KR100592492B1 - Organic waste treatment method using novel sequencing batch thermophilic/mesophilic two-stage anaerobic digestion - Google Patents

Abstract

The present invention relates to a method for treating organic waste using a continuous batch high temperature / mid temperature two-stage anaerobic digestion process. More specifically, a high temperature reactor and a medium temperature in which anaerobic microorganisms including hydrolysis microorganisms, acid-fermenting microorganisms and methane-producing microorganisms are connected in series. The present invention relates to a method for treating organic waste by planting each reactor and maintaining a symbiotic relationship between these anaerobic microorganisms.

The method for treating organic waste using the continuous batch high temperature / medium temperature two-stage anaerobic digestion process of the present invention

(1) introducing organic waste into a high temperature reactor containing anaerobic microorganisms and reacting with the anaerobic microorganisms,

(2) reacting with the anaerobic microorganisms by introducing a supernatant after the step (1) to a mesophilic reactor containing anaerobic microorganisms,

(3) after the step (2) comprises the step of draining the treated organic waste in the medium temperature reaction tank.

Description

Organic waste treatment method using novel sequencing batch thermophilic / mesophilic two-stage anaerobic digestion}             

1 is an example of a system for realizing a continuous batch high temperature / medium temperature two-stage anaerobic digestion process of the present invention.

Figure 2 shows the operation of the organic waste treatment method of the present invention.

Figure 3 is a graph showing the methane generation rate per unit volume after treating the organic waste in the fermentation tank of the continuous batch high temperature / medium temperature two-stage anaerobic digestion process of the Example and the control series system.

Figure 4 is a graph showing the change in organic matter removal efficiency according to the organic load by the continuous batch high temperature / medium temperature two-stage anaerobic digestion process and the control series system.

FIG. 5 is a graph showing methane production of microorganisms using acetate as a substrate in a batch experiment performed on microorganisms collected in a fermentation tank of a continuous batch high temperature / medium temperature two-stage anaerobic digestion process and a control series system.

FIG. 6 is a graph showing methane production of microorganisms using propionate as a substrate in a batch batch high temperature / mid temperature two-stage anaerobic digestion process and a batch experiment conducted on a microorganism collected in a fermenter of a control system series.

7 is a graph showing the methane production of microorganisms using butyrate as a substrate in a batch experiment performed on microorganisms collected in a fermentation tank of a continuous batch high temperature / medium temperature two-phase anaerobic digestion process and a control system of the example.

8 is a COD discharged after hydrolysis when using food waste and sewage sludge as a substrate in a batch batch high temperature / medium temperature two-stage anaerobic digestion process and a batch experiment performed on the microorganisms collected in the fermentation tank of the control series system It is a graph showing the concentration.

<Description of Symbols for Main Parts of Drawings>

1: 1 stage high temperature reactor 2: 2 stage medium temperature reactor

3, 3 ': methane gas 4: agitator control device

5: pump control device 6: temperature control device

7, 8, 9: pump

The present invention relates to a method for treating organic waste using a continuous batch high temperature / mid temperature two-stage anaerobic digestion process. More specifically, a high temperature reactor and a medium temperature in which anaerobic microorganisms including hydrolysis microorganisms, acid-fermenting microorganisms and methane-producing microorganisms are connected in series. The present invention relates to a method for treating organic waste by planting each reactor and maintaining a symbiotic relationship between these anaerobic microorganisms.

Organic wastes such as food waste, sewage sludge, wastewater sludge, agricultural waste, and livestock waste are inevitably occurring in humans' lives.

Organic waste is usually landfilled or incinerated at incinerators. However, organic wastes embedded in landfills are polluting soil by leachate and generate odors. Therefore, it is difficult to obtain landfills and is gradually treating organic wastes mainly for incineration. However, organic wastes are mainly classified as food waste and livestock, and they contain a large amount of water. Therefore, before incineration, organic wastes have good combustion efficiency only when the organic wastes are removed or incinerated before the water content is reduced. However, this method of incineration has a problem that the cost and time of disposal of organic waste increases.

In 2003, a direct ban on landfilling of sewage sludge was implemented. In 2005, food waste was also banned from direct landfilling. Adoption of the 1996 London Amendment Protocol will continue to strengthen regulations on dumping at sea, and therefore appropriate measures for the disposal of organic waste are urgently needed.

In order to solve the problem of disposal of organic waste, each country has developed an optimized approach to the treatment of organic wastewater and waste by combining and applying scientific knowledge and core technologies that are known through the engineering approach to the treatment and disposal of organic waste. An alternative is proposed. However, in order to achieve the effectiveness of organic waste, which is virtually impossible to suppress fundamental generation, it must be accompanied by the development of technology for reducing the volume of organic waste and resource development.

Anaerobic treatment technology among organic waste treatment methods is not limited to the low-efficiency, fully mixed anaerobic treatment process to meet the demands of the times, and is being developed in various forms, and the development of anaerobic systems for more optimized high efficiency treatment is in progress. It is becoming. The biggest advantage of the high efficiency anaerobic process is that it is an economic technology that can produce energy while reducing the final disposal of organic waste by reducing the organic waste and at the same time recovering methane gas, which is a useful energy source from the reduced organic matter, with maximum recovery rate. . In addition, it operates with a short hydraulic retention time (HRT) for the volume of the material to be treated, making it possible to reduce the design volume of the process, thereby enabling more economical treatment.

Representative well-known anaerobic treatment technology is an upflow anaerobic sludge blanket (UASB) (Lettinga, G., Hulshoff-Pol, LW, Wat. Sci.Tech.Vol. 24, 1991, p. 87 -107), two-phase separation (Fox P. and Pohland FG, Wat.Environ.Res. Vol. 66, 1994, p. 716-724), temperature-phase anaerobic digestion phased anaerobic digestion (Han Y., Sung S. and Dague RR, Wat. Sci. Tech. Vol. 36, 1997, p. 367-374), anaerobic sequencing batch reactor (Sung S) and Dague RR, Water Environ.Res. Vol. 67, 1995, p. 294-301), have been reported to have high treatment efficiency and stable operation centering on various wastewater treatments.

For the treatment of organic wastes in the form of slurries having a high solids concentration, most of them are applied to a two-phase anaerobic process for converting liquefied fermentation broth into methane through hydrolysis and acid fermentation. However, even in this case, there is a problem in that the volume of the reaction tank is increased because multi-step treatment is required, such as a hydrolysis reactor, an acid fermentation reactor, and a methane generation reactor.

The present invention has been made to solve the above-mentioned problems, and to provide a method for treating organic waste by achieving an optimized combination of temperature-phase separation anaerobic digestion technology and a continuous batch operation method.

The present invention obtains methane gas through hydrolysis, acid fermentation, and methane fermentation in a high temperature and medium temperature two-stage reactor connected in series using a continuous batch high temperature / medium temperature two-stage anaerobic digestion process, and simultaneously treats organic waste by the above reaction. It aims to provide an organic waste disposal method that can be used as a compost or land improver by stabilizing the final generation of organic waste by maximizing efficiency and stabilizing the organic waste that has undergone the hot / medium two-stage reactor.

The organic waste treatment method using the continuous batch high temperature / medium temperature two-stage anaerobic digestion of the present invention minimizes the problems of existing similar processes and single processes, and complements each other to ensure the optimal operating conditions of anaerobic methane fermentation bacteria sensitive to environmental conditions. By operating characteristics, it is possible to cope more smoothly with changes in temperature, impact load, and microbial activity caused by toxic substances that can occur in actual operation, and can reduce organic waste and maximize methane conversion.

The present invention is to continuously discharge the supernatant after solid / liquid separation by precipitation after attempting continuous contact between methane fermentation bacteria and organic waste substrate in the continuous hydrolysis, acid fermentation and methane fermentation mechanism after the organic waste is put into the reactor The batch reaction is applied to the single stage and two stage reactors.

Among the organic substances introduced into the reactor, the contact time between untreated particles of volatile solids (VS) or hydrolysates or acid fermentation by-products in the reactor and the microorganisms decomposing them is maintained to the maximum to show high efficiency operation and maximize processing efficiency. Can be. In addition, as methane fermentation proceeds in one stage of high temperature reactor, hot methane fermentation bacteria having fast biological metabolism rate are maintained as dominant species to maximize hydrolysis efficiency known as rate-limiting step of general particulate waste. can do. In addition, it has secured the stability of the process against high organic loads, and additionally, it can be used as a compost or land reforming agent because of the pathogen killing effect.

Methane fermentation in a two-stage mid-temperature reactor was followed by subsequent treatment of volatile fatty acids (VFA) contained in the supernatant from the methane fermentation in one-stage high-temperature reactor and temporary deterioration of the effluent of sensitive hot methane fermentation. To ensure that the process remains stable and methane recovery is maintained.

The method for treating organic waste using the continuous batch high temperature / medium temperature two-stage anaerobic digestion process of the present invention

(1) introducing organic waste into a high temperature reactor containing anaerobic microorganisms and reacting with the anaerobic microorganisms,

(2) reacting with the anaerobic microorganisms by introducing a supernatant after the step (1) to a mesophilic reactor containing anaerobic microorganisms,

(3) after the step (2) comprises the step of draining the treated organic waste in the medium temperature reaction tank.

In the present invention, the step (1) is to generate methane gas by the hydrolysis, acid fermentation and methanation reaction by introducing the organic waste into the high-temperature reactor containing hydrolysis microorganisms, acid fermentation microorganisms, methane-producing microorganisms as anaerobic microorganisms It is a step of reducing the content of organic matter.

If step (1) is described in more detail

(a1) a step of introducing organic waste into a high temperature reactor containing hydrolyzed microorganisms, acid-fermenting microorganisms and methane-producing microorganisms as anaerobic microorganisms,

(a2) process of generating methane gas from organic wastes by hydrolysis, acid fermentation and methanation of the introduced organic wastes with anaerobic microorganisms,

(a3) after the step (a2) to precipitate organic waste and anaerobic microorganisms to separate the solid and liquid by gravity,

(a4) includes a step of flowing out the supernatant generated after the solid / liquid separation process of (a3) from the high temperature reaction tank to flow into the middle temperature reaction tank.

In the present invention, the step (2) will be described in detail.

(b1) The organic wastes of the supernatant from the high temperature reactor are anaerobic microorganisms, which are hydrolyzed, acid-fermented and methanated with anaerobic microorganisms in a medium temperature reactor containing hydrolyzed microorganisms, acid-fermenting microorganisms and methane-producing microorganisms. Methane gas generating process,

(b2) separating the solid / liquid by gravity by precipitating organic waste and anaerobic microorganisms after the step (b1);

(b3) after the step (b2) the step of flowing out the supernatant treated with organic waste from the medium temperature reaction tank,

(b4) a step of introducing the supernatant generated from the high temperature reactor after the step (b3) into the medium temperature reactor.

In the treatment of the organic waste of the present invention, the temperature of the high temperature reactor in step (1) is 50 to 55 ° C, and the temperature of the medium temperature reactor in step (2) is 30 to 35 ° C. This is because anaerobic microorganisms have an optimum activity at 50 to 55 ° C. at high temperatures and an optimum activity at 30 to 35 ° C. at medium temperatures.

Meanwhile, the organic waste of the present invention may be any one selected from food waste, sewage sludge, wastewater sludge, agricultural waste, and livestock waste, or a mixture thereof through an anaerobic digestion process of a continuous batch fine / mid temperature two-stage reactor.

In the present invention, anaerobic microorganisms are commonly used in anaerobic digestion, and any hydrolysis microorganism, acid fermentation microorganism, or methane-producing microorganism exhibiting optimal activity at medium temperature (30-35 ° C.) or high temperature (50-55 ° C.) Can also be used. In addition, the sludge of the anaerobic digester which contains these microorganisms and is operated in advance can be used. Hydrolytic fermentative bacteria as an example of the anaerobic microorganisms in the present invention are clostridium species ( clostridium species ), acetivibrio species ( acetivibrio species ), luminococcus spissis ( ruminoccocus species ), bacteroids Any one or two or more selected from microorganisms such as bacteroides species may be used. Acid fermenting microorganism (acidogens) is acetonitrile bakteo speaker system (acetobacter species), Lactobacillus speaker system (lactobacillus species), Streptococcus speaker system (streptococcus speices), Phedi O Lactococcus RY sheath (pediococcus species), propynyl sludge tumefaciens RY cis ( propionibacterium species ), any one selected from among microorganisms, or two or more may be used. Methanogens have been studied in more detail, including: methanobacterium species , methanobrevibacter species , methanospririllum species , and metanopes. Methanoplanus species , methanococcus species , methanosarcina species , methanothrix species , methanothrix species , methanolobus species , Any one selected from methanococcoides species or two or more may be used.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

1 is an example of a system for realizing a continuous batch high temperature / medium temperature two-stage anaerobic digestion process of the present invention.

1 is largely composed of a first stage high temperature reactor 1 and a two stage medium temperature reactor 2 are directly connected to each other, there is a temperature control device 6 to maintain a high temperature in the first stage high temperature reactor.

Inside each reactor 1, 2 there are agitators 14, 14 'for promoting the reaction of organic waste and anaerobic microorganisms, and a controller 4 for controlling the speed of the agitator is each reactor 1 ( 2) It is provided outside. One side of each reactor is provided with a pump (7) (8) (9) and a pump control device (5) for controlling the pump, which can introduce or discharge organic waste into each reactor.

The organic waste (11) is subjected to hydrolysis, acid fermentation and methane fermentation in each reactor (1) (2) while passing through the first stage high temperature reactor (1) and the two stage medium temperature reactor (2) during the in-process residence period. The organics are converted to methane gas (3, 3 '), and the untreated organic particles are precipitated and remain in the reactor together with the anaerobic microorganisms maintained at a high concentration, resulting in small molecular weight particles or continuous liquefaction.

In FIG. 1, reference numeral 10 denotes a water jacket. The outer jacket surrounds the outside of the first stage high temperature reactor 1 so that the first stage high temperature reactor maintains a high temperature by the temperature control device 6. Reference numeral 11 denotes a flow of organic waste flowing into the first stage high temperature reactor. Reference numeral 13 denotes the flow of the supernatant flowing out of the first stage high temperature reactor 1, and reference numeral 13 ′ denotes that the supernatant flowing out of the first stage high temperature reactor by the pump 8 flows into the two stage intermediate temperature reactor 2. Indicate the flow. Reference numeral 12 denotes a flow of organic waste flowing out of the two-stage mid-temperature reactor 2.

2 shows a method for treating organic waste using a continuous batch high temperature / medium temperature two-stage anaerobic digestion process with steps 1 to 5 as an operation process of the method for treating organic waste of the present invention. In this case, the unit of the cycle may be one day or several days to several tens of days.

In step ①, the supernatant of the first stage high temperature reactor 1 is introduced into the second stage medium temperature reactor 2 before the organic waste to be treated is introduced into the first stage high temperature reactor 1 (completed in step ⑤). As the stirring begins at), organic waste is introduced into the first stage high temperature reactor (1). On the other hand, the supernatant of the first stage high temperature reactor (1) introduced into the two stage medium temperature reactor (2) in step ① reacts with the anaerobic microorganisms in the two stage medium temperature reactor (2), and a subsequent methane fermentation reaction occurs.

In steps ② and ③, the first stage high temperature reactor (1) contains proteins, lipoids and biodegradable polymers starting from easily decomposed grains or carbohydrates. Sequential hydrolysis, acid fermentation and methane fermentation continue. Microorganisms showing optimum activity at high temperature (50-55 ℃) and metabolism higher than medium-temperature (30-35 ℃) methane fermentation are maintained as dominant species in the first stage high temperature reactor (1), so that liquefaction to organic acid proceeds rapidly. Even if the organic acid can be converted from the organic acid to methane more quickly without the accumulation of the organic acid it is possible to maintain an optimal pH of 6.5 to 7.5 to ensure the activity of the methane fermentation bacteria. Meanwhile, in step ②, the second stage medium temperature reactor (2) generates methane gas by successive subsequent methane fermentation, and the second stage medium temperature reactor (2) stops stirring and precipitates in step ③, at which point the methane gas generation is completed. It causes solid / liquid separation by gravity.

In step ④, the first stage high temperature reactor (1) stops the agitation of organic waste and anaerobic microorganisms by the completion of methane gas generation, and the active micromass and the untreated organic waste particles are precipitated at the same time to separate solid / liquid by gravity. Happens. At this time, the untreated organic waste particles become particles of small molecular weight or continuously liquefy as they remain in the reactor together with the untreated organic waste particles and anaerobic microorganisms for a long time. In step ④, the two-stage mesothelial reactor 2 flows the supernatant generated by the solid / liquid separation in step ③ to the outside of the two-stage mesothelial reactor.

In step ⑤, the first stage high temperature reactor 1 flows out the supernatant generated by the solid / liquid separation in step ④ to the outside of the first stage high temperature reactor 1 and introduces it into the two stage medium temperature reactor 2. In step ⑤, the two-stage mesothelial reactor 2 introduces the supernatant flowing out of the first stage high-temperature reactor 1 into the two-stage mesothelial reactor 2.

As described above, in the present invention, the two-stage mesothelial reaction tank (2) has the same operation as that of the first-stage high temperature reactor (1), and the difference is that the inflow substrate is the effluent water, which is the supernatant of the high temperature reaction tank. Will be responsible for the post-treatment of untreated organic waste and fine organic particles.

Meanwhile, in the present invention, the organic waste is introduced into the first stage high temperature reactor 1 after removing impurities that cannot react with microorganisms such as plastic, stone, and iron through crushing and sorting. Be sure to At this time, the crushing process and the sorting process can be carried out by a person of ordinary skill in the art to choose appropriate details will be omitted below.

Hereinafter, the content of the present invention will be described in detail through examples and test examples. However, these are intended to explain the present invention in more detail, and the scope of the present invention is not limited thereto.

<Example>

Organic waste was treated in the steps shown in Table 1 below using the system of the continuous batch high temperature / mid temperature two-stage anaerobic digestion process (hereinafter, abbreviated as TPASBR process) as shown in FIG. 1.

In Figure 1, the first stage high temperature reactor (1) and the two stage medium temperature reactor (4) were directly connected to each having an effective volume of 4L, and the first stage reactor was operated at 55 ° C and the two stage reactor at 35 ° C. On the other hand, although not shown in FIG. 1, the system of FIG. 1 additionally includes a feed tank of two organic wastes and two gas collectors connected to the respective reaction tanks 1 and 2. Drive.

As a control, two reactors having an effective volume of 4L were connected in series and operated at medium temperature (35 ° C.) to treat organic waste (hereinafter abbreviated as series system).

Process operation in one cycle from Step 1 to Step 5 in Table 1 is represented. Each reactor (1) and (2) was operated as an inflow process (1 hour), a reaction reaction (17 hours), a precipitation process (5 hours), and an outflow process (1 hour) of organic waste at a cycle of 24 hours. 17 hours of reaction and 5 hours of precipitation, sufficient for hydrolysis, acid fermentation and methane fermentation of organic wastes, is an optimal batch operation for organic wastes that ensures stable methane production and solid / liquid separation. Woo Kim, Sun-Kee Han and Hang-Sik Shin, J. KOWREC Vol. 12, 2004 (In press)].

The anaerobic microorganisms used in the first stage high temperature reactor and the second stage medium temperature reactor in FIG. 1 were collected by planting microorganisms of anaerobic digestion tanks treating primary sludge and secondary sludge in Daejeon sewage treatment plant under Daejeon Metropolitan City Facilities Management Corporation. The substrate is composed of organic waste mixed with primary sludge and waste activated sludge (WAS) in a 50:50 ratio of food waste generated from sewage sludge and general restaurant in Daejeon Metropolitan Sewage Treatment Plant concentration tank. Used. The characteristics of the organic wastes are shown in Table 2 below. On the other hand, organic wastes are preliminarily removed impurities that cannot react with microorganisms such as plastic, stone, and iron through crushing and sorting.

Table 1.

Table 2.

Item unit Sewage sludge Food waste Physical properties TS % 2.4 ~ 3.1 16.1 ~ 21.7 VS % 1.2 ~ 2.0 14.9-20.2 Average VS / TS - 54.9 95.0 Chemical properties Carbon (C) % 24.4 50.1 Nitrogen (N) % 3.4 3.6 Hydrogen (H) % 3.9 6.7 Sulfur (S) % 0.7 - Carbon / Nitrogen (C / N) - 7.2 13.7

<Test Example 1>

After treating the organic waste by the TPASBR process and the control series system of the above embodiment, the change in methane generation rate and organic matter removal efficiency per unit volume was measured and the results are shown in FIGS. 3 and 4, respectively.

The methane generation rate per unit volume ranged from 49% to 62% at standard temperature (STP) in both the first stage high temperature reactor of the TPASBR process and the first reactor of the series system.

The average organic removal efficiency was evaluated at 0.8 to 2.7 g VS / L / d of total organic matter loading. As shown in FIG. 3, the organic matter removal efficiency was very excellent at low organic loading rate (OLR) due to the continuous batch operation. This was possible due to the input of high biodegradable food waste. The average methane production rate for the TPASBR process was 0.41 CH4 / L / d at 2.7 g VS / L / d of organic load. In addition, most of the methane in the examples and the control was produced in a single stage reaction tank, indicating that the main reactor of methane generation was a single stage reaction tank.

VS removal efficiency for the organic load is shown in FIG. As shown in Figure 4 it can be seen that the TPASBR process of the embodiment is superior to the VS removal efficiency compared to the control series system. On the other hand, the TPASBR process of Example showed high VS removal efficiency of 60% or more up to 2.7g VS / L / d of organic matter, and no abnormal symptoms such as washout due to severe VFA accumulation or foaming were observed. .

In the TPASBR process and the control series system of the above embodiment, the gas generated in each reactor is collected in a gas collector, and the gas composition analysis of the gas collector is performed using a Porapak Q TCD column (6 ft x 2 mm stainless steel column) and a helium gas with a transfer gas. It measured using Gow Mac GC (Gas chromatography series 580) used.

<Test Example 2>

The pH for each reactor in the TPASBR process and control series system of the Example was measured by calibrating the pH meter (Orion 720A) with a standard pH solution (pH 4, pH 7).

The pH of the four reactors of the TPASBR process of the Example and the control system series system was about 7.5, and was kept relatively constant. Total alkali was also maintained at 2600-3200 mg / L (as CaCO3) without any significant difference, enabling stable operation even at relatively high organic loads.

<Test Example 3>

In order to evaluate the methane production capacity of the biomass in each reactor of the TPASBR process and the control series system of the example, a specific methanogenic activity test (SMA) was performed to measure the methane production rate by the microorganisms from the precursor of methane. The results are shown in FIGS. 5 to 7. As a substrate, acetate, propionate and butyrate, which are precursors of methane, were used. The concentration of each substrate was adjusted to 2000 mg COD / L and followed by the method of buffer, alkalinity, mineral solution type and concentration Owen et al. (1979).

5 and 7 it can be seen that the high methane production rate of acetate and butyrate. In particular, the metabolic efficiency of acetate with more than 70ml CH4 / gVSS / d is considered to be the Methanosarcina species and Methanothrix species , the predominant species among the microorganisms in the TPASBR process, known as acetoclastic methanogens. . In addition, the rapid metabolism in the high temperature reactor is considered to be due to the increased hydrolysis efficiency which acts as a rate-limiting step in the production of methane from solid waste.

<Test Example 4>

In order to examine the hydrolysis efficiency of Test Example 3, a chemical oxygen demand (COD) emission experiment was performed after hydrolysis of microorganisms in each reactor by a TPASBR process of Example and a series of control systems.

Substrate concentration was adjusted to 5g VS / L, and hydrolysis was carried out in each reactor by adding bromoethane sulfonic acid, which is well known as a methane production inhibitor, at a concentration of 50m mol / L to inhibit methane bacteria activity. COD emitted by was measured using a dichromate reflux method and the results are shown in FIG. 8.

As shown in Figure 8 it can be seen that in the TPASBR process of the embodiment of the present invention has a higher COD concentration, more hydrolysis occurred in the series system of the control. Thus, since the decomposition is much, it can be seen that methane generation after hydrolysis and acid fermentation is also more generated in the TPASBR process of the Example than the control series system.

The organic waste treatment method using the continuous batch high temperature / mid temperature two-stage anaerobic digestion process of the present invention from the results of the above examples and test examples is carried out through the continuous batch operation of the high temperature reactor and the medium temperature reactor through the optimal combination of existing unit technology. By maximizing the volume loss to be disposed of last and converting liquefied organics into methane gas, a useful energy source, bioenergy can be dramatically increased.

In particular, in the waste treatment, it is possible to increase the residence time and microbial contact time of the untreated residue in the reaction tank and reduce the operating cost by rational continuous batch operation.

As described above, although described with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and modified within the scope of the present invention without departing from the spirit and scope of the present invention described in the claims below. It will be appreciated that it can be changed.

Claims (6)

In the treatment of organic waste, (1) reacting with anaerobic microorganisms by introducing organic waste into a high temperature reactor containing anaerobic microorganisms and maintained at 50 to 55 ° C; (2) reacting with the anaerobic microorganisms by introducing a supernatant after the step (1) treatment into a medium temperature reactor containing anaerobic microorganisms and maintained at 30 to 35 ℃; (3) a method for treating organic waste using a continuous batch high temperature / medium temperature two-stage anaerobic digestion process comprising the step of flowing out the organic waste treated in a medium temperature reactor after step (2). The method of claim 1, wherein step (1) (a1) a step of introducing organic waste into a high temperature reactor containing hydrolyzed microorganisms, acid-fermenting microorganisms and methane-producing microorganisms as anaerobic microorganisms, (a2) process of generating methane gas from organic wastes by hydrolysis, acid fermentation and methanation of the introduced organic wastes with anaerobic microorganisms, (a3) after the step (a2) to precipitate organic waste and anaerobic microorganisms to separate the solid and liquid by gravity, (a4) A method for treating organic waste, characterized by including the step of flowing out the supernatant generated after the step (a3) from the high temperature reaction tank and introduced into the middle temperature reaction tank. The method of claim 1, wherein step (2) (b1) The organic wastes of the supernatant from the high temperature reactor are anaerobic microorganisms, which are hydrolyzed, acid-fermented and methanated with anaerobic microorganisms in a medium temperature reactor containing hydrolyzed microorganisms, acid-fermenting microorganisms and methane-producing microorganisms. Methane gas generating process, (b2) separating the solid / liquid by gravity by precipitating organic waste and anaerobic microorganisms after the step (b1); (b3) after the step (b2) the step of flowing out the supernatant treated with organic waste from the medium temperature reaction tank, (b4) a method for treating organic waste, comprising the step of introducing the supernatant generated from the high temperature reactor after the step (b3) into the medium temperature reactor. delete delete The method of claim 1, wherein the organic waste is any one selected from food waste, sewage and wastewater sludge, agricultural waste, and livestock waste, or a mixture thereof.

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