Antibacterial treatment device

Abstract

To provide an antibacterial treatment device capable of reducing elution of components into a solution and ensuring long-lasting antibacterial effect.SOLUTION: An antibacterial treatment device 10 comprises: antibacterial carrier particles 2 composed of a composite oxide ceramic containing a rare-earth element and at least one element selected from molybdenum, tungsten, and vanadium, the antibacterial carrier particles having a particle diameter of 50 to 1000 μm as measured by the sieving method defined in JIS-Z8815 (1994); and a container 4 that holds the antibacterial carrier particles and brings a liquid to be treated into contact with the antibacterial carrier particles when the liquid flows into and out of the inside.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an antibacterial treatment device using antibacterial composite oxide ceramics. [Background technology]

[0002] Known antibacterial and antiviral materials include metals such as Ag (silver) and Cu (copper), and photocatalysts such as titanium oxide and titanium apatite, many of which have been put to practical use. However, photocatalysts have the problem that they do not exhibit antibacterial and antiviral activity in environments without light irradiation. On the other hand, Ag and Cu are active even in the dark, but have the problems of short lifespan and high cost.

[0003] In addition, many metal oxides, such as titanium oxide, have a high proportion of ionic bonds, and their surfaces are usually covered with oxygen atoms, which are larger than cations. In the atmosphere, the H + combines with surface oxygen to form hydroxyl groups, and dissociated OH - is coordinated to the metal and covered with hydroxyl groups, and the presence of several or more molecules of physically adsorbed water on top of it generally makes it hydrophilic. Metal oxides have been surface-treated with organic substances to make them water-repellent, but this has the problem of low durability, so there is a demand for materials with excellent durability and water-repellency.

[0004] Therefore, composite oxide ceramics that have both water-repellent properties and antibacterial and antiviral properties have been developed (Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. W202O / 017493 Summary of the Invention [Problem to be solved by the invention]

[0006] However, there is a demand for a technology that can quickly kill bacteria present in a solution, such as a circulating bathtub. As a method for removing bacteria from a solution, a powder or chemical of an antibacterial agent is generally added to the solution. However, adding an antibacterial agent or drug means that the antibacterial agent must be immersed in the solution for a long period of time, which may change the properties of the solution itself or cause components derived from the antibacterial agent or drug to leach out, potentially having a negative impact on the environment. Furthermore, in such an addition method, if the antibacterial effect is high immediately after addition but the effect does not last long, it becomes necessary to add antibacterial agents or chemicals from time to time to maintain the antibacterial effect for a long period of time, which increases running costs. For these reasons, there is a demand for an antibacterial treatment device that can suppress the elution of components into the solution and maintain the antibacterial effect for a long period of time.

[0007] Therefore, an object of the present invention is to provide an antibacterial treatment device that suppresses the elution of components into a solution and maintains the antibacterial effect for a long period of time. [Means for solving the problem]

[0008] In order to solve the above problems, the antibacterial treatment device of the first aspect of the present invention comprises antibacterial carrier particles made of a composite oxide ceramic containing a rare earth element and at least one element selected from molybdenum, tungsten, and vanadium, and having a particle size of 50 to 1000 μm as determined by the sieving method specified in JIS-Z8815 (1994), and a container that holds the antibacterial carrier particles and brings the treated liquid into contact with the antibacterial carrier particles as it passes through and leaves the container.

[0009] According to the antibacterial treatment device of the first aspect, the particle size of the antibacterial carrier particles is set to 50 to 1000 μm, so that the antibacterial effect lasts for a long time, water permeability is improved, and the amount of particles used can be reduced.

[0010] The second aspect of the antibacterial treatment device of the present invention is an antibacterial treatment device comprising an antibacterial carrier made of a composite oxide ceramic containing a rare earth element and at least one element selected from molybdenum, tungsten, and vanadium, and having a plurality of pores communicating in one direction, wherein the circle equivalent diameter of the pores is 10 to 200 μm, and the liquid to be treated comes into contact with the antibacterial carrier when passing through the pores.

[0011] According to the antibacterial treatment device of the second aspect, the equivalent circle diameter of the pores is set to 10 to 200 μm, so that the antibacterial effect lasts for a long time, water permeability is improved, and the amount of particles used can be reduced. Here, since it is known that the radius ratio of the gaps formed between particles is approximately 1 / 5 of the particle radius ratio, the circle equivalent diameter of pore 12h, 10 to 200 μm, corresponds to the particle diameter of the antibacterial carrier particles in the first embodiment of the antibacterial treatment device, 50 to 1000 μm.

[0012] In the antibacterial treatment device of the present invention, the rare earth element may be at least one selected from La, Ce, and Gd.

[0013] In the antibacterial treatment device of the present invention, the composite oxide ceramics (La 2-x Ce x )(Mo 2-y W y )O9 (where x=0 to 2, y=0 to 2).

[0014] In the antibacterial treatment device of the present invention, the composite oxide ceramics is La2(Mo 2-y W y )O9 (where y=0 to 2). In the antibacterial treatment device of the present invention, the composite oxide ceramic may be represented by La2Mo2O9. In the antibacterial treatment device of the present invention, the composite oxide ceramic may be represented by La2MoWO9. [Effects of the Invention]

[0015] According to the present invention, an antibacterial treatment device can be obtained that suppresses the elution of components into a solution and maintains antibacterial effects for a long period of time. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a cross-sectional view of an antibacterial treatment device according to an embodiment of a first aspect of the present invention. [Figure 2] FIG. 1 is a flowchart showing an example of manufacturing a composite oxide ceramic by a complex polymerization method. [Figure 3] FIG. 1 is a flowchart showing an example of manufacturing a composite oxide ceramic by a precipitation method. [Figure 4] FIG. 2 is a cross-sectional view of an antibacterial treatment device according to an embodiment of the second aspect of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present invention will be described. FIG. 1 is a cross-sectional view along the axial direction of an antibacterial treatment device 10 according to a first embodiment of the present invention. The antibacterial treatment device 10 includes antibacterial carrier particles 2 and a container 4 that holds the antibacterial carrier particles 2 and stores the liquid S to be treated. The antibacterial carrier particles 2 are made of composite oxide ceramics, which will be described later, and have a particle size of 50 to 1000 μm. The particle size is determined by the sieving method (particle size measurement) specified in JIS-Z8815 (1994).

[0018] The vessel 4 is a cylindrical column with a bottom, its axis running vertically, its top open to form an inlet 4a for the liquid S to be treated, and its bottom narrowing to form an outlet 4b for the treated liquid Sp to flow downward. A filter 6 is disposed upstream of the outlet 4b to retain the antibacterial carrier particles 2 and prevent them from being discharged from the outlet 4b. When the liquid to be treated S enters and leaves the inside of the container 4, it comes into contact with the antibacterial carrier particles 2, and antibacterial treatment is carried out. In the present invention, "antibacterial" is not limited to reducing or killing bacteria, but also includes "antiviral."

[0019] The composite oxide ceramics that become the antibacterial carrier particles 2 contain a rare earth element and at least one element selected from molybdenum, tungsten, and vanadium. The composite oxide ceramics that can be used are substantially the composite oxide ceramics described in the above-mentioned Patent Document 1 (International Publication No. W2020 / 017493). The composite oxide ceramic contains at least the above elements, and usually further contains oxygen atoms, and may further contain other elements as long as the effects are not impaired. Each component of such composite oxide ceramic will be described below.

[0020] The composite oxide ceramic of this embodiment contains a rare earth element. The rare earth element is usually contained as an oxide. In this embodiment, the rare earth element is a collective term for Sc (scandium), Y (yttrium), and lanthanoids (elements with atomic numbers 57 to 71), and these elements can be used alone or in combination of two or more. In this embodiment, from the viewpoint of water repellency, it is preferable that the rare earth element contains a lanthanoid, and it is more preferable that the rare earth element contains at least one selected from La (lanthanum), Ce (cerium), and Gd (gadolinium). Furthermore, from the viewpoint of antibacterial and antiviral properties, it is preferable to contain La and Ce as rare earth elements, and it is particularly preferable to contain La. The combination of La and Mo provides excellent antibacterial and antiviral properties.

[0021] The composite oxide ceramic of this embodiment also contains at least one element selected from Mo (molybdenum), W (tungsten), and V (vanadium), which are usually contained as oxides. The composite oxide ceramic of this embodiment has antibacterial and antiviral properties due to the inclusion of at least one selected from molybdates, tungstates, and vanadates.

[0022] In this embodiment, the content ratio of the rare earth element (element A) to at least one element selected from Mo, W, and V (element B) is not particularly limited, and may be adjusted appropriately depending on the application. In order to achieve both water repellency and antibacterial and antiviral properties, the molar ratio of element A to element B is preferably in the range of 1:9 to 9:1, more preferably 3:7 to 7:3, and particularly preferably 1:1.

[0023] A preferred embodiment of the composite oxide ceramic is (La 2-x Ce x )(Mo 2-y W y )O9, where x=0-2 and y=0-2. A further preferred embodiment of the composite oxide ceramic is La2(Mo 2-y W y )O9, where y=0-2. For example, the composite oxide ceramic of this embodiment may be La2Mo2O9, La2W2O9, La2(Mo 0.5 W 1.5 )O9, La2MoWO9, La2(Mo 1.5 W 0.5 )O9, La 1.8 Ce 0.2 It has a chemical composition such as Mo2O9.

[0024] The composite oxide ceramic of this embodiment may further contain other elements as long as the effects are not impaired. Examples of other elements include transition metal elements. The transition metal elements may be contained as oxides or in other forms without forming oxides. In this embodiment, the content of the other elements is preferably 20 mass % or less, more preferably 10 mass % or less, and even more preferably 5 mass % or less, based on the total amount of the composite oxide ceramic containing the other elements.

[0025] The composite oxide ceramic of this embodiment may be crystalline, such as a single crystal or polycrystal, or amorphous, such as glassy, ​​or may be a combination of crystalline and amorphous parts. The crystalline phase may be a single phase, or a combination of two or more different phases.

[0026] The method for producing the composite oxide ceramic of this embodiment is not particularly limited, and the composite oxide ceramic can be obtained by forming a composite oxide containing a rare earth element and at least one element selected from molybdenum, tungsten, and vanadium, and firing the composite oxide. Suitable production methods include the complex polymerization method and precipitation method described below, but the solid-state reaction method and other production methods described below may also be used. The complex polymerization method, precipitation method, and solid-state reaction method are described below.

[0027] <Complex polymerization> The complex polymerization method will be described with reference to Fig. 2. Fig. 2 is a flowchart showing an example of the complex polymerization method. In the following, as an example, a case where molybdenum is used as at least one element selected from molybdenum, tungsten, and vanadium will be described.

[0028] The complex polymerization method of the present embodiment includes a gelation step (S1) of adding an oxycarboxylic acid and a glycol to an aqueous solution containing a rare earth-containing compound and a molybdenum-containing compound, and then heating the solution to cause an ester reaction between the oxycarboxylic acid and the glycol to form a gel; a drying step (S2) of drying the gel obtained in the gelling step; A calcination step (S3) of calcining the powder obtained by drying the gel; a molding step (S4) of molding the powder after the calcination; and a firing step (S5) of firing the molded body after the molding. The complex polymerization method has the advantage that it is possible to obtain a composite oxide ceramic with excellent uniformity and high density at a relatively low temperature.

[0029] In the gelation step (S1), water is first added to a water-soluble rare earth-containing compound and a molybdenum-containing compound, and the resulting mixture is mixed to form an aqueous solution (S11). Next, an oxycarboxylic acid is added to the aqueous solution to form a metal-oxycarboxylic acid complex (S12). Glycol is then added (S13), and the oxycarboxylic acid and glycol undergo an esterification reaction to form a gel (S14).

[0030] Examples of rare earth-containing compounds that are soluble in water include rare earth nitrates. Examples of molybdenum-containing compounds that are soluble in water include ammonium molybdate. For example, lanthanum nitrate hexahydrate (La(NO3)3·6H2O) is used as the rare earth-containing compound, and ammonium molybdate tetrahydrate ((NH4)6Mo7O) is used as the molybdenum-containing compound. 24 4H2O) can be used.

[0031] Examples of the hydroxycarboxylic acid include citric acid, and examples of the glycol include ethylene glycol and propylene glycol.

[0032] The obtained gel is thoroughly dried in a drying step (S2). The drying method is not particularly limited, but heat drying is preferred. Next, the powder obtained by drying the gel is calcined (calcination step: S3). Although not particularly limited, calcination is preferably carried out at 500°C or higher. The atmosphere in which calcination is carried out is not particularly limited, and it can be carried out in air, for example. The obtained powder may be partially sintered, so it may be pulverized to a fine powder if necessary. Although not particularly limited, dry pulverization is preferred. The type of pulverizer is not particularly limited, and can be appropriately selected from known types.

[0033] Next, the obtained calcined powder (calcined powder) is molded into a desired shape (molding step: S4). The molding method is not particularly limited, and can be appropriately selected from known molding methods such as uniaxial pressing. Next, the resulting molded body is fired to obtain a sintered body of the composite oxide ceramic (firing step: S5). The firing method is not particularly limited, but a suitable example is a method in which the molded body is heated in the atmosphere at about 900°C.

[0034] <Sedimentation method> Next, a precipitation method will be described as another method for producing composite oxide ceramics. Fig. 3 is a flowchart showing an example of the precipitation method. In the following, as an example, a case where molybdenum is used as at least one element selected from molybdenum, tungsten, and vanadium will be described.

[0035] The precipitation method in this embodiment includes a step (S21) of stirring and mixing aqueous solutions containing a rare earth-containing compound and a molybdenum-containing compound, and then heating the mixture to react with each other to obtain an intermediate substance (S22); a drying step (S23) of drying the obtained intermediate material; A calcination step (S24) of calcining the powder obtained by the drying; a molding step (S25) of molding the powder after the calcination; and a firing step (S26) of firing the molded body after the molding. The precipitation method has the advantage that it is possible to obtain a composite oxide ceramic with excellent uniformity and high density at a relatively low temperature.

[0036] Specifically, a water-soluble rare earth-containing compound is first dissolved in distilled water to prepare a rare earth-containing aqueous solution. A water-soluble molybdenum-containing compound is then dissolved in distilled water to prepare a molybdenum-containing aqueous solution. These aqueous solutions are then mixed and stirred at room temperature (S21). The mixed aqueous solution is then heated for a predetermined time (S22) to obtain an intermediate substance.

[0037] Examples of rare earth-containing compounds that are soluble in water include rare earth nitrates. Examples of molybdenum-containing compounds that are soluble in water include ammonium molybdate. For example, lanthanum nitrate hexahydrate (La(NO3)3·6H2O) is used as the rare earth-containing compound, and ammonium molybdate tetrahydrate ((NH4)6Mo7O) is used as the molybdenum-containing compound. 24 4H2O) can be used.

[0038] The obtained intermediate substance is thoroughly dried in a drying step (S23). The drying method is not particularly limited, but heat drying is preferred. Next, the dried intermediate substance (powder) is calcined to obtain a calcined powder (calcination step: S24). Although not particularly limited, calcination is preferably carried out at 500°C or higher. The atmosphere in which the calcination is carried out is not particularly limited, and the calcination can be carried out, for example, in air.

[0039] The obtained powder may be partially sintered, so it may be pulverized to a fine powder as needed. The pulverization method is not particularly limited, but dry pulverization is preferred. The type of pulverizer is not particularly limited, and can be appropriately selected from known types. Next, the obtained calcined powder (calcined powder) is molded into a desired shape (molding step: S25). The molding method is not particularly limited, and can be appropriately selected from known molding methods such as uniaxial pressing.

[0040] Next, the resulting molded body is fired to obtain a sintered body of the composite oxide ceramic (firing step: S26). The firing method is not particularly limited, but a suitable example is a method in which the molded body is heated in air at about 900°C.

[0041] <Solid-state reaction method> Next, we will explain the solid-state reaction method, another method for manufacturing composite oxide ceramics. The solid-state reaction method involves mixing powder of a rare-earth-containing compound as raw materials with powder of molybdenum oxide (MoO3) and calcining the mixture to obtain a calcined powder. The raw material rare-earth-containing compound can be a rare-earth oxide such as lanthanum oxide (La2O3). The rare earth-containing compound and molybdenum oxide are mixed in a ball mill for 24 hours, and then calcined at, for example, 900°C or higher to obtain the desired single-phase composite oxide ceramic powder. The atmosphere for calcining and firing can be the same as that for the complex polymerization method. The molding method can also be the same as that for the complex polymerization method, and therefore a description thereof will be omitted here.

[0042] Next, in the firing step, the obtained molded body is fired to obtain a sintered body of the composite oxide ceramic. The firing method is not particularly limited, but a suitable example is a method in which the compact is heated in air at about 1200°C.

[0043] The antibacterial carrier particles 2 are produced using such composite oxide ceramics. For example, the sintered body sintered by the above-mentioned manufacturing method can be pulverized and classified to obtain powdery (granular) antibacterial carrier particles 2 having a particle size of 50 to 1000 μm.

[0044] Antibacterial carrier particles 2 exert their antibacterial effect by physically coming into contact with bacteria, deactivating them. This is thought to be because the rare earth elements on the surface of antibacterial carrier particles 2 adsorb and inactivate negatively charged bacteria (Nakamura Kiminori et al., Journal of Intestinal Microbiology (2019)). If the particle size of the antibacterial carrier particles 2 is less than 50 μm, the surface area in contact with bacteria increases, but water permeability decreases and the amount of antibacterial carrier particles 2 used increases, resulting in increased costs. If the particle size of the antibacterial carrier particles 2 exceeds 1000 μm, the surface area in contact with bacteria will be small, and the antibacterial effect will be reduced. Furthermore, the composite oxide ceramics that make up the antibacterial carrier particles 2 have a low ion leakage rate.

[0045] As an index of water permeability, the flow rate is preferably 0.01 to 10 mL / min, more preferably 0.1 mL / min or more, and most preferably 1 mL / min or more.

[0046] Thus, according to the antibacterial treatment device 10 relating to the first aspect of the present invention, antibacterial treatment is performed using antibacterial carrier particles 2 made of composite oxide ceramics with low ion leakage, thereby suppressing the leaching of components into the solution. By setting the particle diameter of the antibacterial carrier particles 2 to 50 to 1000 μm, the antibacterial effect lasts for a long time, water permeability is improved, and the amount used can be reduced.

[0047] Next, an antibacterial treatment device 20 according to an embodiment of the second aspect of the present invention will be described. FIG. 4 is a cross-sectional view of the antibacterial treatment device 20 taken along the axial direction. The antibacterial treatment device 20 includes an antibacterial carrier 12. In this example, the antibacterial treatment device 20 is installed in the piping of a circulating bathtub and further includes a storage section 14 that stores the antibacterial carrier 12, and a catcher 16 that is attached upstream of the storage section 14 and captures foreign matter such as hair.

[0048] The antibacterial carrier 12 is made of a composite oxide ceramic containing a rare earth element and at least one element selected from molybdenum, tungsten, and vanadium, and has a plurality of pores 12h that communicate with each other in one direction. The composite oxide ceramic is the same as that described in the first embodiment, so a description thereof will be omitted. In this example, the antibacterial carrier 12 is cylindrical, and has pores 12h that communicate with each other along its axial direction.

[0049] The upstream side of the storage unit 14 is connected to a pipe to form an inlet 14a for the liquid S to be treated in the bath, and the downstream side is connected to a pipe to form an outlet 14b for returning the treated liquid Sp to the bath. The liquid to be treated S flows along the axial direction of the antibacterial carrier 12, and when passing through the pores 12h, it comes into contact with the antibacterial carrier 12 (composite oxide ceramics) on the inner walls of the pores 12h, thereby undergoing antibacterial treatment.

[0050] The antibacterial carrier 12 is manufactured using the composite oxide ceramics described above. For example, the calcined powder before sintering in the above-mentioned manufacturing method can be combined with a known binder resin, a solvent, etc. to form a paste, which forms an antibacterial carrier precursor having pores, and then sintered to produce the antibacterial carrier 12. Alternatively, a cylindrical body having pores may be prepared from a ceramic such as alumina or a metal, and the cylindrical body may be dipped in a slurry containing the calcined powder and a solvent to support the slurry on the inner walls of the pores, followed by firing the entire body, thereby forming a composite oxide ceramic film supported on the inner walls of the pores.

[0051] Here, the equivalent circle diameter of the pores 12h is 10 to 200 μm. In the embodiment of the first aspect described above, if the particle diameter of the antibacterial carrier particles 2 is 50 to 1000 μm, the antibacterial effect can be maintained for a long period of time and water permeability can be improved. Therefore, in order to realize the effect of such a particle size regulation of the antibacterial carrier particles 2 in the antibacterial carrier 12, the circle equivalent diameter of the pores 12h is set to 10 to 200 μm.

[0052] The relationship between the particle size of the antibacterial carrier particle 2 and the circle equivalent diameter of the pore 12h of the antibacterial carrier 12 was based on the literature (Mori Tomohiro et al., "Study on a method for calculating the pore size distribution formed between soil particles under close packing," Geotechnical Journal Vol. 14, No. 2, pp. 197-204, 2019). Specifically, based on the statement in the same document that "the gap radius ratio (formed between particles) is 22.5% of the soil particle radius ratio" (page 200, right column, lines 2-3), the circle equivalent diameter of pore 12h was considered to be 1 / 5 (≒22.5%) of the particle diameter of antibacterial carrier particle 2. The circle-equivalent diameter of the pores 12h is calculated by taking a microscope image of an end face or cross section perpendicular to the axial direction of the antibacterial carrier 12. Then, for 10 or more pores 12h in the obtained microscope image, the circle-equivalent diameters are measured using image analysis software (ImageJ) and the average value is calculated.

[0053] As a result, the particle diameter of the antibacterial carrier particles 2, 50 to 1000 μm, corresponds to the circular equivalent diameter of the pores 12h, 10 to 200 μm, and the antibacterial effect of the antibacterial carrier 12 also lasts for a long time and improves water permeability, similar to the first aspect of the embodiment.

[0054] In this way, in the antibacterial treatment device 20 according to the second embodiment, antibacterial treatment is performed using antibacterial carrier particles 2 made of water-insoluble composite oxide ceramics, so that components do not dissolve into the solution and the antibacterial effect lasts for a long time.

[0055] It goes without saying that the present invention is not limited to the above-described embodiments, but covers various modifications and equivalents that fall within the spirit and scope of the present invention. The shapes of the antibacterial carrier 12 and the pores 12h are not limited. [Example]

[0056] Using a column-shaped antibacterial treatment device 10 shown in Figure 1, a predetermined amount of LMWO (La2Mo2O9 and La2MoWO9) with various particle sizes as shown in Table 1 was packed as antibacterial carrier particles 2. The particle sizes were determined by the sieving method specified in IS-Z8815 (1994). Test bacteria solution (Escherichia coli) was dissolved in 1 / 500 NB solution (medium) and 5.0 x 10 5 The bacterial solution (prepared to approximately CFU / mL) was passed through the tube in one pass (approximately 5 seconds), and the bacterial solution after treatment was collected.

[0057] After 24 hours, the antibacterial activity was evaluated as follows: After treatment, 0.4 mL of the bacterial solution (number of colonies = 2.0 × 10 5 CFU equivalent) were collected and placed in 10 mL of SCDLP (soybean casein digest broth with lecithin and polysorbate) medium. Next, the SCDLP medium containing the bacteria was diluted with phosphate buffered saline (PBS) to prepare a bacterial dilution solution. Thereafter, 1 mL of the above bacterial dilution solution was added to and mixed with NA (Nutrient Agar) medium, and cultured at 35°C for 48 hours to form bacterial colonies. Next, the number of colonies on the NA medium was counted, and the value obtained by multiplying the obtained number of colonies by the dilution factor was taken as the number of surviving bacteria (N). As a control, bacteria were seeded on a glass plate and cultured for 24 hours, after which the number of colonies was counted. The colony count was performed three times, and the average value was used. An activity value of 2 or more can be determined to have antibacterial activity.

[0058] The water permeability was evaluated as follows. Pure water was poured into each column containing antibacterial carrier particles 2 with different particle sizes, and the flow rate of the water flowing out of the outlet 4b by natural fall without applying external force was determined. If water flowed within the range of 0.01 to 10 mL / min, it was rated as good (rated ◯), and if the flow rate was 0.01 mL / min or less (or water could not flow), it was rated as unsatisfactory (rated ?). The flow rate was obtained by dividing the actual amount of water flowing by the flow time. The results obtained are shown in Table 1.

[0059] [Table 1]

[0060] As is clear from Table 1, in Examples 1 to 3 in which the particle size of the antibacterial carrier particles 2 measured by the sieving method was 50 to 1000 μm, the particles had antibacterial activity and also had good water permeability. The flow rates when the test bacterial solution was passed through Examples 1 to 3 were 0.1 mL / min, 10 mL / min, and 10 mL / min, respectively.

[0061] On the other hand, in Comparative Example 1, in which the particle size of the antibacterial carrier particles 2 measured by the sieving method exceeded 1000 μm, no antibacterial activity was observed. In the case of Comparative Example 2 in which the particle size of the antibacterial carrier particles 2 measured by the sieving method was less than 50 μm, the test bacteria solution did not flow out of the column, and the water permeability was poor. No antibacterial activity occurred. In the case of Comparative Example 1, in which Zr beads having a particle size of 300 μm were used as the carrier particles 2 instead of La 2 Mo 2 O 9 , no antibacterial activity was observed. In the case of Comparative Example 1, in which a PTFE type membrane filter (pore diameter: 0.2 μm) was used instead of the column, the liquid could not pass through, and the water permeability was poor. [Explanation of symbols]

[0062] 2. Antibacterial carrier particles 4 containers 12 Antibacterial carriers 12h pores 10, 20 Antibacterial treatment device

Claims

1. antibacterial carrier particles made of composite oxide ceramics containing a rare earth element and at least one element selected from molybdenum, tungsten, and vanadium, the particles having a particle size of 50 to 1000 μm as determined by a sieving method specified in JIS-Z8815 (1994); a container for holding the antibacterial carrier particles and allowing the liquid to be treated to come into contact with the antibacterial carrier particles when the liquid enters or leaves the container; An antibacterial treatment device comprising:

2. An antibacterial treatment device comprising an antibacterial carrier made of composite oxide ceramics containing a rare earth element and at least one element selected from molybdenum, tungsten, and vanadium, the antibacterial carrier having a plurality of pores communicating in one direction, The pores have an equivalent circle diameter of 10 to 200 μm, An antibacterial treatment device in which the liquid to be treated comes into contact with the antibacterial carrier when passing through the pores.

3. The antibacterial treatment device according to claim 1 or 2, wherein the rare earth element is at least one selected from the group consisting of La, Ce, and Gd.

4. The composite oxide ceramics (La ２－ｘ Ce ｘ ) (Mo ２－ｙ W ｙ ) O ９ The antibacterial treatment device according to claim 1 or 2, wherein x is 0 to 2, y is 0 to 2, and the antibacterial treatment device according to claim 2, wherein x is 0 to 2, and y is 0 to 2.

5. The composite oxide ceramic is La ２ (Mo ２－ｙ W ｙ ) O ９ The antibacterial treatment device according to claim 1 or 2, wherein the antibacterial treatment device is represented by the formula (where y=0 to 2).

6. The composite oxide ceramic is La ２ Mo ２ O ９ The antibacterial treatment device according to claim 4 , wherein

7. The composite oxide ceramic is La ２ MoWO ９ The antibacterial treatment device according to claim 4 , wherein

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