JPH09252770A - Microorganism carrier and biological treatment apparatus using the carrier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a microorganism carrier usable as a water-treatment carrier for the biological decomposition and removal of dissolved substances, a bioreactor, etc., by forming protrusions positively chargeable in water and having the form of a cord, etc., on a material acting as a swingable stem. SOLUTION: A cord having a bending resistance of >=6cm (by 45 deg. cantilever method in conformity to JIS L1085) is produced by planting fibers such as polyester fibers on a core made of e.g. a polyester by electrostatic planting. The cord is cut to about 8cm long, the cut cords are clamped nearly at the center part with a pair of stems 1 and the stems are twisted to fix the cords and obtain a structure having a number of protrusions 2 protruding perpendicular to the stem 1 in nearly radial symmetry. The protrusions 2 of the structure is sufficiently impregnated with an ethanol solution of a quanternarized polymer produced by reacting a random copolymer of 4-vinylpyridine and styrene with benzyl chloride and the solution is dried to obtain the objective microorganism carrier having the protrusions 2 positively chargeable in water and formed on the material 1 acting as an stem.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel microbial carrier. More specifically, the present invention relates to a novel microbial carrier which is preferably used in water treatment for biologically decomposing and removing dissolved substances and in bioreactors for producing specific substances.

[0002]

2. Description of the Related Art Conventionally, there is a biofilm method as a method for purifying contaminated water such as sewage, industrial wastewater, and raw water for tap water. As a microorganism carrier for supporting this microorganism, a honeycomb structure, a corrugated plate, a perforated disk is used. Etc. are known. In addition,
No. 10394 discloses a contact material for a wastewater treatment device in which tufted fibers are radially projected from a core material. Further, JP-A-6-7789 discloses a porous carrier having an anion exchange group on the surface and / or inside. Further, JP-A-6-212544 discloses a microorganism-immobilized carrier having a microorganism-adsorbing polymer attached to the surface of a nonwoven fabric.

However, in a carrier obtained by combining or deforming a sheet having a flat surface such as a honeycomb structure or a corrugated plate, the amount of adhering microorganisms per unit volume occupied by the carrier is small, and even after once adhering, There are problems such as peeling, and improvement in processing efficiency has been demanded. In the case of a porous disc, the amount of microorganisms attached is larger than that of a sheet having a flat surface, but the initial adhesiveness is low and it takes a long time to start up the apparatus. Furthermore, since the water flow is different in the radial direction of the disc and clogging with sludge is likely to occur in the central part where the flow velocity is low and backwash regeneration is difficult, the sludge accumulation on the clogging part reduces the treatment performance. there were.

On the other hand, the carrier described in Japanese Examined Patent Publication No. 7-10394 treats with microorganisms attached to tufts, but the adhesion of microorganisms is low in the initial stage and it takes a long time to start up the apparatus. Since it is necessary and the adhesion force of the microorganism to the carrier is not sufficiently strong, there is a drawback that the biofilm once formed is easily peeled off.

The carrier described in JP-A-6-7789 is a porous carrier having an anion exchange group on the surface and / or inside, but is a carrier in a fluidized bed and has an apparent specific gravity in water. However, the material and form of the carrier are limited because the carrier is required to be close to 1 and capable of withstanding repeated collisions between the carriers or the inner wall of the apparatus. In addition, when the fluid is used, there is a problem that the strainer provided to prevent the carrier from flowing out of the device is likely to be clogged, which makes the operation of the device difficult.

Further, the carrier described in Japanese Patent Laid-Open No. 6-212544 has a simple structure of the carrier, so that an appropriate turbulent flow of the water to be treated does not occur near the surface, and the diffusion efficiency of the substrate, oxygen, etc. It was bad and required a lot of carriers and space to obtain the desired water quality. In addition, by attaching a polymer for adsorbing microorganisms to the surface of the carrier, microorganisms attach in a short period of time and the startup time of the device is shortened,
On the other hand, there is a drawback that the progress of peeling of microorganisms whose activity has been reduced is hindered and, as a result, the processing performance is lowered.

[0007]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made earnest studies on a carrier which does not have the above-mentioned drawbacks, and have arrived at the following invention. An object of the present invention is to provide a microbial carrier that is easy to handle, has a short device startup time, and is excellent in decomposing and removing dissolved substances.

[0008]

Means for Solving the Problems The present invention basically comprises:
The object is achieved by "the microbial carrier characterized in that the shaft material has protrusions that can be positively charged in water."

The material used as the shaft that can be used in the present invention is
From the viewpoint of lightweight and excellent durability, polyamide-based, polyester-based, polyolefin-based, polyvinyl alcohol-based, polyvinyl chloride, known polymer-based materials such as polyvinylidene chloride, and a combination of a plurality of these are preferable, but cotton, Natural fibers and natural materials such as silk, hemp, and wool, and inorganic materials such as carbon and metal may be used. Alternatively, a combination of a plurality of these materials such as wire coated with a polymer material may be used. Further, the shape is preferably a cord shape or a rope shape, and the thickness and the number thereof can be changed depending on the purpose. A polymeric material composed of multifilaments having a total fineness of 1,000 to 20,000 denier, a natural material, or an inorganic material having a total outer diameter of 0.5 to 5 mm is preferable. Further, it is preferable that the shaft can be appropriately swung by water flow or the like.

As the protrusion of the present invention, a structure having a large surface area to which microorganisms adhere is preferable, and a structure having napped fibers or a porous structure is preferable.

The shaft and the projection of the present invention are integrated by sandwiching the projection on the shaft, entanglement of the shaft and the projection, adhesion with an adhesive, heat fusion, and a combination thereof. . The shaft consists of at least two filaments that are difficult to fall off during use. The filaments are twisted independently, and the filaments are twisted together to sandwich the protrusions. A retaining structure is preferred.

In the microbial carrier of the present invention, it is necessary that at least the protrusion has a property of being positively charged in water. Since it suffices to charge in water, it may or may not be charged in air or in a non-aqueous solvent. In addition to the protrusion, other members such as a shaft material may have a property of being positively charged in water. The property of being positively charged in water is that the surface of the protrusion and / or
Alternatively, it is contained inside and is not particularly limited. As a method of imparting the property of being positively charged in water, for example, there is a method of chemically modifying the functional group to have a functional group having the property of being positively charged in water. The functional group having a property of being positively charged in water used in the present invention is preferably a quaternary ammonium group, and substances containing it include vinyl pyridine, dialkylaminoalkyl (meth) acrylamide, dialkylaminoalkyl ( Examples thereof include (meth) acrylate and quaternary products thereof, polyethyleneimine, polyethylenepolyamine, dimethylaminoethyl, allylamine and chitosan. Among these, a molecule containing a quaternized product of vinylpyridine is more preferable because of its high microbial adhesion efficiency. Generally, the surface of microorganisms is negatively charged in water, and it is presumed that the ability of microorganisms to adhere to the surface is manifested by electrical interaction with these positively charged surfaces in water. Further, as a method for allowing the carrier to have a property of being positively charged in water on the surface and / or inside of the carrier, a method of dissolving or dispersing the above substance in a solvent, impregnating or spraying the solution on the carrier, and then drying or polymerizing Or crush the solid consisting of the above substances,
Examples of the method include a method of adhering to the surface of the next carrier and a method of heat-sealing. The method of impregnating with a solution of the above substance is preferable because the property of positively charging in water can be introduced into the surface and inside of the carrier relatively easily. Further, the amount of coating on the carrier varies depending on the form of the protrusions, but if the amount of coating is too large, the adhesion effect does not increase relative to the amount used, and conversely the porous structure of the protrusions suitable for microorganism attachment is destroyed. Therefore, it is preferable that the amount is not more than necessary.

It is preferable that the protrusion of the present invention has a rigidity so that it can be appropriately swung by a water flow or the like, and in particular, when the protrusion is a cord-like member, 45 described in JISL1085.
The measurement by the cantilever method is preferably 4 cm or more, more preferably 6 cm or more, further preferably 8 cm or more. Since the protrusions are positively charged in water, the microorganisms adhere firmly and proliferate, but the protrusions rub against each other appropriately due to water flow, etc., and the excessively attached microorganisms with reduced activity are washed off. As a result, a highly active microorganism can always be attached to the surface of the carrier, and as a result, stable treatment performance can be obtained. Bending degree of 4 cm
In the following case, the adjacent cord-shaped materials are entangled with each other, and the appropriate sludge is not peeled off due to the contact between the cord-shaped materials, and the cord-shaped materials do not serve as a microorganism carrier. Here, the measurement by the cantilever method was performed by gently sliding one cord-like material on a cantilever type testing device.

As the form of the protrusions of the present invention, it is preferable that the protrusions on the same axis and / or the adjacent shafts such as cords, rods, tufts, etc. rub each other uniformly by rocking. Of these, the cord-like material is more preferable.

The cord-like material of the present invention is preferably a structure or a porous structure having a form in which napped fibers are present around a core material.

When a structure having a form in which napped fibers are present around a core material is used as the cord-like material, the core material is a polyamide-based material because it is lightweight and excellent in durability. Known polymer materials such as polyester-based, polyolefin-based, polyvinyl alcohol-based, polyvinyl chloride, polyvinylidene chloride and the like, and a combination of a plurality thereof are preferable, but natural fibers and natural materials such as cotton, silk, hemp, and wool, Alternatively, an inorganic material such as carbon or metal may be used. The form is preferably fibrous or rod-like, and the thickness and the number thereof can be changed depending on the purpose. Polymeric material with total fineness of 200-10,000 denier, natural material, or total outer diameter of 0.5-5 m
m inorganic material and rod-shaped polymer material are preferable. As the material of the napped fiber, carbon fiber, inorganic fiber, activated carbon fiber, natural fiber such as cotton, silk, hemp, and wool, or nylon 6, nylon 66, nylon 12, which is a polymer substance having a fiber-forming ability, Polyamide such as copolymer nylon,
Aromatic polyamide, polyethylene terephthalate, polyester such as copolymerized polybutylene terephthalate, wholly aromatic polyester, polyolefin such as polyethylene and polypropylene, polyurethane, polyacrylonitrile, polyvinyl chloride, polyvinyl alcohol, vinyl polymer, polyvinylidene chloride, polyhydro Sulfite, polyfluorinated ethylene, copolymerized polyfluorinated ethylene,
Examples include polyoxymethylene and the like. Among these, carbon fiber, activated carbon fiber, polyvinyl chloride, and polyvinylidene chloride are more preferable. Composite fibers having a core-sheath structure, a multi-core-sheath structure, a sea-island structure, a bimetal structure, etc., in which a combination of these fiber types or a plurality of polymer substances are combined are also used according to the purpose. The fiber shape may be a straight yarn or a crimped yarn, and the cross-sectional shape may be not only circular but also different-diameter cross-sectional shape. The thickness of the fiber is not particularly limited as it may vary depending on the application, but is 0.01 to 500.
Denier is preferred. Further, the core of the present invention and the fiber to be napped are integrated by sandwiching the fiber into the core, entanglement of the core with the fiber, adhesion with an adhesive, heat fusion, and a combination thereof, or the like. The core itself is a part of the core pulled out in the outer peripheral direction, and the core and the napped fibers may be different in structure or material and may be the same. The napped state of the fiber is a short fiber shape having a free end at the tip, a loop shape, or a combination thereof. Here, the case of a short fiber having a free end at the tip is more preferable because the ability to capture microorganisms at the initial stage of setting the carrier and the self-cleaning property at the time of steady treatment are excellent. Furthermore, the length from the root of the napped fiber to the free end is not particularly limited as it may vary depending on the application and the thickness of the fiber, but it is 0.5-0.5 in consideration of diffusion efficiency of oxygen, substrate and the like. 15 mm is preferable, for example, when the thickness of the fiber is 0.01 to 30 denier, 0.5 to 8 mm is preferable, and 1 to 10 is more preferable.
When the fiber thickness is 4 mm and the fiber thickness is 30 to 500 denier, 3 to 15 mm is preferable, and 3 to 10 is more preferable.
mm. The fiber nap density in the length direction of the core is
Although it may vary depending on the water quality of the water to be treated, the shape and thickness of the fiber, the state of naps, etc., it is preferably in the range of approximately 200 to 200,000 fibers / cm, for example, when the fiber thickness is 0.01 to 30 denier. , 200 to 200,000 fibers / cm, more preferably 2000 to 200,000 fibers / cm, and if the fiber thickness is 30 to 500 denier, 20 to 20,000 fibers / cm is preferred, and 200 is more preferred. ~ 20,000 / cm. If it is less than 20 fibers / cm, it is not possible to expect an increase in the amount of adhered microorganisms, and if it is more than 200,000 fibers / cm, the voids between the fibers that are napped will be reduced, and oxygen and substrates to the microorganisms adhered between the fibers, etc. Is insufficiently diffused, and the purification performance is reduced. The napped direction of the fibers is not particularly limited, but it is preferable that the fibers are separated from the core at an angle of 45 to 90 ° with respect to the length direction of the core. Also, as a method of raising the fibers from the core, when the fibers are in a loop shape,
A method of sandwiching it in the core while forming a loop in the fiber, or a method of drawing out from the material to be the core in the outer peripheral direction of the core is preferable, and when the fiber is a short fiber having a free end at the tip, fiber type, fiber length, etc. The method of performing electrostatic flocking or performing chenille processing in which the middle part of the fiber is sandwiched between a plurality of cores is preferable because it is easy to control.

On the other hand, when the porous structure is used as the cord, the porous structure is not particularly limited, and conventionally known ones can be used, such as a yarn bundle, a hollow fiber,
Examples thereof include a string, a woven fabric, a knitted fabric, a non-woven fabric, a fiber entangled body, a net, and a foaming body, or a combination thereof, or a complex of these with a polymer gel or a polymer resin. The porosity is preferably 70 to 99%, more preferably 80 to 99% from the viewpoint of improving the diffusion efficiency of oxygen and substrates in water.

The forested state of the cord-like material integrated with the shaft is rod-like having a free end at the tip, loop-like, or a combination thereof. Here, if it is a rod-shaped cord having a free end at the tip, it is possible to sufficiently supply oxygen and substrate to the microorganisms near the axis, and the sludge separated by the contact of the cords Be sure to drop it out of the carrier,
It is more preferable because clogging hardly occurs. In the case of a cord having a free end, the length from the root of the cord to the free end is preferably 5 mm or more, more preferably 1 cm.
It is more than 2 cm, more preferably more than 2 cm. When the thickness is 5 mm or less, the cord-like material does not swing, the self-cleaning property is poor, and the purification performance is deteriorated. The forest density of the cord-like material in the length direction of the shaft is not particularly limited and may be adjusted according to the property of the water to be treated, the shape of the cord-like material, the use, etc., but is 0.5 to 20. Book / cm is preferable, 1 to 1
5 lines / cm is more preferable. The direction in which the cords stand in the forest is not particularly limited, but the contact efficiency with the water to be treated,
From the aspect of microbial capture performance in the initial stage of device startup,
It is preferable that the shaft is separated from the shaft at an angle of 45 to 90 with respect to the longitudinal direction of the shaft.

The product of the present invention is preferably used for a water treatment device such as a contact aeration system, a biological deodorizing device, a direct purification of environmental water, or a bioreactor for producing a specific substance. In the water treatment device, the protrusions are arranged so that the protrusions oscillate due to the flow of the water to be treated and are in proper contact with each other,
A method of fixing in a treatment device such as a nitrification tank or a denitrification tank is preferably used. In this case, the contacts may be protrusions on the same axis or protrusions on adjacent axes. Further, in the biological deodorizing apparatus, a method of suspending the carrier in the apparatus without any space and flowing down the water in which the malodorous component is dissolved is preferably used. Also, in the direct purification of environmental water,
A method in which a carrier is installed in a suitable place where a water flow and dissolved oxygen can be secured is preferably used. Also, in the bioreactor,
It is used for the purpose of keeping a specific microorganism at a high concentration, and a method of installing a carrier at an appropriate position in the reactor is preferably used.

[0020]

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

Example 1 A polyester fiber (single yarn fineness: 8 denier, fiber length: 4 mm) was used to make a polyester core (total fineness: 3).
Bending degree of 4 by electrostatic flocking to 00 denier)
A cord-like material having a size of about 18 cm as measured by the 5 ° cantilever method was obtained. Next, this cord is cut into multiple pieces of about 8 cm, and the center of each piece is sandwiched between two shafts, which is screwed and fixed to make the forest stand in a direction perpendicular to the shaft and in a substantially radial symmetry. Got The density of cords on the shaft at this time was set to 7 cords / cm. A polymer obtained by quaternizing the above structure with a random copolymer of 4-vinylpyridine and styrene (copolymerization ratio 1: 1) with 4-vinylpyridine and an equimolar amount of benzyl chloride (molecular weight 5000). After sufficiently impregnating it with a 4% by weight ethanol solution of 1., it was dried in a hot air drier to obtain a microbial carrier having a property that the surface and the inside were positively charged in water. Four of these carriers (length: 30 cm) were arranged in the vertical direction in a contact aeration tank having a volume of 6 L at intervals of 10 cm. After adding seed sludge addition, artificial waste water with a BOD concentration of 250 ppm containing organic components and ammonia nitrogen as the main components was supplied at a BOD volume load of 2 kg / m ³ · d, and the treated water passed through a contact aeration treatment tank and a precipitation tank. The BOD concentration of was measured. The results are shown in Table 1.

Example 2 The structure obtained in Example 1 was treated with polyethyleneimine (molecular weight 25000) 3% in the presence of 3% by weight of carbodiimide.
By performing the same treatment except using a weight% methanol solution, a microbial carrier having a property that the surface and the inside thereof are positively charged in water was obtained. With this microbial carrier,
The same measurement as in Example 1 was performed. The results are shown in Table 1.

Example 3 The same measurement as in Example 1 was carried out using the same microbial carrier as in Example 1 except that the bending resistance of the cord-like material was about 9 cm as measured by the 45 ° cantilever method. . The results are shown in Table 1.

Comparative Example 1 The same measurement as in Example 1 was performed using the same microbial carrier as in Example 1 except that the bending resistance of the cord-like material was about 3 cm as measured by the 45 ° cantilever method. . The results are shown in Table 1.

[0025]

[Table 1] As is clear from Table 1, according to the examples in which the bending resistance of the cord-like material is moderate and the surface and the inside are positively charged in water, no matter what kind of substance is attached to the surface, , The device started up quickly, and after that, the shaft and the cord-like objects were shaken by the water flow, and the self-cleaning of microorganisms excessively attached to the cord-like substances was repeated, so that an appropriate amount of microorganisms was kept in a highly active state. , Showed stable processing performance. On the other hand, in the comparative example, stable performance was shown 3 weeks after the apparatus was started up, but the cord-like material had a small bending resistance, so the cord-like material was integrated with the shaft due to the load of the attached microorganisms, and the rod-like shape was formed. Therefore, the purification performance was significantly reduced.

Example 4 A non-woven fabric made of polyester having a thickness of 5 mm (single yarn fineness: 6 denier, porosity: 90%) was slit with a width of 5 mm, and a bending resistance of about 45 cm was measured by the cantilever method. The cord-like thing which is is obtained. Next, this cord-like material was cut into a plurality of pieces each having a length of about 8 cm, which was fixed by being twisted to obtain a structure which stands in a direction perpendicular to the axis and in a substantially radial symmetry. The density of the cord-like material on the shaft at this time was set to 2 cords / cm. A quaternized polymer was prepared by reacting a copolymer of 4-vinylpyridine and styrene with 4-vinylpyridine and an equimolar amount of benzyl chloride on the surface and inside of the carrier in the same manner as in Example 1. The microbial carrier thus obtained was obtained, and the same measurement as in Example 1 was performed. Table 2 shows the results.

Comparative Example 2 Same as Example 1 except that the copolymer of 4-vinylpyridine and styrene was reacted with 4-vinylpyridine and an equimolar amount of benzyl chloride to prevent the quaternized polymer from being attached. The same measurement as in Example 1 was carried out using the microbial carrier of. Table 2 shows the results.

Comparative Example 3 In the same manner as in Example 2, the same amount of nonwoven fabric was cut into strips having a width of 8 cm, three of them were laminated and the central portion was sewn to obtain a structure having a petal-shaped cross section. In this structure, a 4-vinylpyridine-styrene copolymer was prepared in the same manner as in Example 1.
The same measurement as in Example 1 was carried out by reacting vinyl pyridine and an equimolar amount of benzyl chloride to attach a quaternized polymer to obtain a microbial carrier. Table 2 shows the results.

Comparative Example 4 Similar to Comparative Example 3 except that a copolymer of 4-vinylpyridine and styrene was reacted with 4-vinylpyridine and an equimolar amount of benzyl chloride to prevent the quaternized polymer from being attached. The same measurement as in Example 1 was carried out using the microbial carrier of. Table 2 shows the results.

[0030]

[Table 2] As is clear from Table 2, according to the present invention, a sufficient amount of microorganisms adhere to the positively charged surface and the inside of water in about one week after the apparatus is started up, and treated water having a BOD of 20 ppm or less can be obtained. It was After that, since the cord-shaped nonwoven fabric and the shaft were shaken by the water flow, self-cleaning of excessively adhered microorganisms was repeated, so that an appropriate amount of microorganisms was kept in a highly active state and stable treatment performance was exhibited. On the other hand, in Comparative Example 2, it took time for the microorganisms to adhere and to exert the purification performance after the apparatus was started up, and in Comparative Example 3, the apparatus started up relatively quickly, but in long-term operation. However, the purification performance was deteriorated due to the adhesion of more than the required amount of microorganisms and the simultaneous exfoliation of attached microorganisms. The performance of Comparative Example 4 was low for the same reason as Comparative Examples 2 and 3.

[0031]

According to the present invention, the following effects are obtained by having the above-described configuration.

(1) The product of the present invention has a structure in which protrusions are widely projected to the outside from the shaft, and has a property that the surface and / or the inside thereof are positively charged in water. The performance is stable within a short period of time after the start of operation of the device.

(2) In the conventional carrier, deterioration of the purification performance due to partial clogging by sludge or collective peeling of biofilm was unavoidable after long-term use. Since the carriers are in constant contact with each other and the excessively attached microorganisms are appropriately removed, the microorganisms that have lost their activity do not stay on the surface of the carrier for a long time, and oxygen and the substrate are sufficiently diffused into the microorganisms attached to the carrier. The growth environment of is preferably maintained.

(3) Since the microbial carrier of the present invention can freely select the structure of the protrusions, it is possible to prepare carriers having various structures according to the use conditions.

(4) Since the biological treatment apparatus using the present invention does not cause clogging of the microbial carrier with sludge, maintenance is easy.

[Brief description of drawings]

FIG. 1 is a schematic view of the microbial carrier of the present invention as viewed from the axial direction.

FIG. 2 is a schematic view of the microbial carrier of the present invention viewed from a direction perpendicular to an axis.

FIG. 3 is a cord-like material in which napped fibers have free ends,
FIG. 3 is a schematic view of the microbial carrier of the present invention in which a cord-like material in which napped fibers are loop-shaped is present on the same axis as seen from a direction perpendicular to an axis.

FIG. 4 is a schematic view of a microbial carrier of the present invention in which a cord-like material in which napped fibers have a loop shape is present, as seen from a direction perpendicular to an axis.

FIG. 5 is a schematic view of the microbial carrier of the present invention in which the tips of napped fibers are free ends, as viewed in a direction perpendicular to the axis.

FIG. 6 is a schematic view of the microbial carrier of the present invention in which a fiber having a free end and a loop-shaped fiber are napped on the same core, as viewed from a direction perpendicular to an axis.

FIG. 7 is a schematic view of the microbial carrier of the present invention in which a cord-shaped material having a free end and a loop-shaped cord-shaped material are coaxially present, as viewed from a direction perpendicular to an axis.

FIG. 8 is a schematic view of the microbial carrier of the present invention in which the cord-like material has a loop shape as viewed from a direction perpendicular to the axis.

FIG. 9 is a schematic view of the microbial carrier of the present invention in which the protrusion has a porous structure, as viewed from a direction perpendicular to the axis.

[Explanation of symbols]

 1: axis 2: protrusions 3: napped fibers 4: looped napped fibers 5: cord-shaped protrusions 6: loop-shaped protrusions 7: protrusions that are porous structures

Claims (17)

[Claims] 1. A microbial carrier, characterized in that the shaft material has protrusions that can be positively charged in water. 2. The microbial carrier according to claim 1, wherein the shaft is swingable. 3. The microbial carrier according to claim 1, wherein the protrusion is a cord. 4. The microbial carrier according to claim 3, wherein the tip of the cord-like material is a free end. 5. The bending resistance of the cord-like material is JIS L1085.
The microbial carrier according to claim 3, which has a size of 6 cm or more in the measurement by the 45 ° cantilever method described above. 6. The microbial carrier according to claim 4, wherein the length from the root to the free end of the cord-like material is 2 cm or more. 7. The microbial carrier according to claim 3, wherein the cord-like material has a form in which napped fibers are present around a core material. 8. The microbial carrier according to claim 7, wherein the tips of the napped fibers are free ends. 9. The microbial carrier according to claim 7, wherein the napped fibers are napped in a loop. 10. The microbial carrier according to claim 8, wherein the napped fibers are obtained by electrostatic flocking. 11. The microbial carrier according to claim 7, wherein the napped fibers are obtained by chenille processing. 12. The length from the root to the free end of the napped fiber is 0.5 to 8 mm.
A microorganism carrier according to item 1. 13. The microbial carrier according to claim 7, wherein the napped density of the fibers in the length direction of the core is 2000 to 200,000 fibers / cm. 14. The microbial carrier according to claim 3, wherein the code-like material is a porous structure. 15. The shaft is composed of at least two filaments, the filaments are twisted independently, and the filaments are twisted with each other to sandwich and hold the protrusion. The microbial carrier according to claim 1. 16. The microbial carrier according to claim 1, wherein the surface and / or the inside of the protrusion has a pyridinium group. 17. A biological treatment apparatus comprising the microbial carrier according to claim 1.