JP2013226512A - Anaerobic treatment apparatus, and anaerobic treatment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anaerobic treatment apparatus and an anaerobic treatment method capable of sufficiently washing the surface of a separation membrane and capable of exhibiting stable filtering capacity.SOLUTION: In an anaerobic treatment apparatus, a granule sludge bed GF due to granule sludge G is formed to the lower part in a tank 1 and water to be treated is introduced into the tank 1 from the lower part to form an ascending stream to decompose the organic components in the water to be treated by the contact with the granule sludge G. The treated water is separated from the granule sludge G by the separation membrane 2 immersed in the granule sludge bed GF and, by the biogas generated at this time to rise and the water to be treated upwardly fluidized at this time, the fluidization of the granule sludge G is generated at all parts to allow not only the shearing force due to the fluidizing granule sludge G but also the rising biogas to act on the surface 2a of the separation membrane 2 immersed in the granule sludge bed GF.

Description

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

  Conventionally, UASB (Upflow Anaerobic Sludge Blanket) treatment that has granulated anaerobic sludge that is agglomerated and granulated by anaerobic microorganisms as treatment equipment for treated water containing organic components An apparatus is known (see, for example, Patent Document 1). This treatment device holds the granule sludge bed with granule sludge in the lower part of the tank and introduces the water to be treated from the lower part of the tank, so that the water to be treated flows upward while making contact with the granule sludge. The organic component of the water to be treated is decomposed with granule sludge.

  Here, in the anaerobic treatment apparatus, a three-phase separation part (gas-solid-liquid separation part) is provided above the granular sludge bed, and biogas generated by anaerobic treatment with granule sludge in the three-phase separation part. In general, the sludge and the treated water subjected to anaerobic treatment are separated. However, in order to increase the cost and complexity of the structure, in Patent Document 2 below, a separation membrane is used instead of the three-phase separation unit. (Membrane separation device) is used to simplify the structure.

  Specifically, a separation membrane is installed above the granular sludge bed in the tank, and the treated water is separated into solid and liquid by this separation membrane and taken out of the tank. In addition, in order to suppress clogging of the membrane, the membrane surface of the separation membrane is gas-washed with biogas generated and raised by anaerobic treatment.

Japanese Patent Laid-Open No. 9-1178 JP 2009-154156 A

  However, the apparatus described in Patent Document 2 has a problem in that the membrane surface of the separation membrane is not sufficiently cleaned, and the filtration capacity is quickly reduced.

  The present invention has been made to solve such problems, and provides an anaerobic treatment apparatus and an anaerobic treatment method capable of sufficiently washing the membrane surface of a separation membrane and exhibiting stable filtration ability. For the purpose.

  The anaerobic treatment apparatus according to the present invention includes a granular sludge bed made of granular sludge in the lower part of the tank, introduces treated water containing organic components from the lower part of the tank, and converts the treated water into granular sludge. An anaerobic treatment apparatus that performs anaerobic treatment by flowing while contacting is characterized by including a separation membrane that is immersed in a granular sludge bed and separates the granular sludge from the treated water.

  In addition, the anaerobic treatment method according to the present invention comprises a granule sludge bed with granular sludge in the lower part of the tank, introduces treated water containing organic components from the lower part of the tank, and the treated water is granulated. In an anaerobic treatment method in which anaerobic treatment is performed by flowing while making contact with sludge, a separation membrane for solid-liquid separation of granular sludge and treated water is immersed in a granular sludge bed.

  According to such an anaerobic treatment apparatus and anaerobic treatment method, a granular sludge bed with granular sludge is formed in the lower part of the tank, and the water to be treated containing organic components is introduced from the lower part of the tank. An upward flow is formed, organic components in the water to be treated are decomposed by contact with the granular sludge, and the treated water is solid-liquid separated from the granular sludge by a separation membrane immersed in the granular sludge bed. . At this time, biogas containing methane is generated and decomposed due to decomposition of organic components, and the flow of granular sludge is generated in the tank by the upwardly treated water and biogas. Therefore, the membrane surface of the separation membrane immersed in the granular sludge bed is subjected to a shearing force due to the flowing granular granule sludge, and in addition, a cleaning force due to the rising biogas also acts. The membrane surface can be washed sufficiently and stable filtration ability can be exhibited.

  Specific examples of the separation membrane that preferably exhibits the above action include an external pressure type flat membrane, an external pressure type hollow fiber membrane, and an internal pressure type tubular membrane.

  According to the present invention as described above, the membrane surface of the separation membrane can be sufficiently washed, and stable filtration ability can be exhibited.

It is a schematic block diagram which shows the anaerobic processing apparatus which employ | adopted the anaerobic processing method which concerns on embodiment of this invention.

  Hereinafter, a preferred embodiment of an anaerobic treatment apparatus employing an anaerobic treatment method according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an anaerobic treatment apparatus employing an anaerobic treatment method according to an embodiment of the present invention.

  As shown in FIG. 1, the anaerobic processing apparatus 100 is the UASB type anaerobic processing apparatus mentioned above, and is equipped with the tank 1 which is an anaerobic reaction tank here. Here, the tank 1 has a shape in which the upper and lower ends of the cylinder are closed. And the granular sludge G is accommodated in the lower part in the tank 1, and the granular sludge bed GF is formed. In addition, the tank 1 is not limited to a cylindrical shape, and may be a rectangular tube shape.

  The introduction pipe 7 for introducing the water to be treated containing organic components into the tank 1 is provided with a pump for sending the water to be treated into the tank 1 in the pipe line outside the tank 1, and at the lower part of the tank 1. The tank 1 is provided so as to be inserted from the outside of the tank 1 through the tank peripheral wall.

  The introduction pipe 7 includes a water outlet 7 a for ejecting the water to be treated in the introduction pipe 7 in the tank 1. The water outlet 7 a is configured in a nozzle shape and is opened upward in the introduction pipe 7 in order to eject the water to be treated upward, and a plurality of the outlets 7 a are provided along the axis of the introduction pipe 7.

  In addition, a gas pipe 10 for taking out biogas containing methane generated by anaerobic treatment with granule sludge G to the outside of the tank 1 is provided in the upper part of the tank 1 so as to pass through the upper wall of the tank. .

  Here, particularly in the present embodiment, the separation membrane unit 11 is disposed so as to be immersed in the granular sludge bed GF and positioned above the water outlet 7 a of the introduction pipe 7. The separation membrane unit 11 includes a plurality of separation membranes 2.

  The separation membrane 2 is a separation membrane for solid-liquid separation of the treated water from the anaerobic treatment and the granular sludge G, and here, as an especially preferable example, an external pressure type flat membrane is used. The separation membrane unit 11 is a flat membrane unit in which a plurality of flat membranes 2 are juxtaposed in the horizontal direction (perpendicular to the plane of FIG. 1) and held by a frame body 12.

  Here, the flat film of the present embodiment is a film formed into a flat shape or a sheet shape, and may be usually used for MBR (Membrane Bio Reactor), and may be a polyolefin resin such as chlorinated polyethylene, Examples thereof include a porous membrane formed from polyvinylidene fluoride resin, polytetrafluoroethylene resin, polypropylene, polyethylene, polystyrene, polyacrylonitrile, cellulose acetate, polysulfone, polyethersulfone, ceramic and the like.

  In the upper part of the flat membrane 2, a water collection port 13 is provided for collecting the treated water that is solid-liquid separated from the granular sludge G in the flat membrane 2 and flows in the flat membrane 2. A water collecting pipe 14 is connected to the water collecting port 13 of the membrane 2. And the outlet pipe 9 for taking out treated water out of the tank 1 is connected to the water collecting pipe 14. The lead-out pipe 9 is provided so as to pass through the tank peripheral wall from the tank 1 and lead out to the outside, and a pump for sending treated water to the outside of the tank 1 is provided in a pipe line outside the tank 1.

  In the external pressure type flat membrane 2 of the present embodiment, the treated water flows from the outer side of the flat membrane 2 to the inner side (perpendicular to the plane of FIG. 1) by driving the pump of the outlet pipe 9. Is a system in which pressure is applied so as to form a flow led out of the tank 1 from the water collecting port 13 at the upper part of the flow through the outlet pipe 9, that is, a negative pressure is generated by driving the pump. It is a method to pull the treated water. In addition, it is good also as a system which pushes in with a positive pressure and guides out treated water through the lead-out pipe 9.

  In addition, an acid generation tank 3 into which organic wastewater that is raw water flows is connected to the upstream side of the introduction pipe 7. This acid generation tank 3 organically oxidizes the inflowed organic waste water in order to stably perform the anaerobic treatment in the subsequent tank 1. A return pipe 8 that returns a part of the treated water in the tank 1 is connected to the acid generation tank 3.

  According to the anaerobic treatment apparatus 100 having such a configuration, the organic waste water is organically oxidized in the acid generation tank 3, and the organically treated water (acetic acid) is introduced into the tank 1 through the introduction pipe 7. And is ejected from the water outlet 7a. As the water to be treated is ejected upward, an upward flow of the water to be treated is formed and flows upward. In accordance with this flow, the organic components in the water to be treated are decomposed in contact with the granular sludge G forming the granular sludge bed GF (anaerobic treatment), and biogas containing methane is generated and rises.

  On the other hand, in the flat membrane unit 11 immersed in the granule sludge bed GF, the granule sludge G and the treated water by anaerobic treatment are solid-liquid separated by the flat membrane 2.

  At this time, in the tank 1, the flow of the granular sludge G occurs everywhere due to the upwardly treated water and biogas. Therefore, the shearing force by the flowing granular granule sludge G acts on the membrane surface 2a of the flat membrane 2 immersed in the granule sludge bed GF, and the membrane surface 2a is washed. Furthermore, the membrane surface 2a is also cleaned by the rising biogas, so that the membrane surface 2a is further cleaned.

  Then, the treated water separated by the flat membrane 2 is taken out through the lead-out pipe 9, and the biogas rising in the tank 1 is taken out through the gas pipe 10 to be treated water in the tank 1. A part of is returned to the acid generation tank 3 through the return pipe 8.

  Thus, in the anaerobic treatment apparatus 100 of the present embodiment, the organic components in the water to be treated are decomposed by contact with the granule sludge G, and the treated water is immersed in the granule sludge bed GF. The flat membrane 2 which is a membrane separates the solid sludge G from the granular sludge G, while the membrane surface 2 of the flat membrane 2 has a granular shape which flows according to the upwardly treated water and biogas. Since the shearing force of the granular sludge G is applied, and the cleaning power by the rising biogas is also applied, the membrane surface 2a of the flat membrane 2 can be sufficiently cleaned, and a stable filtration ability can be exhibited.

  In the figure, the granular granule sludge G is exaggerated only on the membrane surface 2a of the flat membrane 2 in order to show how the granular granule sludge G cleans the membrane surface 2a of the flat membrane 2. In practice, however, a large number of granular sludge G that is denser than the figure forms the granular sludge bed GF and cleans the membrane surface 2a of the flat membrane 2.

  Incidentally, in the apparatus described in Japanese Patent Application Laid-Open No. 2009-154156 described in the related art, only the cleaning power by the weak biogas (bubbles) acts as compared with the cleaning power by the shearing force of the flowing granular granular sludge G. In addition, since the number (the number of bubbles) is overwhelmingly smaller than that of granular granule sludge G and cannot be obtained stably, the membrane surface 2a of the flat membrane (separation membrane) 2 is sufficiently formed. It cannot be washed.

  As described above, the present invention has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment. For example, in the above embodiment, the flat plate 2 of the external pressure type is particularly preferable. Although it is used as a separation membrane, an external pressure type hollow fiber membrane may be used instead. Furthermore, an internal pressure type tubular membrane (granule sludge flows in the tube of the tubular membrane and the treated water flows inside the tube). It is also possible to use one that applies pressure so as to flow and separate from the surface toward the outer peripheral surface of the pipe. In short, it may be soaked in the granular sludge bed GF.

  Moreover, in the said embodiment, in order to perform anaerobic treatment stably, the to-be-processed water which carried out the organic oxidation of the organic waste water in the acid generation tank 3 of the front | former stage is introduce | transduced in the tank 1, However, Organic What is necessary is just a to-be-processed water containing organic components, such as a waste_water | drain.

  Moreover, in the said embodiment, although the anaerobic processing apparatus 100 is made into the UASB type anaerobic processing apparatus, the contact efficiency with to-be-processed water is further expanded by further promoting the granulation of the granular sludge bed GF. Of course, it can also be applied to an EGSB (Expanded Granular Sludge Bed) treatment device that improves the water content. In short, a granule sludge bed GF is provided in the lower part of the tank 1, and organic components are contained. It can apply to the anaerobic processing apparatus which introduce | transduces the to-be-processed water containing from the lower part in the tank 1, and makes it flow while making the said treated water contact the granule sludge G.

  DESCRIPTION OF SYMBOLS 1 ... Tank, 2 ... Flat membrane (separation membrane), 2a ... Membrane surface, 7 ... Introducing pipe, 100 ... Anaerobic processing apparatus, G ... Granule sludge, GF ... Granule sludge bed.

Claims (3)

By providing a granular sludge bed with granular sludge in the lower part of the tank, introducing treated water containing organic components from the lower part of the tank, and flowing the treated water in contact with the granular sludge In the anaerobic processing device for anaerobic processing,
An anaerobic treatment apparatus comprising a separation membrane that is immersed in the granule sludge bed and separates the granule sludge from the treated water.   The anaerobic treatment apparatus according to claim 1, wherein the separation membrane is an external pressure type flat membrane, an external pressure type hollow fiber membrane, or an internal pressure type tubular membrane. By providing a granular sludge bed with granular sludge in the lower part of the tank, introducing treated water containing organic components from the lower part of the tank, and flowing the treated water in contact with the granular sludge In the anaerobic treatment method for anaerobic treatment,
An anaerobic treatment method, wherein a separation membrane for solid-liquid separation of the granule sludge and treated water is immersed in the granule sludge bed.

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