JP2006051490A - Anaerobic treatment apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anaerobic treatment apparatus which easily reduces the profile of /miniaturizes the apparatus, and an anaerobic treatment method. <P>SOLUTION: The anaerobic treatment apparatus 1 has a side wall 11 partitioning a space containing anaerobic sludge S, and includes an upward flow part R1 for passing waste wate W through the anaerobic sludge S to flow upward, a waste water introduction part 5 for introducing the waste wate W into the upward flow part R1, a solid-liquid separation part 23 for separating solid matters S and SS from the treated water treated in the upward flow part R1 to overflow the upper end of the upward flow part R1, and a fluid circulation path R2 for connecting the solid-liquid separation part 23 with the upward flow part R1 to conduct the solid matters S and SS separated in the solid-liquid separation part 23 downward. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an anaerobic processing apparatus and an anaerobic processing method.

As anaerobic treatment equipment that treats wastewater containing organic matter, UASB (Upflow Anaerobic Sludge Blanket) treatment equipment that decomposes organic matter in wastewater using granular anaerobic sludge, An EGSB (Expanded Granular Sludge Bed) processing apparatus is known (see, for example, Patent Document 1). As an example of these apparatuses, FIG. 7 shows an anaerobic treatment apparatus described in FIG. This anaerobic treatment device 701 is a device in which the sludge filling section 703 in the lower part of the tank is filled with granule sludge, the wastewater introduced from the wastewater introduction section 705 is treated with the granular sludge, and discharged from the treated water discharge section 707. It is. The anaerobic treatment device 701 includes an upward flow portion 702 for flowing waste water upward through the granule sludge, and the upper portion of the upward flow portion 702 separates treated water, granule sludge and generated gas. A phase separator 715 is provided. The granular sludge to which gas has adhered at the lower part of the upward flow portion 702 rises due to the upward flow and the gas lift action. The raised granular sludge collides with the gas collision part 709, is separated from the gas by impact, and settles again. The separated gas is collected in the gas collection unit 711 and discharged from the gas discharge pipe 713. On the other hand, the treated water passes between the gas collision unit 709 and the gas collecting unit 711 and is discharged from the treated water discharge unit 707. In this manner, the anaerobic treatment device 701 performs three-phase separation that separates gas, granular sludge, and treated water.
JP-A-11-128979

  In the anaerobic treatment device 701, a three-phase separation unit 715 is provided in the middle of the wastewater going to the uppermost part 702a of the upward flow unit 702, and the rising granular sludge is collided with the gas collision unit 709 for separation. . Part of the granular sludge that has not been separated by the gas collision unit 709 reaches the uppermost part 702a, and is discharged from the treated water discharge unit 707 into the treated water. For this reason, in the anaerobic treatment device 701, if it is intended to ensure the necessary separation performance, it is necessary to sufficiently take the length of the upward flow portion 702 in the vertical direction and reduce the granular sludge reaching the uppermost portion 702a. There is. Therefore, according to the anaerobic treatment apparatus 701, it is difficult to reduce the height of the apparatus. In order to reduce the height of the tank, it is conceivable that the separation tank is provided with a separate three-phase separation device (see, for example, FIGS. 1 and 2 of Patent Document 1), but this separation tank is installed. For this reason, it is difficult to reduce the size of the apparatus.

  Accordingly, an object of the present invention is to provide an anaerobic treatment apparatus and an anaerobic treatment method that solve the above-described problems and facilitate the reduction in the height and size of the apparatus.

  In order to solve the above problems, the anaerobic treatment apparatus of the present invention is an anaerobic treatment apparatus that treats wastewater using anaerobic sludge, and has a side wall that defines a space for containing anaerobic sludge, An upward flow section that performs anaerobic treatment by flowing wastewater upward through anaerobic sludge, a wastewater introduction section that introduces wastewater into the upward flow section, and an upper flow section that is treated by the upward flow section and passes the upper end of the upward flow section A solid-liquid separation unit that separates solids from the treated water that has flowed, a fluid circulation path that connects the solid-liquid separation unit and the upward flow unit, and guides the solids separated by the solid-liquid separation unit downward; It has.

  Since the said anaerobic processing apparatus is integrally provided with the solid-liquid separation part, it is not necessary to provide a separate solid-liquid separation tank, and an installation space can be made small. Moreover, the solid-liquid separation part of the said anaerobic processing apparatus isolate | separates a solid substance from the treated water which overflowed the upper end of the upward flow part. For this reason, even if the solid material reaches the upper end of the upward flow portion, it is separated from the treated water thereafter, so that the separation performance can be ensured regardless of the vertical height of the upward flow portion. Therefore, according to the said anaerobic processing apparatus, the height of the vertical direction of an upward flow part can be suppressed, and the whole apparatus can be made low-profile. In the present invention, the upper end of the upward flow portion refers to the end portion in the vertical direction of the member that partitions the space of the upward flow portion and is the highest position. In addition, the solid matter here refers to suspended solids (Suspended Solids: fine particles of 2 mm or less) contained in the wastewater introduced into the upstream portion, anaerobic sludge for treating the wastewater anaerobically, or the above suspended matter. It refers to any of the mixtures with the anaerobic sludge.

  Moreover, in the said anaerobic processing apparatus, since the fluid circulation path | route is provided, the solid substance isolate | separated by the solid-liquid separation part is returned below by the path | route different from the rising solid substance. Therefore, even if anaerobic sludge is contained in the separated solid matter, anaerobic sludge in the solid matter heading downward and anaerobic sludge in the rising solid matter are not mixed. Moreover, according to the said anaerobic processing apparatus, the solid substance which does not need reuse, such as a suspended solid, can be guided below by a fluid circulation path.

  In the anaerobic treatment apparatus of the present invention, the fluid circulation path may connect the solid-liquid separation part and the lower part of the upward flow part than the waste water introduction part.

  In this anaerobic treatment apparatus, the solid matter separated by the solid-liquid separation unit is returned below the wastewater introduction unit. And the activity of anaerobic sludge is equalize | homogenized by exchanging the anaerobic sludge accommodated in the upward flow part up and down. In addition, the fluid circulation path is a path different from the upward flow section, and connects the solid-liquid separation section and the lower part of the waste water introduction section, so that it is affected by the upward flow in the upward flow section. Thus, a downward flow is generated in the fluid circulation path. Therefore, the solid that settles in the fluid circulation path is smoothly guided downward by gravity and downward flow. Moreover, according to this anaerobic processing apparatus, the solid substance which does not need reuse, such as a suspended substance, can also be guided below by a fluid circulation path.

    Moreover, as for the anaerobic processing apparatus of this invention, a fluid circulation path may connect the upper part rather than the anaerobic sludge bed in which anaerobic sludge settles in the lower part of a solid-liquid separation part and an upward flow part.

  In this anaerobic treatment apparatus, the solid matter returned downward in the fluid circulation path is smoothly returned to the upward flow section above the anaerobic sludge bed without receiving the great resistance of the anaerobic sludge bed. Therefore, it is possible to suppress the solid matter from stagnation in the fluid circulation path. Moreover, according to this anaerobic processing apparatus, the solid substance which does not need reuse, such as a suspended substance, can also be guided below by a fluid circulation path.

  In the anaerobic treatment apparatus of the present invention, the upper end of the upward flow portion includes the upper end of the side wall, and the solid-liquid separation portion is provided on the outer peripheral portion of the upward flow portion so as to surround the upper end of the upward flow portion. It may be characterized by that.

  If it does in this way, the gas adhering to sludge as a bubble will be released | separated from a solid substance in the liquid level of the uppermost center part of an upward flow part. As a result, the solid matter loses buoyancy and settles again, and is returned to the lower part of the upward flow portion. In addition, since the solids that have not settled here and have overflowed the end of the upward flow part are less affected by the buoyancy of the gas and easily settle, the fluid circulation path smoothly settles, Efficient separation from treated water.

  In addition, the anaerobic treatment apparatus of the present invention has a guide plate provided so that the solid-liquid separation unit is separated from the upward flow part and surrounds the upper end of the upward flow part, The solid material that has flowed over the upper end of the upward flow portion may be guided to the fluid circulation path. By providing the guide plate in this way, the solid is efficiently introduced into the fluid circulation path and efficiently guided downward.

  Further, in the anaerobic treatment apparatus of the present invention, the fluid circulation path includes a gap portion sandwiched between the side wall of the upward flow portion and another side wall provided so as to surround the side wall. May be a feature.

  Further, the anaerobic treatment device of the present invention may be characterized in that the fluid circulation path includes a hollow portion of a tubular member extending from the solid-liquid separation part to a position below the waste water introduction part.

  A rectifying plate may be further provided inside the upward flow portion and above the waste water introduction portion to rectify the flow of the waste water in the upward flow portion in the vertical direction. If the current plate is provided in this way, waste water and the like smoothly flow in the upward flow portion.

  In addition, the anaerobic treatment apparatus of the present invention may further include a drawing path for discharging solid matter that settles in the fluid circulation path to the outside of the upward flow portion. Thus, if a drawing path is provided, solids that do not need to be reused can be discharged to the outside of the upward flow part, and these solids are prevented from accumulating in the upward flow part. Can do.

  Further, the anaerobic treatment method of the present invention is an anaerobic treatment method for treating wastewater using anaerobic sludge, and the wastewater is introduced from the wastewater introduction part to the lower part of the upward flow part containing the anaerobic sludge. Then, the introduced wastewater is anaerobically treated while flowing upward in the upward flow part, and the solid-liquid separation part provided at the upper part of the upward flow part is anaerobically treated and overflows the upper end of the upward flow part. The treated water and the anaerobic sludge mixed in the treated water are separated, and the anaerobic sludge separated by the solid-liquid separation part is allowed to settle in a path provided separately from the upward flow part. It is characterized by returning to.

  Further, in the anaerobic treatment method of the present invention, the anaerobic sludge separated by the solid-liquid separation unit is allowed to settle down along a path provided separately from the upward flow part and returned downward from the waste water introduction part of the upward flow part. May be.

  Further, in the anaerobic treatment method of the present invention, the anaerobic sludge separated in the solid-liquid separation part is allowed to settle in a path provided separately from the upward flow part, and the anaerobic sludge is precipitated at the lower part of the upward flow part. It may be returned upward from the anaerobic sludge bed.

  Further, the anaerobic treatment method of the present invention is an anaerobic treatment method for treating wastewater using anaerobic sludge, and the wastewater is introduced from the wastewater introduction part to the lower part of the upward flow part containing the anaerobic sludge. Then, the introduced wastewater is anaerobically treated while flowing upward in the upward flow part, and the solid-liquid separation part provided at the upper part of the upward flow part is anaerobically treated and overflows the upper end of the upward flow part. The treated water and the suspended matter mixed in the treated water are separated, and the suspended material separated by the solid-liquid separation unit is allowed to settle in a path provided separately from the upward flow part. It is characterized by discharging to the outside.

  ADVANTAGE OF THE INVENTION According to this invention, the anaerobic processing apparatus and the anaerobic processing method which are easy to make the apparatus low-profile and size reduction can be provided.

  Embodiments of the present invention will be described below. In addition, the same code | symbol is used for the same element and the overlapping description is abbreviate | omitted.

  FIG. 1 is a cross-sectional view showing an anaerobic treatment apparatus 1. This anaerobic processing apparatus 1 is an anaerobic processing apparatus using a processing method such as a so-called UASB type or EGSB type. The anaerobic treatment apparatus 1 includes a treatment tank 3 and a waste water introduction unit 5 that introduces waste water W to be treated into the treatment tank 3.

  Hereinafter, the processing tank 3 will be described with reference to FIG. FIG. 2 is a perspective view of the treatment tank 3 having a cut surface cut in the vertical direction. However, in FIG. 2, an insertion port for inserting the waste water introduction part 5 and an insertion port for inserting the gas discharge pipe 21 (described later) are omitted. The treatment tank 3 has a quadrangular prism shape, and has an upper wall 4, a bottom wall 7, an outer wall 9, and an inner wall 11 that is provided inside the outer wall 9 so as to be separated from each other. The outer wall 9 is separated from the inner wall 11 and is provided so as to surround the inner wall 11, and a gap is provided between the outer wall 9 and the inner wall 11. The upper end 11 a of the inner wall 11 is opened without contacting the upper wall 4, and the lower end of the inner wall 11 is opened without contacting the bottom wall 7. The outer side wall 9 is provided so as to extend upward from the edge of the bottom wall 7. The upper end of the outer wall 9 is opened without contacting the upper wall 4. Further, the upper end of the outer wall 9 is slightly higher than the upper end 11 a of the inner wall 11. Hereinafter, the inner space R1 surrounded by the inner wall 11 is referred to as an inner space R1, and the space between the outer wall 9 and the inner wall 11 is referred to as a space R2.

  The intermediate wall 13 extends downward from the upper wall 4 toward the space R <b> 2 so as to be sandwiched between the inner wall 11 and the outer wall 9. The lower end of the intermediate wall 13 is at a position lower than the upper end 11 a of the inner wall 11 and the upper end of the outer wall 9. A trough portion 15 is provided on the outer wall of the outer side wall 9. The upper end of the trough portion 15 continues to the edge of the upper wall 4. A drain port 17 is formed through the side surface of the trough portion 15. A rectifying plate 19 is provided in the space R1. The rectifying plate 19 is composed of a plurality of cylindrical members having rectangular openings. The plurality of members are arranged so that their side surfaces are substantially parallel to the respective wall surfaces of the inner wall 11. Each member is arranged in a similar shape with one vertical axis as a central axis. That is, each of the above members has a coaxial rectangular shape in plan view.

  Refer to FIG. 1 again. The waste water introduction part 5 is provided in the lower part of the treatment tank 3 so as to pass through the outer wall 9 and the inner wall 11 from the outside of the treatment tank 3. The waste water introduction unit 5 introduces waste water W supplied from the outside into the space R1. The waste water introduction part 5 is provided with a number of water outlets 5a, and the waste water W is jetted upward from the water outlets 5a.

  The lower part of the space R1 is filled with granular sludge S (hereinafter simply referred to as “sludge S”), and methanogenic bacteria are present therein. The methanogen in the sludge S anaerobically treats the wastewater W introduced from the wastewater introduction unit 5, decomposes organic substances in the wastewater W, and generates gases such as methane gas and carbon dioxide gas. The treated waste water (hereinafter referred to as “treated water”) W1 is discharged to the outside of the treatment tank 3 through the drain port 17.

  An extraction port (extraction path) 24 is provided at the lower part of the side surface of the space R2. The extraction port 24 is connected to the cock 26, and when the cock 26 is opened, the sludge S and the suspended matter SS that have settled in the space R <b> 2 pass through the extraction port 24 and are discharged to the outside of the treatment tank 3.

  Hereinafter, the operation | movement at the time of the driving | operation of the anaerobic processing apparatus 1 is demonstrated. During operation of the anaerobic treatment apparatus 1, waste water W is always introduced from the waste water introduction unit 5 into the space R1. Since the waste water W is continuously introduced, the treatment tank 3 is filled with the waste water W (and the treated water W1) up to the height of the upper end of the outer wall 9, and the liquid level H is formed.

  The waste water W introduced from the waste water introduction part 5 is ejected upward from the outlet 5a, mixed with the sludge S, and subjected to anaerobic treatment with the sludge S. The gas generated by the anaerobic treatment becomes bubbles and rises in the space R1. Due to the ejection from the water outlet 5a and the rising of the bubbles, an upward flow is generated in the space R1, and the waste water W flows upward. Further, the flow of the waste water W is rectified in the vertical direction by the rectifying plate 19. Thus, the space R1 constitutes the upward flow portion, and the inner wall 11 constitutes the sidewall of the upward flow portion R1. Further, the upper end 11a of the side wall 11 constitutes the upper end of the upward flow portion R1. As the wastewater W flows upward in the space R <b> 1, the organic matter is decomposed by the sludge S, and the organic matter concentration decreases as it approaches the liquid level H. Therefore, most of the liquid in the vicinity of the liquid level H is treated water W1 having a low organic content.

  Part of the sludge (solid matter) S is lifted by the gas bubbles adhering thereto and reaches the liquid level H. While the sludge S is floating on the liquid surface H, gas bubbles are separated from the sludge S. Further, the sludge S gathers together while floating on the liquid surface H, and the particles become large and become granular. The gas away from the sludge S accumulates in the space between the liquid level H and the upper wall 4 and is discharged to the outside through the gas discharge pipe 21. The sludge S that floats over the liquid surface H and passes over the inner wall 11 is guided to the intermediate wall 13 together with the treated water W1, and is sandwiched between the intermediate wall 13 and the inner wall 11 together with the treated water W1 (hereinafter referred to as “channel R3”). Is settling toward the space R2. Thus, the intermediate wall 13 functions as a guide plate.

  Since the sludge S descending the flow path 3 is in a state where the gas bubbles are separated from each other, the sludge S easily settles down by gravity toward the space R2. Further, since part of the treated water W1 that has passed over the inner wall 11 flows into the space R2, the sludge S that settles in the space R2 is pushed away by the treated water W1 and smoothly settles in the space R2. The remaining treated water W1 passes over the upper end of the outer wall 9 through a gap between the intermediate wall 13 and the outer wall 9 (hereinafter referred to as “flow path R4”) and enters a space R5 surrounded by the trough portion 15. Overflowing. The treated water W1 overflowing into the space R5 is discharged to the outside of the treatment tank 3 through the drain port 17. The discharged treated water W1 is discharged after removing organic substances, nitrogen components, and phosphorus components by biological treatment, physicochemical treatment, etc. as necessary.

  Thus, the flow path R3, the flow path R4, and the intermediate wall 13 provided on the outer peripheral portion of the upper end 11a constitute a solid-liquid separation section 23 that separates the sludge S and the treated water W1.

  The sludge S that has settled in the space R2 reaches the bottom wall 7 and is returned below the wastewater introduction part 5 in the space R1 through the gap 25 between the bottom wall 7 and the inner wall 11. The sludge S returned to the space R1 contributes to the anaerobic treatment of the wastewater W introduced from the wastewater introduction unit 5 while rising again by the upward flow. Thus, the space R2 provided in the outer peripheral portion of the space R1 constitutes a fluid circulation path that guides the sludge S downward.

  The rising speed of the waste water W or the like in the space R1 is preferably set to 1 to 10 m / h, more preferably 2 to 6 m / h, from the viewpoint of good separation in the solid-liquid separation unit 23. .

  In this anaerobic processing apparatus 1, since the solid-liquid separation part 23 is integrally provided in a part of the processing tank 3, it is not necessary to provide a separate solid-liquid separation tank, and the installation space can be reduced. Moreover, the solid-liquid separation part 23 of the anaerobic processing apparatus 1 isolate | separates the sludge S from the treated water which overflowed the upper end 11a of space R1. For this reason, even if the sludge S reaches the uppermost portion of the space (upward flow portion) R1, it is separated from the treated water after that, so that the separation performance can be achieved regardless of the vertical height of the upward flow portion R1. Can be secured. Therefore, according to the said anaerobic processing apparatus, the height of the vertical direction of the upward flow part R1 can be suppressed, and the whole apparatus can be shortened. Moreover, since the said anaerobic processing apparatus 1 is providing the space R2 as a fluid circulation path | route, the sludge S returned downward is a path | route different from the rising sludge S, from the wastewater introduction part 5. Is also returned downward. Therefore, the separated sludge S and the rising sludge S do not coexist, and the sludge S accommodated in the space R1 is always switched up and down, and the activity of the sludge S is made uniform.

  Further, in the space R2 as the fluid circulation path, a downward flow is generated in the space R2 due to the influence of the upward flow due to the gas lift action of the gas generated in the space R1. Therefore, since the sludge S that settles in the space R2 is smoothly guided downward by gravity and a downward flow, for example, a pump for returning the sludge S is not necessary, and the sludge S that is in a granular shape at the liquid surface H is used. Does not cause the problem of being crushed by a pump or the like.

  Moreover, the said anaerobic processing apparatus 1 is provided with the solid-liquid separation part 23 in the outer peripheral part of the upper end of space R1. For this reason, the gas adhering to the sludge S in the form of bubbles is separated from the sludge S at the liquid level H in the upper central portion of the space R1. As a result, the sludge S loses buoyancy, sinks again, and is returned downward. In addition, the sludge S that does not settle here and overflows the end portion 11a is less affected by the buoyancy of the gas and easily settles. Therefore, the sludge S and the treated water W1 efficiently settle in the space R2. Well separated.

  In addition, the anaerobic treatment apparatus 1 is provided with the intermediate wall 13 so that the sludge S is efficiently introduced into the space R2 and efficiently guided downward. Moreover, since the anaerobic processing apparatus 1 has the baffle plate 19, the waste water W etc. flow smoothly in space R1.

  Subsequently, the operation at the time when the waste water W has a low concentration (for example, CODCr ≦ 1500 ppm) will be described. Note that description of points that overlap with the above description is omitted.

  When the low-concentration waste water W is introduced into the anaerobic treatment apparatus 1, since there is little gas generated in the anaerobic treatment in the space R1, there is little sludge S to which gas bubbles adhere and are lifted. For this reason, the sludge S is distributed below the center of the space R1 during operation, and there is little sludge S reaching the liquid level H. Since the operation is performed as described above, there is little sludge S reaching the liquid level H, and the solid matter separated in the solid-liquid separation unit 23 is mostly occupied by the suspended matter SS contained in the waste water W. .

  The suspended matter SS separated by the solid-liquid separation unit 23 is introduced into the space R2 and stays near the lower portion of the space R2. Since the suspended solid SS is contained in the waste water W and supplied into the treatment tank 3, the suspended solid SS near the lower portion of the space R2 gradually increases and the density increases. Therefore, the cock 26 is opened at every predetermined time, and the suspended solid SS retained in the vicinity of the space R2 is discharged from the extraction port 24 to the outside of the processing tank 3.

  The suspended matter SS contained in the waste water W is not suitable for anaerobic treatment and is continuously supplied, so that it accumulates in the treatment tank 3. According to the anaerobic treatment apparatus 1, since the extraction port 24 is provided, the accumulated solid matter can be discharged to the outside, and the suspended solid SS is accumulated excessively in the treatment tank 3. Can be prevented.

  Further, as described above, when the organic matter concentration of the waste water W to be treated is low, the generated gas is reduced. However, in the anaerobic treatment apparatus 1, the generated gas is supplied to the gas discharge pipe 21 provided on the upper wall 4. The gas is not removed except at the liquid level H. Therefore, according to the anaerobic processing apparatus 1, gas is not removed in the middle of the space R1, and an upward flow is formed by the gas lift effect even when the amount of generated gas is small. Therefore, the anaerobic treatment apparatus 1 can be suitably applied to the treatment of wastewater having a low organic matter concentration, for example, CODCr ≦ 1500 ppm.

  Hereinafter, the Example of the anaerobic processing apparatus 1 which concerns on above-described embodiment is demonstrated. In this example, the anaerobic treatment apparatus 1 was used to treat the wastewater W having a low concentration (CODCr = 1000 ppm). In an anaerobic treatment apparatus 1 having a treatment tank 3 having a diameter of 0.5 m, a tank effective height of 7 m, and an effective volume of 1 m 3, an organic wastewater having a CODCr of 1000 ppm is supplied from the wastewater introduction section 5 at a rate of 800 kg per hour, The anaerobic treatment was performed at a counterflow velocity of 4.0 m / h. The COD volumetric load of the treatment tank 3 was set to 18 to 20 kg / m3 / d, and the granular sludge was distributed below the center of the space R1. When continuous operation was performed for one month under the above conditions, there was almost no granule sludge discharged from the drain port 17, and the concentration of granule sludge in the tank was maintained almost constant, and good operation was possible.

  Next, an anaerobic treatment apparatus 1B according to another embodiment of the present invention will be described. FIG. 3 is a cross-sectional view showing the anaerobic treatment apparatus 1B. However, FIG. 3 shows a cross-sectional view in a state where the sludge S and the waste water W are not introduced into the apparatus. FIG. 4 shows a perspective view of the appearance of the anaerobic treatment apparatus 1B.

  The difference between the treatment tank 3B provided in the anaerobic treatment apparatus 1B and the treatment tank 3 is in the configuration of the space R2 used as the fluid circulation path. The space R <b> 2 in the processing tank 3 </ b> B is configured by a hollow portion inside the tubular member 31. The tubular member 31 extends from the lower end of the solid-liquid separation part 23 to the lower part of the inner wall 11 and is exposed to the outside of the inner wall 11. One end of the space R <b> 2 is connected to the flow path R <b> 3 and the flow path R <b> 4 via a pipe inlet 33 provided at the lower end of the solid-liquid separation unit 23. The other end of the space R2 is connected to the lower portion of the space R1 through a pipe outlet 35 provided at the lower portion of the inner wall 11. The pipe outlet 35 is provided below the waste water introduction part 5.

  During operation of the anaerobic treatment apparatus 1B, the sludge S that has passed over the upper end 11a of the inner wall 11 is guided by the intermediate wall 13 and settles, then enters the pipe inlet 33, and is a hollow portion (space R2) of the tubular member 31. To settle. The sludge S that has settled in the space R2 is returned to the lower part of the space R1 from the pipe outlet 35 again.

  As in the anaerobic treatment apparatus 1B, even if the fluid circulation path is constituted by the hollow portion of the tubular member, the same operation and effect as the anaerobic treatment apparatus 1 can be obtained.

  Subsequently, an anaerobic treatment apparatus 1D according to still another embodiment of the present invention will be described. FIG. 5 is a cross-sectional view showing an anaerobic treatment apparatus 1D. This anaerobic processing apparatus 1D is different from the above-described anaerobic processing apparatus 1B in that the position of the pipe outlet 65 that connects the space (upward flow portion) R1 and the space (fluid circulation path) R2 is provided. The pipe outlet 65 is provided above the waste water introduction part 5. Except for this difference, the anaerobic processing apparatus 1D has the same configuration as the anaerobic processing apparatus 1B, and the same or equivalent elements are denoted by the same reference numerals.

  In the lower part of the space R1 of the anaerobic treatment apparatus 1D, the filled sludge S is precipitated by its own weight, and the sludge S (anaerobic sludge bed) Rs is formed by the precipitated sludge S, and above the sludge bed Rs. Is formed with a supernatant portion Rt with a small amount of solid matter. The pipe outlet 65 is provided at the position of the supernatant portion Rt above the sludge bed Rs in the space R1, and the solid matter settled in the space R2 is returned to the space R in the supernatant portion Rt. Become. Therefore, the solid matter that settles in the space R2 is smoothly returned to the supernatant portion Rt without receiving the resistance of the sludge S in the sludge bed Rs, and the solid matter is prevented from stagnating in the space R2. Of the solid matter returned to the supernatant portion Rt, the sludge S that is easy to sink is lowered by its own weight and returned to the sludge bed Rs. Further, solids (for example, suspended substances) other than the sludge S rise again due to the upward flow of the supernatant Rt, and finally circulate between the space R1 and the space R2, and finally discharged to the outside through the extraction port 24. Is done. For example, when the height of the anaerobic treatment apparatus 1D is about 8 m, the sludge S is filled so that the sludge bed Rs is formed with a thickness of about 3 to 4 m from the bottom, and the position about 5 m from the bottom. Is provided with a tube outlet 65. Even with such an anaerobic treatment apparatus 1D, the separation performance can be ensured regardless of the vertical height of the upward flow portion R1, so that the vertical height of the upward flow portion R1 can be suppressed. The overall height of the apparatus can be reduced.

  In the anaerobic treatment apparatus 1B, the tubular member 31 is provided so as to be exposed to the outside. For example, a tubular member may be provided in the space R1 serving as the upward flow portion. An anaerobic treatment apparatus 1C is shown as such an embodiment. FIG. 6 is a cross-sectional view of the anaerobic treatment apparatus 1C. The tubular member 51 extends from the lower end of the solid-liquid separator 23 and extends to the lower part of the space R1 through the inside of the space R1 surrounded by the housing 61. A hollow portion of the tubular member 51 constitutes a space R2 as a fluid circulation path. One end of the space R2 is connected to the flow path R3 and the flow path R4 via a pipe inlet 53 provided at the lower end of the solid-liquid separation unit 23. The other end of the space R2 is connected to the lower portion of the space R1 through a tube outlet 55 opened to the space R1. The pipe outlet 55 is provided below the waste water introduction part 5.

  In the anaerobic treatment apparatus 1 </ b> C, the tubular member 51 is provided in the space R <b> 1, and thus the casing 61 that surrounds the space R <b> 1 extends to the same surface as the outer wall of the trough portion 15. For this reason, a smooth upward flow is not formed in the space immediately below the solid-liquid separation part 23 and the space directly below the trough part 15 in the space R1. For this reason, in the anaerobic treatment apparatus 1 </ b> C, the lower part of the inner wall 11 has a shape of a truncated quadrangular pyramid in which the lower part spreads downward, and the upward flow is smoothly directed toward the uppermost part of the inner wall 11. It comes to flow. In this case, since the space immediately below the solid-liquid separation part 23 and the space immediately below the trough part 15 are dead spaces, a support beam 59 for improving the strength of the treatment tank 3C may be provided in this space. Like this anaerobic treatment apparatus 1C, even if a tubular member is provided in the upward flow portion R1, the same operation and effect as the anaerobic treatment apparatus 1B can be obtained.

  Similarly, in the anaerobic treatment apparatus 1 </ b> C, the tube outlet 55 may be provided at a position above the sludge bed by shortening the tubular member 51. If it does in this way, the effect | action and effect similar to anaerobic processing apparatus 1D will be acquired.

  Further, the above-described configurations can be combined with each other without departing from the spirit of the present invention.

It is sectional drawing which shows an anaerobic processing apparatus. It is a perspective view of the processing tank of the state cut | disconnected in the perpendicular direction. It is sectional drawing which shows another anaerobic processing apparatus. It is a perspective view which shows another anaerobic processing apparatus. It is sectional drawing which shows another anaerobic processing apparatus. It is sectional drawing which shows another anaerobic processing apparatus. It is a figure which shows the conventional anaerobic processing apparatus.

Explanation of symbols

  1, 1B, 1C, 1D ... anaerobic treatment device, 3, 3B, 3C ... treatment tank, R1 ... space (upward flow part), R2 ... space (fluid circulation path), R3, R4, R5 ... flow path DESCRIPTION OF SYMBOLS 5 ... Waste water introduction part, 9 ... Outer wall, 11 ... Inner side wall, 11a ... Upper end, 13 ... Intermediate wall, 15 ... Trough part, 17 ... Drain port, 19 ... Current plate, 23 ... Solid-liquid separation part, 31, 51 ... Tubular member, S ... Sludge, Rs ... Sludge bed, SS ... Suspended matter, W ... Waste water, W1 ... Treated water.

Claims (13)

An anaerobic treatment device that treats wastewater using anaerobic sludge,
An upflow section having a side wall defining a space for containing the anaerobic sludge, and performing anaerobic treatment by flowing the wastewater upward through the anaerobic sludge;
A wastewater introduction part for introducing the wastewater into the upward flow part;
A solid-liquid separation unit that separates solids from treated water that has been treated in the upward flow part and overflowed the upper end of the upward flow part;
A fluid circulation path that connects the solid-liquid separation part and the upward flow part, and guides the solid separated by the solid-liquid separation part downward;
An anaerobic treatment apparatus equipped with. The fluid circulation path is:
The anaerobic treatment apparatus according to claim 1, wherein the solid-liquid separation unit is connected to a lower side than the waste water introduction unit of the upward flow unit. The fluid circulation path is:
The anaerobic treatment apparatus according to claim 1, wherein an upper part of the solid-liquid separation unit and an upper part of the anaerobic sludge bed formed by precipitation of the anaerobic sludge are connected to a lower part of the upward flow unit. The upper end of the upward flow portion includes the upper end of the side wall,
The solid-liquid separator is
The anaerobic treatment apparatus according to claim 1, wherein the anaerobic treatment apparatus is provided on an outer peripheral portion of the upward flow portion so as to surround an upper end of the upward flow portion. The solid-liquid separator is
A guide plate that is spaced from the upward flow portion and is provided to surround the upper end of the upward flow portion;
The guide plate is
The organic sludge volume reducing device according to claim 4, wherein the solid material that has flowed over the upper end of the upward flow portion is guided to the fluid circulation path. The fluid circulation path is:
The gap portion sandwiched between the side wall of the upward flow portion and another side wall provided so as to surround the side wall is included. The anaerobic processing apparatus described in 1. The fluid circulation path is:
The anaerobic treatment apparatus according to any one of claims 1 to 5, further comprising a hollow portion of a tubular member extending from the solid-liquid separation unit to a position below the wastewater introduction unit.   The rectifier plate according to claim 1, further comprising a rectifying plate that is provided above the wastewater introduction portion in the upward flow portion and rectifies the flow of the wastewater in the upward flow portion in the vertical direction. The anaerobic processing apparatus according to any one of the above. The anaerobic treatment apparatus according to any one of claims 1 to 8, further comprising a drawing path for discharging solid matter that settles in the fluid circulation path to the outside of the upward flow portion. An anaerobic treatment method for treating wastewater using anaerobic sludge,
Introducing waste water from the waste water introduction part to the lower part of the upward flow part containing the anaerobic sludge,
Anaerobic treatment while flowing the waste water introduced upward in the upward flow part,
In the solid-liquid separation part provided at the upper part of the upward flow part, the treated water that has been anaerobically treated and overflowed the upper end of the upward flow part is separated from the anaerobic sludge mixed in the treated water. And
An anaerobic treatment method, wherein the anaerobic sludge separated by the solid-liquid separation part is returned to the upward flow part by sinking a path provided separately from the upward flow part.   The anaerobic sludge separated by the solid-liquid separation part is caused to settle down a path provided separately from the upward flow part and return downward from the waste water introduction part of the upward flow part. Item 11. The anaerobic treatment method according to Item 10.   The anaerobic sludge bed in which the anaerobic sludge separated by the solid-liquid separation part is settled in a path provided separately from the upward flow part and the anaerobic sludge is precipitated at the lower part of the upward flow part. The anaerobic treatment method according to claim 10, wherein the anaerobic treatment method is returned upward. An anaerobic treatment method for treating wastewater using anaerobic sludge,
Introducing waste water from the waste water introduction part to the lower part of the upward flow part containing the anaerobic sludge,
Anaerobic treatment while flowing the waste water introduced upward in the upward flow part,
In the solid-liquid separator provided at the upper part of the upward flow part, the treated water that has been anaerobically treated and overflowed the upper end of the upward flow part is separated from the suspended matter mixed in the treated water. ,
An anaerobic treatment method characterized in that the suspended substance separated by the solid-liquid separation part is discharged to the outside of the upward flow part by settling a path provided separately from the upward flow part.

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