JP2008237997A - Waste water treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waste water treatment apparatus capable of promoting the production of aerobic granules. <P>SOLUTION: The waste water treatment apparatus 1A utilizing aerobic granules Gr is equipped with: an activated sludge tank 3 into which organic waste water W is introduced, and forming the aerobic granules Gr; and a peeling device 9 peeling a biofilm stuck to the inner wall face 3c of the activated sludge tank 3. In the waste water treatment apparatus 1A, a biofilm stuck to the inner wall face 3c of the activated sludge tank 3 and grown can be peeled. Aerobic microorganisms in the activated sludge tank 3 form the aerobic granules Gr with the peeled biofilm as a nucleus. As a result, the production of the aerobic granules Gr can be promoted. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wastewater treatment apparatus for biologically treating organic wastewater using aerobic granules.

A method for producing aerobic granules under aerobic conditions using a batch activated sludge method or the like is known. Since the aerobic granule has a high density of aerobic microorganisms and can be subjected to a high load treatment, a wastewater treatment method using the aerobic granule has attracted attention. Patent Documents 1 to 3 disclose an apparatus for performing wastewater treatment using aerobic granules.
International Publication No. 98/37027 Pamphlet JP 2005-517532 A JP 2005-538825 A

  However, it is difficult to produce aerobic granules as compared to generally well-known anaerobic granules, and it has been difficult to efficiently and sufficiently produce aerobic granules with conventional devices.

  The object of the present invention is to solve the above problems, and to provide a wastewater treatment apparatus that can promote the generation of aerobic granules.

  The inventor of the present invention diligently studied to achieve the above object, and as a result, when the biofilm attached to the inner wall surface of the treatment tank is peeled off from the wall surface, the biofilm itself becomes a nucleus and an adhesive element (hereinafter simply “nucleus”). It was found that aerobic granules were produced. In particular, in a treatment tank that flows at a constant flow rate, even if a biofilm is generated by floating microorganisms, the biofilm is easily flowed and dispersed, and is unlikely to become the nucleus of an aerobic granule. However, in the vicinity of the inner wall surface of the treatment tank, the flow velocity is lower than that at the center, so that the biofilm is likely to collect and adhere to the inner wall surface and grow easily. A grown biofilm is effective as a nucleus for aerobic granules. The present invention has been made based on the above findings.

  The present invention relates to a wastewater treatment apparatus using aerobic granules, in which organic wastewater is introduced, and a treatment tank for generating aerobic granules and a peeling means for peeling a biofilm attached to the inner wall surface of the treatment tank. And.

  In this wastewater treatment apparatus, the biofilm that has grown on the inner wall surface of the treatment tank can be peeled off. The aerobic microorganism in the treatment tank forms an aerobic granule using the peeled biofilm as a nucleus. As a result, the generation of aerobic granules is promoted.

  Furthermore, it is preferable that the organic wastewater flows in the treatment tank, and the peeling means accelerates the flow rate of the organic wastewater in the vicinity of the inner wall surface of the treatment tank. Since the biofilm can be peeled from the inner wall surface using the flow of the organic wastewater flowing in the treatment tank, the efficiency is good. Therefore, the generation of aerobic granules can be effectively promoted.

  Furthermore, the treatment tank is cylindrical, and the peeling means extends so as to intersect the axis of the treatment tank to regulate the flow of organic wastewater, and is arranged with a gap between the inner wall surface of the treatment tank. It is preferable to have a board portion that is made. The gap between the board portion and the inner wall surface acts as a nozzle because the flow path is narrowed. As a result, it is possible to reliably increase the flow velocity in the vicinity of the inner wall surface, and promote the peeling of the biofilm from the inner wall surface, thereby effectively promoting the generation of aerobic granules.

  Further, it is preferable that an opening through which the organic waste water passes is formed in the board part. By forming an opening in the board part, pressure loss of flowing organic waste water can be reduced, and appropriate flow is enabled.

  Further, it is preferable that the board part is provided with a flow rate adjusting part for adjusting the flow rate of the organic waste water passing through the opening. When the flow rate at the opening is reduced, the flow rate of the organic wastewater passing through the gap between the board portion and the inner wall surface becomes faster, and when the restriction at the opening is loosened, the flow rate of the organic wastewater passing through the gap becomes slower. Therefore, by adjusting the flow rate of the organic wastewater that passes through the opening, the flow rate of the organic wastewater that passes through the gap can be adjusted, and the biofilm can be efficiently peeled off.

  Further, it is preferable that the peeling means further includes a drive unit that moves the board part along the inner wall surface. With this configuration, the biofilm can be uniformly peeled from the inner wall surface.

  Moreover, it is suitable that the peeling means of the wastewater treatment apparatus according to the present invention has a brush portion that is disposed in the treatment tank and moves along the inner wall surface. The brush part peels off the biofilm attached to the inner wall surface when moving along the inner wall surface. As a result, the biofilm can be reliably peeled from the inner wall surface.

  Further, the treatment tank of the wastewater treatment apparatus according to the present invention has a cylindrical shape having an axis along the flow of the organic wastewater, and the peeling means rotates along with the rotation shaft portion disposed in the treatment tank. A bearing portion that rotatably supports the shaft portion, a circular movable portion that is fixed to the rotation shaft portion, a rotary blade that is provided on the circumferential surface facing the inner wall surface of the movable portion, and that is in sliding contact with the inner wall surface; It is preferable to have The rotating blade receives force from the organic wastewater flowing in the treatment tank, and the movable part rotates. The rotating blade that rotates together with the movable part agitates the vicinity of the inner wall surface of the treatment tank and can efficiently peel the biofilm.

  Furthermore, it is preferable to further include a drive unit that moves the rotary shaft along the axis. When the rotary shaft moves along the axis, the flow rate of the organic wastewater that passes through the rotor blades is relatively increased even if the flow rate of the organic wastewater flowing in the treatment tank is constant, and the movable part rotates faster. Become. As a result, the biofilm can be effectively peeled off.

  According to the waste water treatment apparatus according to the present invention, the generation of aerobic granules can be promoted.

  Hereinafter, preferred embodiments of a wastewater treatment apparatus according to the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a cross-sectional view showing an outline of a wastewater treatment apparatus according to the present invention. The wastewater treatment apparatus 1A is an apparatus that decomposes organic matter using granular (also referred to as “granular”) sludge (aerobic granules).

  The wastewater treatment apparatus 1A produces an aerobic granule Gr and holds the activated sludge tank (treatment tank) 3 and a part of the supernatant water from the upper part of the activated sludge tank 3, and the lower part of the activated sludge tank 3 And an aeration apparatus 7 for supplying air or a gas having a higher oxygen concentration than air from the bottom of the activated sludge tank 3.

  The activated sludge tank 3 has a substantially cylindrical shape, and at the top of the activated sludge tank 3, a discharge part 3a for discharging a part of the supernatant water as treated water Ws and another part of the supernatant water are supplied to the circulation tank 5. And a circulating portion 3b. The circulation tank 5 is provided with an introduction part 5 a for the organic waste water W, and the supernatant water supplied from the activated sludge tank 3 is mixed in the circulation tank 5. Further, the circulation tank 5 is provided with a return portion 5b for supplying the organic waste water W mixed with the supernatant water to the lower part of the activated sludge tank 3, and the organic fed from the circulation tank 5 into the activated sludge tank 3 is provided. The waste water W flows as an upward flow along the axis L of the activated sludge tank 3.

  In the activated sludge tank 3, a peeling device (peeling means) 9 for peeling the biofilm B attached to the inner wall surface 3c is attached. The peeling apparatus 9 includes a shaft portion 11 that extends along the axis L of the activated sludge tank 3. The shaft portion 11 passes through the ceiling portion 3f and the bottom portion 3g of the activated sludge tank 3 in a sealed state, and is lifted and lowered by an upper bearing portion 13 provided on the ceiling portion 3f and a lower bearing portion 15 provided on the bottom portion 3g. It is supported freely. Further, the upper end of the shaft portion 11 is fixed to the movable arm 17 of the driving portion 16. The drive unit 16 is an elevator including an electric motor, a hydraulic motor, and the like, and moves up and down the shaft unit 11 along the axis L by moving the movable arm 17.

  A disc-shaped diverter (board part) 19 is fixed to the shaft part 11. The distribution plug 19 is disposed on the horizontal plane orthogonal to the axis L in the activated sludge tank 3. Further, the diameter of the diversion plug 19 is slightly smaller than the inner diameter of the activated sludge tank 3, and the diversion plug 19 is provided with a slight gap, that is, a narrow region S between the inner wall surface 3 c of the activated sludge tank 3. Has been placed. Further, the diverter 19 is provided with a diverter pipe (opening) 21 penetrating the diverter 19 along the axis L, and the diverter pipe 21 is a control valve for adjusting the flow rate by adjusting the opening degree. A (flow rate adjusting unit) 23 is provided. A peeling device 9 is configured by the shaft portion 11, the diversion plug 19, and the driving portion 16.

  Next, continuous activated sludge treatment using the wastewater treatment apparatus 1A will be described. This activated sludge treatment is a wastewater treatment method in which an environment in which aerobic granules Gr are generated is prepared and organic substances are decomposed and removed efficiently using the aerobic granules Gr.

  Aerobic microorganisms that decompose organic matter as a substrate (nutrient) produce a highly viscous biofilm (also called “extracellular polymer” or “PES”) B in the process, Aerobic microorganisms gather to form activated sludge. Furthermore, when activated sludge has a core substance, it adheres around the substance to form agglomerated agglomerated activated sludge, and the agglomerated activated sludge grows (grows) and granulates. Thus, a larger granular activated sludge, that is, an aerobic granule Gr is formed. Since the aerobic granule Gr has a high density of aerobic microorganisms, if the amount of the aerobic granule Gr is increased, the ability to decompose organic substances per unit volume in the activated sludge tank 3 is improved, and the load is high. It becomes possible to deal with organic wastewater W.

  The floating biofilm B acts as a nucleus when the aerobic granule Gr is formed. However, in the activated sludge tank 3 in which the organic waste water W is flowing upward, the biofilm B is easy to disperse and hardly acts as the core of the aerobic granule Gr.

  However, in the vicinity of the inner wall surface 3c of the activated sludge tank 3, conversely, the flow rate becomes slow and the biofilm B tends to gather, and the concentration of the biofilm B in the vicinity of the inner wall surface 3c increases and adheres to the inner wall surface 3c. It becomes easy to do and growth is encouraged. The grown biofilm acts as a nucleus of the aerobic granule Gr when peeled from the inner wall surface 3c. Therefore, the production of aerobic granules Gr can be promoted by making more nuclei. In the present wastewater treatment method, in order to effectively use the above phenomenon, an attachment step for attaching the biofilm B to the inner wall surface and growing, and an aerobic granulation by peeling the grown biofilm B from the inner wall surface 3c. The peeling step to make the core of Le Gr is repeated alternately.

(Adhesion step)
In the wastewater treatment apparatus 1 </ b> A, the organic wastewater W is continuously supplied via the circulation tank 5. A part of the supernatant water drawn from the activated sludge tank 3 is supplied into the circulation tank 5, and the organic waste water W merged with the supernatant water is supplied to the activated sludge tank 3. In the activated sludge tank 3, the organic waste water W flows as an upward flow, and a part of the supernatant water of the organic waste water W is supplied to the circulation tank 5. By this circulation, the aerobic microorganisms in the activated sludge are decomposed with the organic matter in the organic wastewater W as a substrate (nutrient), and the biofilm B is generated.

  Until the biofilm B grows on the inner wall surface 3c, the diverter 19 is kept at a predetermined position, for example, the upper position P1 of the activated sludge tank 3. Further, the control valve 23 is opened to hold the diverter pipe 21 in a fully opened state, and the flow of the narrow region S between the diverter plug 19 and the inner wall surface 3c is kept as low as possible. As a result, the biofilm B easily collects in the vicinity of the inner wall surface 3c having a low flow velocity, and grows mainly at a position below the inner wall surface 3c with the passage of time.

(Peeling step)
When the biofilm B grows on the inner wall surface 3 c, the opening degree of the branch pipe 21 is reduced by the control valve 23. Then, the flow rate of the organic waste water W passing through the narrow region S between the diversion plug 19 and the inner wall surface 3c is increased, and the narrow region S acts as a nozzle to peel the biofilm B attached to the inner wall surface 3c. . Furthermore, the drive part 16 is driven, the axial part 11 is moved, and the diverter 19 is moved from the upper position P1 to the lower position P2 together with the axial part 11. As a result, the narrow region S descends along the inner wall surface 3c, and the biofilm B can be peeled evenly over almost the entire inner wall surface 3c.

  The biofilm B peeled off from the inner wall surface 3c becomes the nucleus of the aerobic granule Gr. Activated sludge containing aerobic microorganisms adheres to the core and forms agglomerated activated sludge. Also in the agglomerated activated sludge, the biofilm B is generated, and the agglomerated activated sludge is propagated (growth) and granulated by the proliferation to form the aerobic granules Gr. As a result, the generation of the aerobic granules Gr can be promoted, and the decomposition treatment of the organic waste water W is promoted.

  In the wastewater treatment apparatus 1A according to the first embodiment, the biofilm B is peeled off by effectively using the flow of the flowing organic wastewater W by increasing the flow rate of the organic wastewater W in the vicinity of the inner wall surface 3c. . In particular, in order to form a narrow region S that acts as a nozzle between the diversion plug 19 and the inner wall surface 3c, the flow velocity in the vicinity of the inner wall surface 3c is reliably increased, and the biofilm B is peeled off from the inner wall surface 3c. This can promote the production of aerobic granules Gr effectively.

  Furthermore, since the diversion pipe 19 is provided with the diversion pipe 21 through which the organic waste water W passes, the pressure loss of the flowing organic waste water W can be reduced, and appropriate flow is enabled. In particular, since the control pipe 23 for adjusting the flow rate of the organic waste water W is provided in the shunt pipe 21, the flow speed in the narrow region S is increased by narrowing the shunt pipe 21. By loosening, the flow velocity in the narrow region S can be slowed, and the biofilm B can be peeled off efficiently.

  In this embodiment, the diverter plug 19 is not in contact with the inner wall surface 3c. However, a part of the diverter plug 19 may be in contact with the inner wall surface 3c.

(Second Embodiment)
Next, a wastewater treatment apparatus 1B according to the second embodiment will be described with reference to FIGS. The waste water treatment apparatus 1B is mainly different from the waste water treatment apparatus 1A according to the first embodiment in a peeling device (peeling means) 25. Therefore, it demonstrates centering on the peeling apparatus 25, about the structure similar to 1A of waste water treatment apparatuses, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The peeling device 25 includes a rotating shaft portion 26 that extends along the axis L of the activated sludge tank 3. The rotating shaft portion 26 passes through the ceiling portion 3f and the bottom portion 3g of the activated sludge tank 3 in a sealed state, and is constituted by an upper bearing portion 13 provided on the ceiling portion 3f and a lower bearing portion 15 provided on the bottom portion 3g. It is supported so that it can move up and down and rotate freely. Furthermore, the upper end of the rotating shaft part 26 is rotatably attached to the movable arm 29 of the driving part 27. The drive unit 27 is an elevator equipped with an electric motor, a hydraulic motor, or the like, and moves the movable arm 29 up and down along the axis L. Furthermore, the drive part 27 is provided with the electric motor which rotates the rotating shaft part 26 via a chain sprocket mechanism etc.

  A disc-shaped diverter (movable part) 31 is fixed to the rotating shaft part 26. The diversion plug 31 is disposed on the horizontal plane orthogonal to the axis L in the activated sludge tank 3. The diameter of the diverter 31 is smaller than the inner diameter of the activated sludge tank 3, and a brush portion 37 is provided on the peripheral surface 31 a of the diverter 31 facing the inner wall surface 3 c. The brush portion 37 is a bundle of animal hairs or artificial fibers, fixed, a large number of linear needles made of resin or metal such as plastic, and a large number of U-shaped curved needles. It is formed using things etc., and is elastically deformed in contact with the inner wall surface 3c. Further, the diverter 31 is provided with a diverter pipe (opening) 39 that passes through the diverter 31 along the axis L, and the diverter pipe 39 has an adjustment valve (flow rate) for adjusting the flow rate by adjusting the opening degree. An adjustment unit) 40 is provided. The peeling device 25 is configured by the rotating shaft portion 26, the diverter 31, the brush portion 37, and the driving portion 27.

  When the rotary shaft portion 26 is rotated while being driven by the drive portion 27, the brush portion 37 is rotated together with the diverter 31, and the inner wall surface 3 c is slid in the vertical direction. The elastically deformed brush part 37 peels off the biofilm B adhering to the inner wall surface 3c so as to be scraped out while moving, and effectively peels off the biofilm B. In addition, in 2nd Embodiment, although the brush part 37 was provided over the perimeter of the surrounding surface 31a of the diverter 31, you may make it provide in a part of surrounding surface 31a.

(Third embodiment)
Next, a wastewater treatment apparatus according to the third embodiment will be described with reference to FIG. In addition, the structure of the diverter (movable part) 42 differs in the wastewater treatment apparatus which concerns on 3rd Embodiment compared with the wastewater treatment apparatus 1B which concerns on 2nd Embodiment. Therefore, it demonstrates centering on the diverter 42, about the structure similar to 1 A of wastewater treatment apparatuses, attaches | subjects the same code | symbol and abbreviate | omits description.

  The diversion plug 42 includes a circular frame portion 42a and a net-like screen portion 42b provided inside the frame portion 42a. In the diverter 42, the center of the screen portion 42 b is fixed to the rotary shaft portion 26, and the diverter 42 is disposed on a horizontal plane perpendicular to the axis L. Furthermore, the brush part 43 is provided in the surrounding surface 42c of the frame part 42a facing the inner wall surface 3c. The brush portion 43 has the same configuration as the brush portion 37 according to the second embodiment, and is elastically deformed in contact with the inner wall surface 3c.

(Fourth embodiment)
Next, a wastewater treatment apparatus 1D according to the fourth embodiment will be described with reference to FIGS. The wastewater treatment apparatus 1D is mainly different from the wastewater treatment apparatus 1B according to the second embodiment in a peeling device (peeling means) 45. Therefore, it demonstrates centering on the peeling apparatus 45, about the structure similar to the waste water treatment apparatus 1B, attaches | subjects the same code | symbol and abbreviate | omits description.

  The peeling device 45 includes a rotating shaft portion 47 that extends along the axis L of the activated sludge tank 3. The rotating shaft portion 47 passes through the ceiling portion 3f and the bottom portion 3g of the activated sludge tank 3 in a sealed state, and is constituted by an upper bearing portion 13 provided on the ceiling portion 3f and a lower bearing portion 15 provided on the bottom portion 3g. It is supported so that it can move up and down and rotate freely. Furthermore, the upper end of the rotating shaft portion 47 is rotatably attached to the movable arm 51 of the driving portion 49. The drive unit 49 is an elevator equipped with an electric motor or a hydraulic motor, and moves the movable arm 29 up and down along the axis L. In addition, the drive part 49 is not provided with the electric motor for rotating the rotating shaft part 47 unlike the drive part 27 which concerns on 2nd Embodiment.

  A disc-shaped diverter (movable part) 53 is fixed to the rotating shaft 47. The diversion plug 53 is disposed on a horizontal plane perpendicular to the axis L in the activated sludge tank 3. The diameter of the diversion plug 19 is smaller than the inner diameter of the activated sludge tank 3, and a rotary blade 55 is provided on the peripheral surface 53 a facing the inner wall surface 3 c of the diversion plug 53 with a predetermined clearance from the inner wall surface 3 c. It has been. The rotary blade 55 is formed using rubber, plastic, metal, or the like. Further, the diverter 53 is provided with a diverter pipe 57 penetrating the diverter 53 along the axis L, and the diverter pipe 57 is provided with a control valve (flow rate adjustment) for adjusting the opening and adjusting the flow rate. Part) 59 is provided. A peeling device 45 is configured by the rotary shaft portion 47, the diversion plug 53, the rotary blade 55 and the drive portion 49.

  The diversion plug 53 rotates by receiving the upward flow of the organic waste water W by the rotary blade 55. The rotary blade 55 stirs the vicinity of the inner wall surface 3c and efficiently peels the biofilm B adhering to the inner wall surface 3c. Furthermore, when the rotary shaft portion 47 is moved up and down by the drive unit 49, the flow rate of the organic waste water W passing through the rotary blade 55 is substantially increased, and the rotation of the rotary blade 55 is also accelerated, thereby effectively peeling the biofilm B. it can.

  The present invention is not limited to the above embodiment. For example, the wastewater treatment plant according to the present invention is incorporated into a wastewater treatment plant equipped with a large activated sludge tank, and aerobic granules generated by the wastewater treatment apparatus according to the present invention are introduced into the large activated sludge tank. May be.

  Further, the peeling means is not limited to each of the above embodiments, and the biofilm is peeled off by spraying a high-speed fluid on the inner wall surface of the treatment tank, or the biofilm is peeled off by vibrating the inner wall surface. It may be.

It is sectional drawing which shows the outline of the wastewater treatment apparatus which concerns on 1st Embodiment of this invention. It is sectional drawing along the II-II line of FIG. It is sectional drawing which shows the outline of the waste water treatment apparatus which concerns on 2nd Embodiment. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3. It is sectional drawing along the VV line of FIG. It is sectional drawing of the diversion tap which concerns on 3rd Embodiment. It is sectional drawing which shows the outline of the wastewater treatment apparatus which concerns on 4th Embodiment. It is sectional drawing along the VIII-VIII line of FIG. It is a perspective view of a diversion tap concerning a 4th embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1A, 1B, 1D ... Waste water treatment apparatus, 3 ... Activated sludge tank, 3c ... Inner wall surface, 9, 25, 45 ... Peeling device (peeling means), 11 ... Shaft part, 13 ... Upper bearing part, 15 ... Lower bearing part , 26, 47 ... rotating shaft part, 16, 27, 49 ... driving part, 19 ... diversion plug (board part), 21, 39, 57 ... diversion pipe (opening), 23, 40, 59 ... control valve (flow rate adjustment) Part), 31, 42, 53 ... branch plug (movable part), 31a, 42c ... peripheral surface, 37, 43 ... brush part, L ... axis, H ... hole (opening), W ... organic waste water, Gr ... aerobic Granule, B ... Biofilm.

Claims (9)

In wastewater treatment equipment using aerobic granules,
With the introduction of organic wastewater, a treatment tank for producing the aerobic granules,
Peeling means for peeling the biofilm attached to the inner wall surface of the treatment tank;
A wastewater treatment apparatus characterized by comprising: In the treatment tank, the organic wastewater flows,
The waste water treatment apparatus according to claim 1, wherein the peeling means increases a flow rate of the organic waste water in the vicinity of the inner wall surface. The treatment tank is cylindrical,
The peeling means is disposed so as to intersect with the axis of the treatment tank to regulate the flow of the organic waste water, and has a board portion disposed with a gap between the inner wall surface and the peeling means. The wastewater treatment apparatus according to claim 2.   The waste water treatment apparatus according to claim 3, wherein an opening through which the organic waste water passes is formed in the board portion.   The wastewater treatment apparatus according to claim 4, wherein a flow rate adjusting unit that adjusts the flow rate of the organic wastewater that passes through the opening is provided in the panel portion.   The waste water treatment apparatus according to any one of claims 3 to 5, wherein the peeling unit further includes a drive unit that moves the panel unit along the inner wall surface.   The waste water treatment apparatus according to claim 1, wherein the peeling unit includes a brush portion that is disposed in the treatment tank and moves along the inner wall surface. The treatment tank is cylindrical with an axis along the flow of the organic waste water,
The peeling means includes
A rotating shaft portion disposed in the processing tank along the axis, and
A bearing portion that rotatably supports the rotating shaft portion;
A circular movable part fixed to the rotating shaft part;
A rotor blade provided on a peripheral surface facing the inner wall surface of the movable part;
The wastewater treatment apparatus according to claim 1, comprising:   The wastewater treatment apparatus according to claim 8, further comprising a drive unit that moves the rotating shaft along the axis.

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