JP5114352B2 - Water treatment agent - Google Patents

Description

  The present invention relates to a water treatment agent used in a treatment for aggregating suspended substances in water to be treated to float and separate them.

  Conventionally, as a method for treating water such as waste water containing suspended solids (SS), a suspended separation method in which suspended solids are agglomerated and separated by sedimentation, or agglomeration floating in which suspended solids are agglomerated and separated by levitation. There are separation methods. As the coagulation flotation separation method, there are known a coagulation pressure flotation separation method in which agglomeration flotation is performed by pressurization and a coagulation normal pressure flotation separation method in which coagulation flotation is performed at normal pressure. Has been done. Compared with the sedimentation separation method, the coagulation-pressure flotation separation method has advantages that the apparatus can be miniaturized and is excellent in space saving and can be efficiently treated depending on the type of water to be treated.

  In order to treat water to be treated, such as suspended solids, by the coagulation and pressure flotation separation method, flocculants are added to the wastewater to aggregate the suspended solids in the wastewater, and flocs are formed. In general, a method is used in which fine bubbles generated by mixing pressurized water containing air with waste water and releasing the pressure to atmospheric pressure are attached to the floc to float and separate the floc.

  Conventionally, inorganic flocculants, polymer flocculants and the like have been used alone or in combination as flocculants for the flocculant treatment in the flocculent floating separation method. In addition, when treating the water to be treated by flotation separation, for the purpose of improving the flotation of flocs and improving the quality of the treated water, or for the purpose of increasing the treatment speed, a foaming surfactant or higher fatty acid is used. In some cases, an alkali metal salt is used together with a flocculant as a flotation aid (see, for example, Patent Documents 1 and 2).

JP-B-2-36313 Japanese Patent Publication No. 3-14516

  When using a surfactant as a flotation aid, depending on the destination of the treated water, the surfactant remaining in the treated water may affect the environment. On the other hand, when an alkali metal salt of a higher fatty acid as in Patent Documents 1 and 2 is used, the alkali metal salt of the higher fatty acid is highly biodegradable, so there is no problem in terms of release. Was easily oxidized and had practical problems.

  An object of the present invention is to provide a water treatment agent that is excellent in floating performance and is not easily oxidized, which is used in a process in which suspended substances in the water to be treated are aggregated and floated and separated.

  The present invention is a water treatment agent used in a treatment for aggregating suspended substances in water to be treated, and (A) an alkali metal salt of a saturated or unsaturated fatty acid having 8 to 18 carbon atoms, (B) A water treatment agent containing an antioxidant.

  The water treatment agent preferably further includes (C) a quaternary ammonium salt.

  The water treatment agent preferably further contains (D) glycols.

  In the water treatment agent, the content of the component (B), (C) or (D) with respect to the component (A) is in the range of 1% by weight to 20% by weight. preferable.

  In the water treatment agent, the component (A) is at least one selected from the sodium salt or potassium salt of lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, and linoleic acid. It is preferable.

  In the water treatment agent, the component (B) is preferably a sodium salt of ethylenediaminetetraacetic acid.

  In the water treatment agent, the component (C) is preferably alkylbenzylammonium hydrochloride.

In the water treatment agent, the component (D) is preferably a glycol containing a structure represented by the following structural formula (X).

(X)

  The present invention also relates to a water treatment agent used in a treatment for aggregating suspended substances in water to be treated to float and separate them, (A) an alkali metal salt of a saturated or unsaturated fatty acid having 8 to 18 carbon atoms. 0.1 to 20% by weight, (B) 0.05 to 5% by weight of antioxidant, (C) 0.05 to 5% by weight of quaternary ammonium salt, and (D) glycols to 0%. 0.05 to 5% by weight of a water treatment agent.

  In the present invention, by containing an alkali metal salt of a saturated or unsaturated fatty acid having 8 to 18 carbon atoms and an antioxidant, it is used in a treatment for aggregating suspended substances in the water to be treated for floating separation. In addition, it is possible to provide a water treatment agent that has excellent floating performance and is not easily oxidized.

  Embodiments of the present invention will be described below. This embodiment is an example for carrying out the present invention, and the present invention is not limited to this embodiment.

  As a result of intensive studies, the present inventors have found the following composition and have provided a water treatment agent for levitation treatment that is excellent in practical use and performance.

  The water treatment agent according to the embodiment of the present invention is used in a treatment for aggregating suspended substances in raw water to float and separate, and (A) an alkali metal salt of a saturated or unsaturated fatty acid having 8 to 18 carbon atoms; And (B) an antioxidant. The water treatment agent according to the present embodiment is for the purpose of improving the treatment water quality by improving the floatability of flocs formed by the addition of a flocculant or the treatment speed when treating the water to be treated by flotation separation. It is used as a flotation aid for purposes. In the aqueous solution containing the alkali metal salt of the higher fatty acid, the water treatment agent is superior in floating performance by containing an antioxidant in addition to the alkali metal salt of the higher fatty acid mainly for improving the floatability of flocs. Even if it exists, it is hard to be oxidized and can be used practically.

  The alkali metal salt of a saturated fatty acid having 8 to 18 carbon atoms is not particularly limited, but sodium such as caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, etc. Salt, potassium salt, lithium salt, etc. are mentioned.

  The alkali metal salt of an unsaturated fatty acid having 8 to 18 carbon atoms is not particularly limited, but one unsaturated double bond is present in the molecule such as myristoleic acid, palmitoleic acid, oleic acid, elaidic acid and vaccenic acid. Monounsaturated fatty acids having monounsaturated fatty acids, linoleic acid, etc. Diunsaturated fatty acids having two unsaturated double bonds in the molecule, α-linolenic acid, γ-linolenic acid, eleostearic acid, etc. Examples thereof include sodium salts such as triunsaturated fatty acids having three bonds, potassium salts, and lithium salts.

  These may be used individually by 1 type and may be used in combination of 2 or more type. A combination of an alkali metal salt of a saturated fatty acid having 8 to 18 carbon atoms and an alkali metal salt of an unsaturated fatty acid having 8 to 18 carbon atoms may be used.

  Of these, sodium or potassium salts of lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, and linoleic acid are preferred from the viewpoint of formulation, performance, environment, etc., and lauric acid, oleic acid, and linoleic acid are preferred. Sodium salt or potassium salt is more preferred.

  Although the compounding quantity of (A) component in a water treatment agent is not specifically limited, The range of 0.1-20 weight% is preferable with respect to the total weight of a water treatment agent on preparation, 0.5-10 weight% The range of is more preferable.

  Antioxidants include reducing agents such as L-ascorbic acid, erythorbic acid and their sodium salts, butylhydroxyanisole, butylhydroxytoluene, propyl gallate, ethylenediaminetetraacetic acid (EDTA), ethylenediamine-N, N′-disucci Acid (EDDS), nitrilotriacetic acid (NTA), diethylenetriaminepentaacetic acid (DTPA), L-aspartic acid diacetic acid (ASDA), L-glutamic acid diacetic acid (GLDA), hydroxyethylethylenediaminetriacetic acid (HEDTA), methylglycine Keys such as acetic acid (MGDA), glycol ether diamine tetraacetic acid (GEDTA), triethylenetetramine hexaacetic acid (TTHA), hydroxyethyliminodiacetic acid (HIDA) and their sodium salts, potassium salts, hydrates, etc. And the like over preparative agent (sequestrant). These may be used individually by 1 type and may be used in combination of 2 or more type.

  Among these, a chelating agent (metal sequestering agent) is preferable from the viewpoints of high antioxidant effect and low reactivity with other components contained in the water treatment agent. From the viewpoint of cost and formulation stability, ethylenediamine is preferred. The sodium salt of tetraacetic acid is more preferred, and tetrasodium ethylenediaminetetraacetic acid is more preferred. By using a chelating agent, it is possible to make a formulation without significantly reducing the performance of the main component (A) while exhibiting an antioxidant effect.

  Although the compounding quantity of (B) component in a water treatment agent is not specifically limited, The range of 0.05-5 weight% is preferable with respect to the total weight of a water treatment agent, 0.1-1.0 weight% A range is more preferred. Considering the stability as a water treatment agent, the amount of component (B) is preferably in the range of 1% by weight to 20% by weight with respect to component (A), preferably 2% by weight to 10% by weight. The range of is more preferable.

  The water treatment agent according to this embodiment may contain (C) a quaternary ammonium salt in addition to (A) an alkali metal salt of a saturated or unsaturated fatty acid having 8 to 18 carbon atoms and (B) an antioxidant. Furthermore, (D) glycols may be included. The water treatment agent contains a quaternary ammonium salt in addition to an alkali metal salt of a higher fatty acid, so that the floating performance is excellent, and even an aqueous solution containing an alkali metal salt of a higher fatty acid is not easily oxidized and is not easily spoiled. Can be used practically. In addition, the water treatment agent contains glycols in addition to alkali metal salts of higher fatty acids, so that it has excellent floating performance and is not easily oxidized even in an aqueous solution containing alkali metal salts of higher fatty acids. It is difficult to freeze even in places where the temperature is low, and it can be used practically.

The quaternary ammonium salt is mainly used as a preservative, for example, alkyl ammonium hydrochloride such as higher alkyl ammonium hydrochloride having an alkyl group having 8 to 30 carbon atoms, benzalkonium chloride (C ₆ H ₅ CH ₂ N Alkylbenzylammonium hydrochlorides such as higher alkylbenzylammonium hydrochlorides having an alkyl group having 8 to 30 carbon atoms such as ⁺ (CH ₃ ) ₂ R · Cl ⁻ (R = C ₈ H _{17 to} C ₁₈ H ₃₇ ) Examples include salt. These may be used individually by 1 type and may be used in combination of 2 or more type.

  Of these, alkylbenzylammonium hydrochloride is preferred, and benzalkonium chloride is more preferred from the standpoint of formulation, performance, and environment. By using alkylbenzylammonium hydrochloride, it can be formulated without significantly reducing the performance of component (A), which is the main component.

  Although the compounding quantity of (C) component in a water treatment agent is not specifically limited, The range of 0.05-5 weight% is preferable with respect to the total weight of a water treatment agent, 0.1-1.0 weight% A range is more preferred. Considering the stability as a water treatment agent, the amount of component (C) is preferably in the range of 1% by weight to 20% by weight with respect to component (A), preferably 2% by weight to 10% by weight. The range of is more preferable.

  Glycols are mainly used as antifreeze agents, and examples include ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, and polyethylene glycol. These may be used individually by 1 type and may be used in combination of 2 or more type.

  Of these, glycols such as diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, and polyethylene glycol including the structure represented by the following structural formula (X) from the viewpoint of formulation, performance, environment, and the like. It is preferable. By using glycols having a structure represented by the following structural formula (X), formulation can be made without significantly reducing the performance of the component (A) as a main component.

(X)

  Although the compounding quantity of (D) component in a water treatment agent is not specifically limited, The range of 0.05-5 weight% is preferable with respect to the total weight of a water treatment agent, 0.1-1.0 weight% A range is more preferred. Considering the stability as a water treatment agent, the amount of component (D) is preferably in the range of 1% by weight to 20% by weight with respect to component (A), preferably 2% by weight to 10% by weight. The range of is more preferable.

  Water etc. are mentioned as a solvent used for the water treatment agent which concerns on this embodiment.

  The water treatment agent according to this embodiment includes (A) an alkali metal salt of a saturated or unsaturated fatty acid having 8 to 18 carbon atoms, (B) an antioxidant, (C) a quaternary ammonium salt, and (D) glycols. In addition, it has excellent levitation performance and is not easily oxidized even in an aqueous solution containing an alkali metal salt of a higher fatty acid, and is not easily frozen even in cold places such as cold regions. Is possible. In particular, the water treatment agent comprises (A) at least one selected from sodium salt or potassium salt of lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid and linoleic acid, and (B) ethylenediaminetetraacetic acid. An alkali metal salt of a higher fatty acid that has excellent floating performance when it contains a sodium salt, (C) an alkylbenzylammonium hydrochloride, and (D) a glycol containing the structure represented by the structural formula (X). Even if it is the aqueous solution containing, it is hard to be oxidized, it is hard to rot, and it is hard to freeze in places with low temperature, such as a cold region, and it can be used practically.

  In addition to the component (A) and the component (B), the component (C) and the component (D) that are included as necessary, the water treatment agent according to the present embodiment includes, for example, an antifoaming agent, A foaming agent or the like may be included.

  The water treatment agent according to this embodiment can be preferably applied to the treatment by agglomeration, pressure flotation separation of various types of treated water such as industrial wastewater discharged from various factories and the like, river water, well water, and industrial water. is there. For example, after a coagulation treatment in which a floc is formed by adding a flocculant such as an inorganic flocculant to the water to be treated to aggregate suspended substances in the water to be treated to form a floc, the water treatment agent according to this embodiment is treated with the water to be treated. In addition to mixing the pressurized water containing air with the water to be treated and releasing it to atmospheric pressure, fine bubbles generated by adhering to the flocs are caused to float, and the flocs are floated and separated to perform separation Good. The water treatment agent according to the present embodiment can also be applied to treatment by atmospheric pressure flotation separation or the like. Moreover, it is applicable also to the floating separation process which does not pass through an aggregation process. The water treatment agent according to the present embodiment is a stable water treatment agent that can realize high-speed, high-performance, and economical treatment with respect to the coagulation flotation separation process such as the above-described coagulation pressure flotation separation process.

  Hereinafter, although an example and a comparative example are given and the present invention is explained more concretely in detail, the present invention is not limited to the following examples.

(Examples 1 to 10)
As Examples 1-10, each material was mixed with the compounding ratio shown in Table 1, the composition was prepared, and the following four evaluation items were evaluated. The results are shown in Table 1. In addition, the numerical value in a composition of Table 1 shows weight% with respect to the total weight of a water treatment agent.

(1) Evaluation of antiseptic properties Using industrial water, diluted water of a composition adjusted to pH = 7 with hydrochloric acid or sodium hydroxide aqueous solution, a 10,000 mg / L solution was cultured at 30 ° C. for 48 hours, and the number of general bacteria The increase of was investigated. For the general bacterial count measurement, Sun Eye Bio Checker TTC (manufactured by Sanai Oil Co., Ltd.) was used. The following evaluation criteria were set for the degree of increase in the number of bacteria from the initial value.
(Evaluation criteria)
○: No increase in the number of bacteria △: The number of bacteria increased by 1 to 2 digits ×: The number of bacteria increased by 3 digits or more

(2) Antioxidant Evaluation The prepared composition was opened to the atmosphere in a place exposed to direct sunlight, and the change over time for 1 week was investigated. The following evaluation criteria were established for changes in appearance.
(Evaluation criteria)
○: Maintains transparency △: Some cloudiness is observed ×: Completely cloudy

(3) -5 ° C Stability Evaluation The prepared composition was stored in a -5 ° C constant temperature bath for 14 days, and the following evaluation criteria were provided for appearance changes.
(Evaluation criteria)
○: No freezing after 14 days Δ: Freezing within 3-14 days ×: Freezing within 3 days

(4) Levitation performance retention evaluation The aggregation / pressurization levitation test was performed by the jar tester + flotation tester method shown below. As the water to be treated, simulated waste water was used in which 100 mg / L of powder for JIS Z 8901 test (type 11) was added to Sagamihara well water and stirred and mixed. After adding a predetermined concentration of inorganic coagulant (PAC) as a jar test, adjust the pH to 7 with an aqueous sodium hydroxide solution (adjusted to 5%), add the predetermined concentration of the composition shown in Table 1, and mix with stirring. A test was conducted to measure the turbidity of the treated water. The following evaluation criteria were provided for the mathematical formula represented by the following formula (I).
[(Processed water turbidity (degree) by blank-treated water turbidity (degree) by composition) / (treated water turbidity (degree) by blank-treated water turbidity (degree) by aqueous solution of fatty acid salt only)] × 100 (I)
(Evaluation criteria)
○: Over 90 (%) △: 60-90 (%)
X: Less than 60 (%)

(Jar tester + Flotation tester method)
[1] Dispense Sagamiharai water into a 500 mL beaker.
[2] Add 200 mg / L of JIS Z 8901 test powder (type 11) and stir at 150 rpm for 60 seconds.
[3] Add 250 mg / L of polyaluminum chloride (PAC) and stir at 150 rpm for 60 seconds.
[4] Adjust pH to 7 with aqueous sodium hydroxide solution (prepared to 5%).
[5] Add 50 mg / L of the composition shown in Table 1, and stir at 150 rpm for 60 seconds.
[6] Transfer water containing agglomerated floc to a flotation tester and add pressurized water. A pressure levitation separation tester manufactured by Miyamoto Seisakusho was used as the flotation tester. The pressurized water conditions were as follows: pressurized condition = 0.2 MPa, pressurized water ratio to treated water system = 20%.
[7] After reacting for 2 minutes, the turbidity of the treated water is measured.

(Comparative Examples 1-4)
As Comparative Examples 1 to 4, the compositions shown in Table 1 not containing an antioxidant (EDTA · 4Na) were prepared, and the above four evaluation items were evaluated in the same manner as in Examples 1 to 10. The results are shown in Table 1. In addition, in “(4) Floating performance maintenance evaluation” of Comparative Examples 1 and 2, the raw water turbidity before the test was 135 degrees, the treated water turbidity without the chemical (blank) was 55 degrees, and Comparative Example 1 was 25 degrees. Example 2 resulted in 5.0 degrees.

  The water treatment agents of Examples 1 to 10 were practically usable and excellent in flying performance and antioxidant properties. On the other hand, the water treatment agents of Comparative Examples 1 to 4 cannot achieve both floating performance and antioxidant property and cannot be used practically. The water treatment agents of Examples 1 to 10 are stable water treatment agents, and high-speed, high-performance and economical treatment can be realized with respect to the flocculation / floating / separation treatment of water to be treated.

Claims (9)

A water treatment agent used in a treatment for flocculating and separating floating substances in water to be treated,
(A) an alkali metal salt of a saturated or unsaturated fatty acid having 8 to 18 carbon atoms;
(B) an antioxidant;
A water treatment agent comprising: The water treatment agent according to claim 1,
Further, (C) a water treatment agent comprising a quaternary ammonium salt. The water treatment agent according to claim 1 or 2,
Furthermore, (D) the water treatment agent characterized by including glycols. The water treatment agent according to any one of claims 1 to 3,
A water treatment agent, wherein the content of each component (B), (C) or (D) with respect to the component (A) is in the range of 1 to 20% by weight. The water treatment agent according to any one of claims 1 to 4,
The component (A) is at least one selected from sodium salt or potassium salt of lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid and linoleic acid, . It is a water treatment agent given in any 1 paragraph of Claims 1-5,
The water treatment agent, wherein the component (B) is a sodium salt of ethylenediaminetetraacetic acid. The water treatment agent according to claim 2,
The water treating agent, wherein the component (C) is alkylbenzylammonium hydrochloride. The water treatment agent according to claim 3,
The water treatment agent, wherein the component (D) is a glycol containing a structure represented by the following structural formula (X).

(X) A water treatment agent used in a treatment for flocculating and separating floating substances in water to be treated,
(A) 0.1 to 20% by weight of an alkali metal salt of a saturated or unsaturated fatty acid having 8 to 18 carbon atoms,
(B) 0.05 to 5 wt% antioxidant,
(C) 0.05 to 5% by weight of a quaternary ammonium salt,
(D) 0.05 to 5% by weight of glycols,
A water treatment agent comprising: