TW201343567A - Oscillating bed support, and method and device for biologically treating organic wastewater using the oscillating bed support - Google Patents

Abstract

To provide a microorganism-retaining oscillating bed support, and a method and device for biologically treating organic wastewater using the oscillating bed support where, in a biological treatment involving the use of a feeding action performed by microorganisms, the oscillating bed support readily retains the microorganisms and is capable of forming a sludge that is readily separated into a solid and liquid. The microorganism-retaining oscillating bed support comprises a plastic foam sheet. An organic wastewater is introduced into a first biological treatment tank 41 and a bacterially assisted biological treatment is performed. A first biologically treated water containing dispersed bacteria from the first biological treatment tank 41 is delivered into a second biological treatment tank 42, and a second biologically treated water is obtained and is subjected to solid-liquid separation. This microorganism-retaining oscillating bed support 50 is provided to the second biological treatment tank 42.

Description

Swinging carrier, biological treatment device and method for organic drainage using the oscillating carrier

The present invention relates to an oscillating carrier for maintaining a small animal which is easy to hold a small animal and which can form a sludge having good sedimentation property in the biological treatment of the organic drainage using the predation action of the micro animal, and the organic carrier using the oscillating carrier Biological treatment device for biological drainage and biological treatment method.

The activated sludge method used in the biological treatment of organic wastewater is widely used in dirty water treatment or industrial wastewater treatment because of its advantages in good water quality and easy maintenance. However, since the BOD volume load in the activated sludge process is usually about 0.5 to 0.8 kg/m ³ /d, a large application area is required. In addition, 20 to 40% of the decomposed BOD is converted into bacteria, that is, sludge, so a large amount of excess sludge is produced.

As a method of performing high-load treatment on organic drainage, a fluidized bed method in which a carrier is added is known. In this method, the BOD volume load of 3 kg/m ³ /d or more can be operated. However, the amount of sludge produced in this method is about 30 to 50% of the decomposition BOD, which is more than the general activated sludge method.

Japanese Patent Publication No. 1 to 5 discloses a method of first oxidatively decomposing an organic substance contained in a wastewater into a non-aggregating bacterium by biologically treating organic drainage in a first biological treatment tank. After the cells are removed by the micro-animals in the second biological treatment tank, it is possible to reduce the excess sludge. Further, in this method, high-load operation can be performed, and the treatment efficiency of the activated sludge method can be improved. rate. In the present invention, the term "micro animal" means a protozoan and a metazoan in a microorganism.

However, in the prior art, a swinging carrier composed of a fiber is known as a carrier for retaining bacteria (for example, Patent Documents 6 to 9), and a method of unitizing such a carrier has also been proposed (for example, Patent Document 10). . However, the previous oscillating carrier has a shape for the purpose of bacterial adhesion and sludge detachment, and it has not been considered as a place for feeding and ovulation of tiny animals. Therefore, even if the conventional fibrous oscillating carrier is used as a carrier for micro animal holding, there is a problem that the micro-animals are unstable and cannot preferentially proliferate the micro-animals effective for the treatment.

In other words, in the biological treatment tank for biological treatment by the predation action of tiny animals, not only the dispersed bacteria are effectively ingested, but also the solid-liquid separation property of the sludge and the filtration predatory type which contributes to the improvement of the treatment water quality. Animals, and aggregated predatory micro-animals that can prey on fibrillated sludge also proliferate. The latter floats on the side while preying on the fibrinated sludge. Therefore, when the micro animal is prioritized, the sludge is eaten indiscriminately and becomes a sludge in which the fine fiber waste is scattered. In the case of membrane separation treatment of biologically treated water, the lint becomes a cause of clogging of the mesh, and when the agglutination treatment biological treatment water is sedimented and separated, the lint is also a problem of a large amount of aggregation and a poor solid-liquid separation property. main reason.

Therefore, in the biological treatment tank for predation of microscopic animals, it is necessary to suppress aggregated predatory micro- animals, so that the filter-prey micro- animals are preferentially proliferated, but in the prior art, the current situation has not been proposed as such a filter-prey type. The device for the birth of small animals and the place for spawning.

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2008-36580

[Patent Document 2] International Publication WO2007-088860 Booklet

[Patent Document 3] Japanese Patent Laid-Open No. 2006-51414

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2007-326067

[Patent Document 5] Japanese Patent Laid-Open Publication No. 2009-202115

[Patent Document 6] Japanese Patent Laid-Open Publication No. 2007-196221

[Patent Document 7] Japanese Patent Laid-Open Publication No. 2002-136986

[Patent Document 8] Japanese Patent Laid-Open Publication No. 2007-175686

[Patent Document 9] Japanese Patent Laid-Open Publication No. 2004-167361

[Patent Document 10] Japanese Patent Laid-Open Publication No. 2004-358320

An object of the present invention is to provide a swinging carrier which is capable of retaining microscopic animals and capable of forming sludge having good solid-liquid separation property in biological treatment using a predatory action of microscopic animals, and biological treatment of organic drainage using the oscillating carrier Tanks, biological treatment devices, and biological treatment methods.

In order to solve the above problems, the inventors of the present invention have made intensive studies and found that in order to maintain a small animal, it is preferable to use a fixed bed carrier having a swinging property instead of a fluidized bed carrier as the swinging carrier. The sheet of foam material is most suitable.

The present invention is based on the knowledge and insights described above, and the gist of the first aspect is as follows: a swinging carrier of a first form, which is a swinging carrier for keeping small animals held in a biological treatment tank in biological processing of tiny animals. , It is characterized in that the oscillating carrier comprises a sheet of foamed plastic.

The swinging carrier of the second aspect is the first aspect, wherein the length of the sheet material in the depth direction (long direction) of the biological treatment tank is 100 to 400 cm, and the length in the short direction is 5 to 200cm, thickness is 0.5~5cm.

A swinging carrier according to a third aspect is the first or second aspect, wherein the sheet material has at least two faces having an apparent surface area of 500 cm ² or more.

The oscillating carrier according to the fourth aspect of the present invention, wherein the foam has a number of units of 25 mm or more in a range of 25 mm in length and has a number of units of 5 or more/25 mm and 125 or less/25 mm. The average pore size of the unit is 0.05~10mm.

A swinging carrier according to a fifth aspect of the invention, wherein the sheet material is made of a flexible polyurethane foam.

The biological treatment tank for organic drainage according to the sixth aspect, which is characterized in that the organic material in the organic drainage is removed, and the oscillating carrier for holding a small animal according to any one of the first to fifth aspects is provided.

The biological treatment method for organic drainage according to the seventh aspect, which is characterized in that the organic substance in the organic drainage is removed, and the oscillating carrier for holding the small animal according to any one of the first to fifth aspects is provided. The biological treatment tank flows into the organic drainage.

The eighth aspect of the organic drainage biological treatment device comprises an aerobic biological treatment tank which is a plurality of layers of two or more layers, and is guided to the first biological treatment tank. The organic wastewater is subjected to biological treatment by bacteria, and the first biologically treated water containing the bacteria in the dispersed state of the first biological treatment tank is circulated into the biological treatment tank after the second biological treatment tank, and biological treatment is performed. The at least one biological treatment tank after the second biological treatment tank is the biological treatment tank according to the sixth aspect.

A biological treatment method for organic drainage according to a ninth aspect, wherein the organic wastewater is introduced into the first biological treatment tank which is a two-layer or more multilayer aerobic biological treatment tank, and the biological treatment by the bacteria is carried out The first biological treatment water of the bacteria in the dispersed state of the first biological treatment tank is circulated into the biological treatment tank after the second biological treatment tank, and is subjected to biological treatment, wherein the biological treatment tank according to the sixth aspect is used. As at least one biological treatment tank after the second biological treatment tank.

The foamed sheet material constituting the oscillating carrier of the present invention is water-swellable if it is placed in water, and therefore has appropriate flexibility and is suitable for upward flow due to water flow or aeration flowing into the biological treatment tank. Swing to form a swinging fixed bed. The water-swellable foamed plastic sheet has a sufficiently large surface area to stably hold tiny animals, particularly filter-prey micro-animals, and promote their growth. Therefore, by using the oscillating carrier of the present invention, a swinging fixed bed of a micro animal holding carrier can be formed in the biological treatment tank, and the microscopic animals can be kept at a high concentration in the biological treatment tank, thereby improving the biological treatment efficiency.

In addition, with the oscillating carrier, it is preferred to filter the predatory type micro Since the animal is proliferated, it is possible to form a sludge having a good solid-liquid separation property. Therefore, when the biological treatment water is solid-liquid separated by a membrane separation device, the mesh of the separation membrane is prevented from being clogged, and the membrane separation can be stably performed for a long period of time. In addition, when the biological treatment water is agglomerated and the solid-liquid separation is carried out by using a sedimentation tank or a pressurized floating tank, the amount of the aggregating agent can be reduced, and stable sedimentation can be performed even in the sedimentation tank of the sludge returning method. Mud interface management.

Embodiments of the present invention will be described in detail below with reference to the drawings.

[Swinging carrier]

First, an embodiment of the swinging carrier of the present invention will be described with reference to Figs.

1(a) and 1(b) are perspective views showing an example of an embodiment of the oscillating carrier of the present invention, wherein (a) shows a sheet 1 made of foam as a main body of the oscillating carrier, and (b) shows a pattern of (b) The jig 2 is attached to the sheet 1.

Preferably, the oscillating carrier of the present invention is provided with a rectangular plate-like or elongated sheet of foamed plastic as shown in Fig. 1(a), and is usually as shown in Fig. 1(b). The jig 2 is attached to each of the short side portions (short-direction edge portions) of the sheet 1, and the sheet surface is erected so as to be in the depth direction of the biological treatment tank, and is placed in the biological treatment tank. The jig 2 may be made of metal, cloth, plastic or the like, and is not limited as long as the sheet 1 is fixed to the biological treatment tank, and the fixing can be strengthened for the tensile stress. Also, in order to further improve the mechanical strength, it is preferable to use one or more jigs 2 The two short side portions of the sheet 1 are held and fixed by a fastening tool or the like (for example, an adhesive, a wire, a belt, a fixing screw, or the like).

Preferably, the sheet 1 is suitable for the broad surface area of the small animal to lay eggs and grow (the so-called "apparent surface area" means the appearance of the sheet of the inner surface area of the porous foam unit which does not comprise the foamed plastic sheet. The sheet of the outer surface area is preferably a long side in which the biological treatment tank provided with the oscillating carrier is in the depth direction (hereinafter, the direction is sometimes referred to as "long direction"). 1a of a length L ₁ (however, in FIG. 1 (b) above, the clamp 2 is provided a sheet of usage, is not the length of the jig becomes 1 (b) of a length L ₁ of FIG. 2 coverage) is 100 ~ 400cm The short side 1b in the short direction orthogonal to the long side 1a has a length L ₂ of 5 to 200 cm and a thickness d of 0.5 to 5 cm. Further, the handling properties, suitability for consideration of the angle of the biological treatment tank, is preferred, L _2: L ratio of _a length L _2: L ₁ = _1: 1 to about 80.

The lengths L ₁ and L _{2 of the} sheet 1 affect the apparent surface area of the carrier, and the larger the area, the larger the number of growth of the small animals held, and therefore, it is suitable. However, the depth direction length L ₁ of the biological treatment tank in which the oscillating carrier is provided is caused to flow upward and downward by aeration, and has no influence on the fluidity of water. Therefore, it is not particularly limited, and the length in the short direction is The material width) L ₂ affects the fluidity of water. Therefore, the length L _{2 of the} sheet in the short direction is set to 5 to 200 cm as described above, and particularly preferably 5 to 100 cm. With respect to the sheet width (short direction length), when the width of the biological treatment tank in which the oscillating carrier is provided is large, as will be described later, it is preferable to increase the number of sheets provided in the biological treatment tank to prevent short-circuit flow.

Moreover, when the thickness d of the sheet 1 is too thick, the water permeability inside the sheet is lowered, so that it is liable to cause a problem of internal bacterial spoilage. Therefore, it is preferable that the thickness d of the sheet 1 is made thinner in order to secure the necessary strength, and it is preferable to set it as 0.5 to 5 cm as described above.

Further, in the same manner, the sheet 1 preferably has at least two surfaces having an apparent surface area of 500 cm ² or more in order to form a sheet suitable for the surface area of the small animal to lay eggs or grow. That is, for example, the sheet 1 shown in Figs. 1(a) and 1(b) preferably has L ₁ × L ₂ of 500 cm ² or more, and more preferably 1000 cm ² or more. The upper limit of the apparent surface area is not particularly limited, and is usually set to 80000 cm ² or less in order to satisfy the above-described suitable lengths of L ₁ and L ₂ .

Further, as a condition of the foam unit of the foamed sheet, it is preferred that the foam unit is uniformly distributed. Further, it is preferable that the number of foam units and the pore diameter of the foam unit are controlled to be values of easy adhesion and easy peeling of the sludge. In particular, if the foam unit is excessive or the unit diameter is too large, the mechanical strength of the sheet becomes small, and therefore, Preferably, the number of cells / 25 mm (the number of cells in the range of 25 mm length) is 125 or less / 25 mm, and particularly preferably 100 or less / 25 mm. On the other hand, if the number of the foam cells is too small or the cell diameter is too small, the function as a porous carrier cannot be sufficiently obtained. Therefore, in order to sufficiently exhibit the function of the porous carrier, the number of cells/25 mm is preferably 5 or more and 25 mm. Particularly suitable is more than 25 / 25mm. Further, in order to achieve such a number of foam cells and at the same time to make the sludge adhesion and the peelability good, it is preferred that the foam cell has an average pore diameter of 0.05 to 10 nm, more preferably It is in the range of 0.05 to 1 nm.

Regarding the number of the cells/25 mm, it is possible to use a photograph of a sheet photographed by a scanning electron microscope, and to perform an operation of detecting the number of foam cells intersecting with a straight line of 25 mm in the longitudinal direction at a plurality of places, and calculating the average value of the detection results. The foam cell aperture can be detected as well.

The foam constituting the sheet 1 is not particularly limited. However, since the upward flow caused by the water flow or the aeration is appropriately bent and oscillated due to water swelling, it is preferably a flexible polyurethane foam.

If it is a sheet-like carrier of a foam such as a thin plate or a strip of flexible polyurethane foam having the above-mentioned size, it has sufficient elasticity and is bent in the flow of water in the biological treatment tank (no shape is maintained), although Thin but with sufficient mechanical strength, it is difficult to break. When it is fixed in the biological treatment tank, the force is concentrated on the fixing portion of the sheet 1. Therefore, it is preferable to preliminarily mount the jig at the fixing portion as shown in Fig. 1(b) to improve the mechanical strength. Further, the water is prevented from being blocked by the bending in the biological treatment tank, and uniformly mixed, and the sludge-containing liquid is uniformly distributed in the foam unit of the sheet. In other words, in the present invention, it is preferable to use a swinging carrier for a flexible polyurethane foam sheet having the above-described size as a carrier for holding small animals which is resistant to water damage and which is difficult to break and has elasticity and strength. .

Such a plate-like or elongated sheet 1 can be produced, for example, by slicing a rectangular parallelepiped flexible polyurethane foam into a plate shape or an elongated shape.

The volume of the biological treatment tank to which the oscillating carrier of the present invention is disposed is set to be the apparent surface area of the sheet of the oscillating carrier and the volume of the biological treatment tank (including the biological treatment tank on the return line, including the biological treatment tank) The ratio, that is, the apparent surface area/biotreatment tank volume is 1 to 50 m ^-1 , and is effective for biological treatment suitable for the carrier filling rate of the biological treatment tank load. Here, the apparent surface area of the oscillating carrier is as described above, and refers to the total surface area of the sheet surface of the foam unit which does not contain the foamed plastic sheet, and if the sheet 1 of FIG. 1 is used, the lower surface is used. Formula calculation: (L ₁ × L ₂ × 2) + (L ₁ × d × 2) + (L ₂ × d × 2)

The filling ratio of the oscillating carrier to the biological treatment tank of the present invention is preferably 0.5% or more of the total volume of the biological treatment tank after the biological treatment tank of the micro animal in which the oscillating carrier of the present invention is provided (including the biological treatment tank), and is particularly suitable. It is suitable for effective biological treatment with a carrier filling rate of a suitable biological treatment tank load of 1 to 10%. Here, the carrier filling ratio means the ratio of the apparent volume of the sheet to the total volume of the biological treatment tank. Here, the apparent volume means a volume in which the internal volume of the pores of the foam unit is not considered, and if the sheet 1 of Fig. 1 is used, it is calculated by (L ₁ × L ₂ × d).

In the biological treatment tank, it is necessary to maintain a large number of footholds for micro animals. However, if the carrier filling rate is too large, insufficient mixing in the tank, sludge spoilage, etc., therefore, the filling rate of the added carrier is optimally set. The above range.

Therefore, when only one sheet cannot satisfy the above filling ratio, the oscillating carrier of the present invention is preferably unitized by a plurality of sheets 1 of the mounting jig 2 as shown in Fig. 1(b). Processing in the tank.

Fig. 2 is a perspective view showing a carrier unit in which a sheet 1 is unitized.

The carrier unit 11 shown in Fig. 2(a) is constructed as follows: Although there are four sheets in 2(a), it is not limited to four sheets. The longitudinal direction of each sheet 1 of the sheet 1 is the vertical direction (the depth direction of the biological treatment tank: the vertical direction), and the sheet faces are arranged. In the same plane shape, a plurality of gaps are spaced apart from each other, and they are arranged in the X direction of FIG. 2( a ), and the jig 2 is provided with a fastening tool or the like (for example, an adhesive, a wire, a belt, a fixing screw, etc.). The plurality of matching bodies 3 are fixed to each other as a matching body 3 (five in FIG. 2(a), but not limited to five), and each of the matching bodies 3 is spaced apart from each other by a certain gap. The Y-direction is arranged in parallel, and the jig 2 of each of the array bodies 3 is fixed by a fastening tool (not shown) to be unitized. The carrier unit 12 shown in Fig. 2(b) is obtained by fixing the carrier unit 11 shown in Fig. 2(a) to a frame 4 made of a material such as SUS by a fastening tool or the like (not shown).

In this manner, by arranging a plurality of sheets 1 in parallel and unitizing them, and providing them in the biological treatment tank, they can be provided in the biological treatment tank, so that the oscillating carrier can easily become an optimum filling rate.

The carrier unit 11 shown in Fig. 2(a) can be directly fixed to the inner wall surface in the biological treatment tank by a fastening tool or the like. If the carrier unit 12 shown in Fig. 2(b) is provided, it may be disposed only in the biological treatment tank, or the frame 4 may be partially fixed to the inner wall of the biological treatment tank.

The oscillating carrier is disposed in the biological treatment tank such that the longitudinal direction of the sheet 1 becomes the depth direction of the biological treatment tank, and the short direction of the sheet 1 is irrelevant from the inflow side of the organic drainage (raw water) of the biological treatment tank. The direction of the water flowing out of the outflow side is still in the direction of crossing the water passing direction, whichever is possible.

[Organic drainage biological treatment tank]

The biological treatment tank for organic drainage according to the present invention is characterized in that the swinging carrier of the present invention as described above is preferably provided at the above-described suitable carrier filling ratio.

3 and 4 are perspective views showing an embodiment of the biological treatment tank of the present invention, and the biological treatment tank 21 of Fig. 3 is provided with the above-described array 3 so that the sheet surface of the sheet 1 of the oscillating carrier becomes organic. The direction of the water passing direction (orthogonal) of the drainage (raw water). In Fig. 3, reference numeral 22 is a treatment water discharge pipe. Further, the biological treatment tank 31 of Fig. 4 is provided with a unit for arranging the above-described array 3 so that the sheet surface of the sheet 1 of the oscillating carrier becomes the water-passing direction of the organic drainage (raw water), and in Fig. 4, the symbol The 32-series treated water flows out of the piping. Thus, it is suitable to increase the number of the oscillating carriers according to the width and length of the biological treatment tank, to prevent the short-circuit flow, and to perform the treatment reliably.

When the sheet 1 is not unitized, for example, a plurality of rod-shaped members may be provided in a sheet installation place in the groove, and each of the arrays may be provided by a fastening tool (for example, a binding tape, a metal hook, a piano wire, or the like). The jig 2 of 3 is fixed to a plurality of rod-shaped members, and the sheet 1 is placed in the biological treatment tank.

[Organic drainage biological treatment device and biological treatment method]

The biological treatment apparatus and biological treatment method of the organic drainage according to the present invention are characterized in that biological treatment is carried out using the biological treatment tank of the present invention as described above. Hereinafter, embodiments of the organic wastewater treatment apparatus and biological treatment method of the present invention will be described in detail with reference to Figs. 5 to 8 .

5 to 8 show the biological treatment device for organic drainage of the present invention. A system diagram of the implementation of the method and method.

In Fig. 5 to Fig. 8, 41 is the first biological treatment tank, 42 is the second biological treatment tank, 43 is the membrane separation device, 44 is the oxygen-free tank, 41A, 42A is the diffusing tube, 50 is the micro animal holding carrier, 44A The stirring means is used, and the components having the same functions are denoted by the same reference numerals in FIGS. 5 to 8.

In the embodiment of Fig. 5, raw water (organic drainage) is introduced into the first biological treatment tank 41, and by dispersing bacteria (non-aggregating bacteria), 70% or more, preferably 80% or more, and further preferably More than 85% of the organic components (solubility BOD) are oxidatively decomposed. The pH of the first biological treatment tank 41 is 6 or more, preferably 8 or less. However, when the raw water contains a large amount of oil, or when the electronic industry is drained, the liquid crystal is drained, or the solvent is drained, the pH may be 8 or more.

The mode of circulation into the first biological treatment tank 41 is usually one-pass, and the BOD volume load of the first biological treatment tank 41 is set to 1 kg/m ³ /d or more, for example, 1 to 20 kg/m ³ /d. HRT (raw water retention time) is 24 hours or less, preferably 8 hours or less, for example, 0.5 to 8 hours, whereby the treated water which is dominant by the dispersing bacteria can be obtained, and the HRT can be processed at a high load by shortening the HRT. Drainage with a lower BOD concentration.

In the first biological treatment tank 41, one part of the sludge from the biological treatment tank in the latter stage is returned, or the first biological treatment tank 41 is a multi-layer structure of two or more tanks, or a carrier is added, thereby High-load treatment can be carried out with a BOD volume load of 5 kg/m ³ /d or more.

When the carrier is added to the first biological treatment tank 41, the shape of the carrier may be any shape such as a spherical shape, a granular shape, a hollow cylindrical shape, a linear shape, or a plate shape. The shape can also be any size from about 0.1 to 10 mm in diameter. Further, the material of the carrier may be any material such as a natural material, an inorganic material, or a polymer material, or a gel-like substance may be used. Further, when the filling rate of the carrier added in the first biological treatment tank 41 is high, no scattered bacteria are formed, the bacteria adhere to the carrier, or the linear bacteria proliferate. Therefore, the filling rate of the carrier added to the first biological treatment tank 41 can be 20% or less, preferably 10% or less, without affecting the concentration fluctuation, and it is possible to produce a dispersed bacteria which is easy to prey.

In the first biological treatment tank 41, the dissolved oxygen (DO) concentration may be 1 mg/L or less, preferably 0.5 mg/L or less, to inhibit the proliferation of linear bacteria.

When the dissolved organic matter is completely decomposed in the first biological treatment tank 41, the following biological treatment tank is formed, that is, no lint is formed in the second biological treatment tank 42, and further, the proliferation and nutrition of the microscopic animals are insufficient, and only Sludge with lower compactness predominates. Therefore, the decomposition rate of the organic component in the first biological treatment tank 41 is not 100%, preferably 95% or less, and more preferably 85 to 90%.

The treated water (first biologically treated water) of the first biological treatment tank 41 is circulated to the second biological treatment tank 42 in the subsequent stage, whereby the remaining organic components are oxidatively decomposed, self-decomposed by the dispersed bacteria, and preyed by the tiny animals. The excess sludge is reduced. In the present invention, the swinging carrier of the present invention described above is provided as a micro animal holding carrier 50 in the second biological treatment tank 42 at the above-described appropriate filling rate.

In the second biological treatment tank 42, due to proliferation compared with bacteria The role of tiny animals and the self-decomposition of bacteria are relatively slow, so it is necessary to use operating conditions and processing devices that allow tiny animals and bacteria to stay in the system. Therefore, in the second biological treatment tank 42, it is preferred to use an activated sludge method or a membrane activated sludge method for returning sludge. Further, the second biological treatment tank 42 may have a multilayer structure of two or more grooves. In the case of the membrane type activated sludge method, the membrane separation apparatus may be any one of a tank type (a type of a biological treatment tank, a biological treatment tank/membrane immersion tank, and a tank type), and is a biological treatment. The groove/membrane immersion tanks are respectively provided in a type or a groove shape, and can prevent clogging of the membrane mesh caused by the late dispersion of bacteria at a high load.

In the present invention, by providing the micro animal holding carrier 50 in the second biological treatment tank 42, the micro-animals, in particular, the effective predation of the dispersing bacteria, the solid-liquid separation property of the sludge and the improvement of the treated water quality are improved. The amount of retention in the tank of the predatory micro-animals.

In other words, as described above, in the second biological treatment tank 42, not only the predatory micro-animals which prey on the cells in the dispersed state are propagated, but also the predatory type micro-animals which can prey on the fibrillated sludge can also proliferate. Since the latter is preying on the fiber scrap while swimming, the sludge will be eaten indiscriminately in the case of prioritization, and it becomes a sludge with fine solid-liquid separation and scattered fine fiber chips.

Therefore, in the present invention, the tank sludge is periodically replaced in the second biological treatment tank 42, that is, the SRT (solids retention time) is preferably 60 days or less in order to remove minute animals or feces. More preferably, it is less than 45 days, especially preferably in the range of 10 days or more and 45 days or less. Control is certain. However, when the sludge concentration (MLSS) in the second biological treatment tank 42 is 2000 mg/L or less, SRT>60 days may be used. Here, SRT = (sludge concentration in the tank × aeration tank volume) / (extracted sludge concentration × 1 day extraction amount), sludge concentration in the tank (MLSS) refers to the concentration of suspended sludge, excluding The carrier adheres to the sludge portion.

Further, in order to sufficiently maintain the predatory micro-organisms of the predator-preserved cells in the second biological treatment tank 42, the micro-organism-retaining carrier 50 is provided in the second biological treatment tank 42. That is, the tiny animal of this kind is fixed on the sludge lint and maintained in the system. However, since the sludge is extracted outside the system during the fixed residence time, it is necessary to provide a supply source in the system. At this time, if the carrier is a granular or square fluidized bed, not only cannot be stably maintained at a high concentration due to the shearing force for flow, but also the fluidized bed is completely treated, resulting in contamination. The mud lint is refined, thereby causing the film to occlude. Then, in the present invention, as the carrier provided in the second biological treatment tank 42, the above-described swinging carrier of the present invention is used to stably hold the tiny animals.

In the present invention, when a large amount of organic matter remains in the first biological treatment water to be introduced into the second biological treatment tank 42, the oxidative decomposition is carried out in the treatment tank in the subsequent stage. When oxidative decomposition of organic matter by bacteria occurs in the second biological treatment tank 42 in which a large number of microscopic animals are present, it is known that it is proliferated in a form that is difficult to prey, and is propagated in such a manner as a measure for avoiding predation of small animals. The bacterial group is not preyed by tiny animals, and the decomposition of this part relies solely on self-digestion, resulting in a decrease in the effect of reducing the amount of sludge produced. Therefore, as described above, in the first biological treatment tank 41 Therefore, it is necessary to decompose most of the organic matter, that is, 70% or more, preferably 85 to 90%, and convert it into a bacterial cell. On the other hand, if the organic load of the second layer (including the second layer) is extremely low, the number of bacteria fixed in the tank is reduced, and it is difficult to maintain microscopic animals and bacteria. Therefore, the organic sludge load of the biological treatment tank after the second layer needs to be controlled to be within a suitable range. Here, when the index is set to BOD, the hardly decomposable organic matter that is not completely removed by the first biological treatment tank 41 may be estimated to be low. Therefore, as an index, the solubility TOC sludge load is most effective, and it is preferable to operate so that the solubility TOC sludge load of the second biological treatment tank 42 is 0.005 to 0.05 kg-solubility TOC/kg-MLSS/d. Here, MLSS represents the total of the floating sludge and the carrier-attached sludge.

In Fig. 5, the treated water from the second biological treatment tank 42 is sent to the membrane separation device 43 of the tank type, and the permeated water of the membrane separation device 43 is taken out as the treated water, and the concentrated water is returned to the second biological treatment tank. Upstream of 42, the excess sludge is directly withdrawn from the second biological treatment tank 42. In the case where the membrane separation device 43 is used as the solid-liquid separation means as described above, according to the present invention, the proliferation of the aggregated predatory type micro-animals is suppressed, so that the membrane clogging problem as in the membrane separation apparatus of the prior activated sludge can be alleviated. At the same time, it is possible to prevent the sudden sludge from being dispersed, and the operation management of the membrane separation device can be easily performed.

The membrane separation device 43 which is a groove type is not particularly limited, and an ultrafiltration membrane (hereinafter abbreviated as "UF membrane") membrane separation device, a precision filtration membrane (MF membrane) separation device, or the like can be used.

The difference between the form shown in FIG. 6 and the form shown in FIG. 5 is that the original One part of the water, for example, about 5 to 50%, is directly introduced into the second biological treatment tank 42 without passing through the first biological treatment tank 41, and the others are all configured in the same manner. In this way, by directly introducing one part of the raw water into the second biological treatment tank 42, it is possible to avoid the insufficient load of the second biological treatment tank when the raw water is changed (when the load is lowered). The biological treatment tank is a multi-layered case of three or more layers (including three layers). When the organic matter load after the second layer (including the second layer) is low, for example, as shown in FIG. 6, one part of the organic drainage is bypassed, without passing through the first The biological treatment tank of the layer is directly introduced into the biological treatment tank after the second layer, and the sludge load can be maintained even in the biological treatment tank after the second biological treatment tank.

The form shown in Fig. 7 is obtained by extracting a part of the sludge in the second biological treatment tank 42 holding the micro-animals, returning it to the anaerobic tank 44, and returning it to the micro-animal holding biological treatment tank 42 to suppress the aggregate predation type. The proliferation of the microscopic animals preferentially causes the filtration of the predatory micro-animals to proliferate, and the other configuration is the same as that of the form of Fig. 5 .

In other words, by providing the anaerobic tank 44, the anaerobic tank 44 allows the sludge extracted from the second biological treatment tank 42 to stay for a predetermined period of time, thereby preventing the growth of the biological phase by inhibiting the proliferation of the floating micro-animals. . In this case, the micro-animal holding carrier 50 is provided in the second biological treatment tank 42, and the predatory micro-organisms are kept in a certain amount on the side of the carrier 50, so that the proliferation of the predatory micro-animals is not inhibited. The sludge extracted from the second biological treatment tank 42 and treated in the anaerobic tank 44 is returned to the second biological treatment tank 42.

The morphology shown in Figure 8 is not from the second biological treatment tank 42 to the anaerobic tank. 44 is supplied with sludge, and is branched from the membrane separation device 43 to the second biological treatment tank 42 to transfer the sludge, and a part of the returned sludge is sent to the second biological treatment tank 42, and the remaining portion is returned to the anaerobic tank 44. The other configuration is the same as that of the embodiment of Fig. 7.

By supplying the sludge from the membrane separation device 43 to the anaerobic tank 44 in this manner, the number of pumps to be used for transferring the sludge can be reduced.

In Fig. 7, the amount of sludge extracted from the second biological treatment tank 42 to the anaerobic tank 44 and the residence time of the sludge in the anaerobic tank 44 are appropriately determined depending on the treatment conditions. Usually, preferably, the sludge is extracted. The amount of the tank is 1/30 times/day or more, and the residence time of the sludge in the anaerobic tank 44 is 0.5 hours or more. The sludge supply amount from the membrane separation device 43 to the anaerobic tank 44 and the residence time of the sludge in the anaerobic tank 44 in Fig. 8 are set as the sludge extraction amount in Fig. 7 and the sludge in the anaerobic tank 44. The residence time is the same.

In the present invention, in the anaerobic tank 44, in order to prevent proliferation of small animals, it is necessary to set the ORP to 0 mV or less. For this reason, it is preferred that the aerobic tank 44 is not aerated and only mechanically agitated. Further, in order to promote the reduction of the ORP, one of the first biological treatment water or the raw water may be supplied, and the ORP may be lowered by an acid reaction or a denitrification reaction.

Further, in order to stabilize the ORP of the anaerobic tank 44 (denitrogenation reaction, acid reaction), the carrier can be added to the anaerobic tank 44. If the ORP of the anaerobic tank 44 is low, the activity of the floating micro-animals is promoted, so that the residence time of the second biological treatment tank sludge in the anaerobic tank 44 can be shortened, and the anaerobic tank 44 can be miniaturized. . The added carrier shape is In the case of a fluidized bed, it may have any shape such as a spherical shape, a granular shape, a hollow cylindrical shape, or a linear shape, and the size may be any diameter of about 0.1 to 10 mm. Further, a fixed bed may be used, and in this case, the shape of the carrier may be any shape such as a line shape or a plate shape. Further, the material may be any material such as a natural material, an inorganic material, or a polymer material, and a gel-like substance may also be used.

When the carrier is added to the anaerobic tank 44, the filling rate varies depending on the type of the fluidized bed or the fixed bed or the material, and is preferably 0.5 to 40%.

5 to 8 show an example of an embodiment of the present invention, but the present invention is not limited to the illustrated embodiment. For example, the first biological treatment tank and the second biological treatment tank may be configured as a plurality of layers of two or more layers as described above. Therefore, in the present invention, the biological treatment tank may be three or more layers. Further, the solid-liquid separation of the biological treatment water is not limited to the membrane separation device, and may be a sludge return method using a sedimentation tank, or a sedimentation tank may be used for agglutination and sedimentation separation after one-pass treatment, and further, the solid-liquid separation It can be floating on the separation.

Regardless of the form, according to the present invention, since the oscillating fixed bed carrier of the present invention is provided in the biological treatment tank after the second biological treatment tank, the carrier can be stably maintained as a micro animal holding carrier, and the stain can be prevented. The mud reduction can increase the quality of the treated water, and the biological treatment water after the second biological treatment tank is solid-liquid separated by the membrane separation device to prevent the membrane of the membrane separation device from being blocked, thereby enabling stable high-load treatment. Further, in the case of biologically treated water after agglutination and sedimentation to separate the second biological treatment tank, the amount of the aggregating agent can be reduced.

Example

The present invention will be more specifically described below by way of examples and comparative examples.

[Example 1]

As shown in Fig. 5, the organic drainage of the present invention was treated using an experimental apparatus in which a first biological treatment tank 41 having a capacity of 36 L, a second biological treatment tank 42 having a capacity of 150 L, and a UF membrane separation device 43 were coupled. Raw water containing _{COD Cr: 1000mg / L, BOD} : 640mg / L of artificial substrata.

The processing conditions of each biological treatment tank are as follows.

<First Biological Treatment Tank>

DO: 0.5mg/L

BOD volume load: 3.85kg-BOD/m ³ /d

HRT: 4h

pH: 7.0

<Second biological treatment tank>

DO: 4mg/L

Carrier filling rate: 2%

HRT: 17h

SRT: 30 days

pH: 7.0

Solubility TOC sludge load: 0.01kg-solubility TOC/kg-MLSS/d

Further, as the carrier 50 of the second biological treatment tank 42, a sheet-like flexible polyurethane foam (length 100 cm × width 30 cm × thickness 1 cm / 1 piece, the average pore diameter of the foam unit was 0.1 mm, and the number of units was 50 / One piece of 25mm) is arranged vertically in the groove (the length direction of the carrier is set to the depth direction of the groove). At this time, the apparent surface area (m ² ) of the oscillating carrier/the second biological treatment tank volume (m ³ ) = 4.1 (m ^-1 ), and the filling ratio of the oscillating carrier was 2%.

The upper and lower ends of the carrier 50 are fixed to the frame, and the frame is fixedly fixed to the inner wall surface of the second biological treatment tank.

The overall BOD volume load of the device is 0.73 kg-BOD/m ³ /d, and the overall HRT of the device is 21 h.

As a result, the sludge lint in the second biological treatment tank 42 and the filter-fixed micro-animal (Vorticella nebulifera, Bdelloida) fixed on the carrier 50 are prioritized, and the sludge is prioritized. The conversion rate was 0.1 kg-MLSS/kg-COD _Cr .

The water-soluble solubility COD _Cr concentration of the treated water (permeate water of the membrane separation device 43) was less than 20 mg/L, and was maintained in a good state during the test period.

Further, the membrane separation device 43 has almost no increase in the inter-membrane pressure difference, and a stable flow rate can be maintained even if the reagent cleaning is not performed for one month or more.

[Comparative Example 1]

As the carrier 50 of the second biological treatment tank 42, two ropes are used (two horizontal lines are fixed at intervals of 1 cm on the polyester longitudinal line of 1 m), and the extending direction of the rope is in the depth direction, and the upper end is respectively used by the jig. And lower end The oscillating fixed bed was set in the tank, and the same treatment as in Example 1 was carried out except that the above-described oscillating fixed bed was used.

As a result, sludge microfibres, carriers, and supplemental micro-animals (fishing worms, mites) and aggregate predatory micro-animals were mixed, and the sludge was slightly disintegrated. The sludge conversion rate is 0.12 kg-MLSS/kg-COD _Cr , and the dissolved COD _Cr concentration of the treated water quality is less than 30 mg/L, but the differential pressure of the membrane separation device 43 is larger than that of the first embodiment, and the reagent needs to be performed once a week. Cleaning.

[Reference Example 1]

The sheet-like flexible polyurethane foam used as the carrier 50 of the second biological treatment tank 42 has a size of 100 cm in length × 5 cm in width × 1 cm in thickness (apparent surface area of the widest surface: 500 cm ² ), and a table of the oscillating carrier The apparent surface area (m ² ) / the second biological treatment tank volume (m ³ ) = 0.8 (m ^-1 ), and the rest were treated under the same conditions as in Example 1.

As a result, sludge microfibres, carriers, and supplemental micro-animals (fishing worms, mites) and aggregate predatory micro-animals were mixed, and the sludge was slightly disintegrated. The sludge conversion rate is 0.11 kg-MLSS/kg-COD _Cr , and the dissolved COD _Cr concentration of the treated water quality is less than 30 mg/L, but the differential pressure increase of the membrane separation device 43 is larger than that of the first embodiment, and needs to be performed once every two weeks. Reagent cleaning.

It will be apparent to those skilled in the art that the present invention may be variously modified, and various modifications may be made without departing from the spirit and scope of the invention.

In addition, the present application is based on Japanese Patent Application No. 2011-270270, filed on Dec.

1‧‧‧Sheet

1a‧‧‧Longside

2‧‧‧ fixture

3‧‧‧ 配 配

4‧‧‧Frame

11‧‧‧ Carrier unit

12‧‧‧ Carrier Unit

21‧‧‧ Biological treatment tank

22‧‧‧Processing water outflow piping

31‧‧‧ Biological treatment tank

32‧‧‧Processing water outflow piping

41‧‧‧First biological treatment tank

41A‧‧‧Distribution tube

42‧‧‧Second biological treatment tank

42A‧‧‧ diffuse tube

43‧‧‧ membrane separation device

50‧‧‧Micro animal keeping carrier

Fig. 1 is a perspective view showing an example of an embodiment of the oscillating carrier of the present invention, wherein (a) shows a sheet 1 made of foam as a main body of the oscillating carrier, and (b) shows a state in which the jig 2 is attached to the sheet. 1.

Fig. 2 is a perspective view showing a carrier unit of another embodiment of the swinging carrier of the present invention.

Fig. 3 is a perspective view showing an embodiment of the biological treatment tank of the present invention.

Fig. 4 is a perspective view showing another embodiment of the biological treatment tank of the present invention.

Fig. 5 is a system diagram showing an embodiment of a biological treatment apparatus and method for organic drainage according to the present invention.

Fig. 6 is a system diagram showing another embodiment of the biological treatment apparatus and method for organic drainage according to the present invention.

Fig. 7 is a system diagram showing still another embodiment of the organic wastewater treatment apparatus and method of the present invention.

Fig. 8 is a system diagram showing still another embodiment of the organic wastewater treatment apparatus and method of the present invention.

41‧‧‧First biological treatment tank

41A‧‧‧Distribution tube

42‧‧‧Second biological treatment tank

42A‧‧‧ diffuse tube

43‧‧‧ membrane separation device

50‧‧‧Micro animal keeping carrier

Claims (9)

An oscillating carrier, which is a oscillating carrier for holding small animals in a biological treatment tank, is characterized in that the oscillating carrier comprises a sheet of foamed plastic. The oscillating carrier according to claim 1, wherein the length of the sheet material in the depth direction (long direction) of the biological treatment tank is 100 to 400 cm, and the length in the short direction is 5 to 200 cm. The thickness is 0.5~5cm. The oscillating carrier according to claim 1 or 2, wherein the sheet material has at least two faces having an apparent surface area of 500 cm ² or more. The oscillating carrier according to any one of claims 1 to 3, wherein the number of cells in the range of 25 mm in length of the foam is 5 or more / 25 mm, 125 or less / 25 mm, and the average of the foam cells. The pore size is 0.05~10mm. The oscillating carrier according to any one of claims 1 to 4, wherein the sheet material is composed of a flexible polyurethane foam. An organic wastewater treatment tank for removing organic matter in an organic drainage, characterized in that the oscillating carrier for holding small animals according to any one of claims 1 to 5 is provided. A biological treatment method for organic drainage, which removes organic matter in an organic drainage, and is characterized by biological treatment of an oscillating carrier for holding a micro animal according to any one of claims 1 to 5. The tank flows into the organic drainage. An organic drainage biological treatment device comprises an aerobic biological treatment tank which is formed by two or more layers, and introduces organic drainage into the first biological treatment tank, and biological treatment by bacteria will contain the first biological organism The first biological treatment water of the bacteria in the dispersed state of the treatment tank flows into the biological treatment tank after the second biological treatment tank to perform biological treatment, wherein at least one biological treatment tank after the second biological treatment tank is applied for Biological treatment tank according to item 6 of the patent scope. An organic drainage biological treatment method, introducing organic drainage into a first biological treatment tank which is a two-layer or more multi-layered aerobic biological treatment tank, and biological treatment by bacteria, containing the first biological treatment The first biological treatment water of the bacteria in the dispersed state of the tank is circulated in the biological treatment tank after the second biological treatment tank, and is subjected to biological treatment, wherein the biological treatment tank described in claim 6 is used as the biological treatment tank. At least one biological treatment tank after the second biological treatment tank.