JP2023051827A - Wastewater treatment system - Google Patents

Abstract

To prevent condensation of water dew inside a gas supply body for supplying gas to microorganisms in a wastewater treatment system that purifies wastewater using the action of microorganisms.SOLUTION: A wastewater treatment system (50) includes: (i) a plurality of gas suppliers (10) having a waterproof gas-permeable membrane (21), in which gas supplied to the interior space of the gas suppliers (10) is supplied to microorganisms in wastewater outside the waterproof gas-permeable membrane (21); and (ii) an air supply unit (30) for supplying gas to the internal space of the gas suppliers (10). The air supply unit (30) has a plurality of air pipes (31) for supplying gas to the internal spaces of the plurality of gas suppliers (10), and a manifold (35) connected to the plurality of air pipes. The gas sent to the gas suppliers (10) via the air supply unit (30) is subjected to heat exchange with wastewater in the immersed portion of the air supply unit (30), and then sent to the gas suppliers (10).SELECTED DRAWING: Figure 1

Description

It relates to an aerobic biological treatment apparatus suitable for aerobic biological treatment of organic wastewater, and in particular, a MABR (membrane aeration bioreactor) using an oxygen permeable membrane to dissolve oxygen in the water to be treated in the reaction tank. The present invention relates to an aerobic biological treatment device that employs a method.

Aerobic microbial wastewater treatment equipment is widely used as a treatment method for organic wastewater. On the other hand, the aeration using an air diffuser has a low oxygen dissolving efficiency and requires aeration at a pressure higher than the water pressure applied to the air diffuser, so the electric power cost of the blower is high.

A waste water treatment apparatus has been studied in which waste water is treated by attaching microorganisms to a gas feeder that is permeable to gas but impermeable to liquid. Since this device can suppress the pressure applied to air supply, it is possible to reduce power costs. Examples of the gas supply are disclosed in Japanese Patent Laid-Open Nos. 2003-100000 and 2000-100003.

Japanese Patent No. 3743771 Japanese Patent No. 4680504

In an aerobic microbial wastewater treatment apparatus using a gas feeder, condensed water is generated inside the gas feeder due to permeation of water vapor through the gas feeder and 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 lowered.

As a countermeasure against such condensed water, it is conceivable to provide a liquid feeding section for discharging the condensed water inside the gas supply body.

However, even if the condensed water is discharged, there is a problem that the oxygen permeation rate decreases when the condensed water adheres to the inner side of the oxygen permeable membrane. If the relationship between the temperature of the water to be treated and the supplied air is (the temperature of the water to be treated) > (the temperature of the supplied air), the temperature inside the gas supply unit will drop, and the saturated water vapor content of the internal air will decrease. and condensed water is generated. That is, even if the condensed water accumulated inside the gas supply body is drawn out through a pipe, the situation where the condensed water is generated inside the gas supply body does not change. Not yet.

The wastewater treatment system of the first aspect purifies wastewater using the action of microorganisms. The wastewater treatment system comprises a gas feed having a waterproof permeable membrane, wherein the gas supplied to the interior space of the gas feed is supplied to microorganisms in the waste water outside the waterproof permeable membrane. A gas supply body and an air supply unit for supplying gas to an internal space of the gas supply body are provided. The air supply unit has a plurality of air pipes that supply gas to the internal spaces of the plurality of gas supply bodies, and a manifold connected to the plurality of air pipes. The gas supplied to the gas supply body via the air supply part exchanges heat with the waste water in the portion of the air supply part immersed in the waste water, and then is supplied to the gas supply body. be. More specifically, the flues include both flues that supply gas to the manifold and a plurality of flues that supply gas from the manifold to the interior space of each gas supply.

A wastewater treatment system according to a second aspect is the wastewater treatment system according to the first aspect, wherein the portion of the air supply unit immersed in the wastewater has a metallic fin or projection shape.

A wastewater treatment system according to a third aspect is the wastewater treatment system according to the first aspect or the second aspect, wherein the portion of the air supply unit immersed in the wastewater is a manifold.

A wastewater treatment system according to a fourth aspect is the wastewater treatment system according to the first aspect or the second aspect, wherein the portion of the air supply unit immersed in the wastewater is an air pipe. The air pipe is more preferably an air pipe that supplies gas to the manifold.

A wastewater treatment system of a fifth aspect is the wastewater treatment system of the first aspect or the second aspect, wherein the temperature of the gas supplied to the gas supply is equal to or lower than the temperature of the wastewater, and The temperature difference of the wastewater is within 5°C.

According to the wastewater treatment system of the present disclosure, heat is exchanged by partially submerging the path of the air supply pipe in the treatment tank, and after reducing the temperature difference between the gas to be supplied and the wastewater, the inside of the gas supply body can be fed into the gas supply body, and the generation of condensed water inside the gas supply body can be suppressed.

It is the schematic diagram which added the manifold 35 to the vertical cross section of the wastewater treatment system 50 of 1st Embodiment. FIG. 2 is a vertical cross-sectional view of the wastewater treatment system 50 of the first embodiment in a direction different from that of FIG. 1 by 90°. 3 is a vertical sectional view of the gas supply body 10; FIG. 3 is a perspective view of a gas delivery layer 12 that constitutes the gas supplier 10. FIG. FIG. 4 is a diagram schematically showing a manifold 35A having plate-type fins; FIG. 4 is a diagram schematically showing a manifold 35B having corrugated fins; FIG. 4 is a diagram schematically showing how microorganisms decompose organic matter in wastewater W using a gas supplier 10. FIG. FIG. 4 is a diagram showing a state in which water is accumulated in the internal spaces of gas supply bodies 10a and 10b and is being discharged. Figure 8B shows the state of the gas supplies 10a, 10b after Figure 8A; 4 is a view showing an orifice portion 47a inside a liquid-sending pipe 41. FIG. 4 is a diagram showing an orifice portion 47b having multiple holes in a liquid-sending pipe 41. FIG. 4 is a view showing a constricted portion 47c inside a liquid-sending tube 41. FIG. 4 is a diagram showing a curved portion 47d inside a liquid-sending tube 41. FIG. 4 is a diagram showing a portion in which a communicating porous member 47e is arranged in a liquid-sending pipe 41. FIG. FIG. 3 is a diagram showing the appearance of a gas supplier 10 used in a dew condensation test; FIG. 4 is a diagram showing the inside of the gas supplier 10 used in the dew condensation test. It is the schematic diagram which added the manifold to the vertical cross section of the wastewater treatment system 50a of 2nd Embodiment. It is the schematic diagram which added the manifold 35 to the vertical cross section of the wastewater treatment system 50 of 3rd Embodiment. FIG. 13 is a vertical cross-sectional view of the wastewater treatment system 50 of the third embodiment in a direction different from that of FIG. 13 by 90°. It is the schematic diagram which added the manifold 35 to the vertical cross section of the wastewater treatment system 50 of 4th Embodiment. FIG. 15 is a vertical cross-sectional view of the wastewater treatment system 50 of the fourth embodiment in a direction different from that of FIG. 15 by 90°.

<First embodiment>
(1) Overall structure
(Wastewater treatment device 100)
The wastewater treatment apparatus 100 of this embodiment utilizes the action of aerobic microorganisms contained in wastewater to decompose at least one organic matter or nitrogen source in the wastewater to purify the wastewater. As shown in FIG. 1 , the wastewater treatment apparatus 100 includes a wastewater treatment tank 51 and a wastewater treatment 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 is provided with an inlet 51a and an outlet 51b. For example, the inflow port 51a and the outflow port 51b may be provided on the sides facing each other.

In this embodiment, the inlet 51a and the outlet 51b are always open. The wastewater W is continuously or intermittently supplied from the inflow port 51a toward the outflow port 51b disposed opposite the inflow port 51a (the dashed-dotted arrows in FIG. 2 indicate the flow rate of the wastewater W). flow).

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

(Wastewater treatment system 50)
The wastewater treatment system 50 includes a feeder unit 52 , an air feed section 30 and a liquid feed section 40 .

(Supplier unit 52)
As shown in FIG. 1 , the supply unit 52 is a unitized gas supply unit 10 and is arranged inside the wastewater treatment tank 51 . In FIG. 1, the feeder unit 52 is made up of a plurality of gas feeders 10 arranged in parallel. The feeder unit 52 is arranged such that the portions of the gas feeders 10 other than the upper end portions are immersed in the wastewater W during use.

(Gas supplier 10)
Each gas supply body 10 is a structure that supplies the gas supplied from the opening 21 b into the wastewater W while being immersed in the wastewater W of the wastewater treatment tank 51 . The gas supplier 10 includes a gas delivery layer 12 and a waterproof gas permeable membrane 21, as shown in FIG. A part of the air supply pipe 31 of the air supply unit 30 is inserted into the internal space of the gas supply member 10 via the opening 21b. A gas (air, oxygen) is supplied to the internal space of the gas supplier 10 from the air supply unit 30 . A part of the liquid feeding pipe 41 of the liquid feeding section 40 is arranged in the internal space of the gas supply body 10 . Condensed water generated in the gas delivery layer is discharged from the internal space of the gas supply body 10 to the outside via the liquid delivery section 40 . In this embodiment, the opening 21 b allows air and gas to enter and exit the internal space of the gas supplier 10 in addition to the air pipe 31 and the liquid pipe 41 . The opening 21b may be sealed so that air or gas other than the air pipe 31 and the liquid pipe 41 cannot enter or exit.

As shown in FIG. 2, each gas supplier 10 is a plate-like member, and is arranged so that its surfaces are developed along the vertical direction (depth direction) and lateral direction (horizontal direction). there is Thereby, the contact area with the waste water W is efficiently ensured. In addition, by arranging the gas supply bodies 10 so that the side surfaces of the gas supply bodies 10 are parallel to the straight line connecting the inlet 51a and the outlet 51b, the flow rate from the inlet 51a to the wastewater treatment tank 51 is reduced. The waste water W supplied inside smoothly flows toward the outflow port 51b. It should be noted that the number of gas supply bodies 10 constituting the supply body unit 52 is not necessarily plural, and may be singular. Further, the gas supply body may be spiral-shaped or hollow-fiber-shaped. In the case of a spiral shape, a gas supply member is arranged inside like a flat plate, and an air supply unit and a liquid supply unit are inserted into the gas supply unit. In the case of the hollow fiber shape, if the strength of the hollow fiber itself can hold the internal space, the gas supply may be omitted. The air feeding section and the liquid feeding section are inserted inside a header that bundles a plurality of hollow fibers.

When the interval between the gas supply bodies 10 is defined as "the interval between the outer surfaces of two adjacent gas supply bodies 10 excluding the thickness of the gas supply bodies 10", the interval between the gas supply bodies 10 is 5 mm or more and 200 mm or less. is preferably If the gap between the gas supply members 10 is less than 5 mm, there is a risk of clogging caused by microorganisms growing on the waterproof air permeable membrane 21 . If the interval between the gas supply bodies 10 exceeds 200 mm, the efficiency of contact with wastewater may be poor, making it difficult to improve the wastewater treatment performance. In order to reliably avoid the above problem, it is more preferable to set the distance between the gas supply bodies 10 to 15 mm or more and 50 mm or less.

FIG. 3 is a vertical sectional view of the gas supplier 10. As shown in FIG. As shown in FIG. 3, the gas supplier 10 includes a gas delivery layer 12 and a waterproof air permeable membrane 21. The gas delivery layer 12 is placed in a bag formed by the waterproof air permeable membrane 21. be. The bag is made by superimposing two waterproof air permeable membranes 21, 21 and adhering three ends of these waterproof air permeable membranes 21, 21, and the upper end (the gas supply in the gas delivery layer 12). side end) has an opening 21b (see FIG. 3). By inserting the gas delivery layer 12 into the inside of the bag through the opening 21 b , the outer periphery of the gas delivery layer 12 is covered with the waterproof air permeable membrane 21 . The position or shape of the opening 21b is not limited, and for example, a part of each end (including the top side, bottom side, and horizontal side (vertical line) of the bag) may be the opening.

(Air supply unit 30)
The air supply unit 30 supplies gas to the internal space of the gas supply body 10 . The air supply unit 30 includes a blower 36 , a manifold 35 and an air supply pipe 31 . The air pipe 31 is a pipe that feeds the air (oxygen) sent from the blower 36 into the gas supplier 10 . The air pipe 31 includes a portion that connects the gas supply source (here, the blower 36 ) to the manifold 35 and a portion that branches off from the manifold 35 and connects the inside of the gas supply body 10 .

A part of the air supply unit 30 is installed under the water surface of the treatment tank 51 in which the waste water W is stored. All or part of the manifold 35 and/or the flue 31 may be placed under water. In this embodiment, as shown in FIG. 1 or 2, the entire manifold 35 and part of the air pipe 31 are installed under water.

Although the material and shape of the part of the air supply unit 30 that is installed under the water surface is not limited, a material with good thermal conductivity is preferable. The heat exchange efficiency should be 70% or higher. When the manifold 35 is below the water surface as in this embodiment, the heat exchange efficiency here means the temperature of the supplied air supplied from the manifold inlet 35a and the supplied air flowing out from the manifold outlet 35b. is divided by the temperature difference between the gas supplied from the inflow port 35a and the wastewater W in the treatment tank 51 and then multiplied by 100. The material of the manifold 35 may be metal or resin. Metals may be copper, aluminum, iron, and stainless steel.

The portion of the air supply unit 30 that is installed under the water surface may be provided with fins 352 and 352a. The fins 352 may have a protrusion shape. The shape of the fins 352, 352a may be a plate type as shown in FIG. 5 or a corrugated type as shown in FIG. Fins 352 may be made of metal. The part of the air supply unit 30 installed under the water surface functions as a heat exchanger that exchanges heat between the gas flowing inside the part of the air supply unit 30 installed under the water surface and the waste water W outside. . The fins 352, 352a serve to facilitate such heat exchange.

The gas supplied into the wastewater W through the gas supply body 10 is a gas containing oxygen in order to promote the activation of aerobic microorganisms in the wastewater W. Specifically, it may be air or pure oxygen. In the illustrated example, the gas from the blower 36 is supplied to the opening 21b. From the viewpoint of keeping the manufacturing cost low, the air in the atmosphere may be directly taken into the gas supply member 10 from the opening 21b without using the blower 36. FIG.

(manifold 35)
The manifold 35, as shown in FIGS. 1 and 2, is installed under the surface of the treatment tank 51 in which the water W is stored. The manifold 35 is provided with an inflow port 35a and an outflow port 35b for supplied gas.

In this embodiment, the inlet 35a and the outlet 35b of the manifold 35 are always open. The supplied gas flows continuously or intermittently from the inflow port 35a toward the outflow port 35b.

(Waterproof air permeable membrane 21)
The waterproof air permeable membrane 21 is immersed in liquid (waste water) so that the outermost layer is in contact with the liquid (waste water), and oxygen supplied to the inside (gas delivery layer 12 side) permeates to the outside. Oxygen is supplied to the liquid (waste water) by The waterproof air-permeable membrane 21 allows air to permeate from the inside (gas delivery layer 12) to the outside (waste water W) in a state in which the gas supply body 10 is immersed in the waste water treatment tank 51, and the outside (waste water W). It has the property of being impermeable to wastewater from the inside (gas delivery layer 12). As a result, as shown in FIG. 7, the 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. Therefore, microorganisms adhere to the surface 21 a of the waterproof air permeable membrane 21 to form a biofilm 214 . Microorganisms dissolved or dispersed in water or nitrogen compounds are decomposed by the action of microorganisms contained in the waste water W or retained on the surface 21a, thereby purifying the waste water. .

Specifically, as shown in FIG. 3 , the waterproof gas permeable membrane 21 includes a base material 211 , a gas permeable non-porous layer 212 and a microorganism supporting layer 213 . In the illustrated example, the waterproof gas-permeable membrane 21 is laminated in the order of a base material 211, a gas-permeable non-porous layer 212, and a microorganism-supporting layer 213. As shown in FIG. The microbial support layer 213 is the outermost layer that contacts the wastewater W. Note that unlike the illustrated example, the waterproof air permeable membrane 21 may be one in which the gas permeable nonporous layer 212, the base material 211, and the microorganism supporting 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 having a large number of fine through holes. Materials for the substrate 211 include fluororesins including polyolefin, polystyrene, polysulfone, polyethersulfone, polyarylsulfone, polymethylpentene, polytetrafluoroethylene, and polyvinylidene fluoride, polybutadiene, and poly(dimethylsiloxane). including polymeric materials selected from silicone-based polymers, and copolymers of these materials;

The method for manufacturing the base material 211, which is a microporous membrane, is not particularly limited, but for example, the base material can be manufactured by any one of a phase separation method, a stretching opening method, a dissolution recrystallization method, a powder sintering method, a foaming method, and a solvent extraction method. Material 211 can be manufactured. Substrate 211 may also 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 measurement method.

The pore diameter of the substrate 211 is preferably 0.01 μm to 50 μm from the viewpoint of preventing defects in the gas permeable nonporous layer, and is 0.1 μm to 30 μm from the viewpoint of maintaining high strength and gas permeability. is more preferable. The pore diameter is a pore diameter obtained by observing the surface with a scanning electron microscope (SEM) and obtaining the observed image by the following method. Observation can be performed at any magnification as long as the pore size of the object to be observed can be calculated appropriately.
(Method for obtaining pore diameter)
An image obtained by SEM observation is binarized, and the pore diameter is calculated by image analysis. In the calculation, the pore diameter is approximated to an ellipse, and the average value is evaluated using the length of the long axis of the ellipse as the pore diameter.

Alternatively, the pore diameter of the base material 211 is defined as an average pore diameter obtained from pore diameter distribution measurement (perm porosimetry) by a capillary condensation method. In perm porosimetry, the relationship between the differential pressure between the atmospheric pressure and the measured pressure and the gas permeation flow rate is obtained from the gas permeation flow rate that is measured when the measurement pressure of the gas applied to the sample is gradually increased. To determine the pore size, a wet curve measured with a wet sample after immersing the sample in a wetting liquid with a known surface tension and a dry curve measured with a dried specimen are determined. By gradually increasing the pressure within a predetermined pressure range, it is possible to obtain information on the through-pore diameter in the sample. The average pore diameter is obtained by finding the point X where the wet curve and the half dry curve (half dry curve) intersect, 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 pressure difference between atmospheric pressure and gas pressure at point X (Pa). For measurement, a perm porometer (CFP-1500-AEC) manufactured by Porous Materials can be used. As test conditions, 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 is can be measured at 250 psi and the rate of differential pressure rise at 4 psi/min. When preparing a wet sample, the sample can be sufficiently wetted by putting the wetting liquid in which the sample is immersed into a desiccator and degassing it.

(Gas permeable non-porous layer 212)
The gas-permeable non-porous layer 212 is a layer that has pores with a pore diameter smaller than that of the base material, or the pore diameter cannot be detected and is permeable to gas. The pore diameter of gas permeable non-porous layer 212 can be measured by the same method as the pore diameter of substrate 211 .

Examples of the gas that permeates 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 growing and activating microorganisms, the gas is preferably oxygen or a mixed gas containing oxygen. Gas permeability can be measured by the method defined in JIS K 7126.

Gas permeable non-porous layer 212 may be a thermoplastic resin or a thermosetting resin. The thermosetting resin may be a thermosetting resin or a resin that is cured by irradiation with ultraviolet rays. It may also be a resin that cures by organic peroxide cross-linking, addition reaction cross-linking, or condensation cross-linking.

Materials for gas permeable nonporous layer 212 may include thermosetting polymers selected from polyolefins, polystyrenes, polysulfones, polyethersulfones, polytetrafluoroethylenes, acrylic resins, polyurethane resins, and copolymers of these materials. Also, silicone-based silicone resins 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 polyurethane resins include "Asaflex 825" (manufactured by Asahi Kasei Corporation), "Perethene 2363-80A", "Perethene 2363-80AE", "Perethene 2363-90A", "Perethene 2363-90AE",・Chemical Co., Ltd.) and “Heimlen Y-237NS” (manufactured by Dainichiseika Kogyo Co., Ltd.) can be used.

There are no particular restrictions on the formulation or composition of the silicone-based resin, silicone polymer, or silicone-based resin composition for obtaining them. The monomer used in the silicone-based resin composition may be monofunctional, bifunctional, trifunctional, or tetrafunctional, and may be used alone or in combination of two or more. Halogenated alkylsilanes, unsaturated group-containing silanes, aminosilanes, mercaptosilanes, epoxysilanes, and the like may be used as monomers. Examples of monomers that can be used include monomers represented by the following chemical formulas. 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 ( where " =} " 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 group, isopropyl group, butyl group, isobutyl group, tert-butyl group, hexyl group, octyl group and decyl group; An aryl group; a cycloalkyl group such as a cyclopentyl group and a cyclohexyl group; an aralkyl group such as a benzyl group, a 2-phenylethyl group and a 3-phenylpropyl group, and the like may be used. Among these, a methyl group, a phenyl group, or a combination of both is preferred. This is because a component that is 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 having particularly good solvent resistance is to be used, a combination of a methyl group, a phenyl group, or a combination of both of them and a 3,3,3-trifluoropropyl group is preferred. preferable. Further, the silicone-based resin composition may contain an organoalkoxysilane. Organoalkoxysilanes include, for example, compounds represented by the following chemical formulas, which may be used singly 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-based resin composition may contain an organosilanol. Organosilanols include, for example, compounds represented by the following chemical formulas, which may be used singly 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-based resin may include, for example, hydrolysis of chlorosilane, ring-opening polymerization of cyclic dimethylsiloxane oligomer, and the like. Examples of polymers to be used include dimethyl-based polymers, methylvinyl-based polymers, methylphenylvinyl-based polymers, and methylfluoroalkyl-based polymers.

The method of curing the silicone polymer, that is, the method of reacting (vulcanizing) to obtain the silicone resin is not particularly limited. Heat vulcanization or room temperature vulcanization may be used. Either the millable type silicone resin composition or the liquid rubber type silicone resin composition may be used as the state before the reaction. A polymer having a degree of polymerization of about 4,000 to 10,000 is preferably used for the millable type silicone resin composition. Moreover, it may be of 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 groups (Si—CH ₃ ), vinylsilyl groups (Si—CH═CH ₂ ). reaction with an organic peroxide, addition reaction between a vinylsilyl group and a hydrosilyl group (Si--H), reaction with ultraviolet rays, reaction with electron beams, and the like may be used.

(Microorganism support layer 213)
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 through. Materials for the microorganism support layer 213 include, for example, meshes, woven fabrics, non-woven fabrics, foams, 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, Fluorine resins, polyvinyl butyral resins, polyimides, polyphenylene sulfides, para- and meta-aramids, polyarylates, carbon fibers, glass fibers, aluminum fibers, steel fibers, ceramics, and the like. Polyolefin resins, polyester resins, polyamide resins, acrylic resins, polyurethane resins, and carbon fibers are preferred in consideration of microbial adhesion and workability.

The basis weight of the microorganism supporting 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 supporting layer 213 is a value measured by mass per unit area according to JIS 1913:2010 general nonwoven fabric test method 6.2. When the basis weight of the microorganism-supporting layer 213 is 2 g/m ² or more, unevenness is generated on the surface of the microorganism-supporting layer 213, so that the microorganism-supporting layer 213 can easily retain microorganisms. In addition, when the basis weight of the microorganism supporting layer 213 is 500 g/m ² or less, a space in which the microorganisms can grow is generated inside the microorganism supporting layer 213, so that the microorganisms are easily retained, and the space allows oxygen to be transferred to the microorganisms. The effect of facilitating supply can be obtained.

The thickness of the microorganism supporting 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-supporting layer 213 is a value measured according to JIS 1913:2010 General nonwoven fabric test method 6.1 Thickness measurement method.
In addition, the microorganism support layer 213 may be formed by surface treatment of the base material 211 . By doing so, the surface roughness and membrane potential of the base material 211 can be increased by the above-described surface treatment, so that the adhesion of microorganisms can be improved. For example, as the above surface treatment, graft polymerization of glycidyl methacrylate and further reaction with diethylamine or sodium sulfite can be performed. Alternatively, as the above surface treatment, after graft polymerization of glycidyl methacrylate, ammonia or ethylamine may be reacted.

(Gas delivery layer 12)
FIG. 4 is a perspective view showing the gas delivery layer 12. As shown in FIG. 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 for delivering gas supplied from the first end along the first direction. The gas from the air supply section 30 (air supply pipe 31, see FIG. 1) is supplied to the lower end portion of the gas delivery layer 12 via the air supply section 31a. The gas delivery layer 12 has a gas flow path S that delivers the supplied gas in the first direction (see the dashed line in FIG. 4), and releases the gas from the gas passage holes 13 on the side surface.

More specifically, as shown in FIG. 4, the gas delivery layer 12 has a plurality of cores 12a, a front liner 12b and a back liner 12c. The front and back surfaces of the gas delivery layer 12 are composed of a front liner 12b and a back liner 12c, which are plate-shaped members.

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

Further, each core member 12a functions as a supporting portion that supports the space between the front liner 12b and the back liner 12c so that the space between the front liner 12b and the back liner 12c does not shrink when pressed from the front liner 12b and back liner 12c sides. As shown in FIG. 1 or 2, when the gas supplier 10 is immersed in the waste water W, 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 does not shrink due to water pressure. 12c. Thereby, a sufficient amount of gas delivery can be ensured in the gas delivery layer 12 (gas flow path 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 holes 13 are through holes formed in the front liner 12b and the back liner 12c. The flowing gas is supplied into the liquid through the waterproof gas permeable membrane 21 .

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 12 b and the back liner 12 c after molding the gas delivery layer 12 . A porous sheet may be used for the front liner and the back liner. A porous sheet may be used for the gas delivery layer as long as 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, methyl cellulose resin, ethyl cellulose resin, polyvinyl alcohol resin, vinyl acetate resin, phenol resin, fluororesin and polyvinyl butyral resin) and the like.

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 superior strength.

From the viewpoint of keeping material costs low, it is preferable to use paper, resins such as polyolefin, polystyrene, vinyl chloride and polyester, and metals such as aluminum as materials for the gas delivery layer 12, for example. Also, the material cost of the gas delivery layer 12 can be kept low by using corrugated 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 shape of the holes forming the gas permeable holes of the gas delivery layer 12 can be of various shapes such as a circular shape and a polygonal shape (including a honeycomb structure). Although the shape of the hole is not particularly limited, it is preferably polygonal, and specifically rectangular or square.

(Liquid sending unit 40)
The liquid sending unit 40 has a function of discharging fluid such as water and/or gas such as air from the internal space of the gas supplier 10 to the outside. The liquid sending unit 40 has a liquid sending tube 41 , a manifold 45 and a suction pump 46 . The plurality of liquid-sending tubes 41 are connected to the internal spaces of the plurality of gas supply bodies, respectively. The manifold 45 is a pipe having a structure in which a single pipe branches into a plurality of pipes. A manifold 45 is connected to a plurality of liquid-sending tubes 41 and a suction pump 46 . A suction pump 46 is connected to the manifold 45 . The suction pump 46 is capable of sucking either liquid, gas, or a gas-liquid mixture.

The cross-sectional shape of the liquid feeding tube 41 is not particularly limited, and may be, for example, any polygonal shape such as a circle or square, or a combination of a part of a circle and a part of a polygon such as a D-shaped cross section. . The cross-sectional area of the inner diameter is preferably 0.1 mm ² or more and 100 mm ² or less, and more preferably 0.5 mm ² or more and 10 mm ² or less from the viewpoint of increasing the degree of freedom of the suction pump. Moreover, from the viewpoint of obtaining a sufficient drainage flow rate, it is more preferably 1 mm ² or more and 4 mm ² or less.

(Occurrence of pressure loss, pressure loss generating portion 47)
The liquid feed pipe 41 has a function of generating pressure loss. The pressure loss may be generated by having the entire liquid sending pipe 41 have a narrow flow path, or the liquid sending pipe 41 may have a pressure loss generating portion 47 as a part where a particularly high pressure loss occurs. may be

The pressure loss generating portion 47 is a portion where flow pressure loss occurs due to gas flow. The pressure loss generating portion 47 may have various forms. The pressure loss generating part 47 is the orifice part 47a, 47b (FIGS. 9A and 9B) in the liquid feeding pipe, or the constricted part 47c (FIG. 9C) in the liquid feeding pipe 41. It may be a curved portion 47d (FIG. 9D), or a portion where a communicating porous member 47e (FIG. 9E) in the liquid feeding pipe 41 is arranged. The orifice portions 47a and 47b are shapes having a thin wall with a hole in the inside of the liquid feeding tube. A perforated plate may be installed inside the liquid feeding pipe 41 . The number of holes in the orifice site may be one (Fig. 9A) or many (Fig. 9B).

(Operation of liquid sending unit)
In the wastewater treatment system 50 of the present embodiment, condensed water is generated in the internal space of the gas supply body 10, and unless this is removed, a part of the air supply gas flow path may be clogged and the air supply efficiency may decrease. be.

8A, 8B disclose a portion of the wastewater treatment system 50 of the present disclosure. That is, the gas supply bodies 10a and 10b and the liquid delivery section 40 are disclosed. FIG. 8A shows a state in which liquid (water) is accumulated in the internal spaces of the gas supply bodies 10a and 10b. The amount of water accumulated in the internal spaces of the gas suppliers 10a, 10b is different, as shown in FIG. 8A. In such a case, the wastewater treatment system 50 of the present embodiment drains the internal spaces of the gas supply bodies 10a and 10b by the liquid sending section 40. FIG. That is, the operation of the suction pump 46 creates a negative pressure in the manifold 45, and the liquid is discharged from the gas supply bodies 10a and 10b.

In this way, when the liquid supply unit 40 continues to drain the liquid, as shown in FIG. 8B, all the liquid (water) is discharged from the gas supply body 10b in which the amount of water initially accumulated was small. In such a state, the gas in the internal space is discharged from the gas supply body 10a, and the flow of the gas (higher speed than the discharge of the liquid) causes flow pressure loss. Due to the pressure loss, the negative pressure in the manifold 45 is maintained, and liquid continues to be discharged from the gas supply body 10b in which liquid remains. In the design stage, adjustment of the ability of the suction pump 46 and adjustment of the structure of the liquid feeding section 40 (adjustment of the generated pressure loss) are performed in advance so that a negative pressure equal to or greater than the head pressure difference of the liquid is generated. there is

In this embodiment, it is preferable that the amount of gas supplied to the internal space of the gas supply body 10 through the air pipe 31 is larger than the amount of gas exhausted through the liquid feed pipe 41 . In that case, even when the suction pump 46 is in operation, the pressure in the internal space of the gas supplier 10 is about atmospheric pressure. Moreover, the wastewater treatment system 50 has a mechanism that prevents the pressure in the internal space of the gas supply body 10 from greatly varying from the atmospheric pressure. In this embodiment, the wastewater treatment system 50 preferably has a mechanism for exhausting the internal space of the gas supplier 10 (including exhaust from the opening 21b) in addition to the liquid transfer pipe 41.

Similarly, when the number of gas supply bodies 10 is three or more, the liquid is discharged sequentially from the gas supply body 10 with the smallest amount of water initially accumulated, and the discharge of the entire water is completed.
In the wastewater treatment system 50 of this embodiment, the pressure in the manifold 45 is reduced precisely because of the pressure loss generating section 47 . Without the pressure loss generating part 47, in the state of FIG. 8B, air is preferentially sucked from the gas supply body 10b that has finished draining liquid, the negative pressure in the manifold 45 is no longer maintained, and liquid remains. Liquid cannot be drained from the gas supplier 10a. According to the present disclosure, by causing pressure loss, it is possible to continue draining the other gas supplier 10a even after the gas supplier 10b has finished draining.

<Condensation test>
An experiment was conducted to compare the state of dew condensation inside the gas supply by immersing the gas supply in water and supplying air of different temperatures to the gas supply. Experiment 1 is a case where air having a temperature equivalent to that of water was supplied to the gas supply. Experiment 2 is a case where air having a temperature lower than the temperature of water is supplied to the gas supply.
In both cases the gas supply 10 shown in FIGS. 10 and 11 was used. The gas supply body 10 has a bag-shaped waterproof air permeable membrane 21 and a gas delivery layer 12 arranged therein. An air pipe 101 for introducing gas inside and an exhaust port 102 for discharging gas are provided on the upper part of the waterproof air permeable membrane 21 . The experiment was conducted by holding the gas supplier 10 in a water tank so that the portion below the line 103 shown in FIG. 10 was submerged in water.

(Experiment 1)
In Experiment 1, the temperature of the water bath is 70°C, and the temperature of the introduced air is also 70°C. The flow rate of the introduced air is 10 L/min. Air was introduced continuously for 3 hours. The total amount of permeated water vapor at 70° C. for 3 hours is about 27 g.
After the experiment, the weight of the gas supplier 10 was measured and compared with the weight of the gas supplier 10 previously measured before the experiment, and no weight change was observed. Further, as shown in FIG. 11, the state of dew condensation inside the gas supply body 10 was examined, but no dew condensation occurred. Therefore, the amount of condensed water is 0 g. When the ratio of condensed water to permeated water vapor was calculated, it was 0/27*100=0%.

(Experiment 2)
In Experiment 2, the temperature of the water bath was set at 70°C, and the temperature of the introduced air was set at 25°C. The flow rate of the introduced air is 10 L/min. Air was introduced continuously for 3 hours. The total amount of permeated water vapor at 70° C. for 3 hours is about 27 g, which is the same as Experiment 1.

After the experiment, the weight of the gas supply member 10 was measured and compared with the weight of the gas supply member 10 that had been measured before the experiment. is. Further, as shown in FIG. 11, when the state of dew condensation inside the gas supplier 10 was examined, it was found that dew condensation occurred in the dew condensation portion 110 . The ratio of condensed water to permeated water vapor was calculated to be 0.4/27*100=1.5%.

Comparing the results of Experiments 1 and 2, the effect of suppressing dew condensation by supplying heated air to the gas supply body is obvious. Thus, the wastewater treatment system 50 of the present disclosure can reduce condensation within the gas supply as the manifold 35 is immersed in the wastewater where the air is heated by the wastewater.

<Second embodiment>
As shown in FIG. 12, the wastewater treatment system 50a of the present embodiment includes an air supply section 30a and a liquid supply section 40a. Others are the same as the wastewater treatment system 50 of the first embodiment. That is, when supplying air (oxygen) to the internal space of the gas supply body, the blower 36 is used to supply the air. Conversely, when discharging the fluid in the internal space of the gas supplier 10, the suction pump 46 is operated to discharge the fluid. That is, each is performed intermittently. Also in this case, similarly to the first embodiment, the wastewater treatment system 50a preferably has a mechanism that prevents the pressure in the internal space of the gas supply body 10 from greatly varying from the atmospheric pressure.

<Third Embodiment>
The wastewater treatment apparatus 100 or wastewater treatment system 50 of this embodiment is the same as the wastewater treatment apparatus 100 or wastewater treatment system 50 of the first embodiment except for the configuration of the air supply unit 30 .

13 and 14 show configurations of a wastewater treatment apparatus 100 and a wastewater treatment system 50 of the third embodiment. In the first embodiment, the entire manifold 35 is below the water surface, whereas in the third embodiment, a portion of the manifold 35 is below the water surface. With such a configuration, the gas supplied to the gas supply body 10 via the air supply unit 30 is heat-exchanged with the waste water W, thereby suppressing the generation of condensed water inside the gas supply body.

<Fourth Embodiment>
The wastewater treatment apparatus 100 or wastewater treatment system 50 of this embodiment is the same as the wastewater treatment apparatus 100 or wastewater treatment system 50 of the first embodiment except for the configuration of the air supply unit 30 .

15 and 16 show configurations of a wastewater treatment apparatus 100 and a wastewater treatment system 50 of the fourth embodiment. While in the first embodiment the manifold 35 is below the water surface, in the fourth embodiment the manifold 35 is above the water surface. In the fourth embodiment, part of the air pipe 31 is under water. With such a configuration, the gas supplied to the gas supply body 10 via the air supply unit 30 is heat-exchanged with the waste water W in the air supply pipe 31, thereby suppressing the generation of condensed water inside the gas supply body. do.

Although embodiments of the present disclosure have been described above, it will be appreciated that various changes in form and detail may be made without departing from the spirit and scope of the present disclosure as set forth in the appended claims. .

10 gas supply 12 gas air layer 21 waterproof air permeable membranes 30, 30a air supply unit 31 air supply pipe 35 (air supply unit) manifold 36 air supply pumps 40, 40a liquid supply unit 41 liquid supply pipe 45 (liquid supply unit ) manifold 46 suction pumps 50, 50a wastewater treatment system 51 wastewater treatment tank 52 supply units 100, 100a wastewater treatment equipment

Claims (5)

A wastewater treatment system that purifies wastewater using the action of microorganisms,
a plurality of gas suppliers having waterproof permeable membranes, wherein the gas supplied to the interior space of the gas suppliers is supplied to the microorganisms in the wastewater outside the waterproof permeable membranes;
an air supply unit that supplies gas to the internal space of the gas supply body;
with
The air supply unit is
a plurality of air pipes for supplying gas to the internal space of the plurality of gas supply bodies;
a manifold connected to the plurality of air pipes;
has
The gas supplied to the gas supply body via the air supply part exchanges heat with the waste water in the portion of the air supply part immersed in the waste water, and then is supplied to the gas supply body. Ru
Wastewater treatment system. 2. The wastewater treatment system according to claim 1, wherein the part of said air supply part immersed in wastewater has a shape of metal fins or projections. 3. The wastewater treatment system according to claim 1, wherein the portion of said air supply unit immersed in wastewater is a manifold. 3. The wastewater treatment system according to claim 1, wherein the part of said air supply part immersed in waste water is an air pipe. The temperature of the gas supplied to the gas supply is lower than the temperature of the wastewater, and the temperature difference between the gas and the wastewater is within 5°C.
A wastewater treatment system according to claim 1 or 2.

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