JPH0583282B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention has excellent storage stability in the form of a one-pack, and also has excellent agglomerating effects on water polluting components such as turbidity removal effect, decolorization effect, and phosphorus ion scavenging effect as a flocculant. The present invention relates to an inorganic and organic liquid flocculant composition. (Prior art) Conventionally, a composite inorganic flocculant containing ferric sulfate and aluminum sulfate at a certain composition ratio has the advantage of rapidly achieving a flocculating and settling effect on water polluting components in water. (For example, Japanese Patent Publication No. 39-19422). In addition, recently, Japanese Patent Publication No. 60-2885 describes a liquid inorganic flocculant composition that has an excellent combination of storage stability and flocculating effect on water polluting components.
A liquid in which the three-component composition ratio of SO ₃ , Fe ₂ O ₃ and Al ₂ O ₃ is within a certain range, and the total weight % concentration of Fe ₂ O ₃ and Al ₂ O ₃ is in the range of 4 to 15%. Inorganic flocculant compositions have been proposed and it has also been described that the liquid inorganic flocculants can be used in combination with nonionic, anionic, cationic or amphoteric polymeric flocculants. (Problems to be Solved by the Invention) Liquid inorganic flocculants and cationic polymer flocculants (hereinafter simply referred to as cationic flocculants) are used in various types of water,
When used for coagulation treatment of wastewater or sludge, etc., it is true that excellent coagulation and sedimentation effects of water pollution components can be obtained, but
If these two components are combined into a convenient one-pack liquid flocculant, the cationic flocculant will be altered due to the interaction of the amphoteric components, and the advantages of using the cationic flocculant will be lost. There is a problem that the storage stability of the agent is impaired. This tendency is remarkable in _SO3 - _Fe2O3 - _{Al2O3 -} based liquid inorganic flocculants, but it is also observed in polyaluminum chloride-based liquid inorganic flocculants whose liquid pH is _low . Therefore, the object of the present invention is to provide a liquid flocculant in which a cationic flocculant is pre-blended in a liquid inorganic flocculant, so that the combined effect of the inorganic flocculant and cationic flocculant is the same as that at the initial stage of blending. The objective is to provide a one-package type liquid flocculant that is maintained in a similar manner. Another object of the present invention is to provide an inorganic-organic cationic composite liquid flocculant having excellent storage stability and flocculating effect on water polluting components. (Means for Solving the Problems) Among various cationic flocculants, the present inventors selected a polyamine flocculant consisting of a condensation polymer of dimethylamine and epichlorohydrin, and When mixed with an aluminum-based or aluminum-iron-based liquid inorganic flocculant, a one-package type liquid flocculant with excellent storage stability can be obtained, and this composite liquid flocculant has the effects of the inorganic flocculant and the cationic flocculant. was found to be stable and sustained over a long period of time. That is, according to the present invention, aluminum-based or aluminum
Adding Al to the iron-based liquid inorganic flocculant is a polyamine flocculant that is mainly composed of a condensation polymer of dimethylamine and epichlorohydrin and has at least one nitrogen atom in the main chain and at least one hydroxyl group in the side chain per repeating unit. Al ₂ O ₃ or Al ₂ O ₃ −Fe 2 as solid content based on the total weight of ₂ O ₃ weight or Al ₂ O ₃ − Fe _{2 O 3}
The weight ratio of O ₃ /polyamine flocculant is 40/60 to
There is provided a liquid flocculant composition characterized in that it is blended in an amount satisfying the range of 98/2. In the most preferred embodiment of the present invention, the aluminum-iron based liquid inorganic flocculant is represented by a three-component composition, and SO ₃ , Fe ₂ O ₃ and Al ₂ O ₃ are combined in the following formula (i) where C is 12 or less. When S≧0.25F+72.0 S≦100-4/3C (when A is less than 2.5) F≧4/3C-2.5 (when A is between 2.5 and 4.1+3/5C) S≦98.4-29/15C ( (When A is greater than 4.1+3/5C) A≧0.5 F≧2 (ii) When C is greater than 12 S≧−0.25F+75.5 S≦84 (When A is less than 2.5) F≧13.5 (A is 2.5 to 11.3) S≦75.2 (when A is greater than 11.3) A≧0.5 F≧2 [In the formula, S, F and A are SO ₃ , Fe ₂ O ₃ per total amount of the above three components and ₃ mol% of Al ₂ O, respectively;
C represents the total weight percent concentration of Fe ₂ O ₃ and Al ₂ O ₃ in the solution. A liquid inorganic flocculant containing a satisfactory amount of Fe ₂ O ₃ and Al _{2 O 3 and having a total weight % concentration C of Fe 2 O 3 and Al 2} O ₃ in the range of 4 to 15% is used. In another preferred embodiment of the present invention, a polyaluminum chloride flocculant having an Al ₂ O ₃ weight concentration in the range of 5 to 15% by weight is used as the aluminum-based liquid inorganic flocculant. (Function) Aluminum-based or aluminum-iron-based liquid inorganic flocculants have the advantage of collecting various water polluting components contained in the material to be treated and forming flocs. The disadvantage is that the grain size of the flocs is generally small and the strength of the flocs is generally low. On the other hand, when a cationic flocculant is used in combination, a large and dense floc is formed due to its electrical charge, and this floc has the advantage of being easy to separate water and having relatively high strength to withstand shearing and the like. However, these inorganic flocculants and ordinary cationic flocculants are generally not compatible, and in order to maintain a stable liquid, it is necessary to use inorganic flocculants such as Al ₂ O ₃ or Al ₂ O ₃ −Fe ₂ O ₃ . However, it is only possible to add 5% by weight or less of a cationic flocculant, and if the cationic flocculant exceeds 15% by weight, which is required for actual combination use, the liquid itself will coagulate or precipitate. It is inevitable that it will occur. Furthermore, as shown in the examples below, when a normal cationic flocculant is blended with an inorganic flocculant, there is a tendency for the above-mentioned effects peculiar to the cationic flocculant to be lost over time. This seems to be due to an unfavorable reaction occurring between the cationic flocculant and the inorganic flocculant. This can be supported by the fact that it is recommended to use water that does not contain ions when dissolving cationic flocculants. However, the polyamine-based flocculant used in the present invention is mainly composed of dimethylamine and epichlorohydrin condensation polymer, and has at least one polyamine in the main chain per repeating unit.
It has both nitrogen atoms and at least one hydroxyl group in the side chain, and is characterized by a chemical composition that is cationic and nonionic in nature.
In the liquid flocculant of the present invention, the reason why the polyamine flocculant can exist stably in liquid form at high concentration is that the stability in the liquid is enhanced by the presence of such hydroxyl groups and the presence of hydroxyl groups. It is recognized that this is related to the effect of suppressing undesirable reactions between the cationic flocculant and the inorganic flocculant. (Description of preferred embodiments of the invention) Polyamine flocculant The polyamine flocculant used in the present invention is mainly a condensation polymer of dimethylamine and epichlorohydrin. The condensation polymer has at least one nitrogen atom in the main chain and at least one nitrogen atom in the side chain per repeating unit.
It has hydroxyl groups. In the present invention, the following general formula is used within a range that does not impede the action of this condensation polymer.

embedded image In the formula, R is a divalent hydrocarbon group, m is zero or 1, and n is a number of 150 or more. This polyamine is easily obtained by reacting ammonia or diamine with epihalohydrin. Examples of the divalent group R include alkylene groups having 2 to 6 carbon atoms such as ethylene group, tetramethylene group, and hexamethylene group, cycloalkylene groups such as cyclohexylene group, and arylene groups such as phenylene group and xylylene group. be able to. The molecular weight (number average molecular weight) of the polyamine flocculant used is preferably in the range of 20,000 to 900,000, and these are generally blended into the liquid inorganic flocculant in the form of an aqueous solution. Inorganic Liquid Flocculant Any aluminum or aluminum-iron based liquid inorganic flocculant may be used. Among these liquid inorganic flocculants, those with excellent storage stability and flocculating effect on flocculating components of water pollution components are known to have a three-component composition ratio of SO ₃ (S), Fe ₂ O ₃ (F), and Al ₂ O. ₃ (A) is regulated by the above formulas, and Fe ₂ O ₃
and a liquid inorganic flocculant having a total weight % concentration C of Al ₂ O ₃ in the range from 4 to 15%. This liquid inorganic flocculant has the above-mentioned molar composition of ferric sulfate and aluminum sulfate and Fe ₂ O ₃ and
The total weight % of Al ₂ O ₃ (R ₂ R ₃ concentration) can be easily adjusted by dissolving in water and stirring them. Of course, at this time, if necessary, the SO ₃ molar ratio can be adjusted within a predetermined range by removing the sulfate radical in the form of gypsum using a calcium-based neutralizer or by adding free sulfuric acid. Of course. In addition, a sulfate solution containing iron and aluminum obtained by extracting various clays such as acid clay and bauxite with sulfuric acid is used as a liquid flocculant by adjusting the molar ratio of various components and concentrating it. You can also get The details of this liquid inorganic flocculant can be found in
Please refer to Publication No.-2885. Other suitable examples of this liquid inorganic flocculant include:
Mention may be made of polyaluminum chloride (basic aluminum chloride) flocculants whose Al ₂ O ₃ weight concentration is in the range from 5 to 15% by weight. This basic aluminum chloride _flocculant generally has the _{formula Al 2} ( _OH ) is a number that satisfies the number of . It has the composition represented by. The method for producing the basic aluminum chloride flocculant is preferably, but not limited to, a process in which a soluble aluminum salt is reacted in an aqueous medium containing an alkali carbonate.
Neutralize to pH 6.5 to 9.8 and CO ₂ /Al ₂ O ₃
It can be produced by producing an amorphous carbonate group-containing aluminum hydroxide with a molar ratio of 0.1 or more, and dissolving this amorphous carbonate group-containing aluminum hydroxide in hydrochloric acid or a mixed acid of hydrochloric acid and sulfuric acid. . Details of this production method and the performance of the flocculant are described in Japanese Patent Publication No. 8973/1983, so please refer to it. Composite _{liquid flocculant} In _the present _{invention , polyamine} Al ₂ O ₃ or Al ₂ O ₃ −Fe ₂ with solid content of flocculant
The weight ratio of O ₃ /polyamine flocculant is 40/60 to
It is important to mix in an amount that satisfies the 98/2 range. Preferably, this weight ratio is 95/5 of 50/50.
be used so as to satisfy the range of If the amount of polyamine flocculant is lower than the above range,
By using a cationic flocculant in combination, the advantages of increasing the floc diameter and making the floc denser tend to be lost, and even if the above range is exceeded, the performance is lower than that within the range of the present invention. There is no particular advantage, and it is economically disadvantageous because it is expensive, and it also has the disadvantage that the viscosity of the liquid increases. When blending a polyamine flocculant with a liquid inorganic flocculant, there are no particular problems to be noted, and it is sufficient to adopt mixing and stirring conditions under which both are homogeneous. The composite liquid flocculant according to the present invention can be supplied to consumers in the form of a liquid that is easy to handle by so-called tank trucks, tank cars, etc., and does not form any precipitates or flocs even when subjected to vibrations and shocks during transportation. It does not form precipitates or flocs even when left for long periods of time under conditions of rapid temperature changes, maintains excellent fluidity, and has outstanding workability. In addition, the composite liquid flocculant of the present invention can be used for various types of water,
It has a remarkable advantage that it can be added to wastewater or sludge all at once as a one-package flocculant and used freely for flocculation and sedimentation of water polluting components, which greatly simplifies treatment operations. The amount of the composite liquid flocculant of the present invention to be used varies considerably depending on the content of water polluting components in the water to be treated (raw water), but the _amount of _R2O3 ( _Al2O3 weight or _{Al2O3 weight )} −
10 to 10 for water use (total weight of Fe ₂ O ₃ )
It can vary from 200ppm to 0.01 to 0.5% for sludge. When this composite flocculant is used, surprisingly, the performance of the polyamine flocculant is virtually preserved even during long-term storage in an inorganic flocculant; As a result, it becomes possible to form agglomerated flocs that are extremely easy to separate from treated water. In the treatment of wastewater and sludge, it is significantly superior in fixation and removal of phosphorus, color, turbidity, COD, etc. compared to conventional liquid flocculants, and in the treatment of river water, It is easy to remove not only phosphorus ions but also anionic surfactants. (Effects of the Invention) According to the present invention, a polyamine based on a condensation polymer of dimethylamine and epichlorohydrin and having at least one nitrogen atom in the main chain and at least one hydroxyl group in the side chain per repeating unit. By blending a flocculant with an aluminum-based or aluminum-iron-based inorganic flocculant, it has become possible to provide a composite organic-inorganic liquid flocculant in one package. This liquid flocculant not only has excellent storage stability, but also has a combined flocculation effect that is maintained stably over a long period of time. (Example) The present invention will be explained with the following example. Example 1 and Comparative Example 1 A one-package composite liquid flocculant was prepared by mixing a liquid inorganic flocculant and a liquid cationic flocculant, and its storage stability was investigated. First, as a liquid inorganic flocculant (hereinafter referred to as LA),
LA of iron-containing aluminum sulfate prepared by the method described in Japanese Patent Publication No. 60-2885 (sample numbers FA-1 and FA-2), basic iron-containing sulfuric acid prepared by the method described in JP-A-60-14911 aluminum
LA (sample number BFA-1), LA of basic aluminum chloride prepared by the method described in Japanese Patent Publication No. 60-8973 (sample number BP-1), LA of aluminum sulfate with an Al ₂ O ₃ concentration of 8.0% ( Sample number A-1) and Al ₂
LA of polyaluminum chloride (sample number P-1) with an O ₃ concentration of 10% was prepared. The properties of these liquid inorganic flocculants are shown in Table 1.

[Table] For each of the above liquid inorganic flocculants (LA), it is a polyamine-based high-condensation polymer of dimethylamine and epichlorohydrin, with a specific gravity of 1.16, PH of 3.5, viscosity of 4520 cps (at 25°C), and solid content of 50% by weight. Molecular coagulant polyamine #907 (sample number PA-1) was mixed with the R ₂ O ₃ amount of each LA at the mixing ratio (weight ratio) shown in Table 2 as a solid content, and the resulting liquid compositions were as follows: 300ml
The sample was placed in a semi-transparent sealable cylindrical container made of synthetic resin (inner volume: approximately 500 ml) and left at room temperature for 6 months, during which time the presence or absence of precipitates was visually observed every month to examine storage stability. Evaluation of storage stability was carried out in the following three stages. ○ If no precipitates are formed for 6 months, it is storage stable. △ If precipitates are formed after 3 months, storage stability is somewhat poor. × If a precipitate is formed within 1 month, the storage stability is not good at all. In addition, for the liquid compositions marked with ○, the viscosity (cps) was measured at the same time. The results are shown in Table 2. In addition, as a comparative example, cationic LB manufactured by Company A was used to
4. The storage stability of polyethyleneimine (sample number PE-1) with a viscosity of 2800 cps and a solid content of 50% was examined in the same manner. The results are shown in Table 2. From the above results, it was found that polyamine-based cationic polymer flocculants in particular exhibit long-term storage stability as an inorganic-organic composite one-package liquid flocculant over a wide range of LA/LB ratios. . Therefore, considering that in the past, when both were used in combination, the cationic flocculant deteriorated, storage stability was impaired, and a practical one-package type could not be obtained, the polyamine used in this example is extremely suitable. It is well understood that it is a combination. Furthermore, in terms of the viscosity of the liquid composition, the LA/LB ratio is 40/60 to 98/2, and in terms of practicality such as workability and cost, it is particularly preferably 95/5 of 50/50.
A composition of 80/20 to 95/5 may be used.

[Table] Example 2 and Comparative Example 2 A flocculation test was conducted on the one-package composite liquid composition with excellent storage stability prepared in Example 1. Coagulation test method: Collect 1000ml of raw water in a 1 liter glass beaker and stir rapidly (120rpm) using a jar tester.
At the same time, a predetermined amount of each sample was added and stirred for 3 minutes to form a floc. Then stir slowly (60 rpm)
was performed for 10 minutes to grow flocs, and the size of the resulting flocs was observed with the naked eye. After allowing this product to stand for 10 minutes, the supernatant liquid was taken from a portion approximately 2 cm below the water surface, and the turbidity, pH, alkalinity, and chromaticity were measured. Each sample prepared in Example 1 was added to natural river water with a turbidity of 102.4, a pH of 7.48, and an alkalinity of 55 mg/1.
For LA and LB, a liquid flocculant with an LA/LB mixing ratio of 90/10 was selected and added to the raw water in a range of 10 to 60 mg/flocculant, and a flocculation test was conducted for each. The results are shown in Table 3. In addition, as a comparative example, liquid inorganic flocculant FA-2, P
-1 and A-1 were similarly tested. The results are shown in Table 3. Example 3 and Comparative Example 3 Turbidity 19, PH 7.10, alkalinity 55 mg/, chromaticity 64
For LA and LB prepared in Example 1 in the same manner as in Example 2, for natural river water 1 of A similar agglutination test was carried out. The results are shown in Table 4. Liquid inorganic flocculants FA-1 and A- as comparative examples.
1 was similarly tested. The results are shown in Table 4. Example 4 and Comparative Example 4 Turbidity 20.4, PH 7.65, COD 32.9 mg/, P 14.7 mg/ obtained by activated sludge method at a human waste treatment plant
In order to perform tertiary treatment of secondary treated human waste water with a chromaticity of 250, in the same manner as in Example 2, for raw water 1, for LA and LB prepared in Example 1,
A flocculation test was similarly conducted for LA/LB mixing ratios of 95/5, 90/10, and 80/20, with addition ranges of 300 to 500 mg per raw water. In addition, in order to evaluate the effect of the tertiary treatment, COD and phosphorus ions were measured in the supernatant. The results are shown in Table 5. For comparison, liquid inorganic flocculants FA-1, A-1, BP-1 and polyamine flocculant PA-1 were also tested in the same manner.
The results are shown in Table 5. Example 5 and Comparative Example 5 For raw water in which 1.44 mg/anionic sea surfactant (MBAS) was dissolved in natural river water 1 with turbidity 19, PH 7.3, chromaticity 64, alkalinity 148 mg/1,
Regarding LA and LB prepared in Example 1, each
An agglutination test similar to that in Example 2 was conducted using a LA/LB mixing ratio of 90/10, and the supernatant was evaluated in terms of the remaining amount of MBAS (mg/) in the MBAS removal solution.
The results are shown in Table 6. As is clear from Tables 3, 4, 5, and 6, the flocculant of the present invention is effective against river water with different properties such as turbidity, PH, and alkalinity, and raw water subjected to advanced treatment at human waste treatment plants. It can be seen that an excellent flocculant effect can be obtained in one package. Furthermore, as shown in Table 5, it has an excellent dephosphorizing effect, and as shown in Table 6, it was found that the effect of removing surfactants can also be utilized as a characteristic.

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[Table] Also, regarding the LA/LB ratio and flocculant effect, the ratio is particularly preferably 80/20 to 95/5, but the third
As shown in the table, the fact that a singularity is observed especially at 90/10 can be said to be more practical from the viewpoints of stability, workability, cost, etc. Of course, the results of the above examples suggest that the composite liquid flocculant of the present invention can also be considered for industrial wastewater and sewage water.

Claims (1)

[Scope of Claims] 1. An aluminum-based or aluminum-iron-based liquid inorganic flocculant containing at least one nitrogen atom in the main chain and at least one nitrogen atom in the side chain per repeating unit, mainly consisting of a condensation polymer of dimethylamine and epichlorohydrin. _A polyamine flocculant having _one hydroxyl group is _{added as} a solid content to the _weight of _Al2O3 or _the total weight _{of Al2O3 - Fe2O3 .} A liquid flocculant composition, characterized in that a weight ratio of /polyamine flocculant is blended in an amount satisfying a range of 40/60 to 98/2. 2. The composition according to claim 1, wherein the aluminum-based liquid inorganic flocculant is a polyaluminum chloride flocculant having an Al ₂ O ₃ weight concentration in the range of 5 to 15% by weight. 3 The aluminum-iron based liquid inorganic flocculant is expressed as a three-component composition, SO ₃ , Fe ₂ O ₃ and Al ₂ O ₃ as shown in the following formula (i) When C is 12 or less S≧-0.25F+72.0 S≦100-4/3C (When A is less than 2.5) F≧4/3C-2.5 (When A is between 2.5 and 4.1+3/5C) S≦98.4-29/15C (When A is less than 4.1+3/5C) A≧0.5 F≧2 (ii) When C exceeds 12 S≧−0.25F＋72.0 S≦84 (When A is smaller than 2.5) F≧13.5 (When A is between 2.5 and 11.3) S≦75.2 (when A is greater than 11.3) A≧0.5 F≧2 [In the formula, S, F and A are SO ₃ , Fe ₂ O ₃ and Al ₂ O ₃ mol% based on the total amount of the above three components respectively,
C represents the total weight percent concentration of Fe ₂ O ₃ and Al ₂ O ₃ in the solution. ] The composition according to claim 1, which is a liquid inorganic flocculant containing a satisfactory amount of Fe ₂ O ₃ and Al ₂ O ₃ and having a total weight % concentration C in the range of 4 to 15%. .