KR100354968B1 - Annexation disposal method of food waste and sewage - Google Patents

Abstract

In the present invention, by combining anaerobic digestion of food waste and sewage sludge, food waste and sewage sludge are made to minimize the mechanical problems during the microbial reaction process transfer and to homogenize organic materials to maintain the reaction conditions consistently. It relates to a merge processing method of.

The treatment method of the present invention collects and transports the food wastes, each of which is fed in an appropriate amount, and receives the water and rotates the hopper-type sorting grinder 10, and among the impurities fed into the sorting grinder 10, to pick up a contaminant such as vinyl. Vinyl sorter 20 for separating as an outer device, an automatic sorter 30 including a drum screen to separate the light specific gravity of a relatively small size connected to the sorting mill 10 and the sorting mill 10 ) Is connected to the food waste processing system including a storage box (40) of the iron to separate the contaminants having a relatively large specific gravity, such as iron, and a cyclone (50) connected to the sorting mill (10) to separate the organic matter Food waste mixed with various substances can be mixed with vinyl-type contaminants, small-sized light specific materials, and large specific contaminants such as metals, and organic materials. Separation treatment, while maintaining the strong alkali state while supplying a certain amount of sodium hydroxide from the sodium hydroxide tank in the hydrolysis tank 70 in the hydrolysis tank 70 to promote hydrolysis, the hydrolyzed organic in the acid fermentation tank 71 It is characterized in that the microorganisms are converted to organic acids, and the sewage sludge is mixed in the anaerobic digestion tank 72 to convert most of the sewage sludge and the food waste converted into the organic acids into methane gas and carbon dioxide by methane fermentation bacteria. It is done.

Description

Combined disposal method of food waste and sewage sludge {Annexation disposal method of food waste and sewage}

In the present invention, by combining anaerobic digestion of food waste and sewage sludge, food waste and sewage sludge are made to minimize the mechanical problems during the microbial reaction process transfer and to homogenize organic materials to maintain the reaction conditions consistently. It relates to a merge processing method of.

Since most food wastes are organic materials, they have problems in stabilizing leachate and ground at disposal. Therefore, the existing methods for treating food waste can be divided into composting, feed, drying, and dehydration. However, the composting method is not only rejected by consumers but also composted when used for a long time. The effects of salinity on the soil have not been proven.

In addition, the method of feed should be thoroughly separated in advance, but recently, it has been found that feed made of food waste cannot be a good food for livestock.

In addition, drying or dehydration may be a method of reducing weight, but it is not a final treatment of degradable organic matter.

On the other hand, the general characteristics of the sewage sludge showed that the organic matter content was not high even after anaerobic digestion due to the low content of organic matter. Therefore, there is an urgent need for a method that can be economically treated as well as not rejecting existing organic waste treatment methods such as food waste and sewage sludge.

The present invention has been made to solve the conventional problems as described above, the object of the present invention by minimizing the anaerobic digestion of food waste and sewage sludge to minimize mechanical problems during the microbial reaction process transfer and homogenized organic material The present invention provides a method of merging food waste and sewage sludge that allows efficient treatment such as maintaining a constant reaction condition.

Combined treatment method of food waste and sewage sludge of the present invention for achieving the above object is a hopper-type sorting crusher for mixing and transporting the food waste collected and transported by a suitable amount, and the mixture is put into the sorting crusher A vinyl collector which separates the contaminants, such as vinyl, among the contaminants as an outer device, an automatic sorter including a drum screen connected to the sorting grinder to separate and process a relatively small amount of light specific gravity, and is connected to the sorting grinder By using a food waste processing system including a metal storage box for separating a contaminant having a relatively high specific gravity such as iron, and a cyclone connected to the sorting pulverizer to separate organic matter, food waste mixed with various substances is a vinyl type. Clutter, light heavy matter, small sized A large specific contaminant, such as a complex, and the organic material is separated, and the separated organic material in a hydrolysis tank while supplying a certain amount of sodium hydroxide from the sodium hydroxide tank while maintaining a strong alkaline state, and in the acid fermentation tank The microorganism converts the hydrolyzed organic matter into organic acid, and incorporates sewage sludge in an anaerobic digestion tank to convert most of the sewage sludge and food waste converted into organic acid into methane gas and carbon dioxide by methane fermentation bacteria. It features.

1 is a schematic diagram illustrating a pretreatment process of food waste;

2 is a block diagram of an apparatus for performing a pretreatment process of food waste,

Figure 3 is a perspective view of the main part of the sorting crusher constituting the food waste pretreatment device,

4 is a cross-sectional configuration diagram of a cyclone constituting a food waste pretreatment device;

5 is an overall processing system diagram in which the configuration of the present invention is linked.

<Explanation of symbols for the main parts of the drawings>

10: sorting mill 11: iron outlet

12: food outlet 13: vortex generation

14: Sewage outlet 15: Receptacle

16: cutter 17: discharge hole

18: cutter rotating body 19: water supply pipe

20: Vinyl Collector 21: Dispenser

22: crusher 30: automatic separator

31: cutter rotating body 32: drum screen

32a: hole 33: screw

34,41: rinse water supply pipe 40: metal storage box

50: cyclone 51: inlet

52: outlet 53: body

54,56: Gate 55: Receptacle

60: concentration tank 70: hydrolysis tank

71: acid fermentation tank 72: anaerobic digestion tank

73: NaOH tank

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

1 is a schematic diagram illustrating a pretreatment process of food waste, FIG. 2 is a configuration diagram of a device for performing a pretreatment process of food waste, FIG. 3 is a perspective view of a main part of a sorting grinder constituting a pretreatment apparatus of food waste, and FIG. 5 is a cross-sectional configuration diagram of a cyclone constituting a food waste pretreatment apparatus, and FIG. 5 is an overall processing system diagram in which the configuration of the present invention is linked.

As shown, the combined food waste and sewage sludge treatment method of the present invention is roughly divided into a step of treating food waste and a step of treating the separated organic material with the sewage sludge.

The processing system for food waste is once again described on the basis of the similarity to the system proposed in the patent application No. 98-11183 filed by the applicant.

1 to 4 are diagrams for explaining this, the food waste treatment system of the present invention is a hopper-type sorting grinder (10) in which food waste collected and transported as shown in FIG. ), And a vinyl collector 20 for separating the contaminants, such as vinyl, from the contaminants introduced into the sorting mill as an outer device, and connected to the sorting mill 10 so as to separate and process light specific gravity of a relatively small size. Is connected to the automatic sorting machine 30 including a drum screen, the storage box 40 of the iron is connected to the sorting crusher 10 to separate the contaminants having a relatively large specific gravity, such as iron, and the sorting crusher 10 It is roughly divided into the cyclone 50 which isolate | separates organic substance.

The sorting crusher 10 has a metal outlet 11 and the food outlet 12 is formed on one side of the lower side and the vortex generating piece 13 and the light gravity discharge outlet 14 communicated with the inside on one side of the outer wall is installed. The cylinder 15 and a plurality of cutters 16 are installed in the circumferential direction and a plurality of discharge holes 17 are formed so as to penetrate through the inner bottom surface from the lower portion of the receiving cylinder 15 and by the motor M. And a water supply pipe 19 for supplying water to the rotating cutter rotor 18 and the accommodation cylinder 15.

The vinyl collector 20 is installed on the outside of the sorting mill 10 and includes a shredder 22 for shredding the extractor 21 and the drawn vinyl.

The automatic separator 30 is connected to the outlet 14 of the light specific gravity installed in the sorting mill 10, and another cutter rotating body 31 having the same configuration as that of the cutter rotating body 18 installed in the sorting mill is disposed therein. In addition, the electric valve 35a is installed so that water can be supplied properly.

In addition, the automatic sorter 30 is connected through a connecting pipe 36 having an electric valve 36a, and a plurality of holes 32a are formed to rotate the drum screen 32, the screw 33 and the washing water supply pipe. 34, a recovery pipe 37 having an electric valve 37a is provided at the rear end of the automatic separator 30 to collect a small amount of food waste mixed together.

The metal storage box 40 is connected to the metal outlet 11 formed at the lower end of the sorting crusher 10, the storage box 40 is provided with electric valves (42a, 42b) up and down, electric valve A washing water supply pipe 41 having a 41a is connected.

The cyclone 50 is connected to the pulverized food waste outlet 12 formed at the bottom of the sorting crusher 10 as shown in Figure 4, the inlet 51 and the outlet 52 is formed at the top and the bottom A body 53 provided with a gate 56 actuated by the electric valve 56a, a gate 54 connected to the lower side of the body and operated by an electric valve 54a at the lower end, and an electric valve 57a on the upper wall. The water supply pipe 57 is operated to include a foreign matter container 55 is installed, and the pump 58 is installed in the connection pipe connecting the outlet 12 and the cyclone (50).

At this time, the direction of the inlet 51 is installed to face the inner peripheral wall of the body out of the center of the body (53).

On the other hand, the cyclone 50 may be connected to the acid fermentation process, which is a subsequent step without connecting the concentration tank 60 or through the concentration tank 60 so as to have a suitable moisture content of the separated and crushed food waste.

The food waste loaded into the vehicle as shown in FIG. 1 as described above is introduced into the receiving container 15 of the sorting crusher 10 through a storage hopper-automatic feeder-transport conveyor and through a water supply pipe 19. When water is supplied and the motor M is operated, the food waste in the container 15 is rotated by the cutter rotor 18 so that the vortex generating piece 13 formed on the inner wall of the container 15 and the cutter ash. By the action of the cutters 16 installed on the upper surface of the whole 18 is caused to rotate and rotate.

That is, relatively light contaminants such as Schiropol and vinyl and relatively heavy contaminants such as food, metal, and sand are separated through the sorting grinder 10, and in particular, the food waste is rotated in the container 15 of the grinder 10. The sunken food is crushed by the cutter 16 of the cutter rotating body 18 and passes through a plurality of discharge holes 17 formed in the bottom surface of the cutter, and the food passed through the food outlet 12 again. Is accommodated in the cyclone 50.

That is, the food coming into the state hitting the inner wall of the body 53 through the inlet 51 is rotated by causing a flow in the body 53, at this time, the heavy object contained in the food rotates on the inner wall of the body Down and piled up in the receiving container 55, the relatively light water and food floats while rotating and exit through the outlet (52).

Therefore, the food exiting through the outlet 52 is made of an organic material, which is a pure food that is hardly mixed with foreign matter.

On the other hand, the pure food exited through the outlet 52 may be accommodated in the concentration tank 60, which is the next process, and concentrated, otherwise it is subjected to an acid fermentation process which is the core component of the present invention.

As shown in FIG. 5, the acid fermentation process includes a hydrolysis tank 70 connected to a cyclone 50 or a concentration tank 60, an acid fermentation tank 71, an anaerobic digestion tank 72, and the hydrolysis tank 70. ) And a sodium hydroxide tank (73) connected with the acid fermentation tank (71), and the anaerobic digestion tank (72) is capable of mixing sewage sludge.

In this configuration, the foreign matter separation, crushing, and pulverized food waste are recycled together with sewage sludge while biologically decomposing the acid fermentation process.

Anaerobic reaction is a process in which biologically degradable organic matter is decomposed into carbon dioxide (CO ₂ ) and methane gas (CH ₄ ) in the absence of oxygen, but in reality, the reaction route and microorganism are not precisely identified according to the type of organic matter. Reaction.

In general, anaerobic decomposition reactions are classified into hydrolysis stage, acid generation stage, and methane generation stage, but the hydrolysis stage is included in the acid generation stage and divided into two processes, acid generation stage and methane production stage. In fact, a single-phase anaerobic tank which completes all of these anaerobic reactions in one reactor, and a two-phase anaerobic reactor, which generates methane after an acid generating reaction, are widely used.

The acid generation step may be represented by an organic material + H ₂ O → organic acid (Acetate, Propionate, Butyrate, etc), the methane production step is an organic acid (Acetate, Propionate, Butyrae, etc) + H ₂ → CO ₂ + CH ₄ In the above two-step reaction, C _n HaOb + (n-a / 4-b / 2) H ₂ O → (n / 2-a / 8 + b / 4) CO _{2 + (} n / 2 + a / 8-b / 4) CH ₄ can be represented by one equation.

When anaerobic digestion of the above two-stage reaction is carried out in one reactor, the pH is decreased due to the production of volatile organic acids (Volatile Fatty Acids), which is an intermediate product during acid production, which inhibits methane production.

In general, the suitable pH for acid-producing bacteria is known to be 5.0-6.5, and methane-producing bacteria is 6.8-7.2. The alkalinity for properly maintaining the activity of the microorganism is preferably 2,000 mg / L (as CaCO ₃ ) or more.

However, the hydrolysis process in the acid production stage is a process in which the macromolecule is hydrolyzed into low molecular substances by extracellular enzymes secreted by various microorganisms, and is known as the rate-limiting step of the entire anaerobic reaction.

Therefore, in the present invention, the anaerobic decomposition process may be treated more stably in a faster time by reacting the acid production step by separating the hydrolysis process and the acid production process.

That is, the present invention, as shown in FIG. 5, through the hydrolysis and sporadic effect wells and methane production reaction in the anaerobic digestion tank with the sewage sludge.

The hydrolysis tank 70 is introduced into the organic matter of the sorted, crushed, crushed food waste at this time is supplied with a certain amount of sodium hydroxide from the sodium hydroxide tank 73 to promote the hydrolysis process while maintaining a strong alkali state .

At this time, the pH in the reaction tank is maintained at 11 or more, the temperature is maintained at 35 ℃ or more and the required reaction time is maintained about 0.5 ~ 2 days.

In the acid fermentation tank 71, microorganisms are converted to organic acids, which have already been hydrolyzed. In this process, since the pH in the reaction vessel drops sharply, the NaOH already supplied to the hydrolysis tank 70 prevents the pH drop of the acid fermentation tank 71 and also the pH-Meter and NaOH supply pumps installed in the acid fermentation tank 71 ( Not shown) is preferably configured to automatically supply NaOH when the pH is lowered to 5 or less.

The reaction conditions of the acid fermentation tank 71 can be maintained at a temperature in the middle temperature range of 35 ~ 37 ℃ or 55 ~ 60 ℃ high temperature region, the reaction time is maintained for about 0.5 to 3 days.

In the anaerobic digestion tank 72, most of the sewage sludge and food waste already converted into organic acids are converted into methane gas and carbon dioxide by methane fermentation bacteria.

The reaction conditions of the anaerobic digestion tank 72 is maintained at a temperature of 35 ~ 37 ℃, required reaction days 10 to 30 days, pH is 7.0 to 7.5.

As described above, in the combined treatment method of food waste and sewage sludge of the present invention, the food waste mixed with various substances is separated and processed by each type by one system, and the separated organic material is separated from the hydrolysis tank. By supplying a certain amount of sodium hydroxide, it maintains a strong alkali state to promote hydrolysis, and the microorganisms to convert the organic material already hydrolyzed in the acid fermentation tank to organic acid, and in the anaerobic digestion tank to mix the sewage sludge with the sewage sludge By converting most of the food waste already converted into organic acid into methane gas and carbon dioxide by methane fermentation bacteria, it effectively sorts and separates the food waste mixed with a lot of foreign substances to minimize mechanical problems during the microbial reaction process transfer, Reaction conditions by homogenizing organic materials The effect is thereby kept constant.

In addition, it is possible to react the acid fermentation process in a short time and stably by the living organisms by going through the hydrolysis process during food waste treatment. Due to the lowering of the pH, it may cause inhibition of the activity of methane-producing bacteria, but this phenomenon can be prevented, and the cellulose component may form a scum layer due to the difference in acid fermentation rate when food waste is directly injected into the digester. By performing the hydrolysis by, it is possible to prevent such a problem to exhibit the effect.

Although the invention has been described in detail only with respect to the described embodiments, it will be apparent to those skilled in the art that modifications and variations can be made within the spirit and scope of the invention, and such variations or modifications will belong to the appended claims. .

Claims (3)

Separating hopper-type sorting pulverizer 10, which collects and transports the food wastes into a proper amount and feeds the water, and separates the debris, such as vinyl, from the crushed matters fed into the sorting pulverizer 10 as an external device. It is connected to the vinyl collector 20, the sorting mill 10, the automatic sorter 30 including a drum screen so as to separate the light specific gravity of a relatively small size, and is connected to the sorting mill 10, By a food waste treatment system including a metal storage box 40 for separating contaminants having a relatively large specific gravity, and a cyclone 50 connected to the sorting crusher 10 for separating organic matter, The mixed food waste is separated into vinyl type impurities, small sized light specific gravity, large specific gravity such as metal, and organic matter. The separated organic material is hydrolyzed while supplying a certain amount of sodium hydroxide from the sodium hydroxide tank 73 in the hydrolysis tank 70 to promote hydrolysis while maintaining a strong alkali state, In the acid fermentation tank 71 to convert the hydrolyzed organic material into organic acid, Combined sewage sludge in the anaerobic digestion tank 72 to convert the waste water and most of the food waste converted to the organic acid to methane gas and carbon dioxide by methane fermentation bacteria, characterized in that the combined treatment method . delete The food waste of claim 1, wherein the acid fermentation tank 71 is connected with a pH-Meter and a NaOH supply pump to automatically supply sodium hydroxide from the sodium hydroxide tank 73 when the pH is lowered to 5 or less. Method of merging wastewater and sewage sludge.