JP2001047044A - Method for treating water containing endocrine disrupting substances - Google Patents

Abstract

(57) [Summary] [Object] To provide a method for treating endocrine disrupting substance-containing water which can be detoxified at low cost by selectively decomposing and removing endocrine disrupting substances contained in a trace amount in water. An endocrine disrupting substance-containing water is passed through a hydrophobic membrane having a catalytic function to treat endocrine disrupting substance-containing water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for treating water containing endocrine disrupting substances. More specifically, the present invention relates to a method for treating endocrine disrupting substance-containing water that can be detoxified at low cost by selectively decomposing and removing endocrine disrupting substances contained in a trace amount in water.

[0002]

2. Description of the Related Art In recent years, it has been suspected that endogenous endocrine disrupting chemicals, generally called environmental hormones, are involved in reproductive disorders of wildlife found in many areas. Interest in materials is growing. An endocrine disrupting substance is a substance, such as an exogenous endocrine disrupting chemical substance, a living hormone or a synthetic hormone, which disturbs the endocrine system when entering the body of an organism and adversely affects the health and ecosystem such as reproductive disorders. Among these, exogenous endocrine disrupting chemicals were identified by the Environment Agency in 1997 in the Interim Report on the Study Group on the Problem of Exogenous Endocrine Disrupting Chemicals as 67 substances suspected to be endogenous endocrine disrupting chemicals. The substance (group) is listed. That is, dioxins, polychlorinated biphenyls (PC
B), polybrominated biphenyls (PBB), hexachlorobenzene (HCB), pentachlorophenol (PC
P) 2,4,5-trichlorophenoxyacetic acid, 2,4-
Dichlorophenoxyacetic acid, amitrol, atrazine,
Arachlor, simazine, hexachlorocyclohexane, ethyl parathion, carbaryl, chlordane, oxychlordane, trans-nonachlor, 1,2-dibromo-
3-chloropropane, DDT, DDE, DDD, quercene, aldrin, endrin, tildoline, endosulfan (benzoepine), heptachlor, heptachlorepoxide, malathion, mesomil, methoxychlor, mylex, nitrofen, toxaphen, tributyltin, triphenyltin, trifluralin, alkylphenol (C5), nonylphenol, 4-octylphenol, bisphenol A, di-2-phthalic acid
Ethylhexyl, butylbenzyl phthalate, di-n-butyl phthalate, dicyclohexyl phthalate, diethyl phthalate, benzo (a) pyrene, 2,4-dichlorophenol, di-2-ethylhexyl adipate, benzophenone, 4-nitrotoluene, Octachlorostyrene, Aldicarb, Benomyl, Keepon (chlordecone), Manzeb (Mancozeb), Maneb, Methyram, Metribuzin, Dipermethrin, Esfenvalerate, Fenvalerate, Permethrin, Vinclozolin, Zineb,
It is a substance or substance group of diram, dipentyl phthalate, dihexyl phthalate, dipropyl phthalate, dimer and trimer of styrene, and n-butylbenzene. Endocrine disruptors are industrially produced and used in a wide range of areas, such as resin materials, plasticizers, surfactants, dyes and their raw materials, and pesticides. Some are naturally occurring, some are produced in nature,
It has been pointed out that it is widely distributed in water, drainage, rivers, lakes, marshes, seawater, soil, groundwater, sediment, etc., and has become a major social problem. When these substances are taken into a living body, they act on the human body and other organisms, such as thyroid hormone, sex hormone, and adrenocorticotropic hormone. Even small amounts have been reported to have an effect. Sufficient scientific knowledge has not yet been obtained regarding the mechanism of action of endocrine disrupting substances, and at present, no environmental regulations have been imposed on endocrine disrupting substances at home and abroad. The substance (s) listed in the above interim report of the research group were not identified as exogenous endocrine disrupting chemicals. Therefore, future research results may identify substances (group) that are considered endocrine disrupting substances in addition to these substances (group). Conventionally, biodegradation, oxidative decomposition with ozone, hydrogen peroxide, and the like have been studied and proposed as techniques for removing harmful organic compounds present in water. Examples of biological treatment for the purpose of decomposing and removing specific harmful substances include decomposition treatment with specific fungi and bacteria, and decomposition treatment with a mixture of microorganisms such as activated sludge acclimated with a specific substance. These treatments are excellent when the substance to be treated is specified, but when there are many kinds of compounds in the water, especially when endocrine disrupting substances are present, they are all efficiently removed. It is difficult. Also, mg
Mixed microorganisms and isolates that have been acclimated and separated in an aqueous solution containing a decomposition target compound at the level of 1 / liter do not necessarily have a strong affinity for treatment of the decomposition target compound contained at an extremely low concentration of the μg / liter level. I can't say. As a treatment method using an oxidizing agent, a method using a strong oxidizing agent such as ozone or hydrogen peroxide has been studied. They have a strong oxidizing power and are capable of decomposing various kinds of compounds. However, compared to the mg / liter level, μ
At an extremely low concentration of g / liter, the amount of the oxidizing agent required per amount of the target compound increases, which is not economically preferable.

[0003]

SUMMARY OF THE INVENTION The present invention is to selectively decompose and remove endocrine disrupting substances contained in a trace amount in water,
An object of the present invention is to provide a method for treating endocrine disrupting substance-containing water that can be made harmless at low cost.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, added an oxidizing agent or a reducing agent to water containing an endocrine-disrupting substance to thereby improve the catalytic function. It has been found that the endocrine disrupting substance contained in the water can be selectively decomposed and removed by passing water through the hydrophobic membrane, and the present invention has been completed based on this finding. That is, the present invention provides (1) a method for treating endocrine disrupting substance-containing water, which comprises passing the endocrine disrupting substance-containing water through a hydrophobic membrane having a catalytic function, and (2) an endocrine disrupting substance. (1) The method for treating water containing an endocrine disrupting substance according to (1), wherein the oxidizing agent is added to the water containing the oxidizing agent, and the water is passed through a hydrophobic membrane having a catalytic function. The method for treating endocrine disrupting substance-containing water according to (2), wherein the water is added and passed through a hydrophobic membrane having a catalytic function under ultraviolet irradiation. (4) The endocrine disrupting substance-containing water is treated under ultraviolet irradiation. (1) The method for treating water containing an endocrine disrupting substance according to (1), wherein the water is passed through a hydrophobic membrane having a catalytic function. (5) A hydrophobic agent having a catalytic function is added to the water containing an endocrine disrupting substance. The method for treating endocrine disrupting substance-containing water according to (1), wherein the water is passed through the membrane, and 6) Treatment of endocrine disrupting substance-containing water according to item (1), wherein the hydrophobic film having a catalytic function is obtained by supporting a metal or metal oxide catalyst on a hydrophobic film having a hydrophilic surface. Method.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The method for treating endocrine disrupting substance-containing water according to the present invention is specified as the above-mentioned substance suspected as an exogenous endocrine disrupting chemical at present, or as an exogenous endocrine disrupting chemical in the future. And water containing substances that may disrupt the endocrine system, such as living hormones and synthetic hormones. In the method of the present invention, an endocrine disrupting substance is contained in an amount of 1 μg / liter to 5 mg.
1 / liter and suitable for treating water containing hydrophobic endocrine disrupting substances. The pH of the endocrine disrupting substance-containing water to which the method of the present invention is applied is not particularly limited, and it can be applied in a wide range of pH 1 to 13, but is particularly preferably applied in a pH range of 5 to 9. The material of the hydrophobic film used in the method of the present invention is not particularly limited, and examples thereof include a polypropylene film, a polydimethylsiloxane film, a poly (4-methylpentene-1) film, a poly (2,6-dimethylphenylene oxide) film, and a polyfluorinated film. A vinylidene fluoride film, a polytetrafluoroethylene film, and the like can be given. When an oxidizing agent is added to the endocrine disrupting substance-containing water, it is preferable to use a polytetrafluoroethylene film or a polyvinylidene fluoride film having excellent oxidation resistance. The pore size of the hydrophobic membrane used in the method of the present invention is preferably from 0.01 to 2 μm, more preferably from 0.05 to 1 μm. The form of the hydrophobic membrane used in the method of the present invention is not particularly limited, and examples thereof include a flat membrane, a spiral membrane, and a hollow fiber. When irradiating the endocrine disrupting substance-containing water with ultraviolet rays, flat membranes and hollow fibers can be suitably used.

There is no particular limitation on the method of imparting a catalytic function to the hydrophobic film used in the method of the present invention. For example, a film can be formed by kneading an oxidation-reduction catalyst into a film material, or
An oxidation-reduction catalyst can also be supported on a hydrophobic film whose surface has been modified to be hydrophilic by etching or the like. Among them, a method in which a redox catalyst is supported on a hydrophobic film having a hydrophilic surface can be preferably used. The method for making the surface of the hydrophobic film hydrophilic is not particularly limited. For example, when the hydrophobic film is a polytetrafluoroethylene film, a coating layer of a fluorine compound having a hydrophilic group is formed on the film surface. Alternatively, a hydrophilic monomer can be graft-polymerized on the film surface. Examples of the fluorine compound having a hydrophilic group that forms the coating layer include, for example, a hydrolyzate of a copolymer of tetrafluoroethylene and vinyl acetate, and examples of the hydrophilic monomer to be graft-polymerized include: , N-vinylpyrrolidone and the like. The surface of the hydrophobic membrane does not need to be entirely hydrophilic, and it is sufficient that about 10 to 60% of the membrane surface is hydrophilic, and the catalyst is supported on the hydrophilized portion. The effects of the present invention are exhibited. As an oxidation-reduction catalyst to be supported on a hydrophobic membrane having a hydrophilic surface, for example,
Metal catalysts such as palladium, platinum, ruthenium, rhodium, iridium, iron, nickel, manganese, and copper, and metal oxide catalysts such as titania, alumina, zirconia, nickel peroxide, copper peroxide, and cobalt peroxide may be mentioned. it can. The amount of the catalyst supported on the hydrophobic membrane is not particularly limited, and is, for example, 0.05 to 20 per weight of the hydrophobic membrane.
% By weight. The method for supporting the catalyst is not particularly limited. For example, the catalyst can be supported by immersing the hydrophobic film in an aqueous solution containing a catalyst metal. When the hydrophobic film is a heat-resistant film such as a polytetrafluoroethylene film or a polyvinylidene fluoride film, the film is immersed in a solution containing a catalyst and then heated at 100 to 200 ° C. for 2 hours.
By heating for 0 to 30 minutes, or by heating the solution while immersing the membrane in the above solution, the bonding strength of the catalyst to the membrane can be increased.

In the method of the present invention, the oxidizing agent added to the endocrine disrupting substance-containing water is not particularly limited, and examples thereof include hydrogen peroxide, ozone, oxygen, chlorine, and persulfuric acid. By oxidative decomposition, it is possible to remove all endocrine disrupting substances except inorganic substances such as cadmium and lead. In the case of oxidative decomposition, nickel, cobalt, palladium, platinum, iron, manganese and other simple substances, oxides,
It is preferable to use a peroxide catalyst. The amount of the oxidizing agent is not particularly limited, but is preferably 1 to 3 times the stoichiometric amount necessary for oxidatively decomposing the entire amount of endocrine disrupting substance in water. In the method of the present invention, the reducing agent to be added to the endocrine disrupting substance-containing water is not particularly limited, for example,
Hydrogen, hydrazine, hydroxylamine, ammonia,
Methanol and the like can be mentioned. By reductive decomposition, among endocrine disrupting substances, organochlorine compounds can be dechlorinated and removed. For reductive decomposition, platinum, palladium, ruthenium, rhodium, iron, copper,
It is preferable to use a catalyst such as iridium or nickel. The amount of the reducing agent added for reductive decomposition of the endocrine disrupting substance is not particularly limited, but is 1 to 2 times the stoichiometric amount required to completely reduce or decompose the adsorbed endocrine disrupting substance. It is preferred that In the method of the present invention, water can be passed through a hydrophobic membrane having a catalytic function under ultraviolet irradiation, with or without the addition of an oxidizing agent to water containing endocrine disrupting substances. When an oxidizing agent is added, the type and amount of the oxidizing agent to be added may be the same as in the case where oxidative decomposition is performed without irradiation with ultraviolet light. There is no particular limitation on the source of ultraviolet light to be irradiated, and examples thereof include a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, a xenon lamp, a deuterium lamp, and a metal halide lamp.
By irradiating with ultraviolet rays, the oxidative decomposition reaction can be promoted, and by photolysis, endocrine disrupting substances other than inorganic substances such as cadmium and lead can be oxidized and removed in general. At the time of photodecomposition, it is preferable to use a photocatalyst such as titania or zirconia, which has a decomposing activity upon receiving ultraviolet rays.

[0008] In carrying out the method of the present invention, prior to the passage of the water containing endocrine disrupting substance through the hydrophobic membrane having a catalytic function, the suspended substance in the water containing endocrine disrupting substance is subjected to coagulation sedimentation and filtration. Removal is preferred. Preliminary removal of suspended substances prevents contamination of the hydrophobic membrane, enabling long-term treatment, improving the quality of the permeated water that is treated water, and wastefully using the oxidizing agent to be added. Can be prevented. FIG. 1 is a process flow chart of an embodiment of the method of the present invention. An oxidizing agent is added to the raw water from which suspended substances have been removed by the pretreatment, and the raw water is sent to the filtration membrane device 1 provided with a hydrophobic membrane having a catalytic function. In the permeated water that has passed through the hydrophobic membrane, endocrine disrupting substances are decomposed and removed. The concentrated water of the filtration membrane device is returned to the supply water pipe of the filtration membrane device, and is again sent to the filtration device for processing. FIG. 2 is a process flow chart of another embodiment of the method of the present invention. Raw water from which suspended substances have been removed by pretreatment,
It is sent to the filtration membrane device 1 in which the ultraviolet lamp 2 is installed on the inflow water side. In the permeated water that has passed through the hydrophobic membrane, endocrine disrupting substances are decomposed and removed. The concentrated water of the filtration membrane device is
The water is returned to the supply water pipe of the filtration membrane device, and is sent again to the filtration device for processing. The reason why the endocrine disrupting substance is effectively decomposed and removed by the method of the present invention is not clear, but is presumed to be due to the following mechanism. That is,
Since many endocrine disrupting substances are hydrophobic, when endocrine disrupting substance-containing water is passed through a hydrophobic membrane, hydrophilic substances in the water pass through the membrane quickly, but endocrine disrupting substances do not. It passes slowly while repeating adsorption and desorption to the surface of the hydrophobic membrane and the pore wall. To this end, the endocrine disrupting substance is decomposed and removed by the action of the oxidation-reduction catalyst supported on the hydrophobic membrane and reacting with the added oxidizing or reducing agent. Since the hydrophilic substance contained in the water passes through the hydrophobic membrane quickly, the amount of the oxidizing agent or the reducing agent consumed for the decomposition of the hydrophilic substance is small, and the wasteful consumption of the oxidizing agent or the reducing agent is suppressed. As a result, low-concentration endocrine disrupting substances contained in water can be efficiently decomposed and removed. When the membrane having the catalytic function is a hydrophilic membrane, the hydrophilic substance in water is decomposed more preferentially, so that the rate of decomposing and removing endocrine disrupting substances is reduced.

[0009]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. Example 1 A polytetrafluoroethylene microfiltration membrane having a pore size of 0.1 μm was immersed in a 0.1% by weight methyl alcohol solution of a tetrafluoroethylene / vinyl alcohol copolymer.
After immersion, the film was dried at 110 ° C. to make a part of the film surface hydrophilic. The hydrophilized portion was about 20% of the entire membrane surface. This film was immersed in an aqueous solution of nickel sulfate and evaporated to dryness, so that nickel was 1% by weight of the film.
It was carried so that it might become. Next, this was immersed in an aqueous solution of sodium hypochlorite and sodium hydroxide to perform an activation treatment, thereby obtaining a polytetrafluoroethylene microfiltration membrane supporting nickel peroxide. Using this filtration membrane, membrane area 2
A 0 cm ² filter was made. Nonylphenol was added to 10 liters of river surface water so as to have a concentration of 40 μg / liter to prepare test water, and nonylphenol was subjected to a decomposition treatment using the above-described filtration device according to the process shown in FIG. Ozone was dissolved in the test water so that the concentration became 1 mg / liter, and a filtration volume rate of 10 ml / cm was added to the filtration device.
Water was passed for ² hours. After 24 hours, the concentration of nonylphenol was measured by solid phase extraction-GC / MS method. As a result, the permeated water was 0.1 μg / liter or less and the concentrated water was 4 μg / liter. Example 2 Instead of a polytetrafluoroethylene microfiltration membrane (pore diameter: 0.1 μm) carrying nickel peroxide, the membrane was immersed in an aqueous solution of palladium chloride, and palladium was carried on the membrane so as to be 1% by weight of palladium. Except for using a tetrafluoroethylene microfiltration membrane (pore size 0.1 μm),
The same operation as in Example 1 was repeated. After 24 hours, the concentration of nonylphenol in the membrane permeated water was 0.1 μg / liter or less, and the concentration of the concentrated water was 4 μg / liter. Example 3 River surface water 10 was installed in a filtration membrane device equipped with a palladium-supported polytetrafluoroethylene filtration membrane used in Example 2.
2,4-dichlorophenol at a concentration of 40 μg per liter
/ L was dissolved in test water added so that the concentration became 1 mg / L, and the solution was passed at 80 ° C. Twenty-four hours later, the concentration of 2,4-dichlorophenol was 0.1 μg / liter or less for permeated water and 5 μg / liter for concentrated water. Example 4 After a mixed solution of titanium isopropoxide and isopropanol was stirred at 5 ° C. for 2 hours, the molar ratio was adjusted to be titanium isopropoxide: isopropanol: ultra pure water = 1: 10: 4 for 4 hours. The hydrolysis reaction was performed. After the reaction, the mixture was suction-filtered and dried at 100 ° C. under aeration to obtain amorphous titanium oxide fine particles. Hydrogen peroxide solution was added to the amorphous titanium oxide fine particles and stirred for 2 hours to obtain a titanium oxide sol. Hydrogen peroxide solution was further added to this sol and stirred for 30 minutes to obtain a titanium oxide coating solution.
The polytetrafluoroethylene microfiltration membrane partially hydrophilized obtained in the same manner as in Example 1 was immersed in the above-mentioned titanium oxide coating solution, and calcined at 250 ° C. to obtain polytetrafluoroethylene supported on titanium oxide. Using an ethylene microfiltration membrane, a filtration membrane device shown in FIG. 2 was produced. A low-pressure mercury ultraviolet lamp of 10 kW in total was provided on the inflow water side of the filtration membrane device to perform ultraviolet irradiation. The test water used in Example 1 was passed through the filter membrane device at the same speed as in Example 1 without adding ozone. After 24 hours, the concentration of nonylphenol was 0.1 μg / liter or less for permeated water and 7 μg / liter for concentrated water. Comparative Example 1 Instead of the polytetrafluoroethylene microfiltration membrane in which part of the membrane surface used in Example 1 was made hydrophilic, a pore size of 0.1 was used.
The same operation as in Example 1 was repeated, except that a hydrophilic ceramic microfiltration membrane carrying nickel peroxide obtained by immersing a μm ceramic microfiltration membrane in an aqueous nickel sulfate solution was used. After 24 hours, the concentration of nonylphenol was 4 μg / liter for permeated water and 1 μg / liter for concentrated water. Table 1 shows the results of Examples 1 to 4 and Comparative Example 1.

[0010]

[Table 1]

As can be seen from Table 1, ozone was added to test water containing nonylphenol, and water was passed through a hydrophobic polytetrafluoroethylene membrane carrying nickel peroxide. Example 2, in which ozone was added to test water to be tested and water was passed through a polytetrafluoroethylene membrane carrying palladium, hydrogen gas was added to test water containing 2,2,4-dichlorophenol, and polytetrafluoroethylene supported on palladium was added. In Example 3 in which water was passed through the membrane, and in Example 4 in which test water containing nonylphenol was passed through the titanium oxide-supported polytetrafluoroethylene membrane under ultraviolet irradiation, the nonylphenol concentration in the membrane permeated water or 2,4-dichloromethane was measured. The phenol concentration was 0.1 μg / liter or less in all cases, and nonylphenol or 2,4-dichloro Phenol is almost completely removed. On the other hand, even in the case where the concentrations of nonylphenol and ozone were the same as those in Example 1, in Comparative Example 1 in which water passed through the hydrophilic ceramic membrane supporting nickel peroxide, the nonylphenol concentration of the membrane permeated water was 4 μg. Per liter, which indicates that nonylphenol is insufficiently decomposed by the hydrophilic film compared to the hydrophobic film.

[0012]

According to the method of the present invention, an endocrine disrupting substance contained in a trace amount in water can be selectively decomposed and removed, thereby making it harmless at low cost.

[Brief description of the drawings]

FIG. 1 is a process flow chart of an embodiment of the method of the present invention.

FIG. 2 is a process flow chart of another embodiment of the method of the present invention.

[Explanation of symbols]

 1 Filtration membrane device 2 UV lamp

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) C02F 1/70 C02F 1/70 1/72 1/72 101 101 (72) Inventor Yuichi Muramatsu Shinjuku-ku, Tokyo 3-7 Nishi Shinjuku Kurita Kogyo Co., Ltd. (72) Inventor Naoki Matsukei 3-4-7 Nishi Shinjuku Nishi Shinjuku, Shinjuku-ku, Tokyo F-term inside Kurita Kogyo Co., Ltd. KB30 KD01 KD02 KD21 KD22 KD23 KD28 KD30 KE05P KE11Q KE12P KE13P KE14P MA01 MA03 MA22 MB10 MB11 MC22 MC23 MC29 MC30X MC33X MC46 MC65 MC90 NA54 NA60 NA63 PA01 PB04 PB70 4D038 AA02 AB08 BB13 AB11 AB18 AB09 AB13 AB15 AB19 BA08 BA09 BA14 BA20 BB01 BB02 BB05 BB13 BC06 BC07 BC09 BD02 BD08 CA09 CA13 CA15 CA16

Claims (6)

[Claims] 1. A method for treating endocrine disrupting substance-containing water, which comprises passing the endocrine disrupting substance-containing water through a hydrophobic membrane having a catalytic function. 2. The method for treating endocrine disrupting substance-containing water according to claim 1, wherein an oxidizing agent is added to the endocrine disrupting substance-containing water and the water is passed through a hydrophobic membrane having a catalytic function. 3. The method for treating endocrine disrupting substance-containing water according to claim 2, wherein an oxidizing agent is added to the endocrine disrupting substance-containing water and water is passed through a hydrophobic membrane having a catalytic function under irradiation with ultraviolet rays. 4. The method for treating water containing endocrine disrupting substance according to claim 1, wherein the water containing endocrine disrupting substance is passed through a hydrophobic membrane having a catalytic function under ultraviolet irradiation. 5. The method for treating endocrine disrupting substance-containing water according to claim 1, wherein a reducing agent is added to the endocrine disrupting substance-containing water and the water is passed through a hydrophobic membrane having a catalytic function. 6. The water containing an endocrine disrupting substance according to claim 1, wherein the hydrophobic membrane having a catalytic function is obtained by carrying a metal or metal oxide catalyst on a hydrophobic membrane having a hydrophilic surface. Processing method.