JP7412240B2 - Gas supplies, supply units, systems, and wastewater treatment equipment - Google Patents

Description

This invention relates to a wastewater treatment device that utilizes the action of aerobic microorganisms to decompose organic matter in water and purify wastewater.

Aerobic microbial wastewater treatment devices are widely used as a method for treating organic wastewater. On the other hand, aeration using a diffuser tube has low oxygen dissolution efficiency and requires aeration at a pressure higher than the water pressure applied to the diffuser tube, which increases the cost of electricity for the blower.

A wastewater treatment device is being considered that processes wastewater by attaching microorganisms to a gas supply body that is permeable to gas but not permeable to liquid. Since this device can suppress the pressure applied to air, it is possible to reduce power costs. Examples of such gas supply bodies are disclosed in Patent Documents 1 and 2.

Patent No. 3743771 Patent No. 4680504

In an aerobic microbial wastewater treatment device using a gas supply, condensed water is generated inside the gas supply due to permeation of water vapor through the gas supply or condensation of water vapor in the supplied air. As a result, a part of the air supply gas flow path is blocked and the air supply efficiency is reduced.

An object of the present invention is to provide a gas supply, a gas supply unit, and a system in which condensed water can be easily discharged from the gas supply and oxygen dissolution efficiency can be maintained.

The gas supply body of the first aspect is a gas supply body used in a wastewater treatment device that purifies wastewater using the action of microorganisms,
waterproof and air permeable membrane,
a liquid feeding section that discharges the liquid in the internal space partitioned by the waterproof air-permeable membrane to the outside;
a valve disposed at the bottom of the internal space, connected to the liquid feeding section, and opened when liquid is present;
Equipped with

The gas supply body according to the second aspect is the gas supply body according to the first aspect, and the valve is a float type liquid open/air close valve.

The gas supply body according to the third aspect is the gas supply body according to the first or second aspect, and the liquid supply section is an air supply section that supplies air to the internal space.

The gas supply body according to the fourth aspect is the gas supply body according to any one of the first to third aspects, and further includes a gas delivery layer.

The gas supply unit according to the fifth aspect includes a plurality of gas supply bodies according to any one of the first to fourth aspects.

The system according to the sixth aspect is a system that uses the action of microorganisms to purify wastewater,
A supply unit according to a fifth aspect,
A pump connected to the liquid sending part of each gas supply body,
including.

A system according to a seventh aspect is a system according to a sixth aspect, in which the liquid feeding section can also be connected to a blower that supplies gas to the liquid feeding section by switching.

The wastewater treatment device according to the eighth aspect is the gas supply body according to any one of the first to fourth aspects, or
A supply unit according to a fifth aspect,
including.

In the gas supply body/supply body unit/system of the present invention, since condensed water can be easily discharged from the gas supply body, oxygen dissolution efficiency can be maintained. Furthermore, since condensed water can be easily discharged from a plurality of gas supply bodies using one pump, work efficiency is high.

FIG. 1 is a vertical cross-sectional view of the wastewater treatment device 100 of the first embodiment. FIG. 1 is a vertical cross-sectional view of the wastewater treatment apparatus 100 of the first embodiment in a direction 90° different from FIG. 1. FIG. FIG. 2 is a vertical cross-sectional view of the gas supply body 10 of the first embodiment. FIG. 2 is a perspective view of a gas delivery layer 12 constituting the gas supply body 10 of the first embodiment. FIG. 2 is a diagram schematically showing how microorganisms decompose organic matter in wastewater W using the gas supply body 10 of the first embodiment. FIG. 3 is a diagram showing a state in which the liquid feeding section 31 of the first embodiment is closed by a valve 30. FIG. FIG. 3 is a diagram showing a state in which a valve 30 disposed in a liquid feeding section 31 of the first embodiment is open. FIG. 3 is a diagram showing a sealed structure of the receiving side 34 of the liquid sending section 31 of the first embodiment. It is a vertical cross-sectional view of wastewater treatment equipment 100a of a 2nd embodiment. FIG. 8 is a vertical sectional view of the wastewater treatment apparatus 100a of the second embodiment in a direction different by 90 degrees from FIG.

<First embodiment>
(Wastewater treatment equipment 100)
The wastewater treatment apparatus 100 of the present embodiment utilizes the action of aerobic microorganisms contained in the wastewater to decompose at least one organic substance or nitrogen source in the wastewater to purify the wastewater. As shown in FIG. 1, the wastewater treatment device 100 includes a wastewater treatment tank 51 and a system 50.

(Wastewater treatment tank 51)
As shown in FIG. 1 or 2, the wastewater treatment tank 51 is a bottomed container in which wastewater W is stored, and an inlet 51a and an outlet 51b are provided on opposing sides.

In this embodiment, the inlet 51a and the outlet 51b are always open. The wastewater W is continuously or intermittently supplied from the inlet 51a toward the outlet 51b, which is located opposite the inlet 51a. flow).

The volume of the wastewater treatment tank 51 is not particularly limited, but may be, for example, 1 m ³ or more and 10,000 m ³ or less.

(System 50)
The system 50 includes a supply unit 52, a gas supply source 53 (blower 53a), and a pump 54a.

(Supply unit 52)
As shown in FIG. 1, the supply unit 52 is a unit of the gas supply 10, and is arranged inside the wastewater treatment tank 51. In FIG. 1, the supply unit 52 includes a plurality of gas supplies 10 arranged in parallel. The supply body unit 52 is arranged so that the portion of each gas supply body 10 excluding the upper end portion is immersed in the waste water W during use.

(Gas supply body 10)
Each gas supply body 10 is a structure that supplies gas supplied from the opening 21b into the waste water W while being immersed in the waste water W of the waste water treatment tank 51. For example, the gas supply body 10 includes a gas delivery layer 12, a waterproof gas permeable membrane 21, an air supply section 31a, a liquid supply section 31, and a valve 30, as shown in FIG. The valve 30 controls the inflow and outflow of liquid and gas into and out of the gas supply body 10 . The air supply section 31a is a pipe that sends the air (oxygen) sent into the blower 53a into the inside of the gas supply body 10. The liquid feeding section 31 is a pipe that connects the pump 54a and the inside of the gas supply body 10. The liquid sending unit 31 discharges the liquid inside the gas supply body 10 to the outside. In this embodiment, the air supply section 31a and the liquid supply section 31 share many pipes.

Each gas supply body 10 constituting the supply body unit 52 is a structure that supplies gas supplied from the opening 21b into the waste water W while being immersed in the waste water W of the waste water treatment tank 51. The gas supplied into the wastewater W via the gas supply body 10 is preferably a gas containing oxygen in order to promote activation of aerobic microorganisms in the wastewater W. Specifically, it may be air or pure oxygen. In the illustrated example, gas from the gas supply source 53 is supplied to the opening 21b (air supply section 31a), and an air supply device or the like can be used as the gas supply source 53. Note that from the viewpoint of keeping manufacturing costs low, the air in the atmosphere may be taken into the gas supply body 10 as it is through the opening 21b without using the gas supply source 53.

As shown in FIG. 2, each gas supply body 10 is a flat member, and is arranged so that its surface extends in the vertical direction (depth direction) and the lateral direction (horizontal direction). There is. Thereby, the contact area with wastewater W is efficiently ensured. Moreover, by arranging each gas supply body 10 so that the side surface of each gas supply body 10 is parallel to the straight line connecting the inflow port 51a and the outflow port 51b, the wastewater treatment tank 5 The wastewater W supplied inside flows smoothly toward the outlet 51b. Note that the number of gas supply bodies 10 constituting the supply body unit 52 is not necessarily plural, and may be one.

If the interval between the gas supply bodies 10 is defined as "the distance between the outer surfaces of two adjacent gas supply bodies 10, not including the thickness of the gas supply bodies 10", then the interval between the gas supply bodies 10 is 5 mm or more and 200 mm or less It is preferable that If the interval between the gas supply bodies 10 is less than 5 mm, there is a risk that microorganisms growing on the waterproof air-permeable membrane 21 will cause clogging. If the interval between the gas supply bodies 10 exceeds 200 mm, the efficiency of contact with wastewater may deteriorate, making it difficult to improve wastewater treatment performance. In order to reliably avoid the above problem, it is more preferable that the interval between the gas supply bodies 10 be 15 mm or more and 50 mm or less.

FIG. 3 is a vertical cross-sectional view of the gas supply body 10. As shown in FIG. 3, the gas supply body 10 includes a gas delivery layer 12 and a waterproof air-permeable membrane 21, and the gas delivery layer 12 is arranged in a bag constituted by the waterproof air-permeable membrane 21. Ru. The bag is made by overlapping two waterproof and air-permeable membranes 21, 21 and bonding the three ends of these waterproof and air-permeable membranes 21, 21, and the upper end (gas supply layer 12). It has an opening 21b (see FIG. 3) at the side end. Then, the gas delivery layer 12 is inserted into the bag through the opening 21b, so that the outer periphery of the gas delivery layer 12 is covered with the waterproof air-permeable membrane 21. Note that the position or shape of the opening 21b is not limited, and for example, a portion of each end ( upper side of the bag) may be formed as an opening.

(Waterproof and air permeable membrane 21)
The waterproof air-permeable membrane 21 is immersed in liquid (wastewater) so that the outermost layer is in contact with the liquid (wastewater), and allows oxygen supplied to the inside (gas delivery layer 12 side) to permeate to the outside. By doing so, oxygen is supplied into the liquid (wastewater). The waterproof air-permeable membrane 21 allows air to permeate from the inside (gas delivery layer 12) to the outside (wastewater W) when the gas supply body 10 is immersed in the wastewater treatment tank 51, and allows air to pass through from the inside (gas delivery layer 12) to the outside (wastewater W). It has the property of not allowing waste water to permeate from the inside (gas delivery layer 12). As a result, aerobic microorganisms in the wastewater W gather on the surface 21a of the waterproof air-permeable membrane 21 to which air (oxygen) is continuously supplied, as shown in FIG. Therefore, microorganisms adhere to the surface 21a of the waterproof air-permeable membrane 21, and a biofilm 214 is formed. Then, by the action of microorganisms contained in the wastewater W or held on the surface 21a, microorganisms or nitrogen compounds dissolved or dispersed in the water are decomposed, and the wastewater is purified. .

Specifically, as shown in FIG. 3, the waterproof and air-permeable membrane 21 includes a base material 211, a gas-permeable nonporous layer 212, and a microorganism support layer 213. In the illustrated example, the waterproof and air-permeable membrane 21 includes a base material 211, a gas-permeable nonporous layer 212, and a microorganism support layer 213, which are laminated in this order. The microorganism support layer 213 is the outermost layer that comes into contact with the wastewater W. Note that, unlike the illustrated example, the waterproof and air-permeable membrane 21 may be one in which a gas-permeable non-porous layer 212, a base material 211, and a microorganism support layer 213 are laminated in this order.

(Base material 211)
The base material 211 is a microporous membrane made of thermoplastic resin. The microporous membrane is a membrane provided with many fine through holes. Materials for the base material 211 include polyolefin, polystyrene, polysulfone, polyethersulfone, polyarylsulfone, polymethylpentene, polytetrafluoroethylene, and fluororesins including polyvinylidene fluoride, polybutadiene, and poly(dimethylsiloxane). Polymeric materials selected from silicone-based polymers, copolymers of these materials, and the like may be included.

The method for manufacturing the base material 211, which is a microporous membrane, is not particularly limited, but for example, the base material 211 may be manufactured by any one of a phase separation method, a stretching pore method, a melt recrystallization method, a powder sintering method, a foaming method, and a solvent extraction method. material 211 can be manufactured. Further, the base material 211 may be a self-assembled honeycomb microporous membrane.

The thickness of the base material 211 is preferably 10 μm to 500 μm, more preferably 50 μm to 200 μm. The thickness of the base material 211 is a value measured by JIS1913:2010 General Nonwoven Fabric Test Method 6.1 Thickness Measuring Method.

The pore diameter of the base material 211 is preferably 0.01 μm to 50 μm from the viewpoint of preventing defects in the gas permeable nonporous layer, and 0.1 μm to 30 μm from the viewpoint of maintaining high strength and gas permeability. It is more preferable. The pore diameter is a pore diameter determined by observing the surface using a scanning electron microscope (SEM) and using the observed image by the method described below. Observation can be performed at any magnification as long as the pore diameter of the object to be observed can be appropriately calculated.

(Method for determining pore diameter)
The image obtained by SEM observation is binarized, and the pore diameter is calculated by image analysis. When calculating, the pore diameter is approximated to an ellipse, the length of the long axis of the ellipse is taken as the pore diameter, and the average value is evaluated. Alternatively, the pore diameter of the base material 211 is defined as the average pore diameter determined from pore diameter distribution measurement (palm porosimetry) using a capillary condensation method. In palm porosimetry, the relationship between the differential pressure between atmospheric pressure and the measured pressure and the gas permeation flow rate is determined from the gas permeation flow rate measured when the measurement pressure of the gas applied to the sample is gradually increased. To determine the pore diameter, a wet curve measured on a wet sample after immersing the sample in a wetting liquid with a known surface tension and a dry curve measured on a dry sample are determined. By gradually increasing the pressure within a predetermined pressure range, information regarding the diameter of the through pores within the sample can be obtained. The average pore diameter is determined by finding a point X where the wet curve intersects with a curve having a slope of 1/2 of the dry curve (half dry curve), and substituting this into the equation d=2860×γ/DP. In the above equation, d is the average pore diameter (mm), γ is the surface tension of the wetting liquid (dynes/cm), and DP is the differential pressure between the atmospheric pressure and the gas pressure at point X (Pa). For the measurement, a palm porometer (CFP-1500-AEC) manufactured by Porous Materials can be used. The test conditions include, for example, the test temperature is room temperature (20°C ± 5°C), the wetting liquid is Galwick (surface tension 15.7 dynes/cm), the pressurized gas is compressed air, the diameter of the sample used is 33 mm, and the maximum supply pressure. can be measured at 250 psi, and the rate of increase in differential pressure can be measured at 4 psi/min. When preparing a wet sample, the sample can be sufficiently moistened by putting the wetting liquid in which the sample is immersed into a desiccator and deaerating it.

(Gas permeable nonporous layer 212)
The gas-permeable nonporous layer 212 is a layer that has pores with a smaller diameter than the pores of the base material, or is a layer whose pore diameter cannot be detected and is gas permeable. The pore diameter of the gas-permeable nonporous layer 212 can be measured in the same manner as the pore diameter of the base material 211.

Examples of the gas that permeates through the gas-permeable nonporous layer 212 include oxygen, carbon dioxide, nitrogen, hydrogen, alcohols such as methanol and ethanol, organic solvents, and mixed gases thereof. From the viewpoint of effectively cultivating and activating microorganisms, the gas is preferably oxygen or a mixed gas containing oxygen. Gas permeability can be measured by the method specified in JIS K 7126.

The gas permeable non-porous layer 212 may be made of thermoplastic resin or thermosetting resin. The thermosetting resin may be a thermosetting resin or a resin that is cured by ultraviolet irradiation. Further, the resin may be cured by organic peroxide crosslinking, addition reaction crosslinking, or condensation crosslinking.

The material for the gas permeable non-porous layer 212 may include a thermosetting polymer selected from polyolefin, polystyrene, polysulfone, polyethersulfone polytetrafluoroethylene, acrylic resin, polyurethane resin, and copolymers of these materials. Further, a silicone-based silicone resin such as poly(dimethylsiloxane) having a siloxane skeleton of (Si-O-Si)n (n=integer) can be used. Among these, it is particularly preferable to use urethane resins and silicone resins.

Examples of the above polyurethane resins include "Asaflex 825" (manufactured by Asahi Kasei Corporation), "Pelecene 2363-80A", "Pelecene 2363-80AE", "Pelecene 2363-90A", "Peresene 2363-90AE",・"Heimlen Y-237NS" (manufactured by Dainichiseika Kogyo Co., Ltd.) can be used. The formulation and composition of the silicone resin, silicone polymer, or silicone resin composition for obtaining them are not particularly limited. The monomers used in the silicone resin composition may be monofunctional, bifunctional, trifunctional, or tetrafunctional, and may be used alone or in combination of two or more. As the monomer, halogenated alkylsilane, unsaturated group-containing silane, aminosilane, mercaptosilane, epoxysilane, etc. may be used. Examples of monomers used include monomers represented by the following chemical formula. _{HSiCl3 , SiCl4} , _MeSiHCl2 , _Me3SiCl , MeSiCl3, _Me2SiCl2 , _Me2HSiCl , _PhSiCl3 , _{Ph2SiCl2 ,} MePhSiCl2 _{, Ph2MeSiCl} , _CH2 = _CHSiCl3 ,Me _{( CH2} =CH _{) SiCl2} , _Me2 ( _CH2 =CH ₎ SiCl, _{( CF3CH2CH2} ) _{MeSiCl2, ( CF3CH2CH2 ) SiCl3 , CH18H37SiCl3} (in the chemical formula "= ” represents a double bond, “Me” represents a methyl group, and “Ph” represents a phenyl group). The monomers may be used alone or in combination of two or more. Other organic groups include alkyl groups such as propyl, isopropyl, butyl, isobutyl, tert-butyl, hexyl, octyl, and decyl; phenyl, tolyl, xylyl, and naphthyl groups; Aryl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; aralkyl groups such as benzyl, 2-phenylethyl and 3-phenylpropyl groups, etc. may also be used. Among these, methyl group, phenyl group, or a combination of both are preferred. This is because a component having a methyl group, a phenyl group, or a combination of both is easy to synthesize and has good chemical stability. In addition, when a polyorganosiloxane with particularly good solvent resistance is used, a combination of a methyl group, a phenyl group, or a combination of both and a 3,3,3-trifluoropropyl group may be used. preferable. Further, the silicone resin composition may contain organoalkoxysilane. Examples of the organoalkoxysilane include compounds represented by the following chemical formula, which may be used alone or in combination of two or more. _Me3SiOCH3 , _Me2Si ( _OCH3 ) _{2 ,} MeSi( _OCH3 ) ₃ , Si( _OCH3 ) ₄ , Me( _C2H5 ) _Si ( _{OCH3 ) 2} , _C2H5Si ( _OCH3) ) ₃ , C ₁₀ H ₂₁ Si(OCH ₃ ) ₃ , PhSi(OCH ₃ ) ₃ , Ph ₂ Si(OCH ₃ ) ₂ , MeSiOC ₂ H ₅ , Me ₂ Si(OC ₂ H ₅ ) ₂ , Si(OC _{2 H5} ) ₄ , _C2H5Si ( _{OC2H5 ) 3} , PhSi( _{OC2H5 ) 3 , Ph2Si} ( _{OC2H5 ) 2} .

Furthermore, the silicone resin composition may contain organosilanol. Examples of organosilanols include compounds represented by the following chemical formula, which may be used alone or in combination of two or more. _Me3SiOH , _Me2Si (OH) ₂ , MePhSi(OH) ₂ , ( _{C2H5 ) 3SiOH} , _Ph2Si (OH) ₂ , _Ph3SiOH .

The reaction method for obtaining the silicone polymer used in the silicone resin may include, for example, hydrolysis of chlorosilane, ring-opening polymerization of cyclic dimethylsiloxane oligomer, and the like. Examples of the polymers used include dimethyl-based polymers, methylvinyl-based polymers, methylphenylvinyl-based polymers, and methylfluoroalkyl-based polymers.

The method of curing the silicone polymer, ie, the method of reacting (vulcanizing) it to obtain a silicone resin, is not particularly limited. Heat vulcanization or room temperature vulcanization may be used. In the pre-reaction state, either a millable silicone resin composition or a liquid rubber silicone resin composition may be used. The polymer used in the millable silicone resin composition preferably has a degree of polymerization of about 4,000 to 10,000. Moreover, it may be a one-liquid type or a two-liquid type. Examples of reaction methods include dehydration condensation reaction between silanol groups (Si-OH), condensation reaction between silanol groups and hydrolyzable groups, methylsilyl group (Si-CH ₃ ), and vinylsilyl group (Si-CH=CH ₂ ). A reaction with an organic peroxide, an addition reaction between a vinylsilyl group and a hydrosilyl group (Si--H), a reaction with ultraviolet rays, a reaction with an electron beam, etc. may be used.

(Microorganism support layer 213)
The microorganism support layer 213 is a layer that retains microorganisms on its surface or inside, has a space in which microorganisms can grow, and allows organic matter in water to pass therethrough. Examples of the material for the microorganism support layer 213 include mesh, woven fabric, nonwoven fabric, foam, and porous sheets such as microporous membranes. Porous sheet materials include polyolefin resin, polystyrene resin, polyester resin, polyvinyl chloride resin, acrylic resin, urethane resin, epoxy resin, polyamide resin, methyl cellulose resin, ethyl cellulose resin, polyvinyl alcohol resin, vinyl acetate resin, phenol resin, Examples include fluororesins and polyvinyl butyral resins, polyimides, polyphenylene sulfides, para- and meta-aramids, polyarylates, carbon fibers, glass fibers, aluminum fibers, steel fibers, ceramics, and the like. Considering microbial adhesion and processability, polyolefin resins, polyester resins, polyamide resins, acrylic resins, polyurethane resins, and carbon fibers are preferred. The basis weight of the microorganism support layer 213 is preferably 2 g/m ² or more and 500 g/m ² or less, more preferably 10 g/m ² or more and 200 g/m ² or less. The basis weight of the microorganism support layer 213 is a value measured in JIS1913:2010 General Nonwoven Fabric Test Method 6.2 mass per unit area. When the basis weight of the microorganism support layer 213 is 2 g/m ² or more, the microorganism support layer 213 can easily retain microorganisms because the surface is uneven. Furthermore, since the basis weight of the microorganism support layer 213 is 500 g/m ² or less, a space in which microorganisms can grow is created inside the microorganism support layer 213, making it easier to retain the microorganisms, and the space allows oxygen to be fed to the microorganisms. This has the effect of making supply easier.

The thickness of the microorganism support layer 213 is preferably 5 μm or more and 2000 μm or less, more preferably 20 μm or more and 500 μm or less. The thickness of the microorganism support layer 213 is a value measured by JIS1913:2010 General Nonwoven Fabric Test Method 6.1 Thickness Measuring Method.

Note that the microorganism support layer 213 may be formed by surface treatment of the base material 211. In this way, the roughness of the surface of the base material 211 and the membrane potential can be increased by the above-mentioned surface treatment, so that the adhesion of microorganisms can be improved. For example, the above-mentioned surface treatment may include graft polymerization of glycidyl methacrylate and further reaction with diethylamine or sodium sulfite. Alternatively, as the above surface treatment, ammonia or ethylamine may be reacted after graft polymerization of glycidyl methacrylate. The waterproof air-permeable membrane 21 has a gas-permeable non-porous layer 212, and is characterized by having a liquid permeability of 1 or less as determined by a liquid permeability measurement test.

(Liquid permeability measurement test)
The waterproof and air-permeable membrane 21 of this embodiment has a sheet shape (flat plate shape). The liquid permeability measurement test can be carried out as follows.
(1) A test piece was prepared by laminating a 50 mm square polyethylene terephthalate resin nonwoven fabric (fabric weight: 220 to 300 g/mm ² ) on the opposite side of the 50 mm square waterproof and air permeable membrane 21 to the surface in contact with the treated water. 10 test pieces are prepared.
(2) Place each of the 10 test pieces on a glass plate so that the surface on the nonwoven fabric side is in contact with the glass plate, and fix the four corners of the test piece to the glass plate using tape with a width of 10 mm.
(3) Add 0.7% by mass of perfluoroalkyl group-containing carboxylic acid salt and 0.3% of Allura Red (CAS No.:25956-17-6) to ion-exchanged water on the side of each test piece that comes into contact with the treated water. Drop 10 mL of the test solution dissolved in mass% at once with a pipette, taking care not to overflow the test piece.
(4) Let each test piece stand for 18 hours at a temperature of 25±5°C and a humidity of 50±10%.
(5) The number of test pieces in which it can be confirmed from the glass plate side that the test liquid has passed through the test piece is defined as the transmittance.

In addition, in the step (1) above, the method of laminating the waterproof air-permeable membrane 21 and the nonwoven fabric may be simply by overlapping them.

More specifically, as a method of fixing the test piece in the step (2) above, a method of fixing the four corners corresponding to the vertices of the test piece with 10 mm square tape can be mentioned.

In the step (3) above, if there is a large amount of test liquid and it is unavoidable that it protrudes from the test piece when dropped, it is also preferable to reduce the amount of test liquid by half and conduct the test.

(Gas delivery layer 12)
FIG. 4 is a perspective view showing the gas delivery layer 12. The gas delivery layer 12 is a hollow plate-like member made of paper, resin, or metal. The gas delivery layer 12 is a structure having a gas flow path S that sends out the gas supplied from the first end side along the first direction. Gas from the gas supply source 53 (FIG. 1) is supplied to the lower end of the gas delivery layer 12 via the air delivery section 31a. The gas delivery layer 12 has a gas flow path S that sends out the supplied gas in a first direction (see the dashed line in FIG. 4), and releases the gas from the gas passage hole 13 on the side surface.

More specifically, as shown in FIG. 4, the gas delivery layer 12 includes a plurality of core materials 12a, a front liner 12b, and a back liner 12c. The front and back surfaces of the gas delivery layer 12 are constituted by a front liner 12b and a back liner 12c, which are plate-shaped members.

The plurality of core materials 12a each extend in the first direction, and are arranged at predetermined intervals in a direction perpendicular to the first direction. By sandwiching these plurality of core materials 12a between the front liner 12b and the back liner 12c, a plurality of gas flow paths S defined by the core materials 12a are created in the space between the front liner 12b and the back liner 12c. is formed.

Moreover, each core material 12a functions as a support portion to prevent the space between the front liner 12b and the back liner 12c from being reduced when pressed from the front liner 12b and back liner 12c sides. When the gas supply body 10 is immersed in wastewater W as shown in FIG. 1 or 2, the core material 12a is arranged between the front liner 12b and the back liner so that the cross-sectional area of the gas flow path S is not reduced by water pressure. 12c. Thereby, a sufficient amount of gas can be ensured in the gas delivery layer 12 (gas channel S).

A plurality of gas passage holes 13 are formed in each of the front liner 12b and the back liner 12c. The gas passage hole 13 is a through hole formed in the front liner 12b and the back liner 12c, and the gas passage hole 13 allows the gas passage S to communicate with the waterproof gas permeable membrane 21. The flowing gas is supplied into the liquid via the waterproof air-permeable membrane 21.

Note that, for example, the gas passage holes 13 are formed when the gas delivery layer 12 is molded. Alternatively, the gas passage holes 13 may be formed by processing the front liner 12b and the back liner 12c after forming the gas delivery layer 12. A porous sheet may be used for the front liner and the back liner. Further, a porous sheet may be used for the gas delivery layer if sufficient gas supply performance is obtained.

Materials for each member constituting the gas delivery layer 12 include paper, ceramic, aluminum, iron, plastic (polyolefin resin, polystyrene resin, polyester resin, polyvinyl chloride resin, acrylic resin, urethane resin, epoxy resin, polyamide resin, Examples include methyl cellulose resin, ethyl cellulose resin, polyvinyl alcohol resin, vinyl acetate resin, phenol resin, fluororesin, and polyvinyl butyral resin).

Note that the material of the gas delivery layer 12 is preferably paper, aluminum, iron, polyolefin resin, polystyrene resin, vinyl chloride resin, or polyester resin because of their excellent strength.

In addition, from the viewpoint of keeping material costs low, it is preferable to use paper, resin such as polyolefin, polystyrene, vinyl chloride, polyester, metal such as aluminum, etc. as the material for the gas delivery layer 12, for example. Furthermore, the material cost of the gas delivery layer 12 can be kept low by using a cardboard formed so that the gas flow path S extends in the first direction (see the dashed line in FIG. 4) as the gas delivery layer 12. Can be done.

The gas permeation holes of the gas delivery layer 12 can have various hole shapes such as a circular shape and a polygonal shape (including a honeycomb structure). Although the shape of the hole is not particularly limited, a polygonal shape is preferred, and specifically a rectangular or square shape is preferred.

(Liquid feeding part 31, valve 30)
The liquid sending unit 31 is a structure having a mechanism for transporting fluids such as liquids such as water and gases such as air. Regarding the liquid sending section 31, there is no particular limit to the range, but in consideration of ease of insertion into the gas supplying body 10, the outer diameter of the piping of the liquid sending section 31 is set to be equal to the thickness of the gas sending layer 12. The outer diameter is preferably 0.1 times or more and 10 times or less. In the case of a structure without the gas delivery layer 12, the outer diameter of the piping of the liquid sending part 31 is preferably 1 mm or more and 200 mm or less, considering ease of connection of the liquid sending part 31 of the system 50. Furthermore, in order to prevent the float 30a from being sucked into the liquid feeding section 31, the inner diameter of the piping of the liquid feeding section 31 is preferably smaller than the diameter of the float 30a.

The valve 30 that becomes open when liquid is present is a structure that has a mechanism that opens the valve 30 when immersed in liquid to form a flow path. The valve 30 may be located within the liquid feeding section 31, but is preferably located at the tip of the liquid feeding section 31. With this feature, the flow path is blocked and gas is not discharged from the gas supply body 10 after the liquid has been discharged, so one pump 54a is used to simultaneously drain the liquid from one or more gas supply bodies 10. It can be discharged. There are no particular restrictions on the valve 30, which opens when a liquid is present, but it is preferably made of resin or stainless steel, which is resistant to corrosion since it comes into contact with liquids such as water. Furthermore, considering the ease of insertion into the gas supply body 10, the size of the valve is preferably 0.1 times or more and 10 times or less the thickness of the gas delivery layer 12. In the case of a structure without the gas delivery layer 12, the size of the valve is preferably 1 mm or more and 200 mm or less in consideration of ease of connection with the liquid feeding section 31.

The valve 30 is installed at the bottom of the internal space of the gas supply body 10. The bottom does not necessarily have to be in contact with the lowest part of the internal space, and may be in a state where sufficient gas can be supplied even if the space located horizontally below the valve 30 is filled with water. If the vertical length of the portion of the internal space below the water surface is 100% starting from the lowest point of the internal space, the valve 30 should be located at the lowest point from the viewpoint of efficiently supplying air. The air supply efficiency is preferably 50% or less, more preferably 20% or less, and even more preferably 10% or less, but the air supply efficiency is highest when the valve 30 is in contact with the lowest part of the internal space.

The valve 30 is a liquid open/air closed valve, and is a float type liquid open/air closed valve. A liquid-open, air-closed valve is a valve that is open when liquid is present and closed when gas is present. The float type liquid open/close valve is a valve 30 having a structure including a float 30a and a space in which the float 30a can move in the vertical direction. As shown in FIGS. 6A and 6B, for example, a valve 30 constituted by a float 30a that floats on water (having a specific gravity of 1 or less) can be used as the float type liquid open/close valve. When the valve 30 is immersed in water, the float 30a floats to open the flow path (FIG. 6B), and when the valve is not immersed in water and gas is not supplied, the float 30a floats up to open the flow path (FIG. 6B). 30a is lowered and the flow path is blocked (FIG. 6A). In order for liquid/gas to flow into the valve 30, it is necessary to have at least one inflow hole 32, 33. The inflow holes 32 and 33 may have a hole diameter smaller than the size of the float 30a, and there are no particular restrictions on their material, but they are preferably made of resin or stainless steel, which is resistant to corrosion since they come into contact with liquids such as water. . Regarding the valve 30 constituted by the float 30a, there is no particular restriction on the shape of the float 30a, but since it needs to float on liquid such as water, hollow floats, foam-shaped floats, and materials with a specific gravity of 1 or less may be used. It is preferable that the float be used as a float.

As shown in FIG. 7, it is preferable that the structure is such that the float 30a and its receiving side 34 can come into close contact when the float 30a descends and the flow path is closed. In order to obtain a structure in which the float 30a and its receiving side 34 can be brought into close contact with each other, it is preferable to use a flexible material such as elastomer or rubber for the receiving side 34. Specific rubber materials include natural rubber, butyl rubber, silicone rubber, nitrile rubber, acrylic rubber, polyisobutene rubber, chloroprene rubber, butadiene rubber, and elastomers include olefin elastomers, styrene elastomers, vinyl chloride elastomers, Examples include urethane elastomers, polyester elastomers, and polyamide elastomers. The structure that allows the float 30a and its receiving side 34 to come into close contact is preferably a pleated portion or flexible packing on the receiving side 34, and for example, a rubber seal, D-shaped rubber, etc. can be used.

In the system 50 of this embodiment, the liquid feeding section 31 and the air feeding section 31a are shared. That is, when discharging the liquid accumulated in the internal space of the gas supply body 10 to the outside, the liquid feeding section 31 is sucked by the pump 54a to discharge the liquid to the outside. On the other hand, when the liquid feeding section 31 is used as the air feeding section 31a, the blower 53a sends air to the air feeding section 31a. In the float type liquid open/close valve 30, the float 30a floats due to the feeding pressure (FIG. 6A), and air (oxygen) is sent into the internal space of the gas supply body 10.

<Second embodiment>
(Wastewater treatment equipment 100a)
Similar to the wastewater treatment device 100 of the first embodiment, the wastewater treatment device 100a of the second embodiment decomposes at least one organic substance or nitrogen source in the wastewater by utilizing the action of aerobic microorganisms contained in the wastewater. and purify wastewater. The wastewater treatment apparatus 100a of the second embodiment includes a wastewater treatment tank 51 and a system 50a, as shown in FIGS. 8 and 9. The wastewater treatment tank 51 is exactly the same as that in the first embodiment, so a description thereof will be omitted.

The system 50a of the second embodiment includes a supply unit 52a, a blower 53a, and a pump 54a. Although the system 50 of the first embodiment had a supply unit 52, the system 50a of the second embodiment includes a hollow fiber type supply unit 52a instead.

(Hollow fiber type supply unit 52a, gas supply unit 10a)
The supply unit 52a (gas supply 10a) of this embodiment includes a hollow fiber membrane strand 122, an upper header 120, a lower header 121, an air supply section 31a, a liquid supply section 31, and a valve 30. ing. The supply unit 52a is placed in the wastewater W as shown in FIG. Oxygen or air is supplied to the inside of the hollow fiber membrane strand 122 by the blower 53a via the air supply section 31a and the upper header 120. The supplied oxygen seeps out onto the surface of the hollow fiber membrane strand 122, and microorganisms treat the wastewater W on the surface of the hollow fiber membrane strand 122. Hollow fiber membrane strand 122 is non-porous. The hollow fiber membrane strand 122 is made up of approximately 5 to 50 single hollow fiber membranes each having a diameter of approximately 50 to 100 μm. The hollow fiber membrane strands 122 are arranged in the vertical direction, and the upper end of each hollow fiber membrane strand 122 is connected to the upper header 120, and the lower end is connected to the lower header 121. The inside of the hollow fiber membrane strand 22 communicates with the upper header 20 and the lower header 121, respectively. Each header 120, 121 has a hollow tubular shape made of potting material. As shown in FIG. 9, a plurality of hollow fiber membrane units each consisting of a pair of headers 120, 121 and a hollow fiber membrane strand 22 are arranged in parallel.

The hollow fiber membrane strand 122 supplies oxygen from the inside to the outside surface while preventing moisture from entering the inside from the waste water W on the outside surface. That is, the hollow fiber membrane strand 122 includes a waterproof permeable membrane.

The waterproof air-permeable membrane (hollow fiber membrane strand 122) of this embodiment has a liquid permeability of 1 or less as determined by the liquid permeability measurement test described below.

(Liquid permeability measurement test)
The test method for measuring liquid permeability in hollow fiber type waterproof and air permeable membranes is shown below.
(1') Obtain 10 gas supply bodies each having a length of 50 mm in the longitudinal direction from a part or the whole of a hollow fiber type gas supply body having a waterproof air-permeable membrane.
(2') Seal the ends of each gas supply body with instant adhesive.
(3') Direct the unsealed open end of each gas supply body vertically upward.
(4') 0.7% by mass of perfluoroalkyl group-containing carboxylic acid salt and 0.3% by mass of Allura Red (CAS No.: 25956-17-6) were dissolved in ion-exchanged water through the open end of each gas supply body. Pour the test liquid into the gas supply body until it overflows from the gas supply body, wipe off the overflowing test liquid, and then seal the open end with an instant adhesive.
(5') Each gas supply body was fixed diagonally to a 50 mm square polyethylene terephthalate resin nonwoven fabric (fabric weight: 220 to 300 g/mm ² ) using a 10 mm wide tape to obtain a test piece.
(6') Fix the four corners of each test piece to a glass plate using tape with a width of 10 mm.
(7') Each test piece is allowed to stand for 18 hours under conditions of a temperature of 25±5°C and a humidity of 50±10%.
(8') The number of test pieces in which it can be confirmed from the glass plate side that the test liquid has passed through the test piece is defined as the transmittance.

Examples of instant adhesives used in steps (2') and (4') above include vinyl acetate adhesives, ethylene vinyl acetate adhesives, epoxy adhesives, cyanoacrylate adhesives, and acrylic adhesives. , chloroprene rubber adhesive, and styrene-butadiene rubber adhesive.

More specifically, as a method of fixing the test piece in the step (6') above, a method of fixing the four corners corresponding to the vertices of the test piece with 10 mm square tape can be mentioned.

(Liquid feeding part 31, valve 30)
The valve 30 of the second embodiment is arranged inside the lower header 121. The liquid accumulated in the lower header is discharged from the inside of the gas supply body 10a to the outside via the liquid feeding section 31. At this time, the inside of the liquid feeding section 31 is evacuated using the pump 54a. The configuration of the valve 30 is exactly the same as that in the first embodiment, so a description thereof will be omitted.

In the system 50a of this embodiment, the air supply section 31a is arranged independently of the liquid supply section 31. The liquid feeding section 31 may be arranged so as to also serve as the air feeding section 31a.

Although the embodiments of the present disclosure have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the present disclosure as described in the claims. .

10, 10a Gas supply body 12 Gas supply layer 21 Waterproof gas permeable membrane 30 Liquid open/close valve 30a Float 31 Liquid supply section 31a Air supply section 50, 50a System 51 Waste water treatment tank 52, 52a Supply unit 53 Gas supply source 53a Blower 54a Pump 100, 100a Wastewater treatment device

Claims (7)

A gas supply body used in wastewater treatment equipment that purifies wastewater using the action of microorganisms,
A bag made of a waterproof and air-permeable membrane that defines an internal space in which liquid accumulates ;
a liquid feeding unit that discharges the liquid in the internal space to the outside;
a valve disposed at the bottom of the internal space, connected to the liquid feeding section, and opened when liquid is present;
Equipped with
The valve is a float type liquid open/close valve,
The float type liquid open/close valve has a float,
The float rises when liquid accumulates in the internal space, and the liquid in the internal space is discharged from the internal space to the outside.
gas supply body. The liquid supply unit is an air supply unit that supplies air to the internal space.
The gas supply body according to claim 1 . The gas supply further includes a gas delivery layer.
The gas supply body according to claim 1 or 2 . A plurality of gas supply bodies according to any one of claims 1 to 3 are provided,
supply unit. A system that uses the action of microorganisms to purify wastewater,
A supply unit according to claim 4 ;
A pump connected to the liquid sending part of each gas supply body,
system containing. The liquid feeding section can also be connected to a blower that supplies gas to the liquid feeding section by switching.
The system according to claim 5 . The gas supply body according to any one of claims 1 to 3 , or
The supply unit according to claim 4 ,
wastewater treatment equipment including;

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