KR100663993B1 - Wastewater treatment method of food waste recycling process - Google Patents

Abstract

The present invention is a wastewater treatment method of the food waste recycling process to filter the wastewater generated in the process of recycling the food waste to recycle the solid food waste particles contained in the wastewater, and to discharge the filtered fresh water to the outside It is about.

To this end, the present invention comprises the steps of: depositing the wastewater generated in the process of recycling into a collecting tank to precipitate sludge, and injecting the liquid wastewater into the solid-liquid separator to perform primary separation; Inputting the separated liquid wastewater into a heater to heat the secondary liquid, and separating the heated wastewater into three phases of water, oil, and sludge cake by a centrifuge; Storing the secondary separated wastewater in an anaerobic digestion tank and injecting a flocculant into the stored wastewater to collect sludge in the wastewater; Conducting dehydration by passing the sludge-collected wastewater through a dehydrator, and performing secondary filtration by introducing wastewater generated by dehydration into a filter; After collecting the second filtered wastewater in the sump to perform the final precipitation, the present invention provides a wastewater treatment method of the food waste recycling process comprising the step of releasing the generated fresh water to the outside.

Description

Wastewater treatment method of food waste recycling process {SEWAGE CLEANING METHOD OF RESOURCE PROCESS FROM FOOD-WASTES}

1 is a block diagram of an apparatus for performing the wastewater treatment method according to the present invention.

2 is a cross-sectional view showing the actual configuration of the screw press in the configuration of FIG.

3 is a flow chart of the wastewater treatment process according to the present invention.

Figure 4 is an excerpt configuration of another embodiment of the present invention.

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

1: wastewater sump 2: drum screen

3: centrifuge 4, 5: vibrating screen

6, 7: steam stirring tank 8: three-phase separator

9: anaerobic digester 10: filter press

11: membrane filter 12: effluent sump

20: screw press 30: aeration unit

31, 32: aeration tank 33: oxygen supply

The present invention relates to a wastewater treatment apparatus. In detail, the wastewater treatment method of the food waste recycling process by filtering the wastewater generated in the process of recycling the food waste, recycling the solid food waste particles contained in the wastewater, and discharging the filtered fresh water to the outside. It is about.

Today's society is getting richer and richer with the rapid industrial development and the improvement of national income. These phenomena have gradually enriched the diet, which is a necessary condition for human life. Therefore, while the inability to normally eat food in the old declining life is reduced, the amount of food that is left unnecessarily on the enriched table is increasing.

Since these food wastes generate considerable leachate during landfill, which contaminates soil and groundwater, the government has banned dumping of marine wastes and landfills since 2005. In particular, since food waste contains a large amount of water, it causes odors as the water leaks to the outside, and inhabits pests and mice that transmit diseases caused by various germs, causing serious pollution of the surrounding environment. .

Accordingly, the food waste has been recycled and supplied in the form of compost for growing feed and various crops provided to various livestock or animals. The recycling of food waste has an excellent effect on reducing economic benefits and environmental pollution.

In order to recycle the food waste in the form of feed / compost as described above, the food is sterilized by heating, dried and crushed to go through the process of manufacturing. In this process, food waste is put into a hopper, and each process is performed by a crusher, a dehydrator, a vacuum cooker, a dryer, or a pulverizer to produce a feed / compost.

When such resources and work processes are carried out, a large amount of wastewater is generated from the processed food waste, which, when discharged to the outside, causes serious environmental pollution. Therefore, in order to prevent environmental pollution caused by the discharge of wastewater, the process of filtration of wastewater by fresh water is essentially required.

Conventionally, in order to treat the wastewater as described above, the wastewater generated in each working process is collected in a filtration apparatus and filtered, and then the filtered fresh water is discharged to the outside. At this time, the generated filtration material (sludge cake) is taken out of the filtration apparatus and disposed of.

The conventional process of treating wastewater by performing filtration as described above only performs a simple process of filtering wastewater and discarding the filtrate. Therefore, the waste of the filtrate generated during the wastewater treatment is a factor of secondary environmental pollution.

In addition, wastewater treatment that simply relies on filtration causes a problem that some components such as microorganism heavy metals, which cannot be filtered, remain in the wastewater and are difficult to be converted into fresh water having an ideal cleanliness.

The present invention has been invented to solve the above problems, by supplying the sludge cake generated after the filtration of waste water back to the recycling process, increasing the amount of feed / compost produced, heating to some microorganisms that can not be filtered, The aim is to provide a method for treating wastewater which can be filtered.

In order to achieve the above object, the present invention has the following features.

The present invention comprises the steps of storing the wastewater generated in the recycling process in the water collection tank to precipitate sludge, and injecting the liquid wastewater into the solid-liquid separator to perform primary separation; Inputting the separated liquid wastewater into a heater to heat the secondary liquid, and separating the heated wastewater into three phases of water, oil, and sludge cake by a centrifuge; Storing the secondary separated wastewater in an anaerobic digestion tank and injecting a flocculant into the stored wastewater to collect sludge in the wastewater; Conducting dehydration by passing the sludge-collected wastewater through a dehydrator, and performing secondary filtration by introducing wastewater generated by dehydration into a filter; And collecting the secondary filtered wastewater in a sump to perform final precipitation, and then discharging the generated fresh water to the outside.

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

1 is a block diagram of a device in which the wastewater treatment method according to the present invention is performed.

Referring to the drawings, the wastewater treatment apparatus according to the present invention is a wastewater collection tank (1), primary separation unit, primary filtration unit, heating unit, secondary separation unit, anaerobic digestion tank (9), dehydration unit, secondary filtration unit , Consisting of a discharge water collection tank (12). Here, each component is connected by a screw conveyor and a pipeline in which a vacuum pump or the like is installed, and the liquid in the wastewater in which the work is performed is transported through the pipeline, and the solid is transported through the screw conveyor.

The wastewater collection tank 1 is configured in the form of a container for storing and settling the wastewater generated during the recycling process. Such wastewater collection tank 1 is a preliminary configuration for improving the separation efficiency by sedimenting the sludge before the wastewater is delivered to the primary separation unit.

The primary separation unit is configured to separate and remove the solid material in the waste water transferred from the water collection tank (1). This primary separator is constituted by a drum screen 2 and a centrifuge 3.

The drum screen (2) is a device that is installed inside a plurality of perforated network to remove the relatively large solid material, such as vinyl introduced with the waste water through a perforated network of various specifications with each other.

The centrifuge 3 is commonly referred to as a "centrifugal concentrator" and is a device for separating sludge of small particles not removed from the drum screen 2. In particular, the centrifugal separator 3 performs high-speed rotation of approximately 3000 RPM to separate wastewater and sludge.

The primary filtration unit is configured to receive the waste water transferred from the centrifuge (3) to perform filtration by the filtration device. As the filtering device, vibration screens 4 and 5 through which wastewater passes through the mesh screen and filter the solid material are applied.

The vibration screens 4 and 5 may be installed in one or more numbers. In particular, when a plurality of mesh screens are installed, the particle size of the mesh screen is gradually narrowed, that is, for example, if the mesh screen particle size of the first vibrating screens 4 and 5 is 100 mesh, Mesh screen particle size is preferably configured to have a particle size of about 160 to gradually filter the fine solid material.

The heating unit is configured to heat the wastewater delivered by primary filtration. At this time, steam stirring tanks 7 and 8 are used as heating means. In particular, it is natural that the steam stirring tanks 7 and 8 are provided with stirring screws in the steam stirring tanks 7 and 8 to stir and heat the wastewater therein. The steam stirring tanks 7 and 8 maintain a constant concentration of wastewater, and are configured to increase the separation efficiency and purity of the refined oil after being injected into the secondary separator.

In particular, the steam stirring tank (7, 8) is preferably installed in more than one number. When a plurality of steam stirring tanks (7, 8) is installed, to increase the temperature for gradually heating the waste water to improve the efficiency of maintaining the concentration. For example, it is preferable that the initial heating temperature is heated at 50 ° C to 60 ° C, and the subsequent heating temperature is heated to 85 ° C to 90 ° C.

The secondary separator is configured to separate the wastewater delivered after being heated by the steam stirring tanks 7 and 8 into a solid and a liquid by a centrifuge. At this time, the three-phase separator 8 is applied to the centrifuge.

Such a three-phase separator is to perform the operation by separating the wastewater into water, oil, sludge cake three stages by high-speed rotation of approximately 6000RPM. At this time, the above-mentioned oil can be used mixed with the boiler oil, it is possible to utilize the resources. In particular, the oil can be applied as a raw material for the production of paint, and can also be applied as a secondary raw material of the maintenance plant is high utilization.

The anaerobic digestion tank 9 is configured in the form of a container in which the liquid wastewater is stored after centrifugation. Such anaerobic digestion tank 9 collects a small amount of sludge contained in the wastewater by adding a flocculant to the stored wastewater, thereby improving the efficiency for the subsequent dehydration step.

The dewatering unit receives wastewater in which sludge is collected in the anaerobic digestion tank (9), and the wastewater passes to the next secondary filtration unit, and is configured to dewater the sludge. Such dehydration is performed by the filter press 10. In particular, microorganisms, heavy metals, etc. are filtered to the sludge remaining by the dehydration process described above.

Here, the filter press 10 is a device that can reduce the cost of treatment by reducing the dewatering period of the sludge, as is known.

The secondary filtration unit is applied to the membrane filter (11). Such a membrane filter 11 is dehydrated in the filter press 10 to remove particles that are difficult to be filtered, such as microorganisms, heavy metals, and the like that are difficult to decompose, by forcing a membrane filter medium having ultra-fine pores by water pressure.

The discharge water collecting tank 12 is configured to collect the secondary filtered wastewater to perform the final precipitation, and to discharge the fresh water generated after the precipitation to the outside. The discharge water collection tank 12 is configured in the form of a container for temporarily storing the discharge water passed through the final membrane filter 11. At this time, in fact, the secondary filtered wastewater is already formed as fresh water, but is a device provided to realize a more ideal discharge standard by the precipitation of fine particles.

In such a configuration, the sludge separated from the solid in a specific component is supplied in the process of recycling food waste into feed / compost. At this time, the sludge is to use the screw press 20 to be manufactured into a sludge cake of a type more suitable for the recycling process.

2 is a cross-sectional view showing the actual configuration of the screw press in the above configuration.

Referring to the drawings, the screw press 20 is a solid and liquid in the aforementioned drum screen (2), centrifuge (3), electric screens (4, 5), three-phase separator (8), filter press (10) Configured to receive sludge from the separated wastewater.

In particular, the screw press 20 is provided with a screw 22 for conveying and stirring the inside of the cell 21 to be a case and pressurized sludge to one side. In particular, a filter net 23 for filtering wastewater flowing out of the sludge by pressurization is provided below the screw 22.

As a result, the screw press 20 as described above is transferred to a vacuum cooker (not shown) for implementing a recycling process by the sludge cake from which the waste water is discharged. In addition, the wastewater is again supplied to the vibrating screens 4 and 5 of the primary filtration unit to undergo wastewater treatment.

3 is a flow chart of a process in which wastewater is treated by the apparatus.

Referring to the drawings, in order to treat the wastewater generated during the recycling of food waste, first, when the wastewater is delivered through decanta to dehydrate and purify the solids in the recycling apparatus, the delivered wastewater is stored in the water collecting tank 1 ( S1). Thereafter, the stored waste water is precipitated sludge in the sump.

The wastewater collected as described above is introduced into the drum screen 2 and the centrifuge 3 which are solid-liquid separators for solid-liquid separation, and the first separation (solid-liquid separation) is performed (S2). Thereafter, the solid-liquid separated liquid wastewater is first filtered by a single or multiple drum screens 4 and 5, which are filters (S3).

The filtered wastewater is applied to the steam agitating tanks 7 and 8 by a heater and then heated inside the steam agitating tanks 7 and 8 (S4). The heated wastewater is introduced into a three-phase separator 8, which is a centrifuge, and a secondary separation process in which the wastewater is three-phase separated into water, oil, and sludge cake is performed (S5). At this time, the waste water (water) after the three-phase separation is a state in which most of the sludge is removed, the oil is used as boiler oil, paint manufacturing subsidiary materials, maintenance raw materials and the like as described above.

Thereafter, only water in the three-phase separated wastewater is stored in the anaerobic digestion tank 9, and when a flocculant is added to the stored wastewater, a small amount of sludge is collected (S6). In this way, the wastewater from which the sludge is collected is introduced into the filter press 10, which is a dehydrator, to perform dehydration (S7). At this time, the dehydration is high efficiency of dehydration because the sludge particles are already dehydrated by the collection of sludge in the anaerobic digestion tank (9).

The dewatered waste water is passed through the membrane system 11, which is a filter, and secondary filtration is performed (S8). At this time, the filtration by the membrane system 11 is carried out by forcibly passing through the membrane filter medium having ultra-fine pores of difficult-to-dissolve particles such as microorganisms, heavy metals, which are not filtered even in the process of normal filtration and three-phase separation.

Thereafter, the wastewater (virtually fresh water) in which the secondary filtration is performed is collected in the effluent collecting tank 12 (S9). This collection process is a process for discharging more ideal fresh water by finally settling the fine particles before discharging the fresh water.

In the above process, the sludge generated during the separation, filtration, and dehydration of wastewater is solid-liquid separated in the screw press 20, which is a solid-liquid separator, and then re-supplied in the reprocessing process as described above.

<Other Embodiments>

Figure 4 is an excerpt configuration diagram of another embodiment of the present invention.

Referring to the drawings, the wastewater treatment apparatus according to another embodiment shows a state in which the secondary filtration is performed by the activated sludge method in the original embodiment. The configuration for this suggests the configuration of the aeration unit 30 in place of the membrane filter 11 of the original embodiment.

The aeration unit 30 is composed of aeration tanks 31 and 32 in which waste water is stored and an oxygen supplier 33 installed in the aeration tank 31 to supply oxygen.

Such aeration tanks (31, 32) are divided into first and second aeration tanks (31, 32), and the wastewater is subjected to high load treatment in one aeration tank (31), and the high load treated wastewater is subjected to low load treatment in the other aeration tank. In the aeration tank 32 on the other side, the activated sludge is forcibly separated by a pressure flotation method and the like to purify the wastewater.

As described above, the present invention, by supplying the sludge cake generated in the waste water treatment process to the re-processing process, thereby increasing the amount of feed / compost produced during the recyclization process to obtain the effect of improving productivity.

In addition, the present invention has the effect of preventing the secondary environmental pollution factors by discharging the fresh water having an ideal cleanliness by heating, filtering to some microorganisms that can not be filtered.

Claims (3)

Storing the wastewater generated in the recycling process in the sump (1) to precipitate sludge, and performing a primary separation in which the solid matter in the wastewater is separated by a drum screen (2) and a centrifuge (3); Passing the waste water transferred from the centrifuge (3) and subjecting the solid material to vibration screens (4, 5) to perform primary filtration; Inputting the separated liquid wastewater into a heater to heat the secondary liquid, and separating the heated wastewater into three phases of water, oil, and sludge cake by a centrifuge; Storing the secondary separated wastewater in an anaerobic digestion tank (9), and adding a flocculant to the stored wastewater to collect sludge in the wastewater; Conducting dehydration by passing the sludge-collected wastewater through a dehydrator, and performing secondary filtration by introducing wastewater generated by dehydration into a filter; And collecting the secondary filtered wastewater in a water collecting tank (12) to perform final precipitation, and then discharging the generated fresh water to the outside. The method of claim 1, The sludge generated during the first separation, the first filtration and the dehydration process is separated by the drum screen (2) and the centrifuge (3), and then the wastewater which is a liquid is supplied to perform the process after the second filtration process again, The sludge cake as a solid is a wastewater treatment method of the food waste recycling process comprising the step of being re-supplied to the recycling process. The method of claim 1 or 2, wherein the secondary filtration process Wastewater treatment method of the food waste recycling process characterized in that the activated sludge method of performing aeration in the wastewater to perform the purified water treatment by the activated sludge.

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