JP2538787B2 - Microorganism immobilization carrier - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a microorganism-immobilized carrier having an artificial fiber as a main component, and more specifically, a porous sheet having an artificial fiber as a main component. TECHNICAL FIELD The present invention relates to an adsorptive microorganism-immobilized carrier used as a bioreactor by immobilizing microorganisms in the pores of a solid or three-dimensional molded article.

(Prior Art and Problems Thereof) Conventionally, adsorption-type microorganism-immobilized carriers have been mainly used in the field of water treatment, and also widely used in the field of fermentation for producing alcohol (liquor) or vinegar.

Such microorganisms-immobilized carriers include plastic flat plates, corrugated plates, mesh plates, tubes, three-dimensional mesh products, string-shaped products and molded granules, or biscuit plates, crushed stones, asbestos plates (flat plates, corrugated plates, etc.), BACKGROUND ART Ceramic granules and three-dimensional molded products (for example, saddle-shaped products, macaroni-shaped products, honeycomb-shaped products, etc.) are known.

(Problems to be Solved by the Present Invention) However, each of these conventional techniques has advantages and disadvantages and is not sufficiently satisfactory. That is, although conventional plastics have the advantages of being durable, easy to process, lightweight, and inexpensive, the immobilization of microorganisms is unstable and the microorganism membrane layer suddenly falls off, immobilizing microorganisms. As a carrier, there were drawbacks related to basic performance.

On the other hand, ceramic materials such as unglazed plates are better in fixing microorganisms than plastic ones, but it is difficult to control the pores that fix the microorganisms, so the pores are easily blocked by the microorganisms and the microorganisms are stably immobilized. Difficult, heavy, difficult to make large area plate, expensive, shape,
There were drawbacks such as size restrictions. Furthermore, asbestos board is originally used for wall materials, roofing materials, etc. for non-combustible building materials, but the main component is asbestos, and it has the drawback that it is in the direction of avoiding use due to pollution problems. .

(Means for Solving Problems) The inventors of the present invention have conducted extensive studies to eliminate the drawbacks of the conventional techniques, and as a result, have an excellent adsorbability of microorganisms on the surface having a surface tension of 40 dynes / cm or more. However, in the state of monofilaments is not enough to stably immobilize microorganisms, and it has been found that the present invention can be an excellent microorganism-immobilized carrier by using a porous carrier. is there.

That is, the present invention is mainly composed of an artificial fibrous material, the surface tension of the porous sheet-like or three-dimensional molded article formed by using a binding means is 40 dynes / cm or more immobilization of microorganisms characterized by Regarding the carrier.

More specifically, a man-made fibrous material, preferably a porous sheet-like or three-dimensional molded article whose main component is a man-made fibrous material having a surface tension of 40 dynes / cm or more, and is molded or molded. After that, the present invention relates to a microorganism-immobilized carrier, wherein the surface tension of the molded product is finally adjusted to 40 dynes / cm or more by surface treatment if necessary.

The artificial fiber used in the present invention has an average fiber diameter of 0.
1 to 30 μm and an average fiber length of 100 μm or more, but a surface tension of 40 dyne / cm or more is preferable,
Artificial fibrous materials satisfying this condition are classified into artificial inorganic fibers and artificial organic fibers as shown below.

Such artificial mineral fibers include glass fibers, micro glass fibers, alumina silica fibers, alumina fibers, mullite fibers, zirconia fibers, quartz fibers,
Highly silicic acid fibers, boron fibers, rock wool, mineral wool, potassium titanate fibers, phosphate fibers, borosilicate fibers, carbon fibers, artificial inorganic fibers having a surface tension of 40 dynes / cm or more such as activated carbon fibers are exemplified. However, the present invention is not limited to these.

On the other hand, artificial organic fibers have a surface tension of 40
Polyamide fibers (nylon 66, nylon 6, etc.), polyester fibers, etc. are exemplified as those satisfying dyne / cm or more, but those having less than 40 dyne / cm are single fibers by surface treatment or internal addition treatment. In this state, the surface tension can be increased to 40 dyne / cm or more.

Examples of the treatment method include corona discharge treatment, plasma jet treatment, plasma polymerization treatment, ion beam treatment, ultraviolet treatment, laser treatment, chemical treatment, coupling agent treatment, vapor deposition treatment, ion plating treatment, sputtering treatment, Examples of the treatment include surface treatments such as encapsulation treatment, coating treatment, plating treatment, spray treatment, and internal addition treatment of a surface tension modifier (inorganic powder etc.), but are not particularly limited thereto.

If the surface tension of the fiber is made to be 40 dynes / cm or more by such a treatment, in addition to the polyester type and polyamide type, polyolefin type (polyethylene, polypropylene etc.), aromatic polyamide type (aramid etc.), polystyrene type poly Acrylic (polyacrylonitrile, etc.),
Artificial organic fibers such as acetate fibers, PVA fibers (vinylon, polyclar, PVA, etc.) and rayon fibers can also be preferably used.

In addition, using only artificial organic fibers having a surface tension of less than 40 dynes / cm, or using 1 part together to form a porous sheet-like or three-dimensional object, the same surface treatment as the above-mentioned single fiber is performed. Although it is possible to achieve the object of the present invention even after the final surface treatment by the method to 40 dyne / cm or more, the surface tension is 40 dyne / cm or more using an artificial fibrous material, the porous carrier layer inside It is more preferable because microorganisms are easily adsorbed on the fiber surface.

Furthermore, artificial tension fibers having a surface tension of less than 40 dynes / cm are used in combination with artificial fibrous substances having a surface tension of 40 dynes / cm to form a porous carrier, and then used as a carrier without surface treatment. If so, considering the blending ratio of the artificial fibrous material used, the surface tension of the artificial fibrous material is an average value of 40 dynes / cm, preferably 50 dynes / cm or more,
It exhibits superior performance over prior art carriers.

Since these artificial fibrous materials are manufactured artificially, the average fiber diameter is relatively uniform, and the average fiber length can be made uniform to some extent, and when forming into a porous carrier, microorganisms are fixed. It is relatively easy to control the size of the pores. Further, since it is fibrous, the surface area for adsorbing microorganisms can be increased.

In addition, the cross-sectional shape of artificial fibrous material is very large, circular,
Examples thereof include an oval shape, a belt shape, an eyebrow shape, a hollow shape, and a star-shaped indefinite shape, but the present invention is not limited to these sectional shapes.

The surface condition of the artificial fibrous material is not particularly limited, but a porous or rough surface is preferable from the viewpoint of adsorbing microorganisms.

One or more of the artificial fibrous materials as described above are selected and molded into a porous sheet-like or three-dimensional material to be used as a microorganism-immobilized carrier. From the viewpoint of durability, it is more preferable to use the artificial inorganic fiber and the artificial organic fiber together. The artificial inorganic fiber is less likely to be swollen by a solution and has durability against microorganisms. In this respect, it is preferably used as compared with the artificial organic fiber, but when it is a porous carrier having a complicated shape, it is molded. Since it is difficult to use, it can be preferably used in combination with the artificial organic fiber. The blending ratio is preferably 0 to 80% of artificial organic fiber to 100 to 20% by weight of artificial inorganic fiber in view of the above-mentioned moldability and durability.

Further, in addition to the artificial fibrous material as a main component, a powdery material, preferably an inorganic powdery material having a surface tension of 40 dynes / cm or more may be used in combination if desired. Examples of such a powdery material include silica stone, silica sand, diatomaceous earth, kibushi clay, frog clay, kaolin, halloysite, montmorillonite, bauxite, bentonite, zeolite, phosphate rock, diaspore, gypsite, peat moss, clay Mica (serisite, illite), vermiki, ulite,
Natural minerals such as acid clay, pottery stone, wax stone, feldspar, limestone, wollastonite, plaster, dolomite, magnesite, talc, mountain hide (α sepiolite, β sepiolite, attapulgite, palygorskite), silas balloon, or hydroxide. Of various oxides such as aluminum, magnesium hydroxide, ferric hydroxide and other metal oxides, calcium silicate hydrates such as tvermonite and xonotlite, calcium aluminate hydrates and calcium sulfaluminate hydrates Hydrate, alumina, silica, magnesia, zirconia, doria, beryllia, titanium oxide, spinel, synthetic zeolite, synthetic calcium carbonate, calcium phosphate, various carbides (TiC, ZuC, BaC, SiC, etc.), various nitrides (TN, BN) and Si ₂ N _3), synthetic mica (sodium tetra silicilytes bear squid, sodium or lithium Muteniolite, sodium or lithium hectorite), metal titanate (potassium titanate, calcium titanate, sodium titanate, beryllium titanate, strontium titanate, magnesium titanate, etc.), graphite, activated carbon, artificial carbon black, etc. Examples include powders of inorganic substances, fine fibrous substances having a length of less than 100 μm, and whiskers, scales, and flakes. Since the role of these powdery substances is mainly to adjust the surface tension and the size of the pores, it is desirable that the combined amount thereof is approximately 30% by weight or less with respect to the artificial fibrous substance. If the amount of the powdery substance is too much, the pores become small, and inconvenience occurs in durability and the like.

A binder component may be used when molding these porous sheet-shaped or three-dimensional molded products, and examples of the binder component include heat-fusible fibers, alumina sol,
Examples include inorganic substances such as silica sol, emulsions or organic solvent solutions of thermoplastic resins, latexes or organic solvent solutions of synthetic rubber, emulsions or organic solvent solutions of thermally crosslinkable resins.

The binder component is not particularly limited, among binders showing suitable adhesiveness to the artificial fibrous material used according to the molding method, preferably the surface tension after film formation is 40 dynes / cm. The above items are properly selected and used. The blending ratio (solid content) of the binder component is preferably about 30% by weight or less, preferably 20% by weight or less, to the extent that the binder component does not impair the surface condition of the artificial fibrous material. More preferably, a heat-fusible fibrous material having a heat-fusible property as a binder component can be bound without covering the surface of the artificial fibrous material which is the main component of the present invention, and thus is preferably used. As the heat-fusible component, one having a heat-melting temperature lower than the heat-melting temperature of the artificial fibrous material to be used and not impairing the fiber morphology of the artificial fibrous material is used.

Further, other paper-making agents (for example, organic polymer flocculant, vanadium sulfate, sodium aluminate, etc.) may be used.

Next, as a method for molding the porous sheet-like or three-dimensional object in the present invention, a wet papermaking method or a method similar thereto, or a spunbond method, a needle punch method, a stitch bond method, a tufted method, electric flocking. Examples of the dry non-woven fabric manufacturing method include, but the present invention is not limited thereto.

Among them, the wet papermaking method or a method similar thereto is a powdery material,
It is particularly preferable because it has good formability without breaking fibrous materials, easy control of pores, high productivity, and light weight and large area can be manufactured at low cost.

The wet papermaking method or a method similar thereto means that a part or all of the components of the molded product are made into an aqueous dispersion, and then, for example, a belt-shaped, cylindrical, rectangular, etc. filter net, a filter cloth or a filter plate is used. A general term for a method of forming a molded product by allowing the aqueous dispersion to flow over a different filtration medium, or after sandwiching between these filtration media, and then filtering and drying by an operation such as natural filtration or vacuum filtration. is there.

If desired, the sheet-shaped or three-dimensional molded product thus obtained may further include an inorganic material such as alumina sol or silica sol, an emulsion or organic solvent solution of a thermoplastic resin, a latex or organic solvent solution of synthetic rubber, or an emulsion of a heat-crosslinkable resin. A binding component such as an organic solvent solution is used to the extent that the surface condition of the artificial fibrous material is not impaired, and the solid content is generally 30% by weight or less, preferably 20% by weight or less, and impregnated or coated to reinforce. Good.

Furthermore, the sheet-like material can be secondarily processed into a honeycomb process, a corrugated process, or another three-dimensional shape.

As described above, before or after molding, so that the surface tension of the final porous sheet-like or three-dimensional molded article becomes 40 dynes / cm, the above-mentioned surface treatment, if necessary. To obtain a microorganism-immobilized carrier having a surface tension of 40 dynes / cm or more.

Furthermore, the surface tension obtained as described above is 40 dynes / c.
It is also possible to use these sheet-like or three-dimensional structures having a size of m or more further by heat-sealing or adhering to the surface of a polyvinyl chloride, polyethylene, polypropylene, polyester resin plate or the like with an adhesive or the like to form a composite.

Furthermore, these sheet-like or three-dimensional structures can be used by sandwiching or wrapping them in a plastic net having a large mesh.

Which of these methods is adopted may be appropriately selected and used depending on the purpose of use of the bioreactor on which the microorganism is immobilized, the method of use, etc., and is not limited to the exemplified method.

The porous sheet-shaped molded product and three-dimensional molded product constituting the carrier of the present invention obtained as described above have an average pore diameter of 0.1 to 300 μm, and more preferably 1 to 10 μm.
The range of 0 μm is preferable.

That is, an average pore size of less than 0.1 μm is too small to cause immobilization of microorganisms, and an average pore size of more than 300 μm is too large, for example, by aeration under aerobic conditions or by stirring or flowing of a substrate. , The microorganisms adsorbed on the carrier are easy to fall off,
Is unsuitable as Since the pores are the home of microorganisms,
It is closely related to the size of the microorganism itself, and it is not preferable that the size of the microorganism is too large or too small, and an appropriate size is required. To control the size of the pores, for example, when making large pores, the average fiber diameter should be large, and fibers having a long average fiber length should be used as the main component. A fiber having a small fiber diameter and a short average fiber length may be mainly used, and if necessary, a fine fibrous substance, a whisker-shaped substance, or a powdered substance may be used in combination.

Further, a larger surface area is more convenient for immobilization of microorganisms in order to increase the contact surface with the microorganisms. If the surface tension is 40 dynes / cm or more as the specific surface area, 0.5 m ² / g or more is suitable.

(Effects of the Invention) The microorganism-immobilized carrier formed into a porous sheet-shaped or three-dimensional shaped article of the present invention has an artificial fibrous material having a surface tension of 40 dynes / cm or more as a main component, or is surface-treated. As a result, the final surface tension of the carrier is 40 dynes / cm or more, and it is easy to control the pores of a size suitable for microorganisms, so the microorganisms adsorbed on the fiber surface are stable in the pores of the carrier. Since it can be immobilized by the method, and a large-area carrier can be produced without being restricted by the shape and size, it can be suitably used as a bioreactor.

The microorganism-immobilized carrier according to the present invention is domestic human waste and household wastewater treatment, agricultural settlement wastewater treatment, sewage pretreatment, organic matter processing plant wastewater treatment, water supply treatment, aquatic animal breeding water treatment,
Not only effective utilization for a wide range of water treatment facilities such as water treatment for aquatic plant cultivation, but also fermentation fields such as alcohol, soy sauce, vinegar, etc., further field for culturing animal and plant cells, decomposition and deodorization of odorous gases by microorganisms, etc. Can be effectively used in a wide range of.

(Examples) Next, the present invention will be specifically described with reference to examples, but the present invention is not limited to the following examples.

In the present invention, the average pore diameter was measured by the mercury porosimetry method.

For those with unknown surface tension, formamide (58 dynes / cm), a solvent with known surface tension, and ethyl cellosolve (3
0 dynes / cm), cyclohexane (25 dynes / cm), etc., and measured between 30-58 dynes / cm using a dyne test solution (commercially available) with different mixing ratios of formamide and ethyl cellosolve did. The fibrous material was judged by immersing the fiber in the dyne test solution and remaining in a bead shape on the fiber surface when the fiber was taken out or diffusing. If it becomes a sphere, it means that the surface tension of the fibrous material is smaller than the surface tension of the test liquid, and if it is diffused, it means that it is equal to or higher than the surface tension of the test liquid.

 The specific surface area was measured by the BET method.

Example 1 and Comparative Example 1 Polyethylene fiber (average fiber diameter 18
μm, surface tension 31 dynes / cm) cut to an average fiber length of 5 mm, using polyvinylidene chloride emulsion (surface tension 40 dynes / cm in film form) as a binder component to form sheets by wet papermaking. The adhered amount of the binder component was 20% by weight (solid content). The thickness of this sheet is 0.5 mm and the average pore size is 35 μm.
Met. The surface tension of this sheet-like material was 33 dyne / cm when measured with a dyne test solution. When the surface tension of this sheet-like material was similarly measured after subjecting it to corona discharge treatment, it was 46 dynes / cm.

The sheet-like material subjected to corona discharge treatment was attached to both sides of a polyvinyl chloride plate having a thickness of 2 mm with a nitrile rubber adhesive to give a test sample (Example 1). Separately, a sheet-shaped material not subjected to corona treatment was also attached as a test sample (Comparative Example 1) by the same method.

Each of these test samples was set as a contact material in the contact aeration tank of the small experimental septic tank shown in Fig. 1,
Under the following experimental conditions, the same seed sludge (containing microorganisms) was inoculated while a certain amount of artificial sewage was flowed to immobilize the microorganisms on the surface of the contact material and compare the purification performance of BOD (biochemical oxygen demand) removal under the following conditions. Tested

Experimental conditions 1) Artificial sewage: Using the glucose glutamic acid mixed standard solution according to JIS K0102 as artificial sewage (BOD220ppm) 2) Artificial sewage supply rate ...... 2L / 2L tank / day 3) Aeration rate ...... 2L (Air) / 2L (Wed) ・ hr 4) Surface of contact material …… 2400cm ² / 2L tank 5) Rotation speed of carrier sheet …… 6rpm 6） Sampling of discharged water …… 15 days after the start of treatment 7) Seed sludge …… Sewage collected from nearby sewage is artificial sewage I used the one that was used for a month.

The results of the above comparative tests are shown in Table-1.

As is clear from the results in Table-1, the polyethylene fiber sheet was subjected to corona discharge treatment and the surface tension was changed from 33 dyne / cm to 46 dyne / cm.
The BOD removal effect was significantly higher when modified to dyne / cm.

Examples 2 to 3 and Comparative Example 2 As an artificial fibrous material, polyclar fiber (average fiber diameter 15
μm, average fiber length 5 mm, surface tension 38 dyne / cm) and alumina silica fiber (average fiber diameter 2.8 μm, average fiber length 5 mm, surface tension 58 dyne / cm or more) are mixed and used, as shown in Table-2. Sheets were formed by a wet papermaking method at various ratios.
At that time, as a binder component, heat-fusible vinylon fiber (Kuraray Co., Ltd., Kuraray VPB105-1 × 3: surface A tension of 38 dynes / cm and a heat melting temperature of 70 ° C.) were used, and heat fusion was performed by heat during drying. At this time, the weight of the sheet is 100 g /
It was adjusted to m ² and thickness of 0.3 mm. The results of the same tests as in Example 1 are shown in Table-2.

As is clear from the results in Table 2, the BOD removal capacity increased as the ratio of the ceramic fibers having a high surface tension and a large specific surface area increased.

Example 4 The sheet-shaped material of Comparative Example 2 was used and silica was applied to the surface of 800
Making a vacuum-deposited sheet with a thick Angstrom,
Table 3 shows the results of the same experiment as in Example 1.

Comparing the results with Comparative Example 2, it is clear that Example 4 in which the surface treatment is performed with silica and the surface tension is increased has a higher BOD removing ability.

Examples 5-6 Polyester fiber (average fiber as artificial fiber) 90% by weight of a fiber having a fiber diameter of 8 μm and a surface tension of 42 dynes / cm) cut to an average fiber length of 5 mm was used in the same manner as in Example 2, and a heat-fusible vinylon fiber (Kuraray VPB1) was used as a binder component.
(05-1 × 3: surface tension 38 dynes / cm) was used to form a sheet by a wet papermaking method using 10% by weight. At this time, the sheet has a basis weight of 10
The thickness was adjusted to 0 g / m ² and the thickness was 0.3 mm (used in Example 5). Furthermore, a paint in which titanium oxide fine powder having an average particle diameter of 0.1 μm (surface tension of 58 dynes / cm or more) is dispersed in polyvinylidene chloride emulsion (surface tension after film formation is 40 dynes / cm) (solid content ratio: Titanium oxide / vinylidene chloride = 2 /
1) was impregnated with 15% by weight (solid content ratio) and dried (used in Example 6). These sheet samples were tested by the same test method as in Example 1. The results are shown in Table-4.

As is clear from the results shown in Table 4, in the case of Example 5, it is recognized that the BOD removal performance is excellent as compared with Comparative Examples 1 and 2, but in the case of Example 6, the BOD removal performance is higher. became.

Example 7 As an artificial fibrous material, 30% by weight of finely powdered silica (average particle diameter 0.2 μm) was kneaded in a polyethylene resin to give an average fiber diameter of 1
A polyethylene fiber having a size of 8 μm was produced. The surface tension of this fiber was 46 dynes / cm. This fiber was cut into an average fiber length of 5 mm and molded into a sheet by the same method as in Example 1 except that the corona discharge treatment was not performed. The thickness of this sheet was 0.5 mm, and the average pore diameter was 35 μm. The surface tension of this sheet-like material was 45 dyne / cm as measured with a dyne test solution. The results of the BOD removal performance test conducted on this sheet by the same method as in Example 1 are shown in Table-5.

As is clear from the results in Table 5, Example 7 in which silica was internally added showed a markedly improved BOD removal effect as compared with Comparative Example 1 in which silica was not internally added.

Example 8 and Comparative Example 3 As artificial fibrous material, extra fine PVA fiber (average fiber diameter 0.3 μm)
m, surface tension 38 dynes / cm) cut into an average fiber length of 5 mm, 80% by weight and insoluble vinylon fibers (average fiber diameter)
10 μ% of 13 μm, surface tension 37 dyne / cm) cut to an average fiber length of 5 mm, and heat-fusible vinylon fiber (Kuraray VPB105-1 × 3: surface tension 38 dyne) as a binder component.
/ cm) 10% by weight to form an aqueous dispersion, which was formed into a sheet by a wet papermaking method. At this time, the basis weight of the sheet is 100 g / m
^2. Thickness was 0.25 mm and surface tension was 38 dynes / cm (used as Comparative Example 3).

On the other hand, 80% by weight of ultrafine micro glass wool (average fiber diameter 0.3 μm, average fiber length 5 mm, surface tension 48 dyne / cm) and insoluble vinylon fiber (average fiber diameter 1
3 μm, average fiber length 5 mm, surface tension 37 dynes / cm) 10% by weight, 10 parts by weight of heat-fusible vinylon fibers (Kuraray VPB105-1 × 3: surface tension 38 dynes / cm) as a binder component are mixed and dispersed in water. It was formed into a sheet by the same wet papermaking method as the body (used as Example 8). At this time, the basis weight of the sheet was 100 g / m ² , the thickness was 0.22 mm, and the surface tension was 45 dynes / cm.

Each of these sheets was adhered to both sides of a 2 mm-thick polyvinyl chloride plate with a nitrile rubber-based adhesive, and the BOD removal performance under anaerobic conditions was compared under the following experimental conditions by a device as shown in FIG. The results are shown in Table-6.

Experimental conditions 1) Artificial sewage …… Uses glucose glutamic acid mixed standard solution according to JIS K0102 as artificial sewage (BOD 220ppm) 2) Artificial sewage supply rate …… 2L / 2L tank / day 3) Contact material surface …… 2400cm ² / 2L tank 4) Rotational speed of carrier sheet …… 6rpm 5) Sampling of discharged water …… 30 days after the start of treatment 6) Seed sludge …… The bottom sludge is collected from nearby sewage, It was used for one month in artificial sewage.

As is clear from the results in Table-6, the BOD removing ability of Example 8 was significantly higher than that of Comparative Example 3 even under anaerobic conditions.

Example 9 Micro glass fiber (average fiber diameter) as an artificial fiber material
0.8 μm, average fiber length 5 mm, surface tension 48 dynes / cm) 40% by weight, polyester fibers (average fiber diameter 8 μm, average fiber length 5 mm, surface tension 42 dynes / cm) 29% by weight, diatomaceous earth as an inorganic powder ( Celite R680: Manville (US)
Made, surface tension 58 dynes / cm or more, average pore diameter 1.8 μm) 20
Wt%, heat-fusible polyethylene fiber as binder component (Mitsui Petrochemical, SWPE-400: surface tension 31 dyne / c
m, heat melting temperature 138 ° C) 10% by weight and polyamide / polyamine epichlorohydrin resin 1.0% by weight (solid content) to form an aqueous dispersion, and a basis weight of 150 g using a Fourdrinier paper machine, which is a type of wet papermaking method. It was formed into a sheet-like material having a thickness of 0.38 mm / m ² . The surface tension of this sheet material is 52 dynes / cm,
The average pore diameter was 8 μm and the specific surface area was 24.5 m ² / g. This sheet material is stepped with a corrugating machine at a wave height of 10 mm, and the same sheet material is used as liner paper on both sides of the sheet material with nitrile rubber adhesive as shown in Figure 3. A corrugated product was obtained. The corrugated product thus obtained was set as a microorganism-immobilized carrier in a small-sized combined septic tank for home use, and a treatment test of human waste and waste water discharged from the home was conducted. The flow sheet and processing conditions for the small household combined septic tank are as follows.

Raw water flow rate: 250 L / L / day (5-person tank) Aeration amount: 2.0 m ³ (air) / m ³ (water) / hour Anaerobic filter bed tank (2nd chamber): 1.3 m ³ Contact aeration tank Volume: 1.2m ³ Contact material size: 750mm x 1200mm Number of contact materials used: 14 anaerobic filter bed second chamber 14 contact aeration tanks Processing time: Installation 6 months later Table 7 shows the results of daily water quality changes from 6:00 am to 24:00 pm.

As is clear from the results in Table-7, the BOD is stable at 10PPM or less all day long, and the BOD emission design value of 20PPM or less of the small combined septic tank is cleared with sufficient margin, which is very excellent. It exhibited excellent performance.

In addition, the amount of suspended solids (SS) also showed a stable low value, demonstrating excellent performance as a small-scale combined septic tank for home use.

[Brief description of drawings]

FIG. 1 is a schematic view of small experimental septic tanks used for performance tests under aerobic conditions in Examples 1 to 7 and Comparative Examples 1 and 2. a: 2L tank b: Carrier sheet c: Air diffuser A: Artificial sewage B: Discharged water Figure 2 is a schematic diagram of a small experimental septic tank used for performance tests under anaerobic conditions in Example 8 and Comparative Example 3. Is. FIG. 3 is a schematic view of a corrugated porous carrier of the present invention.

Continuation of front page (56) Reference JP-A-52-89239 (JP, A) JP-A-64-34492 (JP, A) JP-A-62-91292 (JP, A)

Claims (5)

(57) [Claims] 1. A microorganism-immobilized carrier characterized in that the surface tension of a porous sheet-like or three-dimensional molded article containing an artificial fibrous material as a main component is 40 dynes / cm or more. 2. The microorganism-immobilized carrier according to claim 1, wherein the surface tension of the artificial fibrous material is 40 dynes / cm or more. 3. An artificial fibrous material as a main component, which is molded by using a binder component.
The microorganism-immobilized carrier according to the item. 4. The microorganism-immobilized carrier according to claim 3, wherein a heat-fusible fibrous material is used as a binder component. 5. The microorganism-immobilized carrier according to claim 1, wherein the sheet-shaped molded product is molded by a wet papermaking method or a method similar thereto.