KR100546991B1 - Organic wastewater treatment method and apparatus - Google Patents

Abstract

The present invention relates to a method and apparatus for treating organic wastewater discharged from manufacturing processes such as sewage, manure, food factories, and chemical plants by biodigestion, which can greatly reduce the amount of surplus sludge discharged out of the treatment system. Another object of the present invention is to provide a method and apparatus for treating organic wastewater in which the nitrogen-containing organic component or the nitrogen-containing inorganic component in the treated water discharged to the outside of the treatment system is reduced. The method for treating organic wastewater according to the present invention is characterized by solubilizing sludge generated by nitriding and denitrification after nitrifying and denitrifying the organic wastewater. Further, the apparatus for treating organic wastewater according to the present invention is characterized by comprising means for nitriding and denitrifying organic wastewater and for solubilizing sludge generated by nitriding and denitrification.

Description

Organic Wastewater Treatment Method and Apparatus {ORGANIC WASTEWATER TREATMENT METHOD AND APPARATUS}

The present invention relates to a method and apparatus for treating organic wastewater discharged from manufacturing processes such as wastewater containing organic substances, such as sewage, manure, food plants, chemical plants, etc. by biodigestion.

Conventionally, a method of treating organic wastewater of this kind is a method of biodigesting organic components of organic sludge by aerobic or anaerobic microbial decomposition such as an aerobic digestion method called anaerobic digestion method or anaerobic methacation method. It is adopted. In this method, the treatment liquid is appropriately separated by treating the organic matter with gaseous components such as carbon dioxide gas and methane gas, and separating the treated sludge containing surplus sludge composed of microbial biomass and untreated residual sludge produced by biodigestion in a precipitation tank or the like. On the other hand, surplus sludge is usually treated by ocean dumping or landfilling.

However, dumping in the ocean also leads to environmental destruction, so it is almost banned now that global environmental protection is an issue. In landfills, landfill disposal is becoming more difficult year after year.

Therefore, the patent applicant of the present invention is a method for reducing the amount of surplus sludge generated by the biological treatment of organic wastewater, and has applied for a patent as an invention described in JP-A-9-10791.

According to the present invention, after the organic waste liquid sent from the organic waste liquid storage device is subjected to aerobic biotreatment in the aeration apparatus, the treated liquid is solid-liquid separated into the treated water and sludge in the solid-liquid separator, and a part of the sludge separated in the solid-liquid separator is separated. It is a method of conveying to the aeration apparatus, heat-exchanging the sludge among the sludge separated by the solid-liquid separator, and solubilizing it at high temperature with a solubilizer, and conveying the solubilized process liquid to the aeration apparatus.

However, since sludge produced by biological treatment generally contains protein, there is a problem that nitrogen compounds such as ammonia of the liquid returned from the solubilizer to the aerator are released to the outside together with the treated water discharged from the solid-liquid separator. have. In addition, since sludge produced by biological treatment generally contains a phosphorus component, there is a problem that the phosphorus compound of the liquid returned from the solubilizer to the aeration apparatus is discharged to the outside together with the treated water discharged from the solid-liquid separator.

SUMMARY OF THE INVENTION The present invention has been made to solve this problem, and it is possible to greatly reduce the amount of surplus sludge discharged out of the treatment system, and to reduce the amount of organic wastewater containing nitrogen or inorganic nitrogen in the treated water discharged out of the treatment system. It is an object to provide a treatment method and an apparatus thereof.

In order to achieve the above object, the present invention is a method for biologically treating organic wastewater, and the organic wastewater is solubilized sludge generated by nitriding and denitrification after the organic wastewater is nitrified and denitrified. It is to provide a method for treating wastewater.

The present invention also provides an apparatus for biologically treating organic wastewater, comprising a means for nitriding and denitrifying organic wastewater and a solubilizing tank for solubilizing sludge generated by nitriding and denitrification.

As described above, the present invention can nitrify and denitrify organic wastewater, solubilize sludge generated by nitriding and denitrification, so that sludge produced by nitriding and denitrification can be reduced, and the treatment discharged out of the treatment system. There is an effect that the nitrogen-containing organic powder and the nitrogen-containing inorganic powder in the water can be greatly reduced as compared with the prior art.

Nitrification and denitrification of the organic wastewater is carried out batchwise, for example in a reactor.

In this case, the nitriding treatment is performed by, for example, aeration, and denitrification is performed by stopping the aeration. It is preferable to carry out solubilizing liquid to a reaction tank 3 hours-30 minutes before stopping aeration, and it is more preferable to carry out 1 hour-30 minutes ago.

In this way, when nitriding and denitrification are carried out in a batch including a nitriding process by aeration, and the solubilization liquid is returned to the reaction tank before a predetermined time to stop the aeration, the organic matter contained in the solubilized sludge is denitrated. It can be effectively used as a proton source (BOD source) of to promote denitrification. Therefore, there is an effect that the amount of chemicals such as methanol commonly used as the proton source can be reduced, and the cost according to the amount of chemicals can be reduced.

In addition, another aspect of nitriding and denitrification of organic wastewater is carried out by an anaerobic treatment process, a primary aeration process, a denitrification process in an anoxic tank, and a secondary aeration process. In this case, the solid-liquid separated sludge is solubilized after a secondary aeration process.

In addition, another aspect of nitriding and denitrification of organic wastewater is carried out by a denitrification step in an anaerobic tank, an anaerobic treatment step, a treatment step in a compatible tank, a denitrification step in an oxygen free tank, and an aeration step. In this case, the sludge separated by solid-liquid separation after the aeration process is solubilized. In addition, nitriding is performed in an aeration process, and the nitriding liquid after nitriding is returned to a denitrification process.

In addition, another aspect of nitriding and denitrification of organic wastewater is carried out by an anaerobic treatment step, a denitrification step in an oxygen-free tank, and an aeration step, and at the same time, reduces dissolved oxygen in the treatment liquid after solubilization treatment. Also in this case, nitriding is carried out in the aeration process. The nitriding liquid after nitriding is returned to the denitrification process.

In addition, another aspect of nitriding and denitrification of organic wastewater is carried out by an anaerobic treatment step, a denitrification step in an anoxic tank, and an aeration step.

When these nitriding and denitrification treatments include aerobic treatment processes such as anaerobic treatment and aeration treatment, even when phosphorus is contained in sludge generated in nitrification and denitrification treatment, phosphorus is released from anaerobic treatment and aerobic treatment. Phosphorus is introduced.

Another object of the present invention is to provide a method and an apparatus for treating organic wastewater in which phosphorus components in the treated water discharged out of the treatment system decrease.

In order to achieve the above object, the present invention provides a method and apparatus for treating organic wastewater provided with a means for removing phosphorus in sludge generated by nitriding and denitrification as described above. By forming such a phosphorus removing means, it is possible to appropriately prevent the phosphorus component from being discharged out of the system.

1 is a schematic block diagram showing an apparatus for treating organic wastewater as one embodiment.

FIG. 2 is a block diagram of a batch processing step performed in the processing apparatus of FIG. 1.

3 is a block diagram of another example of a batch processing step performed in the processing apparatus of FIG. 1.

4 is a schematic block diagram showing an apparatus for treating organic wastewater in another embodiment.

5 is a schematic block diagram showing an apparatus for treating organic wastewater according to another embodiment.

6 is a schematic block diagram showing an apparatus for treating organic wastewater in another embodiment.

7 is a schematic block diagram showing an apparatus for treating organic wastewater according to another embodiment.

8 is a schematic block diagram showing an apparatus for treating organic wastewater in another embodiment.

9 is a schematic block diagram showing an apparatus for treating organic wastewater in another embodiment.

10 is a schematic block diagram showing an apparatus for treating organic wastewater in another embodiment.

11 is a schematic block diagram showing an apparatus for treating organic wastewater in another embodiment.

12 is a schematic block diagram showing an apparatus for treating organic wastewater in another embodiment.

FIG. 13 is a schematic block diagram showing an apparatus for treating organic wastewater in another embodiment. FIG.

14 is a schematic block diagram showing an apparatus for treating organic wastewater in another embodiment.

FIG. 15 is a schematic block diagram showing an apparatus for treating organic wastewater in another embodiment. FIG.

FIG. 16 is a block diagram of a batch processing step performed in the processing apparatus of FIG. 15.

17 is a schematic block diagram showing an apparatus for treating organic wastewater in another embodiment.

18 is a schematic block diagram showing an apparatus for treating organic wastewater in another embodiment.

Best Mode for Carrying Out the Invention

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described according to drawing.

(Embodiment 1)

The apparatus for treating organic wastewater of the present embodiment is composed of a reaction tank 1 and a solubilization tank 2 as shown in FIG. 1. In the reactor 1, the organic wastewater is treated in a batchwise manner. Sewage was used in this embodiment as organic wastewater which is raw water.

In this embodiment, the treatment is carried out with the inflow, reaction, precipitation, drainage, sludge discharge, and the like of raw water as one cycle. More specifically, as shown in FIG. 2, the processes of aeration, stirring, aeration, agitation, aeration, sedimentation by stopping aeration, solid-liquid separation, and solubilization are circulated during the inflow and reception of raw water. In this case, aeration is an aerobic treatment and agitation is an anaerobic treatment. The repetition process of aeration and stirring, the process of precipitation, and solid-liquid separation are performed in the reaction tank (1), and the solubilization process is performed in the solubilization tank (2). Batch treatment of a series of wastewater treatments of treatment water discharge from inflow of raw water can be adjusted for each process so as to be carried out a plurality of times (for example, 2 to 4 times) per day, but depending on the nature and quantity of wastewater, etc. The treatment time of each process may be adjusted to carry out batch treatment once a day or twice a three days.

In the present embodiment, nitriding treatment with nitride bacteria is performed in the aeration process, and denitrification treatment with denitrification bacteria is performed in the stirring process in which the aeration is stopped. Thereafter, the sludge is settled and separated by the aeration stop. The supernatant is discharged or the like, and a portion of the settled sludge is kept in the reactor 1 for the next batch treatment, and the remaining part of the sludge is supplied to the solubilization tank 2 and solubilized. It is preferable that the liquid solubilized by the solubilization tank 2 is conveyed to a 1st step stirring process, as shown in FIG. In addition, in a nitriding process, in order to maintain nitriding reaction by nitride bacteria, it is preferable to make pH 7 or more, and it is especially preferable to set it as pH 7.0-8.0. Moreover, it is preferable to set it as 15 degreeC-35 degreeC, and it is more preferable to set it as 25 degreeC-35 degreeC.

The solubilization treatment liquid is returned to the reaction tank 1 3 hours to 30 minutes before the first stage aeration is stopped, preferably 1 hour to 30 minutes. The number of cycles is determined by the BOD-SS load of the reactor. Generally, in the case of high load operation (BOD-SS load: 0.2-0.4 kg BOD / kgSS * work), it is preferable that the nitriding denitrification cycle of aeration and stirring is operated by 3 to 4 cycles. Moreover, in the case of low load operation (BOD-SS load: 0.03-0.05 kg BOD / kgSS * work), it is preferable that a nitriding denitrification process cycle is operated by 2-3 cycles.

The solubilization tank 2 is for solubilizing the sludge supplied from the reaction tank 1 as mentioned above, and this solubilization is performed by solubilizing enzymes, such as a protease. This solubilizing enzyme is produced by aerobic thermophiles such as bacteria of the genus Bacillus. Such thermophilic bacteria may be retained in the solubilization tank 2 in advance, contained in the sludge supplied to the solubilization tank 2, or may be newly added in the solubilization tank 2.

As Bacillus bacteria, for example, Bacillus stearothermophilus, Bacillus thermoleovorans and the like can be used, and in particular, Bacillus SPT2-1 [FERM P-15395], Bacillus SPT3 [FERM PT] -19226], Geobacillus SPT4 [FERM P-08452], Geobacillus SPT5 [FERM P-08453], Geobacillus SPT6 [FERM P-08454], Geobacillus SPT7 [FERM P-08455], and the like. It is preferable.

In the solubilization tank (2), the sludge is decomposed by thermophilic bacteria, but ozone decomposition, electrolysis, thermal alkali decomposition, enzymatic decomposition (for example, protease, lipase, glycosidase, etc. are added alone or in combination), etc. It may also be performed in combination with various conventionally known methods.

In the solubilization tank (2), organic sludge is solubilized anaerobicly or aerobically at a biologically high temperature condition. In this case, the inoculating cells (thermobacteria) of anaerobic or aerobic microorganisms used under high temperature conditions are obtained by culturing the microorganisms, for example, from a conventional anaerobic or aerobic digester. In addition, the optimum temperature of the solubilization tank 2 is preferably operated under the conditions of the temperature range of 50 to 90 ° C, but is different depending on the type of thermophilic bacteria that decomposes the organic solids contained in the sludge that is the high temperature treatment target. For example, in case of thermophilic bacteria isolated from sewage surplus sludge, the temperature under high temperature conditions is 55-75 ° C so that both the solubilization reaction by microorganisms (thermococcus) and the physicochemical pyrolysis by heat can occur efficiently and efficiently at the same time. It is set in the range of preferably 60-70 degreeC.

As a result, it is preferable to set the temperature in the range of 50 to 90 ° C. according to the type of microorganism so that both the solubilization reaction by microorganisms (thermobacteria) and the physicochemical thermal decomposition by heat can be efficiently and sufficiently produced simultaneously. . In particular, when using Bacillus genus bacteria which are aerobic thermophilic bacteria, it is preferable to set in the temperature range of 55-70 degreeC, and especially the range of 60-65 degreeC is more preferable. Moreover, when using the genus Bacillus genus bacteria which are aerobic thermophilic bacteria, it is preferable to set in 55-65 degreeC temperature range.

Moreover, pH is set so that it may become a range of pH 6-9, preferably 7-8 according to the kind of microorganism. This is to prevent the solubilization treatment liquid from adversely affecting nitriding or denitrification. The solubilization treatment is preferably an aerobic treatment in order to decompose (nitrify) the ammonia produced by the decomposition of sludge to some extent.

In this embodiment, solubilization sludge is returned to the reaction tank in a 1st (first) aeration process process 3 hours-30 minutes ago, Preferably 1 hour-30 minutes, before stopping aeration process. Thereby, denitrification can be promoted by effectively using the organic substance contained in the solubilized sludge as a proton source (BOD source) in the denitrification process. Therefore, the chemical amount, such as methanol generally used as a proton source, can be reduced, and the cost according to the chemical amount can be reduced.

In this case, the solubilization treatment time is preferably 12 to 72 hours, more preferably 18 to 48 hours, and most preferably 20 to 36 hours. In addition, since the solubilization time is set by the wastewater treatment system which carries out nitriding and denitrification of wastewater, and a sludge solubilization method, it demonstrates for every embodiment after that.

In addition, ammonia is generated by the solubilization of sludge by thermophilic bacteria, and the ammonia contained in the solubilized sludge is oxidized to nitrogen nitrite or nitrogen nitrate which can be denitrified in the aeration process. As a result, denitrification is properly performed, and harmful nitrogen components are not released out of the system.

In this embodiment, it is important to oxidize ammonia to nitrous acid or nitric acid while the organic matter remains in the aeration process, so that the timing and solubilization time of the solubilized sludge returned to the reaction tank in the first aeration process are important.

(Embodiment 2)

This embodiment is a batch treatment method similarly to the first embodiment, in which the treatment device is composed of a reaction tank 1 and a solubilization tank 2, and aeration, agitation, aeration, agitation, aeration during inflow and reception of raw water. Is common to the first embodiment in that the processes of precipitation, solid-liquid separation, and solubilization by circulation stop are circulated. Therefore, also in this embodiment, the nitriding process by nitride bacteria is performed in an aeration process, and the denitrification process by denitrification bacteria is performed in the stirring process which stopped aeration.

However, in this embodiment, as shown in FIG. 3, the process liquid after solubilization process is conveyed by a 1st (first) stirring process, and differs from the case of Embodiment 1 conveyed by an aeration process in this point.

Also in this embodiment, since the solubilization liquid is returned to the reaction tank 1 in a denitration process, the organic substance contained in a solubilization liquid is effectively used as a proton source at the time of denitrification, and denitrification is accelerated | stimulated. In this case, in order to reduce the ammonia contained in the solubilized sludge, it is preferable to oxidize with nitrogen nitrite or nitrogen nitrate which can be denitrified in the solubilization treatment. Specifically, it is considered that the solubilization treatment time is longer than that in the first embodiment. -72 hours are preferable and 36-72 hours are more preferable.

In particular, in this embodiment, since the organic substance as a proton source is directly returned to a denitrification process, the quantity of chemicals, such as methanol generally used, can be reduced, and the cost according to the chemical quantity can be reduced. As described above, by combining sludge solubilization treatment with nitrification and denitrification of wastewater, and optimally setting the conditions of each treatment process when combined, the amount of surplus sludge can be greatly reduced and the quality of treated water There is an effect that can be maintained well.

As microorganisms for producing solubilizing enzymes for solubilizing sludge, it is preferable to use thermophilic bacteria, in particular, various Bacillus bacteria or Geobacilli bacteria.

The temperature at the time of solubilization is preferably in the range of 50 to 90 ° C. as in Embodiment 1, and preferably in the range of 55 to 70 ° C. when using aerobic thermophiles such as Bacillus bacteria. And especially the range of 60-65 degreeC is more preferable. Moreover, the pH at the time of solubilization process is also set to become the range of pH 6-9, Preferably it is the range of 7-8 similarly to Embodiment 1.

In addition, the temperature, pH, etc. of a nitriding process are also the same as that of Embodiment 1.

(Embodiment 3)

As shown in FIG. 4, the apparatus for treating organic wastewater of the present embodiment includes a fermentation broth 3, an anaerobic tank 4, a primary aeration tank 5, an anaerobic tank 6, a secondary aeration tank 7, and a precipitation tank 8. , And a solubilization tank 2. As a to-be-processed liquid stored in the fermentation liquid storage tank 3, in this embodiment, the acid fermentation liquid which carried out the gas decomposition (methane fermentation) of the residue discharged | emitted from a food factory etc. is used. Apart from the liquid to be treated, sewage and the like are supplied to the anaerobic tank.

The anaerobic tank 4 anaerobicly digests the sewage and acid fermentation liquid supplied from the fermentation broth 1 and releases phosphorus in the sludge into the liquid when the sludge is contained in the return sludge or the acid fermentation liquid. It has a function.

The primary aeration tank 5 is subjected to aerobic biotreatment of the anaerobic treatment liquid in the anaerobic tank 4 by aeration agitation, to oxidatively decompose organic matter in the anaerobic treatment water, or to nitrify inflow ammonia. It is for. This primary aeration tank 5 should just be equipped with an aeration means, and the aeration means is not limited, For example, an diffuser etc. can be used. The aeration treatment is preferably carried out at room temperature with an aeration amount of preferably 0.1 to 0.5 vvm so as to allow aerobic nitrification, but depending on the load, the aeration treatment may be performed at a higher temperature with an aeration amount exceeding this. The liquid to be treated is preferably adjusted to pH 5.0 to 8.0, more preferably to pH 7.0 to 8.0.

The oxygen-free tank 6 is for denitrifying the treatment liquid exhaled in the primary aeration tank 5.

The secondary aeration tank 7 is for aerobic biotreatment of the treatment liquid denitrified in the anoxic tank 6. In this secondary aeration tank 7, it is comprised similarly to the said primary aeration tank 3, and similarly, biological treatment is performed by aeration stirring. The secondary aeration tank 7 in this case has both functions of nitriding and BOD removal. Although a part of the nitride liquid which is the treatment liquid in the secondary aeration tank 7 is not shown in figure, it is conveyed to the anoxic tank 6, and nitric acid or nitrous acid in a nitriding liquid denitrates.

The sedimentation tank 8 is for solid-liquid separation of the treatment liquid biologically treated in the secondary aeration tank 7, wherein the separated liquid fraction is reused or discharged as the treatment liquid, and a part of the sludge that is the separated and precipitated solid is solubilized next. While being supplied to the tank 2, the remaining part is returned to the anaerobic tank 4.

Next, embodiment of the processing method which processes both the residue discharged | emitted from sewage, a food factory, etc. by the processing apparatus which consists of the above structures is demonstrated.

First, the residue discharged from a food factory or the like is gas decomposed. This gaseous decomposition takes place, for example, by acid and methane fermentation. An acid fermentation liquor is obtained by such gas decomposition, and the acid fermentation liquor is stored in the fermentation broth 3. The acid fermentation liquid is supplied to the anaerobic tank 4 from this fermentation broth 3. Sewage is also supplied to the anaerobic tank (4).

Then, the treated water after the anaerobic treatment is supplied to the first aeration tank 5 which is the next step, and is treated aerobicly while being aerated and agitated. Nitriding treatment is performed by aerobic treatment by the aeration stirring.

Next, the treatment liquid aerated in the primary aeration tank 5 is supplied to the oxygen-free tank 6. In this oxygen-free tank 6, denitrification is performed.

In addition, an acid fermentation liquid is supplied from the fermentation broth 3 to the anoxic tank 6. This is for the acid fermentation liquid to be effectively used as a proton source (BOD source) in denitrification to promote denitrification.

The treatment liquid denitrified in the oxygen-free tank 6 is supplied to the secondary aeration tank 7 and is treated aerobicly with aeration stirring. Nitriding is performed by the aeration treatment in the secondary aeration tank 7 and BOD removal is performed.

Subsequently, the treatment liquid aerated in the secondary aeration tank 7 is supplied to the settling tank 8. In this sedimentation tank (8), solid-liquid separation is carried out, and the separated liquid fraction is reused or discharged as a treatment liquid, and a part of sludge which is separated and precipitated solid is supplied to the solubilization tank (2) and aerobically by thermophilic bacteria. Sludge is solubilized.

The remaining portion of the precipitated sludge is returned to the anaerobic tank 4 as sludge.

The sludge solubilized in the solubilization tank 2 is returned to the anoxic tank 6 and processed again. The denitrification treatment in the oxygen-free tank 6, the aeration treatment in the secondary aeration tank 7, the solid-liquid separation in the precipitation tank 8, and the solubilization treatment in the solubilization tank 2 are circulated repeatedly.

In this embodiment, the sludge is solubilized continuously instead of in the same batch as in the first embodiment. When the solubilization of the sludge is continuously performed in this way, the HRT furniture is based on the amount of inflow liquid and the effective capacity of the reactor. Become. That is, HRT can be calculated based on the formula of HRT (hydraulic residence time) = V / Q (V: reactor capacity, Q: influent liquid amount).

As long as solubilization is achieved to the desired degree, of course, the shorter the HRT, the smaller the volume of the reactor. Therefore, the redundant solubilization process is avoided by determining the solubilization time based on the HRT.

It is preferable to select HRT based on HRT in which the production and secretion of thermophilic bacteria are maximized. By setting the HRT in this way, the reaction by the generated and secreted sludge solubilizing enzyme can be efficiently utilized. Usually, it is preferable to set HRT to 12 to 72 hours, and from the viewpoint of oxidizing ammonia in the solubilizing liquid, it is more preferable to set it to 24 to 72 hours, and to maintain both the compactness of the solubilizing device and the improvement of the treated water quality. It is most preferable to set from 36 to 48 hours from a viewpoint.

In addition, HRT of tanks other than the solubilization tank (2) is 0.5 to 1.5 hours in the anaerobic tank (4), 2 to 6 hours in the primary aeration tank (5), 0.5 to 3 hours in the oxygen-free tank (6), and secondary aeration tank (7). 0.5 to 2 hours, preferably 0.5 to 1 hour in the anaerobic tank (4), 3 to 5 hours in the primary aeration tank (5), 1 to 2 hours in the anaerobic tank (6), 0.5 to 2 hours in the secondary aeration tank (7) 1.5 hours.

As microorganisms for producing solubilizing enzymes for solubilizing sludge, it is preferable to use thermophilic bacteria, in particular, various Bacillus bacteria or Geobacilli bacteria.

The temperature at the time of solubilization is preferably in the range of 50 to 90 ° C. as in Embodiment 1, and preferably in the range of 55 to 70 ° C. when using aerobic thermophiles such as Bacillus bacteria. And especially the range of 60-65 degreeC is more preferable. Moreover, the pH at the time of solubilization process is also set to become the range of pH 6-9, Preferably it is the range of 7-8 similarly to Embodiment 1.

In addition, the temperature, pH, etc. of a nitriding process are also the same as that of Embodiment 1.

(Embodiment 4)

In this embodiment, as shown in FIG. 5, the concentrator 9 is formed between the settling tank 8 and the solubilization tank 2, ie, in the flow path from the settling tank 8 to the solubilization tank 2.

In this embodiment, the sludge separated by the settling tank 8 is supplied to the concentrator 9. In the concentrator 9, the sludge is concentrated, for example, by gravity settling. In addition to gravity sedimentation, flotation, evaporation, membrane concentration, flocculant addition, drum screen-type concentration, or centrifugal force may be employed. It is preferable to concentrate the sludge concentration up to 99% by weight or less (sludge concentration of 1% by weight or more) from the viewpoint of improving the solubilization rate of sludge by thermophilic bacteria and compactizing the solubilization tank. The concentrated liquid after concentration is supplied to the solubilization tank 2. However, it is preferable that sludge concentration does not exceed 5 weight%. This is because if it exceeds 5% by weight, it is difficult to feed the pump, and the foaming of the sludge due to the aerobic treatment in the solubilization tank becomes remarkable.

Anaerobic treatment in anaerobic tank (4), aeration in primary aeration tank (5), denitrification in anoxic tank (6), aeration in secondary aeration tank (7), solid-liquid separation in soaking tank (8), solubilization Since the solubilization treatment in the tank (2) is the same as that in the third embodiment, the description thereof is omitted.

As microorganisms for producing solubilizing enzymes for solubilizing sludge, it is preferable to use thermophilic bacteria, in particular, various Bacillus bacteria or Geobacilli bacteria.

The temperature at the time of solubilization is preferably in the range of 50 to 90 ° C. as in Embodiment 1, and preferably in the range of 55 to 70 ° C. when using aerobic thermophiles such as Bacillus bacteria. And especially the range of 60-65 degreeC is more preferable. Moreover, the pH at the time of solubilization process is also set to become the range of pH 6-9, Preferably it is the range of 7-8 similarly to Embodiment 1.

(Embodiment 5)

In this embodiment, as shown in FIG. 6, the nitriding tank 10 is formed in the conveyance flow path between the solubilization tank 2 and the oxygen-free tank 6, ie, from the solubilization tank 2 to the oxygen-free tank 6. By forming such a nitriding tank 10, ammonia contained in the sludge solubilizing liquid is changed into nitrous acid and nitric acid.

In addition, in this embodiment, a part of sludge is returned from the settling tank 8 to the anaerobic tank 4, and the remaining sludge is also supplied to the nitriding tank 10 via the solubilization tank 2. As shown in FIG.

The HRT of the solubilization tank in the present embodiment is preferably selected based on the HRT in which the generation and secretion amount of sludge solubilizing enzyme from which thermophilic bacteria are secreted is maximized. By setting the HRT in this way, the reaction by the generated and secreted sludge solubilizing enzyme can be efficiently utilized. Usually, the HRT is set to 12 to 72 hours. However, in this embodiment, since the nitriding tank 10 is located at the rear end of the solubilizing tank, the solubilizing solution can be introduced into the nitriding tank 10 while ammonia remains in the solubilizing solution. In consideration of this, it is more preferable to set the HRT to 18 to 48 hours, and most preferably to 20 to 36 hours.

Moreover, the operating conditions of the nitriding tank 10 are 25-35 degreeC, and pH is preferable in the range of 7.0-8.0. The HRT of the nitriding tank 10 is 30 minutes to take into consideration that the ammonia contained in the sludge solubilizing solution is oxidized to nitrous acid or nitric acid, and that the organic material serving as the proton source for the denitrification treatment, which is the next step, needs to remain. It is preferable to set it as 3 hours.

Anaerobic treatment in anaerobic tank (4), aeration in primary aeration tank (5), denitrification in anoxic tank (6), aeration in secondary aeration tank (7), solid-liquid separation in soaking tank (8), solubilization Since the solubilization treatment in the tank (2) is the same as that in the third embodiment, the description thereof is omitted.

As microorganisms for producing solubilizing enzymes for solubilizing sludge, it is preferable to use thermophilic bacteria, in particular, various Bacillus bacteria or Geobacilli bacteria.

The temperature at the time of solubilization is preferably in the range of 50 to 90 ° C. as in Embodiment 1, and preferably in the range of 55 to 70 ° C. when using aerobic thermophiles such as Bacillus bacteria. And especially the range of 60-65 degreeC is more preferable. Moreover, the pH at the time of solubilization process is also set to become the range of pH 6-9, Preferably it is the range of 7-8 similarly to Embodiment 1.

Embodiment 6

In the present embodiment, two sets of anoxic tanks are formed, and only one set of aeration tanks is formed, which is different from the embodiments 3 to 5 in this respect.

That is, as shown in FIG. 7, the treatment apparatus of the present embodiment includes a pre-oxygen tank 11, an anaerobic tank 4, a compatible tank 12, an oxygen-free tank 6, an aeration tank 13, a precipitation tank 8, The concentrator 9 and the solubilization tank 2 are provided.

In the present embodiment, the raw water introduced into the anaerobic tank 4 is supplied to the compatible tank 12.

The compatible tank 12 has a function of changing the return path of the sludge from the aeration tank 13 and the treatment liquid (nitration liquid) in accordance with the degree of denitrification of the inflow sewage. For example, the phosphorus release reaction of the return sludge in the anaerobic state is promoted by using as an anaerobic tank at a high denitrification period during the summer season, and as an anoxic tank at a low denitrification period during the winter season. The denitrification reaction of the nitride liquid returned to (11) or the compatible tank 12 is promoted.

In this way, after the treatment in the compatible tank 12 is performed, the raw water is supplied to the oxygen-free tank 6 for denitrification, and then supplied to the aeration tank 13 for aerobic biotreatment by aeration agitation. Subsequently, it is supplied from the aeration tank 13 to the precipitation tank 8, solid-liquid separation is performed in this precipitation tank 8, and the separated liquid component is discharged suitably. In addition, sludge as a solid component separated and precipitated is supplied to the concentrator 9 and supplied to the solubilization tank 2. In this case, the aeration tank 13 has a function of removing BOD and nitriding. A part of the nitride liquid, which is the treatment liquid of the aeration tank 13, is returned to the total anoxic tank 11, preferably an oxygen-free tank 6 (not shown).

In addition, the sludge solubilized in the solubilization tank 2 is returned to the compatibility tank 12, and the compatibility tank 12, the oxygen-free tank 6, the aeration tank 13, the precipitation tank 8, the concentrator 9, the solubilization tank (2) will be cycled. The sludge separated in the settling tank 8 is not only supplied to the concentrator 9 but also returned to the total oxygen free tank 11. The sludge is also returned from the anaerobic tank 4 and the compatible tank 12 to the total oxygen free tank 11.

It is preferable to set HRT of the solubilization tank 2 to 12 to 72 hours similarly to Embodiment 3, It is more preferable to set to 24 to 72 hours, It is most preferable to set to 36 to 48 hours.

HRT of tanks other than the solubilization tank (2) is 0.5 to 1.5 hours in the total anoxic tank (11), 0.5 to 2 hours in the anaerobic tank (4), 0.5 to 1 hour in the compatible tank (12) and 1 to 3 in the oxygen-free tank (6). It is preferable to set it as 3 to 6 hours in the aeration tank 13 for time, 0.5 to 1 hour in the total anoxic tank 11, 0.5 to 1 hour in the anaerobic tank 4, 0.5 to 1 hour in the compatibility tank 12, anoxic tank It is more preferable to set it as 3.5 to 5 hours in 1 to 2 hours and aeration tank 13 in (6).

As microorganisms for producing solubilizing enzymes for solubilizing sludge, it is preferable to use thermophilic bacteria, in particular, various Bacillus bacteria or Geobacilli bacteria.

The temperature at the time of solubilization is preferably in the range of 50 to 90 ° C. as in Embodiment 1, and in the case of using aerobic thermophiles such as Bacillus bacteria, the temperature is preferably set to a temperature in the range of 55 to 70 ° C. And especially the range of 60-65 degreeC is more preferable. Moreover, the pH at the time of solubilization process is also set to become the range of pH 6-9, Preferably it is the range of 7-8 similarly to Embodiment 1.

In addition, although the processing apparatus of this embodiment was equipped with the concentrator 9, it is not an essential condition for this invention to provide the condenser 9.

(Embodiment 7)

In this embodiment, as shown in FIG. 8, the nitride tank 10 is formed in the rear end side of the solubilization tank 2, and is different from the said Embodiment 6 in this point.

That is, in this embodiment, the sludge solubilized by the solubilization tank 2 is supplied to the nitriding tank 10, and the ammonia in the sludge is converted into nitrous acid or nitric acid in the nitriding tank 10, and then returned to the compatible tank 12. Will be. The sludge separated in the settling tank 8 is supplied to the concentrator 9 in the same manner as in the sixth embodiment, and is fed directly to the nitriding tank 10 in this embodiment in addition to being returned to the total oxygen free tank 11.

Other configurations and processing procedures are the same as those in the sixth embodiment, and description thereof is omitted.

In addition, it is preferable to set HRT of the solubilization tank 2 to 12 to 72 hours similarly to Embodiment 5, It is more preferable to set to 18 to 48 hours, It is most preferable to set to 20 to 36 hours .

As microorganisms for producing solubilizing enzymes for solubilizing sludge, it is preferable to use thermophilic bacteria, in particular, various Bacillus bacteria or Geobacilli bacteria.

The temperature at the time of solubilization is preferably in the range of 50 to 90 ° C. as in Embodiment 1, and preferably in the range of 55 to 70 ° C. when using aerobic thermophiles such as Bacillus bacteria. And especially the range of 60-65 degreeC is more preferable. Moreover, the pH at the time of solubilization process is also set to become the range of pH 6-9, Preferably it is the range of 7-8 similarly to Embodiment 1.

Embodiment 8

As shown in Fig. 9, the treatment apparatus of this embodiment includes a dissolved oxygen reduction tank 16, an anaerobic tank 4, an oxygen-free tank 6, an aeration tank 13, a precipitation tank 8, a concentrator 9, and a solubilization tank ( 2) is provided. In the present embodiment, in addition to supplying the anaerobic treatment water treated in the anaerobic tank 4 to the anoxic tank 6, the treated water treated in the dissolved oxygen reduction tank 16 to reduce the dissolved oxygen is also supplied to the anaerobic tank 6.

The treated water supplied to the oxygen-free tank 6 and denitrified again is supplied to the aeration tank 13, aerobicly treated by aeration agitation, and supplied to the precipitation tank 8 to be solid-liquid separated. The separated liquid fraction is appropriately discharged and the like, and the separated solid sludge is supplied to the concentrator 9, and a part of the sludge is returned to the aeration tank 13.

In addition, the treatment liquid of the aeration tank 13, ie, the nitriding liquid is denitrified by conveying a part of the nitriding liquid to the oxygen-free tank 6 via the dissolved oxygen reduction tank 16. The denitrification efficiency can be stabilized by introducing a nitriding liquid into an oxygen-free tank to reduce dissolved oxygen in the nitriding liquid.

In addition, the sludge concentrated in the concentrator 9 is supplied to the solubilization tank 2 and solubilized, and is returned to the dissolved oxygen reduction tank 16 thereafter.

In addition, the sludge supplied to the oxygen-free tank 6 is also conveyed to the anaerobic tank 4, and is returned to the dissolved oxygen reduction tank 16 from the anaerobic tank 4 again.

It is preferable to set HRT of the solubilization tank 2 to 12 to 72 hours similarly to Embodiment 3, It is more preferable to set to 24 to 72 hours, It is most preferable to set to 36 to 48 hours.

HRT in tanks other than the solubilization tank (2) is 0.15 to 0.3 hours in the dissolved oxygen reduction tank (16), 0.5 to 2 hours in the anaerobic tank (4), 1 to 3 hours in the oxygen-free tank (6), 3 to 3 in the aeration tank (13). It is preferable to set it as 6 hours, and it is 0.17 to 0.25 hours in the dissolved oxygen reduction tank 16, 1 to 1.5 hours in the anaerobic tank 4, 1 to 2 hours in the oxygen-free tank 6, and 3.5 to 5 hours in the aeration tank 13. It is more preferable to set it as.

As microorganisms for producing solubilizing enzymes for solubilizing sludge, it is preferable to use thermophilic bacteria, in particular, various Bacillus bacteria or Geobacilli bacteria.

The temperature at the time of solubilization is preferably in the range of 50 to 90 ° C. as in Embodiment 1, and preferably in the range of 55 to 70 ° C. when using aerobic thermophiles such as Bacillus bacteria. And especially the range of 60-65 degreeC is more preferable. Moreover, the pH at the time of solubilization process is also set to become the range of pH 6-9, Preferably it is the range of 7-8 similarly to Embodiment 1.

(Embodiment 9)

In this embodiment, as shown in FIG. 10, the nitride tank 10 is formed in the rear end side of the solubilization tank 2, and is different from the said Embodiment 8 in this point.

That is, in this embodiment, the sludge solubilized by the solubilization tank 2 is supplied to the nitriding tank 10, and the ammonia in the sludge is converted into nitrous acid or nitric acid in the nitriding tank 10, and then dissolved oxygen reduction tank 16 Will be returned. Moreover, a part of sludge of the precipitation tank 8 is supplied to the nitriding tank 10, and nitriding process is hold | maintained.

Since other configurations and processing procedures are the same as those in the eighth embodiment, the description thereof is omitted.

In addition, it is preferable to set HRT of the solubilization tank 2 to 12 to 72 hours similarly to Embodiment 5, It is more preferable to set to 18 to 48 hours, It is most preferable to set to 20 to 36 hours .

As microorganisms for producing solubilizing enzymes for solubilizing sludge, it is preferable to use thermophilic bacteria, in particular, various Bacillus bacteria and Geobacilli bacteria.

The temperature at the time of solubilization is preferably in the range of 50 to 90 ° C. as in Embodiment 1, and preferably in the range of 55 to 70 ° C. when using aerobic thermophiles such as Bacillus bacteria. And especially the range of 60-65 degreeC is more preferable. Moreover, the pH at the time of solubilization process is also set to become the range of pH 6-9, Preferably it is the range of 7-8 similarly to Embodiment 1.

Embodiment 10

As shown in FIG. 11, the apparatus for treating organic wastewater of the present embodiment includes an anaerobic tank 4, an anoxic tank 6, an aeration tank 13, a precipitation tank 8, and a solubilization tank 2.

In this embodiment, the anaerobic treatment of raw water is performed in the anaerobic tank 4, the phosphorus component in a sludge is discharged, it is supplied to the anoxic tank 6, and denitrification is performed in the anoxic tank 6. The treatment liquid denitrified in the oxygen-free tank 6 is supplied to the aeration tank 13, and the ammonia contained in the sludge in the aeration tank 13 is changed to nitrous acid or nitric acid. That is, nitriding is performed in the aeration tank 13.

Subsequently, the treatment liquid nitrified in the aeration tank 13 is supplied to the precipitation tank 8. In this settling tank (8), solid-liquid separation is carried out, the separated liquid fraction is discharged, etc., and a part of the sludge which is separated and precipitated is supplied to the solubilization tank (2), and the rest is returned to the anaerobic tank (4). Is returned.

The sludge after the solubilization treatment is returned to the oxygen-free tank 6, and the denitrification in the oxygen-free tank 6, the treatment in the aeration tank 13, the solid-liquid separation in the precipitation tank 8, and the solubilization treatment in the solubilization tank 2 are It will be repeated repeatedly. In addition, a part of the nitride liquid treated in the aeration tank 13 is returned to the anoxic tank 6 or the anaerobic tank 4 and denitrified in the anoxic tank 6.

It is preferable to set HRT of the solubilization tank 2 to 12 to 72 hours similarly to Embodiment 3, It is more preferable to set to 24 to 72 hours, It is most preferable to set to 36 to 48 hours.

HRT in tanks other than the solubilization tank (2) is 0.15 to 0.3 hours in the dissolved oxygen reduction tank (16), 0.5 to 2 hours in the anaerobic tank (4), 1 to 3 hours in the oxygen-free tank (6), 3 to 3 in the aerobic tank (17). It is preferable to set it as 6 hours, 0.17 to 0.25 hours in the dissolved oxygen reduction tank 16, 1 to 1.5 hours in the anaerobic tank 4, 1-2 hours in the anoxic tank 6, and 3.5 to 5 hours in the aerobic tank 17. It is more preferable to set it as.

As microorganisms for producing solubilizing enzymes for solubilizing sludge, it is preferable to use thermophilic bacteria, in particular, various Bacillus bacteria or Geobacilli bacteria.

The temperature at the time of solubilization is preferably in the range of 50 to 90 ° C. as in Embodiment 1, and preferably in the range of 55 to 70 ° C. when using aerobic thermophiles such as Bacillus bacteria. And especially the range of 60-65 degreeC is more preferable. Moreover, the pH at the time of solubilization process is also set to become the range of pH 6-9, Preferably it is the range of 7-8 similarly to Embodiment 1.

(Embodiment 11)

In this embodiment, as shown in FIG. 12, the sludge solubilized by the solubilization tank 2 is conveyed to the anaerobic tank 4, and it differs from the case of Embodiment 10 in which it was conveyed to the oxygen-free tank 6 in this respect.

Anaerobic treatment in the anaerobic tank (4), denitrification in the oxygen-free tank (6), nitriding treatment in the aeration tank (13), solid-liquid separation in the precipitation tank (8), solubilization treatment in the solubilization tank (2) are embodiments. Same as 10, the description is omitted. Also in this embodiment, a part of nitride liquid is conveyed to the anaerobic tank 6 or the anaerobic tank 4. As shown in FIG.

It is preferable to set HRT of the solubilization tank 2 to 12 to 72 hours similarly to Embodiment 3, It is more preferable to set to 24 to 72 hours, It is most preferable to set to 36 to 48 hours.

As microorganisms for producing solubilizing enzymes for solubilizing sludge, it is preferable to use thermophilic bacteria, in particular, various Bacillus bacteria or Geobacilli bacteria.

The temperature at the time of solubilization is preferably in the range of 50 to 90 ° C. as in Embodiment 1, and preferably in the range of 55 to 70 ° C. when using aerobic thermophiles such as Bacillus bacteria. And especially the range of 60-65 degreeC is more preferable. Moreover, the pH at the time of solubilization process is also set to become the range of pH 6-9, Preferably it is the range of 7-8 similarly to Embodiment 1.

(Twelfth Embodiment)

In this embodiment, as shown in FIG. 13, the nitride tank 10 is formed in the rear end of the solubilization tank 2. As shown in FIG. In this embodiment, the sludge treated in the solubilization tank 2 is supplied to the nitriding tank 10, and the ammonia in the sludge is converted into nitrous acid or nitric acid in the nitriding tank 10, and then returned to the anoxic tank 6. In addition, sludge is supplied to the nitriding tank 10 from the precipitation tank 8.

Anaerobic treatment in the anaerobic tank (4), denitrification in the oxygen-free tank (6), nitriding treatment in the aeration tank (13), solid-liquid separation in the precipitation tank (8), solubilization treatment in the solubilization tank (2) are embodiments. Same as 11, the description is omitted.

However, the HRT of the solubilization tank 2 is preferably set to 12 to 72 hours, more preferably 18 to 48 hours, and most preferably 20 to 36 hours, as in the fifth embodiment. .

As microorganisms for producing solubilizing enzymes for solubilizing sludge, it is preferable to use thermophilic bacteria, in particular, various Bacillus bacteria or Geobacilli bacteria.

The temperature at the time of solubilization is preferably in the range of 50 to 90 ° C. as in Embodiment 1, and preferably in the range of 55 to 70 ° C. when using aerobic thermophiles such as Bacillus bacteria. And especially the range of 60-65 degreeC is more preferable. Moreover, the pH at the time of solubilization process is also set to become the range of pH 6-9, Preferably it is the range of 7-8 similarly to Embodiment 1.

(Embodiment 13)

Also in this embodiment, the nitriding tank 10 is formed in the rear end of the solubilization tank 2 similarly to Embodiment 12, but the sludge after the process in the nitriding tank 10 is shown in FIG. Is different from the case of the twelfth embodiment in which it is conveyed to the oxygen-free tank 6 in this respect.

Anaerobic treatment in the anaerobic tank (4), denitrification in the oxygen-free tank (6), nitriding treatment in the aeration tank (13), solid-liquid separation in the precipitation tank (8), solubilization treatment in the solubilization tank (2) are embodiments. Same as 10, the description is omitted.

It is preferable to set HRT of the solubilization tank 2 to 12 to 72 hours similarly to Embodiment 5, to set it to 18 to 48 hours, and it is most preferable to set it to 20 to 36 hours.

Also in this embodiment, supply of sludge from the settling tank 8 is needed for the nitriding tank 10 similarly to Embodiment 12. FIG.

As microorganisms for producing solubilizing enzymes for solubilizing sludge, it is preferable to use thermophilic bacteria, in particular, various Bacillus bacteria or Geobacilli bacteria.

The temperature at the time of solubilization is preferably in the range of 50 to 90 ° C. as in Embodiment 1, and preferably in the range of 55 to 70 ° C. when using aerobic thermophiles such as Bacillus bacteria. And especially the range of 60-65 degreeC is more preferable. Moreover, the pH at the time of solubilization process is also set to become the range of pH 6-9, Preferably it is the range of 7-8 similarly to Embodiment 1.

(Embodiment 14)

As shown in FIG. 15, the organic wastewater processing apparatus of this embodiment is comprised by the reaction tank 1, the solubilization tank 2, and the storage tank 3. As shown in FIG. In the reactor 1, organic wastewater is treated in a batch manner as in the first embodiment.

In this embodiment, as shown in FIG. 16, the process of the anaerobic process by stirring and the aerobic process by aeration is repeated three times, and the process of sedimentation, solid-liquid separation, and solubilization process by aeration stop is circulated after that. . Repetitive processes of anaerobic treatment and aerobic treatment, precipitation and solid-liquid separation are carried out in the reaction tank (1), and solubilization is carried out in the solubilization tank (2).

Batch treatment of a series of wastewater treatments of treatment water discharge from inflow of raw water can be adjusted for each process so as to be carried out a plurality of times (for example, 2 to 4 times) per day, but depending on the nature and quantity of wastewater, etc. The treatment time of each process may be adjusted to carry out batch treatment once a day or twice a three days.

The wastewater treatment time is, for example, inflow 60 minutes, anaerobic 60 minutes, aerobic 70 minutes, anaerobic 30 minutes, aerobic 80 minutes, anaerobic 20 minutes, aerobic 10 minutes, precipitate 40 minutes, discharge 40 minutes.

In this embodiment, nitriding is performed in an aerobic treatment process, and denitrification is performed in an anaerobic treatment process.

The solubilization liquid after the solubilization treatment is returned to the reaction tank 2 in the first (first) aerobic treatment step. The conveyance timing is determined in relation to the processing time of the first exhalation treatment step, but is set 3 hours to 30 minutes before the aeration stop, preferably 1 hour to 30 minutes before.

In this embodiment, since the storage tank 3 is formed in the rear end of the solubilization tank 2, the solubilization liquid processed by the solubilization tank 2 is once stored in the storage tank 3, and the reaction tank 2 in the 1st aerobic treatment process is carried out. The timing, quantity, etc. which convey a solubilization liquid can be adjusted easily, and it is preferable.

12-72 hours are preferable, as for HRT of the solubilization tank 2, 18-48 hours are more preferable, and 20-36 hours are the most preferable.

As a microorganism which produces | generates the solubilization enzyme for solubilizing sludge, it is preferable to use thermophilic bacteria, especially the various Bacillus genus and the genus Bacillus genus bacteria disclosed in Embodiment 1.

The temperature at the time of solubilization is preferably in the range of 50 to 90 ° C. as in Embodiment 1, and preferably in the range of 55 to 70 ° C. when using aerobic thermophiles such as Bacillus bacteria. And especially the range of 60-65 degreeC is more preferable. In addition, the pH at the time of solubilization is also set to be in the range of pH 6-9, preferably 7-8, similarly to Embodiment 1.

(Embodiment 15)

In the organic wastewater treatment apparatus of this embodiment, as shown in FIG. 17, a storage tank 3 is formed at the rear end of the reaction tank 1, and a solubilization tank 2 is formed at the rear end thereof. In this embodiment, the sludge after nitriding and denitrification is once stored in the storage tank 3, and the sludge of the required amount which should be solubilized is supplied to the solubilization tank 2.

Thus, by supplying only the sludge of the required amount to be solubilized to the solubilization tank 2, the amount of solubilization liquid returned to the aerobic treatment process can also be adjusted in advance.

The process of anaerobic treatment and aerobic treatment is repeated, and sedimentation and solid-liquid separation are the same as that of Embodiment 14.

12-72 hours are preferable, as for HRT of the solubilization tank 2, 18-48 hours are more preferable, and 20-36 hours are the most preferable.

As a microorganism which produces | generates the solubilization enzyme for solubilizing sludge, it is preferable to use thermophilic bacteria, especially the various Bacillus genus and the genus Bacillus genus bacteria disclosed in Embodiment 1.

The temperature at the time of solubilization is preferably in the range of 50 to 90 ° C. as in Embodiment 1, and preferably in the range of 55 to 70 ° C. when using aerobic thermophiles such as Bacillus bacteria. And especially the range of 60-65 degreeC is more preferable. In addition, the pH at the time of solubilization is also set to be in the range of pH 6-9, preferably 7-8, similarly to Embodiment 1.

Embodiment 16

This embodiment is an embodiment provided with the means which removes the phosphorus, when the sludge which generate | occur | produces by biological treatment, such as said nitriding and denitrification, is contained.

In this embodiment, a coagulant such as polyaluminum chloride is added at the rear end side of the precipitation tank 8 as in each of the above embodiments, and phosphorus is removed by coagulation precipitation, or a filter medium is formed to remove phosphorus by coagulation filtration.

In each of the above embodiments, in the embodiment provided with the anaerobic treatment step and the aerobic treatment step (aeration treatment step), if phosphorus is contained in the treated water or sludge, the phosphorus is released from the microorganisms in the sludge in the anaerobic treatment step, and the aerobic treatment is performed. It enters microorganisms in the process. However, even if phosphorus is released or introduced, the solubilization treatment of sludge may introduce the treatment solution containing phosphorus out of the system, and both the anaerobic treatment process and the aerobic treatment process may cause phosphorus release and inflow. The effectiveness of the function cannot be achieved.

Thus, by forming the above-described phosphorus removing means, it is possible to actively remove phosphorus contained in the treated water or sludge. This can be applied to both continuous processing and batch processing.

(Embodiment 17)

In the present embodiment, as a phosphorus removing means, a phosphorus discharge tank having phosphorus separation means is formed on the rear end side of the precipitation tank 8 by changing to means using the flocculant or the like, and the sludge separated from the precipitation tank 8 is In the phosphorus discharge tank, for example, phosphorus is released by exposing phosphorus from a sludge such as anaerobic or heated state, and the released phosphorus is separated into phosphorus discharge sludge and phosphorus eluate, and a flocculant is added to the phosphorus discharge liquid. It is configured to be removed. Then, the phosphorus discharge sludge is solubilized.

Therefore, also in this embodiment, the various tanks similar to each said embodiment can be provided in the front end side of the precipitation tank 8. This can be applied to both continuous processing and batch processing.

(Embodiment 18)

In this embodiment, an iron plate, iron particles, steel wool, or the like is introduced into the reaction tank 1, the aeration tank 13, the nitride tank 10, the solubilization tank 2, the anoxic tank 6, etc. of the respective embodiments, and the phosphorus component is added. Embodiment which removes phosphorus by attaching to iron.

In this embodiment, the reaction tank (1) and the aeration tank (13) already installed in the processing apparatus without using a flocculant like the sixteenth embodiment and forming a phosphorus discharge tank for phosphorus release as in the seventeenth embodiment separately By simply adding an iron material to the solubilization tank (2), the oxygen-free tank (6), etc., the phosphorus component can be attached to the iron material to easily remove phosphorus.

(Other Embodiments)

In addition, in the above Embodiments 3, 4, 5 and the like, the acid fermentation liquid obtained by gas-decomposing and fermenting the residue discharged from the food factory is used as the liquid to be treated. May be used.

In addition, forming the fermentation broth 3 as in this embodiment 3, 4, 5 is not an essential condition in the present invention. For example, as shown in Fig. 18, there is no fermentation broth 3, and anaerobic tanks 4 and 1 The treatment apparatus provided with the secondary aeration tank 5, the anoxic tank 6, the secondary aeration tank 7, the precipitation tank 8, and the solubilization tank 2 can also be used. For example, when only the sewage from a sewage treatment plant is treated, this treatment apparatus shown in FIG. 18 can be suitably used.

In addition, although flue gas may be discharged from the solubilization tank 2, by introducing such flue gas into the nitriding tank or aeration tank of the above embodiment, the odor of the flue gas can be removed, and the hot flue gas is introduced into the nitriding tank or aeration tank. Since the temperature of each tank can be made higher than the aeration by normal air, the activity of microorganisms can be increased, and as a result, the treatment efficiency can be increased, which is preferable.

In addition, any kind of organic wastewater to be treated may be used.

Claims (21)

A method of biologically treating organic wastewater, wherein the organic wastewater is nitrified and denitrified, and then the sludge generated by nitrification and denitrification is solubilized by thermophilic bacteria to a temperature of 50 to 90 ° C. Way. The process according to claim 1, wherein nitriding and denitrification of the organic wastewater is carried out batchwise in the reaction tank (1), and the nitriding is carried out by aeration, and denitrification is carried out by stopping the aeration, further stopping the aeration. The processing method of the organic wastewater in which a solubilization liquid is returned to the reaction tank 1 three hours-30 minutes ago. delete delete The method for treating organic wastewater according to claim 2, wherein the solubilization treatment liquid is returned to the reactor 1 hour to 30 minutes before the aeration is stopped. The method for treating organic wastewater according to claim 1, wherein nitrification and denitrification of the organic wastewater is carried out by an anaerobic treatment process, a primary aeration process, a denitrification process in an anoxic tank, and a secondary aeration process. The method for treating organic wastewater according to claim 1, wherein the nitrification and denitrification of the organic wastewater is carried out by a denitrification step in an anaerobic tank, an anaerobic treatment step, a treatment step in a compatible tank, a denitrification step in an oxygen free tank, and an aeration step. The method for treating organic wastewater according to claim 6 or 7, wherein nitriding is performed after solubilization. The organic wastewater treatment method according to claim 1, wherein the nitrification and denitrification treatment of the organic wastewater is carried out by an anaerobic treatment step, a denitrification step in an anoxic tank, and an aeration step, and the dissolved oxygen of the treatment solution after solubilization is reduced. The method for treating organic wastewater according to claim 1, wherein nitrification and denitrification of the organic wastewater is carried out by an anaerobic treatment step, a denitrification step in an anoxic tank, and an aeration step. The method for treating organic wastewater according to claim 1 or 2, wherein sludge is concentrated before solubilization. The method for treating organic wastewater according to claim 1 or 2, wherein the thermophilic bacteria solubilizing sludge are aerobic thermophilic bacteria. The method for treating organic wastewater according to claim 12, wherein the aerobic thermophile is a microorganism of the genus Bacillus. The method for treating organic wastewater according to claim 1 or 2, further comprising the step of removing phosphorus in the treated water discharged out of the system. An apparatus for biologically treating organic wastewater, comprising: a means for nitriding and denitrifying organic wastewater, and a solubilization tank for solubilizing sludge generated by nitrification and denitrification by thermophilic bacteria at a temperature of 50 to 90 ° C. Organic wastewater treatment device. The process according to claim 15, wherein the means for nitriding and denitrifying the organic wastewater is subjected to nitriding and denitrification in the batch reactor 1, performing the nitriding treatment by aeration, performing denitrification by stopping the aeration, and further, aeration. 3 hours-30 minutes before stopping a process, the organic wastewater treating apparatus which is a means of conveying a solubilization process liquid to the reaction tank (1). The organic wastewater according to claim 15, wherein the means for nitriding and denitrifying the organic wastewater is a means for nitriding and denitrifying the anaerobic tank (4), the primary aeration tank (5), the anoxic tank (6), and the secondary aeration tank (7). Processing unit. The means for nitriding and denitrifying organic wastewater is a means for nitriding and denitrifying by the total anoxic tank 11, the anaerobic tank 4, the compatible tank 12, the anoxic tank 6, and the aeration tank 13. Organic wastewater treatment device. The method according to claim 15, wherein the means for nitriding and denitrifying the organic wastewater is a means for nitriding and denitrifying by the anaerobic tank 4, the anoxic tank 6, and the aeration tank 13, and reducing dissolved oxygen in the treatment solution after solubilization treatment. An apparatus for treating organic wastewater, in which a dissolved oxygen reduction tank 16 is formed. The apparatus for treating organic wastewater according to claim 15, wherein the means for nitriding and denitrifying the organic wastewater is a means for nitriding and denitrifying by the anaerobic tank (4), the anoxic tank (6), and the aeration tank (13). The treatment apparatus for organic wastewater according to any one of claims 15 to 20, further comprising means for removing phosphorus in the treated water discharged out of the system.

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