JP7465699B2 - Water treatment composition and water treatment method - Google Patents

Description

The present invention relates to a water treatment composition for suppressing biological adhesion in water systems, and a water treatment method using the water treatment composition.

Various problems caused by fungi and algae can occur in various water systems, such as cooling water systems, hot and cold water systems, pure water production process water systems, wastewater recovery process water systems, paper pulp process water systems, and dust collection water systems. For example, in cooling water systems, problems such as a decrease in heat exchange efficiency due to slime generation in heat exchangers, and microbial corrosion occurring at the bottom of slime accumulations in pipes, etc. are known.

A commonly used method for suppressing damage caused by such fungi and algae is to add a bactericide composition to an aqueous system. As the bactericide, organic bactericides such as isothiazolone compounds and oxidizing agent-based bactericides such as hypochlorous acid are used. Of these, oxidizing agent-based bactericide compositions are often advantageous in terms of bactericidal effect and cost, and therefore these oxidizing agent-based bactericide compositions are widely used in various aqueous systems. An example of an oxidizing agent-based bactericide composition is chlorosulfamic acid, as described in Patent Documents 1 and 2.

When these oxidizing agent-based bactericide compositions and scale inhibitors are used together, multiple chemical tanks and liquid delivery pumps are required, which creates the problem of laborious management. In addition, the oxidizing agent-based bactericide composition and scale inhibitor must be supplied to the water system in an appropriate ratio. For example, if the oxidizing agent-based bactericide composition is added in excess of the scale inhibitor, its oxidizing power may cause the scale inhibitor to decompose, resulting in the formation of scale.

For this reason, it is desirable to supply the highly oxidizing agent-based disinfectant composition and the scale inhibitor to the water system in as constant a ratio as possible, and it is most desirable to combine the oxidizing agent-based disinfectant composition and the scale inhibitor into a single agent.

For example, Patent Document 3 presents a one-component slime prevention composition that contains a chlorine-based oxidizing agent such as sodium hypochlorite, a sulfamic acid compound, and an anionic polymer that is a scale inhibitor, and has a pH of 12 or higher. However, in the slime prevention composition of Patent Document 3, the chlorine-based oxidizing agent is reacted with sulfamic acid to stabilize it as chlorosulfamic acid, which increases the stability of the composition, but there is a problem in that the oxidizing power of the slime inhibitor, i.e., slime inhibition performance, is significantly reduced.

JP 2006-206608 A Patent No. 3832399 International Publication No. 2003/096810

The object of the present invention is to provide a water treatment composition that is a one-component formulation containing a scale inhibitor while suppressing a significant decrease in the slime inhibition performance of an oxidizing agent-based bactericidal composition, and a water treatment method that uses the water treatment composition.

The present invention is a water treatment agent composition comprising an iodine-based oxidizing agent, at least one of an iodide and an alkaline agent, and a scale inhibitor, wherein the iodine-based oxidizing agent is at least one of iodine, iodate, and periodate, the iodide is at least one of sodium iodide, potassium iodide, lithium iodide, ammonium iodide, and hydroiodic acid, and the alkaline agent is at least one of an alkali hydroxide and an alkali carbonate .

（１）
（式（１）中、Ｒ^１は水素原子またはメチル基を表し、Ｘ^１は水素原子、１価もしくは２価の金属原子、アンモニウム基または有機アンモニウム基を表す。）

（２）
（式（２）中、Ｒ^２とＲ^３はそれぞれ独立に水素原子またはメチル基を表し、Ｘ^２とＸ^３はそれぞれ独立に水素原子、１価もしくは２価の金属原子、アンモニウム基または有機アンモニウム基を表す。）

（３）
（式（３）中、Ｒ^４は水素原子またはメチル基を表し、Ｘ^４は炭素数１～１０のアルキルスルホン酸基もしくはその塩、または、炭素数６～１０のアリールスルホン酸基もしくはその塩を表し、塩の場合は１価もしくは２価の金属塩、アンモニウム塩または有機アンモニウム塩である。）

（４）
（式（４）中、Ｒ^５は水素原子またはメチル基を表し、Ｘ^５とＸ^６はそれぞれ独立に水素原子または炭素数１～１０のアルキル基を表すが、少なくとも一方が炭素数１～１０のアルキル基である。）

（５）
（式（５）中、Ｒ^６は水素原子またはメチル基を表し、Ｘ^７は炭素数１～１０のアルキル基である。）

（６）
（式（６）中、Ｒ^７は水素原子またはメチル基を表し、Ｘ^８は炭素数１～１０のアルキル基である。）

（７）
（式（７）中、Ｙは、水素原子またはアルカリ金属原子を表し、Ｚは、－ＣＯＮＨＣ（ＣＨ_３）_２ＣＨ_２ＳＯ_３Ｎａを表し、ｈ，ｌ，ｍ，ｎはそれぞれ０または正の整数であり、ｈ＋ｌ＋ｍ＋ｎは、１～１００の整数である。）

（８）
（式（８）中、Ｙは、水素原子またはアルカリ金属原子を表し、ｍ，ｎはそれぞれ０または正の整数であり、ｍ＋ｎは、１～１００の整数である。）

（９）
（式（９）中、Ｙ^１およびＹ^２は、それぞれ独立に水素原子またはアルカリ金属原子を表す。）

（１０）
（式（１０）中、Ｙ^３およびＹ^４は、それぞれ独立に水素原子またはアルカリ金属原子を表す。） In the water treatment agent composition, the scale inhibitor is preferably at least one of a polymer containing a monomer unit of formula (1), a polymer containing a monomer unit of formula (2), a copolymer containing a monomer unit of formula (1) and a monomer unit of formula (3), a copolymer containing a monomer unit of formula (1), a monomer unit of formula (3), and a monomer unit of formula (4), a copolymer containing a monomer unit of formula (2), a monomer unit of formula (5), and a monomer unit of formula (6), a phosphinocarboxylic acid copolymer of formula (7), a bis(poly-2-carboxyethyl)phosphinic acid of formula (8), a 2-phosphonobutane-1,2,4-tricarboxylic acid of formula (9) and a salt thereof, and a 1-hydroxyethylidene-1,1-diphosphonic acid of formula (10) and a salt thereof.

(1)
(In formula (1), R ¹ represents a hydrogen atom or a methyl group, and X ¹ represents a hydrogen atom, a monovalent or divalent metal atom, an ammonium group, or an organic ammonium group.)

(2)
(In formula (2), ^R2 and ^R3 each independently represent a hydrogen atom or a methyl group, and ^X2 and ^X3 each independently represent a hydrogen atom, a monovalent or divalent metal atom, an ammonium group, or an organic ammonium group.)

(3)
(In formula (3), R ⁴ represents a hydrogen atom or a methyl group, and X ⁴ represents an alkylsulfonic acid group having 1 to 10 carbon atoms or a salt thereof, or an arylsulfonic acid group having 6 to 10 carbon atoms or a salt thereof, and in the case of a salt, it is a monovalent or divalent metal salt, an ammonium salt, or an organic ammonium salt.)

(4)
(In formula (4), ^R5 represents a hydrogen atom or a methyl group, and ^X5 and ^X6 each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, provided that at least one of them is an alkyl group having 1 to 10 carbon atoms.)

(5)
(In formula (5), ^R6 represents a hydrogen atom or a methyl group, and ^X7 represents an alkyl group having 1 to 10 carbon atoms.)

(6)
(In formula (6), ^R7 represents a hydrogen atom or a methyl group, and ^X8 represents an alkyl group having 1 to 10 carbon atoms.)

(7)
(In formula (7), Y represents a hydrogen atom or an alkali metal atom, Z represents _--CONHC ( _CH.sub.3 ) _{.sub.2CH.sub.2SO.sub.3Na} , h _, l, m, and n each represent 0 or a positive integer, and h+l+m+n represents an integer from 1 to 100.)

(8)
(In formula (8), Y represents a hydrogen atom or an alkali metal atom, m and n each represent 0 or a positive integer, and m+n represents an integer from 1 to 100.)

(9)
(In formula (9), ^Y1 and ^Y2 each independently represent a hydrogen atom or an alkali metal atom.)

(10)
(In formula (10), ^Y3 and ^Y4 each independently represent a hydrogen atom or an alkali metal atom.)

In the water treatment composition, it is preferable that the pH of the water treatment composition is less than 12.

When the water treatment composition contains both the iodine-based oxidizing agent and the iodide, it is preferable that the mass ratio of the iodide to the iodine-based oxidizing agent is 1.2 or more.

The present invention is a water treatment method for treating water using the water treatment agent composition.

The present invention provides a one-component water treatment composition containing a scale inhibitor while preventing a significant decrease in the slime inhibition performance of an oxidizing agent-based bactericidal composition, and a water treatment method using the water treatment composition.

The following describes an embodiment of the present invention. This embodiment is an example of implementing the present invention, and the present invention is not limited to this embodiment.

The water treatment agent composition according to this embodiment is a composition containing an iodine-based oxidizing agent, at least one of an iodide and an alkaline agent, and a scale inhibitor. The water treatment agent composition according to this embodiment preferably contains an iodine-based oxidizing agent, an iodide, an alkaline agent, and a scale inhibitor, in terms of the solubility of the iodine-based oxidizing agent, not significantly increasing the pH of the formulation, and the like. The water treatment agent composition according to this embodiment may further contain water.

The inventors have discovered that by combining an iodine-based oxidizing agent and at least one of an iodide and an alkali agent with a scale inhibitor, a water treatment composition containing a scale inhibitor can be obtained as a single agent while suppressing a significant decrease in the slime inhibition performance of the oxidizing agent-based bactericidal composition (i.e., a significant decrease in oxidizing power). Furthermore, when the water treatment composition according to this embodiment is used, the pH of the water to be treated is not significantly increased even when it is added to the water to be treated.

Examples of iodine-based oxidizing agents include iodine (I ₂ ), iodates, periodates, etc. Among these, iodine is preferred from the viewpoints of bactericidal performance, cost, etc.

Examples of iodides include sodium iodide, potassium iodide, lithium iodide, ammonium iodide, and hydroiodic acid. Of these, potassium iodide is preferred from the standpoint of solubility, etc.

Examples of alkaline agents include alkali hydroxides such as sodium hydroxide and potassium hydroxide, and alkali carbonates such as sodium carbonate and potassium carbonate. Of these, alkali hydroxides are preferred, and potassium hydroxide is preferred from the standpoint of the solubility of the iodine-based oxidizing agent. The alkaline agent may be used as an aqueous solution rather than in a solid form.

Of the iodides and alkaline agents, iodides such as potassium iodide are preferred from the standpoint of the solubility of the iodine-based oxidizing agent, and it is more preferable to include both an iodide and an alkaline agent.

Examples of scale inhibitors include polymers containing monomer units of the following formula (1), polymers containing monomer units of the following formula (2), copolymers containing monomer units of the following formula (1) and monomer units of the following formula (3), copolymers containing monomer units of the following formula (1), monomer units of the following formula (3), and monomer units of the following formula (4), copolymers containing monomer units of the following formula (2), monomer units of the following formula (5), and monomer units of the following formula (6), phosphinocarboxylic acid copolymers of the following formula (7), bis(poly-2-carboxyethyl)phosphinic acid of the following formula (8), 2-phosphonobutane-1,2,4-tricarboxylic acid and its salts of the following formula (9), 1-hydroxyethylidene-1,1-diphosphonic acid and its salts of the following formula (10), aminotrimethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid, etc.

As the scale inhibitor, a polymer consisting of a monomer unit of the following formula (1), a polymer consisting of a monomer unit of the following formula (2), a binary copolymer consisting of a monomer unit of the following formula (1) and a monomer unit of the following formula (3), a terpolymer consisting of a monomer unit of the following formula (1), a monomer unit of the following formula (3), and a monomer unit of the following formula (4), a terpolymer containing a monomer unit of the following formula (2), a monomer unit of the following formula (5), and a monomer unit of the following formula (6), a phosphinocarboxylic acid copolymer of the following formula (7), a bis(poly-2-carboxyethyl)phosphinic acid of the following formula (8), a 2-phosphonobutane-1,2,4-tricarboxylic acid of the following formula (9) and its salt, and a 1-hydroxyethylidene-1,1-diphosphonic acid of the following formula (10) and its salt are preferred.

Among these, the polymer containing the monomer unit of the following formula (1), the polymer containing the monomer unit of the following formula (2), the copolymer containing the monomer unit of the following formula (1) and the monomer unit of the following formula (3), the copolymer containing the monomer unit of the following formula (1), the monomer unit of the following formula (3) and the monomer unit of the following formula (4), the copolymer containing the monomer unit of the following formula (2), the monomer unit of the following formula (5) and the monomer unit of the following formula (6), the phosphinocarboxylic acid copolymer of the following formula (7), the bis(poly-2-carboxyethyl)phosphinic acid of the following formula (8), the 2-phosphonobutane-1,2,4-tricarboxylic acid and its salt of the following formula (9), and the 1-hydroxyethylidene-1,1-diphosphonic acid and its salt of the following formula (10) usually function as a metal corrosion inhibitor for ferrous metals in addition to functioning as a scale inhibitor.

（１）
（式（１）中、Ｒ^１は水素原子またはメチル基を表し、Ｘ^１は水素原子、１価もしくは２価の金属原子、アンモニウム基または有機アンモニウム基を表す。）

(1)
(In formula (1), R ¹ represents a hydrogen atom or a methyl group, and X ¹ represents a hydrogen atom, a monovalent or divalent metal atom, an ammonium group, or an organic ammonium group.)

（２）
（式（２）中、Ｒ^２とＲ^３はそれぞれ独立に水素原子またはメチル基を表し、Ｘ^２とＸ^３はそれぞれ独立に水素原子、１価もしくは２価の金属原子、アンモニウム基または有機アンモニウム基を表す。）

(2)
(In formula (2), ^R2 and ^R3 each independently represent a hydrogen atom or a methyl group, and ^X2 and ^X3 each independently represent a hydrogen atom, a monovalent or divalent metal atom, an ammonium group, or an organic ammonium group.)

（３）
（式（３）中、Ｒ^４は水素原子またはメチル基を表し、Ｘ^４は炭素数１～１０のアルキルスルホン酸基もしくはその塩、または、炭素数６～１０のアリールスルホン酸基もしくはその塩を表し、塩の場合は１価もしくは２価の金属塩、アンモニウム塩または有機アンモニウム塩である。）

(3)
(In formula (3), R ⁴ represents a hydrogen atom or a methyl group, and X ⁴ represents an alkylsulfonic acid group having 1 to 10 carbon atoms or a salt thereof, or an arylsulfonic acid group having 6 to 10 carbon atoms or a salt thereof, and in the case of a salt, it is a monovalent or divalent metal salt, an ammonium salt, or an organic ammonium salt.)

（４）
（式（４）中、Ｒ^５は水素原子またはメチル基を表し、Ｘ^５とＸ^６はそれぞれ独立に水素原子または炭素数１～１０のアルキル基を表すが、少なくとも一方が炭素数１～１０のアルキル基である。）

(4)
(In formula (4), ^R5 represents a hydrogen atom or a methyl group, and ^X5 and ^X6 each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, provided that at least one of them is an alkyl group having 1 to 10 carbon atoms.)

（５）
（式（５）中、Ｒ^６は水素原子またはメチル基を表し、Ｘ^７は炭素数１～１０のアルキル基である。）

(5)
(In formula (5), ^R6 represents a hydrogen atom or a methyl group, and ^X7 represents an alkyl group having 1 to 10 carbon atoms.)

（６）
（式（６）中、Ｒ^７は水素原子またはメチル基を表し、Ｘ^８は炭素数１～１０のアルキル基である。）

(6)
(In formula (6), ^R7 represents a hydrogen atom or a methyl group, and ^X8 represents an alkyl group having 1 to 10 carbon atoms.)

（７）
（式（７）中、Ｙは、水素原子またはアルカリ金属原子を表し、Ｚは、－ＣＯＮＨＣ（ＣＨ_３）_２ＣＨ_２ＳＯ_３Ｎａを表し、ｈ，ｌ，ｍ，ｎはそれぞれ０または正の整数であり、ｈ＋ｌ＋ｍ＋ｎは、１～１００の整数である。）

(7)
(In formula (7), Y represents a hydrogen atom or an alkali metal atom, Z represents _--CONHC ( _CH.sub.3 ) _{.sub.2CH.sub.2SO.sub.3Na} , h _, l, m, and n each represent 0 or a positive integer, and h+l+m+n represents an integer from 1 to 100.)

（８）
（式（８）中、Ｙは、水素原子またはアルカリ金属原子を表し、ｍ，ｎはそれぞれ０または正の整数であり、ｍ＋ｎは、１～１００の整数である。）

(8)
(In formula (8), Y represents a hydrogen atom or an alkali metal atom, m and n each represent 0 or a positive integer, and m+n represents an integer from 1 to 100.)

（９）
（式（９）中、Ｙ^１およびＹ^２は、それぞれ独立に水素原子またはアルカリ金属原子を表す。）

(9)
(In formula (9), ^Y1 and ^Y2 each independently represent a hydrogen atom or an alkali metal atom.)

（１０）
（式（１０）中、Ｙ^３およびＹ^４は、それぞれ独立に水素原子またはアルカリ金属原子を表す。）

(10)
(In formula (10), ^Y3 and ^Y4 each independently represent a hydrogen atom or an alkali metal atom.)

In addition, the organic ammonium salts in formulas (1) to (3) are preferably, for example, alkylammonium groups or (hydroxy)alkylammonium groups having an alkyl group or hydroxyalkyl group having 1 to 4 carbon atoms.

Examples of the monovalent or divalent metal salts in formulas (1) to (3) include sodium salts, potassium salts, calcium salts, magnesium salts, etc.

When ^X4 in formula (3) is an alkylsulfonic acid group or a salt thereof, the alkyl group is preferably an alkyl group having 1 to 8 carbon atoms. When ^X4 is an arylsulfonic acid group or a salt thereof, the aryl group is preferably an aryl group or arylalkyl group having 6 to 10 carbon atoms.

The alkyl groups in formulas (4) to (6) are preferably alkyl groups having 1 to 8 carbon atoms.

The weight ratio of the monomer units in a binary copolymer consisting of the monomer units of formula (1) and the monomer units of formula (3) is preferably 1-99:99-1.

The weight ratio of the monomer units in a terpolymer consisting of the monomer units of formula (1), the monomer units of formula (3), and the monomer units of formula (4) is preferably 1-98:1-98:1-98.

The weight ratio of the monomer units in a terpolymer consisting of the monomer units of formula (2), the monomer units of formula (5), and the monomer units of formula (6) is preferably 1-98:1-98:1-98.

The weight-average molecular weight of the polymer containing the monomer units of formulas (1) to (6) is preferably in the range of 500 to 100,000. If the weight-average molecular weight is less than 500 or exceeds 100,000, the scale inhibition performance may decrease.

The weight average molecular weight of the phosphinocarboxylic acid copolymer of formula (7) is preferably in the range of 500 to 100,000. If the weight average molecular weight is less than 500 or exceeds 100,000, the scale inhibition performance may decrease. The weight average molecular weight of the bis(poly-2-carboxyethyl)phosphinic acid of formula (8) is preferably in the range of 500 to 100,000. If the weight average molecular weight is less than 500 or exceeds 100,000, the scale inhibition performance may decrease.

As the alkali metal atom in the formulae (7), (8), (9) and (10), a sodium atom or a potassium atom is preferable, and a sodium atom is more preferable. 2-phosphonobutane-1,2,4-tricarboxylic acid in which Y ¹ and Y ² in the formula (9) are hydrogen atoms is the following compound.

1-Hydroxyethylidene-1,1-diphosphonic acid in which Y ³ and Y ⁴ in the formula (10) are hydrogen atoms is the following compound.

The total iodine concentration in the water treatment agent composition according to this embodiment is preferably in the range of 0.7% to 5.0% by weight based on the total amount of the composition. If the total iodine concentration is less than 0.7% by weight based on the total amount of the composition, the control of biofouling may be poor, and if it exceeds 5.0% by weight, the stability of the formulation, such as storage stability, may be impaired.

The formulation pH of the water treatment agent composition according to this embodiment is preferably less than 12, more preferably in the range of 3 to less than 12, and even more preferably in the range of 5 to 10. If the formulation pH is 12 or more, the pH of the water to be treated increases, making it easier for scale components to precipitate. If the formulation pH is less than 3, the pH of the water to be treated decreases, making iron-based and copper-based metals more susceptible to corrosion.

In the water treatment composition according to the present embodiment, when both an iodine-based oxidizing agent and an iodide are contained, the mass ratio of the iodide to the iodine-based oxidizing agent (iodide/iodine-based oxidizing agent) is preferably 1.0 or more, more preferably 1.2 or more, and even more preferably 1.7 to 5.0. If the ratio is less than 1.0, the amount of insoluble matter may increase, and if it exceeds 5.0, the formulation stabilization effect commensurate with the amount of the mixture may not be obtained, making it uneconomical.

When the water treatment composition according to this embodiment contains both an iodine-based oxidizing agent and an iodide, the mass ratio of the alkaline agent to the sum of the iodine-based oxidizing agent and iodide [alkaline agent/(iodine-based oxidizing agent+iodide)] is preferably less than 0.4, and more preferably less than 0.3, in order to improve the storage stability of iodine in the formulation. If the ratio exceeds 0.4, the amount of ineffective consumption of the iodine-based oxidizing agent component increases, and the iodine concentration may decrease during storage of the formulation.

In the water treatment composition according to this embodiment, when the water treatment composition contains only an alkaline agent among iodide and an alkaline agent, the pH of the water treatment composition immediately after formulation is preferably 8.4 to 10.0, and more preferably 9.0 to 9.7. If the pH is less than 8.4, the amount of insoluble matter may increase, and if it exceeds 10.0, the iodine concentration in the formulation may decrease.

<Method of producing water treatment agent composition>
The water treatment agent composition according to the present embodiment is obtained, for example, by mixing an iodine-based oxidizing agent, at least one of an iodide and an alkaline agent, and a scale inhibitor, and is obtained, for example, by mixing an iodine-based oxidizing agent, at least one of an iodide and an alkaline agent, a scale inhibitor, and water.

<Water treatment method using water treatment agent composition>
The water treatment agent composition according to the present embodiment can be used in various water systems such as cooling water systems, cold and hot water systems, pure water production process water systems, wastewater recovery process water systems, paper pulp process water systems, dust collection water systems, etc. The water treatment agent composition according to the present embodiment can be used, for example, in water treatment methods such as water treatment for industrial water systems such as cooling water, and pipe cleaning with advanced biological adhesion contamination.

The total iodine concentration in the water system to which the water treatment composition according to this embodiment has been added is preferably 0.1 to 150 mg/L. If the total iodine concentration in the water system to which the water treatment composition has been added is less than 0.1 mg/L, it may not be possible to obtain a sufficient slime inhibition effect, and if it is more than 150 mg/L, it may corrode metal materials in the system.

The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

<Examples 1 to 18>
In the examples, the formulations were prepared by adding the ingredients in the composition (wt%) and order (adding from top to bottom) shown in Tables 1 to 4. The formulations were prepared in a PTFE (polytetrafluoroethylene) container by cooling to room temperature (25°C) or below and adding each drug while stirring with a stirrer.

In Tables 1 to 4, "PAA" is an acrylic acid homopolymer (weight average molecular weight approximately 4,500), "AABI" is an acrylic acid-based binary copolymer of acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid (weight average molecular weight approximately 4,500), "AATER" is an acrylic acid-based terpolymer of acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, and alkylacrylamide (weight average molecular weight approximately 4,500), "PMAA" is a maleic acid homopolymer (weight average molecular weight approximately 1,000), and "PMAVA" is a maleic acid-based terpolymer of maleic acid, ethyl acrylate, and vinyl acetate (weight average molecular weight approximately 1,000). "PCABI" is a phosphinocarboxylic acid copolymer of formula (7) (the average value of h+l+m+n is about 16), "BCAP" is bis(poly-2-carboxyethyl)phosphinic acid of formula (8) (the average value of m+n is about 16), "PBTC" is 2-phosphonobutane-1,2,4-tricarboxylic acid, and "HEDP" is 1-hydroxyethylidene-1,1-diphosphonic acid. The potassium hydroxide used was a special grade reagent manufactured by Kanto Chemical Co., Ltd., and the potassium iodide and iodine used were special grade reagents manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.

The pH was measured under the following conditions.
Electrode type: Glass electrode type pH meter: IOL-30 type, manufactured by DKK-TOA Electrode calibration: Two-point calibration was performed using Kanto Chemical's phthalate pH (4.01), standard solution (type 2), and the same company's neutral phosphate pH (6.86) standard solution (type 2) Measurement temperature: 25°C
Measurement value: Immerse the electrode in the measurement solution, and the value after stabilization is the measurement value, which is the average of three measurements.

In the examples, the free halogen concentration and total halogen concentration were measured by diluting the sample 10,000 times and using a HACH multi-item water quality analyzer DR/3900, using the available chlorine measurement method (DPD (diethyl-p-phenylenediamine) method). The free iodine concentration and total iodine concentration were calculated from the molecular weights of chlorine and iodine after determining the free chlorine concentration and total chlorine concentration. In addition, the total iodine concentration of each water treatment composition was measured after storing it at 25°C for 10 days in the dark, and the remaining rate relative to the total iodine concentration immediately after formulation was calculated. In addition, the presence or absence of insoluble matter was visually confirmed for the compositions in Tables 1, 2, 3, and 4.

In the composition of the embodiment, an iodine-based oxidizing agent, which is an oxidizing agent-based slime inhibitor, and a specific polymer are mixed at a pH of less than 10, thereby suppressing a significant decrease in the slime-inhibiting performance of the inorganic slime inhibitor (significant decrease in oxidizing power) while forming a single agent. In addition, for the compositions containing both an iodine-based oxidizing agent and an iodide in Tables 1 and 2, when the mass ratio of iodide to the iodine-based oxidizing agent is 1.2 or more, the iodine-based oxidizing agent and the polymer can be combined into a single agent without generating insoluble matter, and a composition containing a high concentration of iodine, with a total iodine concentration of 2.8% by weight or more immediately after formulation, was obtained. For the compositions containing only an alkali agent among the iodide and alkali agents in Tables 3 and 4, when the pH immediately after formulation is 9.0 to 9.7, a composition containing a high concentration of iodine, with a total iodine concentration of 0.6% by weight or more immediately after formulation, was obtained. In addition, in all of the examples, the proportion of free iodine in the total iodine was 90% or more, and it was found that the iodine was able to be formulated into a single agent while still maintaining a high oxidizing power.

In this way, a one-component water treatment composition containing a scale inhibitor while suppressing a significant decrease in the slime inhibition performance of the oxidizing agent-based bactericidal composition was obtained, and a water treatment method using the water treatment composition was provided.

Claims (5)

An iodine-based oxidizing agent;
Iodide ,
An alkaline agent ,
A scale inhibitor;
Including,
the iodine-based oxidizing agent is at least one of iodine, an iodate, and a periodate;
the iodide is at least one of sodium iodide, potassium iodide, lithium iodide, ammonium iodide, and hydroiodic acid;
The water treatment composition , wherein the alkaline agent is at least one of an alkali hydroxide and an alkali carbonate . The water treatment composition according to claim 1,
The scale inhibitor is a water treatment agent composition characterized in that it is at least one of a polymer containing a monomer unit of formula (1), a polymer containing a monomer unit of formula (2), a copolymer containing a monomer unit of formula (1) and a monomer unit of formula (3), a copolymer containing a monomer unit of formula (1), a monomer unit of formula (3), and a monomer unit of formula (4), a copolymer containing a monomer unit of formula (2), a monomer unit of formula (5), and a monomer unit of formula (6), a phosphinocarboxylic acid copolymer of formula (7), a bis(poly-2-carboxyethyl)phosphinic acid of formula (8), a 2-phosphonobutane-1,2,4-tricarboxylic acid and a salt thereof of formula (9), and a 1-hydroxyethylidene-1,1-diphosphonic acid and a salt thereof of formula (10).
(1)
(In formula (1), R ¹ represents a hydrogen atom or a methyl group, and X ¹ represents a hydrogen atom, a monovalent or divalent metal atom, an ammonium group, or an organic ammonium group.)
(2)
(In formula (2), ^R2 and ^R3 each independently represent a hydrogen atom or a methyl group, and ^X2 and ^X3 each independently represent a hydrogen atom, a monovalent or divalent metal atom, an ammonium group, or an organic ammonium group.)
(3)
(In formula (3), R ⁴ represents a hydrogen atom or a methyl group, and X ⁴ represents an alkylsulfonic acid group having 1 to 10 carbon atoms or a salt thereof, or an arylsulfonic acid group having 6 to 10 carbon atoms or a salt thereof, and in the case of a salt, it is a monovalent or divalent metal salt, an ammonium salt, or an organic ammonium salt.)
(4)
(In formula (4), ^R5 represents a hydrogen atom or a methyl group, and ^X5 and ^X6 each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, provided that at least one of them is an alkyl group having 1 to 10 carbon atoms.)
(5)
(In formula (5), ^R6 represents a hydrogen atom or a methyl group, and ^X7 represents an alkyl group having 1 to 10 carbon atoms.)
(6)
(In formula (6), ^R7 represents a hydrogen atom or a methyl group, and ^X8 represents an alkyl group having 1 to 10 carbon atoms.)
(7)
(In formula (7), Y represents a hydrogen atom or an alkali metal atom, Z represents _--CONHC ( _CH.sub.3 ) _{.sub.2CH.sub.2SO.sub.3Na} , h _, l, m, and n each represent 0 or a positive integer, and h+l+m+n represents an integer from 1 to 100.)
(8)
(In formula (8), Y represents a hydrogen atom or an alkali metal atom, m and n each represent 0 or a positive integer, and m+n represents an integer from 1 to 100.)
(9)
(In formula (9), ^Y1 and ^Y2 each independently represent a hydrogen atom or an alkali metal atom.)
(10)
(In formula (10), ^Y3 and ^Y4 each independently represent a hydrogen atom or an alkali metal atom.) The water treatment composition according to claim 1 or 2,
The water treatment agent composition has a pH of less than 12. The water treatment composition according to any one of claims 1 to 3,
The water treatment agent composition, when it contains both the iodine-based oxidizing agent and the iodide, is characterized in that a mass ratio of the iodide to the iodine-based oxidizing agent is 1.2 or more. A water treatment method comprising treating water with the water treatment agent composition according to any one of claims 1 to 4.