1. A method for water processing comprising: charging into water for processing a high-molecular flocculant having a molecular structure portion comprised of an inorganic and/or organic amine compound added to at least a portion of cyano groups contained in a high-molecular material.

2. The method for water processing as claimed in claim 1 wherein said high-molecular flocculant is used in conjunction with at least one of a nonionic high-molecular flocculant, an anionic high molecular flocculant and a cationic high-molecular flocculant.

3. The method for water processing as claimed in claim 2 comprising: sequentially charging said high-molecular flocculant and theanionic high-molecular flocculant into the water for processing.

4. A method for processing water as claimed in any of claim 1 comprising a high-molecular material at least a portion groups of which has been converted into carbamoyl groups.

5. The method for water processing as claimed in claim 4, wherein said high-molecular flocculant is used in conjunction with at least one of a nonionic high-molecular flocculant, an anionic highmolecular flocculant and a cationic high-molecular flocculant.

6. The method for water processing as claimed in claim 5 comprising: sequentially charging said high-molecular flocculant and the anionic high-molecular flocculant into the water for processing.

7. The method for water processing as claimed in claim 6 comprising: charging into the water for processing the flocculant a further portion of carbamoyl groups of which have been converted into carboxylic groups or salts thereof.

8. A method for water processing substantially as hereinbefore described with reference to the accompanying drawings.

TITLE OF THE INVENTION
High-Molecular Flocculant, Method for Producing the Flocculant and
Water-Treatment Method Employing the Flocculant
BACKGROUND OF THE INVENTION
This invention relates to a high-molecular flocculant rendered
water-soluble by conversion of cyano groups contained in a highmolecular
material, a method for producing the flocculant, and
method for efficiently processing water using the flocculant.
Description of the Related Art
In the field of processing waste water, a flocculant is used as
a reagent for causing aggregation and precipitation of micro-sized
particles dispersed in waste water. In the waste water, such as
industrial waste water, it is a frequent occurrence that mud or highmolecular
impurities . are dispersed as colloidal particles. The
flocculant serves for aggregating these colloidal particles for
purifying the polluted water. '.
Of the wide variety of known flocculants, those having a
molecular structure of a long chain and exhibiting high
hydrophilicity are high-molecular flocculants which are used
extensively because addition of only a limited amount thereof to the
colloidal particles leads to significant aggregating effects. The highmolecular
flocculants are classified into an anionic type, a cationic
type and a nonionic type depending on static charges on dissolution
in water. Since a majority of colloidal particles are charged to the
positive or negative polarity, extremely large floes are formed, to
lower the t u r b i d i t y h i g h l y e f f i c i e n t l y by properly selecting the highmolecular
flocculants depending on the polarity of the static
charges.
In the field of manufacturing industrial products, highmolecular
material, containing acrylonitrile as a monomeric unit, are
used extensively. Among the high-molecular materials containing
acrylonitrile, there are polystyrene based resins, typified by nitrile
resins, ABS (acrylonitrile- butadiene- styrene resins), SAN resins
(styrene- acrylonitrile resin), AAS resins- (acrylonitrile- acrylstyrene
resins) and ACS . resins (acrylonitrile- chlorinated
polyethylene- styrene resin), acrylic fibers obtained on spinning a
polymer having acrylonitrile as a main monomeric unit, and NBR
(acrylonitrile- butadiene rubber, also termed nitrile rubber).
• . " A resin molded product, containing acrylonitrile as monomeric
units, is superior in stiffness, dimensional stability and workability
and hence is used frequently' as a cover or a casing for various
usages, a casing for an electric appliance or a car or as a material
for components.
The acrylic fibers are lightweight, bulky and is excellent in
heat insulating properties, skin touch feeling, weatherability and
resiliency, so that they are used extensively for apparel alone or as
a mixture with other fibers, such as wool or cotton.
The nitrile rubber exhibits superior weatherability against oils,
such as fuel oil, machine oil or a lube oil, so that it is used as a
fuel hose, oil seal or a belt and in particular for car use.
The a c r y l o n i t r i l e containing high-molecular material, used in
a wide variety of i n d u s t r i a l products, produces a large quantity of
waste materials in the course of fabrication of the industrial
products or on discarding of the used-up industrial products. The
waste high-molecular materials are generally disposed of by
techniques such as incineration, earth filling or re-melting. The
former two technique belongs to discarding, while the later
technique belongs to recycling.
The above-mentioned disposal techniques for the highmolecular
material suffer from specified problems.
First, the incineration is accompanied by the problem of
evolution of toxic gases during combustion of the waste material.
That is, highly toxic cyan gas (HCN) is evolved due to cyano
groups (-CN) contained in the acrylonitrile monomer unit and
which constitutes one of side chains of the polymer. Another factor
contributing to incineration difficulties is susceptibility to
conversion into incombustible matter as a result of carbonization.
Re-melting is a technique of heat-melting the recovered waste
material for re-molding, and represents an effective technique
insofar as thermoplastic resins are concerned. However, the material
tends to be deteriorated in quality due to lowering in the molecular
weight or oxidation, while being liable to mixing of foreign matter,
such as dust and dirt. If waste materials of different originating
points are processed collectively, technical and cost problems are
raised, such as the necessity of re-coloring due to coexistence of
various coloring agents.
Thus, discarding by land filling is nowadays thought to be
most proper measures. However, selection and procurement of the
proper site for a processing plant is becoming difficult from year to
year, while the problem of environmental p o l l u t i o n cannot be evaded
without difficulties.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method
for manufacturing a high-molecular flocculants having superior
flocculating properties by a simple and safe manner using the highmolecular
material containing cyano groups as a starting material
and a method for effective disposal of waste water employing this
high-molecular flocculant.
The high-molecular flocculant of the present invention,
proposed for accomplishing the above object, is such a flocculant
in which at least a portion of cyano groups ( - C N ) contained in the
high-molecular material is converted to impart water-solubility to
enable the use of the material as a flocculant.
Specifically, in one aspect, the present invention provides a
high-molecular flocculant having a molecular structure portion
comprised of an organic and/or inorganic amino compound added to
at least a portion of cyano groups contained in a high-molecular
material.
In another aspect, the present invention provides a highmolecular
flocculant in which at least a portion of cyano groups
contained in a high-molecular material has been converted into
carbamoyl groups.
The former flocculant can be prepared by reacting the cyano
group containing high-molecular material with an amino compound,
while the latter can be prepared by hydrolyzing the cyano group
containing high-molecular material.
In particular, if a used-up waste material from some other
process is used as a high-molecular material for use as a starting
material, resources can be exploited effectively by recycling thus
contributing to environment conservation.
The high-molecular flocculant, thus obtained, can be injected
into water for processing for water processing as a cationic or
nonionic type high-molecular flocculant. It may also be used in
conjunction with other nonionic, anionic or cationic high-molecular
flocculant.
It is seen from above that the high-molecular flocculant
according to the present invention is obtained as a result of
hydrophilicity-imparting modification of the high-molecular material
containing cyano groups, in particular cyano groups originating from
acrylonitrile. Since the high-molecular material is likely to be
produced in large quantities as industrial wastes, the present
invention is highly effective in reducing toxic waste materials and
effective utilization of resources.
Moreover, since this modification of the high-molecular
material is achieved by addition of an amino compound or by a
hydrolytic reaction, there is caused no problem such as emission of
toxic gases during incineration thus evading the problem of new
environmental pollution in the course of processing of waste
materials. In addition, the high-molecular flocculant obtained as a
result of processing of the waste materials exhibits superior
properties in connection with the rate of flocculation, turbidity of
the supernatant liquid or in the water content of the cake.
Therefore, use of the high-molecular flocculant obtained as a result
of processing of the waste materials, for water processing, leads to
re-utilization of the usually discarded waste materials, thus
contributing not only to reduction of the toxic waste materials and
effective utilization of resources, but to environmental conservation
through purification of waste water.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig.l illustrates the mechanism for addition reaction, salt
forming reaction and hydrolysis in connection with manufacture of
a high-molecular flocculant of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
The high-molecular flocculant of the present invention is
obtained by introducing a highly hydrophilic molecular structure into
at least a portion of cyano groups inherently contained in the highmolecular
material or by subsequently carrying out salt formation or
hydrolysis in case of necessity for adjusting water-solubility or
flocculating properties. If it is desired to impart sufficient
hydrophilicity to the yielded high-molecular flocculant or to
preclude yielding of hydrogen cyanide with a view to safe waste
discarding, it is preferred that the majority of cyano groups shall
be converted into a highly hydrophilic molecular structure portion.
The highly hydrophilic molecular structure portion may be
exemplified by a molecular structure portion having added inorganic
or organic amino compounds or carbamoyl groups formed by
hydrolysis of cyano groups.
As the amino compounds added to the cyano group in the
former case, there are, for example, inorganic amino compounds,
such as ammonia, hydrazine or hydroxylamine, and organic amino
compounds, such as primary or secondary amines in which one or
two hydrogen atoms of ammonia are substituted by hydroxy groups.
The carbon skeleton of the hydrocarbon group may be saturated or
non-saturated, of a chain or cyclic structure, straight-chained or
branched. It is also possible for hetero elements other than carbon,
hydrogen or nitrogen, such as oxygen, sulfur or halogens, to be
contained in the skeleton of the hydrocarbon group.
Examples of the organic amino compounds include primary or
secondary amines, substituted by C1-C12 saturated or unsaturated
chained or cyclic hydrocarbon groups, primary or secondary amines
containing two or more amino groups in one molecule and the
aforementioned primary and secondary amines containing hetero
atoms other than nitrogen in the molecule.
The primary and secondary amines containing two or more
amino groups in one molecule may be enumerated by alkylene
diamines, such as methylene diamine, ethylene diamine, trimethyl
diamine (diamino propane), tetramethylene diamine (diamino butane),
pentametylene diamine (diamino pentane), hexamethylene diamine
(diamino hexane) or hexamethylene diamine (diaminoheptane), Nalkyl
alkylene diamines, such as N-methyl methylene diamine, Nmethyl
ethylene diamine, N-benzyl ethylene diamine, N-methyl-1, 3-
diamino propane, N-butyl-1, 3- diamino propane, N, - dimethyl- 1,
3- diamino propane or N-butyl- 1, 3- diamino propane, alkylene
polyamines (not less than three substituents), such as diethylene
triamine, triethylene tetramine, tetraethylene pentamine,
pentaethylene hexamine, polyethylene imine or piperidine and cyclic
polyamines, such as 1, 2- diamino cyclohexane, xylylene diamine and
diamino diphenylmethane.
The amino compounds containing hetero atoms other than
nitrogen in the molecule may be enumerated by hydroxyl
alkylamines, such as ethanolamine, propanolamine, butanolamine and
pentanolamine. Ethane thiolamine may also be used.
Although there is no limitation to the amino compounds,
polyamine compounds, in particular ethylene diamine or 1, 3-propane
diamine, are preferably used for reaction with the high-molecular
material since the polyamine compound can yield an imidazoline ring
by reaction with cyano groups.
The molecular structure portion, yielded by addition of an
organic or inorganic amino compound, has an imidamino or
imidazoline structure, and exhibits basicity due to the lone electron
pair on the nitrogen atom.
If this n i t r o g e n atom is linked by coordinate bond to a proton
furnished from the inorganic or organic acid, the nitrogen atom is
charged positively to yield an acid salt. An inorganic acid, such as
sulfuric acid, chlorosulfonic acid, chloric acid, nitric acid or
phosphoric acid may be used. As an organic acid, acetic acid, lactic
acid, phthalic acid or phenols may be used.
If a halogenated hydrocarbon or sulfuric acid ester is given the
molecular structure portion, the nitrogen atom of the molecular
structure portion is linked to the hydrocarbon group of sulfuric acid
ester or the halogenated hydrocarbon so as to be charged positively
to yield a quaternary amine salt having the halogen as paired ions.
The halogenated hydrocarbon used at this time mat be enumerated
by methyl chloride or benzyl chloride, while the sulfuric acid ester
may be enumerated by dimethyl sulfide or diethyl sulfide.
These acid salts and quaternary ammonium salts exhibit high
water solubility.
On the other hand, the latter (hydrophilic groups such as
carbamoyi group) is yielded by replacing at least a portion of the
«
strongly hydrophobic cyan group inherently contained in the highmolecular
material by a hydrophilic group, that is a carbamoyi group
(CONH2) or by a carboxyl group (-COOH) or salts thereof (-COOX,
where X is a cation).
This carbamoyi group or the carboxyl group is obtained by
conversion of a functional group by a hydrolytic reaction. This
conversion of the functional group occurs in the sequence of a cyan
group - a. carbamoyl group - a carboxyl group (or a salt thereof).
As a matter of course, it is necessary for the cyano group to
be contained in the high-molecular material as a starting material
for the high-molecular flocculant of the present invention in a form
allowing addition thereto of ammonia or an amino compound or in
a form allowing for substitution by a hydrophilic group. A highmolecular
material containing acrylonitrile (CH2=CH-CN) is
preferred because the cyano group is linked s a side chain of the
polymer molecule.
The molecular structure portions yielded on addition, of
ammonia, hydroxylamine, ethylene diamine, primary alkyl amine and
ethanolamine to the cyano group of the acrylonitrile monomer unit
are collectively shown in Fig.l, along with structures obtained on
yielding of the imidazoline ring by the action of ethylene diamine,
acid salts, quaternary ammonium salts yielded on hydrolysis.
The above-mentioned high-molecular material may also be
copolymers with other monomeric units (copolymers) without being
limited to acrylonitrile homopolymers. These other monomeric units
may be enumerated by one or more selected from the group
consisting of acrylic acid, methacrylic acid, acrylic acid ester,
methacrylic acid esters, butadiene, isoprene, chloroprene, vinyl
chloride, acrylic amide, methacrylic amide, vinyl acetate, styrene,
cc-methyl styrene, ethylene, propylene, fumaric anhydride, maleic
anhydride, itaconic anhydride, N-vinyl pyrrolidone and vinyl
pyridine. The side chain of t h e ester bond of the acrylic acid ester
and methacrylic acid ester is preferably constituted by saturated or
unsaturated hydrocarbons having 1 to 10 carbon atoms.
Among representative high-molecular materials, obtained on
combining acrylonitrile with the above-mentioned other polymers,
there are, for example, acrylic fibers, nitrile fibers,-SAN resins
(styrene- acrylonitrile resins), acrylonitrile- butadiene resins,
acrylonitrile- butadiene- styrene resins, acrylonitrile- butadieneacrylic
resins, acrylonitrile- chlorinated polyethylene resin, nitrile
rubber and acrylonitrile- butadiene rubber.
Meanwhile, if the above-mentioned high-molecular material is
an acrylonitrile homopolymer, the content of the cyano groups is
100 mol%. However; if the high-molecular material is the
acrylonitrile copolymer, the content of the cyano groups naturally
is varied depending on the content of the acrylonitrile monomer
unit. If the content of the cyano groups is varied, the upper limit
of the number of mols of the molecular structure portion yielded by
the addition reaction of the amino compound and further the upper
limit of the structure of hydrolysis yielded by changes in the salt
the molecular structure portion can yield or in the molecular
structure portion are changed. Similarly, if the content of the cyano
groups is changed, the upper limit of the number of mols of the
carbamoyl group introduced later, the carboxylic group introduced
in place of the carbamoyl group on or the salts thereof are changed.
That is, if the content of the cyano groups is inherently small,
the high-molecular flocculant of the present i n v e n t i o n cannot e x h i b i t
high h y d r o p h i l i c i t y or flocculating properties.
That is, according to the present invention, it is preferred
that the cyano groups be contained in the high-molecular material
in an amount corresponding to not less than 15 mol% of the total
monomer units, that is that the content of the acrylonitrile monomer
units be not less than 15 mol%. This amount is preferably not less
than 25 mol%.
Meanwhile, the high-molecular material has the weight average
molecular weight (Mw) of approximately not less than 5000. If the
molecular weight is lower than this limit value, the flocculating
properties as the high-molecular flocculant tend to be lost.
The high-molecular material, as the starting material for the
high-molecular flocculant according to the present invention, may,
of course, be a newly prepared material, that is a so-called virgin
material. However, from the viewpoint of effective utilization of
natural resources and prevention of environmental destruction, it is
particularly desirable to use a used-up waste material.
These waste materials may be exemplified by, for example, a
casing, a cover or a vessel used in electric appliances, cars,
stationery, measurement instruments, building materials or in
cosmetics. The waste materials may be in the form of a mixture
with other waste materials. Examples of these other waste materials
include synthetic or natural fibers, such as polyester, nylon,
polyurethane, polyamides, polyphenylene ether, polycarbonates,
polyphenylene sulfide, polyethylene terephthalate, polybutylene
terephthalate, silk, wool or cotton, occasionally containing a variety
of additives, such as coloring agents, stabilizers, water retention
agents, combustion retardants, plasticizers or fillers.
If the above-mentioned other waste materials are used in
conjunction, the content of these other waste materials is preferably
not more than 60 wt%. If the content exceeds 60 wt%, the effect of
the functional groups is strongly demonstrated such that desired
water solubility is occasionally not imparted to the yielded highmolecular
flocculant.
Thus, although the waste materials may be those recovered
from factories, retail stores or homes, the waste materials from
factories or retail stores, where waste materials of the unitary
composition are likely to be produced in larger quantities, are more
desirable than those recovered from holes and in which foreign
waste materials tend to be mixed more readily.
Turning to the method for producing the high-molecular
flocculant of the present invention, if the high-molecular flocculant
has a molecular structure portion comprised of organic and/or
inorganic amino compounds added to at least a portion of the cyano
groups contained in the high-molecular material, it is sufficient if
the above-mentioned acrylonitrile homopolymer or copolymer is used
as a starting material and is reacted with the organic and/or
inorganic amino compounds.
This reaction can be carried out by directly injecting the
starting material into the amino compounds. After the end of the
reaction, it is possible to pour a solvent in which the highmolecular
flocculant is not soluble, such as acetone, into the
reaction mixture in large quantities to re-precipitate the product.
Alternatively, the reaction can be carried out in an organic
solvent, which may be a C5 to C20 aliphatic chain hydrocarbon
and/or cyclic hydrocarbon, Cl to C4 halogenated hydrocarbons,
dichlorobenzene, aromatic hydrocarbons, ethers, ketones, esters, or
non-protonic polar solvents, such as dimethyl sulfoxide (DMSO),
dimethyl formamide (DMF), tetrahydrofuran (THF) or diox,ane. If
the organic solvent is used, the reaction product may be obtained
as an aqueous solution by adding water to the reaction system and
distilling off the solvent after the end of the reaction.
During the reaction, sulfur-based catalysts, such as sulfur
powders, thiourea or thioacetoamide, are preferably used.
Although there is no limitation to the concentration of the
amino compound during the reaction, it is preferably not lower than
approximately 10%. If this concentration is too low, the speed of
the addition reaction tends to be lowered, or the reaction of
addition tends to be retarded. There is also no upper limit to the
above concentration. If the reaction of addition is carried out by
injecting a small amount of the high-molecular material into ethylene
diamine, the concentration of ethylene diamine is approximately
100%.
The reaction temperature for the reaction of addition differs
with the type of the high-molecular material used as the starting
material, type of the catalyst used, type of the solvent used for the
reaction system and with whether or not the solvent is used. If the
reaction temperature is 0 to 150°C, the reaction is allowed to
proceed with practically acceptable speed and controllability. If the
temperature is lower than this range, the reaction speed is lowered
thus possibly lowering the production efficiency. Conversely, if the
temperature is higher than the above range, the high-molecular
material tends to be lowered in molecular weight to lower the
efficiency as the flocculant. This temperature range is preferably 20
to 120°C and most preferably 40 to 80PC.
As for the reaction time duration, which depends on the type
of the amino compound used, the reaction time of 30 minutes to 50
hours can give a target product with a practically acceptable yield.
If the reaction time duration is shorter than this range, sufficient
modification cannot be achieved. However,, if once the chemical
equilibrium is reached, prolongation of the reaction time has no
meaning.
If, in the present invention, hydrolysis is to occur after the
addition reaction of the amino compound, it can be carried out by
acid hydrolysis employing an acid catalyst or alkali hydrolysis
employing a basic catalyst.
As the acidic catalyst for acidic hydrolysis, inorganic acids,
such as sulfuric acid, sulfuric anhydride, fuming sulfuric acid,
chlorosulfonic acid, hydrochloric acid, nitric acid or phosphoric
acid, may be used. These inorganic acids may be used in conjunction
with inorganic peroxides, such as aqueous hydrogen peroxide, in
order to promote the hydrolytic reaction.
As the basic catalyst for the alkaline hydrolysis, hydroxides,
hydrogen carbonates, carbonates or acetates of Li, Na, K or NH4
may be used.
In any type of the alkaline hydrolysis, the high-molecular
material may be directly injected into inorganic acids, or into an
aqueous alkaline solution of an inorganic base. Alternatively, the
hydrolysis may be carried out using the same solvent as that used
for the above-mentioned reaction of addition. The catalyst
concentration, reaction temperature or the reaction time for
hydrolysis may be set equivalently to the respective ranges
discussed in connection with the above-mentioned reaction of
addition.
The high-molecular flocculant, resulting from the above
process, is of the nonionic type in the stage in which it has
acquired the molecular structure portion directly after addition of
the amino compound, and is of the strong cation type on converting
this molecular structure portion into an acid salt or a quaternary
* ammonium salt. That is, with the above-described manufacturing
method of the high-molecular flocculant, it is possible to produce
flocculants of the nonionic type and the cationic type by judiciously
selecting and combining the stages of the progress of the reaction
of addition and the salt-forming reaction.
For converting the cyano group for i n t r o d u c i n g carbamoyl
groups, carboxylic groups or salts thereof, the aforementioned
a c r y l o n i t r i l e homopolymers or copolymers are used as the starting
material, that is as a basic material for hydrolysis.
The hydrolysis is roughly classified into an acidic hydrolysis
employing an acidic catalyst and hydrolysis employing the basic
catalyst. Any of these hydrolysis types may be used in the present
invention.
As the acidic catalyst for the above-mentioned acidic
hydrolysis, inorganic acids, such as sulfuric acid, sulfuric anhydride,
fuming sulfuric acid, chlorosulfonic acid, hydrochloric acid, nitric
acid or phosphoric acid, may be used. These inorganic acids may be
used in conjunction with inorganic peroxides, such as aqueous
hydrogen peroxide, in order to promote the hydrolytic reaction.
Since the acidic hydrolysis of the high-molecular material containing
cyano groups is satisfactory in controllability, the reaction itself
can be carried out in one step by properly selecting the reaction
temperature and the reaction time so that a desired content of the
carbamoyl groups will be achieved.
Although there is no particular limitation to the concentration
of the inorganic acid, it is preferably set to approximately not less
than 10%. If this concentration is too low, it may occur that the
reaction speed of the hydrolysis is lowered or the hydrolytic
reaction cannot proceed sufficiently. There is also no particular
limitation to the upper limit of the concentration. If hydrolysis is
carried out by charging a small quantity of the high-molecular
material into sulfuric acid, the concentration of the inorganic acid
is approximately 100%.
As the basic catalyst for the alkaline hydrolysis, inorganic
bases, such as hydroxides, hydrogen carbonates, carbonates or
acetates of Li, Na, K or NH4 may be used.
However, alkaline hydrolysis is in need of a higher temperature
than in the case of the acidic hydrolysis described above, such that,
if this temperature condition is once achieved, the reaction proceeds
speedily. The result is that the yielded high-molecular flocculant is
lowered in molecular weight, or the reaction of conversion of the
cyan group through a carbamoyl group to a carboxylic group or its
salt proceeds at a time to render it difficult to control the
introduced amount of ionic groups, that is carboxylic anions.
Therefore, the basic catalyst is not used from the outset of the
reaction, and is preferably used in the second stage in case of the
two-stage hydrolysis. That is, acidic hydrolysis by the acidic
catalyst is first carried out in the first stage to prescribe
substantially the amount of the carbamoyl groups introduced and
alkaline hydrolysis is then carried out in the second stage in order
to convert a further portion of the carbamoyl groups into carboxylic
groups or salt thereof.
In any type of the alkaline hydrolysis, the high-molecular
material may be directly injected into inorganic acids, or into an
aqueous alkaline solution of an inorganic base.
Alternatively, the above hydrolysis may be carried out in an
organic solvent, which may be a C5 to C20 aliphatic chain
hydrocarbon and/or cyclic hydrocarbon, Cl to C4 halogenated
hydrocarbons, aromatic hydrocarbons, ethers, ketones, esters, or
non-protonic polar solvents, such as dimethyl sulfoxide, dimethyl
formamide, tetrahydrofuran or dioxane.
The method for ultimate recovery of the high-molecular
flocculant in the above-described manufacturing method differs with
the system of the hydrolytic reaction. If, for example, the highmolecular
material is directly charged into inorganic acid, it is
possible to pour a solvent in which the high-molecular flocculant is
not soluble, such as acetone, into the reaction mixture in large
quantities to re-precipitate the product. If the solvent is used
during hydrolysis, the reaction product may be obtained as an
aqueous solution by neutralizing an excess acidic catalyst or a basic
catalyst and by distilling off the solvent.
With the reaction temperature for hydrolysis ranging between
0 to 180°C, the reaction is allowed to proceed with practically
satisfactory speed and controllability, although the reaction
temperature differs with the types of the high-molecular material
used as a starting material, the catalyst constituting the reaction
system, and the presence or absence of the solvent. The reaction
temperature is more preferably 20 to 150°C and most preferably 60
to 130°C.
The high-molecular flocculant, obtained as described above, is
of the nonionic type by introducing the carbamoyl group and is of
the anionic type by substituting carboxylic acid or carboxylates for
a portion of the carbamoyl group.
Since the high-molecular flocculant of the present invention is
at any rate of the nonionic, cationic or anionic type, it may be used
for water processing in accordance with the usual method of
exploiting the nonionic, cationic or anionic type high-molecular
flocculant. Alternatively, the high-molecular flocculant of the
present invention may be used in conjunction with various other
flocculants.
The usable nonionic high-molecular flocculants may be
exemplified by a synthetic system, such as polyacrylic amide,
polymethacrylic amide or polyoxyethylene, or natural systems, such
as starch, guar gum, gelatine or the like sugar, or proteins.
The cationic high-molecular flocculants include quaternary
products of dialkyl aminoalkyl (meth)acrylate, where the
quaternarification agents include methyl chloride, dimethyl suJfate
and benzyl chloride, or acid salts thereof, where acid salts include
inorganic acid salts, such as hydrochlorates or sulfates, and organic
acid salts', such as acetates, polymers or copolymers thereof with
(meth)acrylamide such as polymers of methyl chloride quaternary
product of dimethyl aminoethyl acrylate or a copolymer thereof with
acrylic amide. The cationic high-molecular flocculants also include
quaternary product of dialkyl aminoalkyl (meth)acrylic amide or an
acid salt thereof, and polymers or copolymers thereof with
(meth)acrylic amide, such as copolymer of methyl chloride
quaternary product of dimethyl amino propyl and acrylic amide. The
cationic high-molecular flocculants also include cationated modified
product of polyacrylamide , such as Mannich modified product and
Hoffman decomposition product of polyacrylamide, and an epihadrinamine
condensates, such as a polycondensate of epihadrin and C2 to
C6 alkylene diamine. The cationic high-molecular flocculants also
include polydimethyl diallyl ammonium chloride, polyvinyl
imidazoline and/or salts thereof, dicyan diamide condensates, such
as a formalin condensate of dicyanamide and ammonium chloride.
The cationic high-molecular flocculants also include polyethylene
imine, its quaternary product or acid salts thereof polyvinyl
imidazole, its quaternary product or acid salts thereof, poly-4- vinyl
benzyl trimethyl ammonium chloride, chitosan and its salts. The
cationic high-molecular flocculants also include acidic hydrolyzates
of N-vinyl formamide/ acrylonitrile copolymer, its quaternary
product or acid salts, polyvinyl pyridine and tis quaternary product
or acid salts. The cationic high-molecular flocculants further
include an alkylene dichloride and polyalkylene polyamine
c o n d e n s a t e s , a n i l i n e - f o r m a l d e h y d e p o l y c o n d e n s a t e s ,
polyhexameythylene thiourea acetate, polyamino acids, such as
polylysin, polyglutamic acid and its salts.
The anionic high-molecular flocculants include partial
hydrolyzates of polyacrylic amide and polymethacrylic amide,
copolymers of acrylic acid or methacrylic acid and acrylic amide or
methacrylic amide and salts thereof. The anionic high-molecular
flocculants also include acrylic acid or methacrylic acid and acrylic
amide or methacrylic amide and 2-acryl amide- methyl propane
sulfonic acid or vinyl sulfonic acid ternary copolymer and salts
thereof. The anionic high-molecular flocculants also include sodium
salts of alginic acid, Guar gum, carboxymethyl cellulose and starch,
polystyrene sulfonic acid and salts thereof. The anionic highmolecular
flocculants further include sulfonated products and salts
of polystyrene-based resin waste materials, such as polystyrene,
high-impact polystyrene, ABS resin, SAN resin, nitrile rubber. The
waste materials may contain up to 60 wt% of polyphenylene ether,
polycarbonates, polyethylene terephthalates, polyamides and
polyphenylene sulfide.
Of these high-molecular flocculants, sulfonated styrene-based
polym.ers are desirable in that these exhibit high clarifying effect for
' a liquid suspension and can be fabricated using waste materials as
the high-molecular flocculant f the present invention.
Examples of the styrene-based polymers used for the highmolecular
flocculants include styrene- butadiene, styreneacrylonitrile,
styrene- butadiene- acrylonitrile, styrene- (meth)acrylic
acid, styrene- (meth)acrylate (aliphatic hydrocarbon having 1 to 4
carbon atoms), styrene- acrylonitrile- (meth)acrylate (aliphatic
hydrocarbon having 1 to 4 carbon atoms), styrene- butadiene-
(meth)acrylate (aliphatic hydrocarbon having 1 to 4 carbon atoms),
styrene- maleic anhydride, styrene- acrylonitrile (meth)acrylate
(aliphatic hydrocarbon having 1 to 4 carbon atoms), styrenebutadiene-
acrylonitrile and styrene- maleic anhydride. Preferred are
styrene- butadiene, styrene- acrylonitrile, styrene- butadieneacrylonitrile,
styrene- maleic anhydride, styrene- acrylonitrile-
(meth)acrylic acid ester (aliphatic hydrocarbon having 1 to 4 carbon
atoms) and styrene- butadiene- (meth)acrylate (aliphatic hydrocarbon
having 1 to 4 carbon atoms). Most preferred are styrene- butadiene,
styrene- acrylonitrile, styrene- butadiene- acrylonitrile, styrenemaleic
anhydride.
The above-mentioned styrene-based polymers may be a newly
prepared material, that is a so-called virgin material, for producing
the high-molecular flocculant, waste materials from factories, retail
stores or homes (waste materials) or the combination of the virgin
material and the waste material. For re-exploitation of the
polystyrene-based resin products, manufactured in large quantities
as general-purpose resins, and for maintaining the earth's
environments, it is more desirable to use the waste materials rather
than the virgin materials, as the styrene-based polymers.
If the waste materials are used, polymers other than the abovementioned
styrene-based polymers may be contained in addition to
the styrene-based polymers. These other polymers may be
exemplified by polyphenylene ether, polycarbonates, polyphenylene
sulfides and polyethylene terephthalates. Most preferred are
polyphenylene ether and polycarbonates. The content of these other
polymers is preferably not more than approximately 60 wt%.
The above-mentioned styrene-based polymers are sulfonated in
a solvent containing sulfonating agents. The sulfonated styrenebased
polymer is converted into high-molecular flocculant by
neutralizing the sulfone groups and subsequently distilling off the
solvent and the sulfonating agent.
These sulfonating agents may be enumerated by sulfuric
anhydride, fuming sulfuric acid, chlorosulfonic acid and concentrated
sulfuric acid. These sulfonating agents may be used alone or in
combination. As for the amount of addition of the sulfonating
agents, these may preferably be used in an amount of 0.5 to 2 mols
and more preferably in an amount of 0.7 to 1.5 mol to 1 mole of
the aromatic ring contained in the styrene-based polymer (benzene
ring in a side chain for a styrene-based resin and a benzene ring in
the main chain for a polycarbonate resin). If added in an excessively
small amount, the sulfonation agent cannot sufficiently sulfonate the
styrene-based polymer. Thus, in such case, the high-molecular
flocculant cannot display its function as the high-molecular
electrolyte. Conversely, if added in an larger quantity, gelated
products are yielded during the sulfonating reaction or by-products,
such as salts, are yielded in larger quantities. Therefore, in this
case, a large quantity of impurities are contained n the highmolecular
flocculant, thus lowering its purity.
For sulfonating the strene-based polymer, the above-mentioned
sulfonating agent may be used in conjunction with the Louis acid,
which may be enumerated by alkyl phosphate, such as triethyl
phosphate or trimethyl phosphate, dioxane, acrylic anhydride, ethyl
acetate, ethyl palmitate diethyl ether and thioxane. The amount of
addition of the Louis acid is 0.01 to 2.0 mol and preferably 0.02 to
1.0 mol of the aromatic ring contained in the styrene-based polymer
(benzene ring in a side chain for a styrene-based resin and a
benzene ring in the main chain for a polycarbonate resin). If added
in an excessively small amount, gelated products tend to be yielded
during the sulfonating reaction. If conversely the Louis acid is
added in an excessive amount, the sulfonating reaction itself is
retarded to lower the yield of the high-molecular flocculant to raise
production cost.
The solvent used for sulfonating the styrene-based polymers
may be enumerated by Cl to C2 aliphatic halogenated hydrocarbons
(preferably 1,2- dichloroethane, chloroform, dichloromethane and
1,1- dichloroethane), and aliphatic cyclic hydrocarbons, preferably
cyclohexane, methyl cyclohexane and cyclopentane. These ;solvents
may be used alone or as a mixture. Im mixing the solvents,! there is
no particular limitation to the mixing ratio.
The above-mentioned solvents may be used as a mixture with
other solvents. These other solvents may be enumerated by
paraffinic hydrocarbons (with 1 to 7 carbon atoms), acetonitrile,
carbon disulfide, tetrahydrofuran, tetrahydropyrane, 1, 2- dimethoxy
ethane, acetone, methylethylketone and thiophene. Preferred of the
other solvents are Cl to C7 paraffinic hydrocarbons,
tetrahydrofuran, acetone and acetonitrile. Although there is no
particular l i m i t a t i o n to the mixing r a t io with the other solvents, the
mixing ratio is preferably in a range o 1 to 100 vol%. The abovementioned
solvents may be recovered, such as by extraction or
distillation, after the end of the sulfonating reaction of the styrene-
based polymer, for re-use in the next sulfonating reaction.
The above-mentioned anionic high-molecular flocculant can be
obtained on mixing pre-set amounts of the sulfonating polymers,
sulfonating agents and the solvent and continuing the sulfonating
reaction.
In the course of the sulfonating reaction, the concentration of
the styrene-based polymer is preferably 0.1 to 30 wt% and more
preferably 0.5 to 20 wt%. If the concentration is lower than this
range, it becomes difficult to introduce sulfone groups. If
conversely concentration is lower than this range, gelated products
tend to be yielded during the sulfonating reaction or non-reacted
substances are yielded in large quantities.
The reaction temperature for this sulfonating reaction is 0 to
100°C and preferably 15 to 80°C. If the reaction temperature is
lower than this range in the sulfonating reaction, the sulfonating
reaction is less liable to occur thus lowering the yield of the highmolecular
flocculant.
In addition, in the present sulfonating reaction, the reaction
time duration, exclusive of the sulfonating agent dripping time, is
10 minutes to 10 hours and preferably 30 minutes to 5 hours.
After the end of the sulfonating reaction of the solution, the
26-
sulfone groups are neutralized by a neutralizing agent and
subsequently the solvent is distiled off to yield the desired highmolecular
flocculant.
The neutralizing agent may be enumerated by oxides,
hydroxides, carbonates, acetates, sulfonates, phosphates of basic
compounds, such as alkali metals (sodium, lithium or potassium),
alkali earth metals (magnesium or calcium), ammonia and a variety
of amine compounds (primary to tertiary alkyl amines). This
neutralizing agent is gradually added to the reaction system in the
state of a solid or an aqueous solution to neutralize the sulfone
groups introduced into the styrene-based polymer. The techniques
for distilling off the solvent may be the techniques of liquid
separation or distillation.
With the high-molecular flocculant of the present invention,
thus obtained, its molecular weight Mw needs to be 150000 to
600000. If the molecular weight of the styrene-based polymer in the
high-molecular flocculant is less than 150000, not only is the
flocculant effect for the suspended substances in the liquid
suspension lowered, but also the suspended substances are
dispersed. Conversely, if the molecular weight of the styrene-based
polymer is not less than 600000, the suspended substances are
aggregated as coarse blocks such that optimum clarifying effects
cannot be produced while the yielded cake is of high water content.
On the other hand, with the present high-molecular flocculant,
not less than 40 mol% and preferably not less than 50 mol% of
sulfone groups are i n t r o d u c e d i n to t h e styrene-based polymer. If the
content of the sulfone groups in the styrene-based polymer is
smaller than 40 mol%, the high-molecular flocculant is lowered in
solubility in water, thus significantly lowering the flocculant effect
for the starting material in the liquid suspension.
For introducing a desired amount of sulfone groups, it is
desirable for the styrene units to be contained in the styrene-based
polymer in the high-molecular flocculant in an amount not less than
60 mol% and preferably in an amount not less than 80 mol%. If the
amount of styrene units in the styrene-based polymer is less than 60
mol%, it becomes difficult to obtain the high-molecular flocculant
having the above-mentioned amount of sulfone groups by the
sulfonating reaction.
Besides these high-molecular flocculants, flocculants of natural
origin may be used in conjunction with the high-molecular flocculant
of the present invention. The flocculants of natural origin may be
enumerated by 'moroheiya', its dried product and extracts, jelly-like
portion of the tomato seeds, its dried product or extract.
The 'moroheiya' is an annual grass of the genus Corcorus of
the class shinanoki cultivated in Arabian tropical areas such as
Egypt, Syria, Jordan or Iran, and is used from old as food as green
to yellow vegetables. The viscous acidic polysaccharides as main
component of the moroheiya are used as flocculant.
Specifically, the flower, stalk, root or portions thereof of
moroheiya are turned into paste which is used as the flocculant.
Alternatively, the flower, stalk, root or portions thereof of
moroheiya are dried and pulverized in a mixer to produce powders
which are used as the flocculant. For drying the moroheiya, drying
in the sun, air in shade, vacuum drying, hot air drying or freeze
drying may be optionally employed.
The tomato is an annual plant of the class eggplant in the
temperate zone and used from old as food as green to yellow
vegetables. It is the jelly-like portion around the tomato seed that
is used as the flocculant.
Specifically, the jelly-like portion around the tomato seed is
pulverized directly or in the dried state by a mixer to produce
powders which are used as the flocculant. For drying, the techniques
similar to those for the moroheiya are used.
Further, the paste or powders of the moroheiya or the jellyshaped
portion around the tomato seed or its dried product are
processed by extraction with water, warm water, hydrophilic organic
solvents (alcohols, ethers, N,N-dimethyl formamide or dimethyl
sulfoxide sugar, or mixtures thereof, to produce a liquid extract
which is used as the flocculant. The liquid extract may also be
fractionated or dried for use as the flocculant. The liquid extract
may preferably be water or warm water.
The liquid extract may be re-precipitated in an organic solvent
as a poor solvent or the re-precipitated product may further be
dried for use as a flocculant.
The liquid extract may be freed from solid substances by
filtration, if so desired.
The alkalis may be ammoniac water, various amine compounds,
sodium hydroxide, potassium hydroxide, potassium hydroxide and
sodium carbonate. The acids may be organic acids, such as lactic
acid, butyric acid, acetic acid or formic acid, and inorganic acids,
such as sulfuric acid, hydrochloric acid and nitric acid.
Of course, the viscous portion of moroheiya and around tomato
seeds may directly be used as the flocculant. However, it is more
effective to use the viscous portions as powders or liquid extract
for facilitating the diffusion in the processing liquid ( liquid
suspension). Also, the viscous portions of moroheiya and around
tomato seeds, processed with extraction with water, warm water or
water-soluble organic solvents, are more meritorious than the
directly dried viscous portions in flocculant effect per unit weight
of the same solid substance.
If the polysaccharide component of moroheiya or the viscous
portions around tomato seeds are pulverized or heated excessively,
these components are lowered in flocculant activity due to the
lowering of the molecular weight caused by cutting of the main and
side chains or due to insolubility in water caused by the
intramolecular cross-linking reaction.
The high-molecular flocculant of the present invention may be
used in conjunction with any of the above-mentioned flocculants.
If the high-molecular flocculant of the present invention is used in
conjunction with reverse type high-molecular flocculants, special
techniques need to be used for effective processing.
If, for example, the high-molecular flocculant of the present
invention is charged positively, as when the high-molecular
flocculant has a molecular structure portion added to with amino
compounds such that it is converted to an acid salt or a quaternary
ammonium salt, and if the high-molecular flocculant is used in
conjunction with the above-mentioned anionic high-molecular
flocculant, the two flocculants are of opposite polarities in water.
Therefore, the flocculants are preferably used sequentially rather
than as a mixture. Similarly, if the high-molecular flocculant of the
present invention is charged positively, as when cyano groups are
converted to carboxylic group via carbamoyl group, and if the highmolecular
flocculant is used in conjunction with the abovementioned
cationic high-molecular flocculant, the two flocculants
are of opposite polarities in water. Therefore, the flocculants are
again preferably used sequentially rather than as a mixture.
If the two flocculants are used sequentially, any one of the
cationic high-molecular flocculant and the anionic high-molecular
flocculant may be charged first into water for processing. However,
if the water for processing is sewage water, the cationic highmolecular
flocculant is usually charged first, since the usual sewage
water is generally processed with bactericidal treatment and hence
the colloids are charged to negative polarity.
In the water processing method of the present invention, the
high-molecular flocculant of the present invention may also be used
in conjunction with inorganic flocculants or f l o c c u l a t i o n assistant
agents.
The inorganic flocculants may be enumerated by aluminum
sulfate, aluminum polychloride, sodium aluminate, ferrous chloride,
ferric chloride, ferric sulfate, copper chloride, modified basic
aluminum sulfate (LACS) and activated silica.
The flocculation assistant agents may, for example, be
enumerated by slaked lime, sodium silicate, bentonite and flyash.
These ingredients are generally added in amounts of 0.001 to
2000 ppm and preferably 0.1 to 500 ppm, related to waste water,
depending on the concentration of the starting material or the type
of the dehydrating equipment.
Although there is no limitation to the type of the water for
processing in accordance with the present invention, maximum
effects can be produced when the water for processing is highly
contaminated water, such as plant waste water having inorganic
particles as the starting material.
The amount of addition of the high-molecular flocculant of the
present invention to water for processing differs with the
composition of the water for processing and with the combination
with other starting material and the flocculation assistant agents.
If the amount of addition is too small, the particles of the starting
material cannot be flocculated sufficiently, whereas, if the amount
is too large, the proportion of the high-molecular flocculant not
contributing to flocculation is increased to lead to wastage of the
high-molecular flocculant to give rise to renewed water
contamination. The desirable range of addition is generally 0.001 to
2000 ppm and more preferably 0.1 to 500 ppm.
For processing waste water using the high-molecular flocculant
of the present invention, coagulating agents, chelate resins,
chelating agents, activated charcoal, ozonized water, ion exchange
resins, water-absorptive resins, aqueous hydrogen peroxide,
chlorine, liquid chlroline, sodium hypochlorite, chlorine dioxide,
bleaching powder, chlorinated isocyan, diatomaceous earth, optical
catalysts, such as titanium oxide, and biological processing agents,
may be used.
Also, a variety of dehydrates, such as belt press dehydrator,
centrifugal dehydrator or a screw press may be used. Dehydrated
products, such as cakes, may be used for land filling using known
techniques or converted into fuel or composts.
EXAMPLES
The present invention is hereinafter explained with reference
to illustrative Examples based on experimental results.
[Modification of Cyano-Group Containing High-Molecular Waste
Materials by Addition of Amino Compounds]
First, the high-molecular waste material containing cyano
groups is reacted with amino compounds to produce a highmolecular
flocculant in order to check into its properties.
The following three high-molecular waste materials, containing
cyano groups, we used in the following experiments.
•Acrylic fiber waste material a
waste material of acrylic fibers for underwear containing not
less than 95 mol% of acrylonitrile
•nitrile resin waste material b
waste material of vessels for cosmetics containing not less
than 90 mol% of acrylonitrile
•SAN (styrene- acrylonitrile) resin waste material c
waste material of 8 mm cassette casing (transparent portions)
containing 40 mol% of acrylonitrile
The above three waste materials were processed into smallsized
chips for use as starting material. The acrylic fiber waste
material was severed by scissors into small-sized chips with each
side 5 mm or less in length, while the nitrile resin waste material
b and the SAN resin waste material c were severed by a cutter type
crusher into small-sized chips not larger than 16 mesh for use as
starting material.
Example 1
4 g of 1, 3- propane diamine, 0.03 g of sulfur powders and 1.0
g of small pieces of acrylic fiber waste material a were charged into
40 g of cyclohexane and stirred in situ to carry out an addition
reaction at 60°C for four hours.
A green solid substance, precipitated on the bottom of the
reaction vessel, was taken out and dissolved. The resulting solution
was poured into a large quantity of acetone and precipitated.
The precipitate was then filtered and dried in vacuo at room
temperature to yield pale y e l l ow powders.
The resulting powders were analyzed by Fourier transform IR
absorption spectrum (FT-IR) and nuclear magnetic resonance (NMR)
spectrum. Jt was found that 80 mol% of cyano groups in the solid
reaction product had been converted to imidazoline rings and that
these imidazoline rings were not hydrolysed. The resulting powders
were also soluble in water.
These powders were termed a high-molecular flocoulant A.
This high-molecular flocculant A was of the nonionic type.
Example 2
An imidazoline ring containing polymer was obtained in the
same way as in Example 1 except using 3.5 g of ethylene diamine
as an amino compound.
This polymer was dissolved in water and methyl chloride was
injected into the resulting mass. The resulting product was reacted
at 40°C for two hours to yield an aqueous solution of a methyl
chloride quaternary salt polymer of imidazoline, while nonl-reacted
methyl chloride was distilled off on heating.
The resulting product was termed a high-molecular flocculant
B. This high-molecular flocculant B was of the cationic type.
Example 3
1.0 g of small pieces of nitrite resin waste material b was
dissolved in 100 ml of dimethyl sulfoxide (DMSO). To the resulting
mass were dripped 2.3 g of ethanolamine at room temperature. The
resulting mass was stirred in situ and heated to 100°C to carry
out the reaction for 12 hours.
After the end of the reaction, the reaction solution was poured
into ethanol and precipitated. After filtration, the resulting product
was rinsed with methanol and dried in vacuo at room temperature.
The above processing yielded a polymer in which 85% of the cyano
groups were replaced by an imino structure.
The resulting product was termed a high-molecular flocculant
C. This high-molecular flocculant C was of the cationic type.
Example 4
An imino group containing polymer was obtained in the same
way as in Example 3 except using 2.8 g of butylamine as an amino
compound.
This polymer was dissolved in water and admixed with an
aqueous solution of dilute sulfuric acid to set pH to 4.0 to obtain
a sulfate polymer solution.
The resulting product was termed a high-molecular flocculant
D. This high-molecular flocculant D was of the cationic type.
Example 5
A high-molecular flocculant was produced in the same way as
n Example 2 except using SAN resin waste material c as a starting
material.
This high-molecular flocculant was termed a high-molecular
flocculant E which was of the cationic type.
Example 6
The high-molecular flocculant C was dissolved in water and the
r e s u l t i n g aqueous solution was heated at 90°C for 15 hours. After
the end of the heating, the aqueous s o l u t i o n was dried to produce
powders, for which the Fourier transform IR absorption spectrum
(FT-IR) and nuclear magnetic resonance (NMR) spectrum were
measured. By these measurements, it was confirmed that 70 mol%
of the imino structure was hydrolysed and converted to an amide
structure.
This high-molecular flocculant was termed a high-molecular
flocculant F which was of the nonionic type.
Example 7
0.05 g of sulfur powdered and 1.0 g of small pieces of waste
acrylic fiber material a were added to 20 g of ethylene diamine and
reaction was carried out at 110°C for six hours. After the end of
the reaction, non-reacted ethylene diamine was distiled off by
distillation in vacuo and the residual mass was dissolved in water
and precipitated with acetone.
The precipitates were then filtered and dried in vacuo at room
temperature to produce brown powders. For these powders, the
Fourier transform IR absorption spectrum (FT-IR) and nuclear
magnetic resonance (NMR) spectrum were measured. By these
measurements, it was confirmed that 42 mol% of the cyano groups
of the solid reaction product were converted to imidazoline rings,
and 18 mol% thereof were converted to - amino ethyl acrylamide
which was a hydrolizate.
This polymer was then dissolved in water and a dilute aqueous
solution of hydrochloric acid was added to the s o l u t i o n to give an
aqueous solution of a hydrochlorate polymer.
This high-molecular flocculant was termed a high-molecular
flocculant G which was of the nonionic type.
[Evaluation of Flocculant Performance]
The flocculant performance of these high-molecular flocculants
A to G were evaluated.
In the following set of test examples, the following flocculants
were used with a view to comparison or use with the inventive
products.
•Nonionic high-molecular flocculant H: commercial polyacrylamide
•cationic high-molecular flocculant I: methyl chloride quaternary
product of commercial polydimethyl amino ethyl acrylate (potent
cationic type)
•anionic high-molecular flocculant J: commercial polyacryl amide
partial hydrolyzate (mid anionic type)
•sulfonate of waste resin material K: sodium polystyrene sulfonate
( starting material: expanded styrene, sulfonation ratio: 80 mol%)
•hydrolyzate L of waste fiber: polyacrylonitrile hydrolyzate (acrylic
fibers processed with sodium hydroxide)
•flocculant M of natural origin: dried pulverized moroheiya leaves
Evaluation test 1
A 1 wt% aqueous solution of kaoline was prepared and used
as a liquid suspension for evaluation of flocculation (this solution
is hereinafter termed a liquid suspension). 100 ml of this liquid
suspension were charged into a measuring cylinder with a co-plug
having a capacity of 200 ml. The high-molecular flocculant and
conventional high-molecular flocculants for comparison were dripped
into the liquid suspension using measuring pipettes. The dripping
amounts were set so that the concentration of the high-molecular
flocculant in the liquid suspension was equal to 4 ppm.
After dripping, the measuring cylinder was stopped with the
plug and turned upside down and restored repeatedly ten times. The
measuring cylinder was then restored to the stationary state to
measure the rate of precipitation of the suspended particles and the
turbidity of the supernatant liquid. The measured results are shown
in Table 1.
(Table Removed)
It is seen from table 1 that nonionic high-molecular
flocculants, modified by addition of the amino compound to the
cyano group, showed more satisfactory results in the rate of
precipitation and in turbidity of the supernatant liquid than the
conventional nonionic flocculant and exhibited superior flocculating
performance.
Evaluation Test 2
The processed liquid, obtained on primary flocculiation of
waste water from an electronic parts plant (pH 6.5, SS 1.5 wt%)
was used as a liquid suspension for evaluation of flocculation.
100 ml of the liquid suspension were charged into a measuring
cylinder with a co-plug, having a capacity of 200 ml and each
flocculant was dripped into the liquid suspension using a measuring
pipette. The dripping amount was set so that the high-molecular
flocculant in the liquid suspension will be of the concentration
equal to 2 ppm. If two sorts of the liquid suspension were used
together, these flocculants were mixed together so that the above
concentration will be equal to 1 ppm.
After dripping, the measuring cylinder was stopped with the
plug and turned upside1 down and restored repeatedly ten times. The
measuring cylinder was then restored to the stationary state to
measure the rate of precipitation of the suspended particles,
turbidity of the supernatant liquid and the water content of the cake
obtained after filtration by a filter cloth.. The measured results are
shown in Table 2.
(Table Removed)
It is seen from table 2 that the high-molecular flocculant of
the present invention was superior to the conventional anionic
flocculant in the rate of precipitation, turbidity of the supernatant
liquid and in water content of the cake. It has also been seen that
the high-molecular flocculant of the present invention can further
be improved in flocculation performance by using it as a mixture
with commercial anionic flocculants.
Evaluation Test 3
A mixed sludge from a sewage processing plant (pH, 6.2; SS
2.5 wt%) was pit to a j a r test.
First, 0.5 wt% per SS of a cationic high-molecular flocculant
was added to the sludge being agitated by a jar tester and agitated
for flocculation. If two sorts of the high-molecular flocculant were
used as a mixture, the charged amounts of the flocculants were set
to 0.2 wt% per SS. To the resulting product was further added 0.2
wt% of the anionic high-molecular flocculant per SS and agitated
for flocculation.
The flocculated mass was then allowed to stand and
measurement was then made of the rate of precipitation of
suspended particles, turbidity of the supernatant liquid and the
water content of the cake obtained on filtration. The measured
results are shown in table 3.
(Table Removed)
It is seen from table 3 that the high-molecular flocculant of
the present invention was superior to the conventional anionic
flocculant in the rate of p r e c i p i t a t i o n , t u r b i d i t y of t h e supernatant
liquid and in water content of the cake both when used alone and
when used in conjunction with the anionic flocculant. It has also
been seen that the high-molecular flocculant of the present invention
can further be improved in flocculation performance by using it as
a mixture with flocculants of natural origin.
[Modification of Waste High-molecular Material by Hydrolysis of
Cyano Groups]
The following four high-molecular materials were used as base
materials for hydrolysis in the respective Examples,
•waste acrylic fibers d
waste acrylic fibers for underwear containing not less than 90
mol% of acrylonitrile;
•waste nitrile rubber e
waste oil-resistant rubber and hose material containing not less
than 40 mol% of acrylonitrile;
•waste nitrile resin/
waste vessels for cosmetics containing not less than 90 mol%
of acrylonitrile;
•SAN (styrene-acrylonitrile) waste resin g
waste battery casing material containing not less than 30
mol% of acrylonitrile;
The waste material d was severed with scissors into small
pieces each having a side measuring 5 mm or less.
The waste material e was freeze-pulverized to small pieces
each measuring 32 mesh or less.
The waste materials / and g were pulverised to small pieces
measuring 32 mesh or less using a cutter type pulveriser.
Example 8
0.6g of the waste material d was charged into 30 g of 96%-
sulfuric acid and agitated in situ to carry out acidic hydrolysis at
50°C for two hours. The waste material d was completely dissolved
in sulfuric acid.
Next, this mixture was poured in a large quantity of acetone
to yield a white precipitate, which was further washed twice or
thrice with acetone and dried.
The dried powders were analyzed by measurement with the
Fourier transform IR absorption spectrum (FT-IR) and nuclear
magnetic resonance (NMR) spectrum. By these measurements, it
was confirmed that not less than 90 mol% of the cyano groups in
the waste material d were converted to carbamoyl groups and that
no carboxylic groups were generated under the above-mentioned
reaction conditions. These powders were also readily soluble in
water.
These powders were termed a high-molecular flocculant N.
The ion type of this high-molecular flocculant N was the nonionic
type.
Example 9
The acid hydrolysis was carried out by the same method as in
Example 8 except using the waste material e and setting the
reaction temperature and reaction time to 80°C and 4 hours,
respectively.
The FT-IR and NMR measurements, conducted on the resulting
powders, revealed that not less than 90 mol% of the cyano groups
in the waste material e were converted to carbamoyl groups and that
no carboxylic groups were generated under the above-mentioned
reaction conditions. These powders were also readily soluble in
water.
These powders were termed a high-molecular flocculant O.
The ion type of this high-molecular flocculant 0 was the nonionic
type.
Example 10
The acid hydrolysis was carried out by the same method as in
Example 8 except using the waste material/and setting the reaction
temperature and reaction time to 80°C and 4 hours, respectively.
The FT-IR and NMR measurements, conducted on the resulting
powders, revealed that not less than 90 mol% of the cyan0 groups
in the waste material / were converted to carbamoyl groups and that
no carboxylic groups were generated under the above-mentioned
reaction conditions. These powders were also readily soluble in
water.
These powders were termed a high-molecular flocculant P.
The ion type of this high-molecular flocculant P was the nonionic
type.
Example 11
The acid hydrolysis was carried out by the same method as in
Example 8 except using the waste material g and setting the
reaction temperature and reaction time to 80°C and 4 hours,
respectively.
The FT-IR and NMR measurements, conducted on the resulting
powders, revealed that not less than 90 mol% of the cyano groups
in the waste material g were converted to carbamoyl groups and that
no carboxylic groups were generated under the above-mentioned
reaction conditions. These powders were also readily soluble in
water.
These powders were termed a high-molecular flocculant Q.
The ion type of this high-molecular flocculant Q was the nonionic
type.
Example 12
1 g of the waste material d was charged into 40 g of
cyclohexane and, as the temperature of the reaction system was
controlled to 25 to 30°C, 1.8 g of sulfuric anhydride was dripped
over 30 minutes. After the end of dripping, agitation was continued
for further 30 minutes. 30 g of water were added to the reaction
system to carry out hydrolysis at 30° for one hour.
The reaction mixture was distilled in vacuo to remove
cyclohexane and the residual liquid was adjusted to pH of 6 to
produce a high-molecular aqueous solution. The FT-IR and NMR
measurements, conducted on the resulting high-molecular aqueous
solution, revealed that not less than 90 mol% of the cyano groups
in the waste material d were converted to carbamoyl groups and that
no carboxylic groups were generated under the above-mentioned
reaction conditions. These powders were also readily soluble in
water.
These powders were termed a high-molecular flocculant R.
The ion type of this high-molecular flocculant R was the nonionic
type.
Example 13
To a 1%-aqueous solution of the high-molecular flocculant N,
obtained in Example 8, sodium hydroxide (NaOH) equivalent to 50
mol% of carbamoyl groups of the high-molecular flocculant N was
added to carry out alkaline hydrolysis at 80°C for one hour.
The FT-IR and NMR measurements, conducted on the resulting
high-molecular aqueous solution, revealed that, of the carbamoyl
groups of the high-molecular flocculant N, 90 mol% of the added
amount of NaOH, corresponding to 45 mol% of the initial carbamoyl
group content, were converted to sodium salt type cdrboxylic
groups.
These powders were termed a high-molecular flocculant S.
The ion type of this high-molecular flocculant S was the anionic
type.
Example 14
To a 1%-aqueous solution of the high-molecular flocculant R,
obtained in Example 12, sodium hydroxide (NaOH) in an equimolar
amount to carbamoyl groups of the high-molecular flocculant R was
added to carry out a l k a l i n e hydrolysis at 80°C for one hour.
The FT-IR and NMR measurements, conducted on the resulting
high-molecular aqueous solution, revealed that, of the carbamoyl
groups of the high-molecular flocculant R, 90 mol% of the added
amount of NaOH, corresponding to 90 mol% of the initial carbamoyl
group content, were converted to sodium salt type carboxylic
groups.
These powders were termed a high-molecular flocculant T.
The ion type of this high-molecular flocculant T was the anionic
type.
The high-molecular flocculants obtained in Examples 8 to 14
are indicated collectively in Table 4.
(Table Removed)
In Table 4, the content of the as-modified functional groups
refers to the total number of mols of the monomeric units making
up the high-molecular material.
[Evaluation of Flocculating Performance]
Next, the flocculating performance of the high-molecular
flocculants N to T was evaluated.
In the following set of the evaluation tests, the following two
commercial high-molecular flocculants U, V were used with a view
to comparison and conjunctive use with the inventive products.
•High molecular Flocculant U
partial hydrolyzate of polyacrylamide portion (hydrolyzation
rate, 20 mol%), anionic type
•High molecular Flocculant V
Methyl chloride quaternary product of dimethyl amino ethyl
acrylate, potent cationic type
Evaluation Test 4
0.2 wt% of aluminum sulfate as added to a 4 wt%-aqueous
solution of kaoline to give a colloidal liquid suspension for
flocculation evaluation (referred to hereinafter as liquid
suspension).
100 ml of this liquid suspension were charged into a measuring
cylinder with a co-plug having a capacity of 200 ml. The highmolecular
flocculants N to T and conventional high-molecular
flocculants for comparison were dripped into the liquid suspension
using measuring pipettes. The dripping amounts were set so that the
concentration of the high-molecular flocculant in the liquid
suspension was equal to 5 ppm.
After dripping, the measuring cylinder was stopped with the
plug and t u r n e d upside down and restored repeatedly ten times. The
measuring cylinder was then restored to the to the stationary state
to measure the rate of precipitation of the suspended particles and
the turbidity of the supernatant liquid.
The measured results are shown in Table 5.
(Table Removed)
On comparison of the flocculating performance of tjie highmolecular
flocculants N to T of the present invention according to
ion types, the anionic type high-molecular flocculants S and T are
superior to the nonionic type high-molecular flocculants N to R.
Therefore, in flocculating the colloidal system in which kaoline is
flocculated primarily with aluminum sulfate used in the present
Example, the anionic type high-molecular flocculants S and T may
be said to be superior to the hydrogen bonded type nonionic highmolecular
flocculants N to R.
Thus, on comparing the flocculating performance of the same
anionic type flocculants, the anionic type high-molecular flpcculants
S and T of the present invention are superior to the conventional
anionic type high-molecular flocculant. Moreover, the conventional
product U was inferior in performance the nonionic type highmolecular
flocculants N to R of the present invention.
This indicated the superior flocculating performance of the
inventive products.
Evaluation Test 5
500 ppm of aluminum sulfate were added to the waste water
of an electronic parts plant (pH, 4.8; mass of the floating substance
(SS) of 1.2 wt%) to prepare a liquid suspension for flocculation
evaluation (referred to hereinafter as liquid suspension).
100 ml of this liquid suspension were charged into a
measuring cylinder with a co-plug having a capacity of 200 ml. An
aqueous solution of the high-molecular flocculant was dripped into
the liquid suspension using measuring pipettes. The high-molecular
flocculants used here were the nonionic high-molecular flocculants
N, 0, anionic high-molecular flocculants S, T and the conventional
anionic high-molecular flocculant U.
The inventive products N, 0 and S were used as an 50-50
mixture with the conventional product U, whilst the inventive
product T and the conventional product U were used alone. The
high-molecular flocculants were added in amounts which would give
concentration of 10 ppm in the liquid suspension. Thus, if the two
flocculants were used in conjunction, the inventive product and the
conventional product are used each in the concentration of 5 ppm.
After dripping, the measuring cylinder was stopped with the
plug and turned upside down and restored repeatedly ten times. The
measuring cylinder was then restored to the stationary state to
measure the rate of precipitation of the suspended particles and the
turbidity of the supernatant liquid. The precipitate yielded was
dehydrated on a filter cloth to measure the water content in the
cake.
The measured results are shown in table 6.
(Table Removed)
On comparing the case of using the high-molecular flocculant
T of the present invention to that of using the conventional highmolecular
flocculant U, as cases of using the sole high-molecular
flocculant, the inventive product is superior in flocculating
performance. It is noted that these two flocculants are both of the
anionic type. The conventional product, inferior by itself to the
inventive product, is improved in flocculating performance on
combination with the inventive products N, 0 and S. This verified
superior flocculating performance proper to the inventiv e product.
However, in any of the above cases of combined use, the
flocculating performance of the present invention in which anionic
high-molecular flocculants T was used by itself could not be
surpassed as far as turbidity was concerned. This is probably
ascribable to the fact that the inventive product is smaller in
molecular weight and higher in anionic efficiency than the
conventional product.
Similar effects could be obtained when the commercial highmolecular
flocculant used on mixing with the inventive product was
changed to the nonionic type.
Evaluation Test 6
A jar test was conducted on a mixed sludge from a sewage
processing plant (pH, 6.6; SS, 2.8 wt%). Specifically, as tb^e above
mixed sludge was agitated by the jar tester, the commercial highmolecular
flocculant V was added in a first step to the agitated
sludge at a rate of 0.6 wt%. Then, at a second step, the highmolecular
flocculants P, Q or T or the conventional anionic highmolecular
flocculant U was added each at a rate of 0.15 wt% to the
suspended particles.
After agitation, the liquid suspension was allowed to stand
stationarily and measurements were made of the rate of precipitation
of the suspended particles and turbidity of the supernatant liquid.
Also, the produced precipitates were dehydrated on a f i l t e r uloth to
measure the water content of the cake.
The measured results are shown in Table 7.
(Table Removed)
* © and ® denote first and second stages, respectively.
In general, if the composition of the suspended particles is
complex or cannot be known correctly, static charges of the
colloidal particles is also thought to be nonuniform. It is therefore
thought to be effective to use the high-molecular flocculant of the
cationic type and that of the nonionic type simultaneously. On
comparison of the combination of the conventional cationic type
flocculant and the conventional cationic type flocculant to the
combination of the cationic and anionic type inventive products,, it
has been found that the combination of the inventive products
manifested superior flocculant effects.
In p a r t i c u l a r , the o p t i m um f l o c c u l a t i n g effects can be o b t a i n e d
on combining the conventional high-molecular flocculant and the
inventive high-molecular flocculant.
Although cationic high-molecular flocculant cannot as a
principle be manufactured on hydrolysis of cyano groups, waste
water processing can be achieved more effectively by using the
inventive flocculant in combination with the cationic commercial
flocculant.
Although the preferred embodiments of the present invention
and the results of evaluating tests have been explained in the
foregoing, it should be noted that these embodiments have been
given for i l l u s t r a t i on purposes and are not intended for limiting the
scope of the invention. Specifically, the present invention can be
optionally modified as to the types of the starting materials for the
high-molecular flocculant or conditions fro addition reaction,
hydrolytic reaction, acid salt formation or water processing.

We Claim:
1. A method for water processing comprising:
charging into water for processing a high-molecular flocculant having a molecular structure portion comprised of an inorganic and/or organic amine compound added to at least a portion of cyano groups contained in a high-molecular material.
2. The method for water processing as claimed in claim 1 wherein said high-molecular flocculant is used in conjunction with at least one of a nonionic high-molecular flocculant, an anionic high molecular flocculant and a cationic high-molecular flocculant.
3. The method for water processing as claimed in claim 2 comprising:
sequentially charging said high-molecular flocculant and theanionic high-molecular flocculant into the water for processing.
4. A method for processing water as claimed in any of claim 1 comprising a high-molecular
material at least a portion groups of which has been converted into carbamoyl groups.
5. The method for water processing as claimed in claim 4, wherein said high-molecular
flocculant is used in conjunction with at least one of a nonionic high-molecular flocculant, an
anionic highmolecular flocculant and a cationic high-molecular flocculant.
6. The method for water processing as claimed in claim 5 comprising:
sequentially charging said high-molecular flocculant and the anionic high-molecular flocculant into the water for processing.
7. The method for water processing as claimed in claim 6 comprising:
charging into the water for processing the flocculant a further portion of carbamoyl groups of which have been converted into carboxylic groups or salts thereof.
8. A method for water processing substantially as hereinbefore described with reference to the
accompanying drawings.