KR101023684B1 - Method for treating organic waste - Google Patents

Abstract

PURPOSE: An organic waste treatment method is provided to partially circulate organic waste fermented by interconnecting an acid fermenter and a methane fermenter, for maintaining the proper pH concentration and the concentration of ammonia. CONSTITUTION: An organic waste treatment method comprises the following steps: fermenting organic waste by supplying the waste to an acid fermenter and a methane fermenter, from a settling tank(S100); storing methane gas generated from the previous step, to a gas storing unit(S200); processing digestive fluid by filtering and degassing, using a bio-reactor(S300); supplying the processed water generated from the bio-reactor to the methane fermenter(S400); and controlling the concentration of ammonia using the processed water.

Description

Method for treating organic waste

The present invention relates to a method for treating organic wastes, and more particularly, to extract methane gas by fermenting organic wastes, and to separate solid-liquid and harmful gases from digestive liquids, and MBR (Membrane Bio Reactor, Bio-reactor). The present invention relates to a method for treating organic waste, which is intended to be treated at.

In general, organic wastes (food waste, livestock waste, etc.) mainly generated from homes, large restaurants, livestock farms, and food processing companies account for most of the amount of waste generated in Korea, and treatment methods are urgently needed.

Incineration and landfill methods are mostly used as a method of treating such organic waste.

Incineration methods require a lot of processing capacity and initial facility investment costs, and when incineration generates a lot of harmful gases.

Conventional landfill facilities are provided with a vertical order wall and embankment along the side circumference and a bottom order layer on the floor. The leachate collection pipe is installed in the bottom drainage layer or the bottom drainage layer is inclined to the sump well so that the leachate generated from the landfill layer enters the leachate collection pipe or the sump. At this time, the leachate temporarily stored in the sump is flowed to a nearby sewage treatment plant through a transfer pipe, purified and discharged.

However, in order to treat the leachate and general domestic sewage of landfill facilities in sewage treatment plants together, a large amount of chemicals must be added to lower the pollutant concentrations before introducing the leachate, which has a more serious pollutant concentration than the domestic sewage treatment plant. Therefore, excessive chemicals have to be added, and due to the large amount of sludge generated by these chemicals, there was a problem that the sludge treatment cost is also increased.

In order to improve these methods, anaerobic digestion treatments including acid fermentation tanks and methane fermentation tanks have been developed and are already in use.

In the acid fermentation tank and methane fermentation tank, methane gas and extinguishing liquid are generated. High-purity methane gas purified from methane gas is used separately as fuel cell and automobile liquefied fuel, and the digestive liquid is purified and discharged through a separate treatment process.

However, the high concentration of ammonia and alkalinity produced during fermentation in acid fermentation tanks and methane fermentation tanks adversely affects digestion.

In addition, the agitation of the organic waste, which relies only on mechanical stirring, has caused a lot of problems in terms of efficiency due to its low agitation performance, and a situation for improving it has to be presented.

In order to solve the above problems, the present invention provides an organic waste treatment method in which an acid fermentation tank and a methane fermentation tank are interconnected to maintain a proper level of pH concentration and ammonia concentration while circulating a part of organic fermentation. There is a purpose.

In addition, part of the treated water finally treated in the bio-reactor is supplied to the methane fermentation tank, so that the excess concentration of ammonia in the methane fermentation tank is returned to an appropriate level to prevent the excessive concentration of ammonia from being toxic to anaerobic microorganisms. Another purpose is to provide an organic waste disposal method.

In addition, it is another object to provide an organic waste treatment method to dehydrate the sludge during the treatment of the digestive liquid to purify the dehydrated liquid again, and to produce the final liquid in the bio-reactor while producing a composite liquid fertilizer raw material.

In addition, it provides an organic waste treatment method in which the organic matter in the methane fermentation tank is formed upward and diagonally by a nozzle additionally installed at the bottom, and the fermentation is promoted by a stirring flow in which clockwise and counterclockwise flows are alternately formed. There is another purpose.

The present invention for achieving the above object, in the method for treating organic waste, the organic waste is fed to the acid fermentation tank and the methane fermentation tank in a storage tank (S100); Methane gas generated in the step of fermenting the organic waste (S100) is stored in the gas storage tank (S200); The digested liquid generated in the step of fermenting the organic waste (S100) is processed and purified and then processed in a Bio-reactor (S300); A part of the treated water treated in the bio-reactor is supplied to the methane fermentation tank in an emergency (S400); and the step (S400) in which a part of the treated water is supplied is part of the treated water that has passed through the bio-reactor. The treated water supply means is supplied to maintain a range of pH concentration and ammonia concentration for the fermentation organic matter in the methane fermentation tank.

Here, the treated water supply means, the measuring sensor is installed in the methane fermentation tank to measure the concentration of ammonia; A treatment water supply line connected to the methane fermentation tank in the treatment water discharge line of the bio-reactor and installed to open and close the supply valve according to the concentration of ammonia measured by the measurement sensor; And a supply pump installed in association with the treatment water supply line to supply the treatment water from the bio-reactor to the methane fermentation tank.

In the step of fermenting the organic waste (S100), a portion of the organic material being fermented in the methane fermentation tank is circulated to the acid fermentation tank through the second circulation line to maintain pH 4.0 to 4.5.

In addition, in the step of fermenting the organic waste (S100), the acid fermentation liquor is supplied to the lower portion of the methane fermentation tank through a first circulation line connected to the vortex generation means installed in the lower portion of the methane fermentation tank in the acid fermentation tank.

Here, the vortex generating means is installed in the lower portion of the methane fermentation tank and the acid fermentation liquid supplied from the first circulation line is introduced into the first nozzle tube or the second nozzle tube connected to the first circulation line, and the first and second nozzle tubes are respectively introduced. The organics are sprayed in the diagonally upward direction by the installed first nozzle or the second nozzle.

At this time, when the acid fermentation liquid is alternately supplied to the first nozzle tube and the second nozzle tube by the peristaltic valve installed in the first circulation line, the anaerobic digestion liquid in the methane fermentation tank is clockwise by alternating injection of the first nozzle and the second nozzle. And vortices formed counterclockwise alternately.

Anaerobic digestion is circulated internally through an internal circulation line connected to the first circulation line at the top of the methane fermentation tank.

The acid fermentation solution of the acid fermentation tank is agitated by a first stirrer configured to operate the first stirring wing by the first stirring motor, and the anaerobic digestion solution of the methane fermentation tank is operated by the second stirring motor to operate the second stirring blade. It is stirred by a stirrer.

In the step of storing the gas (S200), the methane gas generated in the acid fermentation tank and the methane fermentation tank is desulfurized in a desulfurization facility and then stored in a gas storage tank, and provided for gas purification.

The step (S300) of processing the digestion liquid includes: temporarily storing the digestion liquid generated in the acid fermentation tank and the methane fermentation tank in a stabilization tank installed integrally with the gas storage tank (S310); Digestion liquid discharged from the stabilization tank is separated into a solid-liquid separation liquid and concentrated water in the UF solid-liquid separation membrane tank (S320); While the solid-liquid separation liquid discharged from the UF solid-liquid separation membrane tank is temporarily stored in the solid-liquid separation tank and the carbon dioxide degassing tank and maintained at 45-50 ° C., the carbon dioxide is degassed by strong stirring, and the pH of the solid-liquid separation liquid is raised to 8.0-8.5. Step S330; The solid-liquid separation liquid discharged from the solid-liquid separation liquid storage tank and the carbon dioxide degassing tank is heated to 60 to 80 ℃ by a heat exchanger (S340); The solid-liquid separation liquid heated by the heat exchanger to produce a composite liquid fertilizer raw material while degassing ammonia in the ammonia degassing tank (S350); Removing phosphorus (P) from the fast agglomeration sedimentation tank without adjusting the pH by the ammonia treatment water discharged from the ammonia degassing tank (S360); The supernatant discharged from the high-speed flocculation settling tank is supplied to the bio-reactor for biological treatment and discharge (S370); And sludge generated in the methane fermentation tank, the stabilization tank, and the high speed flocculation settling tank is dehydrated by the centrifugal dehydrator, and the dehydration liquid is reflowed into the solid-liquid separation tank and the carbon dioxide degassing tank (S380).

In the separation step of the UF solid-liquid separation tank (S320), 10-20% of the concentrated water is supplied to the acid fermentation tank through the concentrated water discharge line installed in the UF solid-liquid separation membrane tank to maintain an operating pH of 4.0-4.5 in the acid fermentation tank. 50-60% is supplied to a methane fermentation tank.

In the ammonia degassing step (S350) of the ammonia degassing tank, the pH of the digested filtrate from which the carbon dioxide was degassed first is increased to 8.5 due to strong stirring of the digested liquid filtered in the UF solid-liquid separation membrane tank. In addition, by raising the filtrate water temperature to a maximum of 80 ℃ lowering the ammonia pKa to 8.1 or less, by degassing more than 50% of ammonia without the injection (NaOH) to lower the ammonia and alkalinity in the ammonia treatment water, high speed without pH adjustment by acid injection It is fed to the coagulation sedimentation tank.

The supernatant discharged from the fast flocculation settling tank in the step of purifying and filtering the digested liquid is distributed and supplied to the anaerobic tank and the anoxic tank of the bioreactor within the range of 8: 2 to 6: 4.

As described above, according to the present invention, the part of the organics being fermented in the acid fermentation tank and the methane fermentation tank is circulated with each other, so that the acid fermentation is introduced into the acid fermentation tank to adjust the pH concentration to a certain range, The fermentation broth is introduced to promote fermentation.

In addition, when the ammonia concentration of the methane fermentation tank is measured and the ammonia concentration exceeds a certain range, a portion of the treated water finally treated in the bio-reactor flows into the methane fermentation tank, so that the anaerobic microorganisms in the methane fermentation tank are not toxic to the ammonia. There is an effect that the concentration is adjusted to return to within a certain range.

In addition, carbon dioxide degassing in the process of digestion liquid, the temperature of the digestion filtrate is increased by the effect of obtaining a composite liquid fertilizer raw material in the process of degassing ammonia and economic effect of reducing the acid cost.

In addition, the concentrated water generated while the digestion liquid is treated in the solid-liquid separation membrane tank is re-introduced into the acid fermentation tank and the methane fermentation tank, thereby adjusting the pH and ammonia concentrations.

In addition, there is an effect that the fermentation of organic matter in the methane fermentation tank is promoted by a stirring flow in which clockwise and counterclockwise flows are alternately formed while being upward and diagonally formed by a nozzle installed at the bottom of the methane fermentation tank.

1 is a block diagram showing a method for treating organic waste according to a preferred embodiment of the present invention,
FIG. 2 is a block diagram illustrating a specific filtration step and a treatment step in the step S300 of treating the digestion liquid in FIG. 1.
3 is a configuration diagram schematically showing a processing system according to the processing method of FIG. 1,
4 is a front view schematically showing the inside of the methane fermentation tank shown in FIG.

Hereinafter, a method for treating organic waste according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing a method of treating organic waste according to a preferred embodiment of the present invention, Figure 2 is a block diagram showing a specific filtration and treatment step in the step (S300) in which the digestive fluid is treated in Figure 1, 3 is a configuration diagram schematically showing a treatment system according to the treatment method of FIG. 1, and FIG. 4 is a front view and a perspective view schematically showing the inside of the methane fermentation tank shown in FIG. 3.

First, the organic waste treatment method according to a preferred embodiment of the present invention, as shown in Figure 1 to 4, the organic waste is supplied from the storage tank 100 fermentation in the acid fermentation tank 110 and methane fermentation tank 120 The step (S100), the methane gas generated in the step (S100) of the organic waste fermentation is stored in the gas storage tank 140 (S200), and the digestion liquid generated in the step (S100) of the organic waste is fermented After filtration and degassing, the biological treatment and discharge from the bio-reactor 230 (S300), and the step (S400) of supplying a portion of the treated water from the bio-reactor 230 to the methane fermentation tank 120 It is included.

In the step of fermenting the organic waste (S100), the acid fermentation liquid of the acid fermentation tank 110 is supplied to the methane fermentation tank 120 through the first circulation line 122 in which the first circulation pump 121 is installed, and the methane fermentation tank 120 Anaerobic digestion of the methane fermentation tank 120 is supplied to the acid fermentation tank 110 through the second circulation line 127 in which the second circulation pump 128 is installed. Therefore, the pH concentration of the acid fermentation tank 110 is maintained in the range of 4.0 to 4.5, further decomposition of organic matter proceeds in the methane fermentation tank 120 to increase the amount of gas generated. In addition, the decomposition of organic matter proceeds in the acid fermentation tank 110 to generate methane gas.

Here, the circulation line 122 is connected to the vortex generating means installed in the lower portion of the methane fermentation tank 120, and the acid fermentation liquid is supplied to the lower portion of the methane fermentation tank 120 through the circulation line 122.

As shown in FIG. 4, the organic flow in the vortex generating means is a first nozzle tube connected to the first circulation line 122 while the acid fermentation solution supplied from the first circulation line 122 is installed under the methane fermentation tank 120. 123 or flows into the second nozzle pipe 124. Thereafter, the first nozzle 123a or the second nozzle 124a respectively installed in the first and second nozzle pipes 123 and 124 is sprayed upward and diagonally. At this time, the injection angle θ is preferably 30 to 45 °.

In addition, the acid fermentation liquid is alternately supplied to the first nozzle pipe 123 and the second nozzle pipe 124 by the peristaltic valve 122a provided in the circulation line 122. Therefore, the clockwise and counterclockwise vortices are alternately formed by alternating injection of the first nozzle 123a and the second nozzle 124a, and the anaerobic digestion liquid in the methane fermentation tank 120 is stirred by the vortices.

In addition, the internal circulation line 125 installed above the methane fermentation tank 120 is connected to the first circulation line 122 located below the methane fermentation tank 120 to circulate the anaerobic digestion liquid to internally stir in the methane fermentation tank 120. By increasing the contact efficiency of the organic matter and microorganisms in methane fermentation is increased. Of course, the acid fermentation tank 110 is also preferably provided with a separate internal circulation line to cause internal circulation.

In addition, the acid fermentation solution of the acid fermentation tank 110 is stirred by the first stirrer 111 to operate the first stirring blade 111b by the first stirring motor 111a, the anaerobic digestion liquid of the methane fermentation tank 120 Is stirred by the second stirrer 126 configured to operate the second stirring blade 126b by the second stirring motor 126a. At this time, one or two or more second stirring blades 126b may be installed. Here, the acid fermentation tank 110 can also be circulated to the upper upper fermentation solution by a separate circulation line connected from the top to the bottom.

In the step S200 of storing the gas, the methane gas produced in the acid fermentation tank 110 and the methane fermentation tank 120 is desulfurized in the desulfurization facility 130 and then stored in the gas storage tank 140. The gas of the gas storage tank 140 is a gas purification 150 to be biogas, and some purified biogas is a boiler for providing heat to the heaters 110a and 120a installed in the methane fermentation tank 120 and the acid fermentation tank 110. Supplied to 160. Here, the heaters 110a and 120a heat the temperature in the acid fermentation tank 110 and the methane fermentation tank 120 to 55 ± 1 ° C. This is to maximize the mixing and fermentation in the acid fermentation tank 110 and methane fermentation tank 120 by lowering the viscosity of the organic waste containing a large amount of oil.

On the other hand, in the step (S300) of the digestion liquid generated in the step (S100) of the organic waste fermentation, the digestion liquid produced in the acid fermentation tank 110 and the methane fermentation tank 120 is installed integrally with the gas storage tank 140. Temporarily stored in the stabilization tank 170 (S310), and the digestion liquid discharged from the stabilization tank 170 is separated into a solid-liquid separation liquid and concentrated water in the UF solid-liquid separation membrane tank (S320), UF solid liquid The solid-liquid separation liquid discharged from the separation membrane tank 180 is temporarily stored in the solid-liquid separation liquid storage tank and the carbon dioxide degassing tank 190 to discharge carbon dioxide (S330), and discharged from the solid-liquid separation liquid storage tank and the carbon dioxide degassing tank 190. The solid-liquid separation solution is heated to 60 to 80 ° C. by the heat exchanger 200 (S340), and the heated solid-liquid separation liquid is ammonia depleted without a chemical (NaOH) injection for pH adjustment in the ammonia degassing tank 210. Degassing produces complex liquid fertilizer raw materials Step of reducing the monia and alkalinity (S350) and the step of removing phosphorus (P) from the ammonia treatment water discharged from the ammonia degassing tank 210 without the pH adjustment by a separate acid injection ( S360), the step of discharging the supernatant discharged from the high-speed flocculation settling tank 220 and biological treatment in the bio-reactor 230 (S370), the methane fermentation tank 120 and the stabilization tank 170 and the high-speed flocculation settling tank 220 Sludge generated in the) is dehydrated by the centrifugal dehydrator 240 and the dehydration liquid is reflowed into the solid-liquid separation tank and the carbon dioxide degassing tank 190 (S380).

In step S320 of separating the UF solid-liquid separation membrane tank 180, the concentrated water generated in the UF solid-liquid separation membrane tank 180 is introduced into the acid fermentation tank 110 and the methane fermentation tank 120 through the concentrated water discharge line 181. . Here, 10 to 20% of the concentrated water is introduced into the acid fermentation tank 110 to maintain a pH of about 4.0 to 4.5 in the acid fermentation tank 110 without the addition of sodium hydroxide. In addition, 50 to 60% of the concentrated water is introduced into the methane fermentation tank 120, mixed with the organic matter circulated from the upper portion of the methane fermentation tank 120 is preferably introduced into the lower portion of the methane fermentation tank 120. At this time, the organic matter circulated from the upper side to the lower side of the methane fermentation tank 120 is quantitatively supplied about 6 to 8 times the circulation amount about 12 times a day. Therefore, the concentrated water reduces the amount of sludge flowing out of the methane fermentation tank 120 while increasing the amount of methane gas generated as a fermentation accelerator and the decomposition of residual organic matter in the methane fermentation tank 120. The remaining concentrated water is introduced into the stabilization tank 170 to undergo a separate treatment process.

Here, the operation method of the UF solid-liquid separation membrane tank 180 is a method of operating the system using the membrane device presented in the "filtration system and operation method of the membrane-bound anaerobic digester (Registered Patent No. 0969501) filed by the present applicant. Among the relevant techniques it is good to apply.

Therefore, in the step of temporarily storing in the solid-liquid separation tank and carbon dioxide degassing tank 190 (S330), the solid-liquid separation liquid supplied from the UF solid-liquid separation membrane tank 180 and the dehydration liquid supplied from the centrifugal dehydrator 240 are stored. do. These solid-liquid separation liquid and dehydration liquid are maintained at 45-50 degreeC, carbon dioxide is degassed by strong rapid stirring, and pH rises to 8.0-8.5. Hereinafter, for the sake of convenience, a liquid mixed with a solid liquid separation liquid and a dehydration liquid is collectively referred to as a solid liquid separation liquid.

In step S340 in which the carbon dioxide is degassed, the temperature of the solid-liquid separation liquid is raised by the heat exchanger 200, the temperature of the solid-liquid separation liquid is raised to 60 to 80 ° C, preferably 60 ° C. This is because the ammonia pKa (acid dissociation constant) is lowered to 8.28 due to the increase in water temperature, so that ammonia can be degassed in the ammonia degassing tank 210 without adding sodium hydroxide at a high temperature, and the alkalinity of the solid-liquid separation liquid is also lowered. In the conventional ammonia degassing method, sodium hydroxide must be added to maintain the pH at about 10.5, so that ammonia is degassed. In addition, since the pH of the treated water is about 8.5 after ammonia treatment, the pH of the treated water had to be lowered to 7 to 7.5 by injecting acid such as sulfuric acid. In order to improve this problem, the solid-liquid separation liquid from which carbon dioxide was degassed is heated to a constant temperature.

In the ammonia degassing and production of the composite liquid fertilizer raw material (S350), the solid-liquid separation liquid heated by the heat exchanger 200 flows into the ammonia degassing tank 210 to degas the ammonia, thereby producing a composite liquid fertilizer raw material. At this time, the ammonia is degassed without the injection of a separate drug (NaOH) for adjusting the pH of the solid-liquid separation solution to produce a composite liquid fertilizer raw material, ammonia and alkalinity is reduced. Here, the method for degassing ammonia in the ammonia degassing tank 210 and producing a composite liquid fertilizer raw material is a liquid fertilizer manufacturing method through the ammonia degassing technique of a high concentration of ammonia-containing wastewater, and the apparatus and a device Ammonia degassing apparatus and method shown in " Liquid Fertilizer (Patent No. 0886533) "

In the step S360 in which phosphorus (P) is removed from the high-speed flocculation settling tank 220, phosphorus is removed without pH adjustment by a separate acid injection for the ammonia treated water discharged from the ammonia degassing tank 210. This is because the solid-liquid separation liquid is heated and processed by the heat exchanger 200 at a high temperature.

In step S370 of biological treatment and discharge from the bio-reactor 230, the supernatant discharged from the high-speed flocculation settling tank 220 is treated. In this case, the bio-reactor 230 includes an anaerobic tank 231, an anaerobic tank 232, an aerobic tank 233, and a membrane separation tank 234.

In the anaerobic tank 231, a role of a degassing tank for degassing dissolved oxygen of the returned supernatant and the return sludge returned from the membrane separation tank 234, and release of phosphorus.

The anoxic tank 232 generates a denitrification reaction on the introduced supernatant to convert nitrate nitrogen in the supernatant into nitrogen gas and release it into the atmosphere.

In the aerobic tank 233 and the membrane separation tank 234, nitrification and organic matter oxidation reactions are generated for the supernatant water passing through the anaerobic tank 231 and the anoxic tank 232, and the microorganism, treated water, and sludge are solid-liquid separated.

Here, the supernatant discharged from the high speed flocculation settling tank 220 is distributed and supplied to the anaerobic tank 231 and the anoxic tank 232, and the ratio is distributed and supplied at a ratio of 8: 2 to 6: 4. This is to improve the disadvantage that when the total amount of the supernatant is supplied to the anaerobic tank 231, the treatment efficiency of the anaerobic tank 231 is reduced due to excessive load and the denitrification effect in the anaerobic tank is lowered.

In the sludge dehydration step (S380), sludge generated in the methane fermentation tank 120, the stabilization tank 170, and the high-speed flocculation settling tank 220 are collected together and dehydrated by a centrifugal dehydrator 240 to generate a dehydration cake. The dehydration generated at this time is introduced into the solid-liquid separation tank and the carbon dioxide degassing tank 190. Here, when a predetermined amount of sludge flows in, it is continuously dehydrated, and the dehydration liquid is continuously introduced into the solid-liquid separation tank and the carbon dioxide degassing tank 190 again. In addition, the dehydrated cake is treated separately.

On the other hand, in the step (S400) of supplying a portion of the treated water treated in the bio-reactor 230, a portion of the treated water passing through the bio-reactor 230 to the methane fermentation tank 120 through the treated water supply means Supplied. Therefore, the ammonia concentration of the anaerobic digestion liquid in the methane fermentation tank 120 maintains a certain range to prevent the effect of ammonia toxicity. At this time, the adjustment of the ammonia concentration of the methane fermentation tank 120 by the treated water is made under the situation cooperative with the supply of concentrated water provided to the acid fermentation tank 110 and the methane fermentation tank 120 in the UF solid-liquid separation membrane tank 180. Therefore, the supply of the treated water treated in the bio-reactor 230 is made only in an emergency in which the effect of ammonia toxicity appears in the methane fermentation tank 120 even in the circulating organic matter and the supply of concentrated water.

In addition, in the treated water supply means, the ammonia concentration is continuously measured by the measurement sensor 310 installed in the methane fermentation tank (120). According to this measurement, the treated water supply line 300 branched from the treated water discharge line 250 of the bio-reactor 230 is opened by the supply valve 320, and the treated water is supplied to the methane fermentation tank 120. At this time, the treated water is flowed by the supply pump 330 installed in conjunction with the treated water supply line (300).

Hereinafter, the organic waste treatment method according to a preferred embodiment of the present invention will be described based on the process sequence.

First, the organic waste stored in the storage tank 100 flows into the acid fermentation tank 110 and is acid fermented, and the organic waste is circulated and supplied to the methane fermentation tank 120 circulated with the acid fermentation tank 110 to extract methane gas. At this time, the daily inflow of organic waste is automatically introduced into the acid fermentation tank 110 uniformly over 12 times, and a certain amount is uniformly supplied 12 times from the acid fermentation tank 110 to the methane fermentation tank 120. Here, the acid fermentation tank 110 is stirred by the stirrer and internal circulation so that the oil in the acid fermentation tank 110 is completely mixed, and in the methane fermentation tank 120, the organic material is stirred by the stirrer 126 and the vortex generation means. As the stirring performance is improved, the fermentation reaction is promoted.

The methane gas generated in the acid fermentation tank 110 and the methane fermentation tank 120 is desulfurized in the desulfurization facility 130 and then stored in the gas storage tank 140. Subsequently, the methane gas of the gas storage tank 140 is separated from the high purity desulfurization, dehumidification and desiloxane, and carbon dioxide through the gas purification 150, and partly provided to the boiler 160, and partly provided to the power system by a fuel cell or liquefied. Is then provided with fuel to the car.

The digestion liquid produced in the acid fermentation tank 110 and the methane fermentation tank 120 is stored in the stabilization tank 170 and is kept in a solid state without being precipitated while being stirred, and then flows into the UF solid-liquid separation membrane tank 180, and this UF solid-liquid separation membrane The tank 180 is separated into a solid-liquid separation liquid and concentrated water. 10-20% of the concentrated water is supplied to the acid fermentation tank 110 and 50-60% is supplied to the methane fermentation tank 120 through the concentrated water supply line 181 installed in the UF solid-liquid separation membrane tank 180. Therefore, the pH of the acid fermentation tank 110 is maintained at 4.0 to 4.5, and further decomposition of organic matter occurs in the methane fermentation tank 120, thereby increasing the amount of gas generated.

The solid-liquid separation liquid passing through the UF solid-liquid separation membrane tank 180 is introduced into the solid-liquid separation liquid storage tank 100 so that carbon dioxide is degassed by strong rapid stirring. At this time, the degassing of the carbon dioxide proceeds until the solid-liquid separation liquid is raised to pH 8.5.

The solid-liquid separation liquid from which carbon dioxide is degassed is heated to 60 to 80 ° C. by the heat exchanger 200, and then supplied to the ammonia degassing tank 210. At this time, the increase in water temperature enables ammonia degassing by the ammonia degassing tank 210 without introducing sodium hydroxide, and the alkalinity is also reduced.

The ammonia-treated water in the ammonia degassing tank 210 is introduced into the high-speed agglomeration settling tank 220 to remove phosphorus (P) by coagulation and precipitation, and the supernatant from which phosphorus (P) is removed is bio-reactor (230). Flows into. At this time, the supernatant is distributed and supplied to the anaerobic tank 231 and the anaerobic tank 232 of the bio-reactor 230 in an 8: 2 to 6: 4 ratio.

On the other hand, the sludge generated in the acid fermentation tank 110, stabilization tank 170 and high-speed flocculation settling tank 220 is dewatered in the centrifugal dehydrator (240) 0) and then separated into a dehydration liquid and a dehydration cake, the dehydration liquid is separated into a solid solution Is introduced into the liquid reservoir and carbon dioxide degassing tank 190, the dehydration cake is treated separately.

In addition, the treated water discharged from the bio-reactor 230 is mostly discharged through the treated water discharge line 250, and some treated water is supplied when the ammonia concentration of the methane fermentation tank 120 is out of a predetermined range.

As described above, those skilled in the art will understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features. It is therefore to be understood that the above-described embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

100 ... storage tank 110 ... acid fermentation tank,
120 methane fermentation tank 122 first circulation line,
130 desulfurization plant 140 gas storage tank,
170.stabilization tank 180 ... UF solid-liquid separation membrane tank,
190.Solid-liquid separation tank and carbon dioxide degassing tank 200 ... heat exchanger,
210 ammonia degasser 220 high speed coagulation precipitator
230 ... Bio-reactor 240 ...
300 ... treated water supply line 310 ... measuring sensor.

Claims (17)

In the method of treating organic waste,
The organic waste is supplied to the acid fermentation tank 110 and the methane fermentation tank 120 in the storage tank 100 is fermented (S100);
Methane gas generated in the step of fermenting the organic waste (S100) is stored in the gas storage tank 140 (S200);
Digesting liquid generated in the step of fermenting the organic waste (S100) is filtered and degassed and then treated in the Bio-reactor 230 (S300);
A part of the treated water treated in the bio-reactor 230 is supplied to the methane fermentation tank 120 (S400);
In step S400, a portion of the treated water that has passed through the bio-reactor 230 is supplied through the treated water supply means to supply a portion of the treated water to provide ammonia concentration to the anaerobic digestion liquid in the methane fermentation tank 120. Organic waste treatment method characterized in that maintained within a predetermined range. The method of claim 1,
The treated water supply means is a concentration of ammonia is measured by a measuring sensor 310 installed in the methane fermentation tank 120,
The treatment water supply line 300 connected to the methane fermentation tank 120 from the treatment water discharge line 250 of the bio-reactor 230 is provided by the supply valve 320 based on the measurement value of the measurement sensor 310. When opened, the supply pump (330) is operated to process the organic waste, characterized in that a portion of the treated water is supplied to the methane fermentation tank (120). The method of claim 1,
In the step of fermenting the organic waste (S100), a portion of the anaerobic digestion of the methane fermentation tank 120 is connected to the acid fermentation tank 110 and the methane fermentation tank 120 through the second circulation line 127 through the acid fermentation tank. Organic waste treatment method characterized in that the circulation to (110) is maintained at pH 4.0 to 4.5. The method of claim 3,
In the step of fermenting the organic waste (S100), the acid fermentation solution of the acid fermentation tank 110 through the first circulation line 122 connected to the vortex generation means installed in the methane fermentation tank 120 in the acid fermentation tank 110 Organic waste treatment method characterized in that it is supplied to the lower portion of the methane fermentation tank (120). The method according to claim 1 or 3,
In the step of fermenting the organic waste (S100), the anaerobic digestion of the methane fermentation tank 120 is the acid fermentation tank 110 through a second circulation line 127 connected from the methane fermentation tank 120 to the acid fermentation tank 110. Organic waste treatment method characterized in that the cycle. The method of claim 4, wherein
The vortex generation means is installed in the lower portion of the methane fermentation tank 120, when the acid fermentation solution flows into the first nozzle pipe 123 or the second nozzle pipe 124 connected to the first circulation line 122, Organic waste treatment method characterized in that the first nozzle (123a) or the second nozzle (124a) installed in the first and second nozzle pipes (123, 124) are sprayed in an upward diagonal direction. The method of claim 6,
Acid fermentation liquid is alternately supplied to the first nozzle pipe (123) and the second nozzle pipe (124) by the peristaltic valve (122a) installed in the first circulation line (122). The method of claim 6,
The anaerobic digestion liquid in the methane fermentation tank 120 is agitated by vortices alternately clockwise and counterclockwise by alternating injection of the first nozzle 123a and the second nozzle 124a. Way. The method of claim 4, wherein
Organic waste treatment method characterized in that the anaerobic digestion liquid is internally circulated through the internal circulation line 125 connected to the first circulation line 122 in the methane fermentation tank (120). The method of claim 1,
The acid fermentation solution of the acid fermentation tank 110 is organic waste treatment method characterized in that the first stirring blade (111a) by the first stirring blade (111b) is operated by the first stirrer (111). The method of claim 1,
Anaerobic digestion of the methane fermentation tank (120) is an organic waste treatment method characterized in that the stirring by the second stirrer (126) made to operate the second stirring blade (126b) by the second stirring motor (126a). The method of claim 1,
The methane gas generated in the acid fermentation tank 110 and the methane fermentation tank 120 is stored in the gas storage tank 140 after the desulfurization treatment in the desulfurization plant 130 in the step of storing the gas (S200). Organic waste treatment method, characterized in that provided for (150). The method of claim 1,
The step of processing the digestive fluid (S300),
The extinguishing liquid generated in the acid fermentation tank 110 and the methane fermentation tank 120 is temporarily stored in a stabilization tank 170 installed integrally with the gas storage tank 140 (S310);
Separating the digestion liquid discharged from the stabilization tank 170 into the solid-liquid separation liquid and the concentrated water in the UF solid-liquid separation membrane tank 180 (S320);
The solid-liquid separation liquid discharged from the UF solid-liquid separation membrane tank 180 is temporarily stored in the solid-liquid separation liquid storage tank and the carbon dioxide degassing tank 190 and stirred while being maintained at 45-50 ° C. to degas the carbon dioxide, and the pH of the solid-liquid separation liquid is Rising to 8.0 to 8.5 (S330);
The solid-liquid separation liquid discharged from the solid-liquid separation liquid storage tank and the carbon dioxide degassing tank 190 is heated to 60 to 80 ° C. by the heat exchanger 200 to decrease pKa (S340);
The solid-liquid separation liquid heated by the heat exchanger 200 is a mixed liquid fertilizer raw material is produced while ammonia is degassed in the ammonia degassing tank 210 without a separate injection (NaOH) (S350);
Removing ammonia treated water discharged from the ammonia degassing tank 210 and removing phosphorus (P) from the fast agglomeration settling tank 220 without adjusting pH by acid injection (S360);
A step of supplying the supernatant discharged from the high-speed flocculation settling tank 220 to the Bio-reactor 230 for biological treatment (S370); And
The sludge generated in the methane fermentation tank 120, the stabilization tank 170 and the high speed flocculation settling tank 220 is dewatered by the centrifugal dehydrator 240, the dehydration liquid is the solid-liquid separation tank and carbon dioxide degassing tank 190 Re-introduced to step (S380); organic waste treatment method comprising a. The method of claim 13,
In the separation step (S320) of the UF solid-liquid separation membrane tank 180, 10-20% of the concentrated water is supplied to the acid fermentation tank 110 through the concentrated water discharge line 181 so that the pH in the acid fermentation tank 110 is increased. Organic waste treatment method characterized in that it is maintained at 4.0 to 4.5. The method of claim 13,
In the separation step (S320) of the UF solid-liquid separation membrane tank (180), the organic waste treatment method, characterized in that 50 to 60% of the concentrated water is supplied to the methane fermentation tank 120 through the concentrated water discharge line (181). The method of claim 13,
In the step of purifying and filtering the digestion liquid (S400), the supernatant discharged from the high-speed flocculation settling tank 220 is distributed and supplied to the anaerobic tank 231 and the anaerobic tank 232 of the Bio-reactor 230. Waste treatment method. The method of claim 13,
In the step (S400) of the digestion liquid is purified and filtered, the anaerobic tank 231 and the anaerobic tank 232, the distribution of organic waste treatment method characterized in that made in the range of 8: 2 to 6: 4.

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