JP6290274B2 - Bioreactor element and wastewater treatment method using bioreactor element - Google Patents

Description

  The present invention relates to a bioreactor element and a method for treating waste water using the bioreactor element. Specifically, it is a fixed-bed type bioreactor element that uses a carrier fixed inside the wastewater treatment tank, and it can save and save costs while efficiently adsorbing and immobilizing microorganisms. The present invention relates to a high bioreactor element and a wastewater treatment method using the bioreactor element.

  As a method for treating sewage, industrial wastewater, etc. (hereinafter collectively referred to as “drainage”), many biological treatment methods have been proposed in which a microorganism is filled in a wastewater treatment tank and a reaction by the microorganism is used. Yes. As a biological treatment method for this type of wastewater, mainly the activated sludge method is widely known.

  The activated sludge method is a method of purifying wastewater by microorganisms contained in activated sludge, and by activating various aerobic microorganisms by aeration and repeating the process of decomposing organic matter in the wastewater into carbon dioxide and water, This is a method for purifying waste water. In such an activated sludge method, since the decomposition reaction is slow, it is necessary to increase the scale of the equipment, and there is a problem that the installation area is large and high operating costs are required.

  In recent years, a method has been used in which a carrier capable of immobilizing microorganisms is used to increase the concentration of microorganisms in the wastewater treatment tank and increase the reaction rate of wastewater purification. Such wastewater treatment methods using a carrier include a fluidized bed method in which a carrier is introduced into a wastewater treatment tank and fluidized, and a fixed bed method in which the carrier is installed at a fixed position in the wastewater treatment tank. .

  The fluidized bed method is a method in which a microorganism concentration is increased by supporting microorganisms on a carrier that can flow in a wastewater treatment tank, and an excellent treatment capacity can be obtained. However, in order to prevent the carrier from flowing out from the waste water treatment tank, a device for separating the carrier from the treated water is necessary, and there is also a problem of clogging of the separation device, so that the maintenance cost such as maintenance and maintenance is low. There is a problem of becoming higher.

  In contrast, in the fixed bed method, microorganisms can be adsorbed and fixed at a high density on a carrier fixed at a fixed position in the wastewater treatment tank to increase the wastewater treatment capacity. Since no carrier separation is required, the entire apparatus can be made compact and easy to maintain, and there is an advantage that the running cost can be reduced.

  On the other hand, the fixed bed method has a problem that, for example, it takes a long time to adsorb and immobilize microorganisms on the surface of a hollow fiber membrane as a carrier. In order to solve such a problem, the present inventor in Patent Document 1 uses a sludge substance containing nitrifying bacteria and denitrifying bacteria to increase the ionic strength thereof, so that the surface of the hollow fiber that is the carrier has nitrifying bacteria. And a bioreactor element capable of effectively adsorbing and fixing denitrifying bacteria in a short time.

  Specifically, as shown in FIG. 6, by increasing the ionic strength around the hollow fiber 102 as a carrier to 0.2 to 0.3, the surface of the microorganism is directly and irreversibly applied to the hollow fiber 102 surface. Adsorption and immobilization can be promoted. Here, when adsorbing and immobilizing microorganisms on the surface of the hollow fiber 102, first, the microorganisms in the first layer 103 that are in direct contact with the surface of the hollow fiber 102 are immobilized in a thin film shape, and the microorganisms on the first layer 103 are sufficient. If it is immobilized, a strong thin film is easily formed on the second layer 104 and subsequent layers immobilized on the microorganism of the first layer 103 based on the microorganism of the first layer 103.

  According to Patent Document 1, conventionally, the adsorption and immobilization of the first layer 103 on the surface of the hollow fiber 102 of microorganisms required a period of about 2 to 3 weeks, but by significantly increasing the ionic strength. Thus, the adsorption and immobilization of the microorganisms on the surface of the hollow fiber 102 is achieved in about 48 hours at room temperature.

JP 2010-284617 A

  However, as in the technique disclosed in Patent Document 1, the hollow fiber used as a carrier is originally used for removing impurities contained in water in a household water purifier and the like, and is used as a wastewater treatment. Since there are few examples, there is a problem that raw material costs are high.

  Further, in order to promote the adsorption and fixation of microorganisms in the hollow fiber, a suspension containing an organic substance and an inorganic salt composed of at least one of alcohols, sugars, and organic acid salts is generated, and the ions A lot of man-hours are required for preparation at the stage before wastewater treatment, such as the need to adjust the strength.

  Furthermore, the hollow fiber is compact, but its mechanical strength is small. Therefore, the hollow fiber is easily broken during the operation or maintenance of the wastewater treatment apparatus, and it is necessary to replace it periodically.

  As described above, although the bioreactor element disclosed in Patent Document 1 can adsorb and immobilize microorganisms in a short period of time, it requires a lot of man-hours for raw material costs, preparation steps, etc., and is low in practical use. It was a thing.

  The present invention was devised in view of the above points, and is a fixed-bed type bioreactor element that is used by immobilizing a carrier inside a wastewater treatment tank, and is a space-saving and low-cost microorganism. An object of the present invention is to provide a bioreactor element having a high water treatment capacity capable of efficiently adsorbing and immobilizing water, and a wastewater treatment method using the bioreactor element.

  In order to achieve the above object, the bioreactor element of the present invention includes a first mesh body arranged so that a filamentous material made of a porous material forms a mesh, and a filamentous material made of a fiber-based material is a mesh. And a second mesh body that is disposed adjacent to the front and back surfaces of the first mesh body so as to sandwich the first mesh body.

  Here, since the first network is made of a porous material, the surface area can be increased, so that a large amount of microorganisms can be adsorbed and immobilized quickly, and wastewater treatment can also be performed quickly. It can be carried out.

  Further, since the first mesh body is configured to form a mesh, for example, when the bioreactor element is installed in a wastewater treatment tank filled with sewage containing a large amount of microorganisms, the mesh of the mesh is formed. Convection of sewage can be promoted through the opening. Therefore, the sewage is not stagnated and the microorganisms can be adsorbed and immobilized uniformly in the entire bioreactor element.

  In addition, since the second network is made of a fiber-based material, it has high hydrophilicity, so that microorganisms can be adsorbed and immobilized quickly, and wastewater treatment can also be performed quickly.

  Further, since the second mesh body is configured to form a mesh, as described above, when the bioreactor element is installed in a wastewater treatment tank filled with sewage containing microorganisms, the mesh of the mesh is formed. Since sewage convects through the opening, microorganisms can be adsorbed and immobilized uniformly in the entire bioreactor element.

  In addition, since the second mesh body is arranged so as to be adjacent to the front and back surfaces of the first mesh body so as to sandwich the first mesh body, the microorganisms contained in the sewage are firstly first. Is adsorbed and immobilized on a second mesh body adjacent to the front surface (back surface) of the mesh body. At this time, since the sewage is convected in the waste water treatment tank by a pump, blower, stirrer, etc., some of the microorganisms adsorbed and immobilized on the second mesh body are peeled off, but the microorganisms that have been peeled off are the inner layer. It is adsorbed and immobilized on the first mesh body.

  Furthermore, even if a part of the microorganisms adsorbed and immobilized on the first net is peeled off, it is adsorbed and immobilized on the second net adjacent to the back surface (front surface) of the first net. As described above, since the microorganisms can be adsorbed and immobilized on the bioreactor element in at least three stages, a large amount of microorganisms can be adsorbed and immobilized quickly, and the wastewater treatment can also be performed quickly. .

  In addition, the first net-like body made of the porous material is laminated so as to be sandwiched between the second net-like body made of the fiber-based material, so that the porous material has lower hydrophilicity than the fiber-based material. The material can be protected by the second network, which is a highly hydrophilic fibrous material, and microorganisms can be adsorbed and immobilized quickly, and wastewater treatment can also be performed quickly.

  In addition, when the second mesh body covers the entire front and back surfaces of the first network body, the second network body having high hydrophilicity covers the entire first network body. The microorganisms can be rapidly adsorbed and immobilized, and wastewater treatment can also be performed quickly.

  Moreover, when it has the periphery junction part which joins the outer periphery of a 1st mesh body, and the part which a 2nd mesh body overlaps, a 1st mesh body and a 2nd mesh body are integrated in a lamination | stacking state. Therefore, it can be easily installed in the wastewater treatment tank. Furthermore, for example, the microorganisms that have been peeled off from the first mesh that is the inner layer can be retained between the first mesh and the second mesh.

  A first direction joint that joins the second mesh and the first mesh in the stacking direction at a predetermined interval in the first direction along the outer peripheral portion of the second mesh; and A second-direction joint that joins the first mesh and the second mesh in the stacking direction at a predetermined interval in a second direction substantially orthogonal to the first direction along the outer peripheral portion of the mesh Since the first and second nets can be firmly bonded, deterioration due to repeated use can be prevented.

  Furthermore, since the small compartments separated by the first direction joint and the second direction joint are formed, the microorganisms that have come off from the first mesh located in the inner layer can be retained in each of the small compartments. It becomes possible.

  In addition, when the porous material contains bamboo charcoal in the resin-based material, since the bamboo charcoal is relatively inexpensive to manufacture and has good compatibility with the resin-based material, the first net can be easily manufactured. it can. In addition, bamboo charcoal has a large specific surface area among porous materials and has a high adsorption capacity, so that a large amount of microorganisms can be adsorbed and immobilized quickly, and wastewater treatment can also be performed quickly.

  Moreover, when bamboo charcoal contains 3 to 5 weight% with respect to 100 weight% of 1st net bodies, the intensity | strength and adsorption | suction capability of a 1st net body can be made compatible. That is, when bamboo charcoal is less than 3% by weight with respect to 100% by weight of the first network, the amount of microorganisms adsorbed and immobilized is small, and the water treatment capacity of the bioreactor element is inferior, whereas bamboo charcoal is the first If it exceeds 5% by weight with respect to 100% by weight of the mesh body, the strength of the first mesh body will be weakened and will be easily damaged during use.

  In addition, when polyethylene is used as the resin material for the first mesh body, the manufacturing cost is low, mass production is possible, and it is excellent in water resistance and chemical resistance. Deterioration due to use can be prevented.

  In addition, when the second network is made of polyester, which is a fiber material, the production cost is low, mass production is possible, and because of the high hydrophilicity, microorganisms can be adsorbed and immobilized quickly. be able to. Furthermore, since it is excellent in water resistance and chemical resistance, deterioration due to repeated use in the waste water treatment tank can be prevented.

  In order to achieve the above object, a bioreactor element of the present invention comprises a porous material and a mesh-like body in which a filamentous material made of a fibrous material forms a mesh and covers the entire porous material. .

  Here, since the bioreactor element has a porous material, the surface area can be increased, so that a large amount of microorganisms can be adsorbed and immobilized quickly, and wastewater treatment can also be performed quickly.

  Moreover, since the mesh body is made of a fiber-based material, the hydrophilicity is high, so that microorganisms can be adsorbed and immobilized quickly, and wastewater treatment can also be performed quickly.

  Moreover, when the bioreactor element is installed in a wastewater treatment tank filled with sewage containing microorganisms, the sewage convects through the mesh openings because the mesh body is configured to form a mesh. Therefore, it is possible to uniformly adsorb and immobilize microorganisms in the entire bioreactor element.

  Moreover, when the net-like body covers the entire porous material, the microorganisms contained in the sewage are first adsorbed and immobilized on the net-like body covering the porous material. At this time, since the sewage is convected in the wastewater treatment tank by a pump, blower, stirrer, etc., some of the microorganisms adsorbed and immobilized on the mesh are peeled off, but the microorganisms that have fallen off are inside the mesh. Adsorbed and immobilized on a porous material.

  Furthermore, even if a part of the microorganisms adsorbed and immobilized on the porous material is peeled off, the entire porous material is covered with the network, so that a part of the microorganisms that have fallen off the porous material Adsorbed and fixed in a net state. As described above, since the microorganisms can be adsorbed and immobilized on the bioreactor element in at least two stages, a large amount of microorganisms can be adsorbed and immobilized quickly, and wastewater treatment can also be performed quickly. .

  In order to achieve the above object, the wastewater treatment method using the bioreactor element of the present invention comprises a first mesh body arranged such that a filamentous body made of a porous material forms a mesh, and a fiber system. A biomaterial composed of a second mesh that is formed by forming a mesh of a material, and is adjacent to the front and back surfaces of the first mesh so as to sandwich the first mesh. A step of adsorbing and immobilizing microorganisms on the reactor element; and a step of disposing the bioreactor element adsorbed and immobilized by microorganisms in a wastewater treatment tank and performing a predetermined wastewater treatment.

  Here, by having the step of adsorbing and immobilizing microorganisms on the bioreactor element in which the second network made of a fiber-based material is laminated and disposed adjacent to the front and back surfaces of the first network made of a porous material. In addition, it is possible to rapidly adsorb and immobilize a large amount of microorganisms required for wastewater biological treatment, and also to quickly perform wastewater treatment.

  In addition, by providing a bioreactor element on which microorganisms are adsorbed and immobilized inside a wastewater treatment tank and performing a predetermined wastewater treatment, wastewater can be purified using a reaction by microorganisms.

  The bioreactor element and the wastewater treatment method using the bioreactor element according to the present invention are capable of efficiently adsorbing and immobilizing microorganisms in a short time while being space-saving and low in cost, and have a high water treatment capacity. It has become.

It is a perspective view which shows the structure of the bioreactor element which concerns on embodiment of this invention. It is a top view of the bioreactor element concerning the embodiment of the present invention. In FIG. 2, it is sectional drawing seen along line AA. It is a figure which shows the state which installed the bioreactor element which concerns on embodiment of this invention in the waste water treatment tank. It is a figure which shows the processing method of waste_water | drain using the bioreactor element which concerns on embodiment of this invention. It is a figure which shows a prior art.

  Hereinafter, embodiments of the present invention relating to a bioreactor element and a method for treating wastewater using the bioreactor element will be described with reference to the drawings for understanding of the present invention.

  First, an overall configuration of a bioreactor element 1 according to an embodiment to which the present invention is applied will be described with reference to FIG. The bioreactor element 1 is formed by weaving a mesh having a mesh size of about 1 to 3 mm, and arranging the inner mesh 2 (“first mesh” in the claims) as a flat plate, and the inner mesh. Adjacent to the front and back surfaces of the body 2, the outer mesh bodies 3, 3 having the same shape are knitted and formed in a mesh shape with openings of about 0.5 mm to 1 mm, and are laminated so as to sandwich the inner mesh body 2. ("Second reticulate body" in the claims).

  Here, the outer mesh bodies 3 and 3 do not necessarily have the same shape in the upper layer and the lower layer with the inner mesh body 2 interposed therebetween. The outer nets 3 and 3 may have different sizes and shapes as long as the entire inner net 2 can be covered.

  In addition, it is not always necessary that two outer nets 3 and 3 are disposed on the upper layer and the lower layer with the inner net 2 interposed therebetween. For example, a configuration in which one outer net 3 is folded at an intermediate portion and the inner net is sandwiched may be employed.

  Further, the inner mesh body 2 does not necessarily have to be a single sheet. For example, you may laminate | stack on 2 sheets or more. However, as the number of stacked layers increases, the convection of the fluid in the waste water treatment tank is hindered, and it may take time for the microorganisms to adsorb and immobilize the bioreactor element 1, or the internal clogging may occur. Therefore, it is preferable to appropriately change the number of stacked layers in consideration of the size of the waste water treatment tank.

  Further, the openings of the outer mesh body 3 and the inner mesh body 2 are not necessarily limited to sizes of about 0.5 mm to 1 mm and about 1 to 3 mm, respectively, and can be appropriately changed. is there. However, if the size of the opening is too large, the microorganisms will not get entangled with the mesh part, and if the size of the opening is too small, the convection of the fluid in the waste water treatment tank 7 will be hindered. However, it cannot efficiently adsorb and immobilize microorganisms.

  Moreover, the inner net body 3 does not necessarily have to be knitted into a mesh shape. For example, what processed porous materials, such as Shirasu (volcanic ejecta), may be used.

  The inner mesh body 2 is formed in a flat plate shape by knitting a filamentous material formed by kneading, for example, bamboo charcoal as a porous material into polyethylene as a resin material so as to form a mesh. At this time, the blending ratio of bamboo charcoal is 1 to 10% by weight, preferably 3 to 5% by weight with respect to 100% by weight of the inner mesh body.

  Here, it is not always necessary to use polyethylene as the resin material. For example, it can be appropriately selected from general-purpose plastic materials such as polypropylene, polyvinyl chloride, polyurethane, polyvinylidene fluoride, and polysulfone. However, as a result of repeated experiments by the inventor, when polyethylene was used, microorganisms could be adsorbed and immobilized most efficiently.

  Moreover, it is not always necessary to use bamboo charcoal as the porous material. For example, it can be appropriately selected from substances having many pores such as activated carbon and zeolite. However, as a result of repeated experiments by the inventor, bamboo charcoal has the lowest production cost, has a large specific surface area, and was able to efficiently adsorb and immobilize microorganisms.

  In addition, the blending ratio of bamboo charcoal is not necessarily 1 to 10% by weight, preferably 3 to 5% by weight with respect to 100% by weight of the inner net body 2. However, when the blending ratio of bamboo charcoal is less than 1% by weight, the amount of microorganisms adsorbed and immobilized on the inner mesh body 2 is small and the water treatment capacity of the bioreactor element 1 is poor, while the blending ratio of bamboo charcoal is 10% by weight. If it exceeds, the strength of the outer net-like body 3 becomes weak, and it tends to be damaged during use.

  The outer net-like body 3 is formed in a flat plate shape by weaving a thread-like body made of polyester as a fiber material as a raw material so as to form a mesh.

  Here, it is not always necessary to use polyester as the fiber material. For example, it can be appropriately selected from fiber materials such as nylon, vinylon, and polypropylene. However, since polyester has a higher affinity with microorganisms than other fiber materials, microorganisms can be adsorbed and immobilized most efficiently.

  FIG. 2 is a plan view of the bioreactor element 1 according to the embodiment of the present invention. The bioreactor element 1 has, for example, a rectangular size of 100 cm in width and 150 cm in length, and the entire circumference extends along the part where the outer periphery of the inner mesh 2 and the outer mesh 3 overlap. The outer mesh body 3 and the inner mesh body 2 are integrated by sewing with a thread so as to penetrate the reactor element 1 in the thickness direction. A portion sewn in the circumferential direction is referred to as a peripheral joint 4.

  Here, the bioreactor element 1 does not necessarily have to be rectangular. For example, a square shape, a rhombus shape, a round shape, or the like can be appropriately selected according to the size and shape of the wastewater treatment tank in which the bioreactor element 1 is installed.

  Further, it is not always necessary to sew the entire periphery of the bioreactor element 1 along the outer edge of the outer mesh body 3. For example, when the outer net 3 is sandwiched between the inner net 2 and the outer net 3 is folded at an intermediate portion, and the inner net 2 is sandwiched between the outer nets 3, What is necessary is just to sew a side.

  Further, it is not always necessary to sew the outer mesh body 3 and the inner mesh body 2 with a thread as means for integrating the outer mesh body 3 and the inner mesh body 2. For example, it can be bonded and integrated by other known bonding means such as an adhesive.

  The bioreactor element 1 penetrates the entire bioreactor element 1 in the thickness direction with a thread in the longitudinal direction which is the first direction, that is, in the longitudinal direction in FIG. So that it is sewn. The portion sewn in the vertical direction is referred to as a first direction joint portion 5.

  In addition, the second direction substantially perpendicular to the first direction, that is, the lateral direction in FIG. 2, is sewn with a thread so as to penetrate the entire bioreactor element 1 in the thickness direction. ing. The portion sewn in the lateral direction is referred to as a second direction joint portion 6. As described above, the bioreactor element 1 is sewn so as to be integrated with the inner mesh body 2 in a grid pattern along the outer peripheral portion of the outer mesh body 3 by the thread.

  FIG. 3 is a cross-sectional view of the bioreactor element 1 shown in FIG. 2 taken along line AA. As shown in FIG. 3, the bioreactor element 1 has the inner mesh 2 sandwiched between the outer mesh 3 adjacent to the front and back surfaces of the inner mesh 2, the first direction joint 5, and the second direction. A small compartment 15 is formed by sewing together in a grid pattern so that the outer mesh body 3 and the inner mesh body 2 are integrated by the joint portion 6.

  Here, it is not always necessary to have the first direction joint portion 5 and the second direction joint portion 6. For example, the outer mesh body 3 and the inner mesh body 2 may be integrated only by the peripheral joint 4. However, it is sewn in a grid pattern by the first direction joint portion 5 and the second direction joint portion 6 to form a small compartment 15 so as to be adsorbed and fixed to the outer mesh body 3 and the inner mesh body 2. Even if the microorganisms are peeled off due to some influence such as external force, the microorganisms that have been peeled off can be received in the small compartment 15, and therefore, the first direction joint 5 and the second direction joint 6 are provided. It is preferable.

  In addition, the first direction joint portion 5 does not necessarily need to be sewn at four positions where the lateral width of the bioreactor element 1 is equally divided into five. For example, you may provide a 1st direction junction part so that it may become 4 divisions or less, or 6 divisions or more. Furthermore, the separation distance of each 1st direction junction part 5 does not need to be equal, and may be comprised unevenly.

  In addition, the second direction joint portion 6 does not necessarily need to be sewn at five positions where the longitudinal width of the bioreactor element 1 is equally divided into six. For example, you may provide a 2nd direction junction part so that it may become 5 divisions or less, or 7 divisions or more. Furthermore, the separation distance of each 2nd direction junction part does not need to be equal, and may be comprised unevenly.

  In addition, the angle at which the first direction joint 5 and the second direction joint 6 intersect does not necessarily need to be a substantially right angle. The 1st direction junction part 5 and the 2nd direction junction part 6 may cross | intersect so that it may become an acute angle (obtuse angle).

  However, when each 1st direction junction part 5 and each 2nd direction junction part 6 are located in equal separation distance, respectively, and the 1st direction junction part 5 and the 2nd direction junction part 6 cross | intersect so that it may cross substantially orthogonally In addition, since the surface area and volume of each small compartment 15 become constant, and the bioreactor element 1 as a whole can adsorb and immobilize microorganisms uniformly, stable treatment of waste water becomes possible.

  FIG. 4 is a view showing a state in which the bioreactor element 1 is installed in the waste water treatment tank 7. The bioreactor element 1 is attached to the support frame 8 and installed in the waste water treatment tank 7. As an installation form in the waste water treatment tank 7, for example, as shown in FIG. 4A, inflow of waste water from the waste water treatment tank 7 with one side of the flat bioreactor element 1 attached to the support frame 8. It is suspended from the waste water treatment tank 7 at two positions on the side and the outflow side of the treated water. At this time, the planar portion of the bioreactor element 1 is installed so as to face in the direction in which the wastewater flows.

  Here, it is not always necessary that the flat portion of the bioreactor element 1 is disposed so as to face the direction in which the wastewater flows. For example, the planar portion of the bioreactor element 1 may be attached so as to be parallel to the inflow direction of the waste water or at an arbitrary angle. Further, as shown in FIG. 4 (b), the support frame 8 may be used in common, and a plurality of bioreactor elements 1 may be attached in the circumferential direction.

  In addition, the bioreactor element 1 does not necessarily have to be installed at two locations on the waste water inflow side and the treated water outflow side, respectively. For example, you may install in any one place or three or more places. However, when it is installed in one place, the total area for adsorbing and immobilizing microorganisms becomes small, and the wastewater treatment capacity becomes relatively low. Further, when installed at three or more locations, there is a possibility that the convection of the waste water in the waste water treatment tank 7 may be hindered, and the microorganisms may not be efficiently adsorbed and immobilized on the bioreactor element 1. . Therefore, it is necessary to select appropriately according to the volume of the waste water treatment tank 7.

  Next, the whole structure of the waste water treatment apparatus 9 using the bioreactor element 1 to which the present invention is applied will be described with reference to FIG.

  As a basic configuration of the waste water treatment device 9, a denitrification tank 10 as a waste water treatment tank and a nitrification tank 11 are connected one by one, and a precipitation tank 12 is further connected. The denitrification tank 10 and the nitrification tank 11 are preliminarily filled with sewage containing sludge. The bioreactor element 1 is installed in the denitrification tank 10 and the nitrification tank 11 filled with the sewage, and is immersed in sewage adjusted to a temperature of about 30 ° C. for a predetermined period of time, whereby the outer network 3 of the bioreactor element 1. Innumerable microorganisms including denitrifying bacteria and nitrifying bacteria are adsorbed and immobilized on the inner net 2.

  Here, the temperature of the sewage in which the bioreactor element 1 is immersed is not necessarily adjusted to around 30 ° C. For example, it may be set to a temperature higher than 30 ° C or a temperature lower than 30 ° C. However, as a result of repeated experiments by the inventors, when the temperature of sewage was set to around 30 ° C., adsorption and immobilization of a large amount of microorganisms on the bioreactor element 1 could be completed in a short period of time.

  Further, the denitrification tank 10 and the nitrification tank 11 as the waste water treatment tank do not necessarily need to be connected one by one. For example, two units or more may be connected, or only one of the denitrification tank 10 and the nitrification tank 11 may be provided, and can be appropriately changed according to the wastewater to be treated.

  Further, it is not always necessary to immerse the bioreactor element 1 in the denitrification tank 10 and the nitrification tank 11 filled with sewage. For example, the bioreactor element 1 may be installed in the denitrification tank 10 and the nitrification tank 11 in advance, and then the sewage may be poured into the denitrification tank 10 and the nitrification tank 11.

  After confirming that the microorganisms are adsorbed and immobilized on the bioreactor element 1 installed in the denitrification tank 10 and the nitrification tank 11, first, wastewater to be treated is supplied to the denitrification tank 10. A part of the treated water treated in the nitrification tank 11 is supplied to the denitrification tank 10 as a circulating liquid.

  In the denitrification tank 10, denitrifying bacteria among microorganisms adsorbed and immobilized on the bioreactor element 1 by nitrous acid, nitric acid, and organic substances as hydrogen donors contained in the wastewater under anaerobic conditions in which oxygen is removed. Will increase proliferation. In addition, when the organic matter contained in the waste water is insufficient, organic matter such as methanol is supplied from the outside.

  Further, the denitrification tank 10 is provided with a stirrer 13, and the treated water that has been treated in the nitrification tank 11 and supplied as a circulating liquid is mixed therewith. Here, since the circulating liquid from the nitrification tank 11 contains nitrous acid and nitric acid, in the denitrification tank 10, the denitrifying bacteria use nitrous acid and nitric acid, and the organic matter in the waste water is used as a hydrogen donor, and nitrous acid is used. Denitrification treatment is performed in which nitric acid is reduced to harmless nitrogen gas and released into the air.

  Here, the stirrer 13 is not necessarily provided in the denitrification tank 10. For example, you may stir by stirring means, such as a pump.

  The treated water treated in the denitrification tank 10 flows into the nitrification tank 11. An aeration air pipe 14 is provided at the bottom of the nitrification tank 11. Since the inside of the nitrification tank 11 is aerated by the aeration air pipe 14, the inside of the nitrification tank 11 is in a state where the dissolved oxygen concentration is high (aerobic state) and is adsorbed by the bioreactor element 1 in the presence of ammoniacal nitrogen. Among the immobilized microorganisms, nitrifying bacteria increase the growth.

  Here, the aeration air pipe 14 is not necessarily provided in the nitrification tank 11. However, since nitrifying bacteria require a condition in which the dissolved oxygen concentration is higher than that of other heterotrophic bacteria, in order to adsorb and immobilize more nitrifying bacteria in the bioreactor element 1, the aeration air tube 14 is used. It is preferable to aerate the inside of the provided nitrification tank 11.

  The grown nitrifying bacteria perform nitrification treatment using oxygen in the nitrification tank 11 to oxidize ammonia contained in the treated water supplied from the denitrification tank 10 to nitrous acid or nitric acid.

  A part of the treated water from the nitrification tank 11 is circulated to the denitrification tank 10, and the other part flows into the precipitation tank 12. In the sedimentation tank 12, the solid (sludge) in the treatment liquid from the nitrification tank 11 is precipitated and separated, and the supernatant water from which the sludge has been removed is discharged to the outside as treated water. On the other hand, the precipitated sludge precipitated at the bottom of the settling tank 12 is discharged out of the system as excess sludge and treated as waste.

  Here, it is not always necessary to discharge all of the precipitated sludge precipitated at the bottom of the settling tank 12 out of the system as surplus sludge and treat it as waste. For example, a part of the excess sludge can be returned to the denitrification tank 10 as return sludge and denitrification treatment can be performed.

  As described above, the bioreactor element to which the present invention is applied and the wastewater treatment method using the bioreactor element can adsorb and immobilize microorganisms in a short time while saving space and low cost. The processing capacity is high.

DESCRIPTION OF SYMBOLS 1 Bioreactor element 2 Inner network 3 Outer network 4 Peripheral junction 5 First direction junction 6 Second direction junction 7 Wastewater treatment tank 8 Support frame 9 Wastewater treatment device 10 Denitrification tank 11 Nitrification tank 12 Precipitation tank 13 Stirrer 14 Aeration air pipe 15 Small compartment 101 Bioreactor 102 Hollow fiber 103 First layer 104 Second layer

Claims (2)

A first net that is arranged such that a filament made of polyethylene containing a porous material forms a mesh;
A second mesh that is formed by laminating the first mesh so as to sandwich the first mesh, the filaments made of polyester forming a mesh, adjacent to the front and back surfaces of the first mesh, respectively;
An outer peripheral edge of the first mesh body, and a peripheral joint part that joins a portion where the second mesh body overlaps;
A first direction joint for joining the first mesh and the second mesh in the stacking direction at a predetermined interval in a first direction along the outer peripheral portion of the second mesh;
The first mesh and the second mesh are joined in the stacking direction at a predetermined interval in a second direction substantially orthogonal to the first direction along the outer peripheral portion of the second mesh. A bioreactor element comprising: a second direction junction . A first mesh that is arranged so that a filamentous material made of polyethylene containing a porous material forms a mesh, and a filamentous material that is made of polyester forms a mesh, adjacent to the front and back surfaces of the first mesh, respectively. A step of adsorbing and immobilizing microorganisms in a bioreactor element composed of a second network layered and arranged so as to sandwich the first network body;
Placing the bioreactor element on which microorganisms are adsorbed and immobilized in a wastewater treatment tank, and performing a predetermined wastewater treatment.
Wastewater treatment method using a bioreactor element.

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