JPH06292894A - Floccuration and separation method of organic waste water - Google Patents

Abstract

PURPOSE:To execute in high efficiency and easily and fluocculation and separation of naphthalene sulfonate formalin condensate from an organic waste water by adding the amine or the quaternary ammonium salt having the hydrocarbon of specified carbon number to the org. waste water containing the naphthalene sulfonate formalin condensate. CONSTITUTION:The amine or the quarternary ammonium salt (e.g. polyethylene imine) having the >=10C hydrocarbon is added to the org. waste water containing the naphthalene sulfonate formalin condensate. The addition of the amine to the org. waste water is 1:(0.2-10), preferably 1:(0.5-5) molar ratio of the recurring unit of the naphthalene sulfonate formalin condensate per the amine. In such a manner, the naphthalene sulfonate formalin condensate can be flocculated and separate from the org. waste water in high efficiency and easily.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for coagulating and separating organic wastewater, and more particularly to a method for coagulating and separating a naphthalenesulfonate formalin condensate contained in a large amount of organic wastewater discharged from a chemical factory. .

[0002]

BACKGROUND OF THE INVENTION Naphthalene sulfonate formalin condensates are used in large amounts as dispersants in chemical plants and the like, but after use, most of them are mixed in wastewater,
It is one of the main causes of COD deterioration.

Conventionally, as a method for treating waste water containing a naphthalene sulfonate formalin condensate, a flocculation treatment using an inorganic flocculant, a biological treatment using activated sludge, a treatment using activated carbon and the like are known.

[0004]

Of the above processing methods,
In the conventional method in which an aluminum-containing inorganic substance or the like is used as the coagulant and the coagulation treatment is performed at around pH 7, half or more of the naphthalene sulfonate formalin condensate remains in the waste water.

On the other hand, in the conventional biological treatment, only naphthalenesulfonic acid (mononuclear substance) is removed, and the naphthalenesulfonate formalin condensate is hardly treated.

[0006] The activated carbon treatment requires a large-scale apparatus, although a certain effect is recognized when it is performed on wastewater after coagulation treatment and / or biological treatment.
It has the problem of being extremely expensive.

Therefore, it has been desired to develop a method capable of removing the condensate from the waste water containing the naphthalene sulfonate formalin condensate with high efficiency and convenience.

[0008]

Means for Solving the Problems As a result of intensive investigations in view of such circumstances, the present inventors have found that by adding specific amines to an organic waste water containing a naphthalenesulfonate formalin condensate, The inventors have found that the condensate can be easily and efficiently aggregated and separated, and have completed the present invention.

That is, the present invention is characterized in that an amine or quaternary ammonium salt having a hydrocarbon having 10 or more carbon atoms is added to an organic waste water containing a naphthalene sulfonate formalin condensate. A method for coagulating and separating waste water is provided.

In the present specification, "organic wastewater" means
It mainly refers to wastewater containing an organic compound as a solution or suspension.

The amine or quaternary ammonium salt having a hydrocarbon having 10 or more carbon atoms in one molecule (chain) used in the present invention is not particularly limited, but has a molecular weight of 1
50 or more compounds, specifically

[0012]

[Chemical 1]

Dodecylamine, distearyldimethylammonium salt and the like are preferably used.

The above amines may be used alone or in combination of two or more.

The amount of amines added to the organic waste water is such that the molar ratio of the repeating unit of the naphthalene sulfonate formalin condensate to the amine is 1: 0.2 to 10, particularly 1 :.
It is preferably 0.5 to 5. If the amount of amine is less than this range, the removal effect will be reduced, while if it is more than that range, the effect will not increase and it is uneconomical.

The amines may be added as a solid,
It is preferably added as an aqueous solution. If the amines are not soluble in water, they may be dissolved in an inorganic acid such as hydrochloric acid or sulfuric acid. In this case, the addition ratio of amine and acid is preferably 0.7 to 1.3: 1.3 to 0.7 in terms of molar ratio.

The pH after addition of amines is preferably adjusted to 4.0 to 7.0 with an acid or alkali according to a conventional method.

The aggregate of the naphthalene sulfonate formalin condensate thus obtained usually forms fine flocs. In order to increase the floc, it is preferable to further add a polymer flocculant. The polymer flocculant is preferably one which effectively acts under acidic conditions. A specific example thereof is an acrylamide polymer flocculant (“N500” manufactured by Sankyo Kasei Co., Ltd.).
The polymer flocculant is usually preferably used in organic waste water at a concentration of about 5 to 30 ppm.

Aggregated flocs of the naphthalene sulfonate formalin condensate obtained by the above aggregation treatment can be separated and removed by, for example, a flotation separator, a sedimentation separator, a filtration separator, a centrifugal separator, or the like.

In the present invention, prior to the addition of the amines, (1) an aluminum salt-based inorganic coagulant is added to an organic wastewater containing a naphthalenesulfonate formalin condensate, and then (2) the wastewater. It is preferable to adjust the pH to 6.5 or less.

The aluminum salt inorganic coagulant used in the step (1) is not particularly limited,
Examples include industrially mass-produced and easily available aluminum sulfate, polyaluminum chloride, aluminum chloride, iron-containing aluminum sulfate, and the like. Of these, aluminum sulfate is particularly preferable. These aggregating agents are usually used as an aqueous solution, but those in a solid state may be used.
These aggregating agents may be used alone or in combination of two or more.

The amount of the inorganic coagulant added is not particularly limited, but it is desirable to adjust it according to the concentration of the naphthalene sulfonate formalin condensate in the waste water. Normally,
For naphthalene sulfonate formalin condensate concentration,
It is preferable to add the coagulant so that the concentration of Al ₂ O ₃ is 1/10 to 1/2.

The temperature of the organic waste water to which the aluminum salt-based inorganic coagulant is added does not usually need to be adjusted, but the coagulation efficiency may decrease at high temperatures. Therefore, when the temperature of the waste water exceeds 40 ° C. Is preferably cooled.

The pH adjustment in the above step (2) is preferably 4.0 to 5.5, more preferably 4.0 to 5.0.
And

Since all of the aggregating agents used in the present invention exhibit strong acidity, the pH is adjusted by adding an alkaline component. The alkali component is not particularly limited, but sodium hydroxide, potassium hydroxide, calcium hydroxide and the like are preferable. These may be added as solids, but are preferably added as an aqueous solution.

[0026]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto.

Example 1 An aqueous solution prepared by mixing equimolar amounts of dodecylamine and 1N hydrochloric acid in 500 ml of organic waste water containing 2,750 ppm of sodium naphthalenesulfonate formalin condensate was mixed with dodecylamine in the same weight as sodium naphthalenesulfonate formalin condensate. (At the molar ratio, the repeating unit of the condensate: dodecylamine = 1: 1.3) was added so that the mixture was stirred for 30 minutes. After standing for 3 minutes, the mixture was filtered with filter paper. The concentration of sodium naphthalenesulfonate formalin condensate in the filtrate was 130 ppm, and 95% by weight of the above compound could be removed.

Example 2 To 500 ml of organic waste water containing 2,660 ppm of sodium formalin naphthalenesulfonate condensate, 3.4 ml of aluminum sulfate aqueous solution (8.0% by weight as Al ₂ O ₃ , specific gravity 1.32) was stirred. While adding, 150 rpm
And stirred for 1 minute. The pH was then adjusted to 4.5 with 1N sodium hydroxide. Next, 10 ppm of acrylamide type polymer flocculant NP800 was added, and 50 minutes at 150 rpm for 50 minutes.
Each was stirred at rpm for 2 minutes. The flocs formed by allowing to stand for 3 minutes were allowed to settle. An aqueous solution obtained by mixing equimolar amounts of dodecylamine and 1N hydrochloric acid in the obtained aggregating solution was added to give 0.50 g of todecylamine (the same weight as the weight of sodium naphthalenesulfonate formalin condensate dissolved in water without forming flocs). , At a molar ratio of the condensate: dodecylamine = 1: 1.3). Thirty
After stirring for a minute, the mixture was allowed to stand and filtered with filter paper. The concentration of sodium naphthalene sulfonate formalin condensate in the liquid is 4
It was 84 ppm, and 82% by weight of the above compound could be removed.

Comparative Example 1 The pH was adjusted to 7.0, and the polymer flocculant was an acrylamide polymer flocculant AP52 manufactured by Diafloc Co., Ltd.
The same treatment as in Example 1 was carried out except that 0 (for pH = 7.0) was used. The concentration of sodium naphthalenesulfonate formalin condensate in the filtrate was 1,535 ppm, and the removal rate was 42% by weight.

Examples 3 to 13 and Comparative Examples 2 to 9 As shown in Table 1, the removal rate of the sodium naphthalene sulfonate formalin condensate was changed in the same manner as in Example 1 by changing the kind and addition amount of the amine. I asked. However, except for dodecylamine, amine was directly added without mixing amine and acid. The amount of amine added was represented by the number of moles of amine per repeating unit of the sodium naphthalene sulfonate formalin condensate. The results are also shown in Table 1.

[0031]

[Table 1]

As is clear from the results shown in Table 1, it is understood that all the methods of the present invention (Examples 3 to 13) bring about an excellent removal rate as compared with the comparative example.

[0033]

According to the method for coagulating and separating organic waste water of the present invention, the compound can be separated from waste water containing a naphthalene sulfonate formalin condensate with high efficiency and easily.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Toshiaki Tanaka 2-11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd.

Claims (2)

[Claims] 1. A coagulation separation of organic wastewater, characterized in that an amine having a hydrocarbon having 10 or more carbon atoms or a quaternary ammonium salt is added to the organic wastewater containing a naphthalenesulfonate formalin condensate. Method. 2. The organic wastewater containing a naphthalenesulfonate formalin condensate is added with an aluminum salt-based inorganic coagulant, and then the pH of the organic wastewater is adjusted to 6.5 or less, and then A method for coagulating and separating organic wastewater, which comprises adding the amines of 1.