JPH081182A - Organism-immobilized carrier for sewage treatment - Google Patents

Abstract

PURPOSE:To bond both of aerobic and anaerobic organisms in good balance to efficiently purify sewage by taking a measure setting the average void size of open voids in an aerobic organism-immobilized part so as to make the same larger than the average pore size of the pores in an anaerobic organism- immobilized part by a specific numerical value range. CONSTITUTION:Aerobic organism-immobilized parts 11 each obtained by bonding a large number of carrier raw material solids so as to form open voids and an anaerobic organism-immobilized part 12 having pores substantially surrounded by the aerobic organism-immobilized parts 11 are formed on an organism- immobilized carrier 10 purifying sewage by biological treatment. The average void size of the open voids of the aerobic organism-immobilized parts 11 is set so as to be made larger than the average pore size of the pores of the anaerobic organism-immobillzed part 12 by 2-10mm while the voids of the aerobic organism immobilized parts 11 are set so as to be made smaller than the space ratio of the anaerobic organism-immobilized part 12 by 10-50%. By this constitution, an aerobic organism and an anaerobic organism are bonded in good selectivity and balance and sewage is efficiently purified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biological immobilization carrier for treating sewage for purifying sewage such as industrial effluent, domestic effluent or the like or sewage in rivers contaminated by these various effluents by biological treatment.

[0002]

2. Description of the Related Art As a method for purifying various kinds of waste water or sewage in rivers, a biological treatment method of treating with a microorganism has been known. As such a biological treatment method, a method has been proposed and carried out in which microorganisms are held in activated sludge or a biological fixed carrier, sewage is subjected to contact treatment, and flocculated to precipitate or separate and remove. Such bio-immobilized carriers include, for example, biofilms formed of fibrous materials having a large surface area, non-woven fabric moldings or ropes; porous materials such as activated carbon, zeolite, and mospite; special synthetic materials having a large surface area on rod-shaped plastic materials. Form in which fibers are entwined in a spiral shape; crushed stone aggregates in which two or more quarries are aggregated and joined to form pores are proposed, and in order to perform the inter-gravel catalytic oxidation method, the bottom floor of rivers, etc. It has also been proposed that a gravel bed directly laying gravel on it, a concrete box body having a plurality of wastewater inflow / outflow ports filled with a plurality of crushed stones, and the like.

However, with conventional porous materials or crushed stones, both aerobic and anaerobic organisms cannot be immobilized with high selectivity, and anaerobic organisms are immobilized. There is a problem that sludge is clogged in the part where On the other hand, in the case of the bio-immobilized carrier using the fibers, it is possible to sufficiently immobilize the microorganisms and easily remove or precipitate the floc-like substance after the wastewater treatment. However, since it is necessary to float the sewage in a sewage flow or fix it to a special device, there are problems that the installation location is limited and the installation method becomes complicated.

[0004]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is that the attachment rate and growth rate of microorganisms are extremely high, and that aerobic and anaerobic organisms can be attached in a well-balanced and highly selective manner, and the efficiency can be improved. An object of the present invention is to provide a biological fixed carrier for purifying sewage capable of purifying sewage. Another object of the present invention is to provide a biological fixed carrier for sewage purification that can reduce clogging of sludge during sewage treatment.

[0005]

According to the present invention, there is provided a biological fixed carrier for purifying sewage by biological treatment, wherein a plurality of carrier raw material solids are used to form continuous ventilation holes. And an aerobic organism fixing part joined to, and an anaerobic organism fixing part having pores substantially surrounded by the aerobic organism fixing part, the average pore diameter of the continuous vents in the aerobic organism fixing part is , 2 to 10 mm larger than the average pore diameter of the pores in the anaerobic organism fixing part, and the porosity of the pores in the aerobic organism fixing part is 10 to 50% smaller than the porosity in the anaerobic organism fixing part. A biological fixed carrier for treating wastewater is provided.

The present invention will be described in more detail below. The biological immobilization carrier for sewage purification of the present invention has a specific aerobic organism fixing part and a specific anaerobic organism fixing part substantially surrounded by the aerobic organism fixing part. In this case, substantially enclosed means that the anaerobic organism fixing part does not exist outside the aerobic organism fixing part, and the anaerobic organism fixing part exists outside the aerobic organism fixing part. , The anaerobic organisms are not efficiently fixed and the fixing rate of the microorganisms themselves on the carrier is lowered.

In the sewage purification organism-immobilizing carrier of the present invention, the aerobic organism-immobilizing part is formed by joining a plurality of carrier-material solids so as to form continuous vent holes by the respective carrier-material solids. It is a part that selectively fixes aerobic organisms. At this time, the selective fixation of aerobic organisms means that preferably 50% or more, and particularly preferably 60% or more, of the microorganisms to be immobilized are aerobic organisms.

Examples of the solid material of the carrier raw material constituting the aerobic organism fixing part include crushed stone, ceramics, blast furnace slag, porcelain pieces, crushed concrete blocks, plastics, etc., and in terms of cost and environment, It is preferable to use industrial waste such as ceramic pieces.

The material, size, shape and the like of the solid carrier raw material are not particularly limited as long as it has a specific gravity that does not float in water, but the normal size is usually an average diameter of 1 to 30 cm.
It is preferred that In addition, in order to bond the carrier raw material solids, a plurality of carrier raw material solids may be bonded with cement, an adhesive, or the like so that communication holes are formed in the spaces between the carrier raw material solids. That is, the surface portions of the respective carrier raw material solids are not all adhered to each other, and the gaps formed by the surfaces of the respective carrier raw material solids other than the joint portion form the continuous air holes. As the adhesive for bonding the solid material of the carrier material, a known adhesive can be used depending on the material, and particularly for adhering industrial waste such as ceramic pieces, an epoxy-based polymer mortar adhesive, etc. Can be preferably used. At this time, the communication holes of the aerobic organism fixing part formed by the gaps of the respective carrier raw material solids may have communication holes communicating with the anaerobic organism fixing part described later, and all of them are necessarily communication holes. It doesn't have to be. The pore diameter of the continuous vents is not particularly limited, but the average pore diameter of the continuous vents in the aerobic organism fixing part is 3 to 1
It is preferably 7 mm, especially 5 to 13 mm. Further, the porosity of the continuous vents of the aerobic organism fixing part is 30 to 88%,
It is particularly preferably 40 to 88%. When the average pore diameter and the porosity are out of the above ranges, the fixing rate of aerobic organisms is lowered, which is not preferable. At this time, the values of the average pore diameter and the porosity are preferably appropriately selected within the above range, but the average pore diameter of the anaerobic organism fixing portion described later and the porosity are provided so as to provide a difference described later. You have to choose.

Flocking may be applied to the surface portion of the solid material of the carrier raw material. Examples of the flocked material include nylon, rayon, cotton, polyethylene, polypropylene,
A fibrous material such as acrylic, particularly preferably, the inside of the fiber is porous, has air permeability, exhibits a capillary action, and has a function of absorbing water, for example, trade name "Aqualon"
This can be performed by adhering a porous fiber material such as (manufactured by Kanebo Co., Ltd.). The fiber diameter of the fiber material is preferably 3 to 15 denier, and the fiber length is 3 to 10 mm.
Is desirable. If the fiber length is less than 3 mm, the amount of adhered microorganisms is not sufficient, and if it exceeds 10 mm, the flocs of microorganisms are easily peeled off, which is not preferable. Further, it is desirable that the amount of fibers to be transplanted is 50 to 200 g / cm ² .

The above-mentioned flocking is carried out by, for example, a known emulsion-type or solvent-type adhesive, specifically vinyl-based, ethylene-based, acrylic-based
By applying an adhesive such as melamine-based, urethane-based, epoxy-based, polyester-based, vinyl acetate-based, polyamide-based, rubber-based, silicon-based, etc., and then flocking a required amount of fibrous material by electrostatic flocking, etc. Can be done.

In the sewage treatment organism-immobilizing carrier of the present invention, the anaerobic organism-immobilizing part has pores substantially surrounded by the aerobic organism-immobilizing part for selectively immobilizing anaerobic organisms. It is a part. Selectively fixing an anaerobic organism means preferably 10 to 30% of fixed microorganisms.
However, it is particularly preferable that 20 to 50% is an anaerobic organism. The fixing rate of this anaerobic organism is only less than about 5% in the case of a conventional organism fixing carrier in which crushed stones etc. intended to fix an aerobic organism are aggregated and joined with an adhesive, and the aerobic organism is fixed. In the organism fixing carrier capable of sufficiently fixing the above-mentioned, the sufficient effect can be obtained even when the anaerobic organism fixing rate is 10% or more. The effect of such anaerobic organism fixation can be confirmed by, for example, a decrease in the amount of chlorophyll.

As the anaerobic organism fixing portion, for example, porous urethane foam, a porous cushion material obtained by processing polyethylene fibers or the like into a three-dimensional three-dimensional spring structure, or a form in which synthetic fibers or the like are three-dimensionally entangled , Materials having flexibility and continuous vents such as various porous sponges; hollow spheres, hollow polyhedra, etc., hollow bodies made of plastic or the like having pores on the surface; In addition, the material etc. which put the material which has the said flexibility and has a continuous ventilation hole can be mentioned. The pore size of the pores in the anaerobic organism fixing part is not particularly limited, but the average pore size in the anaerobic organism fixing part is 1 to
It is preferably 15 mm, especially 2 to 10 mm. The porosity of the anaerobic organism fixing part is preferably 50 to 98%, particularly preferably 70 to 98%. At this time, the porosity of the hollow body having pores on the surface is 70 to 98%, particularly 80.
~ 98% is preferable. If the average pore diameter and the porosity are out of the above ranges, the fixing rate of anaerobic organisms is lowered, which is not preferable. Further, the average pore diameter and the porosity need to be set so that the average pore diameter and the porosity of the aerobic organism fixing part have a difference described later.

The biological immobilization carrier for treating sewage according to the present invention comprises the aerobic organism immobilization part and the anaerobic organism immobilization part substantially surrounded by the aerobic organism immobilization part. The average pore diameter of the continuous ventilation holes in the section is 2 to 10 mm from the average pore diameter of the pores in the anaerobic organism fixing section.
It is large, preferably 3 to 5 mm, and the porosity of the pores in the aerobic organism fixing part is 10 to 50% smaller than the porosity in the anaerobic organism fixing part, preferably 2
It is 0 to 30% smaller. The average pore diameter of the aerobic organism fixing portion, the difference between the average pore diameter of the anaerobic organism fixing portion, and the porosity of the aerobic organism fixing portion, the difference between the void ratio of the anaerobic organism fixing portion. Is outside the above range,
The selectivity and adhesion amount of each microorganism in the aerobic organism fixing part and the anaerobic organism fixing part are lowered, and highly efficient wastewater treatment is impossible. In addition, when the anaerobic organism fixing part is not substantially surrounded by the aerobic organism fixing part, the adherence and fixing rate of the aerobic organism and the anaerobic organism decreases.

In order to prepare the biological fixed carrier for treating sewage of the present invention, for example, a method of forming an aerobic biological fixed portion around the anaerobic biological fixed portion, a plurality of carrier raw materials having hollow portions inside. After the solid matter is joined to form the aerobic organism fixing part, the anaerobic organism fixing part of the material having the flexibility and having the continuous vent is inserted from the pore having a large pore diameter of the aerobic organism fixing part. Then, a method of filling the hollow portion, to prepare a plate-shaped aerobic organism fixing portion, laying an anaerobic organism fixing portion on the plate-shaped aerobic organism fixing portion, the anaerobic organism fixing portion It can be manufactured by a method of providing an aerobic organism fixing portion on the upper surface portion and the side surface portion. At this time, the shape and size of the biological fixed carrier for sewage treatment can be appropriately selected depending on the purification place, purification method, etc. of the sewage, and the surface portion thereof has an uneven shape formed by joining a plurality of fixed raw material carriers. Thus, it can be formed into a shape having a substantially plate-like shape, a spherical shape, a polygonal shape, or the like.

The biological fixed carrier for treating sewage of the present invention can be used by arranging it at a position where it comes into contact with sewage. In order to perform the sewage treatment more efficiently, microorganisms and / or microorganisms to be treated in advance are treated. A nutrient source for the microorganism,
Specifically, ammonium salts, nitrites, nitrates, phosphates, etc. are used for the surface part of the biological immobilization carrier for sewage treatment, the inner surface of the pores of the aerobic organism fixing part, the inner surface of the pores of the anaerobic organism fixing part, etc. It is also possible to use it after holding it in. In order to retain the microorganisms and / or the nutrient source of the microorganisms on the biological fixed carrier for treating sewage, it is carried out by, for example, immersing in a solution containing the microorganisms and / or the nutrient source of the microorganisms, or by spraying the solution. be able to.

In order to perform sewage treatment using the biological immobilization carrier for sewage treatment of the present invention, if the sewage can be brought into flow contact with the biological immobilization carrier for sewage treatment, it is arranged at an appropriate location by a known method. Can be done. Specifically, for example, a method for disposing sewage treatment organism fixed carrier in place of gravel such as gravel and crushed stone in the conventional gravel contact oxidation treatment,
Method of laying directly on the bottom floor of the river, provided with inflow and outflow of sewage, box body, conduit, such as a frame body such as a column, filled with the biological fixed carrier for sewage treatment or in the place of contact with sewage, for example, plate-like A wastewater purifying device disposed in place of a crushed stone or the like in a known method of treating wastewater by circulating wastewater in a river or industrial wastewater, domestic wastewater, etc. For example, sewage can be brought into contact with the biological fixed carrier.

At this time, since the organism-fixing carrier does not float in water, it can be installed in the same manner as conventional crushed stone. In addition, the bio-immobilized carrier can selectively attach aerobic and anaerobic organisms with good efficiency, and thus can treat both aerobic organisms and anaerobic organisms. Furthermore, particularly when the anaerobic organism fixing part having a hollow part is used, it is possible to effectively prevent clogging of sludge and the like during sewage treatment. Further, when the aerobic organism-fixing part of the organism-immobilizing carrier is flocked, flock of sewage is efficiently attached to the flocked part, and the flock-like substance is contained to some extent (flow velocity of sewage, weight of flock-like substance). However, it is not necessary to perform the work of peeling the floc-like substance from the biological fixed carrier, because the growth is naturally peeled off from the transplanted portion and the sedimentation or flow occurs when the growth is increased. Therefore, it can be used semipermanently depending on the installation method.

[0019]

EFFECTS OF THE INVENTION Since the biological immobilization carrier for treating sewage of the present invention is provided with a specific aerobic organism fixing part and an anaerobic organism fixing part in a specific arrangement, aerobic organisms and anaerobic organisms have good selectivity. Moreover, it is highly efficient and can be attached in a well-balanced manner to treat sewage. Also, clogging of sludge is less likely to occur. Therefore, almost no maintenance or the like is required, and the wastewater can be purified with high efficiency.

[0020]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples below, but the present invention is not limited thereto.

[0021]

[Example 1] A product name "Curl Rock" (manufactured by Toa Boseki Co., Ltd., average pore diameter 3 mm, porosity 95%) obtained by processing polyethylene fibers into a three-dimensional three-dimensional spring structure was formed into a spherical shape having a diameter of about 60 mm. After processing, an anaerobic organism fixing part was prepared. Next, after applying an epoxy-based polymer mortar adhesive having a trade name “TSK mortar bond” (manufactured by Taisei Sangyo Co., Ltd.) to the surfaces of a plurality of ceramic pieces that are 10 to 30 mm square industrial waste, A biological fixed carrier of a ceramic piece aggregate having a diameter of about 120 mm was prepared which was adhered so as to surround the periphery of the anaerobic organism fixing part so that the surfaces were not completely joined and provided with the anaerobic organism fixing part inside. The average pore diameter of the pores formed by the gaps between the individual ceramic pieces of the obtained biologically fixed carrier was 7 mm, and the porosity was 70%. The ceramic piece part of the biological fixed carrier is
Corresponds to the aerobic organism fixation part. Further, the aerobic organism fixing part formed of each ceramic piece and the anaerobic organism fixing part have continuous ventilation holes. Next, width 30 cm, depth 30 cm,
It is a rectangular parallelepiped with a length of 1 m, and the raw water inlet of the waste water is provided at the bottom of the side surface at one end, and the treated water outlet is provided at the upper part of the opposite side surface. . Next, sewage was circulated for 20 days at a flow rate of 8 to 9 mm / s. S for sewage at raw water inlet and treated water outlet
S (suspended matter), COD (chemical oxygen consumption) and chlorophyll content were measured. Table 1 shows the results. A partially transparent perspective view of the obtained biologically fixed carrier is shown in FIG. In FIG. 1, 10 is a biological fixing carrier, 11 is an aerobic biological fixing part, and 12 is a see-through anaerobic biological fixing part.

[0022]

[Comparative Example 1] An epoxy-based polymer mortar adhesive having a trade name of "TSK mortar bond" (manufactured by Taisei Sangyo Co., Ltd.) was applied to the surface of a plurality of ceramic pieces, which were industrial wastes of 10 to 30 mm square, and then ceramic The pieces were adhered so that the respective surfaces were not completely joined, and a ceramic piece aggregate having a diameter of about 120 mm was prepared. The average pore diameter of the pores formed by the gaps between the ceramic pieces of the obtained aggregate was 7 mm, and the porosity was 70%. Most of the holes of the aggregate were communication holes communicating with the inside. Next, in the same manner as in Example 1, a plurality of the obtained ceramic piece aggregates were filled in a tank and each measurement was performed. The results are shown in Table 1.

[0023]

Comparative Example 2 An adhesive of trade name "TSK Mortar Bond" (manufactured by Taisei Sangyo Co., Ltd.) was applied to the surface of the ceramic piece aggregate prepared in Comparative Example 1. Next, electrostatically absorb water-absorbing acrylic fiber (product name "Aqualon", manufactured by Kanebo Ltd.) having a fiber length of 3 mm and a fiber diameter of 20 densi at a rate of 50 g / cm ² by using an electrostatic flocking machine (manufactured by Mesac). Flocked,
A sewage contact material having an average porosity of 65% was prepared. Next, in the same manner as in Example 1, a plurality of the obtained sewage contact materials were filled in a tank and each measurement was performed. The results are shown in Table 1.

[0024]

[Comparative Example 3] A product name "Curl Rock" (manufactured by Toa Boseki Co., Ltd., average pore diameter 3 mm, porosity 95%) obtained by processing polyethylene fibers into a three-dimensional three-dimensional spring structure was formed into a spherical shape having a diameter of about 60 mm. It processed and prepared the sewage contact material. Next, in the same manner as in Example 1, a plurality of the obtained sewage contact materials were filled in a tank and each measurement was performed. The results are shown in Table 1.

[0025]

COMPARATIVE EXAMPLE 4 A plurality of 100 mm square foamed plastic materials having open pores having an average pore diameter of 9 mm and a porosity of 40% were filled in a tank in the same manner as in Example 1, and each measurement was performed. The results are shown in Table 1.

[0026]

[Comparative Example 5] Twenty biological fixed carriers in which polyethylene fibers having a fiber diameter of 10 denier and a fiber length of 5 mm were planted on the entire string having a diameter of about 8 mm and a length of 200 mm produced by twisting plastic fibers were used in Example 1. Each measurement was carried out in the same manner as in Example 1 except that the wastewater was brought into contact with the raw water while being suspended in the tank used. The results are shown in Table 1.

[0027]

[Table 1]

From the results shown in Table 1, it was found that SS, COD and chlorophyll can be effectively removed in Example 1 having the aerobic organism fixing part and the anaerobic organism fixing part. In addition, the organism-immobilizing carrier of Example 1 has a COD removal effect equivalent to or higher than that of the wastewater contacting materials of Comparative Examples 1 and 2 having a high COD removal rate which is considered to have a high aerobic organism fixation rate. It can be seen that the chlorophyll removal effect was obtained more than the sewage contacting material of Comparative Example 3 in which the amount of chlorophyll was largely reduced and anaerobic organisms seemed to be immobilized. Therefore, it can be estimated that the bio-immobilized carrier of Example 1 was able to immobilize both aerobic organisms and anaerobic organisms with high efficiency, and it was also found that the suspended solids (SS) were excellent.

[Brief description of drawings]

FIG. 1 is a partially transparent perspective view showing a biological fixed carrier used in Example 1. FIG.

Claims (4)

[Claims] 1. A biological fixed carrier for purifying sewage by biological treatment, wherein a plurality of carrier raw material solids are joined so as to form continuous ventilation holes with the respective carrier raw solids, and an aerobic biological fixing unit. And an anaerobic organism fixing part having pores substantially surrounded by the aerobic organism fixing part, the average pore diameter of the continuous vents in the aerobic organism fixing part, the pores in the anaerobic organism fixing part 2 to 10 mm larger than the average pore diameter of the aerobic organisms, and the porosity of the pores in the aerobic organism fixing part is 10 to 50% than the porosity in the anaerobic organism fixing part.
A biological fixed carrier for treating sewage, which is small. 2. The organism-fixing carrier for treating wastewater according to claim 1, wherein the anaerobic organism-immobilizing portion has flexibility and has an air vent. 3. The biological fixed carrier for sewage treatment according to claim 1, wherein the anaerobic biological fixed part is a hollow body having pores on its surface. 4. The biological fixed carrier for sewage treatment according to claim 1, wherein the biological fixed carrier holds a microorganism for treating sewage and / or a nutrient source of the microorganism.