JPH1076274A - Treatment method for wastewater containing high molecular emulsion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a coagulated product to be separated from water easily and promptly by a method in which an inorganic coagulant and a neutralizing agent are added as the components of a coagulating agent, and after a primary coagulated product being produced, a water-soluble high molecular carboxylic acid salt and a multivalent metal salt are added in sequence to produce a secondary coagulated product. SOLUTION: For example, a vinyl acetate copolymer emulsion diluted with water is fed into a treatment tank 1 and incorporated with an inorganic coagulant, for example, an iron (III) sulfate solution while being agitated with an agitator 2. For example, a sodium hydroxide solution as a neutralizing agent is added to adjust pH, for example, at 7.5-8.5 to produce a primary coagulated product. After that, the solution of sodium alginate, a water soluble high molecular carboxylic acid salt, is added, and after about 5min, the solution of calcium chloride, a multivalent metal salt, is added gradually. A secondary coagulation product is produced with agitation continued, water containing the secondary coagulation product of the tank 1 is introduced to a filtration apparatus 3 equipped with a disposable filter 4 to separate the secondary coagulated product from water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for treating water containing a polymer emulsion.

[0002]

2. Description of the Related Art Conventionally, wastewater containing a polymer emulsion is treated with a salting-out agent, an inorganic coagulant, an organic coagulant, or the like. Clogging is likely to occur, and there is generally a major problem in filterability.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a water treatment method capable of easily and quickly separating aggregates from water in the treatment of waste water containing a polymer emulsion. Further, the present invention provides a method for treating wastewater having high clarity of separated water.

[0004]

In order to achieve the object of the present invention, the invention of claim 1 comprises adding a flocculant (B) to waste water (A) containing a polymer emulsion to form a flocculant (C). ), The inorganic coagulant (B1) and the neutralizing agent (B2) are added as components of the coagulant (B) to form a primary coagulate (C1), A method for treating wastewater containing a polymer emulsion, comprising sequentially adding a polymer carboxylate (B3) and a polyvalent metal salt (B4) to the wastewater (A) to form a secondary aggregate (C2). Is provided.

[0005] In the present invention, the polymer emulsion includes a synthetic polymer emulsion used for adhesives, paints, inks and the like. More specific examples include a vinyl acetate polymer emulsion, a vinyl acetate copolymer emulsion, an acrylate polymer emulsion, and a styrene butadiene copolymer emulsion. Natural rubber emulsions include natural rubber emulsions,
Examples include fish meat surimi emulsion, soy milk, and milk. These emulsions are contained in various types of industrial wastewater alone or in a form coexisting with other contaminants.

In the first stage of the treatment of these emulsion wastewaters, first, an inorganic flocculant (B1) is used. Examples of inorganic coagulants include polyaluminum chloride, aluminum sulfate, iron chloride, iron sulfate, and the like. In general, since these compounds show acidity, after adding an inorganic flocculant (B1) to wastewater (A) and mixing them well, a neutralizing agent (B
In step 2), adjust the pH to about 5.0 to 10.0, preferably 6.5.
Adjust to about 8.5.

In the present invention, the order of adding the inorganic flocculant (B1) and the neutralizing agent (B2) to the wastewater (A) can be reversed. That is, the neutralizing agent (B2) is added to the wastewater (A) in advance, and then the inorganic coagulant (B1) is added.
Can also be added. Also in this case, neutralizing agent (B2)
PH of the treated water after adding the inorganic coagulant (B1) is about 5.0 to 10.0, preferably about 6.5 to 8.5.

Examples of the neutralizing agent (B2) include sodium hydroxide, sodium carbonate, potassium hydroxide, potassium carbonate, aqueous ammonia and the like.

By the above operation, the polymer emulsion is broken to form primary aggregates (C1). However, the primary agglomerate (C1) is very difficult to separate by filtration because of its small size and low flock strength. Also, the clarity of filtration is extremely poor.

Next, a water-soluble polymer carboxylate (B3) is added to the wastewater (A). Examples of the high molecular carboxylic acid include polyacrylic acid, acrylic acid copolymer, styrene / maleic acid copolymer, carboxymethyl cellulose,
Alginic acid and the like. Alginic acid is particularly preferred in terms of its performance. These compounds are generally used in the form of alkali metal salts to make them water-soluble.

Next, a polyvalent metal salt (B4) is added to the wastewater (A). Examples of the polyvalent metal salt (B4) include calcium chloride, aluminum chloride, ferric chloride, ferric sulfate, ferrous sulfate, and aluminum sulfate.

By performing these operations successively, the primary aggregates (C1) in the wastewater (A) become large in size,
Then, it changes to a secondary aggregate (C2) having a strong floc strength. The secondary agglomerates (C2) have no clogging at the time of filtration and are very easy to filter. Further, the clarity of the treated water after filtering the secondary aggregate (C2) is extremely high.

As shown in FIG. 1, the treatment operation of the polymer emulsion wastewater of the present invention can be performed in a batch operation using a single treatment tank. As shown in FIG. 2, an inorganic coagulant (B1) and a neutralizing agent (B2) are added in a first treatment tank 5 to form a primary aggregate (C1). , A water-soluble polymer carboxylate (B3) and a polyvalent metal salt (B4) are sequentially added to form a secondary aggregate (C2).

[0014]

DETAILED DESCRIPTION OF THE INVENTION An inorganic coagulant (B1) and a neutralizing agent (B2) are added to waste water (A) containing a polymer emulsion to form a primary coagulate (C1). The carboxylate (B3) and the polyvalent metal salt (B4) are sequentially added to the wastewater (A), respectively, to form secondary aggregates (C2). Separable and also high clarity of the separated water.

[0015]

【Example】

[Embodiment 1] Embodiment 1 according to the present invention will be described with reference to FIG. As a sample, the vinyl acetate copolymer emulsion was diluted with water into the treatment tank 1 of FIG.
It was adjusted to mg / L and 20 L was fed.

While stirring with the stirrer 2, the inorganic coagulant (B
After adding 20 cc of a 40% ferric sulfate solution 1), add a 10% solution of sodium hydroxide 10% as a neutralizing agent (B2) to 60%.
The pH was adjusted to 7.5 to 8.5 by adding cc to produce a primary aggregate (C1). Thereafter, 1.5 L of a 2% solution of sodium alginate as a water-soluble polymer carboxylate (B3) was added. After about 5 minutes, 250 cc of a 50% solution of calcium chloride as a polyvalent metal salt (B4) was gradually added. .

Stirring is continued for 10 minutes, and the secondary aggregates (C
2) was generated. Furthermore, the secondary aggregates (C
The water containing 2) was poured into the filtration device 3 provided with the disposable filter 4, and the secondary aggregate (C2) and water were separated. At this time, the time required for filtration was measured. The disposable filter 4 is easy to attach and detach, and the shape is cylindrical, the outer diameter of the bottom is 25 cm, the outer diameter of the upper opening is 30 cm, and the depth is 40 cm.
Was used. A nonwoven fabric made of polyethylene was used as the filter medium.

The results are shown in Table 1.

[Table 1] In the measurement of the average filtration speed in Table 1, the water containing the secondary aggregate (C 2) in the treatment tank 1 was collected, and the filtration shown on page 323 of the sewage test method (published by the Japan Sewer Association). The test was performed at normal pressure using a test apparatus. The filter media of the filtration test device is
A wire mesh having a transmission particle size of 154 μ (100 mesh) and an area of about 50 cm 2 was used.

The value of the average filtration speed is determined by the secondary aggregate (C 2)
About 500 cc of water containing water was collected, filtered under normal pressure, and expressed in terms of the amount of filtrate per unit time and unit area until 80% of the total filtrate was obtained. At this time, the collected amount is about 500
The cc corresponds to a ratio of 10 cc per 1 cm 2 of the area of the filter medium.

Regarding the criterion for the quality of the treated water in Table 1, a is when little color or suspension is observed, b is slight, and c is considerable. , D are very common.

In the first embodiment, the first processing tank 5 shown in FIG.
After the addition of the ferric sulfate solution, the sodium hydroxide solution is added to generate a primary aggregate (C1). After the sodium alginate solution is added in the second treatment tank 6, the calcium chloride solution is added. It can also be carried out in the form of a batch continuous treatment and a continuous treatment for producing a secondary aggregate (C 2). In these embodiments, substantially the same results as in Table 1 were obtained.

Comparative Example 1 The same sample as in Example 1 was used, and a 40% ferric sulfate solution 2 as an inorganic coagulant (B1) was used.
After adding 0 cc, 60 cc of a 10% sodium hydroxide solution as a neutralizing agent (B2) is added to adjust the pH to 7.5 to 8.0.
The mixture was adjusted to 5, and 50 cc of a 0.2% solution of polyacrylamide, which was a polymer coagulant, was added to form an aggregate.
The other steps were the same as in Example 1. The results are shown in Table 1.

Example 2 As a sample in the processing tank of FIG.
Dilute the water-based ink with water and adjust the solid concentration to about 5000mg.
/ L and feed 20L. In this example, as the components of the aqueous ink, those containing an azo pigment, a cyanine blue pigment, and an acrylate polymer emulsion were used.

While stirring with the stirrer 2, the inorganic coagulant (B
1) 120cc of a 10% solution of polyaluminum chloride
After the addition, sodium hydroxide 10 as a neutralizing agent (B2) is added.
% Of the solution was adjusted to pH 7.5 to 8.5 by adding 120 cc to produce a primary aggregate (C1). Thereafter, 2.5 L of a 2% solution of sodium alginate as a water-soluble polymer carboxylate (B3) was added. After about 5 minutes, 400 cc of a 50% solution of calcium chloride as a polyvalent metal salt (B4) was gradually added. . Stirring was continued for 10 minutes to form a secondary aggregate (C2).

Next, the water containing the secondary aggregates (C 2) in the treatment tank 1 is filtered into a filtration device 3 provided with a disposable filter 4.
And the secondary aggregate (C2) and water were separated. At this time, the time required for filtration was measured. Otherwise, the procedure was the same as in Example 1. The results are shown in Table 2.

[Table 2]

Comparative Example 2 The same sample as in Example 2 was used, and polyaluminum chloride 1 as an inorganic coagulant (B1) was used.
After adding 120 cc of a 0% solution, 120 cc of a 10% solution of sodium hydroxide as a neutralizing agent (B2) was added to adjust the pH to 7.5 to 8.5 to form a primary aggregate (C1). . Thereafter, 50 cc of a 0.2% aqueous solution of polyacrylamide, which is a polymer coagulant, was added to form an aggregate.
The other operations were the same as in Example 2. The results are shown in Table 2.

[0027]

That is, an object of the present invention is to provide a water treatment method capable of easily and quickly separating aggregates from water in the treatment of wastewater containing a polymer emulsion. Another object of the present invention is to provide a method for treating wastewater having high clarity of separated water.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram in the case of one processing tank showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram in the case of two processing tanks showing an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Processing tank 2 Stirrer 3 Filtration device 4 Disposable filter 5 First processing tank 6 Second processing tank

Claims (2)

[Claims] 1. A water treatment method in which a flocculant (B) is added to waste water (A) containing a polymer emulsion and a flocculant (C) is filtered off, wherein an inorganic component is used as a component of the flocculant (B). After adding a flocculant (B1) and a neutralizing agent (B2) to form a primary flocculant (C1), a water-soluble polymer carboxylate (B3) and a polyvalent metal salt (B4) are respectively discharged into wastewater (A ) To form a secondary aggregate (C2). 2. The method according to claim 1, wherein the water-soluble polymer carboxylate (B3) is a water-soluble alginate.