JP6000886B2 - Anaerobic treatment equipment - Google Patents

Description

  The present invention relates to an anaerobic treatment apparatus.

  Conventionally, UASB (Upflow Anaerobic Sludge Blanket) treatment that has granular anaerobic sludge in which anaerobic microorganisms are self-aggregated into fine particles as a treatment device for liquids containing organic components An apparatus is known (see, for example, Patent Document 1). This treatment device holds a granule sludge bed with granule sludge in the lower part of the tank and introduces the liquid to be treated from the lower part of the tank, so that the liquid to be treated flows upward while being in contact with the granule sludge. The organic component of the liquid to be treated is decomposed with granular sludge.

Japanese Patent Laid-Open No. 9-1178

  Here, in the anaerobic treatment apparatus, the granular sludge at the bottom of the sludge bed is in sufficient contact with the organic component of the liquid to be treated and its activity is maintained, but the organic component reacts at the bottom of the sludge bed. As it goes to the upper part of the sludge bed, the concentration of organic components decreases and the granular sludge becomes eutrophication. As a result, the activity of microorganisms in the upper part of the sludge bed decreases, and some microorganisms Will die. For this reason, it is desired to maintain the activity of the entire granular sludge.

  In addition, if the activity of microorganisms in the upper part of the granular sludge bed is reduced in this way, the density and weakening of the sludge bed will be caused, and the biogas generated from the lower granular sludge and water flow will increase. In some cases, the granular sludge bed collapses or the upper granular sludge flows out to the subsequent stage, and the SS concentration of the treated water increases.

  This invention is made in order to solve such a subject, and it aims at providing the anaerobic processing apparatus which can reduce the SS density | concentration of treated water while maintaining the activity of the whole granular sludge. To do.

  The anaerobic treatment apparatus according to the present invention includes a granular sludge bed made of granular sludge in the lower part of the tank, introduces a liquid to be treated containing organic components from the lower part of the tank, and converts the liquid to be treated into granular sludge. An anaerobic treatment apparatus that performs an anaerobic treatment by flowing upward while making contact is characterized by comprising a collection input means for recovering sludge at the upper part of the granular sludge bed and introducing it into the lower part of the tank.

  According to such an anaerobic treatment apparatus, the liquid to be treated containing organic components flows upward from the bottom of the tank into the tank with respect to the granular sludge bed formed by the granular sludge formed in the lower part of the tank. Introduced, organic components are decomposed by granular sludge. Here, the sludge in the upper part of the sludge bed is recovered by the recovery input means and is input into the lower part of the tank, so that the dead bodies of microorganisms in the upper part of the sludge bed and the microorganisms with low activity are prevented from flowing out to the subsequent stage. The SS concentration of water can be reduced, and the dead bodies (organic matter) introduced into the lower part of the tank serve as microorganisms for the granular sludge bed, and the activity of the entire granular sludge can be maintained.

  Here, if the collection input means has a solubilization means for solubilizing the collected sludge before being introduced into the lower part of the tank, the dead carcass is easily eaten by the microorganisms in the tank by the solubilization. At the same time, microorganisms with low activity are considered to be easily eaten by microorganisms in the tank by solubilization, and as a result, the activity of the entire granular sludge can be further maintained and the SS concentration of treated water can be further reduced.

  Further, when the recovery charging means has an acid generation tank that organically oxidizes the sludge solubilized by the solubilizing means to the lower part of the tank, the organic acid is charged to the lower part of the tank. Therefore, anaerobic treatments such as methane fermentation can be performed efficiently.

  Here, it is preferable to include SS concentration detection means for detecting the SS concentration of treated water from the inside of the tank. When such a configuration is adopted, if the SS concentration of the treated water detected by the SS concentration detection means exceeds a predetermined SS concentration, the granular sludge bed collapses or the upper granular sludge flows out to the subsequent stage. Therefore, it is possible to control the drive of the collection and charging means, collect the sludge on the upper part of the sludge bed, and put it into the lower part of the tank. As a result, the activity of the entire granular sludge can be maintained and the SS concentration of treated water can be reduced.

  In addition, the liquid to be treated containing organic components is organic wastewater that is raw water, and preferably includes an organic matter concentration detecting means for detecting the organic matter concentration of the organic wastewater. When such a configuration is adopted, when the organic matter concentration of the organic wastewater detected by the organic matter concentration detecting means is less than the predetermined organic matter concentration, the organic matter concentration is a low-concentration wastewater with a low organic matter concentration. It can be judged that the number of dead microorganisms and microorganisms with low activity increase, and the drive of the collection and charging means can be controlled to collect the sludge in the upper part of the sludge bed and put it into the lower part of the tank. As a result, the activity of the entire granular sludge can be maintained and the SS concentration of treated water can be reduced.

  Thus, according to the present invention, it is possible to provide an anaerobic treatment apparatus capable of reducing the SS concentration of treated water and maintaining the activity of the entire granular sludge.

It is a schematic structure figure showing an anaerobic processing device concerning an embodiment of the present invention. It is a flowchart which shows the process sequence of the control means in FIG.

  Hereinafter, preferred embodiments of an anaerobic treatment apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an anaerobic processing apparatus according to an embodiment of the present invention, and FIG. 2 is a flowchart showing a processing procedure of a control means in FIG.

  As shown in FIG. 1, the anaerobic treatment apparatus 100 is an anaerobic treatment of organic waste water, and includes an anaerobic treatment tank (methane fermentation tank) 1 as a main component, and a front stage of the anaerobic treatment tank 1. The acid generation tank 2 is provided.

  The acid generation tank 2 is provided in the middle of the line L1 for introducing the organic wastewater as raw water into the anaerobic treatment tank 1, and organically oxidizes the organic wastewater to be a liquid to be treated suitable for methane fermentation. It is. The line L <b> 1 has a pump 3 for pumping the liquid to be processed in the acid generation tank 2 to the anaerobic treatment tank 1 at a position downstream from the acid generation tank 2.

  The anaerobic treatment tank 1 performs anaerobic treatment by introducing the liquid to be treated from the line L1 from the lower part of the tank 1 through the introduction pipe 4, and is here a UASB type tank. Here, the tank 1 has a shape in which the upper and lower ends of the cylinder are closed, and a granular sludge bed G made of granular microbial sludge is formed in the lower part of the tank 1.

  Above the granular sludge bed G in the tank 1, three-phase separation for separating biogas containing methane generated by anaerobic treatment (methane fermentation process), granular sludge, and treated water in the tank 1 Part 5 is provided.

  Connected to the upper part of the tank 1 is a line L2 for discharging the treated water separated in the three-phase separation unit 5 to the subsequent stage, and a line for returning a part of the treated water to the acid generation tank 2. L3 is connected.

  In particular, in the present embodiment, there is provided recovery input means 6 for recovering the sludge on the upper part of the granular sludge bed G in the tank 1 and putting it in the lower part of the tank 1.

  The recovery charging means 6 includes a line L4 for recovering sludge on the upper part of the granular sludge bed G, and a line L5 for supplying the recovered sludge connected to the line L4 to the lower part in the tank 1.

  The line L4 has a discharge pipe 7 for entering the tank 1 and discharging the sludge on the upper part of the granular sludge bed G on the upstream side of the line L4, and the granule through the discharge pipe 7 outside the tank 1 of the line L4. A pump 8 for pumping the sludge on the upper part of the sludge bed G downstream is provided. Here, the downstream end of the line L4 is configured to join the upstream position of the acid generation tank 2 of the line L1. Accordingly, the line for connecting the collected sludge connected to the line L4 to the lower part of the tank 1 Here, L5 is shared with the downstream side of the line L1.

  Further, a solubilizing device (solubilizing means) 9 is provided downstream of the pump 8 in the line L4. This solubilizer 9 solubilizes the recovered sludge by, for example, alkali treatment.

  As described above, the recovery charging means 6 of the present embodiment is configured to include the line L4 having the pump 8, the solubilizer 9, the acid generation tank 2, and the line L5 having the pump 3.

  Further, in the anaerobic treatment apparatus 100 of the present embodiment, an SS concentration detection sensor (SS concentration detection means) 10 that detects the SS concentration of treated water is disposed in a line L2 that discharges treated water to the subsequent stage. In addition, an organic substance concentration detection sensor (organic substance concentration detecting means) 11 for detecting the organic substance concentration of the organic waste water is disposed in the line L1 for introducing the organic waste water.

  Furthermore, the anaerobic treatment apparatus 100 of the present embodiment is a control means (CPU) that controls the drive of the pump 8 that constitutes the collection input means 6 based on the outputs of the SS concentration detection sensor 10 and the organic matter concentration detection sensor 11. ) 12 and a RAM for storing information such as threshold values T1 and T2, which will be described later, and a ROM for storing the processing procedure of the control means 12 in the form of a program.

  According to the anaerobic treatment apparatus 100 having such a configuration, when the organic wastewater is introduced into the acid generation tank 2, the organic components in the organic wastewater are caused by the acid producing bacteria accommodated in the acid generation tank 2. It is decomposed to produce lower fatty acids such as acetic acid, propionic acid and butyric acid. The liquid to be treated containing the lower fatty acid is introduced from the lower part in the tank 1 and flows upward in the tank 1 so that the liquid to be treated and the granular sludge efficiently come in countercurrent contact. Thereby, the lower fatty acid contained in the liquid to be treated is decomposed by the microorganisms, and biogas containing methane is generated. The biogas is separated by the three-phase separation unit 5 and collected from the upper part of the tank 1, and the treated water is discharged to the subsequent stage through the line L2, and a part of the treated water is prevented from flowing out of the acid producing bacteria and the acid producing tank 2 From the viewpoint of dilution of the organic waste water inside, it is returned to the acid generation tank 2 through the line L3.

  In parallel with the above operation, the following processing procedure by the control means 12 is executed. This processing procedure will be described with reference to the flowchart shown in FIG.

  First, in step 1 (S1), the SS concentration of treated water is compared with the threshold value T1, and when SS concentration ≧ T1, it is caused by the dead bodies of microorganisms above the granular sludge bed G or the microorganisms with low activity. Therefore, it is determined that the granule is collapsed or the granule sludge is discharged to the subsequent stage, and the process proceeds to step 2. In step 2, the pump 8 is driven and the sludge on the upper part of the granule sludge bed G, that is, the microorganisms Collect dead bodies and low activity microorganisms.

  The recovered granular sludge is solubilized by the solubilizer 9 and supplied to the organic wastewater, so that the organic matter concentration of the organic wastewater is increased. The organic waste water with the increased organic matter concentration is introduced into the acid generation tank 2, converted into a lower fatty acid that promotes anaerobic treatment, and introduced into the lower part of the tank 1. That is, in addition to the feed in the organic waste water, the sludge on the upper part of the granular sludge bed G is fed into the lower part of the tank 1 as feed.

  On the other hand, in step 1, when SS concentration <T1, it is judged that the granule in the tank 1 has not collapsed or the granule sludge has flowed to the subsequent stage, and the process proceeds to step 3. If the organic matter concentration of the wastewater is compared with the threshold value T2, if the organic matter concentration <T2, the organic matter concentration is low and the wastewater is low concentration. Judgment proceeds to step 2, and in step 2, the sludge is recovered at the upper part of the granule sludge bed G by the recovery input means 6 to increase the organic matter concentration of the organic wastewater, and in addition to the feed in the organic wastewater. Then, the upper part of the granular sludge bed G is fed into the lower part of the tank 1 as food.

  On the other hand, in Step 3, when the organic matter concentration ≧ T2, the organic matter concentration of the organic waste water is high, and the flow is terminated on the assumption that the activity of the entire granular sludge in the tank 1 can be maintained.

  Thus, in the present embodiment, the sludge on the upper part of the granular sludge bed G is recovered by the recovery charging means 6 and is input to the lower part of the tank 1. It is possible to prevent dead bodies and microorganisms with low activity from flowing out to the subsequent stage, reduce the SS concentration of treated water, and the organic matter (organic components) introduced into the lower part of the tank 1 is the microorganism feed of the granular sludge bed G. Thus, the activity of the entire granule sludge can be maintained.

  In addition, since the recovery charging means 6 has a solubilizing device 9 that solubilizes the recovered sludge before charging it into the lower part of the tank 1, the dead bodies of microorganisms are eaten by the microorganisms in the tank 1 by solubilization. In addition, the microorganisms in the tank 1 can be easily eaten by solubilization of microorganisms with low activity, and as a result, the activity of the entire granular sludge can be further maintained and the SS concentration of the treated water can be further reduced.

  Moreover, since the collection | recovery injection | throwing-in means 6 has the acid production tank 2 which organically oxidizes before throwing the sludge solubilized with the solubilizer 9 in the lower part in the tank 1, an organic acid is in the tank 1. It will be put into the lower part, and anaerobic processing can be performed efficiently.

  In this case, the solubilizer 9 and the acid generator tank 2 are provided as being particularly preferable, but the solubilizer 9 and the acid generator tank 2 may be omitted. In this case, recovery of the sludge on the upper part of the granular sludge bed G prevents the microbial dead bodies on the upper part of the granule sludge bed G from flowing out to the rear stage of the microorganisms with low activity, thereby reducing the SS concentration of the treated water. This can be done in the same way as described above, and since the recovered dead bodies and low-activity microorganisms are introduced into the lower part of the tank 1, the organic dead bodies are fed into the microorganisms in the tank 1 (possible It is possible to maintain the activity of the entire granular sludge.

  As described above, the present invention has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment. For example, in the above embodiment, the solubilizer 9 is provided as being particularly preferable. However, the solubilizer 9 can be replaced with a pulverizing means for pulverizing the granular sludge with, for example, a mill. By using such a pulverizing means, it is easy to eat dead bodies of microorganisms.

  Moreover, in the said embodiment, although determination of both step 1 and step 2 is performed, only one determination may be sufficient.

  Further, in the above embodiment, the control means 12 automatically controls, but it is also possible to control the driving of the pump 8 and the like with human intervention.

  Moreover, in the said embodiment, although the anaerobic processing apparatus 100 is made into the UASB type anaerobic processing apparatus, the to-be-processed liquid which contains an organic component by further promoting the granulation of the granular sludge bed G and expanding it. Of course, it can also be applied to an EGSB (Expanded Granular Sludge Bed) treatment device designed to improve the contact efficiency with the tank. The present invention can be applied to an anaerobic treatment apparatus that introduces a liquid to be treated containing an organic component from the lower part of the tank 1 and causes the liquid to be treated to flow upward while being in contact with the granular sludge.

  DESCRIPTION OF SYMBOLS 1 ... Anaerobic processing tank, 2 ... Acid production tank, 6 ... Collection | recovery input means, 9 ... Solubilizer (solubilization means), 10 ... SS concentration detection sensor (SS concentration detection means), 11 ... Organic substance concentration detection sensor ( Organic substance concentration detecting means) 100 ... anaerobic treatment device, G ... granule sludge bed.

Claims (5)

A granule sludge bed made of granular sludge is provided in the lower part of the tank, a liquid to be treated containing organic components is introduced from the lower part of the tank, and the liquid to be treated flows upward while being in contact with the granule sludge. In an anaerobic processing device that performs anaerobic processing by
It has a recovery input means for recovering the sludge on the upper part of the granular sludge bed and putting it in the lower part of the tank ,
The anaerobic treatment apparatus characterized in that the recovery charging means has a solubilizing means for solubilizing the recovered sludge before being charged into the lower part of the tank . 2. The anaerobic treatment apparatus according to claim 1 , wherein the solubilizing means solubilizes the sludge collected by the collecting and charging means so as to be easy to eat microorganisms in the granular sludge bed .   The anaerobic treatment apparatus according to claim 2, wherein the recovery charging means includes an acid generation tank that organically oxidizes the sludge solubilized by the solubilizing means before being charged into the lower portion of the tank.   The anaerobic treatment apparatus according to any one of claims 1 to 3, further comprising SS concentration detection means for detecting the SS concentration of treated water from the tank. The liquid to be treated containing the organic component is an organic waste water that becomes raw water,
The anaerobic treatment apparatus according to any one of claims 1 to 4, further comprising an organic substance concentration detection unit that detects an organic substance concentration of the organic waste water.

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