KR20040078660A - On-Site Treatment Method of Ground Food Wastes - Google Patents

Abstract

PURPOSE: Provided is an on-site treatment method of ground garbage from group residential facilities and group kitchen facilities which is able to fundamentally solve the problem of garbage generated in large cities by allowing the garbage to be treated in a small space within the generation site thereof. CONSTITUTION: The method comprises steps of grinding garbage by a grinder installed at the lower end of a kitchen sink; separating kitchen sewage from the ground garbage by a solid/liquid separator placed downstream of the grinder, the solid/liquid separator having a structure where a garbage pipeline(5) and a sewage drainpipe(6) are connected to each by a selection valve(4), provided that when the grinder(2) is not operated, kitchen sewage is transferred to the sewage drainpipe, and when the grinder is operated, the ground garbage is transferred to a secondary treatment system together with a small amount of kitchen water through the garbage pipeline; and secondarily treating the ground garbage in the secondary treatment system.

Description

{On-Site Treatment Method of Ground Food Wastes}

It is true that food waste in our country is generated as much as 8 trillion won of resources is wasted annually. Therefore, it is also true that food waste in our country, unlike other countries, coexists with both resources and waste, making it difficult to dispose of food waste. For this reason, according to 2000 statistics from the Ministry of Environment, the use of feed and compost furnace out of the total 11,350 tons generated, 5600 tons, the recycling rate accounted for 49.3%.

According to the existing treatment method, high-quality food waste is used as livestock feed as it is. Otherwise, the specific method is divided into on-site treatment and post-treatment treatment. In the US, the disposer method, Japan drying method and microbial fermentation method are used. In Europe, most Korean households, which account for 64% of food waste generation, rely on separate collection and disposal.

Many years ago, food waste generated in restaurants was installed and operated by hot air drying and fermentation-reducing resources, but it is currently inoperable due to excessive power costs and lack of service to evaporate odors and moisture. The method of treatment after collection relies on feed and composting, but feed is a hygienic treatment problem and compost is a salinity problem.

Recently, methods of extinction through anaerobic digestion as well as feed and compost have been adopted. The problems of feed and composting are as described above, and the extinction method through anaerobic digestion is considered to be treated alone or in sewage sludge and mixed treatment in cities, and in small apartment complexes, it is being used as a septic tank. This situation is increasing. For example, a living sewage and kitchen waste combined treatment system (Korea Patent Registration No. 10-280934) and a system for treating food waste and household sewage together with manure (Korean Patent Publication No. 10-2000-032344) are known. In addition, a method of treating organic waste (food waste) by adding aerobic microorganism, water, air, and hydrogen peroxide is known (Korea Patent No. 10-266089). However, such a system is characterized in that the food waste is treated together with the sewage without being separated after being transported from the source, or in the case of Korea Patent Registration 10-266089 it does not specifically adopt a hygienic transport method.

Meanwhile, a method of installing a separate pipe and transferring the crushed food waste using a vacuum pump, and then drying and reducing the fermentation is known (Korean Patent 10-0192561), but a separate pipe and a vacuum pump must be installed. Therefore, there is a disadvantage in that a large amount of equipment is required, as well as water and food waste used for pipe washing, and then sewage must be secondarily treated in a septic tank.

The present invention relates to a method for treating food waste at a generation site, characterized in that the food waste is separated from kitchen water before and after transportation to minimize the volume of food waste, and then treated in a small treatment facility. From the place of occurrence, such as apartments, group residences such as townhouses, group cooking facilities such as restaurants, and household food waste, the kitchen is crushed with a grinder without touching the hands, The present invention relates to a method for transporting a solid-liquid separator installed nearby to separate the kitchen water and then treating the separated food waste in a secondary treatment device.

Fig. 1 shows a comparison between the conventional method for treating food waste and the method of the present invention.

Fig. 2 shows various methods of separating the sewage and solids from the crushed food waste immediately after the crushing of the food waste, and transporting it immediately to the treatment site.

Fig. 3 shows the sewage flow of group residential facilities.

Fig. 4 shows various ways of separating and treating food waste from sewage.

Fig. 5 shows a device that completely separates food waste and kitchen waste before grinding.

Fig. 6A shows a device for separating household wastewater (except toilet water) and pulverized food waste including a solid-liquid separator B of a cylindrical screen type.

Fig. 6B shows a device for separating household wastewater (except toilet water) and pulverized food waste including a solid-liquid separator B of a flat screen type.

Fig. 6C shows a device for separating living sewage (except toilet water) and ground food waste including a solid-liquid separator B of a sand packed tower method.

Fig. Figure 7 shows a biological treatment device for the anaerobic treatment of small amounts of crushed food waste by separating and removing sewage.

Reference numerals of the present invention are as follows: (1) sink; (2) a mill; (3) food waste and sewage piping; (4); Selection valve; (5) food waste piping; (6) sewage pipes; (7) secondary processing units; (8) sewer pipes; (9) building floors; (10) cylindrical screen device; (11) cylindrical screens; (12) food waste inlet valves; (13) motors; (14) sewage storage tanks; (15) sewage discharge valves; (16) flat screen device; (17) food waste storage tanks; (18) sand packed tower; (19) anaerobic reactor; (20) aerobic reactor; (21) slurry circulation pumps; (22) thermostats; (23) an air injection device; (24) gas exhaust pipe.

Best Mode for Carrying Out the Invention

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are only for illustrating the present invention more specifically, it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples in accordance with the gist of the present invention. .

Example 1 apartment food waste disposal method (if there is a food waste dedicated pipe, new apartments)

The number of residential households per building of tenement houses or apartments in Korea ranges from 10 households to 200 households. In this case, the amount of food waste generated is about 0.25 kg (wet weight) per person per day, and the water content is about 80%.

The average number of residents per household is about 3.5 and the water consumption per person is about 200 liters. In the 10th generation, about 8.75kg and 200th generation produce about 175kg of food waste per day. Water usage is about 7 m ³ for 10 households and about 140 m ³ for 200 households.

If the dedicated piping is installed, the FIG. The use of Method C of 2 may be considered, but the sink has two sewage outlets, which is inconvenient. Thus, FIG. As in Method A of 2, the food waste is preferably separated from the kitchen waste through the solid-liquid separator A in the kitchen sink having one outlet. The kitchen sewage is discharged to the sewer through the existing sewage integration pipe (FIG. 3), and the crushed food waste is added to the secondary treatment unit after adding a small amount of water to facilitate the transfer. If necessary, a small amount of sewage may be further separated through the solid-liquid separator B before entering the secondary treatment apparatus.

Fig. Established in the Department of Biochemical Engineering, KAIST As a result of one year of operation of the biological treatment device (volume 1m ³ , about 20 households of food waste processing capacity) of 7, the food waste was completely digested and free of solid residue, methane gas and COD about 50mg / L and turbidity about 13O NTU Only levels of transparent treated water were discharged.

Example 2 apartment food waste disposal method (if there is no dedicated food waste piping, for existing apartments)

In a 90-family apartment with about 3.5 people per household, about 315 people live. The food waste generated here is 78.75 kg (approximately 315 x 0.25 kg / person). This food waste has a water content of 80% and a dry weight of about 15.75 kg. Tap water used daily per person when calculated as approximately 200L of about 63m or ^3, the actual amount used is from about ³ 80m or so.

Tap water is divided into toilet water, kitchen water, bath water, laundry water and cleaning water. After use, the toilet water is sent to the septic tank separately at about 22.5M ³ / day, and the kitchen sewage is about 22.5M ³ / day. Washing sewage, cleaning sewage and bath sewage are discharged together with kitchen sewage. The discharge amount is about 50 ~ 60M ³ / day, and the ratio of food waste included in this is 1/630 ~ 1/760.

Sewage separated from food waste by using solid-liquid separator B is treated after discharging COD using a filter, etc., so that it is cleaner than before mixing food waste, and eventually merged with toilet treatment sewage through a joint septic tank and discharged to sewage treatment plant. do.

Currently, food wastes are stored in waste bins and collected two or three times a week in storage in apartment complexes and transported to common treatment facilities outside the apartment complex.

Example 3 Method for Separating Kitchen Waste and Kitchen Waste

Currently, Korea prohibits the discharge of sewage, including crushed food waste, into sewage pipes. In this case, it is preferable to install a dedicated pipe for transporting the crushed food waste separately from the kitchen sewage discharge pipe in the kitchen. If two outlets are installed on the kitchen sink and the crushed food waste and kitchen sewage are discharged separately, only the sewage is transferred to the sewer pipe, and the food waste is crushed by the crusher installed upstream of the dedicated outlet, and then the transfer is smoothly performed. In order to add some water to the secondary treatment unit.

Fig. As illustrated in Method A of 2, use only one outlet in the sink and install a grinder to it. Solid-liquid separator A attaches grinder, T-shaped pipe, 1 on-off switch, and two sewage pipes (food waste pipe, waste water pipe) to open the food waste pipe only before and after the grinder operates to transport food waste. . The amount of water needed to transport the crushed food waste is no problem if it is more than twice the minimum amount of food waste.

Example 4 Separation of Food Waste and Sewage Smashed in the Household Sewage Pipe

At present, all apartments in Korea are equipped with only one sewage pipe in the kitchen and are discharged to the basement by being discharged to the apartment collective sewage pipe together with kitchen sewage, laundry sewage, and bath sewage (FIG. 3). Toilet sewers are operated separately. As the separation method does not have a dedicated pipe in the existing apartment, one part of food waste is mixed with 500 to 800 parts of water. It is preferable to adopt Method B of 2.

Solid-liquid separator B used in this experiment is shown in FIG. A schematic is shown at 6A. The cylindrical screen 11 embedded in the solid-liquid separator B has an inner cylinder diameter of about 15 cm, an outer cylinder diameter of about 20 cm, and a mesh size of about 0.5 mm. The diameter and mesh size of the cylinder can be adjusted according to the purpose, the mesh size is preferably 0.02 ~ 2.0mm. Crushed food waste and sewage conveyed through the pipe (3) flows into the rotating cylindrical screen (11), the sewage passes through the rotating cylindrical screen and then transferred to the sewage storage tank (14) through the inner space of the cylindrical screen The food wastes fall outward and accumulate at the inlet of the secondary processing unit without passing through the rotating cylindrical screen.

The cylindrical screen was continuously operated at about 60 rpm. Unlike other types of high-speed separators, the separators were separated at low speeds, and continuous separation without clogging was possible. See Example 5 for the water quality of kitchen sewage passed through solid-liquid separator B.

Example 5 COD Removal Efficiency of Food Waste in Solid-Liquid Separator B

Kitchen sewage from one household's kitchen is about 250 liters per day. Kitchen sewage can be divided into particulate kitchen waste and soluble kitchen waste that pass through the 5mm plastic wire mesh of the sink. All food waste collected in the kitchen is particulate. Soluble COD and particulate COD before and after crushing kitchen sewage and food waste using food waste from KAIST restaurant are shown in Table 1 below.

In Table 1, the ratio of particulate COD and soluble COD of kitchen sewage is about 50:50, and food waste 5g / L becomes dry weight of 1g / L, and a COD increase of about 1000 mg / L can be expected. Soluble COD did not change much, and it was found that most of the food waste remains particulate even after grinding.

Table 2 shows the results of COD removal using a rotating cylindrical screen device and a sand packing tower using food waste and kitchen sewage mixture generated in KAIST restaurant. The rotating cylinder screen has an inner cylinder diameter of about 15 cm, an outer cylinder diameter of about 20 cm, a mesh size of about 0.5 mm, and the experiment was performed while rotating at 60 rpm. The sand packed tower had a size of 8 × 3 × 40 cm, and the packed sand had a particle size of 2 to 5 mm. The flow rate of the influent was experimented at 3L / min.

Food waste and kitchen sewage generated in the kitchen are mainly generated during preparation time before and after washing dishes based on the time of breakfast, lunch and dinner. In the case of ordinary households, there is no sewage and garbage generation between 8 hours and 6 am. Group dwellings are likely to have a fairly wide distribution of kitchen sewage and food waste generation times, as meal times in different households are different.

For reference, the COD of 20L kitchen sewage collected before and after cooking at a home in Daejeon is 1950mg / L. This is considering that the kitchen sewage amount is about 250L, and when combined with washing sewage and bath sewage, it falls below 1000 mg / L. If food waste is added to this, it becomes about 0.175kg (0.25kg × 0.2 × 3.5), which is divided into daily water consumption, about 250L of kitchen sewage, and about 500L of household sewage, respectively, about 700mg / L and about 350mg / L COD. Is added. Since the average COD of household wastewater discharged from home is about 250 ~ 1000mg / L, it can be seen that kitchen waste COD and food waste COD can vary from about 1: 1.

Therefore, it is reasonable that the COD removal rate is based on the total amount of the day, that is, the integral removal rate, rather than the instantaneous differential removal rate. Table 3 assumes a 60% particulate COD removal rate for a solid-liquid separator B with a cylindrical screen method and a 65% particulate COD removal rate with a sand packed tower, while 500: 500 and 250 for kitchen sewage COD and food waste COD, respectively: COD removal rates were predicted when entering 250, 250: 500, 500: 250, 500: 1000, 1000: 500, and 1000: 1000.

In Table 3, S represents soluble food waste, P represents particulate food waste, and T represents the sum of S and P. As shown in Table 3, it was found that the sewage separated through the solid-liquid separator B remained similar to the water quality before the input of food waste.

Example 6 Biological Treatment of Food Waste

Food wastes from the kitchen are fed into the anaerobic bioreactor via solid-liquid separator B (FIG. 1A, Method A of Fig. 2). It is preferable to separate wastewater and food waste before putting food waste into the biological treatment device. Three methods A, B and C of 2 can be applied. That is, in the kitchen, Method A and C, which separate food waste and kitchen sewage through a dedicated pipe at source, and Method B, which separate food waste from a lot of water, may be used. Method B can only be used in existing apartments without food waste plumbing. The sewage separated by applying Method B is discharged to sewage pipe through filtration and treatment to maintain kitchen sewage and lactic acid water before mixing food waste, and the separated food waste is shown in FIG. It is automatically fed into the biological treatment device of 7. The feeding process is characterized by no pump being used.

For the 100 household apartment the reaction vessel of about 5m ^3, for 200 households is used a reaction vessel of approximately 10m ^3. Methane gas is generated here are each 15, and the remaining amount is 80% of the thermal insulation in the winter to 30m ³ per day. Food waste treatment water is COD 50mg / L, clear water of less than 130NTU turbidity is discharged and can be used as heavy water after further purification. Food waste disposal is anaerobic, minimizing additional energy consumption and smelling environmentally friendly, with no odor at all.

Example 7 Treatment of Food Waste in Collective Cooking Facilities

Group meal facilities such as schools and military units are concentrated in one place of food waste generation. Food waste is often contained in a colander with a hole in the form of a sieve separated from the water. The trash is separated by hand, put into a grinder in the kitchen, and a little water is added to the anaerobic treatment facilities inside and outside the kitchen. When food waste is mixed with kitchen sewage, the chopsticks, vinyl, and yogurt bottles are separated through the automatic sorting machine, and then separated from the kitchen sewage through the solid-liquid separator A, and then the food waste is put into the grinder. The pulverized food waste is transferred to the treatment site through a transfer pipe and subjected to anaerobic treatment to obtain biogas of about 1 m ³ having a methane content of 55 to 60% per kg COD. In the case of a feeding staff of about 1000 people, a dry weight of 40 kg (200 kg x 0.2) can be obtained, and the amount of methane gas generated therein is 40 m ³ (content 55 to 60%). This calorie remains 80% even when the temperature of the methane reactor is maintained at 35 ° C.

Example 8 Volume of Anaerobic Reactor for Food Waste Treatment

In the present invention, it is considered that the area for the food waste treatment facility of a group cooking facility such as an apartment, a school, a military unit, and the like should be treated sanitarily in the field. Facility to be treated in the present invention is a facility of less than 1000 people to use food waste generation amount is about 200kg per day.

In the case of the 90-generation apartment, the daily generation amount is about 87.5 kg and assuming a 20% content of dry weight is 17.5 kg. In case of treatment at 36 ℃ by anaerobic method, the required throughput per unit reactor volume is 1.6 ~ 7.9 kg / M ³ · day (Refer to Ho-Nam Jang & Jin-Ho Seo, Biochemical Engineering, 432p, Academic Book; Workshop Resources, p21, 1999). When treated by aerobic methods, the treatment capacity is 3 kg / M ³ .day (Park et al., Bioresource Tech., 73, 21-27, 2000). In addition, energy consumption is high when operating at a high temperature of 55 ° C, but the treatment speed is about doubled compared to 35 ° C. (SeoTech 1998, p572).

If based on the data above, calculate the volume of the tank, look at the daily throughput Seoul 2-8kgVS / m ^3, so if Cheongdam-dong, Gangnam-gu, Seoul apartments is required, the volume of the reactor 2~9m ^3. In the case of KAIST restaurants, anaerobic reactors require a dry weight of 40 kg, with 5-20 M ³ of space around them.

Example 9 Comparison of Convenience and Energy Consumption of the Process

According to the present invention, there is a necessity that the kitchen waste does not touch the food waste by hand. In other words, the food waste is not stored and stored after generation, and is ground and transported three to four times a day immediately after generation. It is a way to fundamentally solve the food waste problem in Korea by completely extinguishing the food waste separated from the solid-liquid separator without processing residue.

The anaerobic treatment method adopted in the present invention produces energy called methane gas, whereas in the United States, the aerobic treatment by crushing and sending it to a sewage treatment plant consumes energy, and thus, the present invention is more energy-saving and economical. . For example, suppose that only 50% of the 4 million tons of food waste generated in Korea is treated in a sewage treatment plant, and 1 kg of dry weight is 1 kg of BOD, and 1 kg of BOD is required to process 1 kwh. In addition, it takes about 40 billion won, whereas if anaerobic treatment is performed on-site, it is possible to use 95 billion won worth of methane gas (manipulation of wastewater treatment unit in a four-way station outside of Seomyung, SciTech 1998, p589).

The energy required for this process is as follows. Based on 100 households, the grinders installed in each home are negligible because they usually run 3/4 hp for about a minute a day. The solid-liquid separator B is 1 / 2hp, and the operating time is about 8 hours, and the mixing pump of the anaerobic reactor is 1 / 2hp and 4 hours, and the total power consumption is less than 5kwh / day. The heat and heat losses of the anaerobic reactor are largely lost to heat, but in the spring and autumn, 82 and 87% of the production is surplus calories, respectively. Compared to the consumption of food waste by 300 ~ 13,415 won per household, the method of the present invention is the lowest level of less than 150 won per month (Park, Soon-Nam et al., Korea Society of Waste Management, 2002 Fall Conference) , p291-294).

As described above in detail a specific part of the content of the present invention, for those skilled in the art, such a specific description is only a preferred embodiment, which is not limited by the scope of the present invention Will be obvious. Thus, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

Accordingly, the present inventors devised a method for solving the disadvantages of the prior art as described above, and devised a method for completely extinguishing food waste at the generation site even with a small-capacity device regardless of whether or not a separate pipe is installed and to complete the present invention. It became.

After all, the main object of the present invention is to provide a method for treating food waste in a form that does not require reprocessing of residues at the generation site. The generation site is not far from the kitchen. The private / row house is located in the residential area, the apartment is in the basement or complex in the unit building, and the group cooking facility is close to the place of occurrence. It means where you hold.

That is, the present invention (1) immediately stored in the kitchen, such as present as soon as possible to prevent the corruption and odor smells to transport to the processing place within a minimum time; (2) after separating food waste and sewage before and after transportation to reduce the amount; (3) Minimize the space used for food waste disposal using high-performance, high-efficiency bioreactors to accommodate small spaces such as the remaining space of existing apartments in consideration of the narrow space of apartments and large restaurants; (4) converting food waste into gases such as methane gas (CH ₄ ), carbon dioxide (CO ₂ ) and treated water, such that the results are environmentally friendly so as not to cause secondary pollution such as odors; (5) Finally, it is aimed at making these treatment methods more economical and convenient in terms of energy use or annual treatment cost than conventional methods.

In order to achieve the above object, the present invention provides a first embodiment, (a) pulverizing food waste using a grinder installed at the bottom of the kitchen sink; (b) separating the kitchen sewage and the crushed food waste using the solid-liquid separator A installed downstream of the grinder, wherein the solid-liquid separator A has a food waste pipe (5) and a sewage pipe (6) for selection valve (4). It has a structure connected to, so that when the grinder (2) does not operate so that kitchen sewage is transferred to the sewage-only sewage pipe, when the grinder is operated, the crushed food waste is dedicated to food waste with a small amount of kitchen water Allowing the pipe to be transferred to the secondary processing device through the pipe; And (c) provides a method for treating the food waste in the group residential facilities or group cooking facilities comprising the secondary processing of the food waste pulverized in the secondary treatment device at the generation site.

According to the first embodiment of the present invention, before transporting the food waste separated from the solid-liquid separator A to the secondary processing apparatus, the solid-liquid separator B of the cylindrical screen method, the flat screen method or the filter method is used for transporting the food waste. Separating the kitchen sewage may be characterized in that it further comprises.

The present invention also provides a second embodiment, comprising the steps of: (a) crushing food waste using a grinder installed at the bottom of the kitchen sink; (b) transferring the pulverized food waste to the solid-liquid separator B of a cylindrical screen method, a flat screen method or a filter method using kitchen water; (c) separating a large amount of sewage and ground food waste using the solid-liquid separator B; (d) transferring the separated sewage to sewage pipes and transferring food waste to a secondary treatment device; And (e) provides a method for treating the food waste in the group residential facilities or group cooking facilities comprising the secondary processing of the food waste pulverized in the secondary treatment apparatus at the generation site.

The present invention also provides a third embodiment, (a) by installing a separate food waste pipe other than the sewage pipe, to separate the food waste and kitchen sewage, the kitchen waste is transferred to the sewage pipe, food waste is kitchen sink Grinding using a grinder installed at the bottom; (b) transferring the pulverized food waste to a solid-liquid separator B of a cylindrical screen method, a flat screen method or a filter method using a small amount of kitchen sewage; (c) separating kitchen sewage and food waste from the mixture of kitchen sewage and ground food waste discharged from various households using the solid-liquid separator B; (d) transferring the separated kitchen sewage to a sewage pipe, and transporting food waste to a secondary treatment device; And (e) provides a method for treating the food waste in the group residential facilities or group cooking facilities comprising the secondary processing of the food waste pulverized in the secondary treatment apparatus at the generation site.

In the present invention, the secondary treatment device means a biological treatment facility, a septic tank, an external discharge facility, a drying facility, or a recycling treatment facility, and the biological treatment is preferably a method of combining anaerobic treatment or anaerobic and aerobic treatment.

In the present invention, the secondary treatment device is a food waste inlet valve 12, the anaerobic reaction tank 19 of the microbial recycle type filled with a porous ceramic carrier, and the aerobic aerobic type of microbial recycled filled with a porous ceramic carrier Reactor 20, slurry circulation pump 21, apparatus 23 for injecting air into the aerobic reactor and gas discharge pipe for discharging methane gas generated by anaerobic treatment and carbon dioxide generated by aerobic treatment ( 24), it may be characterized in that it is provided with a temperature control device 22 and a sewage discharge valve 15 to maintain the temperature of the treatment device using the generated methane gas.

The cylindrical screen solid-liquid separator B is a cylindrical screen in which a pipe having a mesh size of 0.02-2 mm for separating pulverized food waste and sewage and a mesh (2) for separating pulverized food waste and sewage (Cylinder Screen B) 11), the motor 13 for rotating the cylindrical screen, the separated sewage storage tank 14, the discharge valve 15 and the sewer pipe (8) for discharging the sewage and food waste solids separated from the sewage in the cylindrical screen It may be characterized in that it comprises a means 12 for introducing into the secondary processing device (7).

The present invention also provides a tubular screen (11) in which a pipe (3) into which crushed food waste and sewage flows and a mesh having a mesh size of 0.02 to 2 mm for separating crushed food waste and sewage are cylindrically rolled, The motor 13 for rotating the cylindrical screen, the storage tank 14 of the separated sewage, the discharge valve 15 and the sewage pipe 8 for discharging the sewage and the food waste solids separated from the sewage in the cylindrical screen secondary It provides a device for separating wastewater and solids from food waste, characterized in that it comprises a means (12) for feeding into the processing device (7).

[Comparison with Existing Treatment Methods]

In Korea, the conventional method of treating food waste is to manually separate food waste from the source and collect it by manpower, then transport it to the treatment facility by vehicle for treatment, and sewage is separated from the source and sewage pipes are sent to the sewage treatment plant. Discharged (FIG. 1B). In the United States, food wastes that are ground using a grinder (disposer) are transported from the kitchen along with kitchen sewage to sewage treatment plants via sewer pipes (FIG. 1C). This method is not allowed in Korea, but is limited in Japan, because the existing city sewer pipe is narrow and the capacity of sewage treatment plant is insufficient.

The method of the present invention (FIG. 1A) is a method of crushing food waste in a kitchen of a residential or cooking facility and transporting it to a treatment plant not far from the source, and then processing it in a secondary treatment device such as anaerobic and / or aerobic fermentation. to be.

This is different from the method of feeding, composting, and anaerobic treatment after collecting and transporting to several treatment sites at the site, and treating them directly at the site without collecting and transporting. Disposal of food wastes by disposers and transporting them to the sewage treatment plant along with kitchen or household sewage is a practice in most US households.

The biggest feature of the present invention is to separate the sewage and pulverized food waste using a specific solid-liquid separator, the separated sewage is discharged to the sewage pipe to maintain the water quality in the state before mixing the food waste, the separated Food waste is treated at the production site using a small capacity secondary treatment device. In general, considering that the ratio of crushed food waste mixed with kitchen water or household sewage in one household is 1/250 to 1/500, the second throughput is 2 to 10: 1 can be reduced to around. In other words, the sewage separated using the solid-liquid separator is discharged to be clean or at least the same as before mixing the crushed food waste through a simple treatment, and to process only a small volume of separated food waste.

For example, if the separated food waste is treated by anaerobic fermentation, 100 household apartments have 50 ^~ 70M ³ of daily sewage, whereas the volume of separated food is about 200L / day, which is the basement or surrounding area. Even in a small place on a horizontal scale, it can be completely extinguished in a form that smells and by-products hardly occur.

[Method by separation method after grinding]

Fig. 2 shows various methods of separating the crushed food waste and sewage in the process of transferring the crushed food waste to the treatment site immediately after occurrence. Method A shows a first embodiment according to the present invention, wherein each of the home kitchen sink (1) is installed at the bottom of the crusher (2) and the solid-liquid separator A, the solid-liquid separator A is a food waste pipe (5) And the sewage pipe for exclusive use of sewage (6) has a structure connected to the selection valve (4), so that the kitchen sewage is transferred to the sewage pipe for sewage when the grinder does not operate, the crushed food waste when the grinder is operated Has a function to be transported through the food waste pipe with a small amount of kitchen water (FIG. 5). The food waste is crushed by using the grinder, and the crushed food waste is separated from a large amount of kitchen sewage through the solid-liquid separator A and transferred to the secondary treatment apparatus 7. The food waste separated by solid-liquid separator A in each household contains a small amount of kitchen sewage, and the total amount of sewage can be increased if the total of the waste-liquid separator A in each household in the apartment is combined. In order to further reduce the capacity of the secondary treatment device, a solid-liquid separator B of cylindrical screen type, flat screen type or filter type is installed near the secondary treatment device, and then the kitchen sewage used for transporting food waste from the solid-liquid separator B is used. It is preferable to further separate and then transfer to the secondary treatment apparatus.

Method B shows a second embodiment according to the present invention, and collects sewage and food waste generated in various homes, and then sewage and food waste using a solid-liquid separator B of a cylindrical screen method, a flat screen method or a filter method. The sewage is separated and transported to sewage pipe, and the food waste is transferred to the secondary treatment device.

Method C shows a third embodiment according to the present invention, by installing the food waste inlet and a separate pipe in the kitchen to discharge the food waste in the form of pulverized through a grinder installed downstream of the dedicated inlet, kitchen sewage Discharge directly to the sewer through the existing sewer. In the case of Method C, as in Method A, in order to further reduce the capacity of the secondary treatment apparatus, a solid-state separator B of cylindrical screen, flat screen or filter type is installed near the secondary treatment apparatus, and then It is preferable to further separate kitchen sewage used for transporting food waste, and then transfer the separated food waste to a secondary treatment device.

Method A and Method C use food waste pipes, which means that only a small amount of sewage is needed to be transported and not mixed with sewage after the food waste is crushed. No plumbing is required, so it can be applied to existing apartments. Instead, food waste is mixed in kitchen sewage at a rate of 1/200 to 1/300, or FIG. As shown in Fig. 3, food waste is diluted and transported at a rate of 1/500 to 1/800 in household sewage where bath and washing water are combined with kitchen sewage. It is necessary to treat not worse than water quality. In both cases, the crushed food waste separated from sewage is in the form of a slurry having a water content of about 90 to 95%, and its volume is about 2 to 5 times as original. In particular, in the case of Method B, the volume is reduced to 1/100 to 1/250, so that the treatment can be performed on the site near the occurrence place such as Method A and Method C.

[Process after separation]

Fig. 4 shows the specific method by treatment after separation.

In Method 1, sewage and food waste are separated through solid-liquid separator A, and sewage is transferred to sewage pipes, and the food waste is passed through a liquid biological treatment device, and a small portion of the remaining liquid is discharged to the sewer pipe through a water purification device, or Use for other purposes. In Method 2, sewage and food waste are separated through solid-liquid separator B, and sewage is transferred to a sewer pipe, and food waste is transferred to a septic tank and disposed of together with the manure. If food waste enters the septic tank, it will be necessary to increase the capacity of the septic tank in order to dispose of additional organic matter. However, since a small amount of high concentration organic matter is introduced, the hydraulic retention time in the septic tank does not change. In Method 3, sewage and food waste are separated through confession separator B, and the waste water is transferred to sewage pipes, and the food waste is transferred to storage facilities for composting, feed or drying, recycling, or discharged to the outside. Method 3 is characterized by the presence of solid residues. For reference, Method 1 does not require the treatment of solid residues.

[Solid-liquid Separator]

Specific solid-liquid separation method used in the present invention is shown in FIG. The method of separating sewage from sewage using solid-liquid separator A of 5 and the sewage pipe of the sewage from various households are shown in FIG. There is a method of separating sewage and food waste using the solid-liquid separator B of 6.

In the present invention, the solid-liquid separator A is a small-capacity separator installed in the kitchen of each household, and the solid-liquid separator B is installed near the secondary treatment unit to combine food waste from several households, and then separate the sewage from the sewage. It is a large capacity separating device. Solid-liquid separator B may be installed together near the biological treatment plant, for example, if the biological treatment plant is in the basement of the apartment.

Fig. 5 shows the solid-liquid separator A installed in the kitchen of each household that separates kitchen sewage and food waste. When the grinder is not operated, the valve 4 is closed so that the lake is not discharged to the food waste pipe 5. A, the valve is opened only when the grinder is operated so that the crushed food waste is conveyed through the food waste processing pipe, and it is preferable to add some water to facilitate transportation. Fig. The solid-liquid separator B of 6A-6C is a device for separating crushed food waste mixed in wastewater corresponding to hundreds to thousands of times the amount of food waste. Sewage from households usually includes kitchen sewage, bath sewage, and laundry sewage, and their total amount is 500 to 800 times that of food waste.

In 100-generation apartments, 70 tons (100x3.5x200L) of water can be used per day, and 87.5 kg (100x3.5x0.25) of food waste is mixed with 45 tons of water except 25 tons of toilet water. The proportion of food waste is 1/514. Although it is impossible to recover 100% of the food waste, it is not a big problem since the soluble organic matter and particulate food waste having a diameter of 5 mm or less are discharged from the kitchen even in a normal case without using a grinder.

Solid-liquid separator B takes most of these particulate organics, so it is not difficult to meet the chemical oxygen demand (COD) prior to discharge. That is, the COD of the treated effluent is expressed by period, for example, as "total amount of COD of discharged water = [FW + KW-particulate (FW + KW)] COD total amount ≤ original KW COD total amount" during the day. do.

Depending on how much particulate KW (Cdchen Waste) COD contained in the sewage prior to the crusher installation and the particulate food waste (FW) COD of the crushed food waste are recovered, it can be made less than the sewage COD before the crusher installation.

In general, centrifuges can separate large amounts in a short time, but they are not suitable for apartments of about 100 generations due to the high noise and power consumption. In consideration of this point, the present invention adopts a separator with little noise and low power consumption. Fig. 6 shows some examples of solid-liquid separator B. In order to recover large particles, it is preferable to use cylindrical screen method (FIG. 6A) and flat screen method (FIG. 6B). It is preferable to use a filter method (FIG. 6C) utilized. Since these separators may be blocked by cooking oil in some cases, they may be periodically washed after several hours of use, or alternately used by installing two.

[Biological processing device]

Since food waste is all biological material, it can be biologically decomposed. However, since it takes a long time to decompose such bones, shells, etc., it can be separated and collected before transport, and carbohydrates, fats, and proteins can all be converted to gas or water. This includes liquid as well as composting treatments.

Among the various biological treatment methods, a method that does not smell during treatment, has little residue or is easy to treat is considered. Therefore, the present invention adopts a liquid anaerobic treatment method that requires less energy and has no residues than composting or other methods in which solids remain as residues. When it is necessary to discharge better quality wastewater, it is preferable to use the method of combining said anaerobic treatment and aerobic treatment. Increasing BOD removal reduces food waste, resulting in less odor from organic acids and little residue.

In the present invention, it was aimed at treating the odor as well as treating the discharged water quality to the outside. Fig. 7 illustrates a biological treatment device used in the present invention to achieve the above object. The biological treatment unit has built-in anaerobic and aerobic reaction towers, which have the effect of recirculating microorganisms and at the same time have the ability to purify effluents highly. In addition, methane gas generated in the biological treatment device was used to maintain the temperature of the reactor (see Example 6),

Energy Consumption of Food Waste Treatment Apparatus According to the Present Invention

It was examined whether the treatment method of the present invention is economical and convenient in terms of energy use and annual treatment cost than conventional methods. In other words, water, chemicals, energy, and treatment sites required for the treatment were examined. The amount of additional water consumed by the grinder in the kitchen has already been increased by 2 to 3% of the total consumption, which has been studied in countries such as the United States, but compared to the enormous amount of water used for salt washing during the collection process. It is a national saving.

The energy consumption of the treatment device according to the present invention is expected to be used as a first grinder in the case of 100 apartments, usually 3/4 horsepower, the operating time is less than 1 minute a day can be said that the consumption is minimal The separator is also less than 5 kwh / day per 100 households.

In the case of the biological treatment unit, methane gas generated in the anaerobic digester is large, and 80% of energy remains even in the winter of 7 ° C. For small apartments less than 100 generations, a large surface area where heat can be lost is expected to consume some energy to maintain the winter temperature. The anaerobic treatment in the biological treatment system alone ensures that the water can be discharged to the outside, but if additional treatment is performed aerobicly to obtain better water quality, some additional power consumption is expected.

There is no medicine for food waste disposal in connection with the present invention. Spent grounds for 100 generations catch the throughput of an anaerobic reactor with 3kgBOD / m ³ .day, the amount of the dried organic matter to be 17.5kg (87.5% x0.2), the volume of the processing apparatus is a 6m ³ degree. It can be installed because it requires only about 2 pyeong of the apartment basement or the surrounding area.

The present invention is a field treatment method considering the convenience and hygiene of the American style using the disposer, and the circumstances of the sewage and sewage treatment plants in Korea. The most basic concept is characterized in that food waste is transported from the kitchen where it is generated without human hands, and then biologically processed by separating food waste from a large amount of household sewage. This eliminates the need for large spaces, making it practical for small spaces such as apartments.

Small amounts of separated food waste are either completely extinguished in an anaerobic biotreatment plant or combined in a septic tank. In some cases, it is also possible to separate and reduce the amount of garbage to the outside for disposal and recycling by composting. In anaerobic treatment, food waste is ultimately converted to water, gas, and some microorganisms, but the microorganisms prevent the outflow to the outside, which causes them to extinguish themselves, so that the resultant discharged out of the reactor is at the level of kitchen sewage before the input of food waste. It consists of sewage with the main qualities and anaerobic treatment which is environmentally friendly. Methane gas generated from the treatment tank is used for the production of fuel and hot water for the insulation of the treatment tank itself, which can be said to have higher energy utilization than other methods of treating food waste.

As described and demonstrated in detail above, the present invention provides a method for treating hygienic and energy-saving treatment of large-scale residential facilities such as apartments, large cooking facilities such as universities, military units, or household food waste. It is effective to provide. The present invention has the advantage that the secondary treatment of the residue in the environmental treatment method does not have a small space, noise, smell, etc. above all, the on-site treatment facility. In the country as well, when the sewage treatment plant is treated with sewage, it uses aerobic methods and consumes a lot of energy.

In conclusion, the food waste disposal method according to the present invention enjoys the convenience and advantages of the American disposer system in the kitchen, but has the advantage of not additionally burdening food waste disposal in the existing sewage pipe or sewage terminal treatment process in Korea. It is expected to be very useful for changing the paradigm of processing.

Claims (7)

A method for treating food waste in a group residential or group cooking facility comprising the following steps: (a) crushing food waste using a grinder installed at the bottom of the kitchen sink; (b) separating the kitchen sewage and the crushed food waste using the solid-liquid separator A installed downstream of the grinder, wherein the solid-liquid separator A has a food waste pipe (5) and a sewage pipe (6) for selection valve (4). It has a structure connected to, so that when the grinder (2) does not operate so that kitchen sewage is transferred to the sewage-only sewage pipe, when the grinder is operated, the crushed food waste is dedicated to food waste with a small amount of kitchen water Allowing the pipe to be transferred to the secondary processing device through the pipe; And (C) secondary processing the food waste crushed in the secondary treatment device. According to claim 1, Before the food waste separated in the solid-liquid separator A to transfer to the secondary treatment device, the kitchen waste used for food waste transfer using a solid-liquid separator B of the cylindrical screen, flat screen or filter method Further comprising the step of separating. A method for treating food waste in a group residential or group cooking facility comprising the following steps: (a) crushing food waste using a grinder installed at the bottom of the kitchen sink; (b) transferring the pulverized food waste to the solid-liquid separator B of a cylindrical screen method, a flat screen method or a filter method using kitchen water; (c) separating a large amount of sewage and ground food waste using the solid-liquid separator B; (d) transferring the separated sewage to sewage pipes and transferring food waste to a secondary treatment device; And (e) secondary processing the food waste pulverized in the secondary processing apparatus. A method for treating food waste in a group residential or group cooking facility comprising the following steps: (a) installing a separate food waste pipe in addition to the sewage pipe, separating and discharging the food waste and kitchen sewage, transferring the kitchen sewage to the sewage pipe, and crushing the food waste using a grinder installed at the bottom of the kitchen sink; (b) transferring the pulverized food waste to a solid-liquid separator B of a cylindrical screen method, a flat screen method or a filter method using a small amount of kitchen sewage; (c) separating kitchen sewage and food waste from the mixture of kitchen sewage and ground food waste discharged from various households using the solid-liquid separator B; (d) transferring the separated kitchen sewage to a sewage pipe, and transporting food waste to a secondary treatment device; And (e) secondary processing the food waste pulverized in the secondary processing apparatus. 5. The cylindrical screen type solid-liquid separator B according to any one of claims 2 to 4, wherein the mesh (3) for separating the crushed food waste and sewage and the mesh of 0.02 to 2 mm for separating the crushed food waste and filthy water. Cylindrical screen 11 in which a mesh having a size is rolled into a cylinder, a motor 13 for rotating the cylindrical screen, a reservoir 14 for sewage sewage, a discharge valve 15 for discharging sewage and a sewer pipe 8 And means (12) for feeding the food waste solids separated from the sewage in the cylindrical screen into the secondary processing device (7). The secondary treatment apparatus according to claim 1, 3 or 4, wherein the secondary treatment apparatus comprises a food waste inlet valve 12, an anaerobic reaction tank 19 in which a microorganism is recycled filled with a porous ceramic carrier, and a porous ceramic carrier. Generated by the aerobic reactor 20 in the form of recirculating microorganisms, the slurry circulation pump 21, the apparatus 23 for injecting air into the aerobic reactor and the methane gas generated by the anaerobic treatment and aerobic treatment A gas discharge pipe (24) for discharging the carbon dioxide, and a thermostat (22) and a sewage discharge valve (15) for maintaining the temperature of the treatment device using the generated methane gas. Pipe (3) into which crushed food waste and sewage flows, and a cylindrical screen (11) having a mesh size of 0.02 to 2 mm to separate the crushed food waste and sewage into a cylindrical shape, rotating the cylindrical screen Secondary treatment device (7) to the motor 13, the sewage reservoir 14 of the sewage, the discharge valve 15 and the sewer pipe (8) for discharging sewage and the food waste solids separated from the sewage in the cylindrical screen Apparatus for separating the sewage and solids from the food waste, characterized in that it comprises a means for injecting (12).