JP6684127B2 - Fermentation deodorization system and fermentation deodorization method - Google Patents

Description

The present invention, deodorizer for deodorizing a fermentation installation comprising a heating blower mechanism for supplying warm air into the fermenter and the fermentation tank to fermentation treatment of organic sludge, odor gas discharged from the fermenter And a fermentation deodorizing system and method.

  At the human waste treatment plant that purifies human waste or organic waste such as septic tank sludge, biological treatment equipment that purifies by the action of microorganisms is constructed, and excess sludge generated at the biological treatment equipment is input to the fermentation equipment. After being fermented, it is effectively used as compost.

  The organic sludge to be fermented contains excess sludge generated in biological treatment tanks that biologically treat the liquid content of human waste or septic tank sludge, and solids of human waste and septic tank sludge. A large amount of gas and water vapor is generated.

  In Patent Document 1, in a fermenter for fermenting organic waste such as dehydrated sludge and kitchen waste while aerating, at least an atmosphere having a saturated humidity or less is aerated, and the water and the like generated in the fermenter are dispersed together. Disclosed is an odor treatment method for a composting device that discharges an odor composed of mood and aeration.

  The odor treatment method, the odor discharged from the composting device generates heat by fermenting in the fermenter under aerobic conditions by aeration, and a heat-generating odor containing moisture and dust evaporated by the heat generation. That is, after removing dust and deodorizing the exothermic odor with a liquid contact tower installed to make gas-liquid contact with activated sludge, the water containing odor is further condensed with the water by a condensing tower. A return line is provided for returning to a ventilation side of the fermenter by discharging it to the outside under saturated humidity.

Patent No. 3510539

  However, in the odor treatment method disclosed in Patent Document 1, the odorous gas of 40 to 50 ° C. that has passed through the liquid contact tower is condensed in the condensing tower and cooled to 15 to 25 ° C., and then the odorous gas of the fermentation tank is fed through the return line. Since it was configured to return it to the ventilation side, the heat retained by the odorous gas was wasted, and there was room for improvement in terms of energy efficiency.

  In view of the above-mentioned problems, an object of the present invention is to provide a fermentation deodorization system and a fermentation deodorization method having a high deodorizing effect and energy efficiency.

  In order to achieve the above-mentioned object, the first characteristic configuration of the fermentation deodorization system according to the present invention is, as described in claim 1 of the document of the claims, a fermentation tank for fermenting organic sludge, and the fermentation. A heating air blowing mechanism that supplies heated air to the tank, and a deodorizing device that performs a deodorizing process by gas-liquid contacting a gas to be treated containing an odorous gas and steam discharged from the fermentation tank and a deodorizing liquid In the fermentation deodorization system, there is provided a circulation supply passage that circulates and supplies at least a part of the gas to be treated exhausted from the deodorization device to the warm air blowing mechanism without cooling.

  By supplying the air heated by the heating / blowing mechanism to the fermenter, the fermenter can be controlled at a favorable temperature and the fermentation efficiency can be improved. The odorous gas generated in the fermenter is transported to the outside of the tank by the heated air together with the steam, and the odorous components are removed by the deodorizing device. After being exhausted from the deodorizing device, a part thereof is circulated and supplied to the warming and blowing mechanism without being cooled, and after being heated by the warming and blowing mechanism, is supplied to the fermenter.

  That is, it is possible to greatly reduce the total amount of odors that are discharged to the outside of the fermenter system by circulating supply of warm air and processed in the deodorization tower, and the temperature of the circulation-supplied air does not drop significantly. Since it is supplied to the fermenter through the heating / blowing mechanism at about 50 ° C, the steam generated in the fermentation tank can be sufficiently taken out of the tank, and the energy cost required for the heating / blowing mechanism or the like is reduced. Compared with the case of heating air at room temperature, the cost can be significantly reduced, and the chemical cost for deodorization can be reduced.

  Since it is not necessary to provide a condenser as in the conventional case, the facility cost can be reduced. Further, since the dust contained in the gas to be deodorized is efficiently captured by the deodorization treatment liquid in the gas-liquid mixing section, there is no fear that the dust will adhere to the air circulation supply path and cause clogging. The deodorizing treatment liquid that has captured these odorous gas and dust is discharged from the drainage unit, a new deodorizing treatment liquid is supplied from the liquid supply unit, and the same process is repeated.

The second characteristic configuration is, in addition to the first characteristic configuration described above, in addition to the first characteristic configuration, as described in claim 2, the deodorizing device discharges a gas to be treated containing odorous gas and water vapor discharged from the fermentation tank. An air supply unit for guiding, a liquid supply unit for supplying a deodorizing treatment liquid, and a gas liquid for deodorizing treatment by injecting the deodorizing target gas guided from the air supplying unit into the deodorizing treatment liquid supplied from the liquid supplying unit. A mixing unit, a drainage unit for discharging the deodorizing treatment liquid used for the deodorizing treatment in the gas-liquid mixing unit, and an exhaust unit for discharging the gas to be treated deodorized in the gas-liquid mixing unit, are configured. There is a point.

Because the treated gas containing odorous gases and water vapor is discharged from the fermentor gas-liquid mixed efficiently by being pressed into the deodorized liquid from the air supply unit, odor fillers deodorizing treatment liquid has been sprayed Superior dust removal effect and water removal compared to filler type liquid contact towers that pass gas and spray type liquid contact towers that pass odorous gas into the space where the deodorizing liquid is sprayed The effect is demonstrated.

As described in claim 3, the third characteristic constitution is, in addition to the second characteristic constitution described above, provided with a nitrification and denitrification treatment tank for biologically treating liquid content of human waste or septic tank sludge. A liquid supply path for supplying the activated sludge circulated and supplied in the nitrogen treatment tank as a deodorizing treatment liquid to the liquid supply unit, and the deodorized activated sludge discharged from the liquid discharge unit is returned to the nitrification denitrification treatment tank. It is configured with a return path.

  According to the above configuration, the following action and effect can be obtained in addition to the action and effect by the first or second characteristic configuration. Since the returned sludge with a low ammonia concentration after nitrification and denitrification in a nitrifying and denitrifying tank using microorganisms and the nitrifying circulating liquid are supplied to the liquid supply section as a deodorizing treatment liquid, ammonia contained in the deodorizing target gas The components become sufficiently dissolved in the deodorizing treatment liquid. After that, the deodorizing treatment liquid is circulated and supplied to the nitrification and denitrification treatment equipment and is subjected to nitrification and denitrification treatment. Therefore, even if ammonia is dissolved in the deodorization treatment liquid, proper nitrification and denitrification treatment is inherently performed. Moreover, since the returned sludge and the nitrification circulating liquid, which are the deodorization treatment liquid that has been heat-exchanged and heated by the deodorization device, are returned to the nitrification denitrification treatment tank, the nitrification denitrification treatment tank is adjusted to a good temperature, especially in winter. In addition, the nitrification and denitrification efficiency will be greatly improved.

  The fourth characteristic configuration is, in addition to the third characteristic configuration described above, in addition to the third characteristic configuration, the deodorizing device includes a coagulant supply mechanism for adding an iron-based inorganic coagulant to a deodorizing treatment liquid. It is in the point of being prepared.

  When the sulfur-based odorous gas contained in the deodorizing target gas is mixed with the deodorizing treatment liquid supplied from the liquid supply part in the gas-liquid mixing part, it reacts with the iron-based inorganic coagulant added by the coagulant supply mechanism. Then, as insoluble iron sulfide or sulfur is deposited on the liquid side from the gas, it is trapped in the deodorizing treatment liquid.

  Incidentally, as an iron-based inorganic coagulant added to the deodorizing treatment liquid by the coagulant supply mechanism, a flocculation containing the excess iron-based inorganic coagulant added to the solid-liquid separation liquid of the excess sludge after nitrification denitrification treatment Sludge can also be used, and in that case, it is not necessary to prepare an iron-based inorganic coagulant dedicated to the deodorization treatment device, and the running cost can be further reduced.

The first characteristic configuration of the fermentation deodorizing method according to the present invention is, as described in claim 5, a fermentation step of performing a fermentation treatment of organic sludge in a fermenter and a warm air blowing for supplying warm air to the fermentation step. A fermentation deodorizing method comprising a step and a deodorizing step of performing a deodorizing treatment by gas-liquid contacting a gas to be treated containing a odorous gas and steam generated in the fermentation step and a deodorizing treatment liquid, wherein the deodorizing step is performed. A point is that a circulation supply step is provided to circulate and supply at least a part of the exhausted gas to be processed to the warm air blowing step without cooling.

  The second characteristic configuration is, as described in claim 6, in addition to the first characteristic configuration described above, in the deodorizing step, a gas to be treated containing odorous gas and steam generated in the fermentation step is supplied. A gas supply step of guiding the air to the air part, a liquid supply step of supplying a deodorizing treatment liquid, a gas to be deodorized guided in the air supplying step, and a deodorizing treatment liquid supplied in the liquid supplying step by gas-liquid mixing. Gas-liquid mixing step of performing deodorizing treatment by means of degassing, a draining step of discharging the deodorizing treatment liquid used for deodorizing processing in the gas-liquid mixing step, and an exhausting step of exhausting the gas to be treated deodorized in the gas-liquid mixing step It is configured with and.

As described in claim 7, the third characteristic configuration includes, in addition to the second characteristic configuration described above , a nitrification denitrification treatment step of biologically treating the liquid content of human waste or septic tank sludge, The step is a step of supplying the returned sludge circulated and supplied in the nitrification and denitrification processing step as a deodorization processing solution through a supply path, and the draining step was used for the deodorization processing in the gas-liquid mixing step. This is a step of returning the deodorization treatment liquid to the nitrification and denitrification treatment step through a return passage.

  The fourth characteristic structure is, in addition to the third characteristic structure described above, in the deodorizing step, as described in the same claim 7, a coagulant supply step of adding an iron-based inorganic coagulant to a deodorizing treatment liquid. It is in the point of being prepared.

  As described above, according to the present invention, it is possible to provide a fermentation deodorization system and a fermentation deodorization method having a high deodorizing effect and high energy efficiency.

Illustration of fermentation equipment according to the present invention Illustration of deodorizing device Explanatory drawing of the fermentation deodorization system by this invention Explanatory drawing of night soil treatment equipment with built-in fermentation deodorization system Explanatory drawing of the deodorizing apparatus which showed another embodiment.

Hereinafter, a fermentation deodorization system and a fermentation deodorization method according to the present invention will be described.
As shown in FIG. 3, the fermentation deodorization system 100 includes a sludge transfer mechanism 31, a plurality of fermentation tanks 10, a heating air blower mechanism 20 for supplying heated air to each fermentation tank 10, and a compost transfer mechanism 32. The fermentation equipment 30 provided and the deodorizing device 50 for deodorizing the odorous gas discharged from the fermentation equipment 30 are provided.

  The organic sludge as a raw material is conveyed and supplied to each fermentation tank 10 by the sludge conveying mechanism 31, and the compost fermented in each fermentation tank 10 is accumulated by the compost conveying mechanism 32, packed, and then shipped. As the organic sludge, surplus sludge generated in the nitrification and denitrification treatment step for biologically treating the liquid content of night soil or septic tank sludge, or the solid content of night soil / sewage tank sludge is preferably used.

  Each fermenter 10 has an upper heating blower mechanism including a blower fan 21 and a heater 22 for supplying warm air from above the fermentor 10, and a blower fan 23 for supplying warm air from below the fermenter 10. A heating air blowing mechanism 20 of two systems including a lower heating air blowing mechanism provided with a heater 24 is provided.

  The warmed air supplied to each fermenter 10 by the warming and blowing mechanism 20 is attracted from the exhaust port provided at the top of each fermenter 10 along with odorous gas, water vapor, and dust generated in each fermenter 10. It is sucked out of the tank by the fan 25 and sent to the deodorizing device 50.

  The warmed air that has been introduced into the deodorizing device 50 is deodorized inside the deodorizing device 50 and, after dust and the like have been removed, is exhausted from the deodorizing device 50, and part of the warmed air that has been exhausted passes through the circulation supply path 28. It is circulated and supplied to the upper heating air blowing mechanism via the above, and the rest is further deodorized in the medium concentration deodorization tower.

  FIG. 1 shows details of the fermenter 10. The fermentor 10 is configured in a semi-cylindrical shape with a flat ceiling surface and an arcuate bottom section, and is provided with a motor-driven rotating shaft 12 radially provided with a plurality of stirring blades 13 along a horizontal axis. ing.

  A sludge input port 14 and an air supply port 15 are provided on the base end side ceiling portion, and an exhaust port 18 is provided on the other end side ceiling portion. A plurality of air supply ports 16 for supplying heated air for promoting fermentation are provided along the axial direction of the rotary shaft 12 at the bottom of the base end side, and the compost after the fermentation process is discharged to the bottom of the other end side. A compost discharge port 17 is provided.

  Air that is sucked by the blower fan 23 provided in the lower heating blower mechanism and heated by the heater 24 to 60 ° C. to 80 ° C. is supplied to the fermenter 10 during the fermentation process, and the rotary shaft 12 is rotationally driven, When the fermentation process is completed, the supply of warm air from the lower warm air blowing mechanism is stopped.

  The organic sludge charged into the fermentation tank 10 from the sludge charging port 14 is heated by the warm air supplied from the air supply port 16 while being stirred by the stirring blade 13 inside the fermentation tank 10. Inside the fermenter 10, the water contained in the sludge evaporates and the supplied oxygen promotes the aerobic fermentation process, and the stable fermentation process is maintained at the high fermentation temperature.

  The air supplied from the blower fan 21 provided in the upper heating / blowing mechanism is heated by the heater 22 from 70 ° C. to 80 ° C., and then supplied from the air supply port 15 into the fermentation tank 10.

  The warm air supplied from the upper warming and blowing mechanism mainly conveys ammonia and a sulfur-based odorous gas generated in the fermenter 10 toward the deodorizing device 50, and removes water as water vapor from the organic sludge. The warm air, which has been used for this purpose and has been lowered from about 50 ° C. to 60 ° C. accompanied by odorous gas, water vapor, and dust inside the fermenter 10, is introduced into the deodorizing device 50.

  A part of the gas to be treated, which has been gas-liquid contacted and deodorized by the deodorizing device 50 and has been cooled to 40 ° C. to 50 ° C., is circulated and supplied to the upper heating air blowing mechanism via the circulation supply passage 28, and the rest has a medium concentration. It is opened to the atmosphere through the deodorization tower 80 and the activated carbon adsorption tower 90.

  The heated air of 40 ° C to 50 ° C circulated and supplied through the circulation supply path 28 is mixed with the outside air by the upper heating air blowing mechanism, and then heated by the heater 22 to 70 ° C to 80 ° C, and is again fermented. Supplied to 10.

  Even when the air in the wet state exhausted from the fermenter 10 and reduced in temperature by the deodorizing device 50 is circulated through the circulation supply path 28 and heated by the heater 22, the saturated steam pressure rises, so that the fermentation is performed. The water vapor generated in the tank 10 can be efficiently taken out of the tank.

  In other words, by circulatingly supplying a part of the warm air discharged from the deodorizing device 50 to the fermentation tank 10, the total amount of warm air supplied to the fermentation tank can be reduced, and the warm air is circulated and supplied. Since the heated air is heated by the warm air blowing mechanism and the saturated steam pressure becomes high and is supplied to the fermenter, the energy cost required for the warm air blowing mechanism is greatly reduced compared to the case of heating air at room temperature. By reducing the total amount of warm air, chemical costs such as sodium hypochlorite for deodorization can be reduced, and running costs such as chemical costs and energy costs can be reduced to about 1/2. Become.

FIG. 2 shows the deodorizing device 50. In a so-called scrubber type deodorization treatment apparatus 50, an air supply section 52 that guides a gas to be treated containing odorous gas and water vapor discharged from the fermentation tank 10 , a liquid supply section 54 that supplies a deodorization treatment solution, and an air supply section. In the gas-liquid mixing sections 58b and 58d and the gas-liquid mixing sections 58b and 58d, in which the gas to be deodorized guided from 52 is pressed into the deodorization treatment liquid supplied from the liquid supply unit 54 to perform gas-liquid mixing and deodorization treatment. A drainage unit 55 that discharges the deodorization treatment liquid used for the deodorization treatment and an exhaust unit 53 that exhausts the gas to be treated deodorized by the gas-liquid mixing units 58b and 58d are provided. In the figure, reference numeral 56 is a drain valve for discharging the deodorizing treatment liquid from the inside of the apparatus at the time of maintenance or the like.

  The deodorizing device 50 is covered with an upper wall 51a, a left side wall 51b, a right side wall 51c, a bottom wall 51d, a front wall (not shown) and a back wall (not shown), and the internal space is a partition wall 59a, 59b, 59c. , 59d.

  Communication paths 57a, 57b, 57c, 57d are formed between the lower ends of the partition walls 59a, 59b, 59c, 59d and the bottom wall 51d, respectively, and a communication path 57e is formed between the partition wall 59b and the upper wall 51a. ing.

  The deodorizing treatment liquid supplied from the liquid supply unit 54 flows through the communication passages 57a, 57b, 57c, 57d, overflows the weir 59e, and flows out from the liquid discharge unit 55. The gas to be treated, which is the heated air that has flowed in from the air supply unit 52, flows downward in the inflow space 58a immediately below it and reaches the gas-liquid interface with the deodorizing treatment liquid, and pushes down the gas-liquid interface to delimit the partition wall. It flows over 59a and flows into the gas-liquid mixing section 58b.

  At this time, in the gas-liquid mixing section 58b, the contact between the deodorization treatment liquid and the treatment gas, which have been wound into small water droplets by the treatment gas, is promoted, and the gas-liquid mixture is efficiently mixed, so that the odor in the treatment gas is increased. At the same time that the components, water vapor, and fine particles are captured by the deodorization treatment liquid, the temperature of the gas to be treated decreases by about 10 ° C. due to contact with the deodorization treatment liquid.

  Furthermore, the gas to be treated that has risen to the space above the gas-liquid mixing portion 58b passes through the communication passage 57e, flows downward again in the inflow space 58c immediately below it, and reaches the gas-liquid interface with the deodorizing treatment liquid, The gas-liquid boundary surface is pushed down and flows over the partition wall 59c into the gas-liquid mixing section 58d, and in the same manner as the gas-liquid mixing section 58b, the gas-liquid mixing section 58d also deodorizes odorous components, water vapor and fine particles in the gas to be treated. Captured by the processing liquid.

  The gas to be treated, which has risen to the space above the gas-liquid mixing section 58d, passes through the communication passage 58e and flows into the gas-liquid separation section 60, comes into contact with the mist separator 59f composed of a mesh or corrugated plate, and deodorizes. After the mist such as the processing liquid and the water is separated, it is exhausted from the exhaust unit 53.

  The lower end of the partition wall 59a is set to be lower than the lower end of the partition wall 59c, and the lower end of the partition wall 59b is set to be lower than the lower end of the partition wall 59a. Further, the lower end of the partition wall 59c is set lower than the height of the weir 59e, and the lower end of the partition wall 59d is set lower than the lower end of the partition wall 59c.

  The air supply part 52 and the liquid supply part 54 are arranged so as to face each other with the inflow space 58a sandwiched therebetween, so that the pressure of the gas to be treated acting on the gas-liquid interface and the pressure of the deodorizing solution are balanced and the gas-liquid interface does not pulsate. Has been adjusted to. Therefore, the gas to be treated does not pass through the lower end of the partition wall 59a and the gas-liquid mixing opportunity is not lost.

  The deodorizing treatment liquid after gas-liquid contact in the gas-liquid mixing unit 58d flows through the communication passage 57d and overflows the weir 59e, and then is discharged from the drainage unit 55. When the bubbles are released from the deodorizing treatment liquid in which the bubbles have been mixed by mixing the vapor and liquid in the gas-liquid mixing portions 58b and 58d, it is easy to fire. Therefore, the upstream side of the weir 59e is partitioned by the partition wall 59d so that the foam does not reach the space above the gas-liquid mixing section 58d, and the firing is performed exclusively on the downstream side of the partition wall 59d.

FIG. 4 shows a human waste treatment facility 1 incorporating a fermentation deodorization system.
The human waste treatment facility 1 includes a pre-treatment facility 2 that receives the human waste and the septic tank sludge that have been carried in to perform pre-treatment, a biological treatment facility 3 that purifies the pre-treated human waste and the like by biological treatment, and after biological treatment. The post-treatment equipment 4 for post-treating the water to be treated into a state suitable for discharge and the sludge treatment equipment 5 for treating surplus sludge and the like generated by biological treatment and the like.

  The pretreatment facility 2 includes a receiving tank 2A, a storage tank 2C, and a preliminary storage tank 2D, and a pretreatment device 2B is installed between the receiving tank 2A and the storage tank 2C.

  Sewage such as human waste that has been carried in by a human waste collection vehicle, etc. is first put into the receiving tank 2A and sent to the pretreatment device 2B while the solid material is crushed by the pump with a cutter, and then the waste residue which is not suitable for biological treatment. After the solid foreign matter is removed by the pretreatment device 2B, it is stored in the storage tank 2C or the preliminary storage tank 2D provided as a spare.

  Then, the wastewater stored in the storage tank 2C is sent to the biological treatment facility 3 by a pump. In the biological treatment facility 3, for example, a deep reaction tank 3A, a nitrification tank 3B, a secondary denitrification tank 3C, and a returning sludge tank 3E are installed in order.

  The wastewater sent from the storage tank 2C is first guided to the deep reaction tank 3A. The deep-layer reaction tank 3A is a biological treatment tank having a depth of about 10 m, and a circulation pump tank 3a is continuously provided above the biological treatment tank. A part of the dirty water pumped out from the circulation pump tank 3a is circulated and supplied to the deep reaction tank 3A, and an ejector mechanism is incorporated in the circulation path to supply air together with the circulated waste water.

  A valve is installed in the air supply path communicating with the ejector mechanism, and the amount of air supplied together with the circulating wastewater is adjusted by periodically controlling the opening of the valve, which is suitable for denitrification in the deep reaction tank 3A. The anoxic state and the aerobic state suitable for nitrification treatment can be switched at intervals of several hours. For example, the valve is opened and closed so that the anaerobic treatment for 1 hour and the aerobic treatment for 2 hours are repeated, and the anaerobic treatment and the aerobic treatment are repeated in a cycle of 3 hours.

  The deep-layer reaction tank 3A has a high water pressure near the bottom of the tank and has a high oxygen-dissolving efficiency, which enables highly efficient treatment. Therefore, it is not necessary to supply dilution water even if the inflow of dirty water is high. That is, the deep-layer reaction tank 3A functions as a nitrification denitrification treatment device.

  The sewage treated by repeating the anaerobic treatment and the aerobic treatment in the deep reaction tank 3A is then transferred to the nitrification tank 3B and nitrified. In the nitrification tank 3B maintained in an aerobic state, ammonia is nitrified by aerobic microorganisms, that is, decomposed into nitrate ions and nitrite ions.

  The wastewater that has been nitrified in the nitrification tank 3B is supplied to the secondary denitrification tank 3C. In the secondary denitrification tank 3C which is maintained in an anaerobic state, denitrification treatment, that is, nitrate ions and nitrite ions are reduced to nitrogen by anaerobic microorganisms and deaerated.

  The wastewater that has been denitrified in the secondary denitrification tank 3C is then transferred to the membrane separation tank 3D. The membrane separation device 3F is immersed and installed in the membrane separation tank 3D, and the sewage in the tank is sucked by a pump connected to the membrane separation device 3F, and the water to be treated that has been solid-liquid separated by the membrane separation device 3F is Water is sent to the post-treatment facility 4.

  The post-treatment facility 4 is provided with a mixing tank 4A, a flocculation tank 4B and a flocculation membrane separation tank 4C. In the water to be treated which has been subjected to solid-liquid separation by the membrane separation device 3F, colloidal fine floating substances remain without being solid-liquid separated. Therefore, the water to be treated sent to the post-treatment facility 4 is first added with an iron-based inorganic coagulant and mixed in the mixing tank 4A, and then fed to the coagulation tank 4B whose pH is adjusted by the addition of caustic soda and the like to aggregate. It is processed.

  Then, the membrane is separated in the coagulation membrane separation tank 4C and sent to the advanced processing equipment 6. The water to be treated sent to the advanced treatment equipment 6 has COD and coloring components adsorbed and removed by, for example, activated carbon adsorption treatment, and further sterilized with hypochlorous acid or the like, and then discharged into a river or the like. The coagulated sludge is sent to the sludge treatment facility 5 and treated together with the surplus sludge.

  The sludge accumulated in the membrane separation tank 3D of the biological treatment facility 3 is sent to the return sludge tank 3E, and then a part of it is pumped to the circulation pump tank 3a of the deep reaction tank 3A via the sludge return paths 3b and 3c. The excess sludge is returned and sent to the sludge dewatering facility 5A.

  The sludge return passage 3b is connected to the liquid supply unit 54 of the deodorizing device 50 on the way, and the drainage unit 55 is connected to the sludge return passage 3c. The sludge return passage 3b serves as a liquid supply passage for the returned sludge from the return sludge tank 3E to be sent to the deodorizing device 50 as a deodorizing treatment liquid, and the sludge return passage 3c for returning to the circulation pump tank 3a after the deodorizing treatment serves as a return passage. Ammonia, which is an odorous gas component captured in the deodorizing treatment liquid by the deodorizing device 50, is returned to the deep-layer reaction tank 3A together with the deodorizing treatment liquid for nitrification denitrification treatment.

  The excess sludge sent to the sludge dewatering equipment 5A and the solid content of the septic tank sludge that has been subjected to solid-liquid separation after the pretreatment are dehydrated after adding a coagulant such as an iron-based inorganic coagulant or a polymer coagulant, The dehydrated sludge is put into the fermentation facility 30 as organic sludge.

  The returned sludge with a low ammonia concentration after nitrification and denitrification treatment using microorganisms is supplied to the liquid supply section as a deodorization treatment liquid, so the ammonia component contained in the deodorization target gas is the deodorization treatment liquid. To be fully dissolved.

  After that, the deodorizing treatment liquid is circulated and supplied to the nitrification and denitrification treatment equipment and is subjected to nitrification and denitrification treatment. Therefore, even if ammonia is dissolved in the deodorization treatment liquid, proper nitrification and denitrification treatment is inherently performed. Moreover, since the returned sludge, which is the deodorization treatment liquid that has been heat-exchanged and heated by the deodorization device, is returned to the nitrification denitrification treatment tank, the nitrification denitrification treatment tank is adjusted to a good temperature, especially in winter. The efficiency will be greatly improved.

Hereinafter, another embodiment will be described.
In the above-described embodiment, an example in which a part of the gas to be treated that has been gas-liquid contacted and deodorized by the deodorizing device 50 is circulated and supplied to the upper heating air blowing mechanism via the circulation supply path 28 has been described. A part of the gas to be treated may be circulated and supplied to the lower heating air-blowing mechanism through the circulation supply path, or may be supplied to both the upper heating air-blowing mechanism and the lower heating air-blowing mechanism. Good. When a part of the gas to be processed is circulated and supplied to the heating air blowing mechanism, it is preferable to circulate and supply it to the upper heating air blowing mechanism which has a higher heating temperature than the lower heating air blowing mechanism and is always operating.

  As shown in FIG. 5, the deodorizing device 50 preferably includes a coagulant supply mechanism that adds an iron-based inorganic coagulant to the deodorizing treatment liquid.

  When the sulfur-based odorous gas contained in the deodorizing target gas is gas-liquid mixed with the deodorizing treatment liquid supplied from the liquid supply unit 54 in the gas-liquid mixing units 58b and 58d, the iron-based inorganic material supplied by the coagulant supply mechanism It reacts with the aggregating agent and becomes deposited as insoluble iron sulfide or sulfur, and is trapped in the deodorizing treatment liquid.

  Sulfur-based odorous gas is, for example, a sulfur compound such as hydrogen sulfide, methyl disulfide, methyl sulfide, mercaptan, etc., which is contained in human waste or septic tank sludge and is discharged together with warming gas during fermentation treatment in fermentation equipment. It becomes part of the gas component.

  As an iron-based inorganic coagulant added to the deodorization treatment liquid by the coagulant supply mechanism, a coagulation containing an excess iron-based inorganic coagulant added to the solid-liquid separation liquid of the excess sludge after nitrification denitrification treatment Sludge can also be used, and in that case, it is not necessary to prepare an iron-based inorganic coagulant dedicated to the deodorization treatment device, and the running cost can be further reduced.

  A coagulant feeding unit 61 may be provided above the gas-liquid mixing unit 58b on the upper wall 51a of the deodorizing device 50, and a coagulant supply mechanism for adding the iron-based inorganic coagulant from the coagulant feeding unit 61 may be provided. As a coagulant supply mechanism, it is composed of a tank filled with an iron-based inorganic coagulant such as ferric polysulfate, a supply pipe for supplying the iron-based inorganic coagulant from the tank, and a diaphragm pump capable of adjusting the flow rate. can do. As the iron-based inorganic coagulant, ferric chloride, ferrous sulfate, ferric sulfate, or the like can be used in addition to polyferric sulfide (polyiron).

  A coagulant supply mechanism for adding an iron-based inorganic coagulant to the sludge return passage 3b shown in FIG. 4 may be provided without providing the deodorizing device 50 with the coagulant feeding unit 61.

  A part of the deodorizing target gas from which the odorous gas has been removed by the deodorizing device 50 is deodorized by the medium-concentration deodorizing tower 80 and the activated carbon adsorption tower 90 together with other medium-concentration odors, and is opened to the atmosphere.

  Although the human waste treatment equipment 1 that employs the deep reaction tank 3A for nitrification and denitrification treatment has been described, the biological treatment tank for performing nitrification and denitrification treatment is not limited to the deep reaction tank 3A, and well-known nitrification treatment tanks and denitrification treatment tanks can be used. A nitrogen treatment tank may be provided separately.

  As described above, by the fermentation deodorizing system described above, a fermentation step of fermenting organic sludge in a fermenter and a warm air blowing step of supplying warm air to the fermentation step, and an odor generated in the fermentation step. A fermentation deodorizing method including a deodorizing step of deodorizing gas is performed.

  The deodorizing step includes an air supplying step for guiding a gas to be treated containing odorous gas and steam generated in the fermentation step to an air supplying section, a liquid supplying step for supplying a deodorizing solution, and a deodorizing method introduced in the air supplying step. A gas-liquid mixing step of gas-liquid mixing the target gas and the deodorizing treatment liquid supplied in the liquid supply step to perform a deodorizing treatment, and a drainage step of discharging the deodorizing treatment liquid used for the deodorizing treatment in the gas-liquid mixing step. And an exhaust step of exhausting the gas to be treated that has been deodorized in the gas-liquid mixing step.

Then, a circulation supply process is performed in which at least a part of the gas to be treated exhausted in the deodorizing process is circulated and supplied to the warm air blowing process without cooling.

  In addition, organic sludge contains excess sludge generated in the nitrifying and denitrifying treatment step that biologically treats the liquid content of human waste or septic tank sludge, or the solid content of human waste and septic tank sludge, and the liquid supply step is the nitrifying and denitrifying treatment step. This is a process of supplying the recycled sludge that is circulated and supplied as a deodorizing treatment liquid via a liquid supply path.The draining process returns the deodorizing treatment liquid used for deodorizing treatment in the gas-liquid mixing process to the nitrification denitrifying treatment process. This is the process of returning the product via the road. Further, the deodorizing step includes a coagulant supplying step of adding an iron-based inorganic coagulant to the deodorizing treatment liquid.

  The above-described embodiment is one aspect of the present invention, and the present invention is not limited to the description, and the specific structure, size, material, etc. of each part are appropriately set within the range in which the effects of the present invention are exhibited. It goes without saying that the design can be modified.

1: Human waste treatment facility 10: Fermentation tank 20: Heating and blowing mechanism 21, 23: Blower fan 22, 24: Heater 25: Induction fan 30: Fermentation equipment 100: Fermentation deodorization system

Claims (8)

A fermentation tank for fermenting organic sludge, a heating air-blowing mechanism for supplying heated air to the fermentation tank, and a gas to be treated containing odorous gas and steam discharged from the fermentation tank and a deodorizing treatment liquid. A fermentative deodorizing system comprising a deodorizing device for contacting liquid for deodorizing treatment,
A fermentation deodorization system comprising a circulation supply path for circulating and supplying at least a part of the gas to be treated exhausted from the deodorization device to the warm air blowing mechanism without cooling. The deodorizing device includes an air supply unit that guides a gas to be treated containing odorous gas and water vapor discharged from the fermentation tank , a liquid supply unit that supplies a deodorizing treatment liquid, and a deodorizing target guided from the air supply unit. A gas-liquid mixing section for deodorizing the gas by press-fitting the gas into the deodorizing solution supplied from the liquid supply section, and a draining section for discharging the deodorizing solution used for the deodorizing process in the gas-liquid mixing section, The fermentation deodorization system according to claim 1, further comprising: an exhaust unit that exhausts the gas to be treated that has been deodorized in the gas-liquid mixing unit. Equipped with a nitrification denitrification treatment tank that biologically treats the liquid content of human waste or septic tank sludge,
A liquid supply path for supplying the activated sludge circulated and supplied in the nitrification and denitrification treatment tank as a deodorization treatment liquid to the liquid supply section, and the deodorized activated sludge discharged from the drainage section in the nitrification and denitrification treatment tank. The fermentation deodorization system according to claim 2 , wherein the fermentation deodorization system is configured to include a return path for returning to.   The fermentation deodorizing system according to claim 3, wherein the deodorizing device includes a coagulant supply mechanism that adds an iron-based inorganic coagulant to the deodorizing treatment liquid. A fermentation step of fermenting organic sludge in a fermenter and a heating air blowing step of supplying heated air to the fermentation step, a gas to be treated containing odorous gas and steam generated in the fermentation step, and a deodorizing treatment liquid. A fermentation deodorizing method comprising a deodorizing step of deodorizing by contacting with gas-liquid,
A fermentation deodorizing method comprising a circulation supply step of circulating and supplying at least a part of the gas to be treated exhausted in the deodorizing step to the warm air blowing step without cooling.   The deodorizing step is a gas supplying step of guiding a gas to be treated containing odorous gas and water vapor generated in the fermentation step to a gas supplying section, a liquid supplying step of supplying a deodorizing liquid, and a gas supplying step. The gas-liquid mixing step of gas-liquid mixing the deodorization target gas and the deodorization treatment liquid supplied in the liquid supply step to perform deodorization treatment, and discharging the deodorization treatment liquid used in the deodorization treatment in the gas-liquid mixing step The fermentation deodorization method according to claim 5, comprising a drainage step and an exhaust step of exhausting the gas to be treated deodorized in the gas-liquid mixing step. Equipped with a nitrification and denitrification process that biologically treats the liquid content of human waste or septic tank sludge,
The liquid supply step is a step of supplying return sludge circulated and supplied in the nitrification and denitrification processing step as a deodorization processing solution through a liquid supply path, and the draining step is used for deodorization processing in the gas-liquid mixing step. The fermentation deodorization method according to claim 6, which is a step of returning the used deodorization treatment liquid to the nitrification denitrification treatment step via a return passage. The fermentation deodorizing method according to claim 7, wherein the deodorizing step includes a coagulant supplying step of adding an iron-based inorganic coagulant to the deodorizing treatment liquid.

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