JPH10195203A - Production of polymer aqueous solution - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing an aqueous polymer solution that does not lower the coagulation power of the water-soluble polymer comprising a quaternized dimethylaminoethyl acrylate and acrylamide which are used for dehydration or concentration of organic sludge. SOLUTION: A dispersion of fine particles of a water-soluble polymer with particle sizes of <=10μm is stirred with a high-speed rotation agitation machine of >=2,000rpm to apply a shear force to the dispersion to fine liquid particles. Then, the dispersion is allowed to stand for hours to form an aqueous solution, desirably in a polymer concentration of 0.7-3wt.% thereby producing the objection aqueous solution that does not lower the coagulation power.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a dispersion medium which is useful as a polymer flocculant or a papermaking agent, wherein the dispersion medium is an oily liquid containing a surfactant or an aqueous salt solution which does not dissolve finely particulate water-soluble polymers. The present invention relates to a method for producing an aqueous polymer solution, which provides a novel method for dissolving a dispersion in which fine particles of a water-soluble polymer having a particle size of 10 μm or less are dispersed. The aqueous polymer solution is added to organic sludge to cause coagulation and is effectively used for sludge dewatering or sludge concentration.

[0002]

2. Description of the Related Art As a conventional general method for producing an aqueous solution of a polymer flocculant or the like, a stirrer of about 100 to 300 rpm is used, water is poured into a dissolution tank, and a polymer concentration of 0.1 to 0.2% by weight (rare). 0.5% by weight) and adding it to sludge or the like at that concentration. In this method, not only the installation area of the dissolution equipment becomes large, but also in the case of a water-soluble polymer having a composition containing a quaternized product of dimethylaminoethyl acrylate and acrylamide, the polymer is liable to be deteriorated and the coagulation ability is reduced. There is.

[0003]

It is an object of the present invention to improve the above-mentioned dissolving method used so far and to provide an inexpensive method for preparing an aqueous polymer solution having a small installation area and free from polymer deterioration.

[0004]

The present inventor can easily prepare a high-concentration aqueous solution by subjecting a dispersion of the fine particles of the water-soluble polymer to shearing in water to form fine droplets. The inventors have found that the high-concentration polymer aqueous solution is less deteriorated, and have accomplished the present invention.

According to the first aspect of the present invention, the particle size is 10 μm.
A dispersion of fine particles of the following water-soluble polymer was
This is a method for producing a polymer aqueous solution, characterized in that an aqueous solution of a water-soluble polymer is prepared by applying shearing in water to form fine droplets by using a stirrer rotating at a high speed of 00 rpm or more.

According to a second aspect of the present invention, the particle size is 10 μm.
The dispersion medium of the following dispersion of fine particles of a water-soluble polymer is an oil-based liquid containing a surfactant or a salt aqueous solution that does not dissolve the fine-particle water-soluble polymer. This is a method for producing an aqueous polymer solution.

According to a third aspect of the present invention, the particle size is 10 μm.
A dispersion of fine particles of the following water-soluble polymer was
The production of the aqueous polymer solution according to claim 1 or 2, wherein the aqueous solution is subjected to shearing in water to form fine liquid droplets by a high-speed rotation stirrer of 00 rpm or more, and then left to stand. Is the law.

According to a fourth aspect of the present invention, the water-soluble polymer forming the fine particles is a polymer having a composition containing a quaternized dimethylaminoethyl acrylate and acrylamide. A method for producing an aqueous polymer solution according to claim 3.

The invention of claim 5 of the present invention is characterized in that the concentration of the polymer in the aqueous solution of the water-soluble polymer produced through the above operation is 0.7 to 3% by weight. 5. A method for producing a polymer aqueous solution according to item 4.

The invention according to claim 6 of the present invention is characterized in that the water-soluble polymer aqueous solution produced through the above operation is added to the organic sludge without dilution. This is a method for producing an aqueous polymer solution.

[0011] The invention of claim 7 of the present invention is characterized in that the aqueous solution of the water-soluble polymer produced through the above operation is diluted with water in a pipe by an in-line mixer or the like and then added to the organic sludge. A method for producing a polymer aqueous solution according to any one of Items 1 to 5.

[0012]

DETAILED DESCRIPTION OF THE INVENTION A first limitation of the present invention is that a particle size of 10
An aqueous solution of a water-soluble polymer is obtained by subjecting a dispersion of fine particles of a water-soluble polymer having a particle size of μm or less to shearing in water to form fine droplets by using a high-speed stirrer having a rotation speed of 2000 rpm or more. This is a method for producing a polymer aqueous solution. According to a second limitation of the present invention, in the method for producing a polymer aqueous solution according to claim 1, a dispersion medium of a dispersion of fine particles of a water-soluble polymer having a particle size of 10 μm or less contains an oily liquid containing a surfactant or It is a salt aqueous solution that does not dissolve the fine particulate water-soluble polymer. A third limitation of the present invention is that the method for producing a polymer aqueous solution according to claim 1 or 2 has a particle diameter of 10 μm.
A dispersion of fine particles of the following water-soluble polymer was
It is characterized by leaving a standing time after passing through an operation of forming fine droplets by shearing in water with a stirrer rotating at a high speed of 00 rpm or more. A fourth limitation of the present invention is that
4. The method for producing a polymer aqueous solution according to claim 1, wherein the water-soluble polymer forming fine particles is a polymer having a composition containing quaternized dimethylaminoethyl acrylate and acrylamide. I do. A fifth limitation of the present invention is that in the method for producing a polymer aqueous solution according to any one of claims 1 to 4, the concentration of the polymer in the aqueous solution of the water-soluble polymer produced through the above operation is 0.7 to 3% by weight.
It is characterized by being. A sixth limitation of the present invention is that, in the method for producing a polymer aqueous solution according to claims 1 to 5, the water-soluble polymer aqueous solution produced through the above operation is added to the organic sludge without dilution. Features.
A seventh limitation of the present invention is that in the method for producing a polymer aqueous solution according to any one of claims 1 to 5, the water-soluble polymer aqueous solution produced through the above operation is diluted with water in a pipe by an inline mixer or the like. Later, it is added to organic sludge.

[0013] The shape of commercially available water-soluble polymers can be various, such as powders, granular solids, dispersions, and aqueous solutions. Above all, although the use of the dispersion is increasing in recent years as it is easy to dissolve, using a stirrer of about 100 to 300 rpm using a dissolution tank that has conventionally dissolved the granular solid, In the method of dissolving water in a polymer concentration of 0.1 to 0.2% by weight (rarely 0.5% by weight), the stirring power is weak. There were many. In the present invention, for example, water and a polymer dispersion are continuously supplied to a small tank of about 10 to 50 liters, and a two-pole motor directly connected type (a brush type can be used, but it takes a long time to perform maintenance work in terms of durability). The high-speed stirrer described in (1) above makes high-speed stirring to produce fine polymer droplets, so that the appearance of mamako can be completely prevented. Specific uses of the above water-soluble polymers include sludge dehydrating agents. The target sludge is anaerobic digested sludge by anaerobic digestion of organic substances, mixed raw sludge of sewage, and excess sludge of the activated sludge method of various organic wastewaters. (Including metal hydroxide-containing sludge). Examples of the sludge dewatering machine include a belt press,
Examples include a decanter, a filter press, a screw press, and a vacuum dehydrator. If necessary, it can be used in combination with an inorganic coagulant such as ferric chloride, polyiron sulfate, polyaluminum chloride, and a sulfuric acid band, and other organic polymer coagulants. Other specific uses of the above water-soluble polymer include a paper retention improver, which is effective not only for improving the filler retention but also the fixing retention of the size, and has the effect of improving the water repellency of the formed paper. Other specific uses of the above water-soluble polymer include a drainage improver for paper, and the drainage enhancer is intended to improve the papermaking speed, and is mainly used in papermaking of paperboard, The purpose of this invention is to increase the drying performance by improving the water drainage and water squeezing.

When fine droplets of a water-soluble polymer are prepared as described above and left in water, they are completely dissolved in a stationary state. In the conventional method, it was necessary to stir for a long time until the mamako was completely dissolved, and the performance was degraded due to the breakage of the polymer chains due to the stirring. There is no. The dispersion medium of the dispersion liquid of the fine particles of the water-soluble polymer is an oily liquid containing a surfactant or an aqueous salt solution that does not dissolve the fine-particle water-soluble polymer.
Since it exists as fine particles having a size of μm or less, the power for forming the fine droplets does not need to be large.

The most preferred water-soluble polymer to which the present invention is applied is a polymer having a composition containing quaternary dimethylaminoethyl acrylate and acrylamide. The monomers and other monomers may be copolymerized,
Anionic monomers such as acrylic acid and acrylamide 2-methylpropanesulfonic acid, and crosslinking monomers such as methylenebisacrylamide can also be copolymerized. The water-soluble polymer is widely used for the above-mentioned various uses, and although its utility is highly evaluated, there is a disadvantage that the polymer is liable to deteriorate. In the present invention, it can be used for various purposes by dissolving in a short time because it does not make mamako,
It can be used before polymer degradation begins. on the other hand,
The present inventors have found that when the above-mentioned commercially available polymer is maintained at a high concentration, there is a tendency that the polymer deteriorates little, and the polymer concentration in the aqueous solution of the water-soluble polymer is 0.7 to 3% by weight. It has been found that holding in state is appropriate. Such a tendency is remarkable in the case of using activated sludge treated water or the like for polymer dissolution in terms of the charge of dissolved water. Storing at a high concentration also has the advantage of requiring a small storage tank volume, and can greatly reduce the installation area for both dissolution equipment and chemical injection equipment. As described above, the present invention requires a small amount of power, can easily produce a high-concentration aqueous solution, and can sufficiently exhibit these advantages. When such a high-concentration aqueous solution is added under a high shearing force such as a decanter, the high-concentration aqueous solution may be poured as it is, and under a moderate coagulation and stirring condition such as a belt press, a screw press, and a filter press, the high-concentration aqueous solution may be in-line mixed. After diluting with water in a pipe by the method described above, it can be added to organic sludge or the like.

[0016]

EXAMPLES Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist.

(Polymer Composition) A commercially available water-in-oil emulsion type polymer having the composition shown in Table 1 was subjected to the test.

[0018]

[Table 1]

(Example 1) A polymer emulsion and well water were continuously supplied to a 30-liter cylindrical dissolution tank so that each sample had the polymer dissolution concentration of the example described in Table 2, and was eccentrically mounted. Shear was applied by a 0.5-horsepower turbon mixer (two-pole motor direct-coupled stirrer) manufactured by Tsukishima Kikai Co., Ltd., and then stored in a storage tank. When a part was taken out and observed, it was completely dissolved after 10 minutes. The solution was allowed to stand overnight, and the next day, mixed sludge (PH; 6.8, SS; 15200 mg) of excess sludge and tertiary sludge in the night soil treatment plant
/ L, loss on ignition; 69.5%) as the target sludge and IHI
A dehydration test was conducted by injecting the drug in the machine without dilution into a decanter manufactured by the company. Table 2 shows the results.

[0020] (Comparative Example 1) Each sample as consisting polymer dissolution concentration in Table 2 Comparative Example, polymer emulsion with stirring water well water into dissolving tank of 10 m ³ at beam 5 horsepower Sukuryuupera stirrer Dispensed and dissolved. One hour later, a portion was taken out and observed. As a result, undissolved matter still remained in a mamako state, and it took 3 hours for complete dissolution. This solution was left overnight and subjected to the same dehydration test as in Example 1. Table 2 shows the results.

[0021]

[Table 2]

(Example 2) A polymer emulsion and well water were continuously supplied to a 30-liter cylindrical dissolution tank so that each sample had the polymer dissolution concentration of the example described in Table 3, and was eccentrically attached. Shear was applied by a 0.5-horsepower turbon mixer (two-pole motor direct-coupled stirrer) manufactured by Tsukishima Kikai Co., Ltd., and then stored in a storage tank. When a part was taken out and observed, it was completely dissolved after 10 minutes. This solution was left overnight, and the same sludge and the same decanter used in the test in Example 1 the next day were diluted with water to a polymer concentration of 0.25% using an in-line mixer and injected into the in-machine medicine to conduct a dehydration test. Done. Table 3 shows the results.

Comparative Example 2 This is the same as Comparative Example 1. Table 3 shows the results.

[0024]

According to the dissolution method of the present invention, the water-soluble polymer dispersion can be dissolved in a short period of time, and it can be easily dissolved at a high concentration. There is an advantage that the installation area can be greatly reduced, and the economic effect is great.

[Table 3]

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Claims (7)

[Claims] 1. A method in which a dispersion of fine particles of a water-soluble polymer having a particle size of 10 μm or less is subjected to shearing in water to form fine droplets by a high-speed stirrer having a rotation speed of 2000 rpm or more. And preparing an aqueous solution of a water-soluble polymer. 2. The dispersion medium of a dispersion of fine particles of a water-soluble polymer having a particle size of 10 μm or less is an oily liquid containing a surfactant or a salt aqueous solution that does not dissolve the fine-particle water-soluble polymer. The method for producing a polymer aqueous solution according to claim 1. 3. A dispersion of fine particles of a water-soluble polymer having a particle diameter of 10 μm or less is subjected to shearing in water by a high-speed stirrer having a rotation speed of 2000 rpm or more to form fine droplets, followed by operation. 3. The method for producing a polymer aqueous solution according to claim 1, wherein a leaving time is allowed. 4. The high-molecular-weight polymer according to claim 1, wherein the water-soluble polymer forming the fine particles is a polymer having a composition containing a quaternized product of dimethylaminoethyl acrylate and acrylamide. A method for producing a molecular aqueous solution. 5. The aqueous polymer solution according to claim 1, wherein the concentration of the polymer in the aqueous solution of the water-soluble polymer produced through the operation is 0.7 to 3% by weight. Manufacturing method. 6. The method for producing an aqueous polymer solution according to claim 1, wherein the aqueous solution of the water-soluble polymer produced through the above operation is added to the organic sludge without dilution. 7. The water-soluble polymer aqueous solution produced through the above operation is diluted with water in a pipe by an in-line mixer or the like, and then added to organic sludge.
A method for producing a polymer aqueous solution according to claim 5.