JP2009072767A - Activated sludge apparatus and treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an activated sludge apparatus capable of treating water even with a small filling amount of fixed carriers under a high BOD load, giving a low rate of sludge generation even in operation under a high BOD volume load, and preventing treated water quality from deterioration, and to provide a treatment method. <P>SOLUTION: The activated sludge apparatus for treating water containing an organic matter comprises an aeration tank 1, a biological treatment tank 2 and a settling tank 3 which are serially disposed in the direction from the upstream to the downstream side. The biological treatment tank 2 includes fixed carriers 4, an aeration means 7 and a baffle plate 5 separating both. The apparatus further comprises a returning means for returning the sludge in the settling tank 3 to the biological treatment tank 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an activated sludge apparatus for treating organic substance-containing water and a method for treating organic substance-containing water with an activated sludge apparatus.

An activated sludge apparatus having a fixed carrier in a biological treatment tank is often used for treatment of organic substance-containing water. Since the activated sludge suspended solid concentration (MLSS concentration) can be increased to 5000 to 10000 mg / L with respect to 2000 to 5000 mg / L of the conventional activated sludge method, the BOD processing capacity per volume of the processing tank can be increased. . It also has the advantage that less excess sludge is generated. Patent Documents 1 and 2 disclose fixed carriers of various materials and shapes, and an activated sludge apparatus in which a biological treatment tank is divided into one to several. The fixed carrier is usually filled in most biological treatment tanks, but the fixed carrier used in the biological treatment tank is expensive. If the amount of the fixed carrier is reduced in order to reduce the cost, there is a problem that the BOD processing capacity per volume is reduced or excess sludge is increased.
JP 09-252770 A JP-A-10-99892

  In view of such circumstances, the problem to be solved by the present invention is that the activated sludge apparatus has a high BOD processing capacity per volume and can prevent an increase in excess sludge even when the amount of the fixed carrier is small. It is to provide a processing method.

  In the activated sludge apparatus for treating the organic matter-containing water, the present invention has been intensively studied with respect to the above-mentioned problems. A biological treatment tank and a sedimentation tank, the biological treatment tank has a fixed carrier, an air diffuser, and a baffle plate for separating the two, and the sludge from the sedimentation tank is returned to the biological treatment tank. The present invention has been completed by obtaining the knowledge that the above problem can be solved by the configuration further comprising means.

That is, the present invention is as follows.
1. An activated sludge apparatus for treating organic substance-containing water, comprising an aeration tank, a biological treatment tank, and a sedimentation tank arranged in series in an upstream to downstream direction, wherein the biological treatment tank is a fixed carrier, An activated sludge apparatus, further comprising a return means for returning the sludge of the settling tank to the biological treatment tank, having an air diffuser and a baffle plate for separating both.
2. The biological treatment tank is divided into two or more. The activated sludge apparatus described in 1.
3. 3. The fixed carrier according to 1 or 2, wherein the fixed carrier comprises a core material and a fibrous material partially fixed to the core material, and the fixed carrier is configured by closely growing the fibrous material around the core material. Activated sludge equipment.
4). The fixed carrier has a spiral shape. ~ 3. The activated sludge apparatus according to any one of the above.
5). 2. The fibrous material is polyvinylidene chloride. Or 4. The activated sludge apparatus described in 1.
6). An organic matter-containing water treatment method comprising: a step of aeration treatment of the organic matter-containing water; a biological treatment tank having a fixed carrier, an air diffuser, and a baffle plate that separates both; A method for treating organic substance-containing water, comprising a step of aeration and biological treatment without contact with a fixed carrier, a step of separating sludge in a sedimentation tank, and a step of returning the separated sludge to the biological treatment tank.

  The activated sludge apparatus and the treatment method of the present invention have the effect that the BOD treatment capacity per volume is high even when the amount of the fixed carrier filled is small, and an increase in excess sludge can be prevented.

  The following embodiment is an example for explaining the present invention, and is not intended to limit the present invention only to this embodiment. The present invention can be implemented in various forms without departing from the gist thereof.

Below, embodiment of the activated sludge apparatus and the processing method of this invention is described in detail.
The present invention relates to an activated sludge apparatus and a treatment method for treating organic substance-containing water. The activated sludge apparatus in the present invention is an apparatus that biodegrades organic matter and the like contained in water with microorganisms and the like present in the activated sludge and solid-liquid separates the activated sludge with a sedimentation tank to obtain clear treated water.
FIG. 1 shows a schematic view of one preferred embodiment of an activated sludge apparatus for treating organic substance-containing water according to the present invention. As shown in FIG. 1, the biological treatment tank 2 which has the aeration tank 1 arrange | positioned in series from the upstream to the downstream direction where organic substance containing water flows, and the baffle plate which isolate | separates both a fixed support | carrier and an aeration means, And a sedimentation tank 3. Furthermore, the activated sludge apparatus of this invention is provided with the sludge return pipe | tube 6 which is a means to return the sludge in the said sedimentation tank to the biological treatment tank which has a fixed support | carrier.

As the aeration tank in the activated sludge apparatus of the present invention, those used in a normal activated sludge method can be used. In the aeration tank, the BOD component in the organic substance-containing water can be oxidatively decomposed to about 70 to 95%. BOD volume load of the aeration tank, 1 kg / m ³ · day or more, for example, be a 1~20kg / m ³ · day.
The hydrodynamic residence time (HRT) in the aeration tank of the present invention can be 24 h or less, for example, 0.5 to 24 h. The sludge concentration (MLSS) varies depending on the BOD concentration of the inflowing organic substance-containing water, and can be usually 100 to 10,000 mg / L. The water temperature of the aeration tank is preferably 15 to 40 ° C, more preferably 20 to 37 ° C, and further preferably 25 to 35 ° C. The pH of the aeration tank can be carried out in a fairly wide range, and a pH range of 6 to 8 is preferred. The dissolved oxygen (DO) in the aeration tank is preferably 0.2 mg / L or more, and more preferably 1 mg / L or more. As an air or oxygen aeration method, an air diffuser or mechanical aeration can be used. In the case of using an air diffuser, a swirling flow method or a full aeration method can be used. Examples of the mechanical aeration include a mechanical stirring method and an ejector method. When the BOD volumetric load is large, it is preferable to use an efficient aeration method.

  In the aeration tank of the present invention, when nitrogen or phosphorus is insufficient in the organic substance-containing water, it is preferable to add nitrogen or phosphorus as a nutrient source. The aeration tank may be a multistage process having two or more stages as required. In addition, a carrier such as a fluid carrier or a fixed carrier may be included as necessary, but a fluid carrier is preferable because aeration is necessary to decompose a large amount of BOD components. Examples of the fluid carrier include a gel carrier, a plastic carrier, and a fibrous carrier. One type of carrier or two or more types of carriers can be used in combination. Examples of the material for the fluid carrier include polyethylene glycol, polyvinyl alcohol, acrylamide, polyethylene, polypropylene, polyurethane, cellulose, and polyester. Examples of the shape of the fluid carrier include spheres, cubes, cylinders, and porous bodies. The size of the fluid carrier is preferably 1 to 20 mm, and more preferably 3 to 10 mm. When using a fluid carrier, it is preferable to separate it with a screen. The filling rate of the fluid carrier is preferably 1 to 50% of the tank volume, and more preferably 2 to 20%.

  As the fixed carrier used in the aeration tank, a fixed carrier described in the section of the biological treatment tank later can be used. The fluid carrier or the fixed carrier may be provided in the entire aeration tank, but it is effective to have it in a part of the tank. The return sludge from the sedimentation tank or biological treatment tank to the aeration tank is not usually required, but it is necessary to add the return sludge to the aeration tank when the amount of inflowing organic matter-containing water or the BOD component is greatly reduced. Therefore, a means to add the return sludge to the aeration tank will be installed.

  In this case, the amount of returned sludge can be set to 1 or less, for example, 0.01 to 1 in terms of the volume ratio with respect to the amount of water containing organic matter. In addition, in order to keep the components and processing amount of the organic substance-containing water flowing into the aeration tank uniform, it is preferable to install an adjustment tank in front of the aeration tank. The capacity of the adjustment tank can be determined in consideration of the inflow amount and the fluctuation pattern of the inflow component, the flow rate fluctuation allowable width after the flow rate adjustment, and the like. In addition, when the organic substance-containing water contains components that impede biological treatment such as suspended solids (SS), oil, and toxic metals, a precipitation tank, a pressure levitation device, a coagulation sedimentation tank are placed in front of the aeration tank. It is preferable to install pretreatment means such as the above.

  The biological treatment tank in the activated sludge apparatus of the present invention has a fixed carrier, an air diffuser, and a baffle plate that separates both. The biological treatment tank of the present invention may have any configuration as long as the wastewater from the previous aeration tank flows in, and as illustrated in FIG. 1, the organic substance-containing water that has been aerated in the aeration tank is overflowed, It is preferable to flow into the biological treatment tank.

In the biological treatment tank used in the present invention, in addition to BOD removal, COD removal, nitrogen removal, and phosphorus removal, sludge self-digestion, predation, and sludge flocification are performed. The biological treatment tank can take various forms and operating conditions depending on what it is desired to remove. The biological treatment tank may be a multistage process having two or more stages as necessary. In order to reduce the generation of excess sludge in the biological treatment tank and to prevent filamentous bulking, a multi-stage process of two or more stages is preferable. From the viewpoint of efficiently establishing a food chain and from the viewpoint of cost, 3-6. A step is more preferred. If the main purpose is to remove BOD, only the aerobic process may be used. The BOD volume load of the biological treatment tank for performing the aerobic process is 5 kg / m ³ · day or less, for example, 0.05 to 5 kg, because most of the BOD components in the organic substance-containing water are removed in the previous aeration tank / M ³ · day. The HRT of the biological treatment tank can be 48 h or less, for example, 1 to 48 h. MLSS can be normally 2000-20000 mg / L, and it is preferable to carry out at 5000-20000 mg / L. 15-40 degreeC is preferable, as for the water temperature of a biological treatment tank, 20-37 degreeC is more preferable, and 25-35 degreeC is further more preferable. The pH can be carried out in a fairly wide range, and a pH range of 6-8 is preferred. The DO of the biological treatment tank is preferably 0.2 mg / L or more, and more preferably 1 mg / L or more.

  In the biological treatment tank used in the present invention, an anaerobic process can be further provided for the purpose of removing nitrogen and phosphorus. When nitrogen removal is necessary, the denitrification and nitrification can be performed in two stages, denitrification, nitrification, second denitrification, and second nitrification in four stages. The water temperature in the nitrification step is preferably 10 to 35 ° C, more preferably 20 to 30 ° C. The pH of the biological treatment tank is preferably 6.8 to 8.5, the DO of the biological treatment tank is preferably 2 mg / L or more, and the sludge residence time (SRT) of the biological treatment tank is preferably 7 days or more. When the BOD component is insufficient in the denitrification process, a BOD source such as methanol can be added, or organic substance-containing water containing the BOD component can be step-fed.

  The biological treatment tank used in the present invention has a fixed carrier. The fixed carrier is used for the growth of various microorganisms such as protozoa and metazoans, as well as bacteria, because the biological treatment tank is responsible for various biological treatments. The fixed carrier is not particularly limited, but examples of the shape include a honeycomb shape, a spiral shape, a hollow shape, a sponge shape, a mesh shape, a rod shape, and a linear shape, because many microorganisms can inhabit and the flow of the biological treatment tank is improved. A helical form is preferred. Also preferred is a fixed carrier composed of a core material and a fibrous material partially fixed to the core material, wherein the fibrous material is densely formed around the core material. The shape of the core material is not limited, but a fixed carrier in which the core material has a spiral shape is preferable. A metal such as soft iron, aluminum, or copper, or a plastic such as soft vinyl chloride can be used for the core material. The metal core can be waterproofed or plastic coated to prevent corrosion. The diameter of the core material varies depending on the material, and is preferably 1 mm or more and 7 mm or less. Furthermore, the material of the fibrous material is not particularly limited, and examples thereof include polyethylene, polypropylene, polyester, polyamide, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, and polyurethane. Polyvinylidene chloride has good adhesion to microorganisms. Therefore, it is preferable. The fixed carrier can be used by immersing it in a biological treatment tank in the form of a fixed carrier block in which a plurality of fixed carriers are held on a frame made of a suitable corrosion-resistant material. The height of the fixed carrier block may be a height suitable for the water depth of the biological treatment tank, preferably 0.5 m or more and 6 m or less, more preferably 2 m or more and 4 m or less.

The water depth of the biological treatment tank is not particularly limited, but if the water depth is shallow, the oxygen dissolution efficiency at the time of aeration becomes low, and if the water depth is deep, the pressure loss at the time of aeration becomes high. Therefore, the water depth is preferably 0.5 m or more and 10 m or less, Furthermore, 1.5 m or more and 5 m or less are more preferable.
The filling amount of the fixed carrier in the biological treatment tank can be represented by the fixed carrier filling amount. Here, the fixed carrier filling amount is obtained by dividing the “length of the fixed carrier filled in the biological treatment tank” by the “capacity of activated sludge in the biological treatment tank” and expressing the unit in m / m ³ . The filling amount of the fixed carrier in the biological treatment tank of the present invention is not particularly limited, but is preferably 10 to 100 m / m ^{3 and} more preferably 30 to 70 m / m ³ . In an activated sludge apparatus that does not have an aeration tank as defined in the present invention (for example, the apparatus of FIG. 3 used in the comparative example), a fixed carrier filling amount of 70 to 120 m / m ³ is often used. If it is less than 70 m / m ^{3, the} amount of sludge generated increases and the BOD volumetric load cannot be increased.

The amount of the fixed carrier used is preferably 100 m ² or more and 3000 m ² or less as the surface area of the fixed carrier per 1 m ² of the projected floor area of the fixed carrier block. It is more preferably 100 m ² or more 500 meters ² or less. If it is 100 m ² or more, the installation area efficiency of the apparatus is good, and if it is 500 m ² or less, the air lift effect by aeration is exhibited and a uniform swirling flow consisting of an upflow and a downflow is obtained, and microorganisms are easy to grow. The environment is obtained. The surface area of the fixed carrier is more preferably 250 m ² or more and 350 m ² or less.

  In addition, as the carrier in the biological treatment tank used in the present invention, the fluid carrier described in the section of the aeration tank can be used together with the fixed carrier. The carrier may be provided in the whole biological treatment tank, or it is effective to have the carrier only in a part of the tank. When the biological treatment tank is a multistage process having two or more stages, a process using a fixed carrier and a process using a fluid carrier can be used in combination.

  The biological treatment tank used in the present invention has a baffle plate that separates the fixed carrier and the air diffuser. The baffle plate is used for the purpose of making the swirl flow caused by aeration in the biological treatment tank uniform without bubbles directly hitting the fixed carrier. In particular, when the BOD load is high and the MLSS is set to 10,000 mg / L or more, it is effective to use a baffle plate. It is desirable to install the baffle plate near the fixed carrier block so as to follow the water flow generated by the air diffuser, and to be almost parallel to the partition wall. It is preferable to make the lower end the same position as the lower end of the fixed carrier block at a position of 0.1 to 0.3 m from the liquid surface.

  When a baffle plate is used, the swirl flow rate of the biological treatment tank becomes uniform across the tank, so the flow rate that passes through each fixed carrier installed in the tank also becomes uniform, and sludge adheres uniformly to the fixed carrier. It becomes. Aerobic bacteria propagate on the surface of the attached sludge, facultative anaerobic bacteria propagate inside the sludge, and the microbial ecosystem that forms a well-balanced food chain can be established as the entire attached sludge. As a result, an increase in excess sludge can be prevented. In addition, if the swirl flow rate is uniform, the dissolved oxygen concentration is uniform on the same plane in the tank, and the amount of aeration required to secure the necessary dissolved oxygen concentration in the biological treatment tank is minimized. Can be reduced.

  Since the baffle plate that separates the stationary carrier and the air diffuser is used, bubbles generated from the air diffuser generate an upward flow, and this flow swirls the entire tank. Since the fixed carrier and the air diffuser are separated by the baffle plate, bubbles generated from the air diffuser do not directly contact the fixed carrier and pass through the fixed carrier as a downward flow from above the fixed carrier. As a result, metazoans such as earthworms and bear beetles, protozoan Paramecium and rotifers adhere to the fixed carrier together with sludge, and a food chain can be established.

The sedimentation tank in the activated sludge apparatus of the present invention precipitates and separates the activated sludge mixed solution flowing from the biological treatment tank in the previous stage to obtain a clear treated water. The sedimentation tank of the present invention may be configured so as to flow the wastewater from the biological treatment tank in the previous stage, and as illustrated in FIG. 1, it flows into the sedimentation tank of the present invention due to the overflow of the wastewater in the biological treatment tank. Is preferred.
The adjustment of MLSS can be performed by extracting as excess sludge or by returning the sludge to the biological treatment tank. The amount of excess sludge withdrawn can be set to 5 to 20% by weight ratio to the inflow BOD amount.

  The activated sludge apparatus of this invention is equipped with the means to return the sludge isolate | separated in the sedimentation tank to the biological treatment tank mentioned above. The means for returning the sludge separated in the settling tank is not particularly limited, but a normal sludge pump can be used. The amount of returned sludge is not particularly limited, but if the amount of returned sludge is small, the MLSS of the sedimentation tank becomes too high, and if it is large, the power cost becomes high. The sludge return ratio (capacity ratio) with respect to the organic substance-containing water amount (Q) that has passed through is preferably 1 to 5, more preferably 2 to 4. As described above, the sludge can be returned not only to the biological treatment tank but also to a part of the aeration tank as necessary.

  In the activated sludge apparatus of the present invention, in addition to the tank and means described above, other apparatuses, means, tanks and the like can be provided as needed. Examples of the pretreatment include a stripping device, a pressure levitation device, an oil skimmer, a coagulation sedimentation device, a filtration device, a membrane separation device, and a regulating tank. Examples of the sludge treatment include belt presses, filter presses, centrifugal dehydrators, multiple disk dehydrators, sludge solubilizers, anaerobic digesters, and the like. Post-treatment includes activated carbon adsorption, ozone generator, ultraviolet irradiation device, bactericidal agent addition device, ion exchange device, ion adsorption device, reverse osmosis membrane (RO membrane) and the like. As a means for smoothly performing biological treatment of membrane separation activated sludge apparatus, pH adjustment device, temperature adjustment device, methanol addition device, antifoaming agent addition device, inorganic flocculant addition device, separation membrane chemical cleaning tank, deodorization device, etc. Is mentioned.

Next, the processing method of the organic substance containing water of this invention is demonstrated. The treatment method of the present invention is a biological treatment tank having a step of aeration treatment of the organic substance-containing water, a baffle plate for separating the fixed carrier and the aeration means, and applying air bubbles from the aeration means to the fixed carrier. And a biological treatment process, a step of separating sludge in a sedimentation tank, and a step of returning the separated sludge to the biological treatment tank.
In the aeration process, the organic component of the organic substance-containing water is oxidatively decomposed. In the biological treatment process, aerated organic material-containing water flows into the aeration tank, and in the biological treatment tank having a fixed carrier, in addition to BOD removal, nitrogen removal, and phosphorus removal, self-digestion and predation of sludge, sludge Flocking is performed. Next, in the sedimentation tank, the sludge mixed liquid flowing from the biological treatment tank is separated by sedimentation, and clear treated water is obtained.

  In the treatment method of the present invention, the sludge separated in the sedimentation tank is returned to the biological treatment tank having the fixed carrier, and the biological treatment process in the biological treatment tank described above is performed. Thus, once the sludge once separated is subjected to biological treatment again, generation of excess sludge can be reduced at a high BOD load.

Below, an Example and a comparative example are given and this invention is demonstrated more concretely.
First, analysis methods used in Examples and Comparative Examples of the present invention will be briefly described.
<BOD volumetric load>
The BOD volumetric load is expressed in units of kg / m ³ · day by dividing [weight of BOD component in organic substance-containing water flowed in per day] by [volume of activated sludge in the aeration tank and biological treatment tank]. did.
The sludge generation rate was expressed as a percentage (%) by dividing [weight of the solid content in the extracted sludge] by [weight of the BOD component in the introduced organic substance-containing water].
<Fixed carrier loading amount>
The fixed carrier filling amount is expressed in units of m / m ³ by dividing the “length of the fixed carrier filled in the aeration tank and the biological treatment tank” by the “capacity of activated sludge in the aeration tank and the biological treatment tank”. .

Example 1
The activated sludge apparatus used in this example is shown in FIG. The aeration tank 1 (capacity 6L), the biological treatment tank 2 (capacity 18L), and the sedimentation tank 3 (capacity 4L) are connected in series from upstream to downstream in which the organic substance-containing water flows. Aeration tubes 7 are installed in the aeration tank and the biological treatment tank, respectively, and aeration is possible. The biological treatment tank is equally divided into three stages, and the fixed carrier 4, the air diffuser, and the baffle plate 5 that separates both are installed in the second and third stages. The fixed carrier is made of a polyvinylidene chloride fiber in a loop shape of 1.5 cm in length, and a part thereof is fixed so as to grow densely on a plastic-coated copper core, and is a helical shape having a length of 60 cm and an outer diameter of 8 cm. What was made into was used. The activated sludge in the settling tank is returned to the first stage of the biological treatment tank through the sludge return pipe 6 by the liquid feed pump. The sludge return ratio was 2. The water temperature was 25 ° C. A skim milk aqueous solution (BOD about 1000 mg / L) was used as the organic substance-containing water. After the acclimatization operation for about 3 weeks, an aqueous skim milk solution was introduced at 48 L / day, and the BOD volumetric load was kept constant at 2 kg / m ³ · day. The HRT at this time is 12 hours. The activated sludge in the sedimentation tank was appropriately drawn out and adjusted so that the MLSS in the biological treatment tank was about 10,000 mg / L. The MLSS of the aeration tank was about 300 to 900 mg / L. Since foaming of the aeration tank was observed during the operation period, a nonionic antifoaming agent was appropriately added. Sodium bicarbonate was appropriately added to adjust the pH to about 7. The BOD of the treated water was as good as 5 mg / L or less. In addition, protozoa and metazoans were found in the biological treatment tank, forming a food chain, and the sludge generation rate was as good as 13%. The results are shown in Table 1.

(Example 2)
The activated sludge apparatus used for the present Example is shown in FIG. The first stage of the biological treatment tank was anaerobic treatment. The first stage was not provided with an air diffuser, and a stirring device 10 for stirring sludge was installed. Further, in order to supplement the BOD component for denitrification in the anaerobic treatment, 30% (0.3Q) of the inflowing organic substance-containing water was step-fed to the first stage of the biological treatment tank. Other than that was carried out in the same manner as in Example 1. The total nitrogen (TN) of the treated water was as good as 15 mg / L. Probiotic animals and metazoans lived in the biological treatment tank, forming a food chain, and the sludge generation rate was good at 16%. The results are shown in Table 1.

(Comparative Example 1)
The activated sludge apparatus used in this comparative example is shown in FIG. There is no aeration tank, and the biological treatment tank (capacity 24L) and the sedimentation tank (capacity 4L) are connected in series from upstream to downstream in which the organic substance-containing water flows. The biological treatment tank was equally divided into four stages, and an aeration tube and a fixed carrier were installed in each. Otherwise, the same procedure as in Example 1 was performed. After acclimatization, BOD volumetric load 2 kg / m ³ · day was continued for about 2 weeks, and then filamentous bulking occurred. Thereafter, the BOD volumetric load was lowered to 1.5 kg / m ³ · day. Probable animals and metazoans that flow out of the fixed carrier were observed because of the absence of baffle plates, and the sludge generation rate was as high as 25%. The results are shown in Table 1.

(Comparative Example 2)
Baffle plates were installed in all of the first to fourth stages of the activated sludge apparatus used in Comparative Example 1. Otherwise, the same procedure as in Comparative Example 1 was performed. After acclimatization, BOD volumetric load 2 kg / m ³ · day was continued for about 2 weeks, and then filamentous bulking occurred. Thereafter, the BOD volumetric load was lowered to 1.5 kg / m ³ · day. Compared with Examples 1 and 2, the sludge generation rate was as high as 22% despite a low BOD volumetric load and a large amount of fixed carrier. The results are shown in Table 1.

(Comparative Example 3)
The baffle plate was removed from the biological treatment tank of the activated sludge apparatus used in Example 1. Otherwise, the same procedure as in Example 1 was performed. After acclimatization for about 3 weeks, the BOD volumetric load was kept constant at 2 kg / m ³ · day. Probable animals and metazoans that flow out of the fixed carrier were observed because of the absence of baffle plates, and the sludge generation rate was as high as 25%. The results are shown in Table 1.

  From the results shown in Table 1, it can be understood that the activated sludge apparatus of the present invention has a large BOD volume load and a low sludge generation rate, although the fixed carrier filling amount is smaller than that of the comparative example.

  INDUSTRIAL APPLICABILITY The present invention can be used for industrial wastewater such as food and chemicals, wastewater from dairy facilities, wastewater from restaurant kitchens and households, and public wastewater such as sewage and human waste.

It is explanatory drawing of the activated sludge apparatus of this invention used in Example 1. FIG. It is explanatory drawing of the activated sludge apparatus of this invention used in Example 2. FIG. It is explanatory drawing of the activated sludge apparatus used in the comparative example 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Aeration tank 2 Biological treatment tank 3 Precipitation tank 4 Fixed support | carrier 5 Baffle board 6 Sludge return pipe 7 Aeration pipe 8 Organic substance containing water 9 Treated water 10 Stirring apparatus

Claims (6)

  An activated sludge device for treating organic substance-containing water, comprising an aeration tank, a biological treatment tank, and a sedimentation tank arranged in series in an upstream to downstream direction, wherein the biological treatment tank is a fixed carrier, An activated sludge apparatus further comprising a return means for returning the sludge of the settling tank to the biological treatment tank, having an air diffuser and a baffle plate for separating both.   The activated sludge apparatus according to claim 1, wherein the biological treatment tank is divided into two or more stages.   The fixed carrier is a fixed carrier composed of a core material and a fibrous material partially fixed to the core material, and the fibrous material is densely formed around the core material. The activated sludge apparatus described in 1.   The activated sludge apparatus according to any one of claims 1 to 3, wherein the fixed carrier has a spiral shape.   The activated sludge apparatus according to claim 3 or 4, wherein the fibrous material is polyvinylidene chloride.   An organic matter-containing water treatment method comprising: a step of aeration treatment of the organic matter-containing water; a biological treatment tank having a fixed carrier, an air diffuser, and a baffle plate that separates both; A method for treating organic substance-containing water, comprising a step of aeration and biological treatment without contact with a fixed carrier, a step of separating sludge in a sedimentation tank, and a step of returning the separated sludge to the biological treatment tank.

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