JP2020028837A - Waste water treatment apparatus - Google Patents

Abstract

To provide a waste water treatment apparatus capable of improving energy saving performance.SOLUTION: A waste water treatment apparatus 50 for treating an organic matter by action of aerobic microorganisms and anaerobic microorganisms included in waste water W stored inside a waste water treatment tank 51, includes a bag-shaped gas permeable membrane 21 provided in the waste water treatment tank 51, and having a surface where aerobic microorganisms grow by taking gas containing oxygen in the atmosphere from an opening 21b projecting from the water surface of the waste water W, and a blower 41 for sending air into a space over the opening 21b of the gas permeable membrane 21.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wastewater treatment device using microorganisms. More specifically, the present invention relates to a wastewater treatment device with improved energy saving performance.

  BACKGROUND ART In recent years, wastewater treatment apparatuses that purify wastewater by decomposing organic substances in water by utilizing the action of aerobic microorganisms have been developed. In such a wastewater treatment apparatus, in order to supply a gas containing oxygen, such as air, to aerobic microorganisms contained in wastewater, a membrane or a sheet that transmits gas and does not transmit liquid is used.

  For example, Patent Document 1 discloses a bioreactor including a treatment tank and a gas-permeable hollow fiber membrane installed in the treatment tank and used for wastewater treatment and sewage treatment. On the outer surface of the hollow fiber membrane, a biofilm utilizing gas supplied to the inside of the hollow fiber membrane is formed.

JP 2006-101805 A

  In a conventional wastewater treatment apparatus exemplified in Patent Literature 1 and the like, a compressor, a blower, and the like are used to send a gas containing oxygen such as air to a biofilm. The air is supplied to the hollow fiber membrane in the processing tank through a pipe or the like. The hollow fiber membrane forms a closed flow path, and the air supplied to the hollow fiber membrane is released as bubbles into wastewater. The reason why a compressor or a blower is used is that the hollow fiber membrane has a thin tubular shape, and it is difficult for air to flow into the hollow fiber unless air is supplied by a compressor.

  Since the compressor or blower compresses the air and sends the air, the power consumption is high and the operating cost of the device increases. Since air is supplied through pipes, compressors and blowers are required to have the ability to compress air more than the pressure loss of pipes. As the scale of a wastewater treatment apparatus increases and the number of hollow fiber membranes provided in the apparatus increases, higher compression performance or a larger number of installed compressors and blowers are required. Piping work is also complicated.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a wastewater treatment apparatus with improved energy saving performance.

  To achieve the above object, the present invention includes the subjects described in the following sections.

(Claim 1)
A wastewater treatment device for treating organic substances by the action of aerobic microorganisms contained in wastewater stored in a wastewater treatment tank,
A bag-shaped gas permeable membrane, which is provided in the wastewater treatment tank and has a surface for taking in gas containing oxygen in the atmosphere from an opening protruding from the surface of the wastewater, and having a surface on which the aerobic microorganisms proliferate,
A blower that blows air into a space above the opening of the gas permeable membrane,
A wastewater treatment device comprising:
(Claim 2)
Item 2. The wastewater treatment device according to Item 1, further comprising a lid that covers the space above the opening.
(Claim 3)
Item 3. The wastewater treatment device according to item 1 or 2, further comprising a partition that partitions the space above the opening.
(Claim 4)
The partition, a space above the opening of the gas permeable membrane,
A first space directly blown by the blower,
A second space that is supplied with air through the first space and a bag-shaped space in the gas permeable membrane;
Item 4. The wastewater treatment device according to Item 3, which is divided into:
(Claim 5)
Item 5. The wastewater treatment device according to any one of Items 1 to 4, wherein the bag-shaped gas permeable membrane has the opening at one end and the other end closed.
(Claim 6)
A gas supply comprising the gas permeable membrane and a gas passage layer, further provided in the wastewater treatment tank,
Item 6. The wastewater treatment apparatus according to any one of Items 1 to 5, wherein the gas containing oxygen that has passed through the gas permeable membrane from the gas permeable layer is transmitted through the gas permeable membrane and supplied to the wastewater.
(Claim 7)
Item 7. The wastewater treatment apparatus according to Item 6, wherein a gas flow path in a water depth direction and a gas flow path in a horizontal direction are provided inside the gas supply body.
(Claim 8)
Item 8. The wastewater treatment apparatus according to any one of Items 1 to 7, wherein one blower blows air into the space above the openings of the plurality of gas permeable membranes.

  According to the present invention, it is possible to provide a wastewater treatment apparatus with improved energy saving performance.

It is a vertical sectional view which meets an AA line of a wastewater treatment device concerning one embodiment of the present invention. It is a horizontal sectional view which meets a BB line of a wastewater treatment device concerning one embodiment of the present invention. It is a vertical sectional view which meets CC line of the wastewater treatment equipment concerning one embodiment of the present invention. It is a vertical sectional view of a gas supply object arranged in a wastewater treatment device. It is a horizontal sectional view of a gas supply object arranged in a wastewater treatment device. It is a schematic diagram which shows a mode that a gas passage layer is inserted in the inside of the bag formed from the gas permeable membrane. FIG. 5 is a perspective view illustrating a gas passage layer included in the gas supply body of FIG. 4.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that, in the following description and drawings, the same reference numerals denote the same or similar components, and thus redundant description of the same or similar components will be omitted.

  The wastewater treatment apparatus according to the present invention treats organic matter contained in wastewater by the action of aerobic microorganisms contained in wastewater stored in a wastewater treatment tank. Aerobic microorganisms grow on the surface of the gas permeable membrane.

(Wastewater treatment device 50)
FIG. 1 is a vertical sectional view taken along line AA of a wastewater treatment apparatus according to one embodiment of the present invention. FIG. 2 is a horizontal cross-sectional view of the wastewater treatment apparatus according to one embodiment of the present invention, taken along line BB. FIG. 3 is a vertical sectional view of the wastewater treatment apparatus according to one embodiment of the present invention, taken along line CC.

  As shown in FIGS. 1 to 3, the wastewater treatment device 50 of the present embodiment includes a bag-shaped gas permeable membrane 21 and a blower 41. The gas permeable membrane 21 is provided in the wastewater treatment tank 51 so that a portion other than the opening 21b is immersed in the wastewater W.

  The gas permeable film 21 takes in gas (for example, oxygen) in the atmosphere from an opening 21b protruding from the water surface. The oxygen that has passed through the gas permeable membrane 21 is supplied to the wastewater W stored in the wastewater treatment tank 51. Thereby, aerobic microorganisms proliferate on the surface of the gas permeable membrane 21, and the aerobic microorganisms in the wastewater W are activated. The opening 21b is provided at one end of the gas permeable membrane 21, and the other end located in the wastewater W is closed.

  The gas permeable membrane 21 is preferably provided in the gas supply 10 including the gas passage layer 12. The gas passage layer 12 has an arbitrary configuration, is installed inside the gas supply body 10, and holds an internal space S for taking in air.

  In the present embodiment, the wastewater W is supplied from the upper part of the wastewater treatment tank 51, is treated by aerobic microorganisms on the surface of the gas permeable membrane 21 until the water quality satisfies the discharge standard, and is discharged as treated water T.

  The blower 41 blows air into a space above the opening 21 b of the gas permeable membrane 21. Since air is sent without using a pipe that causes a pressure loss, it is not necessary to use a configuration (that is, a compressor) for compressing and sending gas such as a compressor or a blower. For this reason, it becomes possible to operate the wastewater treatment device with more energy saving as compared with the case where a blower is used.

  The wastewater treatment apparatus 50 can further include a lid 43 that covers a space above the opening 21b to which the blower 41 blows air. Thereby, it is possible to more reliably supply the gas to the gas permeable membrane 21.

  The wastewater treatment apparatus 50 can further include a partition 45 that partitions a space above the opening 21b into which the blower 41 blows air. Thereby, it is possible to more reliably supply the gas to the gas permeable membrane 21.

  Hereinafter, the configuration of the wastewater treatment device 50 will be described more specifically.

(Wastewater treatment tank 51)
As shown in FIGS. 1 to 3, the wastewater treatment tank 51 is a bottomed container capable of storing the wastewater W, and has an inlet 51 a through which the wastewater W flows in and an outlet 51 b through which the wastewater W flows out. Have.

  In the present embodiment, the inflow port 51a and the outflow port 51b are always open. The wastewater W is supplied continuously or intermittently from the inflow port 51a to an outflow port 51b arranged at a position facing the inflow port 51a.

  A baffle plate 53 can be provided in the wastewater treatment tank 51. The baffle plate 53 is provided on the upstream side of the gas supply body 10 in the wastewater treatment tank 51 and regulates the flow of the wastewater W. By providing the baffle plate 53 in the wastewater treatment tank 51, the wastewater W can flow under the wastewater treatment tank 51, and the wastewater W desirably flows through the entire wastewater treatment tank 51.

The volume of waste water treatment tank 51 is not particularly limited, for example, as long as 1 m ³ or more 10,000 m ³ or less of the volume. Exemplarily, in the present embodiment, the effective water depth of the wastewater treatment tank 51 is about 1.8 m.

(Gas supply body 10)
As shown in FIGS. 1 to 3, when the wastewater treatment device 50 is used, a plurality of gas supply bodies 10 are arranged inside the wastewater treatment tank 51. Each gas supply body 10 is a structure that supplies the gas supplied from the opening 21b into the wastewater W in a state where the portion excluding the upper end portion is immersed in the wastewater W of the wastewater treatment tank 51. The gas supplied into the wastewater W via the gas supply body 10 is a gas containing oxygen (for example, air). In the present embodiment, the air in the vicinity of the opening 21b is introduced into the opening 21b, so that the air is supplied into the wastewater W without using an aeration device. As a result, the aerobic microorganisms in the wastewater W are activated, and the sludge substances dissolved or dispersed in the water are decomposed by the activity of the microorganisms, and the wastewater is purified.

  Each gas supply body 10 is a hollow plate-shaped member. Each gas supply body 10 is arranged so that its surface is developed in the vertical direction (depth direction) and the horizontal direction (horizontal direction) in order to efficiently secure the contact area with the wastewater W. .

  FIG. 4 is a vertical sectional view of the gas supply body 10, and FIG. 5 is a horizontal sectional view of the gas supply body. FIG. 6 is a schematic view showing a state in which a gas passage layer is inserted into a bag formed of a gas permeable membrane.

  The gas supply body 10 includes a gas passage layer 12 and a gas permeable membrane 21. The gas passage layer 12 is disposed in a bag inside 21 a constituted by the gas permeable membrane 21. The bag is formed by stacking two gas permeable membranes 21 and 21 and bonding the three ends 21c of the peripheral edges of the gas permeable membranes 21 and 21 to the upper end (the gas in the gas passage layer 12). An opening 21b is provided at the end on the supply side. When the gas passage layer 12 is inserted into the bag through the opening 21b, the outer periphery of the gas passage layer 12 is covered with the gas permeable film 21. The position or shape of the opening 21b is not limited, and for example, a part of each end of the bag (including the top side, bottom side, and side (vertical line)) may be an opening.

  It is preferable that each gas supply body 10 is arranged so that these side surfaces are substantially parallel. As in the wastewater treatment apparatus 50 of the present embodiment, when the inflow port 51a and the outflow port 51b are provided in the wastewater treatment tank 51, when the flow of the wastewater W occurs, each gas supply body 10 More preferably, they are arranged in a direction that does not block the flow. In particular, when the inflow port 51a and the outflow port 51b are arranged to face each other, each side of each gas supply body 10 is parallel to a straight line connecting the inflow port 51a and the outflow port 51b. Preferably, a gas supply 10 is provided. By doing so, the wastewater W supplied from the inlet 51a into the wastewater treatment tank 51 flows smoothly toward the outlet 51b.

  When the interval between the gas supply units 10 is defined as the interval between the outer surfaces of two adjacent gas supply units 10 that does not include the thickness of the gas supply unit 10, the lower limit of the interval between the gas supply units 10 is 5 mm or more. Is preferred. The upper limit of the interval between the gas supply bodies 10 is preferably 200 mm or less. If the distance between the gas supply bodies 10 is less than 5 mm, clogging may occur due to microorganisms growing on the gas permeable membrane 21. If the interval between the gas supply bodies 10 exceeds 200 mm, the contact with the wastewater may be deteriorated. In order to avoid the above problem, the lower limit of the distance between the gas supply units 10 is more preferably 15 mm or more, and the upper limit of the distance between the gas supply units 10 is more preferably 50 mm or less.

  The length of the gas supply body 10 in the up-down direction (the depth direction at the time of immersion) is preferably 0.6 m or more and 4 m or less. The fact that the vertical length of the gas supply body 10 is 0.2 m or more is advantageous in that the effect of improving the wastewater treatment performance by improving the installation area of the gas supply body 10 per installation area of the wastewater treatment tank 51 is obtained. preferable. In this respect, the vertical length of the gas supply body 10 is more preferably 0.8 m or more, and further preferably 1.2 m or more. Further, it is preferable that the length of the gas supply body 10 in the vertical direction is 4 m or less from the viewpoints of more effectively obtaining the effect of improving the wastewater treatment ability by ventilating the gas supply body 10 and the ease of installation. From this viewpoint, more preferably, the length of the gas supply body 10 in the vertical direction is 3 m or less.

  The length of the gas supply body 10 in the horizontal direction perpendicular to the vertical direction is preferably 0.2 m or more and 3.6 m or less. It is preferable that the length of the gas supply body 10 in the horizontal direction perpendicular to the vertical direction is 0.2 m or more, since the contact area with the wastewater W is efficiently secured and the wastewater treatment efficiency is improved. It is preferable that the length of the gas flow path S in the horizontal direction is 3.6 m or less in terms of easy maintenance of strength of the entire gas supply body 10 and ease of installation of the gas supply body 10. From the above viewpoint, the length of the gas supply body 10 in the horizontal direction perpendicular to the vertical direction is more preferably 0.4 m or more and 1.8 m or less.

(Gas passage layer 12)
FIG. 7 is a perspective view showing the gas passage layer 12. The gas passage layer 12 is a hollow plate-shaped member, and is formed of any of paper, resin, metal, and inorganic material. The gas passage layer 12 is a structure having a gas passage S through which the gas supplied from the first end passes along the first direction (the direction indicated by the two-dot chain line in FIG. 7). The air near the opening 21b is supplied to the upper end of the gas passage layer 12 via the opening 21b (FIG. 4). The gas passage layer 12 has a gas passage S through which the gas supplied to the upper end passes in the first direction, and discharges the gas from the gas passage hole 13 on the side surface.

  More specifically, as shown in FIG. 7, the gas passage 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 passage layer 12 are constituted by a front liner 12b and a back liner 12c which are plate-shaped members.

  The plurality of core members 12a extend in the first direction, and are arranged at predetermined intervals in a direction orthogonal to the first direction. When the plurality of core members 12a are sandwiched between the front liner 12b and the back liner 12c, the space between the front liner 12b and the back liner 12c is partitioned by the core member 12a, and the plurality of gas passages are formed. S is formed.

  Each core member 12a functions as a supporting portion that supports the space between the front liner 12b and the back liner 12c so as not to be reduced when pressed from the front liner 12b and the back liner 12c. When the gas supply body 10 is immersed in the wastewater W as shown in FIGS. 1 to 3, the space between the front liner 12 b and the back liner 12 c is held by the core material 12 a, and thus the gas flow path is increased. The cross-sectional area of S is prevented from being reduced by the water pressure. Thereby, a sufficient amount of gas passing through the gas passage layer 12 (gas flow path S) is ensured.

  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 gas flowing through the gas passage S is supplied into the wastewater W through the gas permeable membrane 21 by the gas passage hole 13 communicating the gas passage S with the gas permeable membrane 21.

  In addition, for example, the gas passage hole 13 is formed when the gas passage layer 12 is formed. Alternatively, the gas passage holes 13 may be formed by processing the front liner 12b and the back liner 12c after the formation of the gas passage layer 12. Further, a porous sheet may be used as the front liner 12b or the back liner 12c. If sufficient gas supply performance is obtained, a porous sheet may be used as the gas passage layer 12. Further, the gas permeable holes 13 may be formed in a direction intersecting the gas flow path S (horizontal direction with respect to the surface of the wastewater W) (not shown). In this case, it is also possible to form a gas passage hole 13 in each core material 12a and provide a flow path for allowing gas to pass in the horizontal direction.

  Examples of the material of each member constituting the gas passage layer 12 include paper, ceramic, aluminum, iron, and plastic (polyolefin resin, polystyrene resin, polyester resin, polyvinyl chloride resin, acrylic resin, urethane resin, epoxy resin, polyamide resin, Methylcellulose resin, ethylcellulose resin, polyvinyl alcohol resin, vinyl acetate resin, phenol resin, fluororesin and polyvinyl butyral resin).

  The material of the gas passage layer 12 is preferably paper, aluminum, iron, a polyolefin resin, a polystyrene resin, a PVC resin, or a polyester resin because of its excellent strength.

  From the viewpoint of reducing material costs, it is preferable to use, for example, paper, resins such as polyolefin, polystyrene, polyvinyl chloride, polyester, and metals such as aluminum as the material of the gas passage layer 12. Also, by using a corrugated cardboard formed so that the gas flow path S extends in the first direction (see a two-dot chain line in FIG. 7) as the gas passage layer 12, the material cost of the gas passage layer 12 can be reduced. be able to.

  The shape of the gas passage holes 13 of the gas passage layer 12 can be various shapes such as a circular shape and a polygonal shape (including a honeycomb structure). In addition, it is preferable that the shape of the gas passage hole 13 is a polygonal shape, and it is more preferable that the shape is a rectangle or a square.

  The length in the up-down direction (depth direction at the time of immersion) of the gas flow path S formed in the gas passage layer 12 may be 20% or more and 100% or less of the length of the gas supply body 10 in the up-down direction. preferable. When the length of the gas flow path S in the vertical direction is 20% or more of the length of the gas supply body 10 in the vertical direction, the maintenance of the gas flow path S and the ventilation of the gas flow path S are facilitated, and the wastewater is discharged. It is preferable from the viewpoint of improving the processing ability. In this respect, the vertical length of the gas flow path S is more preferably 50% or more of the vertical length of the gas supply body 10, and more preferably the vertical length of the gas supply body 10. 70% or more. Further, the fact that the vertical length of the gas flow path S is 100% or less of the vertical length of the gas supply body 10 is that the effect of improving the wastewater treatment performance by ventilating the gas flow path S is better. It is preferable in terms of ease of installation and the like.

  The length of the gas flow path S in the horizontal direction perpendicular to the vertical direction is preferably 20% or more and 100% or less of the length of the gas supply body 10 in the horizontal direction perpendicular to the vertical direction. The fact that the horizontal length of the gas flow path S is at least 20% of the horizontal length orthogonal to the vertical direction of the gas supply body 10 means that the contact area with the waste water W is efficiently secured and the waste water It is preferable in that the processing efficiency is improved. The fact that the horizontal length of the gas flow path S is equal to or less than 20% of the horizontal length perpendicular to the vertical direction of the gas supply body 10 means that the strength of the entire gas supply body 10 can be easily maintained and the gas supply body can be maintained. 10 is preferable in terms of ease of installation. From the above viewpoint, the horizontal length of the gas flow path S is more preferably 40% or more and 100% or less of the horizontal length orthogonal to the vertical direction of the gas supply body 10.

  The ratio of the length Lw of water contact with the wastewater W to the length Ls of the gas flow path S may be, for example, 80% or more and 99% or less (see FIG. 1 for the lengths Ls and Lw). It is preferable that the ratio of the water contact length Lw with respect to the length Ls is equal to or larger than the lower limit value in that the amount of oxygen supplied from the gas flow path S is sufficiently secured and the wastewater treatment efficiency is improved. It is preferable that the ratio of the water contact length Lw to the length Ls is equal to or less than the upper limit value in order to prevent the wastewater W from entering the gas flow path S.

  Alternatively, in order to prevent the wastewater W from entering the gas flow path S, the water contact length Lw is set such that the water surface of the wastewater W is separated from the opening 21b of the gas supply body 10 (gas permeable membrane 21) by 2 cm or more. You may.

(Gas permeable membrane 21)
The gas permeable membrane 21, while immersed in the liquid (wastewater W) so that the outermost layer is in contact with the liquid (wastewater W), transfers oxygen from the inside (gas passage layer 12) to the outside (wastewater W). It has the property of permeating and preventing permeation of wastewater from the outside (wastewater W) to the inside (gas passage layer 12).

  As shown in FIG. 4, the gas permeable membrane 21 includes a substrate 211, a gas permeable non-porous layer 212, and a microorganism support layer 213. In the illustrated example, the gas permeable membrane 21 is laminated in the order of the microorganism support layer 213, the substrate 211, and the gas permeable non-porous layer 212, and the substrate 211 is covered with the gas permeable non-porous layer 212, The outermost layer in contact with the wastewater W is constituted by the microorganism support layer 213. The gas permeable membrane 21 may be a layer in which a substrate 211, a gas-permeable nonporous layer 212, and a microorganism supporting layer 213 are laminated in this order (as opposed to the illustrated example, the substrate 211 (May be located inside the non-porous layer 212). Also in this case, the substrate 211 can be covered with the gas-permeable non-porous layer 212, and the outermost layer in contact with the wastewater W can be constituted by the microorganism supporting layer 213.

(Base material 211)
The substrate 211 is a microporous film formed of a thermoplastic resin (the microporous film is a film provided with a large number of fine through holes). Examples of the material of the base material 211 include polyolefin, polystyrene, polysulfone, polyethersulfone, polyarylsulfone, polymethylpentene, polytetrafluoroethylene, and fluororesins including polyvinylidene fluoride, polybutadiene, and poly (dimethylsiloxane). It may include a polymer material selected from silicone-based polymers and copolymers of these materials, and the like.

  The method for producing the substrate 211, which is a microporous film, is not particularly limited. The material 211 can be manufactured. Further, the substrate 211 may be a self-assembled honeycomb microporous film.

  The thickness of the substrate 211 is preferably 10 μm or more and 500 μm or less, and more preferably 50 μm or more and 200 μm or less. The thickness of the substrate 211 is a value measured by JIS 1913: 2010 General Nonwoven Fabric Test Method 6.1 Thickness measuring method.

  The pore diameter of the substrate 211 is preferably 0.01 μm or more and 50 μm or less from the viewpoint of preventing defects in the gas permeable membrane, and 0.1 μm or more and 30 μm or less from the viewpoint of maintaining high strength and gas permeability. Is more preferred. 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. The observation magnification can be any magnification as long as the pore diameter of the object to be observed can be appropriately calculated.

<Method for determining pore size>
The image obtained by the SEM observation is subjected to a binarization process, and the pore diameter is calculated by image analysis. At the time of calculation, the pore diameter is approximated by an ellipse, and the average value is evaluated using the length of the major axis of the ellipse as the pore diameter.

(Gas permeable non-porous layer 212)
The gas-permeable non-porous layer 212 is a layer that has pores having a smaller pore diameter than the pores of the base material, or is a layer that cannot detect the diameter of the pores visually and is permeable to gas. The pore size of the gas-permeable non-porous layer 212 can be measured in the same manner as the pore size of the substrate 211.

  The gas-permeable non-porous layer 212 is a layer that can transmit oxygen, carbon dioxide, nitrogen, hydrogen, alcohols such as methanol and ethanol, organic solvents, or a mixed gas thereof. The gas permeability of the layer 212 can be measured by a method specified in JIS K 7126.

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

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

  As the above-mentioned polyurethane resin, "Asaflex 825" (manufactured by Asahi Kasei Corporation), "Pelecene 2363-80A", "Pelecene 2363-80AE", "Pelecene 2363-90A", "Pelecene 2363-90AE", (Dowau) Chemical Co., Ltd.) and "Heimlen Y-237NS" (Dainichi Seika Kogyo Co., Ltd.) can be used.

  Examples of the silicone resin include "Shiraseal 3FW", "Shiraseal DC738RTV", "DC3145", and "DC3140" (both manufactured by Dow Corning), "ELASTOSIL RT707W", "ELASTOSIL EL4300", "NC1910" (Asahi Kasei Wacker) Silicone), "SD4584PSA", "KS-847T", "KF-2005", "X-40-3237", and "KNS-3002" (manufactured by Shin-Etsu Chemical Co., Ltd.). A catalyst may be further added to the silicone resin. As the catalyst, an organic acid salt such as zinc octylate, iron octylate, cobalt and tin, and an amine-based catalyst can be used. Further, an organic tin compound, an organic titanium compound, and a platinum compound can also be used. For example, "CAT-PL-50T" (manufactured by Shin-Etsu Chemical Co., Ltd.) can be used as the catalyst. At the time of coating, a solvent such as toluene or xylene may be added.

  The method for producing the gas-permeable nonporous layer 212 is not particularly limited, and a reverse roll coater, a forward rotation roll coater, a gravure coater, a knife coater, a rod coater, a slot orifice coater, an air doctor coater, a kiss coater, a blade coater, and a cast coater The gas permeable non-porous layer 212 can be manufactured by a method using a spray coater, a spin coater, an extrusion coater, a hot melt coater, or the like. Further, the gas-permeable non-porous layer 212 can be manufactured by a method such as powder coating and electrodeposition coating. Coating may be performed by immersing the base material in the raw material liquid of the gas permeable membrane. The substrate may be in the form of a sheet or a hollow fiber. In the pre-coating process, pre-treatment such as primer coating and corona treatment may be performed.

The basis weight of the gas-permeable nonporous layer 212 is preferably 10 g / m ² or more and 500 g / m ² or less, and more preferably 20 g / m ² or more and 200 g / m ² or less. The basis weight of the gas-permeable non-porous layer 212 is based on the basis weight E (g / m ² ) of the substrate before the gas-permeable non-porous layer 212 is laminated and the gas permeation after the gas-permeable membrane is laminated. D (g / m ² ), which is the difference between the basis weight F (g / m ² ) of the non-porous layer 212 and the base material, is determined by the following relational expression (1).

  D = FE (Equation 1)

  The basis weight of the gas-permeable non-porous layer 212 and the substrate is a value measured by mass per unit area in JIS 1913: 2010 General Nonwoven Fabric Test Method 6.2.

  The thickness of the gas-permeable non-porous layer 212 is preferably 10 μm or more and 500 μm or less, and more preferably 20 μm or more and 200 μm or less. The thickness of the gas-permeable non-porous layer 212 is a value measured by JIS 1913: 2010 General Nonwoven Fabric Test Method 6.1 Thickness Measurement Method.

(Microbial support layer 213)
The microorganism support layer 213 is a layer that holds microorganisms on the surface or inside thereof, has a space in which microorganisms can grow, and allows organic substances in water to pass through. Examples of the material of the microorganism support layer 213 include a porous sheet such as a mesh, a woven fabric, a nonwoven fabric, a foam, or a microporous membrane. The material of the porous sheet is 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, polyimide, polyphenylene sulfide, para- and meta-aramid, polyarylate, carbon fiber, glass fiber, aluminum fiber, steel fiber, ceramic and the like can be mentioned. In consideration of microbial adhesion and processability, polyolefin resins, polyester resins, polyamide resins, acrylic resins, polyurethane resins, and carbon fibers are preferred.

Basis weight of the microbial support layer 213 is 2 g / m ² or more, preferably 500 g / m ² or less, more preferably 10 g / m ² or more 200 g / m ² or less. The basis weight of the microorganism supporting layer 213 is a value measured by mass per unit area in JIS 1913: 2010 General Nonwoven Fabric Test Method 6.2.

  The thickness of the microorganism support layer 213 is preferably 5 μm or more and 2000 μm or less, and more preferably 20 μm or more and 500 μm or less. The thickness of the microorganism supporting layer 213 is a value measured by JIS 1913: 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 substrate 211. By doing so, the surface treatment can increase the roughness and the membrane potential of the surface of the substrate 211, so that the microbial adhesion is improved. For example, as the above surface treatment, glycidyl methacrylate may be graft-polymerized, and further reacted with diethylamine or sodium sulfite. Alternatively, as the above surface treatment, ammonia or ethylamine may be reacted after graft polymerization of glycidyl methacrylate.

(Blower 41)
The blower 41 supplies oxygen to wastewater containing organic matter through the gas permeable membrane 21 by blowing air into a space above the opening 21 b of the gas permeable membrane 21. Thereby, oxygen can be supplied to the wastewater without using an aeration device. Since air is blown without using a pipe that generates a pressure loss, it is not necessary to use a configuration (that is, a compressor) for compressing and sending gas such as a compressor or a blower. For this reason, it becomes possible to operate the wastewater treatment device with more energy saving as compared with the case where a blower is used. In the illustrated embodiment, one blower 41 blows air into a space above the openings 21 b of the plurality of gas permeable films 21. Thereby, even if the scale of the wastewater treatment apparatus is increased and the number of gas permeable membranes 21 provided in the apparatus is increased, it is possible to efficiently supply air to many gas permeable membranes 21.

  It is desirable that the blower 41 be installed in a space above the gas permeable membrane 21. Preferably, the upper space of the gas permeable membrane 21 is such that, in the vertical direction, the center position of the blower 41 is located above the uppermost part of the gas permeable membrane 21, and in the horizontal direction, the center position of the blower 41 is Is a space located within a radius of 5 m, more preferably within 3 m from at least a part of the space. When the blower 41 is installed in such an upper space of the gas permeable membrane 21, the supply amount of air to the gas permeable membrane 21 increases, and oxygen can be sufficiently supplied to wastewater containing organic matter.

  Alternatively, the blower 41 may be installed at a position away from the gas permeable membrane 21. In this case, the blower 41 blows air into the space above the opening 21b of the gas permeable membrane 21 through a pipe having a low pressure loss, for example, without substantially considering the pressure loss. Here, the pipe having a low pressure loss is, for example, a pipe having a pressure loss of about 2 kPa or less, and preferably a pipe having a pressure loss of about 1 kPa or less.

  Note that the blower and the blower are separately defined in JIS B0132. According to JIS B0132, a blower is a machine that gives energy to gas by the rotational movement of an impeller, and has an energy per unit mass of less than 25 kNm / kg. The blower is a compressor having an effective discharge pressure of 200 kPa or less.

In the present invention, since the bag-shaped gas-permeable membrane 21 is used, the structure is easy to supply air. Therefore, even if a blower is used, the structure is such that oxygen is sufficiently distributed throughout the film. Therefore, the blower can perform efficient wastewater treatment with lower power than the compressor. For example, a small blower EP-80EL (manufactured by Yasunaga, rated pressure 14.7 KPa, air volume 80 L / min) used in a combined septic tank consumes 56/59 W (50/60 Hz) of electric power, whereas a pump-type toilet. The blower SP-30 used (made by Nippon Denko, air volume 48 m ³ / h = 600 L / min) consumes 16/15 W (50/60 Hz), and can be operated with about 30% of the power consumption of the blower. Become.

(Lid 43)
A cover 43 (or a cover 43) can be provided in the upper space of the gas permeable membrane 21 in order to more reliably send air to the gas permeable membrane 21 by blowing air from the blower 41. By installing the lid 43, the air sent by the blower 41 is guided to the gas passage S in the gas passage layer 12 without being diffused, and is sent to the gas permeable membrane 21.

  The lid 43 is desirably provided so as to seal the upper space of the wastewater treatment tank 51 as much as possible. Here, the air flow F can be provided in the wastewater treatment device 50 by appropriately setting the air inlet and the air outlet.

  For example, if the blower 41 is installed on a part of the lid 43, for example, on the side wall of the lid 43, the blower 41 can be used as an air intake. Further, if a louver 44 is provided on a part of the lid 43, for example, on a side wall of the lid 43, the louver 44 can be used as an air outlet. The louver 44 can prevent the inflow of rain and the inflow of flying objects such as fallen leaves into the wastewater treatment tank 51.

  When the blower 41 and the louver 44 are installed on the side wall of the lid 43, it is preferable that the side wall on which the blower 41 is installed and the side wall on which the louver 44 is installed are located at opposite positions as shown in FIG.

  In addition, by operating the blower 41 with the blades rotating in the reverse direction, the air flow F is in the opposite direction to the direction of the arrow shown in the figure. As a result, the louver 44 serves as an air inlet, and the blower 41 serves as an air outlet.

  The lid 43 can be formed using various materials such as wood, resin, metal, and concrete. For example, the lid 43 may be made of a transparent resin, and the wastewater treatment tank 51 may receive sunlight. The lid 43 may be formed in a roof (or roof) shape that covers the inside 51 of the wastewater treatment tank.

(Partition 45)
The partition 45 can be installed in the upper space of the gas permeable membrane 21 in order to more reliably send air to the gas permeable membrane 21 by blowing air from the blower 41. Preferably, the partition 45 extends in the vertical direction. Preferably, the partition 45 is provided on the ceiling of the lid 43.

  The partition 45 divides the space above the opening 21b of the gas permeable membrane 21 into a first space 46A and a second space 46B. The first space 46 </ b> A is directly blown by the blower 41. The second space 46B is supplied with air through the first space 46A and the bag-shaped space 21a in the gas permeable membrane 21. The gas flow path S in the gas passage layer 12 becomes a gas flow path in the depth direction of the water, and a bag-shaped space 21 a in the gas permeable film 21 between the gas passage layer 12 and the gas permeable film 21 is formed in a horizontal direction. It becomes a gas flow path.

  The horizontal gas flow path can be provided in various ways. For example, as shown in FIG. 3, as the gas passage layer 12 (for example, the core material 12 a), a plastic corrugated cardboard having a hole in its surface is formed in a bag-like space 21 a of the gas permeable membrane 21 so that its ridge extends in the horizontal direction. , A horizontal gas flow path can be provided. Alternatively, in FIG. 7, holes (not shown) may be provided in the core material 12a so that gas is supplied between adjacent gas channels S extending in the water depth direction.

  In the gas passage layer 12, gas flow paths in the water depth direction and the horizontal direction are provided. Thus, in one gas permeable film 21, an air flow F is formed from the opening 21b located on the first space 46A side to the opening 21b located on the second space 46B side. This flow F of air is an open flow path leading from the first space 46A to the second space 46B.

  By installing the partition 45 in this manner, the blower 41 can be moved from the first space 46A to the second space 46A through the gas flow channels in the water depth direction and the horizontal direction provided in the gas passage layer 12 of the gas supply body 10. The air is supplied to the space 46B. When the blades of the blower 41 are operated in reverse rotation, the air flow F is in the opposite direction to the direction of the arrow shown in the figure. In this case, the blower 41 supplies air from the second space 46B to the first space 46A through gas channels in the water depth direction and the horizontal direction provided in the gas passage layer 12 of the gas supply body 10.

  The partition 45 can be installed, for example, by suspending it on the ceiling of the lid 43. Alternatively, the partition 45 may be integrated with the lid 43 and configured as a part of the ceiling of the lid 43. When the partition 45 is provided, it is preferable to provide an air inlet or outlet in each of the first space 46A and the second space 46B in order to form the air flow F.

  In the illustrated embodiment, the partition 45 is provided on the ceiling portion of the lid 43, but the partition 45 is installed, for example, at the upper end of the opposite side wall of the wastewater treatment tank 51 so that both ends of the partition 45 are bridged. May be. Thereby, the wastewater treatment apparatus 50 can be configured to include the partition 45 without the lid 43.

  The partition 45 can be formed using various materials such as wood, resin, metal, and concrete. When the partition 45 is formed integrally with the lid 43, the partition 45 can be formed using the same material as the lid 43.

  As described above, according to the wastewater treatment apparatus 50 of the present invention, the aerobic treatment can be performed using the gas permeable membrane 21 without aeration. The air supply to the gas permeable membrane 21 by the blower 41 is different from a mode in which air is compressed and blown by a compressor, a blower, or the like, and the power cost can be reduced. Thereby, energy saving performance can be improved.

  The blower 41 blows air into the space above the opening 21b of the gas permeable membrane 21 without using a pipe that causes a pressure loss. Therefore, it is not necessary to use a configuration such as a compressor or a blower for compressing and sending gas, and it is possible to operate the wastewater treatment apparatus with more energy saving as compared with the case where a blower is used. Since the gas is reliably sent to the gas permeable membrane 21 by the blower 41, the gas containing oxygen is sufficiently supplied to the biological membrane, and the treatment efficiency of the wastewater is also improved.

Further, by providing the lid 43 or the partition 45, it is possible to more reliably supply the gas to the gas permeable membrane 21, and the treatment efficiency of the wastewater is improved.
[Other forms]

  As described above, the present invention has been described with reference to the specific embodiments. However, the present invention is not limited to the above embodiments.

  For example, in the above-described embodiment, an example in which the planar gas supply body 10 is used has been described. However, the present invention is not limited to this. For example, the gas supply body 10 may be wound, or a gas supply body molded into a cylindrical shape may be used.

  In the above embodiment, the inflow port 51a is provided above the wastewater treatment tank 51, and the wastewater W is supplied from above the wastewater treatment tank 51, but the present invention is not limited to this. For example, the inflow port 51a may be provided at the lower part of the wastewater treatment tank 51, and the wastewater W may be supplied from the lower part of the wastewater treatment tank 51.

DESCRIPTION OF SYMBOLS 10 Gas supply body 12 Gas passage layer 12a Core material 12b Front liner 12c Back liner 13 Gas passage hole 21 Gas permeable film 21a Inside bag 21b Opening 21c Edge 41 of the periphery of bag Blower (fan)
43 lid 44 louver 45 partition 46A space (first space)
46B space (second space)
Reference Signs List 50 wastewater treatment apparatus 51 wastewater treatment tank 51a inflow port 51b outflow port 53 baffle plate 211 base material 212 gas-permeable nonporous layer 213 microorganism support layer S gas flow path T treated water W wastewater

Claims (8)

A wastewater treatment device for treating organic substances by the action of aerobic microorganisms contained in wastewater stored in a wastewater treatment tank,
A bag-shaped gas permeable membrane, which is provided in the wastewater treatment tank and has a surface for taking in gas containing oxygen in the atmosphere from an opening protruding from the surface of the wastewater, and having a surface on which the aerobic microorganisms proliferate,
A blower that blows air into a space above the opening of the gas permeable membrane,
A wastewater treatment device comprising:   The wastewater treatment apparatus according to claim 1, further comprising a lid that covers the space above the opening.   The wastewater treatment apparatus according to claim 1, further comprising a partition that divides the space above the opening. The partition, a space above the opening of the gas permeable membrane,
A first space directly blown by the blower,
A second space that is supplied with air through the first space and a bag-shaped space in the gas permeable membrane;
The wastewater treatment device according to claim 3, wherein the wastewater treatment device is divided into:   The wastewater treatment device according to any one of claims 1 to 4, wherein the bag-shaped gas permeable membrane has the opening at one end and the other end is closed. A gas supply comprising the gas permeable membrane and a gas passage layer, further provided in the wastewater treatment tank,
The wastewater treatment apparatus according to any one of claims 1 to 5, wherein the gas containing oxygen that has passed from the gas permeable layer to the gas permeable membrane passes through the gas permeable membrane and is supplied to the wastewater. .   The wastewater treatment apparatus according to claim 6, wherein a gas flow path in a depth direction and a gas flow path in a horizontal direction are provided inside the gas supply body.   The wastewater treatment apparatus according to any one of claims 1 to 7, wherein one blower blows air into the space above the openings of the plurality of gas permeable membranes.