JP4969817B2 - Microbial carrier assembly for water treatment - Google Patents

Description

  The present invention relates to a microbial carrier aggregate for water treatment, and more particularly to a microbial carrier aggregate for water treatment that is released into a water purification tank and separated into a microbial carrier for water treatment.

  Conventionally, a microbial carrier for water treatment using a soft polyurethane foam as a cubic chip is widely known for treating sewage by microorganisms.

  However, since the soft polyurethane foam is difficult to absorb water as it is, there is a problem that the microbial carrier for water treatment is difficult to disperse in the treated water and the sewage treatment efficiency is lowered. Therefore, a treatment for increasing water absorption is performed on the surface of the flexible polyurethane foam. However, if the microbial carrier for water treatment is made small in order to increase the contact efficiency between the microbial carrier for water treatment and the treated water, the surface subjected to the treatment for increasing the water absorption becomes small, the treatment becomes difficult, and it takes time for the treatment work. become.

  In addition, a microbial carrier for water treatment composed of a chip of a flexible polyurethane foam is likely to be scattered around when it is put into a water purification tank, and there is a problem of soiling the surroundings. Furthermore, since the microbial carrier for water treatment made of a flexible polyurethane foam chip is bulky, there is a problem that a packaging volume becomes large and a space is taken for transportation and storage. Therefore, it has been proposed to compress and store a microbial carrier for water treatment made of a soft polyurethane foam chip in a storage bag using a part or all of a water-soluble synthetic resin, and put the bag together into a water purification tank. . According to this, when throwing into the water purification tank, it is possible to prevent the microbial carrier for water treatment from being scattered and to reduce the packing volume. However, since the microbial carrier for water treatment made of flexible polyurethane foam itself is difficult to absorb water, it takes a considerable time for the microbial carrier for water treatment to completely absorb water, and the state of floating on the water surface for a while. There is a problem that it takes time to obtain the original water treatment efficiency.

JP 2004-89803 A

  The present invention has been made in view of the above-mentioned points, and the microbial carrier for water treatment is not scattered when thrown into the water purification tank, the workability is good, and the packaging volume can be further reduced. An object of the present invention is to provide a water treatment microbial carrier assembly in which the water treatment microbial carrier has high water absorption, and the water treatment microbial carrier can be quickly submerged in the treated water.

  In the invention of claim 1, the microbial carriers for water treatment made of a soft synthetic resin foam having an open cell structure are assembled in a compressed state, and the compressed and assembled state is fixed by a binder, and the binder is The present invention relates to a microbial carrier assembly for water treatment, which comprises releasing the compressed and aggregated state by application of water.

  The invention according to claim 2 is the microbial carrier for water treatment according to claim 1, wherein the compressed and aggregated state by the binder is released by moisture when the microbial carrier aggregate for water treatment is put into water. Is characterized in that it can be separated and restored.

  The invention of claim 3 is characterized in that, in claim 1 or 2, the binder is attached in a cell of the microbial carrier for water treatment.

  The invention of claim 4 is characterized in that, in any one of claims 1 to 3, the binder is carboxymethyl cellulose.

The invention of claim 5 is characterized in that, in any one of claims 1 to 3, the binder is a metal salt of an acid having a solid at room temperature, a softening point or a melting point of 80 ° C. or higher .

  A sixth aspect of the present invention is characterized in that, in any one of the first to fifth aspects, the soft synthetic resin foam having the open cell structure is a soft polyurethane foam.

A seventh aspect of the present invention is the soft synthetic resin foam having the open cell structure according to any one of the first to sixth aspects, wherein a cell membrane of the foam is removed. .

  According to the present invention, the microbial carrier assembly for water treatment is assembled in a state where the microbial carrier for water treatment is compressed, and the compression and assembly state are fixed by the binder, and the binder is compressed and assembled by application of water. Since it consists of what cancels | releases a state, a packing volume can be made small compared with packing the microorganism carrier for non-compressed water treatment. Further, when the microbial carrier for water treatment is accommodated in the accommodation bag described in the section of the background art, a gap is easily generated between the microbial carriers for water treatment in the bag, whereas the microbial carrier for water treatment of the present invention is used. Since the aggregate hardly forms a gap between the water treatment microorganism carriers, the packing volume can be reduced as compared with the case where the water treatment microorganism carriers are housed in the housing bag. For this reason, it is possible to transport and store a larger quantity in the same space as in the case of non-compression without taking up space for transportation and storage, thereby reducing transportation costs and storage costs. Further, when the microbial carrier assembly for water treatment is put into the water purification tank, the binder comes into contact with the water in the water purification tank and dissolves, thereby releasing the compressed and aggregated state of the microbial carrier for water treatment, The microorganism carrier for water treatment is separated and restored, and dispersed in the water purification tank. Therefore, when the microbial carrier assembly for water treatment is introduced into the water purification tank, the microbial carrier for water treatment does not scatter and the workability is good.

  Moreover, according to the present invention, the binder is attached to the surface and the cell of the water treatment microorganism carrier made of the soft synthetic resin foam having the open cell structure, and the compression and aggregation state of the water treatment microorganism carrier is fixed. Therefore, the compressed and assembled state can be reliably maintained until the water treatment microorganism carrier is introduced into water. Furthermore, when the carboxymethyl cellulose adheres to the surface and the cell of the microbial carrier for water treatment composed of a soft synthetic resin foam having an open cell structure, and the compressed and assembled state of the microbial carrier for water treatment is fixed, Since carboxymethyl cellulose is water-soluble, the presence of carboxymethyl cellulose can improve the water absorption of the microbial carrier for water treatment. By this water absorption improvement, when the microbial carrier assembly for water treatment is introduced into the water purification tank, the time until the microbial carrier for water treatment sinks below the water surface can be shortened.

  Hereinafter, embodiments of the present invention will be described in detail. FIG. 1 is a diagram showing a microbial carrier assembly for water treatment according to an embodiment of the present invention, and FIG. 2 is a schematic diagram showing decomposition of the microbial carrier assembly for water treatment by charging into a water purification tank.

  A water treatment microorganism carrier assembly 10 shown in FIG. 1 is a collection of a plurality of water treatment microorganism carriers 11 in a compressed state, and the compression and the assembly state are fixed by a binder. 2 (contact with water) to release the compression and aggregation state, as shown in FIG. 2, when it is put into the water purification tank 21 and contacted with water 22, the compression and aggregation state fixation by the binder is released. Thus, the microbial carrier 11 for water treatment is separated and restored.

The microbial carrier 11 for water treatment is made of a soft synthetic resin foam having an open cell structure as a chip of a desired size. The soft synthetic resin foam having the open cell structure is not particularly limited, and examples thereof include a soft polyurethane foam and a polyolefin resin foam. In particular, a flexible polyurethane foam is preferable because it is excellent in wear resistance, inexpensive and easily available. Furthermore, it is preferable that the soft synthetic resin foam having the open cell structure has been removed. In the case of the film removal, the cell membrane is removed by a known blasting method or dissolution method to form a three-dimensional network skeleton, so that water easily penetrates into the inside and the microbial carrier for water treatment is dispersed in water. The time until it can be shortened. In addition, the soft synthetic resin foam having an open cell structure preferably has a bulk density of 20 to 70 kg / m ³ . When the bulk density is lowered, the durability of the water treatment microorganism carrier 11 is lowered. On the other hand, when the bulk density is raised, the cell size (pores) of the water treatment microorganism carrier 11 is reduced and the water absorption is lowered. At the same time, it becomes difficult to compress the microbial carrier 11 for water treatment during the production of the microbial carrier aggregate 10 for water treatment. Although the size of the microorganism carrier 11 for water treatment is set appropriately, it is usually 2 mm to 25 mm. Further, the shape of the water treatment microorganism carrier 11 is an appropriate three-dimensional shape, but is usually a cube in many cases.

  It is preferable that the microbial carrier 11 for water treatment in the microbial carrier assembly 10 for water treatment is compressed to 10 to 70% of the uncompressed volume. If the degree of compression is low, the microbial carrier assembly 10 for water treatment becomes bulky, so that a large amount of space is required for transporting and storing the microbial carrier assembly 10 for water treatment. It becomes difficult to compress the assembly 10 during manufacture.

  Any binder can be used without limitation as long as it adheres by drying and releases the adhesion by application of water (contact with water). Examples of the binder include a water-soluble binder, a metal salt of a low molecular acid, and a nonionic surfactant. As the low-molecular acid metal salt and nonionic surfactant, those having a solid, softening point or melting point of 80 ° C. or higher at room temperature are preferable. Specific examples of the binder include polyvinyl alcohol (PVA), poly N-vinylacetamide (PNVA), methylcellulose (MC), guapac (GP), galactose, mannose, gum rosin disproportionated rosin potassium salt and gum rosin disproportionation. Sodium rosin, synthetic gum arabic, alginate, carrageenan, pectin and vegetable gum, Chinese gum rosin (gum pine incense), gum turpentine oil and their derivatives (polymerized rosin, hydrogenated rosin, disproportionated rosin) ), And esters thereof.

  In particular, carboxymethylcellulose (CMC) that is gelled at room temperature and dried at the time of production of the microbial support assembly 10 for water treatment, or a low molecular acid that is solid at room temperature and has a melting point of 80 ° C. or higher. These metal salts are preferred, such as the above-mentioned gum rosin-based disproportionated rosin potassium salt and gum rosin-based disproportionated rosin sodium salt. Since the carboxymethyl cellulose is biodegraded, if it remains in the cell of the water treatment microorganism carrier 11, the microorganisms that decompose sludge are further activated by decomposing carboxymethyl cellulose, and an increase in sludge treatment capacity can be expected. it can. On the other hand, a metal salt of a low molecular acid that is solid at room temperature, has a softening point, or a melting point of 80 ° C. or higher is selected in consideration of environmental conditions such as handling, storage, and transportation. When the temperature is lower than 80 ° C., the binder may be melted depending on the environmental conditions, and the microbial carrier aggregate for water treatment may collapse. In addition, in the binder that does not have heat resistance and durability at the time of drying, it is altered and becomes insoluble at the time of drying, and when the microbial carrier assembly 10 for water treatment is put into the water purification tank, the binder does not decompose (adhesion release), When the water treatment microbial carrier assembly 10 is transported, the adhesive strength is lowered, and the water treatment microbial carrier 11 is dropped from the water treatment microbial carrier assembly 10. In addition, when corn starch or starch paste is used as a binder, corn starch or starch paste is transformed into gluten by heating during drying and becomes insoluble, so the binder does not dissolve in water, and the water in the microbial carrier assembly 10 for water treatment The processing microorganism carrier 11 was not decomposed or dispersed.

  When carboxymethyl cellulose is used as the binder, the carboxymethyl cellulose has a methylation rate of 0.6 to 1.4, more preferably 0.6 to 0.8 in order to obtain good decomposability with water. In addition, the carboxymethyl cellulose used in the production of the microbial carrier assembly 10 for water treatment preferably has a 2% strength aqueous solution having a viscosity of 10 Pas to 1000 Pas, and more preferably the effect of remaining in the water in the water purification tank. Considering 10 Pas to 100 Pas. Furthermore, the concentration of the aqueous binder solution when producing the microbial carrier assembly 10 for water treatment is preferably 0.5% to 5%. If the concentration is low, the water treatment microbial carrier assembly 10 is liable to collapse during handling. On the other hand, if the concentration is high, the water treatment microbial carrier assembly 10 is difficult to be decomposed by water. ~ 3% is more preferred.

  The method for producing the water treatment microorganism carrier assembly 10 includes a compression step, an immersion step, a compression repetition step, and a drying step.

  In the compression step, a required amount of the water treatment microorganism carrier 11 made of the soft synthetic resin foam chip having the open cell structure is compressed. The compression at that time is preferably compressed to a volume of 10 to 70% of the volume in an uncompressed state. If the compression at that time is large, the pressure applied to perform the compression becomes too large and the compression becomes difficult. On the other hand, if the compression is too small, the aqueous binder solution is converted into a microorganism for water treatment in the subsequent compression repeating step. It becomes difficult to impregnate the inside of the carrier 11. As a specific example of the compression method, as shown in FIG. 3, as shown in FIG. 3, a required amount of the microbial carrier 11 for water treatment is accommodated in a mesh cage 31 that is open at one side (upper side in the figure). A method of compressing the water treatment microorganism carrier 11 in the net cage 31 by inserting the lid body 33 and pushing the lid body 33 into the net cage 31 by a press device or the like will be described. The lid 33 may be a net-like member or a plate-like member having a small hole. In addition, the said mesh | network and a small hole are made into the magnitude | size which the said microorganisms carrier 11 for water treatment does not pass through at the time of compression. In addition, the lid 33 can be fixed in a compressed state by using a toggle clamp 40 as shown in FIG.

  In the dipping step, the mesh basket 31 in a state where the water treatment microorganism carrier 11 is compressed is dipped in the binder aqueous solution. At this time, the microbial carrier 11 for water treatment in the mesh basket 11 is completely positioned below the liquid surface of the aqueous binder solution. Alternatively, the mesh basket 31 may be placed in a container before filling with the binder aqueous solution to perform the compression step, and in this state, the container may be filled with the aqueous binder solution to perform this dipping step. For example, the mesh basket 31 is disposed on the inner bottom surface of the container, the lid 33 is locked to an elevating member of the press device located above, and the lid 33 is moved to a required position in the mesh cage 31 by the press device. The water treatment microorganism carrier 11 may be compressed by pushing to perform the compression step, and then the dipping step may be performed by filling the container with an aqueous binder solution.

  In the compression repetition process, the compression of the water treatment microorganism carrier 11 is temporarily relaxed, and then the compression relaxation and compression are repeated again as many times as necessary, thereby forcing the aqueous binder solution into the water treatment microorganism carrier 11. Impregnate and adhere in the cell. And finally, it is set as the state compressed to 10 to 70% of the volume in an uncompressed state. In the compression relaxation state, the water treatment microorganism carrier 11 is preferably 40 to 80% of the volume in the uncompressed state. If the degree of relaxation is small, the aqueous binder solution is difficult to impregnate the microbial carrier 11 for water treatment. On the other hand, if the degree of relaxation is large, the subsequent amount of compression becomes large. There is a risk that strength will be reduced. In this case, compression and compression relaxation can be performed by moving the lid 33 forward and backward in the net cage 31. As a specific method, the mesh basket 31 is positioned on the bottom surface in the binder aqueous solution container, the lid 33 is locked to the lifting member of the press device disposed above the mesh cage 31, and the lifting member of the press device is secured. The method performed by raising / lowering can be mentioned.

  In the drying step, the water treatment microorganism carrier 11 is taken out from the aqueous binder solution in the compressed state and dried to fix the compressed state and the aggregated state of the water treatment microorganism carrier 11 with the adhesive force of the binder, A microbial carrier assembly 10 for water treatment is obtained. When the mesh basket 31 is used, the position of the lid 33 is fixed by the toggle clamp 40 in the compressed state at the end of the compression repetition process, and the entire mesh cage 31 is taken out from the aqueous binder solution in that state and dried. The microbial carrier assembly 10 for water treatment is formed by heating with an apparatus, and then the microbial carrier assembly 10 for water treatment is taken out from the net cage 31. After the compression repetition step, the aqueous binder solution is discharged from the container, and then the hot air from the heating device is blown onto the mesh basket 31 in the container for drying, and then the microbial carrier assembly 10 for water treatment is sent from the mesh basket 31. You may make it take out. The temperature at the time of drying is a temperature at which moisture can be evaporated by heating, and is usually 70 to 110 ° C.

Example 1
Microorganism carrier for water treatment made of soft polyurethane foam pulverized to length x width x height = 3 x 3 x 3 mm (manufactured by Inoac Corporation, product number; AQ-3, film removal product, bulk density; 50 kg / m ³ ) 0.02 kg was put on a net-like bottom plate 49 arranged at the bottom of a 0.785 liter stainless steel net cage 45 having a cylindrical shape (inner diameter 100 mm, height 100 mm) as shown in FIG. . With the introduction of the water treatment microorganism carrier into the mesh basket 45, the mesh basket 45 was filled with the water treatment microorganism carrier to the upper end. Next, the mesh lid 51 is put on the opening above the mesh basket 45, and the mesh lid 51 is pushed into the mesh basket 45 by the pressing device 53 so that the mesh lid 51 has a height of 20 mm from the mesh bottom plate 49. The microbial carrier for water treatment was compressed between the mesh bottom plate 49 and the mesh lid 51. As a result, the microbial carrier for water treatment is compressed to a volume of 20% with respect to the volume in the non-compressed state and maintained in that state. The mesh of the mesh basket 45, the mesh bottom plate 49, and the mesh lid 51 is 2 mm. The pressing device 53 includes a plate 55 on which an engaged portion 54 that is releasably engaged with an engaging portion 47 projecting from the upper end of the mesh cage 45 is formed, and a plate 55 at the center of the plate 55. A screw member 57 that is screwed through the plate 55 and can be moved up and down by rotation, a lid pressing portion 59 provided at the lower end of the screw member 57, and a rotation member provided at the upper end of the screw member 57 It consists of a gripping part 61. The pressing device 53 engages the engaged portion 54 of the plate 55 with the engaging portion 47 of the mesh cage 45 and attaches it to the mesh cage 45, and in this state, rotates the screw member 57 in one direction and descends. By doing so, the lid pressing part 59 pushes the mesh lid 51 downward to compress the water treatment microorganism carrier between the mesh bottom plate 49 and the mesh lid 51, while the screw member 57 is reversed. By rotating, the lid pressing part 59 is raised, and the compression of the water treatment microorganism carrier can be relaxed or released.

  Next, a 2% concentration carboxymethylcellulose aqueous solution (methylation rate: 0.6 to 0.8, 2% concentration) in which a mesh basket in which the above-mentioned microbial carrier for water treatment is compressed is preliminarily filled in a 3 liter container. Was completely immersed in 100-200 Pas).

  While the mesh cage is immersed in the carboxymethyl cellulose aqueous solution, the screw member 57 of the press device 53 is rotated in the direction opposite to the descending direction so that the microbial carrier for water treatment is 50% of the volume in the uncompressed state. Then, the mesh lid 51 is raised to a position where the distance from the mesh bottom plate 49 is 50 mm, and then the screw member 57 is rotated again in the direction of lowering so that the water treatment microorganism carrier is in an uncompressed state. The mesh lid 51 was lowered from the mesh bottom plate 49 to a position of 20 mm so as to be 20% of the volume. In this state, the net basket 45 is taken out from the carboxymethyl cellulose aqueous solution, stored in a drying cabinet, dried by heating at 90 ° C. for 24 hours, and then the compressed water and the assembled state of the water treatment microorganism carrier are fixed. The microbial carrier assembly for treatment was taken out from the mesh basket 45.

The water treatment microorganism carrier assembly of Example 1 obtained in this way had a diameter of 100 mm, a height of 20 mm, a volume of 157 cm ³ , and a packing volume of 0.2 liters. When this water treatment microbial carrier assembly was put into a water tank, it was completely separated into a water treatment microbial carrier in 20 to 45 minutes, and all the separated water treatment microbial carriers were under the surface of the water.

Example 2
Instead of the carboxymethylcellulose aqueous solution having a concentration of 2% in Example 1, a 3% aqueous solution of gum rosin-based disproportionated rosin potassium salt was used, and a mesh basket in which the microbial carrier for water treatment was compressed was placed in a container having a volume of 3 liters. Were completely immersed in a 3% aqueous solution of the above-mentioned gum rosin-based disproportionated rosin potassium salt. Further, in the state in which the mesh cage is immersed in a 3% aqueous solution of gum rosin-based disproportionated rosin potassium salt, the screw member 57 of the pressing device 53 is rotated in the direction opposite to that when the descent is performed, thereby The mesh lid 51 is raised to a position where the distance from the mesh bottom plate 49 is 50 mm so that the carrier is 50% of the volume in an uncompressed state, and then the screw member 57 is rotated again in the direction of lowering. The reticulated lid 51 was lowered from the reticulated bottom plate 49 to a position of 20 mm so that the water treatment microorganism carrier was 20% of the uncompressed volume. In this state, the net basket 45 was taken out from the 3% aqueous solution of the gum rosin-based disproportionated rosin potassium salt, stored in a drying cabinet, and dried by heating at 100 ° C. for 20 minutes. Thereafter, the water treatment microorganism carrier aggregate of Example 2 in which the compressed state and the aggregation state of the water treatment microorganism carrier were fixed was taken out of the net cage 45. The water treatment microorganism carrier assembly of Example 2 obtained in this way had a diameter of 100 mm, a height of 20 mm, a volume of 157 cm ³ , and a packing volume of 0.2 liters. When this water treatment microbial carrier assembly was put into a water tank, it was completely separated into a water treatment microbial carrier in 20 to 45 minutes, and all the separated water treatment microbial carriers were under the surface of the water.

  In addition, the same amount of the microbial carrier for water treatment as in the above example was compared with the conventional packaging in which it was wrapped in a resin sheet and packed in a cardboard box without performing compression and assembly state fixation with a binder. The microbial carrier aggregate for water treatment has a conventional packing volume of 40%.

  Further, when a microbial carrier for water treatment that was not compressed and aggregated by the binder was put into a water tank, it took 6 hours and 45 minutes to submerge under the surface of the water. From this, it can be seen that in this example, the time required to be submerged under the water surface can be shortened to 5 to 12% compared to the conventional case.

It is a figure which shows the microorganisms carrier assembly for water treatment which concerns on one Embodiment of this invention. It is a schematic diagram which shows decomposition | disassembly of the microorganisms carrier assembly for water treatment by throwing into a water purification tank. It is the schematic which shows the example at the time of compression of the microorganisms carrier for water treatment. It is a figure which shows the example of the toggle clamp which fixes the cover body to a net cage | basket by making the microorganisms for water treatment in a net cage | basket compressed. It is the schematic of the net cage | basket and press apparatus etc. which were used in the Example.

Explanation of symbols

10 Microorganism carrier assembly for water treatment 11 Microbe carrier for water treatment 31, 45 Net basket 33, 51 Lid

Claims (7)

  Microorganism carriers for water treatment composed of a soft synthetic resin foam having an open cell structure are assembled in a compressed state, the compressed and assembled state is fixed by a binder, and the binder is compressed and formed by application of water. A microbial carrier assembly for water treatment, characterized in that it comprises a substance that releases the aggregated state.   The water treatment microbial carrier aggregate is released into water, so that the compressed and aggregated state by the binder is released with moisture, and the water treatment microbial carrier can be separated and restored. The microbial carrier assembly for water treatment according to claim 1.   The microbial carrier assembly for water treatment according to claim 1 or 2, wherein the binder is attached in a cell of the microbial carrier for water treatment.   The microbial carrier assembly for water treatment according to any one of claims 1 to 3, wherein the binder is carboxymethylcellulose. The microbial carrier assembly for water treatment according to any one of claims 1 to 3, wherein the binder is a solid at normal temperature, a metal salt of an acid having a softening point or a melting point of 80 ° C or higher .   The microbial carrier assembly for water treatment according to any one of claims 1 to 5, wherein the soft synthetic resin foam having the open cell structure is a soft polyurethane foam. The microbial carrier assembly for water treatment according to any one of claims 1 to 6, wherein the soft synthetic resin foam having the open cell structure is obtained by removing the cell membrane of the foam. body.

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