JP2012024700A - Microorganism carrier for sewage treatments, and sewage treatment tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new high-performance microorganism carrier which is used by making it flow under the water flowing condition in a sewage treatment tank and solves various drawbacks of the conventional microorganism carrier.SOLUTION: The microorganism carrier 1 for sewage treatment is a fiber aggregate having a ball-like portion 3 and a convergent portion 5 of the edge parts thereof. The void ratio of the ball-like portion 3 to the apparent volume of the portion 3 is 90-99 vol.%, and the average interval of the fiber composing the ball-like portion 3 is 0.01 to 0.5 in the formula: average interval=[apparent volume of the ball-like portion (cm)]×[void ratio of the ball-like portion (vol.%)]/[total length of fibers composing the ball-like portion (cm)].

Description

  The present invention relates to a microorganism carrier for sewage treatment and a sewage treatment tool, and in particular, fluidly contact a carrier that is accommodated in a sewage treatment tank such as an activated sludge tank and has microorganisms settled under flowing water conditions. The present invention relates to a microorganism carrier for sewage treatment and a sewage treatment tool that are preferably used for treating pollutants in waste water.

  2. Description of the Related Art Conventionally, sewage treatment microorganism carriers used under running water conditions in a sewage treatment tank, so-called fluid carriers, have been proposed in various shapes. For example, Patent Document 1 proposes a microbial support for treating sewage in a ball shape (marimo form) formed by a thin fiber assembly imparted with crimps. In addition, a microorganism-supporting body for sewage treatment in which these ball-shaped fiber assemblies are put in a protective container has also been proposed. For example, Patent Document 2 discloses a shape-retaining mesh container and a plurality of water-retentive nodules. A microbial carrier for sewage treatment has been proposed, characterized in that a plurality of water-retentive nodules are accommodated in a shape-retaining mesh container so as to be flowable under flowing water conditions in a sewage treatment tank. .

Japanese Utility Model Publication No. 62-24997 JP-A-7-290079

  When the above-mentioned ball-shaped fiber assembly is used as a fluid carrier, the specific surface area is large compared to the volume and small microorganisms such as bacteria when compared with a sponge or hollow cylinder widely used as an existing fluid carrier. Although it is considered that the implantation of the group is advantageous, in reality, the adhesion of bacteria is not uniform for the specific surface area, and the water treatment effect is not improved.

  This is because, for example, in the case of an aeration-type sewage treatment tank, oxygen due to aeration cannot enter the fiber assembly, bacteria cannot be implanted, or relatively large protozoa such as earthworms are present in the ball-shaped fiber assembly. It is presumed that the food chain in the system is incomplete due to inability to enter the interior, and there is a problem that the sewage treatment capacity including sludge reduction will not be improved. Actually, the microbial support for sewage treatment has not been widely used. This defect is particularly noticeable particularly when the fibers forming the ball-like fiber aggregate are thin and densely packed, or when the fibers are hardened with an adhesive such as latex.

  Furthermore, when the ball-shaped fiber assembly is used as a fluid carrier that flows under flowing water conditions in the sewage treatment tank, the action of the water flow, the collision of the ball-shaped fiber aggregates, or the ball-shaped fiber aggregate and the treatment tank wall There may be a drawback in that the active microorganism group and the protozoan group such as earthworms dropped on the ball-like fiber assembly drop off due to the impact or deformation caused by the collision with the sewage, and the sewage treatment ability is reduced. In this type of sewage treatment microorganism carrier, there has been a demand for a novel high-performance carrier that solves the various disadvantages of the conventional sewage treatment microorganism carrier as described above.

  The present invention has been made in view of the above circumstances, and its purpose is to provide a sewage treatment microorganism carrier that exhibits a high sewage treatment effect when used under flowing water conditions in a sewage treatment tank, and It is in providing the sewage treatment tool using this.

  As a result of intensive studies, the present inventors have found that when a ball-shaped fiber assembly is used as a microorganism support for sewage treatment that can flow under running water conditions in a sewage treatment tank, the appearance of the ball-shaped fiber assembly is apparent. The average inter-fiber distance obtained by the formula obtained by dividing the volume multiplied by the void volume and the total length of the fiber was found to exhibit extremely high sewage purification capability in a specific range, and finally the present invention was completed. It came to do.

Specifically, the sewage treatment microorganism carrier of the present invention is a sewage treatment microorganism carrier composed of a fiber assembly in which fibers are aggregated, and the fiber assembly includes a ball-shaped portion that forms a ball shape. A converging portion that is formed at an end of the ball-shaped portion to converge the fibers, and the void ratio of the ball-shaped portion is 90 to 99% by volume with respect to the apparent volume of the ball-shaped portion, It is the microorganisms carrier for sewage treatment whose average space | interval represented by the following Formula (1) of the fiber which comprises a ball-shaped part is 0.01-0.5.
Average interval = apparent volume of ball-shaped part (cubic cm) × porosity of ball-shaped part (volume%) / total length of fibers constituting ball-shaped part (cm) (1)

  Surprisingly, the microorganism carrier for sewage treatment that satisfies the above conditions has a small amount of microbes such as bacteria uniformly living inside the ball-shaped part, and in addition, a large number of relatively large protozoa such as earthworms are also present. The food chain system of microorganisms in the system functions and the sewage treatment capacity including sludge reduction is dramatically improved.

  Moreover, it is preferable that the fiber which comprises the said fiber assembly is a polyvinylidene chloride type fiber containing 80 to 99 weight% of vinylidene chloride resin. According to this configuration, although the reason is unknown, the implantation of microorganisms and protozoan groups is much faster than other resins such as polypropylene and polyester, and the sewage treatment capacity is further increased.

  Moreover, it is preferable that the fiber assembly includes a plurality of ball-shaped portions, and the plurality of ball-shaped portions are connected in a daisy chain via the converging portion. For example, considering the case where the fiber assembly is stored in a capsule or the like, it is easier to store the bead-like fiber assembly than the case where the ball-shaped fiber assembly is stored in a plurality of capsules or the like. This is preferable.

  Further, a sewage treatment tool of the present invention comprises any one of the above sewage treatment microorganism carriers and a spherical lattice-shaped capsule container that accommodates the sewage treatment microorganism carrier, and the appearance of the capsule container The sewage treatment tool has a total apparent volume of 10 to 50% by volume of the sewage treatment microorganism carrier to be housed. When the sewage treatment microorganism carrier is stored in a spherical lattice-shaped capsule container, it can be protected from impact from the outside under flowing water conditions in the sewage treatment tank, or the carrier can flow out of the tank. It is possible to prevent problems such as clogging of the carrier with equipment such as a pump in the tank, and problems such as entanglement of fiber aggregates and decrease in fluidity.

  In particular, the sewage treatment tool in which the total volume of the sewage treatment microorganism carrier to be stored is 10 to 50% by volume with respect to the apparent volume of the capsule storage tool is suitable for the fiber assembly inside the capsule storage tool. It is more preferable because it provides a good movement, moderate contact with sewage, and retention of microorganisms, and improves sewage treatment capacity.

  As for the shape of the spherical lattice-shaped capsule container, it is preferable that fins are provided at least at a part of the inside of the frame constituting the spherical lattice. According to this configuration, the fin functions for water flow control, and a water flow in a certain direction flows into the capsule container under the water flow condition in the sewage treatment tank. As a result, the contact between the fibrous aggregate inside the capsule container and the sewage is improved, and the sewage treatment capacity is improved.

  According to the sewage treatment microorganism carrier of the present invention and the sewage treatment tool using the same, when used as a sewage treatment microorganism carrier that flows under flowing water conditions in a sewage treatment tank, small microorganisms such as bacteria are present. In addition to living uniformly inside the ball-shaped fiber assembly, a large number of relatively large protozoa such as earthworms can also inhabit, so the food chain system of microorganisms in the system functions and extremely high sewage treatment effect Demonstrate.

It is a figure which shows an example of the microorganisms support body for wastewater treatment of this invention. It is a figure which shows an example of the sewage treatment tool of this invention. It is a disassembled perspective view of the spherical lattice-shaped capsule storage device of the present invention. It is a front view of the spherical lattice-shaped capsule storage device of the present invention. It is sectional drawing of the flame | frame containing the fin of the spherical lattice-shaped capsule storage tool of this invention. It is a figure which shows the inside of the spherical lattice shape capsule storage tool of this invention.

  Hereinafter, one embodiment of a microorganism carrier for wastewater treatment and a wastewater treatment tool of the present invention will be described.

  FIG. 1 shows the appearance of a sewage treatment microorganism carrier 1 which is a preferred example of the sewage treatment microorganism carrier of the present invention. The microorganism carrier 1 is composed of a fiber assembly formed by bundling crimped fiber bundles. The fiber assembly constituting the microorganism carrier 1 has a structure in which a bundle of crimped fiber bundles is converged at both ends, and a central portion sandwiched between both converging portions is formed in a ball shape (substantially spherical). Hereinafter, the central ball-shaped portion is referred to as a “ball-shaped portion” and denoted by reference numeral “3”, and the converging portions formed at both ends of the ball-shaped portion 3 are referred to as “converging portions” and denoted by reference numeral “5”. " The diameter of the ball-shaped portion 3 is approximately 3 cm. The structure that converges the crimped fiber bundle is preferable because the fibers are not scattered or entangled under running water in the tank.

  The degree of crimp in the crimped fiber is preferably 5 to 40 times / 10 cm, the thickness of the fiber is preferably 0.03 to 0.2 mm in diameter, and the cross-sectional shape of the fiber is preferably circular, but is not limited to circular. Alternatively, an elliptical shape, a rectangular shape, a triangular shape, a hollow shape, or the like may be used. The specific gravity of the fiber is not limited, but 0.9 to 1.7 is preferable. The fineness varies depending on the specific gravity. For example, in the case of a fiber having a specific gravity of 1.7, 10d to 200d are preferable.

  Further, the porosity of the ball-shaped portion 3 of the fiber assembly is 90 to 99% by volume with respect to the apparent volume of the ball-shaped portion 3. If the porosity is less than 90% by volume, the purification efficiency per weight of the carrier decreases, and conversely if it exceeds 99% by volume, the ball-shaped portion 3 is not distorted and easily deforms, which is not suitable for practical use. Further, the apparent volume of the ball-shaped part 3 is the volume of a sphere that forms the outer shape of the ball-shaped part.

Furthermore, the average space | interval of each fiber of a ball-shaped part except a convergence part is 0.01-0.5. The average space | interval of fibers said here is a numerical value calculated | required from following formula (1).
Average interval = apparent volume of the ball-shaped portion 3 (cubic cm) × void ratio (%) of the ball-shaped portion 3 / total length of the fibers constituting the ball-shaped portion 3 (cm) (1)

The total fiber length referred to here is the sum of the lengths of all the fibers constituting the ball-shaped portion 3. The length of the fiber can be calculated from the following formula by measuring the weight of the fiber constituting the ball-shaped portion 3.
Fiber length (cm) = fiber weight (g) / fineness (denier) × 900000 cm
The fineness (denier) represents the weight (g) per 900,000 cm. Or when the cross section of a fiber is circular, you may calculate from the diameter and specific gravity of a fiber.

  In the ball-shaped part 3 having a porosity of 90 to 99% by volume, if the average interval is less than 0.01, the fibers become too dense, and large protozoa such as earthworms enter the ball-shaped part 3. The food chain system in the system cannot be established, and the sewage treatment capacity including sludge reduction cannot be demonstrated. Further, in the aeration tank, air generated by aeration does not reach the center of the ball-shaped portion 3, and the sewage treatment capacity is reduced.

  On the contrary, when the average interval exceeds 0.5, the interval between the fibers is excessively widened, and the active microorganism group that has settled on the fiber assembly due to the action and impact of the water flow under running water conditions in the sewage treatment tank Or protozoan groups such as earthworms fall out and the sewage treatment capacity is not demonstrated.

  When the average interval is 0.01 or more and 0.5 or less, not only microorganisms such as bacteria but also protozoa such as earthworms are generated, and the action of water flow under running water conditions in the sewage treatment tank, Even in the impact caused by the impact of the ball, the active microorganisms that have landed on the ball-shaped part 3 and the protozoan group such as earthworms do not fall off, and the sludge clinging to the surface of the ball-shaped part 3 is also appropriately screened, The contact property with water is improved, and in the aeration tank, air generated by aeration reaches the center of the ball-shaped portion 3 and the sewage treatment capability is dramatically improved.

  In particular, the average interval of 0.1 to 0.3 is more preferable because microorganisms such as bacteria and large protozoa such as earthworms are more likely to exist in a balanced manner. The average interval is more preferably 0.20 to 0.25.

As a method for converging the crimped fiber bundle, there are a method of heat-sealing by ultrasonic waves or high frequency, a method of converging by tightness of a plastic band or a metallic clip, and the like. Among them, as exemplified in FIG. 1, the binding with the aluminum wire 7 as seen in sausage or the like is preferable because it is easy to converge, has a strong convergence, and does not easily fall off the yarn, and is inexpensive. When the fiber assembly is converged, the convergence position may be at the center or at both ends.

  The number of fibers constituting one ball-shaped portion 3 is not particularly limited, but is usually composed of 100 to 10,000 crimped fibers. The type of fiber may be any synthetic fiber, and examples thereof include vinyl chloride, vinylidene chloride, polyamide, polyester, and polypropylene fiber. In particular, vinylidene chloride resin fibers are more preferable. The vinylidene chloride resin fiber referred to here is a polyvinylidene chloride fiber containing 80 to 99% by weight of a vinylidene chloride resin. When this fiber is used, the reason is unknown, but microorganisms such as bacteria It is more preferable because it is excellent in the implantation of protozoa such as earthworms and earthworms.

  The vinylidene chloride-based resin is obtained by polymerizing a monomer mixture including a vinylidene chloride monomer as a main component and at least one ethylene derivative monomer copolymerizable with the vinylidene chloride monomer. Here, “mainly” means that the vinylidene chloride monomer accounts for 70% by weight or more of the entire monomer mixture.

  Ethylene derivative monomers that may be included in the monomer mixture include nitriles of ethylenically unsaturated carboxylic acids such as acrylonitrile and methacrylonitrile, alkyl esters of acrylic acid and methacrylic acid such as methyl acrylate and methyl methacrylate, hydroxypropyl acrylate, Of hydroxyalkyl esters such as hydroxyethyl acrylate and hydroxybutyl acrylate, vinyl esters of saturated carboxylic acids such as vinyl acetate, amides of ethylenically unsaturated carboxylic acids such as acrylamide, ethylenically unsaturated carboxylic acids such as acrylic acid, allyl alcohol Examples thereof include ethylenically unsaturated alcohols and vinyl halides such as vinyl chloride. Among these, a vinyl chloride copolymer is superior in terms of fiber flexibility and durability, and is more preferable.

  Although the preferred weight ratio of vinylidene chloride monomer to ethylene derivative monomer in the monomer composition varies depending on the ethylene derivative monomer used, for example, when the ethylene derivative monomer is vinyl chloride, the preferred weight of vinylidene chloride monomer / vinyl chloride monomer The ratio is 70/30 or more and 98/2 or less. As the vinylidene chloride monomer obtained by setting the vinylidene chloride monomer to 70% by weight or more, crystallization is promoted, shrinkage of fibers is reduced, and dimensional stability is maintained, which is preferable. Conversely, the vinylidene chloride monomer content is preferably 98% by weight or less because the vinylidene chloride resin is not brittle and the strength is maintained, and the durability of the fiber assembly is further improved. More preferably, the weight ratio of vinylidene chloride monomer / vinyl chloride monomer is 80/20 or more and 95/5 or less.

  The sewage treatment microorganism carrier of the present invention is preferably stored in a capsule storage device. Therefore, the sewage treatment tool of the present invention comprises a capsule storage device and a microorganism carrier housed in the capsule storage device. As an example of the sewage treatment tool of the present invention, a sewage treatment tool 200 is shown in FIG. The sewage treatment tool 200 includes a capsule storage device 100 and a large number of microorganism carriers 1 stored in the capsule storage device 100.

  The capsule storage device 100 has a spherical lattice shape, and the size of the storage device is not particularly limited, but those having a diameter (outer diameter) in the range of 100 to 300 mm are usually used. Further, the gap of the lattice of the capsule container 100 is smaller than the diameter of the ball-shaped portion 3 of the microorganism carrier 1. Although details will be described later, instead of storing a large number of microorganism carriers 1, a microorganism carrier 107 forming a bead-like fiber aggregate may be stored in the capsule storage device 100 as shown in FIG. Good. The microorganism carrier 107 is obtained by connecting a plurality of microorganism carriers 1 in a daisy chain via the converging unit 5.

  For example, as shown in FIGS. 3 and 4, the capsule container 100 can be easily obtained by configuring the two hemispherical members 100 a by combining a pair of upper and lower parts. That is, if the two hemispherical members 100a are joined after the microorganism carrier is stored inside, the microorganism carrier can be stored in the capsule storage device 100 so as not to fall off. Methods for joining the hemispherical members 100a include fitting, banding, adhesive, ultrasonic fusion, thermal fusion, and the like.

  As an example, the capsule container 100 includes annular frames 101, 102, and 103 and a radial frame 104 as shown in FIG. The interval between the frames may be determined in consideration of the size and material of the storage tool, the size of the fiber assembly stored inside, and the like. Is about 4 to 8, the radial frames 104 are about 20 to 50, and the distance between the radial frames 104 is about 10 to 20 mm. Further, the shape of the radial frame 104 preferably has a rib shape on the inner side in terms of strength. The thickness and width of each frame are not particularly limited, but the thickness of each frame is usually preferably 2 to 5 mm. The material of the capsule container is not particularly limited, but polypropylene, polyethylene, nylon, and polyethylene terephthalate are preferable from the viewpoint of strength. Among these, polypropylene and polyethylene are more preferable because they are inexpensive. In particular, when using a polyvinylidene chloride fiber having a high specific gravity for the microorganism carrier housed inside, it is easy to appropriately adjust the overall specific gravity. It is even more preferable to use polypropylene.

  Furthermore, it is even more preferable that the capsule container has fins for water flow control at least at a part of the inside of the frame constituting the spherical lattice. The shape and size of the fin are not particularly limited. For example, as illustrated in FIGS. 3 and 5, the fin is formed as an integrally molded product from the radial frame 104 constituting the spherical lattice, and has a diameter toward the center. An example is a plate-like fin 105 extending about 1 to 2 cm in the direction.

  As the storage amount of the microorganism carrier to be stored in the capsule storage device, the apparent total volume of the microorganism support to be stored with respect to the apparent volume of the capsule storage device (for example, the volume of the sphere forming the outer shape of the capsule storage device 100). Is preferably 10 to 50% by volume. If the above value is 10% by volume or more, the microorganism-supporting performance per capsule is good and the cost performance is excellent. Moreover, when it is within 50% by volume, the fiber aggregate is easy to move inside the capsule container, and it is preferable that sludge is contained and hardly forms a nodule. More preferably, it is 15 to 30%.

  Moreover, it is preferable that the fiber assembly accommodated in the capsule storage device is a bead-like fiber assembly that includes a plurality of ball-shaped portions, and the plurality of ball-shaped portions are connected to each other via a converging portion. For example, as illustrated in FIG. 6, a plurality of microbial carriers 1 (see FIG. 1) are connected together via a converging unit 5 to form a rosary fiber aggregate 107, and the rosary fiber aggregate 107 is encapsulated. What is necessary is just to accommodate in the inside of the tool 100. FIG. Such a bead-like fiber assembly is preferable because it is difficult for the capsule storage device to fall off even under intense water flow under running water conditions in the sewage treatment tank. In the capsule storage device, one long chain of beaded fiber aggregates may be stored, or a plurality of short chain beaded fiber aggregates may be stored.

  Furthermore, it is more preferable that a part of these bead-like fiber aggregates is fixed to the capsule container because the bead-like fiber aggregates are more unlikely to fall out of the capsule container. Furthermore, for example, as shown in FIG. 6, it is preferable to fix both ends 108 of a plurality of bead-like fiber assemblies 107 to the frame of the capsule container 100. In this case, it is possible to prevent the bead-like fiber aggregates 107 from being entangled with each other due to a long-term flow, and the water treatment performance is improved.

  As a method for fixing the bead-like fiber aggregate to the capsule container, for example, as shown in FIG. 5, an opening 106 is provided in the inner fin 105 of the capsule container, and the bead-like fiber aggregate is formed in the opening 106. There is a method of fixing by inserting the end.

  The microorganism carrier for sewage treatment and the sewage treatment tool of the present invention are mainly used by being put into an aeration tank of an aerobic drainage treatment apparatus such as an activated sludge method to reduce sludge and improve the effluent water quality purification capability. Let Of course, it can also be used in an anaerobic tank of an anaerobic drainage treatment apparatus.

  In particular, in the sewage reclaimed water system, there is a sewage treatment device that combines an activated sludge tank and a membrane separation tank using a hollow fiber membrane, a reverse osmosis membrane, etc., and the sewage treatment of the present invention is applied to the activated sludge tank or the membrane separation tank. By using the microorganism carrier and the sewage treatment tool, the sludge is reduced, the load in membrane separation is reduced, the membrane performance is improved, the power consumption is reduced, and the membrane life is improved.

  The present invention will be described based on examples.

The measurement methods and conditions of physical properties used in the following examples are as follows.
1) Porosity (volume%)
The diameter of the ball-shaped part is measured with a caliper or the like, and the apparent volume A is calculated. By measuring the weight of the ball-shaped part and dividing by the specific gravity, the volume B of only the fiber is obtained.
The porosity is calculated from the following formula.
Porosity = (A−B) / A

2) Average spacing of fibers in the ball-shaped part.
Average interval = apparent volume of ball-shaped part (cm ³ ) × void ratio of ball-shaped part (%) / total length of fibers constituting ball-shaped part (cm) (1)

3) Water quality analysis after aeration and BOD (biochemical oxygen demand)
Measuring method: JIS K 0102: 2008
A water quality index that expresses the amount of organic matter in water as the amount of oxygen required by microorganisms for its oxidative degradation.
・ Total nitrogen Measurement method: Summation method The amount of total nitrides such as nitric acid, nitrous acid and ammonia in water.
・ Ammonia nitrogen Measurement method: Indophenol blue spectrophotometry Amount of ammonia in water.
・ SS (suspended substance concentration)
Measurement method: Japan Sewerage Association “Sewage test method” 1997
A water quality indicator that shows the turbidity of water in water by measuring the amount of suspended solids in the water.

[Example 1]
V-type vinylidene chloride-vinyl chloride copolymer resin consisting of 83 wt% vinylidene chloride monomer and 17 wt% vinyl chloride monomer, 5 wt% acetotributyl citrate as plasticizer, and 2 wt% epoxidized soybean oil as heat stabilizer After mixing with a blender to make a mixture, the mixture was melted with a 55 mmφ screw extruder, 3200 tow fibers were melt spun from a total of 3200 hole round hole nozzles, air-cooled, and then 2 with a speed difference roller. After being stretched twice, it was allowed to stand in a relaxed state without applying tension at room temperature for 10 minutes to give crimps, and 48,000 denier / 3200 filament (single yarn 15 denier) vinylidene chloride crimped fibers were obtained.

  The fibers were further bundled into three bundles to form tow-like fibers, which were then bound and cut with aluminum clips to obtain a fiber assembly having a ball-shaped portion with a diameter of 3 cm, which was bound with aluminum clips on both sides. In the ball-shaped portion of this fiber assembly, the porosity, apparent volume, total length of fibers, and average interval were as shown in Example 1 in Table 1. Using this fiber assembly, a wastewater treatment test was performed as follows.

As the wastewater treatment device, an activated sludge fluidization tank that sends aeration from the bottom of the tank was adopted. This tank has a volume of about 1.5m ³ (height 1.5m x width 1m x length 1m), and about 1m ³ of meat factory wastewater (raw water) is placed up to the height of 1m. I put it in. Next, 14,000 fiber assemblies having the above-mentioned ball-like portions (21% by volume of the apparent volume of the carrier with respect to the amount of drainage) were put in this aeration tank as a microorganism carrier for sewage treatment. In this treatment tank, an aeration process was performed for about 22 hours, and then half of the treated water was discharged and raw water was charged again. This was repeated for 60 days to attach microorganisms to the fiber assembly.

  The results of water quality analysis after the 60-day aeration treatment are shown in Example 1 of Table 1. From the results shown in Example 1 of Table 1, it was confirmed that the microorganism carrier for sewage treatment of the present invention was excellent in the purification action of sewage and had an excellent effect in reducing sludge.

[Example 2]
Using the same resin composition as in Example 1, 640 tow-like fibers were melt spun from a 640 hole round hole nozzle, air-cooled, stretched twice with a speed difference roller, and then tensioned at room temperature for 10 minutes. After being allowed to stand in a relaxed state without being subjected to crimping, 48,000 denier / 640 filament (single yarn 75 denier) vinylidene chloride crimped fiber was obtained.

  The fibers were further bundled into three bundles to form tow-like fibers, which were then bound and cut with aluminum clips to obtain a fiber assembly having a ball-shaped portion with a diameter of 3 cm, which was bound with aluminum clips on both sides. In the ball-like portion of this fiber assembly, the porosity, the apparent volume, the total length of the fibers, and the average interval as shown in Example 2 of Table 1 were obtained. Except for using this fiber assembly, the result of aeration treatment similar to that of Example 1 and water quality analysis after aeration treatment is shown in Example 2 of Table 1. From the results shown in Example 2 of Table 1, it was confirmed that the microorganism-supporting body for wastewater treatment of the present invention was excellent in the sewage purification action and excellent in reducing sludge.

[Example 3]
Using the same resin composition as in Example 1, 320 tow-like fibers were melt spun from a 320-hole round hole nozzle, air-cooled, stretched twice with a speed difference roller, and then tensioned at room temperature for 10 minutes. After being allowed to stand in a relaxed state without being subjected to crimping, 48,000 denier / 320 filament (single denier 150 denier) vinylidene chloride crimped fiber was obtained. The fibers were further bundled into three bundles to form tow-like fibers, which were then bound and cut with aluminum clips to obtain a fiber assembly having a ball-shaped portion with a diameter of 3 cm, which was bound with aluminum clips on both sides. In the ball-like portion of this fiber assembly, the porosity, the apparent volume, the total length of fibers, and the average interval as shown in Example 3 of Table 1 were obtained.

  Except for using this fiber assembly, the results of aeration treatment similar to that of Example 1 and water quality analysis after aeration treatment are shown in Example 3 of Table 1. From the results shown in Example 3 of Table 1, it was confirmed that the microorganism-supporting body for sewage treatment according to the present invention was very excellent in the purification action of sewage and had a very excellent effect in reducing sludge.

[Comparative Example 1]
The aeration treatment was performed in the same manner as in Example 1 except that the sewage treatment microorganism carrier was not added. As a result, from the results shown in Comparative Example 1 of Table 1, the purification effect of sewage was inferior compared with Examples 1-3.

[Comparative Example 2]
Using the same resin composition as in Example 1, 9600 tow-like fibers were melt spun from a total of 9600 hole round hole nozzles, air-cooled, stretched twice with a speed difference roller, and then at room temperature for 10 minutes. After allowing to stand in a relaxed state without applying tension and imparting crimps, 48,000 denier / 9600 filament (single yarn 5 denier) vinylidene chloride-based crimped fibers were obtained. The fibers were further bundled into three bundles to form tow-like fibers, which were then bound and cut with aluminum clips to obtain a fiber assembly having a ball-shaped portion with a diameter of 3 cm, which was bound with aluminum clips on both sides. In the ball-like portion of this fiber assembly, the porosity, apparent volume, total length of fibers, and average interval as shown in Comparative Example 2 of Table 1 were obtained.

  A comparative example 2 in Table 1 shows the results of performing the aeration process similar to Example 1 and performing the water quality analysis after the aeration process except that this fiber assembly is used. From the results shown in Comparative Example 2 of Table 1, the sewage treatment microorganism carrier of Comparative Example 2 was inferior in purification of sewage compared to Examples 1-3.

[Comparative Example 3]
Using the same resin composition as in Example 1, 96 tow fibers were melt spun from a total of 96 hole round hole nozzles, air-cooled, stretched twice with a speed difference roller, and then at room temperature for 10 minutes. After being allowed to stand in a relaxed state without applying tension and imparting crimps, 48,000 denier / 96 filament (single yarn 500 denier) vinylidene chloride-based crimped fibers were obtained. The fibers were further bundled into three bundles to form tow-like fibers, which were then bound and cut with aluminum clips to obtain a fiber assembly having a ball-shaped portion with a diameter of 3 cm, which was bound with aluminum clips on both sides. In the ball-like portion of this fiber assembly, the porosity, the apparent volume, the total length of fibers, and the average interval as shown in Comparative Example 3 of Table 1 were obtained.

  A comparative example 3 of Table 1 shows the results of performing the aeration treatment similar to Example 1 and performing the water quality analysis after the aeration treatment except that this fiber assembly is used. From the results shown in Comparative Example 3 of Table 1, the sewage treatment microorganism carrier of Comparative Example 3 was inferior in the sewage purification action compared to Examples 1-3.

[Comparative Example 4]
Using polypropylene resin, 240 tow-like fibers were melt spun from a total of 240 hole round hole nozzles, air-cooled, stretched twice with a speed difference roller, and then relaxed without applying tension for 10 minutes at room temperature. After being allowed to stand for crimping, a 48,000 denier / 240 filament (single yarn 200 denier) polypropylene crimped fiber was obtained. The fibers were further bundled into three bundles to form tow-like fibers, which were then bound and cut with aluminum clips to obtain a fiber assembly having a ball-shaped portion with a diameter of 3 cm, which was bound with aluminum clips on both sides. In the ball-like portion of this fiber assembly, the porosity, apparent volume, total length of fibers, and average interval were as shown in Comparative Example 4 in Table 1.

  A comparative example 4 in Table 1 shows the results of performing the aeration treatment similar to that in Example 1 and performing the water quality analysis after the aeration treatment except that this fiber assembly is used. From the results shown in Comparative Example 4 of Table 1, the sewage treatment microorganism carrier of Comparative Example 4 was inferior in the sewage purification action compared to Examples 1-3.

[Comparative Example 5]
Using polyethylene terephthalate resin, 12000 tow-like fibers were melt spun from a total of 12000 holes round hole, air-cooled, stretched twice with a speed difference roller, and then relaxed without applying tension for 10 minutes at room temperature. After leaving in the state to give crimps, 48,000 denier / 12000 filament (single yarn 4 denier) polyethylene terephthalate crimped fiber was obtained.

  The fibers were further bundled into three bundles to form tow-like fibers, which were then bound and cut with aluminum clips to obtain a fiber assembly having a ball-shaped portion with a diameter of 3 cm, which was bound with aluminum clips on both sides. In the ball-like portion of this fiber assembly, the porosity, the apparent volume, the total length of fibers, and the average interval as shown in Comparative Example 5 of Table 1 were obtained.

  A comparative example 5 in Table 1 shows the results of performing the aeration treatment similar to Example 1 and performing the water quality analysis after the aeration treatment except that this fiber assembly is used. From the results shown in Comparative Example 5 of Table 1, the sewage treatment microorganism carrier of Comparative Example 5 was inferior in purification of sewage compared to Examples 1-3.

[Example 4]
2 to 5 capsule assembly (made of polypropylene, 20 cm in diameter), 60 fiber assemblies having a ball-like portion having a diameter of 3 cm as in Example 3 (relative to the apparent capsule volume) A sewage treatment tool was prepared in which the total apparent volume of the balls was 20% by volume).

As the wastewater treatment equipment, an aeration recirculation activated sludge tank was adopted, but this tank has a volume of about 4.5 m ³ (height 1.5 m × width 1 m × length 3 m). About 3m ³ of food factory effluent (raw water) was thrown up to 1m. Next, 150 pieces of the above-mentioned sewage treatment tools (capsules) (the apparent volume ratio of the carrier was 21% by volume with respect to the amount of drainage) were put into this aeration tank. In this treatment tank, a cycle in which aeration treatment is carried out for about 20 hours, aeration is stopped for 2 hours to precipitate, half of the 1.5 m ³ supernatant is discharged, and then about 1.5 m ³ of the food factory wastewater is charged again. Repeated for about 3 months, and waited for bacteria and protozoa to stably land on the carrier.

  Table 2 shows the results of water quality analysis of food factory effluent (raw water) and discharged water after aeration after 3 months from loading the support. (However, for SS, treated water before settling was collected immediately after the end of aeration rather than discharged water.) At the same time, the sewage treatment tool was collected and the internal state was confirmed. Implantation of protozoa such as earthworms was observed, and it was confirmed that it is excellent not only for bacteria but also for implantation of protozoa.

  From the results shown in Example 4 in Table 2, the microorganism carrier for sewage treatment and the sewage treatment tool of the present invention are very excellent in the sewage purification action and also have a very excellent effect in reducing sludge. confirmed.

[Comparative Example 6]
An aeration treatment experiment similar to that in Example 4 was performed, except that the sewage treatment microorganism carrier was not added. As a result, from the results shown in Comparative Example 4 in Table 2, the purification action of sewage was inferior compared with Example 4.

  The microorganism carrier for sewage treatment according to the present invention does not require any special remodeling work or the like for the existing activated sludge tank, and can greatly improve the drainage treatment capacity by simply introducing it.

  Moreover, in the sewage reclaimed water system using the membrane separation tank, by using the sewage treatment microorganism carrier of the present invention, sludge is reduced, the load in membrane separation is reduced, the membrane performance is improved, and the power consumption is increased. Can be reduced and the useful life of the membrane can be improved.

DESCRIPTION OF SYMBOLS 1 Microbe support body for wastewater treatment 3 Ball-shaped part 5 Focusing part 100 Capsule container 101 Annular frame (large)
102 Ring frame (middle)
103 Ring frame (small)
104 Radial frame 105 Fin 106 Fin opening 107 Beaded fiber aggregate 108 Fixed end part 200 of beaded fiber aggregate Sewage treatment tool

Claims (5)

A microorganism-supporting body for wastewater treatment comprising a fiber assembly in which fibers are assembled,
The fiber assembly includes a ball-shaped portion having a ball shape and a converging portion that is formed at an end of the ball-shaped portion and focuses the fibers.
The void ratio of the ball-shaped part is 90 to 99% by volume with respect to the apparent volume of the ball-shaped part,
A microorganism-supporting body for sewage treatment in which an average interval represented by the following formula (1) of fibers constituting the ball-shaped portion is 0.01 to 0.5.
Average interval = apparent volume of ball-shaped part (cubic cm) × porosity of ball-shaped part (volume%) / total length of fibers constituting ball-shaped part (cm) (1)   The microorganism carrier for sewage treatment according to claim 1, wherein the fibers constituting the fiber assembly are polyvinylidene chloride fibers containing 80 to 99% by weight of vinylidene chloride resin.   The sewage according to claim 1 or 2, wherein the fiber aggregate is a rosary fiber aggregate that includes a plurality of the ball-shaped portions, and the plurality of ball-shaped portions are connected to each other via the converging portion. Microorganism carrier for treatment. The sewage treatment microorganism carrier according to any one of claims 1 to 3, and a spherical lattice-shaped capsule container for housing the sewage treatment microorganism carrier,
The sewage treatment tool, wherein the apparent total volume of the sewage treatment microorganism carrier to be stored is 10 to 50% by volume with respect to the apparent volume of the capsule storage tool.   The sewage treatment tool according to claim 4, wherein the spherical lattice-shaped capsule storage device has fins on at least a part of an inner side of a frame constituting the spherical lattice.

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