JP2001300574A - Microorganism carrier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microorganism carrier which has durability and excellent microorganism implantability, lessens the laboriousness of operation and can reduce a running cost. SOLUTION: The microorganism carrier consists of structures in which loops are formed by continuous filaments consisting of thermoplastic resins and the greater part of the each other's contact parts are joined. The sectional shapes of the filaments have recessed shapes and the relationship between the sectional area (S0) of the circumcircle of the sectional shapes and the sectional area (Su) of the recessed parts satisfies 20>=(S0)/(Su).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microorganism carrier for purifying dirty water by propagation of microorganisms without causing environmental pollution. Further, the present invention relates to a microorganism carrier optimal for a purification device using an aeration tank.

[0002]

2. Description of the Related Art As disclosed in Japanese Patent Application Laid-Open No. 51-59451, a method is disclosed in which a net is installed in an aeration tank and microorganisms are carried on the net and propagated to purify sewage. . In this method, a large amount of labor is required for forming a structure in which a plurality of nets are stacked, and there is a problem of cost. In addition, there is a problem that handling becomes poor because the structure becomes heavy. Japanese Patent Application Laid-Open No. 53-125359 discloses the use of a nonwoven fabric having a network structure in which fibers such as nylon, vinylidene chloride, and vinyl chloride are curled, formed into a web or mat, and thermally bonded, as a microorganism carrier. Have been. This carrier has a problem that the function of adhering microorganisms is still insufficient. JP-A-6-190386
The publication discloses a three-dimensional network in which linear shapes (diameter 6 mm, length 3 mm in Examples) of polypropylene and polyethylene with little contaminants are intertwined in an irregular shape, and carbon black, metal powder, One kind of carbon black, metal powder, barium sulfate, calcium sulfate, calcium carbonate, etc. is adhered to a microorganism carrier or polypropylene network exposed on the surface by kneading one kind of barium sulfate, calcium sulfate, calcium carbonate, etc. A microbial support for water purification is disclosed in which the microbial support is compared with a polypropylene net and a vinylidene chloride mat. Also in this carrier, there is a problem that only the surface area of the striated line becomes an attachment surface of microorganisms, and the microorganism attachment function is insufficient. Japanese Patent Application Laid-Open No. 9-220587 discloses a flow-type purifying apparatus with a stirring action.
A reticulated flat cylindrical body is disclosed. This reticulated flat cylindrical body is a microorganism carrier obtained by cutting polyethylene or polypropylene having a wire diameter of 0.5 to 2 mm into a cylindrical body diameter of 6 to 30 mm and a cylindrical body length of 6 to 30 mm. This microorganism carrier is obtained by extrusion molding into a reticulated tubular body, flattening and cutting, but because the wire diameter is large and the length of the filament is short, the surface area of the filament in the carrier is reduced and the microorganism carrier is reduced. There is a problem that the landing amount is restricted.

As a microorganism carrier for a fluid-type water purification treatment apparatus, a method for improving the purification efficiency by miniaturization to enhance the establishment of contact with microorganisms, for example, JP-A-9-28528
In Japanese Patent Publication No. 7, the spherical diameter of the hollow portion connected to the outside is 1.5 to
A 6 mm hollow sphere has been proposed. The carrier is intended to simultaneously implant aerobic microorganisms and anaerobic microorganisms to improve purification efficiency. In this proposal, it is complicated to prepare a microorganism carrier, and it is necessary to separate and recover the carrier to regenerate or additionally replenish the carrier, resulting in a problem of complicated operation and an increase in running cost. Also, JP-A-10-17
Japanese Patent Publication No. 4989 proposes a microbial carrier made of hollow tubular plastic having an outer shape and a tube length of 10 mm or less. The microorganism carrier carries microorganisms in the tube to aerate aerobic microorganisms with air and anaerobic microorganisms with an inert gas to improve purification efficiency. Also in this proposal, it is necessary to separate and collect the microorganism carrier for regeneration or additional replenishment. Further, it is also necessary to change the type of aeration gas, and the operation is complicated and the running cost is increased.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and provides a microorganism carrier which is durable, has excellent microorganism-implantability, reduces the complexity of operation, and can reduce running costs. The purpose is to do.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies in order to achieve the above object, and as a result, continuous filaments having a hollow ruptured section made of a thermoplastic resin form a loop,
The present invention has been achieved by using a structure in which most of the contact portions are joined to each other.

That is, according to the first aspect of the present invention, there is provided a structure in which a continuous filament made of a thermoplastic resin forms a loop and most of the contact portions are joined to each other.
The cross-sectional shape of the filament has a concave portion, and the relationship between the circumscribed circular cross-sectional area (S0) of the cross-sectional shape and the concave cross-sectional area (Su) is 20 ≧ (S
0) / (Su).

According to a second aspect of the present invention, in the microorganism carrier according to the first aspect, the maximum width (B
The relationship between i) and the opening width of the recess (Bw) is Bi / Bw ≧ 1.
Is satisfied.

According to a third aspect of the present invention, in the microorganism carrier according to the first or second aspect, the thermoplastic resin is a thermoplastic elastic resin.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The thermoplastic resin in the present invention refers to a resin which is thermoplastic and can be melt-spun. For example,
Examples include polyester, polyamide, polyolefin, polyurethane, polyvinyl alcohol, polyvinylidene chloride, polyvinyl chloride, and the like. In the present invention, it is preferable to use one having a glass transition temperature of at least 40 ° C. or higher. For example, for polyester, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycyclohexylene dimethylene terephthalate (PCHDT), polycyclohexylene dimethylene naphthalate (PCHDN), Butylene terephthalate (PBT), polybutylene naphthalate (PB
N), polyarylate and the like, and copolymerized polyesters thereof and the like. Polyamides include polycaprolactam (NY6) and polyhexamethylene adipamide (NY
66), polyhexamethylene sebacamide (NY6-1)
0) and their copolymerized polyamides. Examples of the polyolefin include polyethylene (PE), polypropylene (PP), polybutene-1 (PB · 1), and a copolymerized polyolefin thereof. As the thermoplastic resin used in the present invention, for example, when used in an individual septic tank in a hotel or the like, in consideration of the inflow of hot water, polyester and polyamide having good heat resistance, polyamides, and olefins having a high glass transition point are particularly used. preferable. Furthermore, it is most preferable that the composition does not contain a chemical or the like that causes environmental pollution and passes the voluntary standards for food containers made of synthetic resin such as polyolefin.

For example, as a polyester elastomer, a thermoplastic polyester is used as a hard segment,
Examples thereof include a polyester ether block copolymer having a polyalkylenediol as a soft segment and a polyester ester block copolymer having an aliphatic polyester as a soft segment. Polyester d
More specific examples of terblock copolymers include terephthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, diphenyl
Aromatic dicarboxylic acids such as -4.4'-dicarboxylic acid;
An alicyclic dicarboxylic acid such as 4-cyclohexanedicarboxylic acid, an aliphatic dicarboxylic acid such as succinic acid, adipic acid, sebacic acid dimer acid, or at least one dicarboxylic acid selected from ester-forming derivatives thereof; ,
Aliphatic diols such as 1,4-butanediol, ethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, and 1,1-cyclohexanediol Methanol,
Alicyclic di- such as 1,4-cyclohexanedimethanol
Or at least one diol component selected from ester-forming derivatives thereof, and polyethylene glycol, polypropylene glycol, polytetramethylene glycol having an average molecular weight of about 300 to 5,000.
And a triblock copolymer comprising at least one of polyalkylenediols such as glycols and ethylene glycol-propylene oxide copolymers.

As the polyester ester block copolymer, a ternary block copolymer composed of at least one of the above dicarboxylic acids and at least one of diols and polyester diols such as polylactone having an average molecular weight of about 300 to 5,000 is used. It is united. In consideration of thermal adhesion, hydrolysis resistance, stretchability, heat resistance, etc., terephthalic acid or naphthalene-2,6-dicarboxylic acid as a dicarboxylic acid, and 1,4-butanedioxide as a diol component. As the polyalkylenediol, a triblock copolymer of polytetramethylene glycol or a polyesterdiol as a triblock copolymer of polylactone is particularly preferable. In a special case, those incorporating a polysiloxane-based soft segment can also be used. Also,
The thermoplastic elastomer resin of the present invention also includes those obtained by blending the above elastomer with a non-elastomer component, copolymerized product, and polyolefin-based component made into a soft segment.

[0012] Polyamide-based elastomers include
Nylon 6, nylon 66, nylon 6 for the do segment
10, nylon 612, nylon 11, nylon 12, etc. and their copolymerized nylon as a skeleton, and the soft segment includes polyethylene glycol, polypropylene glycol, polytetramethylene glycol having an average molecular weight of about 300 to 5000. A block copolymer composed of at least one of polyalkylenediols such as a glycol composed of an ethylene oxide-propylene oxide copolymer may be used alone or as a mixture of two or more. Further, those in which a non-elastomer component is blended or copolymerized can be used in the present invention.

As the polyurethane elastomer, (A) a number average molecular weight of 1 in the presence or absence of a usual solvent (dimethylformamide, dimethylacetamide, etc.)
(B) a polyisocyanate having an organic diisocyanate as a main component obtained by reacting a polyether and / or polyester having a hydroxyl group at a terminal of 000 to 6000 with an isocyanate group at both terminals; A typical example is a polyurethane elastomer which is chain-extended by a polyamine containing a diamine as a main component. The polyester and polyethers (A) have an average molecular weight of about 1000 to 6000, preferably 1300 to 5000.
Polybutylene adipate copolymer polyester or polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyalkylene diols such as glycols composed of ethylene oxide-propylene oxide copolymers are preferred, As the polyisocyanate-polyisocyanate (B), a conventionally known polyisocyanate can be used, and diphenylmethane-4 ·
An isocyanate mainly composed of 4'-diisocyanate is used, and if necessary, a conventionally known triisocyanate or the like may be added in a small amount. As the polyamine (C),
Known diamines such as ethylenediamine and 1,2-propylenediamine may be mainly used, and trace amounts of triamine and tetraamine may be used in combination as needed. These polyurethane elastomers may be used alone or in combination of two or more.

The melting point of the thermoplastic elastic resin of the present invention is preferably 140 ° C. or higher which can maintain the heat resistance and durability.
It is more preferable to use one having a temperature of 160 ° C. or higher because the heat resistance and durability are improved. In addition, durability can be improved by adding an antioxidant, a light stabilizer, or the like, if necessary. Most preferably, they pass the voluntary standards for food containers made of synthetic resin such as polyolefin.

[0015] The content of the soft segment of the thermoplastic elastic resin constituting the component having elasticity, impact absorbing function and durability as the microorganism carrier as the object of the present invention is preferably 10% by weight or more and 70% by weight or less. And more preferably 15% by weight or more and 60% by weight or less.

When the microorganism carrier of the present invention is made of a thermoplastic elastic resin, it preferably has an endothermic peak below its melting point in a melting curve measured by a differential scanning calorimeter. Those having an endothermic peak below the melting point have significantly improved stretch recovery properties than those having no endothermic peak.
Improves shock absorption and shape retention.

Preferred polyester-based thermoplastic resins in the present invention include terephthalic acid and naphthalene-2,6-dicarboxylic acid having a rigid acid component in the hard segment. The content of terephthalic acid or naphthalene-2,6-dicarboxylic acid is at least 90 mol%, preferably 95 mol%.
Mol% or more, particularly preferably 100 mol%. These acid components are transesterified with the glycol component and then polymerized to a required degree of polymerization. Then, as a polyalkylenediol, the polyalkylenediol preferably has an average molecular weight of 500 to 5,000, particularly preferably 1,000 to 3,000. The copolymer is obtained by copolymerizing tetramethylene glycol in an amount of 15 to 70% by weight, more preferably 30 to 60% by weight. When the content of terephthalic acid or naphthalene-2,6-dicarboxylic acid, which has rigidity in the acid component of the hard segment, is large, the crystallinity of the hard segment is improved, plastic deformation is difficult, and heat resistance is reduced. Although the resilience is improved, an annealing treatment at a temperature lower by at least 10 ° C. than the melting point after the fusion heat bonding further improves the elongation recoverability.

Annealing after imparting a compressive strain further improves the elongation recoverability. Those treated in such a manner more clearly show an endothermic peak in a melting curve measured by a differential scanning calorimeter at a temperature from room temperature to the melting point. When no annealing is performed, an endothermic peak does not appear in the melting curve from room temperature to the melting point. By analogy with this,
By annealing, the hard segments are rearranged,
It is also considered that pseudo-crystallization-like cross-linking points are formed and the stretch recovery is improved. In the present invention, this processing is defined as a pseudo crystallization processing. This pseudo-crystallization effect is also effective for other thermoplastic elastic resins, for example, polyamide-based elastic resins and polyurethane-based elastic resins.

According to the present invention, there is provided a structure in which a continuous filament made of a thermoplastic resin forms a loop, and most of the contact portions are joined to each other. Wherein the relationship between the circumscribed circle cross-sectional area (S0) and the concave cross-sectional area (Su) satisfies 20 ≧ (S0) / (Su).

In the present invention, the term “cross section having a concave portion” means a cross section having an opening at the outer periphery of a linear cross section and having a concave portion from the periphery of the cross section. For example, C-shaped cross section,
Examples include a horseshoe-shaped cross section, a V-shaped cross section, a U-shaped cross section, and a star-shaped cross section.

In the present invention, the thermoplastic resin can be directly formed into a structure in which continuous filaments having a cross section having a concave portion form a loop by melt spinning and most of the contact portions of the thermoplastic resin are joined to each other. The body can be obtained and manufactured at low cost. In addition, by forming a structure in which a continuous filament having a cross section having a concave portion forms a loop and most of the contact portions are joined to each other, the surface area of the filament can be increased as compared with the round cross section, so that microorganisms can be attached. The floor can be more.

The cross-sectional area (Su) of the concave portion required for the present invention is such that the relationship between the circumscribed circular cross-sectional area (S0) of the cross-sectional shape and the concave cross-sectional area (Su) satisfies 20 ≧ (S0) / (Su). is necessary. When 20 ≧ (S0) / (Su) is not satisfied, the area for implantation of microorganisms becomes insufficient, and it becomes difficult to provide an efficient water purification function. In the present invention, the relationship between the concave cross-sectional areas is preferably 10 ≧ (S0) / (Su), and more preferably 8 ≧ (S0) / (Su).

The diameter of the filament of the microorganism carrier of the present invention is not particularly limited, but the preferred diameter of the filament is 0.05 mm or more and less than 1 mm. If the wire diameter is too small, the joining of the loops may be insufficient, and the shape may be unfavorably deteriorated due to softness. If the wire diameter is too large, the surface area of the filament per apparent density is reduced, and the amount of microorganisms to be implanted is reduced. A more preferable wire diameter is
0.1 mm or more and 0.8 mm, most preferably 0.2 mm
It is 0.5 mm or less.

The apparent density of the microorganism carrier of the present invention is not particularly limited, but the preferred apparent density is 0.01 g / cm.
³ or more and 0.3 g / cm ³ or less. If the apparent density is too low, the shape retention is inferior, and the area where the microorganisms can be implanted decreases with a decrease in the number of components, which is not preferable. If the apparent density becomes too high, the number of components increases, the number of joints increases, and the shape retention is improved.However, the decrease in voids limits the growth area of microorganisms, and at the same time, reduces the flow resistance of flowing water. And the aeration effect is reduced, which is not preferable. A more preferred apparent density of the present invention is 0.02
g / cm ³ or more and 0.25 g / cm ³ , and most preferably 0.03 g / cm ³ or more and 0.20 g / cm ³ or less.

In a preferred embodiment of the present invention, the relationship between the maximum width (Bi) of the concave portion of the linear cross section and the width of the concave portion opening (Bw) satisfies the relationship of Bi / Bw ≧ 1. Can be prevented from peeling off. Furthermore, by satisfying the relationship of Bi / Bw ≧ 2, it can be used as a microorganism carrier capable of holding aerobic microorganisms on the surface and holding aversive microorganisms inside the concave portions. Thus, the purification function of the aerobic microorganisms and the purification function of the anaerobic microorganisms can be simultaneously operated to increase the purification efficiency. Examples of the cross-sectional shape in which such an effect can be expected include a C-shaped cross section and a horseshoe cross section.

In a more preferred embodiment of the present invention,
A microorganism carrier using a thermoplastic elastic resin as the thermoplastic resin. By using a thermoplastic elastic resin, the rubber elasticity of the thermoplastic elastic resin expands and contracts even if deformed by stress, and recovers its original shape. Is particularly preferred since it significantly improves

In the present invention, it is 199 to pass the voluntary standard for food containers made of synthetic resin such as polyolefin.
It refers to a composition conforming to the contents described in the third edition limited edition of the voluntary standards for food containers made of synthetic resins such as polyolefins issued by the Polyolefin Sanitation Council in March 1995. As an example of the most preferred embodiment of the present invention, purified water discharged from rivers, lakes, marshes, harbors, etc. is obtained by using a microorganism carrier using a composition that passes voluntary standards for food containers made of synthetic resin such as polyolefin. It is a microbial carrier with good environmental compatibility due to low secondary contamination of the microorganism.

When used in a purification apparatus for high-speed biological treatment, the outer periphery of the microbial carrier, which has been cut into small pieces, is joined to form a large impact force due to agitation or aeration, or the streaks or peeling of the filament due to the collision of the microbial carrier. This is a preferred embodiment of the present invention, since the shape retention is prevented and the form retention is further improved.

Next, an example of the production method of the present invention will be described. A thermoplastic resin or a thermoplastic elastic resin (preferably, a composition that passes voluntary standards for food containers made of synthetic resin such as polyolefin when an additive is contained) from a multi-row nozzle having a plurality of concave section forming orifices. It is distributed to each nozzle orifice and discharged downward from the nozzle at a melting temperature higher than the melting point of the thermoplastic resin by 10 ° C. or more and lower than 120 ° C., and is brought into contact with each other in a molten state to be fused to form a three-dimensional structure. After being formed, it is sandwiched by a take-off device, cooled in a cooling tank, and then cut into a desired length to obtain a sheet-like net-like structure.

The cross-sectional area (Su) of the concave portion required for the present invention is such that the relationship between the circumscribed circular cross-sectional area (S0) of the cross-sectional shape and the cross-sectional area of the concave portion (Su) can satisfy 20 ≧ (S0) / (Su). As an orifice, the orifice cross-section is held in a C-shaped one-bridge or triple-bridge in the concave cross-section forming orifice, and the resin discharge hole is slit-shaped to increase the width of one bridge. In the case of joining by the ballast effect after inhaling the gas immediately after the molten filament is discharged, a method of obtaining a filament in which the hollow portion is ruptured without joining at one point, using a U-shaped, Y-shaped, star-shaped orifice, etc. A method for obtaining a linear section such as a mold section, a Y-section, and a star-shaped section can be adopted.

The wire diameter is determined by the balance between the shape of the orifice, the discharge amount of a single hole, the melt viscosity and the distance of the take-off point. When the orifice diameter is reduced, the diameter tends to be small, but when the discharge amount is large, the diameter becomes large. If the amount is too small, it is easy to cool and the joining of the contacts may be insufficient, which is an unfavorable condition. The lower the melt viscosity, the easier it is to make it thinner by falling under its own weight, but it is necessary to maintain a molecular weight capable of maintaining the strength as a microorganism carrier. The longer the take-up point distance from the orifice, the thinner. However, if the length is too long, the cooling is excessive, and the formation of the network structure becomes insufficient. Therefore, it is necessary to set an optimum take-off point distance.

In the present invention, it can be used as a microorganism carrier in a sheet form as it is. Even when the sheet is used as it is, when a thermoplastic elastic resin is used as the material, it is preferable to perform a pseudo-crystallization treatment as described above.

When used in an apparatus which receives a large impact, such as an aeration tank for performing a fluidized high-speed purification treatment, an arbitrary shape (for example, 30 mm to 50 mm square or φ30 mm to φ)
The outer periphery is joined by means of hot pressing with a mold so as to form a 50 mm circle or a sphere or the like by punching or cutting using an ultrasonic welder (the reinforcing effect is large). preferable. Even when a large shock is not applied, if use and maintenance become easy, the product can be cut to an arbitrary size and used.

The microorganism carrier obtained in this manner can carry and grow microorganisms on a structure composed of striata, thereby purifying sewage efficiently.

[0035]

The present invention will be described in more detail with reference to the following Examples, which, however, are not intended to restrict the scope of the present invention. The evaluation in the examples was performed by the following method.

(B) Relationship between the cross-sectional area of the concave portion and the cross-sectional area of the circumscribed circle Each linear portion is cut out of the sample from 10 places, embedded in acrylic resin, the cross-section is cut out, and a section is prepared to obtain a cross-sectional photograph. Draw a circumscribed circle from the cross-sectional photograph of each part and obtain the circumscribed circle cross-sectional area (S0). Next, the cross-sectional area (Su) of each recess is obtained, and (S0) / (Su) is calculated by the following equation. S0 / Su = [1 / nΣ (S0)] / [1 / nΣ (S
u)]

(B) Relationship between the maximum width of the concave portion and the opening width The maximum width of the concave portion (Bi) and the width of the concave portion opening (B
w), and Bi / Bw is calculated by the following equation. Bi / Bw = [1 / nΣ (Bi)] / [1 / nΣ (B
w)] (c) Wire diameter (D) The maximum diameter (unit: mm) is determined from the above cross-sectional photograph, and is defined as the wire diameter.

(D) Apparent density (1) Large sample A sample is cut into a size of 15 cm × 15 cm, the height of four places is measured, the volume is determined, and the weight of the sample is reduced by the volume. (Average value of n = 4). (2) Small sample The circumscribed volume of the entire sample is determined, and the weight of the entire sample is expressed by a value described by volume (average value of n = 4).

(E) Water quality evaluation The following items were measured in accordance with the JIS method. Turbidity (JIS
K010), BOD (JIS K0102.21)
32.3), ammonia nitrogen, nitrite nitrogen.

(F) Adhered state of microorganisms The state of adhering microorganisms is visually evaluated by grading. Grade 5: Very large. Grade 4: Many. Level 3: Normal. Grade 2: Less. Grade 1: Very little adhesion. Grade 0: No adhesion.

(G) Melting point (Tm) and endothermic peak below the melting point (Tαcr) Endothermic curve measured at a heating rate of 20 ° C./min using a TA50, DSC50 type differential thermal analyzer manufactured by Shimadzu Corporation. , The endothermic peak (Tm and Tαcr) temperatures were determined.

(H) Joining By visually judging the samples, it is judged that the streaks that are in contact with each other are lightly pulled, and those that do not separate are joined. Whether or not the outer peripheral portions are joined is judged to be joining if the joined fibers are not detached by pulling them by hand.

Example 1 As polyester-based elastomers, dimethyl terephthalate (DMT) and 1,4-butanediol (1.4B
D) was charged with a small amount of a catalyst, transesterified by a conventional method, polytetramethylene glycol (PTMG) was added, and polycondensation was performed while raising the temperature and pressure to form a polyetherester block copolymer elastomer, Next, Adeka stub AO330 manufactured by Asahi Denka Kogyo as an antioxidant was 0.2%.
Table 1 shows the formulation of the thermoplastic elastic resin raw material obtained by mixing, kneading, pelletizing, and vacuum drying at 50 ° C for 48 hours.

[0044]

[Table 1]

An orifice hole having a staggered arrangement with a pitch of 5 mm in the width direction formed on a nozzle effective surface having a width of 50 mm and a length of 700 mm has a C type having an outer diameter of 4 mm and an inner diameter of 3.6 mm, and a bridge width of 0.5 mm. The obtained thermoplastic elastic resin raw material (A-1) was discharged downward at a melt spinning temperature of 240 ° C. and a single hole discharge rate of 1.98 g / min using a nozzle (1546 holes). Cooling water is arranged 100 mm below the nozzle surface, and a pair of take-up conveyors are arranged in parallel with a stainless steel endless net having a width of 1000 mm at an interval of 45 mm so as to partially emerge on the water surface. A three-dimensional network structure is formed while forming a meandering loop and joining the contact portions, and the two sides of the molten network are sandwiched between take-up conveyors at a speed of 2 m / min.
A 4.5 cm-thick sheet-like structure made of a thermoplastic elastic resin obtained by drawing into cooling water at 5 ° C. and solidifying to flatten both sides, and then cutting into 2 m, has a horseshoe-shaped cross-sectional shape of the filament, and has a S0 / Su was 3.1, Bi / Bw was 1.3, and the wire diameter was 0.6 mm. The average apparent density was 0.05 g / cm ³ . Subsequently, the structure was pseudo-crystallized with hot air at 105 ° C. for 20 minutes to obtain a structure B1 of the present invention having an endothermic peak at 116 ° C. below the melting point.

100 liters of reservoir water with a turbidity of 20 degrees and a BOD of 35 mg / liter was placed in the water tank 1 of FIG.
1 cm of microbial carrier C1 cut to 18 cm in length.
1 were placed in the carrier storage tank 2 of FIG. 1 and circulated at 20 CC / min using the circulation pump 3. Five aquariums were placed in the aquarium and fed with 3 g of food once a day and raised for 30 days. The room temperature was kept at 25 ° C., and the water evaporated once every 10 days was added with tap water. Table 2 shows the water quality in the water tank measured after 30 days. The amount of microorganisms adhering to the microorganism carrier in the carrier storage tank was quaternary. Table 2 shows that the present invention of Example 1 is excellent in water purification function. The microorganism carrier holding the collected microorganisms was easily washed with a water stream.

Comparative Example 1 A 1 mm-diameter circular cross-section orifice nozzle (2108 holes) in a staggered arrangement with a hole pitch of 5 mm was used for MI.
Using 100 polypropylene, a single hole discharge amount of 1.5 g /
Min, and the sheet-like structure (microbial carrier B2) was obtained in the same manner as in Example 1 except that the pseudo-crystallization treatment was not performed.
) Has a round cross-section, is formed by a filament having a wire diameter of 1.2 mm, and has an average apparent density of 0.05 g / c.
m ³ . Table 2 shows the results of evaluating the water purification function of the cut microorganism carrier C2 after 30 days in the same manner as in Example 1. The amount of microorganisms adhering to the microorganism carrier in the carrier storage tank was second class. From Table 2, it can be seen that Comparative Example 1, which deviates from the present invention, has a slightly poorer water purification function.

[0048]

[Table 2]

[0049]

The present invention has the following effects by having the above-described structure. In a structure in which a continuous filament made of a thermoplastic resin forms a loop and most of the contact portions are joined to each other, the cross-sectional shape of the filament has a concave portion,
Circumscribed circular cross-sectional area (S0) and concave cross-sectional area (Su)
Is a microbial carrier that satisfies 20 ≧ (S0) / (Su), the microbial carrying capacity is excellent due to the large surface area, the water flow is easy to circulate, the contact effect is large, and the microorganism adheres to the carrier. Because of the structure that can maintain good environment for growing microorganisms, high purification efficiency can be maintained for a long time. In addition, since it has good durability, can be used for a long time, and can be easily washed after use and can be reused, the complexity of operation can be reduced and the running cost can be reduced. In a preferred embodiment of the present invention, the relationship between the maximum width (Bi) of the concave portion and the opening width (Bw) of the concave portion in the linear cross section satisfies the relationship of Bi / Bw ≧ 1, thereby supporting the microorganism carrier. It is possible to prevent peeling of the microorganisms. Furthermore, by satisfying the relationship of Bi / Bw ≧ 2, it can be used as a microorganism carrier capable of holding aerobic microorganisms on the surface and holding aversive microorganisms inside the concave portions. Thus, the purification function of the aerobic microorganisms and the purification function of the anaerobic microorganisms can be simultaneously operated to increase the purification efficiency. In addition, by using a thermoplastic elastic resin, it is possible to withstand a large impact force and maintain a good water purification function for a long time. Furthermore, by using a microorganism carrier using a composition that passes voluntary standards for food containers made of synthetic resin such as polyolefin, etc., the purified water discharged does not cause secondary pollution to rivers, lakes, harbors, etc. It is a microorganism carrier having good environmental compatibility.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an evaluation device relating to a microorganism carrier of the present invention.

[Explanation of symbols]

 1: Water tank 2: Carrier storage tank 3: Pump

Claims (3)

[Claims] 1. A structure in which a continuous filament made of a thermoplastic resin forms a loop and most of its contact portions are joined to each other. The relationship between the circular sectional area (S0) and the concave sectional area (Su) is 2
A microorganism carrier which satisfies 0 ≧ (S0) / (Su). 2. The microorganism carrier according to claim 1, wherein the relationship between the maximum width (Bi) of the concave portion in the linear cross section and the concave portion opening width (Bw) satisfies the relationship of Bi / Bw ≧ 1. 3. The microorganism carrier according to claim 1, wherein the thermoplastic resin is a thermoplastic elastic resin.