KR20210120958A - Treatment method of food wastewater - Google Patents

Abstract

The present invention relates to a method for treating food wastewater. The method for treating food wastewater according to the present invention includes: a screening step of filtering raw water from food wastewater with a filter in a filtration tank; a water collecting step of putting the food wastewater that has passed through the screening step into a water collecting tank; a first reaction step of treating a beneficial microorganism (BM) and performing aeration; and a second reaction step of putting the food wastewater that has undergone the first reaction step into a bioreactor and performing a second reaction.

Description

TREATMENT METHOD OF FOOD WASTEWATER

The present invention relates to a method for treating food wastewater. More specifically, it is to provide a step of pre-treating food wastewater to the extent that it can be treated by introducing it into a general wastewater treatment facility through the process of a primary reaction using complex microorganisms and a secondary reaction using an active bioreactor.

Food waste discharged from homes, restaurants, hotels, and food manufacturing processes, etc. is recycled by being manufactured into feed, compost, etc. through a crushing process and a dehydration process. In the process of recycling food waste as described above, food wastewater is generated.

In particular, in modern society, as factory-type food companies appear, industrial facilities that mass-produce various foods have increased, and accordingly, the amount of food waste and wastewater generated in the food production process has increased. Accordingly, various methods for disposing of food waste are being sought.

As a conventional food waste treatment method, incineration or landfilling was used, but in the case of incineration, the problem of air pollution was serious, and in the case of landfill, it was difficult to secure a landfill, and the problem of groundwater or soil contamination by leachate after landfilling. there was.

Accordingly, since food waste has a high content of organic matter and does not contain natural toxins or artificial toxic substances such as heavy metals or pesticides, many technologies that can be recycled as agricultural fertilizers or livestock feed have been developed. However, in the process of treating the food waste, the dehydration process must be performed, and the food wastewater (wastewater generated from the food waste) generated in the dehydration process has a high salinity, so it is cumbersome to be discharged after separate salt treatment There is this. In addition, since the residue remaining after the dehydration process contains a large amount of salt, when it is used as agricultural fertilizer for many years, the salt contained in the food waste accumulates in the soil, causing a serious problem in plant cultivation and avoiding its use. It is becoming.

There is a typical fertilizer field that utilizes the above food waste, and various technologies for removing salt from the food waste have been proposed in the fertilizer field. However, in order to be recycled as fertilizer, etc., food wastewater from food waste must be removed and a certain processing process must be carried out.

In the case of food waste, the amount of food wastewater is considerable. In particular, in the case of plant foods such as Chinese cabbage, the amount of food wastewater generated is significant because the moisture content is about 90% or more. Therefore, it is necessary to increase the efficiency of the method of removing the odor of the generated food wastewater and treating it to the extent that it can be treated in a general wastewater treatment plant.

However, food wastewater contained in food waste contains a large amount of fiber contained in plants in addition to water, and thus has a problem in that it is very difficult to treat unlike general wastewater. Therefore, it is important to remove a large amount of fiber, to remove the odor of food wastewater, and to decompose the pollutant to the extent that it can be treated in a general wastewater treatment plant.

Korean Patent No. 10-0450718 (registration on Sept. 20, 2004; hereinafter referred to as 'Prior Document 1') discloses that salt contained in food waste is mixed with atomized steelmaking slag so that activated CaO in the steelmaking slag and A method for producing an organic fertilizer with reduced salinity in food waste by causing NaCl to undergo a substitution reaction has been disclosed. I had this annoying problem.

In addition, Korean Patent Registration No. 10-0884601 (registered on Feb. 12, 2009; hereinafter referred to as 'Prior Document 2') describes a method for treating organic waste such as food waste by using waste heat generated from an incinerator, etc. to preheat the organic waste. There is disclosed a method for treating organic waste, which includes a step of stabilizing by first heating and stirring by applying additional heat with a preheating device, then mixing the waste oyster shells with secondary heating and stirring to stabilize them. There was a problem that facilities such as an incineration plant that could be used were equipped.

In addition, in Korea Patent No. 10-1178450 (registration on August 24, 2012; hereinafter referred to as 'Prior Document 3'), organic waste such as food is mixed and stirred with quicklime and cocopit, a deodorizing and moisture control agent, There is a method of producing lime-treated fertilizer by inducing a chemical reaction, but this method of simply mixing and stirring coco peat and quicklime with food waste does not have high reaction efficiency, and requires the addition of relatively large amount of quicklime to remove moisture. There is a problem.

US 10-0450718 B1 US 10-0884601 B1

It is an object of the present invention to provide a food wastewater treatment method capable of effectively removing odors and pollutants to the extent that the fiber-containing food wastewater can be treated by putting it into a general wastewater treatment plant.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for rapidly and effectively removing odors from food wastewater, which is rapidly generated in the wastewater treatment step.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for treating food wastewater that can effectively purify the organic food wastewater of high concentration.

In order to achieve the above object, a method for treating food wastewater according to an embodiment of the present invention includes: a screen step of filtering raw water from food wastewater with a filter in a filtration tank; a water collecting step of putting the food wastewater that has passed through the screening step into a water collecting tank; a first reaction step by treating Beneficial Microorganisms (BM) in the water collecting tank and aeration; and a secondary reaction step of putting the food wastewater that has undergone the first reaction step into a bioreactor and performing a second reaction.

In the food wastewater treatment method, the bioreactor may be a tower type, and a membrane module may be installed in the bioreactor.

In the food wastewater treatment method, the complex microorganisms include Bacillus subtilis, Corynebacterium and Saccharomyces, and the complex microorganisms are adsorbed to the porous inorganic material. there may be

In the food wastewater treatment method, the porous inorganic powder may be fine powder silica having an oil absorption amount of 200 to 300 ml and a specific surface area of 200 to 400 (m ^{2 /g).}

In the food wastewater treatment method, the porous inorganic powder may be one that is further adsorbed with an extract of Osmunda japonica and Juniperus rigida S. et Z.

The food wastewater treatment method includes a coagulation step of mixing calcium carbonate and colloidal silica with the food wastewater that has undergone the first reaction step after the first reaction step; and transferring the food wastewater that has undergone the coagulation step to the filtration tank, and may further include a ash screen step of filtering again through a filter.

Microorganisms for food wastewater treatment according to another embodiment of the present invention include complex microorganisms including Bacillus subtilis, Corynebacterium and Saccharomyces; And gobi (Osmunda japonica) extract and juniper (Juniperus rigida S. et Z.) extract may be one containing the adsorbed porous mineral.

In the microorganism for food wastewater treatment, the porous inorganic powder may be fine powder silica having an oil absorption amount of 200 to 300 ml and a specific surface area of 200 to 400 (m ^{2 /g).}

Hereinafter, the present invention will be described in more detail.

A method for treating food wastewater according to an embodiment of the present invention includes: a screen step (S1) of filtering raw water from food wastewater with a filter in a filtration tank; a water collecting step (S2) of putting the food wastewater that has passed through the screen step into a water collecting tank; The first reaction step (S3) by treating and aeration with Beneficial Microorganism (BM) in the water collecting tank; and a secondary reaction step (S4) of putting the food wastewater that has undergone the first reaction step into a bioreactor and performing a second reaction.

Food wastewater as used in the present invention refers to food-based wastes generated in the food manufacturing process or food disposal process, and is defined as wastewater containing sludge because of its very high moisture content.

Specifically, when describing the general characteristics of the food wastewater, the food wastewater contains a large amount of microfibers derived from plants, and is a high-concentration organic wastewater with a BOD of 15,000 to 20,000PPM. It is common to generate a large amount of odor. Therefore, it is impossible to directly treat the food wastewater through a general wastewater treatment device or facility, and a certain pretreatment step is essential.

In the case of general food wastewater, the moisture content is more than 80%, and in general, it is often more than 90%. Therefore, it is necessary to proceed with the screen step (S1) of obtaining only the wastewater by filtering the raw food wastewater using a filter in the filtration tank. The filter may vary depending on the type of food wastewater to be treated, but may preferably be a 20 to 200 mesh filter.

When the filter is used in the above range, it is possible to remove relatively large fibers that are difficult to remove in the food wastewater treatment step to be described later. Therefore, when the filter exceeds 200 mesh, there is a problem that fibers that are difficult to decompose in the food wastewater treatment step remain in the wastewater, and the decay continues, so that it cannot be treated in a general wastewater treatment apparatus. On the other hand, in the case of less than 20 mesh, the filtration efficiency is lowered by filtering down to fibers that can be decomposed in the wastewater treatment device. there is

The first reaction step (S3) is a kind of activated sludge process by treating Beneficial Microorganism (BM) in the water collecting tank and aeration. (mean cell residence time, θx), or sludge retention time (SRT). This condition is equal to the reciprocal of the specific growth rate (μ). If this is expressed as an equation, it is as follows [Equation 1].

[Equation 1]

Here, x1, x2 and x3 are the cell concentrations in the water collecting tank, effluent water and waste sludge, respectively, F2 and F3 are the flow rates of the waste water and waste sludge, respectively, and V is the volume of the water collecting tank.

The hydraulic retention time (HRT, θ) is the average time the influent stayed in the process and is the reciprocal of the dilution rate D. where F1 is the flow rate of the influent. If this is expressed as an equation, it is as follows [Equation 2].

[Equation 2]

The growth rate, residence time, and dilution rate of microorganisms can be selected within an appropriate range in consideration of the food wastewater treated based on [Equation 1], the amount of treatment, the flow rate, and the type of complex microorganisms.

The second reaction step (S4) refers to a step of introducing the food wastewater that has undergone the first reaction step into a bioreactor and performing a second reaction.

In the second reaction step, the food wastewater can be purified to the extent that it can be treated with a general wastewater treatment device by dividing the unreacted material not treated in the first reaction step through an additional microbial reaction after the first reaction step.

Preferably, the bioreactor is Lactobacillus delbrueckii (Lactobacillus delbrueckii), Lactobacillus rhamnosus (Lactobacillus rhamnosus), and Streptomyces griseus (Streptomyces griseus) may be one using a mixed microorganism.

More preferably, the microorganisms used in the bioreactor are Lactobacillus delbrueckii, Lactobacillus rhamnosus, Streptomyces griseus, Aspergillus flavus duck material. flavus oryzae) and Penicillium expansum may be used as a mixed microorganism.

In the food wastewater treatment method, the bioreactor may be a tower type, and a membrane module may be installed in the bioreactor.

Membrane module as used in the present invention is defined as saying that two or more biofilters in which microorganisms are cultured are overlapped.

The tower type refers to a cylindrical shape, and the tower type bioreactor may have a membrane module installed therein.

In the food wastewater treatment method, the complex microorganisms include Bacillus subtilis, Corynebacterium and Saccharomyces, and the complex microorganisms are adsorbed to the porous inorganic material. there may be

In the case of the complex microorganisms, it is possible to effectively decompose fibers and other contaminants contained in food wastewater, and to react quickly to prevent spoilage, thereby removing odors.

In the food wastewater treatment method, the porous inorganic powder may be fine powder silica having an oil absorption amount of 200 to 300 ml and a specific surface area of 200 to 400 (m ^{2 /g).}

When the porous inorganic powder is used as a carrier, it can be effectively dispersed in food wastewater, and has a high reaction efficiency compared to the same mass due to a relatively large specific surface area, so that it is effective in treating food wastewater. In addition, in the case of using the fine powder silica according to the above range, stable growth of microorganisms is possible, and it is easy to remove the carrier after wastewater treatment.

In the food wastewater treatment method, the porous inorganic powder may be one that is further adsorbed with an extract of Osmunda japonica and Juniperus rigida S. et Z.

When the plant extract is included, the activity against the microorganism may be enhanced, thereby increasing food wastewater efficiency. In particular, as the activity against microorganisms increases, odors generated from food wastewater are quickly controlled.

Preferably, the porous inorganic powder may include a gobi extract, and 10 to 30 parts by weight of a juniper extract and 1 to 10 parts by weight of a ramie extract based on 100 parts by weight of the gobi extract.

In the case of the above range, since the activity against the complex microorganisms is greatly increased, the treatment activity for food wastewater is significantly increased and the odor removal efficiency is increased.

The food wastewater treatment method includes a coagulation step (S3.1) of mixing calcium carbonate and colloidal silica with the food wastewater that has undergone the first reaction step after the first reaction step; and a ash screen step (S3.2) of transferring the food wastewater that has undergone the coagulation step to the filtration tank and filtering it again through a filter.

Microorganisms for food wastewater treatment according to another embodiment of the present invention include complex microorganisms including Bacillus subtilis, Corynebacterium and Saccharomyces; And gobi (Osmunda japonica) extract and juniper (Juniperus rigida S. et Z.) extract may be one containing the adsorbed porous mineral.

In the microorganism for food wastewater treatment, the porous inorganic powder may be fine powder silica having an oil absorption amount of 200 to 300 ml and a specific surface area of 200 to 400 (m ^{2 /g).}

Preferably, the porous inorganic powder may include a gobi extract, and 10 to 30 parts by weight of a juniper extract and 1 to 10 parts by weight of a ramie extract based on 100 parts by weight of the gobi extract.

The present invention provides a food wastewater treatment method that can effectively remove odors and pollutants to the extent that the fiber-containing food wastewater can be treated by putting it into a general wastewater treatment plant.

In the case of the food wastewater treatment method according to the present invention, in the case of food wastewater, it is possible to more quickly and effectively remove odors rapidly generated in the wastewater treatment step.

The food wastewater treatment method according to the present invention can have an effective purification effect on organic food wastewater of high concentration.

1 is a flowchart of a food wastewater treatment method according to an embodiment of the present invention.
2 is a flowchart of a food wastewater treatment method according to an embodiment of the present invention.
3 is a photograph comparing the food wastewater of the present invention and the treated water treated according to the food wastewater treatment method according to an embodiment.

Hereinafter, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein.

[Experimental Example: 1st reaction stage experiment]

After obtaining the wastewater (baechu green juice) generated in the process of producing cabbage kimchi in the Chinese cabbage kimchi factory, it was filtered through an 80 mesh filter, and the first reaction step was tested for the filtered cabbage green juice.

For use in the first reaction step, the fine powder silica having an oil absorption amount of 200 to 300 ml and a specific surface area of 200 to 400 (m ² /g) is impregnated with a microbial culture solution as shown in [Table 1] below, or additionally as shown in [Table 1]. A microbial agent for food wastewater treatment was prepared with the composition shown in [Table 3] below by impregnating the plant mixture as shown in Table 2].

On the other hand, the plant extract was prepared as a hot water extract.

A1 A2 A3 Bacillus subtilis O X O Corynebacterium O O O Saccharomyces X O O

B1 B2 B3 B4 B5 B6 B7 B8 B9 gobi extract 100 100 100 100 100 100 100 100 100 juniper extract 5 10 20 30 40 20 20 20 20 ramie grass extract - - - - - 0.5 One 10 15

(Unit: parts by weight)

M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M11 M12 A1 O - - - - - - - - - - - A2 - O - - - - - - - - - - A3 - - O O O O O O O O O O B1 - - - O - - - - - - - - B2 - - - - O - - - - - - - B3 - - - - - O - - - - - - B4 - - - - - - O - - - - - B5 - - - - - - - O - - - - B6 - - - - - - - - O - - - B7 - - - - - - - - - O B8 - - - - - - - - - - O B9 - - - - - - - - - - - O

Using the microorganism impregnated with the composition as shown in [Table 3], the microorganism was dispersed while reproducing the aeration state in the filtered Chinese cabbage green juice to evaluate the BOD value, the degree of odor and the microfiber decomposition ability.

The BOD of the obtained Chinese cabbage green juice stock solution was 15,000 mg/l, and in order to compare the experimental results, after the reaction treatment, BOD of 7,000 mg/l or more was D, BOD 4,000 to 7,000 mg/l C, BOD 2,000 to 4,000 mg/l B, BOD 2,000 mg/l or less was evaluated as A. On the other hand, the degree of odor and the microfiber were evaluated on an index of 1 to 10 through sensory evaluation and related evaluation. The lower the index, the better the effect.

The results are shown in [Table 4] below.

M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M11 M12 BOD D D C C C B B C B A A B stink 7 8 7 7 8 6 6 7 7 5 4 7 microfiber 8 8 6 6 7 5 6 7 7 4 4 6

Referring to [Table 4], when Bacillus subtilis, Corynebacterium, and Saccharomyces are used as complex microorganisms, the reaction efficiency for food wastewater is excellent. can be known

In addition, it can be seen that when a plant extract is contained, the activity of the microorganism is enhanced. In particular, it can be seen that according to the composition of M10 and M11, the activity against microorganisms is greatly increased, so that the BOD value is excellent, and the effect of reducing odor and removing microfibers is excellent.

[Experimental Example: Secondary Reaction Step Experiment]

A membrane module is manufactured using a biofilter in which complex microorganisms are cultured as shown in Table 5 below, and M10 is aerated into the primary reactant of Chinese cabbage green juice wastewater treated as the primary reaction step in the bioreactor in which the membrane module is installed. For this, a second reaction step experiment was carried out.

In the experimental step below, the BOD is 800 mg/l or less, the odor is reduced by 80% or more, and the degree to which it can be treated with general wastewater is denoted as P, otherwise, the result is shown in [Table 6] below. .

SF1 SF2 SF3 Lactobacillus delbrueckii O O O Lactobacillus rhamnosus O O O Streptomyces griseus X O O Aspergillus flavus oryzae X X O Penicillium expansum X X O

SF1 SF2 SF3 BOD F P P stink F F P

Referring to [Table 6], the complex microorganisms of Lactobacillus delbrueckii, Lactobacillus rhamnosus and Streptomyces griseus by the secondary reaction by the biofilter It can be seen that the BOD is further reduced when using In addition, Lactobacillus delbrueckii, Lactobacillus rhamnosus, Streptomyces griseus, Aspergillus flavus oryzae and Penicillium expanse expansum), the BOD is lowered and the odor disappears by more than 80%, so it can be seen that it becomes a level that can be treated by transferring it to a general wastewater treatment facility.

Although the preferred embodiment of the present invention has been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims are also provided. is within the scope of the

Claims (8)

A screen step of filtering the raw water of the food wastewater with a filter in the filtration tank;
a water collecting step of putting the food wastewater that has passed through the screening step into a water collecting tank;
a first reaction step by treating Beneficial Microorganisms (BM) in the water collecting tank and aeration; and
Including a secondary reaction step of putting the food wastewater that has undergone the first reaction step into a bioreactor and performing a second reaction
Methods of treatment of food wastewater. The method of claim 1,
The bioreactor is a tower type, and a membrane module is installed in the bioreactor
Methods of treatment of food wastewater. The method of claim 1,
The complex microorganisms include Bacillus subtilis, Corynebacterium and Saccharomyces,
The complex microorganism is adsorbed to the porous inorganic material
Methods of treatment of food wastewater. 4. The method of claim 3,
The porous inorganic material is fine powder silica having an oil absorption amount of 200 to 300 ml and a specific surface area of 200 to 400 (m ^{2 /g)}
Methods of treatment of food wastewater. 5. The method of claim 4
The porous inorganic material is
Gobi (Osmunda japonica) extract and juniper (Juniperus rigida S. et Z.) extract is more adsorbed
Methods of treatment of food wastewater. 5. The method of claim 4,
aggregation step of mixing calcium carbonate and colloidal silica with food wastewater that has undergone the first reaction step after the first reaction step; and
Further comprising a ash screen step of transferring the food wastewater that has passed through the coagulation step to the filtration tank and filtering it again through a filter
Methods of treatment of food wastewater. Composite microorganisms including Bacillus subtilis, Corynebacterium and Saccharomyces; and
Gobi (Osmunda japonica) extract and juniper extract (Juniperus rigida S. et Z.) containing adsorbed porous minerals
Microorganisms for food wastewater treatment. 8. The method of claim 7,
The porous inorganic material is fine powder silica having an oil absorption amount of 200 to 300 ml and a specific surface area of 200 to 400 (m ^{2 /g)}
Microorganisms for food wastewater treatment.

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