101/20 20130101;
C02F 2101/203 20130101; C02F 1/56 20130101 |
International
Class: |
C02F 1/52 20060101
C02F001/52; C02F 1/56 20060101 C02F001/56; B01D 21/01 20060101
B01D021/01 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 30, 2015 |
JP |
2015-069266 |
Claims
1. A water-purifying agent, comprising: a granulated product that
comprises a mixture of a plant powder and a polymeric flocculant,
wherein a surface of the granulated product comprises a coated
portion in which the plant powder is coated with the polymeric
flocculant and a non-coated portion in which the plant powder is
not coated with the polymeric flocculant.
2. The water-purifying agent according to claim 1, wherein a ratio
of an area of the coated portion to a total of the area of the
coated portion and an area of the non-coated portion is from 10%
through 90%.
3. The water-purifying agent according to claim 1, wherein a ratio
of an area of the coated portion to a total of the area of the
coated portion and an area of the non-coated portion is from 30%
through 70%.
4. The water-purifying agent according to claim 1, wherein the
plant powder is of any one of Corchorus olitorius, mulukhiya,
Japanese mustard spinach, Japanese honewort, potherb mustard, and
spinach.
5. The water-purifying agent according to claim 4, wherein the
plant powder is of Corchorus olitorius.
6. The water-purifying agent according to claim 4, wherein the
Corchorus olitorius is "intermediate jute No. 4" under 2013, which
is an identification number in Institute of Bast Fiber Crops,
Chinese Academy of Agricultural Sciences.
7. The water-purifying agent according to claim 1, wherein a median
diameter of the water-purifying agent is 150 micrometers or
greater.
8. The water-purifying agent according to claim 1, wherein the
polymeric flocculant is a polyacrylamide.
9. The water-purifying agent according to claim 1, wherein the
water-purifying agent is produced by a producing method that
comprises: mixing the plant powder and the polymeric flocculant and
kneading the plant powder and the polymeric flocculant with
addition of moisture, to obtain a kneaded product; shaping the
kneaded product into a sheet shape by a stretching method, to
obtain a sheet-shaped shaped product; drying the sheet-shaped
shaped product, to obtain a dried sheet; and pulverizing the dried
sheet.
10. A water purification method, comprising: dissolving the
water-purifying agent according to claim 1 in water to obtain a
dispersion liquid of the plant powder and the polymeric flocculant,
and feeding the dispersion liquid to wastewater including an
inorganic unnecessary substance to remove the inorganic unnecessary
substance in the wastewater.
11. The water purification method according to claim 10, wherein
the wastewater is wastewater including the inorganic unnecessary
substance that contains at least any one of nickel, fluorine, iron,
copper, zinc, chromium, arsenic, cadmium, tin, and lead.
12. The water purification method according to claim 11, comprising
feeding the dispersion liquid to the wastewater after subjecting at
least any one of inorganic ions selected from the group consisting
of a nickel ion, a fluorine ion, an iron ion, a copper ion, a zinc
ion, a chromium ion, an arsenic ion, a cadmium ion, a tin ion, and
a lead ion contained in the inorganic unnecessary substance to an
insolubilizing treatment.
Description
TECHNICAL FIELD
[0001] The present invention relates to a plant-derived
water-purifying agent used for purification of water such as
industrial wastewater and a water purification method using the
water-purifying agent.
BACKGROUND ART
[0002] In recent years, a large amount of waste liquids containing
environmentally hazardous substances such as metal ions and
fluorine ions as inorganic ions have been generated in the
processes for producing various products in plants.
[0003] Meanwhile, regulations on effluence of such inorganic ions
have been becoming gradually strict. In order to comply with the
effluent control, an inorganic ion removing method that can
effectively remove inorganic ions from wastewater including the
inorganic ions and can be carried out as easily and inexpensively
as possible is demanded.
[0004] Hitherto, as the method for removing impurity ions from, for
example, wastewater from plants, for example, a flocculating
precipitation method, an ion-exchange method, a method for
adsorption to an adsorbent such as activated charcoal, an
electrosorption method, and a magnetic adsorption method have been
proposed.
[0005] For example, as the flocculating precipitation method, there
has been proposed a method of performing a step of adding a base to
wastewater in which heavy metal ions are dissolved, to make the
wastewater basic, insolubilize at least part of the heavy metal
ions, and form a suspended solid matter, a step of adding an
inorganic flocculant to the wastewater to make the suspended solid
matter set and settle, a step of adding a polymeric flocculant to
the wastewater to turn the suspended solid matter to a macrofloc,
and an adsorbing step of passing the wastewater through an
adsorption layer containing a cation exchanger formed of a leafy
vegetable such as mulukhiya and Japanese mustard spinach (see,
e.g., PTL 1).
[0006] There has also been proposed a flocculating method of
flocculating and separating particles in a suspension by means of
mixed use or combined use of a flocculant containing at least any
one of mulukhiya, a dried product of mulukhiya, and an extract of
mulukhiya with a polymeric flocculant (see, e.g., PTL 2).
[0007] The more the amount of the wastewater to be purified, the
more the amount of an unnecessary substance included in the
wastewater, or the more the kinds of unnecessary substances
included in the wastewater, the more necessary it is to build an
automated system for feeding a purifying agent necessary for the
wastewater purification treatments.
[0008] Device automation is an important issue for performing
high-speed, stable purification treatments, and it is desired to
provide a water-purifying agent suitable for being fed to an
automated purification apparatus.
CITATION LIST
Patent Literature
[0009] PTL 1: Japanese Patent Application Laid-Open (JP-A) No.
2011-194385
[0010] PTL 2: JP-A No. 11-114313
SUMMARY OF INVENTION
Technical Problem
[0011] However, the method described in PTL 1 takes effort and time
because the flocculating step using a flocculant and the adsorbing
step using a cation exchanger are separate. The method described in
PTL 2 takes time until inorganic ions are reduced to equal to or
lower than the desired concentration. Neither of the methods is
satisfactory in water purifying performance.
[0012] Furthermore, the methods described in these documents are
not at all intended for automated devices for wastewater
purification treatments. The purifying agents described in the
documents are not suitable for being fed to automated system
devices.
[0013] Hence, it has been desired to provide a water-purifying
agent that is capable of reducing inorganic ions to equal to or
lower than a desired concentration in a predetermined time, has an
excellent water purifying performance, and can be suitably used in
an automated system device.
[0014] The present invention aims for solving the various problems
in the related art and achieving the object described below. That
is, the present invention has an object to provide a
water-purifying agent that has an excellent water purifying
performance and can be suitably used in an automated wastewater
purification apparatus.
Solution to Problem
[0015] Means for solving the above problems are as follows.
<1> A water-purifying agent, including:
[0016] a granulated product including a mixture of a plant powder
and a polymeric flocculant,
[0017] wherein a surface of the granulated product includes a
coated portion in which the plant powder is coated with the
polymeric flocculant and a non-coated portion in which the plant
powder is not coated with the polymeric flocculant.
<2> The water-purifying agent according to <1>,
[0018] wherein a ratio of an area of the coated portion to a total
of the area of the coated portion and an area of the non-coated
portion is from 10% through 90%.
<3> The water-purifying agent according to <1> or
<2>,
[0019] wherein a ratio of an area of the coated portion to a total
of the area of the coated portion and an area of the non-coated
portion is from 30% through 70%.
<4> The water-purifying agent according to any one of
<1> to <3>,
[0020] wherein the plant powder is of any one of Corchorus
olitorius, mulukhiya, Japanese mustard spinach, Japanese honewort,
potherb mustard, and spinach.
<5> The water-purifying agent according to <4>,
[0021] wherein the plant powder is of Corchorus olitorius.
<6> The water-purifying agent according to <4> or
<5>,
[0022] wherein the Corchorus olitorius is "intermediate jute No. 4"
under 2013, which is an identification number in Institute of Bast
Fiber Crops, Chinese Academy of Agricultural Sciences.
<7> The water-purifying agent according to any one of
<1> to <6>,
[0023] wherein a median diameter of the water-purifying agent is
150 micrometers or greater.
<8> The water-purifying agent according to any one of
<1> to <7>,
[0024] wherein the polymeric flocculant is a polyacrylamide.
<9> The water-purifying agent according to any one of
<1> to <8>,
[0025] wherein the water-purifying agent is produced by a producing
method including a kneading step of mixing the plant powder and the
polymeric flocculant and kneading the plant powder and the
polymeric flocculant with addition of moisture, to obtain a kneaded
product, a stretching/sheet forming step of shaping the kneaded
product into a sheet shape by a stretching method, to obtain a
sheet-shaped shaped product, a drying step of drying the
sheet-shaped shaped product, to obtain a dried sheet, and a
pulverizing step of pulverizing the dried sheet.
<10> A water purification method, including:
[0026] dissolving the water-purifying agent according to any one of
<1> to <9> in water to obtain a dispersion liquid of
the plant powder and the polymeric flocculant, and feeding the
dispersion liquid to wastewater including an inorganic unnecessary
substance to remove the inorganic unnecessary substance in the
wastewater.
<11> The water purification method according to
<10>,
[0027] wherein the wastewater is wastewater including the inorganic
unnecessary substance that contains at least any one of nickel,
fluorine, iron, copper, zinc, chromium, arsenic, cadmium, tin, and
lead.
<12> The water purification method according to <11>,
including
[0028] feeding the dispersion liquid to the wastewater after
subjecting at least any one of inorganic ions selected from the
group consisting of a nickel ion, a fluorine ion, an iron ion, a
copper ion, a zinc ion, a chromium ion, an arsenic ion, a cadmium
ion, a tin ion, and a lead ion contained in the inorganic
unnecessary substance to an insolubilizing treatment.
Advantageous Effects of Invention
[0029] The present invention can solve the various problems in the
related art, achieve the object described above, and provide a
water-purifying agent that has an excellent water purifying
performance and can be suitably used in an automated wastewater
purification apparatus.
BRIEF DESCRIPTION OF DRAWINGS
[0030] FIG. 1 is a scanning electron microscopic image (SEM image)
illustrating an example of a surface of a granulated product;
[0031] FIG. 2 is a scanning electron microscopic image (SEM image)
illustrating an example of a surface of a granulated product;
and
[0032] FIG. 3 is a scanning electron microscopic image (SEM image)
illustrating an example of a surface of a granulated product.
DESCRIPTION OF EMBODIMENTS
(Water-Purifying Agent)
[0033] A water-purifying agent of the present invention is formed
of a granulated product including a mixture of a plant powder and a
polymeric flocculant.
[0034] The surface of the granulated product includes a coated
portion in which the plant powder is coated with the polymeric
flocculant and a non-coated portion in which the plant powder is
not coated with the polymeric flocculant.
[0035] The water-purifying agent of the present invention
satisfying the requirement described above is a water-purifying
agent that has an excellent water purifying performance and can be
suitably used in an automated wastewater purification
apparatus.
[0036] The present inventors have earnestly studied a
water-purifying agent including a plant powder in order to provide
a water-purifying agent having an excellent water purifying
performance. As a result, it has been found that a granulated
product obtained by kneading a plant powder and a polymeric
flocculant has an excellent water purifying performance if the
surface of the granulated product includes a coated portion in
which the plant powder present on the surface of the granulated
product is coated with the polymeric flocculant and a non-coated
portion in which the plant powder present on the surface of the
granulated product is not coated with the polymeric flocculant.
[0037] The reason is uncertain but considered as follows.
[0038] The target of the present invention is industrial
wastewater, e.g., industrial wastewater including an inorganic
unnecessary substance such as nickel, fluorine, iron, copper, zinc,
chromium, arsenic, cadmium, tin, and lead. For removal of the
inorganic unnecessary substance from the wastewater (also described
as purification of water), the present invention insolubilizes
inorganic ions such as nickel ion, fluorine ion, and iron ion
contained in the inorganic unnecessary substance, to form a
suspended solid matter (also referred to as microfloc in the
present invention), and flocculates and settles the microfloc, to
separate the solid from the liquid. In such purification of water,
use of a granulated product formed of a plant powder and a
polymeric flocculant is considered to:
[0039] (i) promote formation of the microfloc of the inorganic ions
included in the wastewater by the polymeric flocculant;
[0040] (ii) increase an effect of adsorbing the inorganic ions
included in the wastewater by the plant powder; and
[0041] (iii) increase an effect of adsorbing the microfloc by pores
present in the plant powder.
[0042] Hence, it can be assumed that if the void (porous) portions
of the fiber of the plant material are not at all coated with the
polymeric flocculant (if the coated portion is not formed), the
plant particles rapidly absorb water and settle, failing to exhibit
the adsorbing effect described above, whereas that if the porous
portions are completely coated with the polymeric flocculant (if
the non-coated portion is not formed), the plant powder particles
having the cation exchange function cannot sufficiently have
contact with the wastewater, failing to exhibit the effects of (ii)
and (iii) described above.
[0043] Accordingly, it is considered that the granulated product
defined in the present invention and including both of the coated
portion and the non-coated portion on the surface can exhibit an
excellent water purifying performance.
[0044] The granulated product defined in the present invention and
including the coated portion and the non-coated portion on the
surface can be produced by a producing method described below.
[0045] The granulated product defined in the present invention,
produced by the producing method described below, and satisfying
the requirement described above exhibits an excellent settling
resistance, and exhibits favorable values as viscosity and bulk
specific gravity (see the results of Examples below). The fact that
the granulated product exhibits these physical properties is also
considered a factor for exhibiting an excellent water purifying
performance.
[0046] The granulated product defined in the present invention
exhibits a favorable value as fluidity index as presented in
Examples below, has an excellent fluidity, and can be suitably used
in an automated purification apparatus.
[0047] A specific constitution of the water-purifying agent will be
described below.
<Plant>
[0048] The plant is not particularly limited so long as the plant
is a plant that can flocculate and separate unnecessary substances
(e.g., nickel, copper, and fluorine) included in wastewater.
Examples of the plant include Corchorus olitorius, mulukhiya,
Japanese mustard spinach, Japanese honewort, potherb mustard, and
spinach. It is preferable to use powders of these plants, because
powders of these plants have a high cation exchange function and
have pores that can adsorb a microfloc included in the wastewater
including the inorganic ions.
[0049] Any part of the plant such as leaf, stalk, and root may be
used.
[0050] Among the plants, Corchorus olitorius and mulukhiya are
preferable, and Corchorus olitorius, which exhibited favorable
results in Examples below, is more preferable.
[0051] Among Corchorus olitorius, "intermediate jute No. 4" under
2013, which is an identification number in Institute of Bast Fiber
Crops, Chinese Academy of Agricultural Sciences, is particularly
preferable.
[0052] "Intermediate jute No. 4" has the following
characteristics.
[0053] Kind of agricultural product: jute
[0054] Source of breed: a product obtained by breeding a hybridized
F1 generation between Hunan jute No. 3 and 0-4(1), with Hunan jute
No. 3.
[0055] Characteristics: Intermediate jute No. 4 is a typical type
of Corchorus olitorius jute that has green cylindrical stalks,
scattered acicular leaves, green petioles, a small angle from the
main stalk, lateral buds and stipules, green calyces, and a
cylindrical shape of a long fruit. A 5-locule species is a
late-maturing breed.
<Polymeric Flocculant>
[0056] The polymeric flocculant is not particularly limited so long
as the polymeric flocculant exhibits an effect of removing the
inorganic unnecessary substance included in the wastewater, like
the plant described above. Examples of the polymeric flocculant
include polyacrylamide (PAM), a salt obtained by partially
hydrolyzing polyacrylamide, polyamine, sodium alginate, sodium
polyacrylate, and CMC sodium salt. Among these polymeric
flocculants, polyacrylamide is preferable for use. As the
polyacrylamide, for example, commercially available products FLOPAN
AN 905, FLOPANAN 926, and FLOPAN AN 956 (available from SNF Japan
Co., Ltd.) can be used.
<Granulated Product of Mixture of Plant Powder and Polymeric
Flocculant>
[0057] The mixing ratio between the plant powder and the polymeric
flocculant is in the range of from 10:90 through 90:10 on a mass
ratio basis.
[0058] The granulated product exhibits the following
characteristics.
<<Surface Condition>>
[0059] The surface of the granulated product includes a coated
portion in which the plant powder is coated with the polymeric
flocculant and a non-coated portion in which the plant powder is
not coated with the polymeric flocculant.
[0060] The surface of the granulated product has a porous form in
which pores are present and many holes are opened due to the fiber
structure of the plant powder.
[0061] The coated portion is formed by the polymeric flocculant
intruding into the pores of the fiber of the plant material and the
pores present on the surface of the granulated product being coated
with the polymeric flocculant.
[0062] States of the coated portion and the non-coated portion will
be described with reference to FIG. 1 to FIG. 3.
[0063] FIG. 2 is a SEM image of a surface of a granulated product
on which pores are not coated with the polymeric flocculant,
illustrating a state that the pores are not coated with the
polymeric flocculant, and the coated portion is not formed, i.e.,
the area of the coated portion accounts for 0% of the surface area
of the granulated product.
[0064] FIG. 3 is a SEM image of a surface of a granulated product
on which pores are completely coated with the polymeric flocculant,
illustrating a state that the non-coated portion is not formed,
i.e., the area of the coated portion accounts for 100% of the
surface area of the granulated product.
[0065] As compared, FIG. 1 is a SEM image illustrating an example
of the granulated product defined in the present invention. FIG. 1
illustrates a state that the coated portion and the non-coated
portion are present in a mixed state on the surface of the
granulated product. FIG. 1 illustrates a state that the area of the
coated portion accounts for 50% of the surface area of the
granulated product.
[0066] In order for the granulated product to sufficiently exert
the effects of (i) to (iii) described above, it is important that
at least part of the plant powder present on the surface of the
granulated product be not coated with the polymeric flocculant to
form a non-coated portion. In the present invention, the area of
the coated portion accounts for less than 100%, preferably equal to
or less than 90% of the surface area of the granulated product.
Meanwhile, in order for the granulated product to sufficiently
exert the effects of (i) to (iii) described above, it is also
important that at least part of the plant powder present on the
surface of the granulated product be coated with the polymeric
flocculant to form a coated portion. In the present invention, the
area of the coated portion accounts for greater than 0%, preferably
equal to or greater than 10% of the surface area of the granulated
product.
[0067] In the present invention, the area of the coated portion is
measured in the manner described below, and the ratio of the area
of the coated portion in the surface area is calculated according
to the formula (1) below.
Area of coated portion/(area of coated portion+area of non-coated
portion) (1)
[0068] In the present invention, the ratio of the area of the
coated portion to the total of the area of the coated portion and
the area of the non-coated portion is preferably from 10% through
90% and more preferably from 30% through 70%.
[0069] In order to form a coated portion and a non-coated portion
on the surface of the granulated product, it is preferable to
produce the granulated product by the producing method described
below. Particularly, when the producing method is employed, it is
possible to adjust the ratio between the coated portion and the
non-coated portion. The producing method will be described
below.
[0070] The areas of the coated portion and the non-coated portion
can be obtained by a method described below based on SEM
images.
[Method for Measuring Ratio of Coated Portion in Surface Area]
[0071] As illustrated in FIG. 1, the portions at which a porous
structure conforming to the oblique fibrous structure can be
observed are non-coated portions that are not coated with the
polymeric flocculant, and the portions at which a porous structure
conforming to an oblique fibrous structure cannot be observed are
coated portions that are coated with the polymeric flocculant.
Hence, the SEM image is observed to classify the portions as the
corresponding portions, and measure the areas of the respective
portions. As represented by the formula (1) above, the ratio of the
area of the coated portions to the total of the area of the coated
portions and the area of the non-coated portions is calculated as
the ratio of the coated portions in the surface area.
[0072] The measurement is performed on a region having an image
brightness that allows discrimination of the fibrous structure of
the plant described above. For example, in a case where it is
impossible to recognize the surface structure because of being
displayed darkly for such a reason as that the surface of the
granulated product is dented, or in a case where it is difficult to
recognize the surface structure because the image is dark, as is
observed also in FIG. 1 to FIG. 3 from place to place, such regions
are excluded from the measurement.
<<Median Diameter>>
[0073] The median diameter of the granulated product defined in the
present invention is preferably 150 micrometers or greater and more
preferably 200 micrometers or greater but 900 micrometers or
less.
[0074] When the median diameter is less than 150 micrometers,
quantitativity of the granulated product by a feeder is poor
because the granulated product has a poor fluidity.
[0075] When the median diameter is 900 micrometers or less, there
is no risk of clogging ducts provided in, for example, a pulverizer
or an automatic feeder. Therefore, the granulated product can be
favorably used in an automatic purification apparatus.
[0076] The median diameter (also referred to as d50) is a diameter
of a particle plotted at 50% of all particles when the granulated
product is plotted by the size of particle diameter (i.e., a
particle diameter that makes particles having larger diameters and
particles having smaller diameters equal in quantity). In the
present invention, a particle diameter refers to volume particle
diameter.
[0077] The median diameter can be measured with a commercially
available measuring instrument such as MASTERSIZER 2000 (available
from Malvern Instruments Ltd.).
<<Fluidity Index>>
[0078] A Carr's fluidity index of the water-purifying agent of the
present invention obtained by measuring 3 items of the
water-purifying agent, which are an angle of repose, a degree of
compression, and a spatula angle, is preferably 45 or greater and
more preferably 52.5 or greater.
[0079] Here, an angle of repose, a degree of compression, and a
spatula angle refer to an angle of repose, a degree of compression,
and a spatula angle raised as measurement items for Carr's fluidity
index (R. L. Carr. `Evaluating Flow Properties of Solids` Chemical
Engineering, Jan. 18, 1965).
[0080] The angle of repose, the degree of compression, and the
spatula angle can be measured with, for example, various types of
commercially available powder physical property measurement
devices. Specifically, for example, these properties can be
measured with POWDER TESTER PT-N TYPE (available from Hosokawa
Micron Corporation) according to methods described below.
[0081] For obtaining a fluidity index based on the obtained angle
of repose, degree of compression, and spatula angle, it is possible
to use a standard generally known as Carr's fluidity index.
[0082] In the present invention, the Carr's fluidity index table
generated by Hosokawa Micron Corporation based on the
aforementioned Chemical Engineering, Jan. 18. (1965) on page 166
and page 167 under authorization of R. L. Carr and McGraw-Hill Inc.
and made known to the public by Hosokawa Micron Corporation is
used.
[0083] Table 1 below presents a table of fluidity indices with
respective to 3 items related with the present invention, which are
an angle of repose, a degree of compression, and a spatula angle,
among evaluation items of Carr's fluidity index. Based on Table 1,
an index for an angle of repose, an index for a degree of
compression, and an index for a spatula angle corresponding to
measured values of the angle of repose, the degree of compression,
and the spatula angle respectively are obtained, and these index
values are totaled. In the present invention, the total value is
used as the fluidity index of the water-purifying agent.
TABLE-US-00001 TABLE 1 Fluidity index Angle of repose Degree of
compression Spatula angle Degree Index % Index Degree Index 67.5 to
75 <26 25 <6 25 <26 25 26 to 29 24 6 to 9 23 26 to 30 24
30 22.5 10 22.5 31 22.5 60 to 67 31 22 11 22 32 22 32 to 34 21 12
to 14 21 33 to 37 21 35 20 15 20 38 20 52.5 to 59.5 36 19.5 16 19.5
39 19.5 37 to 39 18 17 to 19 18 40 to 44 18 40 17.5 20 17.5 45 17.5
45 to 52 41 17 21 17 46 17 42 to 44 16 22 to 24 16 47 to 59 16 45
15 25 15 60 15 30 to 44.5 46 14.5 26 14.5 61 14.5 47 to 54 12 27 to
30 12 62 to 74 12 55 10 31 10 75 10 15 to 29.5 56 9.5 32 9.5 76 9.5
57 to 64 7 33 to 36 7 77 to 89 7 65 5 37 5 90 5 0 to 13.5 66 4.5 38
4.5 91 4.5 (14.5) 67 to 89 2 39 to 45 2 92 to 99 2 90 0 >45 0
>99 0
[0084] The angle of repose, the degree of compression, and the
spatula angle can be obtained in the manners described below.
[Measurement of Angle of Repose (.degree.)]
[0085] The angle of repose (.degree.) can be measured with POWDER
TESTER PT-N TYPE (available from Hosokawa Micron Corporation)
according to an injection method described below.
[0086] A measurement sample is let to fall onto a circular
receptacle table through a funnel and form a mountain-shaped layer.
An angle formed between a slope of the mountain and a horizontal
plane is measured.
[Measurement of Degree of Compression (.degree.)]
[0087] Da (compressed apparent specific gravity) and Db (loose
apparent specific gravity) for the degree of compression can be
measured with POWDER TESTER PT-N TYPE (available from Hosokawa
Micron Corporation).
[0088] A dedicated cap is attached on top of a 100 cc stainless
steel cup. A sample (from 150 cc through 200 cc) is loaded into the
cup. The specific gravity of the sample after the sample is
vibrated by being let to fall from a height of 2 cm repeatedly 180
times is measured as Da.
[0089] The sample (100 cc) is calmly loaded into the 100 cc
stainless steel cup, and the specific gravity of the sample at the
time is measured as Db.
[0090] The Da and Db values are assigned into the formula (2)
below.
Degree of compression (%)={(Da-Db)/Da}.times.100 (2)
[0091] Da (compressed apparent specific gravity): a specific
gravity of powder, grains, or both of powder and grains measured
after the powder, the grains, or both of the powder and the grains
loaded in a container having a predetermined capacity is/are
vibrated by being let to fall from a height of 2 cm repeatedly 180
times
[0092] Db (loose apparent specific gravity): a specific gravity of
powder, grains, or both of powder and grains measured when the
powder, the grains, or both of the powder and the grains is/are
calmly loaded into a container having a predetermined capacity
[Measurement of Spatula Angle (.degree.)]
[0093] The spatula angle (.degree.) can be measured with POWDER
TESTER PT-N TYPE (available from Hosokawa Micron Corporation).
[0094] A sample is deposited on a rectangular spatula put
horizontally in a manner to conceal the spatula. A cross-sectional
angle (A) of a mountain formed when the spatula is slowly lifted up
vertically, and a cross-sectional angle (B) of a mountain formed
after the mountain of the powder is collapsed by application of a
certain impact are measured. These values are assigned into the
formula (3) below to calculate the spatula angle (.degree.).
Spatula angle (.degree.)={(A+B)/2} (3)
[0095] The water-purifying agent of the present invention produced
by the producing method described below exhibits a favorable result
as the fluidity index as presented in Examples below.
<<Bulk Specific Gravity>>
[0096] The water-purifying agent of the present invention produced
by the producing method described below exhibits a favorable value
as bulk specific gravity, and has a small variation in the bulk
specific gravity value.
[0097] The bulk specific gravity of the water-purifying agent is
0.3 g/cm.sup.3 or greater but 0.8 g/cm.sup.3 or less.
[0098] The bulk specific gravity can be measured with POWDER TESTER
PT-N TYPE (available from Hosokawa Micron Corporation).
[0099] A sample (100 cc) is calmly poured into a 100 cc stainless
steel cup, and the specific gravity of the sample at the time is
measured as the bulk specific gravity.
[0100] Variation of the bulk specific gravity (variation being a
ratio of a difference between a maximum and a minimum of the bulk
specific gravity to the minimum of the bulk specific gravity) of
the water-purifying agent is preferably 4.5% or less.
[0101] The variation of the bulk specific gravity can be obtained
in the manner described below.
[0102] The water-purifying agent, which is the measurement sample,
is poured into a bag having a certain size (e.g., a 700
mm.times.500 mm plastic bag), and the opening of the bag is
heat-sealed. Here, the amount of the water-purifying agent to be
poured into the bag is considered in a manner to secure a space in
the bag enough for the water-purifying agent to move freely in a
subsequent vibrating operation. Next, the water-purifying agent put
in the bag is vibrated up and down so as not to break the
granulated product. Subsequently, the sample is taken out from the
bag from 5 positions including the top and bottom portions of the
bag, and the bulk specific gravity of each is measured.
[0103] The maximum and the minimum of the bulk specific gravity are
recorded, and the variation is obtained according to the
calculation of the formula (4) below based on the maximum and the
minimum.
(Difference between maximum and minimum of bulk specific
gravity/minimum of bulk specific gravity).times.100 (4)
<Method for Producing Granulated Product>
[0104] The granulated product defined in the present invention is
produced by a producing method including a kneading step of mixing
the plant powder and the polymeric flocculant and kneading the
plant powder and the polymeric flocculant with addition of
moisture, to obtain a kneaded product, a stretching/sheet forming
step of shaping the kneaded product into a sheet shape by a
stretching method, to obtain a sheet-shaped shaped product, a
drying step of drying the sheet-shaped shaped product, to obtain a
dried sheet, and a pulverizing step of pulverizing the dried
sheet.
[0105] Further, a classifying step of classifying the granulated
product by sieving may be provided after the pulverizing step.
[0106] The present inventors have experimentally confirmed that an
excessively strong shear force (shear) applied to the kneaded
product during granulation caused the polymeric flocculant to
intrude into the porous portions of the fiber of the plant material
to have the plant powder on the surface coated with the polymeric
flocculant.
[0107] Hence, in order to control the shear to be applied to the
kneaded product, the granulated product was produced by a
granulation method based on the stretching/sheet forming step. As a
result, it was found possible to produce a granulated product on
which a coated portion and a non-coated portion were present.
Furthermore, it is also possible to control the ratio of the coated
portion in the surface area by the granulation method based on the
stretching/sheet forming step.
[0108] In the stretching/sheet forming step, the kneaded product is
gradually stretched by a roller, and a sheet-shaped shaped product
having a predetermined thickness is formed stepwise. According to
this method, the shaped product can be produced with the viscosity
of the kneaded product maintained favorably. This is considered to
effectively act in the production of the granulated product defined
in the present invention.
[0109] In the kneading step, a dry plant is coarsely pulverized and
then finely pulverized, to obtain a plant powder having a desired
size. Subsequently, the obtained plant powder and the polymeric
flocculate are mixed and kneaded with addition of moisture.
[0110] Here, as the adding amount of water, it is preferable to add
water having a mass of about, for example, 3 times as large as the
total mass of the mixed plant powder and polymeric flocculant.
[0111] Kneading is performed with a mixer, for example, a vertical
mixer such as a planetary mixer, with the rotation number and time
set within predetermined ranges.
[0112] The rotation number and time of kneading by the mixer can be
appropriately set in consideration of the kind of the plant and
conditions such as the mixing ratio between the plant powder and
the polymeric flocculant. For example, the rotation number is
preferably from 20 rpm through 150 rpm, and the time is preferably
from 5 minutes through 25 minutes.
[0113] In the stretching/sheet forming step, the obtained kneaded
product may be stretched by a stretching method using a roller
until the thickness becomes from 2 mm through 30 mm, preferably
about 10 mm, to be shaped into a sheet shape.
[0114] It is possible to control the coated state of the plant
powder on the surface of the granulated product, by controlling the
shear to be applied to the kneaded product. For example, in the
kneading step, it is possible to control the coated state of the
plant powder on the surface of the granulated product, by varying
the conditions such as the mixing ratio between the plant powder
and the polymer, the amount of water to be added, the mixing speed
(the rotation number of the mixer during kneading), and the mixing
time (the kneading time by the mixer) in the kneading step, or by
varying the stretching conditions in the stretching/sheet forming
step.
[0115] In the drying step, the obtained shaped product may be dried
with a multistage hot air dryer at a temperature of from 80 degrees
C. through 150 degrees C. for from 2 hours through 12 hours.
[0116] In the pulverizing step, pulverization may be performed with
a pulverizer such as a jet type ultrafine grinder until the median
diameter falls within a range of from 150 micrometers through 900
micrometers.
[0117] In the classifying step, the pulverized powder may be
subjected to a classifier, e.g., a vibration sieve machine or a
cartridge-type sieve machine, to classify the granulated product of
which particle diameter is within a predetermined range, so that
the median diameter may be within a range of from 150 micrometers
through 900 micrometers.
(Water Purification Method)
[0118] A water purification method of the present invention
dissolves the water-purifying agent of the present invention
described above in water to obtain a dispersion liquid of the plant
powder and the polymeric flocculant, and feeds the dispersion
liquid to wastewater to remove an inorganic unnecessary substance
included in the wastewater.
[0119] Examples of the inorganic unnecessary substance include an
inorganic unnecessary substance that contains at least any one of
nickel, fluorine, iron, copper, zinc, chromium, arsenic, cadmium,
tin, and lead.
[0120] The water purification method of the present invention will
be specifically described.
[0121] Inorganic ions such as nickel ion, fluorine ion, and iron
ion contained in the inorganic unnecessary substance included in
the wastewater are subjected to an insolubilizing treatment, to
form a microfloc. The dispersion liquid prepared as an aqueous
solution of from 0.1% through 0.2% is fed to the wastewater. The
microfloc is flocculated and settled, and a precipitate separated
by settling is removed. In this way, the wastewater is
purified.
[0122] In the insolubilizing treatment, for example, a base is
added to the wastewater to make the wastewater basic and
insolubilize the inorganic ions. Further, after the base is added,
it is possible to add a polymeric flocculant alone. In this case,
addition of a polymeric flocculant alone before addition of the
water-purifying agent of the present invention can increase the
floc size of the microfloc in the wastewater.
EXAMPLES
[0123] The present invention will be described below by way of
Examples. The present invention should not be construed as being
limited to these Examples.
Example 1
[0124] As wastewater used for experiment, an aqueous solution (800
g) including nickel ion (50 mg/L) was prepared by dissolving nickel
sulfate hexahydrate in pure water (virtual wastewater).
[0125] Next, caustic soda was supplied to the wastewater to adjust
pH to 10, and the wastewater was stirred to insolubilize nickel. A
nickel ion concentration in a supernatant liquid of the wastewater
was 2 mg/L.
<Water-Purifying Agent>
[0126] Next, "shrunk spinach produced in Maebashi of Gunma
Prefecture" was used as the plant, and polyacrylamide (PAM) was
used as the polymeric flocculant. A granulated product 1 was
obtained by a producing method described below, and the granulated
product 1 was used as a water-purifying agent 1.
<<Method for Producing Water-Purifying Agent>>
[0127] Water was added to the plant powder and the polymeric
flocculant in a mass that was 3 times as large as the mass of a
solid content, which was the total of the plant powder and the
polymeric flocculant, to obtain a kneaded product (plant
powder+polymeric flocculant+water=30 kg). The kneaded product was
put in a planetary mixer (available from Aicohsha Manufacturing
Co., Ltd., MIXER ACM-110, with a capacity of 110 L) and kneaded
with a shear applied under conditions including a rotation number
of 150 rpm and a mixing time of 20 minutes.
[0128] Using a press machine (available from Komatsu Industries
Corp., a 45 t press machine), the obtained kneaded product was
stretched with a roller to produce a sheet-shaped shaped product
having a thickness of about 10 mm.
[0129] The shaped product was dried with a multistage hot air dryer
(available from Shichiyo Co., Ltd., a rack oven) at 120 degrees C.
for 3 hours and further at 150 degrees C. for 2 hours.
[0130] Next, the dried sheet was pulverized with a jet-type
ultrafine grinder (available from Masuko Sangyo Co., Ltd., CEREN
MILLER) such that the median diameter would be 400 micrometers.
[0131] The median diameter was measured with MASTERSIZER 2000
(available from Malvern Instruments Ltd.).
[0132] The pulverized powder was subjected to a classifier (a
vibration sieve machine available from Dalton Corporation) to
remove (cut) particles less than 200 micrometers and greater than
900 micrometers by sieving, in order to use only particles having a
particle diameter in the range of from 200 micrometers through 900
micrometers.
[0133] In this way, the granulated product 1 was obtained and used
as the water-purifying agent 1.
<Characteristic Evaluation>
[0134] The area of the coated portion of the granulated product 1
was measured by the measuring method described above. As a result,
50% of the surface area of the granulated product was the coated
portion.
[0135] Next, the water-purifying agent 1 was added to the
wastewater in an amount of 7 mg/L relative to a solid content, and
the wastewater was stirred. As the method for measuring the "solid
content", the solid content can be obtained by back calculation
from a slurry concentration in the wastewater measured with a
moisture meter.
[0136] The wastewater to which the water-purifying agent 1 was
added was moved to a settling tank and then left to stand still.
The condition of the wastewater was visually observed at every 1
hour.
[0137] The time at which the wastewater was obviously confirmed to
be separated into 2 layers, namely a supernatant liquid and a
precipitate was measured as a settling time.
[0138] The supernatant liquid was picked for ion concentration
measurement with LAMBDA (.LAMBDA.) 9000 (available from Kyoritsu
Chemical-Check Lab., Corp.).
[0139] The result was evaluated according to the criteria described
below as water purifying performance.
[Evaluation Criteria for Water Purifying Performance]
[0140] A: Less than 1.0 mg/L (equal to or less than the detection
limit)
[0141] B: 1.0 mg/L or greater but less than 1.5 mg/L
[0142] C: 1.5 mg/L or greater but less than 2.0 mg/L
[0143] D: 2.0 mg/L or greater
[0144] The evaluation result of Example 1 is presented in Table
2-1. In Table 2-1, the plant powder 1 represents "shrunk spinach
produced in Maebashi of Gunma Prefecture" and PAM represents a
polyacrylamide (the same applies in Table 2-2 to Table 2-4).
Example 2
[0145] A granulated product 2 was produced in the same manner as in
Example 1, except that unlike in Example 1, Corchorus olitorius
(produced in Guangzhou of China) was used as the plant, and the
rotation number of the mixer and the time in the kneading step were
changed to 80 rpm and 15 minutes.
[0146] Using a water-purifying agent 2 formed of the granulated
product 2, the characteristic of the water-purifying agent was
evaluated in the same manner as in Example 1. The evaluation result
of Example 2 is presented in Table 2-1. In Table 2-1, the plant
powder 2 represents "Corchorus olitorius (produced in Guangzhou of
China)".
Example 3
[0147] A granulated product 3 was produced in the same manner as in
Example 2, except that unlike in Example 2, Corchorus olitorius,
which was "intermediate jute No. 4" under 2013, which was an
identification number in Institute of Bast Fiber Crops, Chinese
Academy of Agricultural Sciences was used as the plant.
[0148] Using a water-purifying agent 3 formed of the granulated
product 3, the characteristic of the water-purifying agent was
evaluated in the same manner as in Example 1. The evaluation result
of Example 3 is presented in Table 2-1. In Table 2-1, the plant
powder 3 represents "intermediate jute No. 4".
Example 4
[0149] A granulated product 4 was produced in the same manner as in
Example 3, except that unlike in Example 3, the rotation number of
the mixer and the time in the kneading step were changed to 150 rpm
and 5 minutes.
[0150] Using a water-purifying agent 4 formed of the granulated
product 4, the characteristic of the water-purifying agent was
evaluated in the same manner as in Example 1. The evaluation result
of Example 4 is presented in Table 2-1.
Example 5
[0151] A granulated product 5 was produced in the same manner as in
Example 3, except that unlike in Example 3, the rotation number of
the mixer and the time in the kneading step were changed to 100 rpm
and 10 minutes.
[0152] Using a water-purifying agent 5 formed of the granulated
product 5, the characteristic of the water-purifying agent was
evaluated in the same manner as in Example 1. The evaluation result
of Example 5 is presented in Table 2-1.
Example 6
[0153] A granulated product 6 was produced in the same manner as in
Example 3, except that unlike in Example 3, the rotation number of
the mixer and the time in the kneading step were changed to 50 rpm
and 20 minutes.
[0154] Using a water-purifying agent 6 formed of the granulated
product 6, the characteristic of the water-purifying agent was
evaluated in the same manner as in Example 1. The evaluation result
of Example 6 is presented in Table 2-2.
Example 7
[0155] A granulated product 7 was produced in the same manner as in
Example 3, except that unlike in Example 3, the rotation number of
the mixer and the time in the kneading step were changed to 20 rpm
and 25 minutes.
[0156] Using a water-purifying agent 7 formed of the granulated
product 7, the characteristic of the water-purifying agent was
evaluated in the same manner as in Example 1. The evaluation result
of Example 7 is presented in Table 2-2.
Example 8
[0157] A granulated product 8 was produced in the same manner as in
Example 3, except that unlike in Example 3, the classifying step
was not performed.
[0158] Using a water-purifying agent 8 formed of the granulated
product 8, the characteristic of the water-purifying agent was
evaluated in the same manner as in Example 1. The evaluation result
of Example 8 is presented in Table 2-2.
Example 9
[0159] A granulated product 9 was produced in the same manner as in
Example 3, except that unlike in Example 3, a polyamine was used as
the polymeric flocculant.
[0160] Using a water-purifying agent 9 formed of the granulated
product 9, the characteristic of the water-purifying agent was
evaluated in the same manner as in Example 1. The evaluation result
of Example 9 is presented in Table 2-2.
Example 10
[0161] As wastewater used for experiment, an aqueous solution (800
g) including fluorine ion (2,500 mg/L) was prepared by dissolving
potassium fluoride in pure water (virtual wastewater).
[0162] Next, calcium chloride (8.6 mg/L) was added to the
wastewater, and the wastewater was stirred while adding sodium
hydroxide to adjust pH to from 7.5 through 9.0, to insolubilize
fluorine. By this operation, the fluorine aqueous solution was
separated into a supernatant liquid including a microfloc and a
precipitate.
[0163] At the time, the ion concentration in the supernatant liquid
of the wastewater was 10 mg/L.
[0164] Using the water-purifying agent 3 formed of the granulated
product 3, the characteristic of the water-purifying agent was
evaluated in the same manner as in Example 3 except that the
wastewater described above was used. The evaluation result of
Example 10 is presented in Table 2-2.
Example 11
[0165] As wastewater used for experiment, an aqueous solution (800
g) including iron ion (200 mg/L) was prepared by dissolving ferric
chloride hexahydrate in pure water (virtual wastewater).
[0166] Next, the wastewater was stirred while adding sodium
hydroxide to adjust pH to from 6.5 through 9.0, to insolubilize
iron.
[0167] At the time, the ion concentration in the supernatant liquid
of the wastewater was 2 mg/L.
[0168] Using the water-purifying agent 3 formed of the granulated
product 3, the characteristic of the water-purifying agent was
evaluated in the same manner as in Example 3 except that the
wastewater described above was used. The evaluation result of
Example 11 is presented in Table 2-3.
Example 12
[0169] As wastewater used for experiment, an aqueous solution (800
g) including copper ion (100 mg/L) was prepared by dissolving
copper sulfate pentahydrate in pure water (virtual wastewater).
[0170] Next, the wastewater was stirred while adding sodium
hydroxide to adjust pH to from 7.0 through 8.0, to insolubilize
copper.
[0171] At the time, the ion concentration in the supernatant liquid
of the wastewater was 2 mg/L.
[0172] Using the water-purifying agent 3 formed of the granulated
product 3, the characteristic of the water-purifying agent was
evaluated in the same manner as in Example 3 except that the
wastewater described above was used. The evaluation result of
Example 12 is presented in Table 2-3.
Example 13
[0173] As wastewater used for experiment, an aqueous solution (800
g) including zinc ion (100 mg/L) was prepared by dissolving zinc
nitrate hexahydrate in pure water (virtual wastewater).
[0174] Next, the wastewater was stirred while adding sodium
hydroxide to adjust pH to from 9.0 through 9.5, to insolubilize
zinc.
[0175] At the time, the ion concentration in the supernatant liquid
of the wastewater was 5 mg/L.
[0176] Using the water-purifying agent 3 formed of the granulated
product 3, the characteristic of the water-purifying agent was
evaluated in the same manner as in Example 3 except that the
wastewater described above was used. The evaluation result of
Example 13 is presented in Table 2-3.
Example 14
[0177] As wastewater used for experiment, an aqueous solution (800
g) including chromium ion (100 mg/L) was prepared by dissolving
potassium dichromate in pure water (virtual wastewater).
[0178] Next, the wastewater was stirred while adding sodium
hydroxide to adjust pH to from 6.0 through 7.5, to insolubilize
chromium.
[0179] At the time, the ion concentration in the supernatant liquid
of the wastewater was 5 mg/L.
[0180] Using the water-purifying agent 3 formed of the granulated
product 3, the characteristic of the water-purifying agent was
evaluated in the same manner as in Example 3 except that the
wastewater described above was used. The evaluation result of
Example 14 is presented in Table 2-3.
Example 15
[0181] As wastewater used for experiment, an aqueous solution (800
g) including arsenic ion (10 mg/L) was prepared by dissolving
diarsenic trioxide in pure water (virtual wastewater).
[0182] Next, ferric chloride (65 mg/L) and calcium chloride (354
mg/L) were added to the wastewater, and the wastewater was stirred
while adding sodium hydroxide to adjust pH to from 8.0 through 9.5,
to insolubilize arsenic.
[0183] At the time, the ion concentration in the supernatant liquid
of the wastewater was 0.05 mg/L.
[0184] Using the water-purifying agent 3 formed of the granulated
product 3, the characteristic of the water-purifying agent was
evaluated in the same manner as in Example 3 except that the
wastewater described above was used.
[0185] However, in Example 15, after the settling time was measured
in the same manner as in Example 3, the supernatant liquid was
picked and concentrated with an evaporator until the volume became
1/100, and then the ion concentration in the supernatant liquid was
measured. As for arsenic ion, an ion concentration that would be
judged as a favorable result and would be evaluated as grade A was
0.01 mg/L or less. The evaluation result of Example 15 is presented
in Table 2-3.
Example 16
[0186] A granulated product 16 was produced in the same manner as
in Example 3, except that unlike in Example 3, the median diameter
in the dried sheet pulverization was changed to 150
micrometers.
[0187] Using a water-purifying agent 16 formed of the granulated
product 16, the characteristic of the water-purifying agent was
evaluated in the same manner as in Example 1. The evaluation result
of Example 16 is presented in Table 2-3.
Example 17
[0188] A granulated product 17 was produced in the same manner as
in Example 3, except that unlike in Example 3, the median diameter
in the dried sheet pulverization was changed to 100
micrometers.
[0189] Using a water-purifying agent 17 formed of the granulated
product 17, the characteristic of the water-purifying agent was
evaluated in the same manner as in Example 1. The evaluation result
of Example 17 is presented in Table 2-3.
Comparative Example 1
[0190] An experiment was conducted in the same manner as in Example
1, except that unlike in Example 1, a granulated product was not
used and a polymeric flocculant was only used.
[0191] Using a comparative water-purifying agent 1 of Comparative
Example 1, the characteristic of the water-purifying agent was
evaluated in the same manner as in Example 1. The evaluation result
of Comparative Example 1 is presented in Table 2-4.
Comparative Example 2
[0192] An experiment was conducted in the same manner as in Example
1, except that unlike in Example 1, a granulated product was not
used, and a plant powder and a polymeric flocculate were used alone
respectively.
[0193] Using a comparative water-purifying agent 2 of Comparative
Example 2, the characteristic of the water-purifying agent was
evaluated in the same manner as in Example 1. The evaluation result
of Comparative Example 2 is presented in Table 2-4.
Comparative Example 3
[0194] A comparative granulated product 3 of Comparative Example 3
was produced in the same manner as in Example 3, except that unlike
in Example 3, the rotation number of the mixer and the time in the
kneading step were changed to 20 rpm and 30 minutes.
[0195] Using a comparative water-purifying agent 3 formed of the
comparative granulated product 3, the characteristic of the
water-purifying agent was evaluated in the same manner as in
Example 1. The evaluation result of Comparative Example 3 is
presented in Table 2-4.
TABLE-US-00002 TABLE 2-1 Ex. Ex. Ex. Ex. Ex. Item 1 2 3 4 5 Plant
powder 1 2 3 3 3 Polymeric flocculant PAM PAM PAM PAM PAM Area (%)
of coated portion 50 50 50 10 30 Target ion Ni Ni Ni Ni Ni Median
diameter (micrometer) 400 400 400 400 400 Settling time (hour) 96
96 96 4 78 Water purifying performance C B A C B (96 hours
later)
TABLE-US-00003 TABLE 2-2 Ex. Ex. Ex. Ex. Ex. Item 6 7 8 9 10 Plant
powder 3 3 3 3 3 Polymeric flocculant PAM PAM PAM Polyamine PAM
Area (%) of coated portion 70 90 50 50 50 Target ion Ni Ni Ni Ni F
Median diameter (micrometer) 400 400 400 400 400 Settling time
(hour) 92 24 96 96 96 Water purifying performance B C C B A (96
hours later)
TABLE-US-00004 TABLE 2-3 Ex. Ex. Ex. Ex. Ex. Ex. Ex. Item 11 12 13
14 15 16 17 Plant powder 3 3 3 3 3 3 3 Polymeric flocculant PAM PAM
PAM PAM PAM PAM PAM Area (%) of coated 50 50 50 50 50 50 50 portion
Target ion Fe Cu Zn Cr As Ni Ni Median diameter 400 400 400 400 400
150 100 (micrometer) Settling time (hour) 96 96 96 96 96 100 100
Water purifying A A A A A B C performance (96 hours later)
TABLE-US-00005 TABLE 2-4 Comp. Comp. Comp. Item Ex. 1 Ex. 2 Ex. 3
Plant powder -- 3 3 Polymeric flocculant PAM PAM PAM Area (%) of
coated portion -- 0 100 Target ion Ni Ni Ni Median diameter
(micrometer) 400 400 400 Settling time (hour) -- 1 100 Water
purifying performance D D D (96 hours later)
Example 18
[0196] The angle of repose, degree of compression, and spatula
angle of the granulated products 1 to 9 obtained in Examples 1 to 9
were measured by the methods described above, to calculate the
fluidity index based on Table 1 presented above.
[0197] Fluidity was evaluated according to the criteria described
below. As a result, all of the granulated products 1 to 9 obtained
in Examples 1 to 9 exhibited a good result of A.
[0198] A: From 52.5 through 75
[0199] B: From 45 through 52
[0200] C: From 0 through 44.5
Example 19
[0201] The granulated product 3 obtained in Example 3 exhibited the
physical properties presented in Table 3 below. These properties
are considered effective properties that will lead to a good result
when the granulated product is used as a water-purifying agent. The
reason why a water-purifying agent exhibiting such good physical
properties was obtained is considered largely attributable to the
production by the granulation method based on the stretching/sheet
forming step.
TABLE-US-00006 TABLE 3 Granulated product 3 Settling resistance 96
hours Solubility viscosity (mPa S) 250 Bulk specific gravity
(g/cm.sup.3) From 0.33 through 0.39
[0202] In Table 3, the settling resistance (hour) refers to the
settling time described in 1 above. The bulk specific gravity was
measured by the method described above. The solution viscosity
(mPaS) was measured with a B-type viscometer.
[0203] From the results of Examples 1 to 19, it was confirmed that
the water-purifying agent of the present invention was a
water-purifying agent that was able to lower an inorganic ion
concentration to equal to or lower than a desired concentration in
a short time, and was excellent in water purifying performance.
Furthermore, the water-purifying agent of the present invention had
a good fluidity and did not clog an automatic feeder and a
quantitative machine. It was confirmed that the water-purifying
agent of the present invention was a water-purifying agent that
could be suitably used in an automated system device.
* * * * *