KR100949246B1 - Method for proessing the orgnic scrapped materials - Google Patents

Abstract

Organic waste treatment method according to the present invention, the step of putting the organic waste in the storage hopper for storing the organic waste and temporarily storing the organic waste in the storage hopper, the step of separately sorting the vinyl mixed with the organic waste, vinyl and Dehydrating and separating the leachate of the selected organic waste, treating the leachate, and drying the separated organic waste to extract solids. In addition, the step of treating the leachate, the step of removing the oil by receiving the leachate, decomposing the organic material from the leachate from which the oil is removed, generating methane gas, and purifying the leachate from which the organic material is decomposed and discharged It includes a step.

Food waste, organic waste, oil, leachate, methane, decomposition, purification

Description

Organic waste disposal method {Method for proessing the orgnic scrapped materials}

The present invention relates to a method for treating organic waste, and more particularly, to purify and treat odors, leachate, etc. generated by corrosion of organic waste such as food waste and livestock fractions buried underground, and accordingly In addition to using the inevitably generated solids as a powdery fertilizer, the present invention relates to a method for producing a methane gas.

Organic wastes (food waste, livestock waste, etc.), which are mostly produced at home, large restaurants, livestock farms, and food processing companies, account for most of Korea's waste generation (about 30%). .

However, despite the enormous social costs caused by these wastes, the amount is still increasing due to the improvement of living standards and the acceleration of the industry.

On the other hand, most of the disposal methods of household waste and industrial waste generated in this way are incineration methods for burning waste and landfill methods for burying waste in designated places.

In the case of disposal of waste by the above incineration method, the initial facility investment cost is high along with the limitation of the processing capacity, and the waste disposal by using the landfill method is mostly occupied until the waste gas is incinerated.

Conventional landfill facilities install vertical order walls and embankments along the side circumference and deeply dig the bottom surface, and install the bottom order layer, and install the leachate collection pipe on the bottom order layer or install the bottom order layer inclined toward the sump. Leachate, such as wastewater from the buried landfill, is introduced into the sump along the leachate collection pipe or inclined bottom drainage layer, and the leachate temporarily stored in the sump is sent to a nearby sewage treatment plant through a transfer pipe for purification. After that, only purified water is discharged into the stream.

However, especially when precipitation increases rapidly due to torrential rains during the rainy season, the leachate temporarily collected in the sump is not immediately purified but must be transferred to a nearby sewage treatment plant via a transfer pipe and then purified. If the leachate in excess of the capacity of the terminal treatment plant is supplied, the leachate may be incapable of treating the leachate, and the leachate overflows from the sump and leaks to the part between the vertical water tank and the sump and flows out to the outside. There was a problem that the soil or rivers around the landfill facility is polluted.

In addition, in order to treat leachate and general domestic sewage discharged from landfill as mentioned above, the pollution level of leachate should be similar to that of domestic sewage before introducing leachate, which has a more serious pollutant concentration than domestic sewage, to the sewage treatment plant. After adding a large amount of chemicals, it has to be introduced into the sewage terminal treatment plant, there is a problem in that the cost of treating the sludges is high due to the large amount of chemicals and a large amount of sludge is generated accordingly.

The present invention has been made in view of the above point, and purifies the odor, leaching water, etc. generated by the corrosion of organic waste such as food waste and livestock powder, and thus inevitably generates solids In addition to using as a fertilizer raw material, the object is to provide a method for producing methane gas by purifying the leachate.

The organic waste treatment method according to the present invention for achieving the above object comprises the steps of: a) putting the organic waste in the storage hopper for storing the organic waste, and temporarily storing the organic waste in the storage hopper; b) separating the vinyls mixed with the organic waste separately; c) dehydrating and separating the vinyls and the leachate of the selected organic wastes; d) treating leachate, d1) removing leachate by receiving leachate discharged from the organic waste stored in the storage hopper in step a) and leachate dehydrated in step c), and d2) A leachate treatment step of decomposing organic matters from the removed leachate and generating methane gas, and d3) purifying and discharging the leachate from which the organic matter is decomposed; And e) drying the organic waste from which the leachate is separated to extract solids.

The step d1) includes the step of removing the sludge from the leachate by passing the introduced leachate through the grid network structure, and removing the oil from the leachate from which the sludge is removed by the oil removal device and the combination treatment device. It is desirable to.

In the step d2), fermentative decomposition of the large molecular organic material contained in the oil-leached leachate into small molecular organic material is carried out by fermentative decomposition, and the small molecular organic material is decomposed by biological decomposition. It is preferable to include the step of generating methane gas in the decomposition process, and the step of removing the organic substances remaining in the leachate and ammonia, nitrogen compounds and residual fluoride.

Preferably, the step d3) includes the step of filtering the leachate through a microbial decomposition and microbial membrane, purifying the leachate using reverse osmosis, and discharging the leachate.

The step e) includes supplying heat to the organic wastes and drying to extract solids, collecting and deodorizing odor generated during the drying process, and selecting solid wastes from the solids. It is preferable.

According to the present invention, it is preferable to use the methane gas discharged in the step d) as a heat source of the boiler for drying the organic waste in the step e).

According to the present invention, the leachate and odor generated in the treatment of organic waste such as food waste, livestock fractions, and the like can be effectively treated, and the solids generated inevitably can be used as powdered fertilizer fuels. In particular, by treating the leachate completely, it is effective to increase the quality of the effluent. In addition, methane gas is generated during the leachate treatment process, and the generated methane gas is used as fuel for boilers without being discharged to the outside. It is effective to greatly reduce the.

The above objects, features and other advantages of the present invention will become more apparent by describing the preferred embodiments of the present invention in detail with reference to the accompanying drawings. Hereinafter, a method for treating organic waste according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The organic waste treatment method according to the present invention is characterized by treating leachate generated by corrosion of garbage and wastes buried underground, and thus, inevitably producing solids produced as powder fertilizers.

Referring to Figure 1, the organic waste treatment method according to the invention, the step of putting the organic waste in the storage hopper for storing the organic waste, and temporarily storing the organic waste in the storage hopper (S10), the organic waste and Separately sorting the mixed vinyls (S20), dehydrating and separating the leachate of the vinyl and the selected organic waste (S30), to remove the oil by the inflow of leachate and decompose the organic material from the leachate from which the oil is removed The leachate treatment step (S40) for generating methane gas and purifying and leaching the leachate, and drying the organic waste from which the leachate is separated, characterized in that it comprises the step of extracting a solid (S50).

First, the step "S10", the step of storing and storing the organic waste in the storage hopper for storing the weighed organic waste, the organic waste usually transported in a large tank lorry, homes, large restaurants, livestock farms, food processing companies As food waste, livestock waste, etc. mainly generated from the back, before weighing the storage hopper, the weight of the pure organic waste minus the weight of the large tank lorry is measured. The method of weighing here does not need to be particularly limited, and in general, a weighing method in which a large tank lorry is movable is preferable, and this is also a method of measuring a load weight of a cargo truck on a bridge or the like.

In addition, the weighed large tanker drops the accumulated organic waste into the storage hopper. The storage hopper is a type of tank for temporarily storing the organic waste, and an organic waste inlet opening and closing with a common hatch is installed on the ceiling to store the organic waste. On the other hand, when temporarily storing the organic waste in the storage hopper is generated some leachate, this leachate is introduced into the "S40" step for treatment.

Next, in the step "S20", it is a step of separately sorting the vinyls mixed with the organic waste, but since the separate collection of foods has not been made yet, the organic waste is transported in the home or restaurant, etc. As a means to do this, sealing of vinyl or the like can be used. Therefore, it is necessary to separate the plastic bags and the like from the organic wastes. The storage hopper of the step "S10" is provided with an inclined screw conveyor, the plastic bag is crushed while the screw of the inclined screw conveyor is driven, separated from the organic waste and collected separately.

Next, in the step "S30", as a step of dehydrating the leachate of the plastic bag and the selected organic waste, the leachate not removed in the "S10" step and the leachate remaining in the organic waste separated from the vinyl are dehydrated. . Usually, organic conveyors are transported into the dehydrator by a conveying conveyor. The inner tank of the dehydrator rotates and dehydrates. The leachate thus dewatered and separated from the organic waste is introduced into the "S40" stage for treatment.

Next, the leachate treatment step (S40), the step of removing the oil by receiving the leachate naturally discharged from the organic waste stored in the storage hopper of the "S10" step and the leachate dehydrated in the "S30" step (S410), Decomposing the organic material from the leachate from which the oil is removed and generating methane gas (S420), and purifying and discharging the leachate from which the organic material is decomposed (S430). This will be described in detail with reference to FIG. 2.

First, the step "S410", the step of removing the sludge from the leachate by passing the introduced leachate through the grid structure (S411), and the leachate from which the sludge is removed by the gravity separation oil and water separator and the combination treatment apparatus Removing oil from the step (S412).

Inflow of leachate is stored in a separate control tank, usually because the leachate has a pH of about 3, it is not particularly limited as long as it is a tank made of a material having acid resistance. The inlet shear of the adjustment tank has a grid structure to remove the leachate sludge (S411). Since the leachate contains sludge (foreign material) such as food waste, starch particles, suspended solids, and colloidal materials, coarse grids and thin grids are arranged in this order to remove the sludges and block other devices such as pumps in subsequent processes. To prevent. In addition, the adjustment tank may be further provided with a separate device for quantity adjustment. For example, an ordinary water gauge can be provided. A trap may be installed in the coordination tank, which uses oxygen in the air to oxidize a portion of the reducing material in the water.

On the other hand, the leachate stored in the adjustment tank is then subjected to the oil removal process, which is due to the oil removal device and the combination treatment device (S412). The oil removal apparatus may be applied in various ways and the scope of the present invention is not limited to any one, but the present embodiment applies a gravity separation oil / water separator. Gravity-separated oil / water separators are characterized by naturally separating water and oil by using oil-water density differences. On the other hand, it is as follows to explain the reason for removing the oil by using the two types of gravity separation oil-water separator and the combination treatment device.

The types of fats and oils contained in restaurants and homes are generally suspended, dispersed, emulsified, dissolved oils and solids. ) There are five.

First of all, suspended matter refers to an oil with a particle diameter of 30 μm or more and accounts for about 50-60% of the sewage contained. It floats above the sewage in the form of an oil film. Dispersed oil refers to an oil having a particle diameter of 1-30 μm and occupies about 35-45% of the contained sewage, which is dispersed in fine particles and suspended in water. Dispersed oils may be unstable and combine to form large particles, which may float on the surface, and may further change into emulsified oils. Emulsified oil refers to an oil whose particles have a diameter of 1 μm or less and occupies about 3-5% of the sewage contained. It is dispersed in the form of oil granules wrapped in water with extremely fine particles. It is floating. Dissolved oil is dispersed in the water body in the molecular state or chemical way, and oil and water are formed in the form of a homogenous body, which is very stable. The solids are formed by the particulate matter attached to the surface of the solid suspended solids and form about 2-6.5%.

Gravity-separated oil / water separator separates the floating oil and a part of the dispersed oil from the water by using the difference of the density of the water, and separates and floats the oil collected on the water surface. It is pushed back into the rescue device for recovery. If the temperature of water is relatively low, the oil may coagulate and lower its fluidity. Therefore, a heat aid is attached to the device to ensure the oil's fluidity.

In addition, the granulation treatment device uses a granulation flocculant, which is a polyacry lamide (PAM) fiber which is close to the oil and far from the water. ) And partly dissolved fine particles of oil (에 解 油) adhere to the coagulant. When it reaches a certain thickness, it is detached from the surface of the coagulant by the action of buoyancy and water to form large particles and floats on the water.

Next, the "S420" step is a fermentative decomposition step (S421) and a UASB reaction tank to decompose a large molecular organic material contained in the leachate from which the oil is removed using a acidification tank into a small molecular organic material. Decomposing the small molecule organic material using a biological decomposition method using the step of generating methane gas in this decomposition process (S422), and the remaining organic material in the leachate by using an A / O tank, ammonia, nitrogen compounds and The step S423 is carried out to remove the remaining inertia.

The leachate after removing the oil is subjected to an acidification step of increasing the oxygen content in the acidification tank. In the acidification step, the leachate thus far has a high organic matter content and a BOD / COD value, so that it is fermented and decomposed into an organic material having a small molecular weight by water decomposition. This is achieved by the water decomposition method, which is completed by Facultative Hydrolytic and Acidogenic Bacteria. It changes the large molecular organic material into small molecular organic material to improve the biochemical performance of filthy water and change it into an organic material that can dissolve insoluble organic material. It is based on contacting the post-treatment oxidized organic material which provides a product substrate (Stroma). The above process improves BOD / COD dimensions, which is beneficial for microbial decomposition during post-treatment, and also functions as an initial settling tank sludge digester and effectively removes COD and SS.

Following acidification, UASB (Up-flow Anaerobic Sludge Blanket) Through the reactor, the UASB reactor is repaired to decompose relatively small molecular organics in the leachate. The UASB process is to decompose organic materials by biological decomposition method which is anaerobic fermentation method at medium temperature (35 ± 3 ℃), and methane gas is generated during this decomposition process. Methane gas generated in the process can be used as a separate energy source through the desulfurization process.

Looking at the internal structure of the UASB reactor from bottom to top 1) Drainage 2) Sludge Blanket, 3) Sludge suspended bed, 4) Gas-liquid-sludge Separator, 5) Water outlet, 6) Methane outlet, 7) Methane gas It consists of a storage tank, 8) methane gas purifier, 9) methane gas combustion device, and the external structure of the UASB reactor from the outside to the inside, consisting of 1) insulation layer, 2) tank, and 3) antiseptic layer. . UASB reactor is highly adaptable to leachate and mostly removes COD and BOD. One kilogram of COD can produce 0.35-0.45 m ³ methane gas and the main components of methane gas are CH445-63% V and CO230-40% V. The generated methane gas can be stored in a wet low pressure reservoir after desulfurization removal and used as fuel. However, the UASB reactor cannot remove Nitrogen and Phosphorus in the leachate.

On the other hand, it is difficult to decompose in the leachate after the process further comprises the step of removing the remaining organic substances and ammonia, nitrogen compounds and residual ancillary (S423), which is A (Anoxic, oxygen deficiency) process and O process (Oxic , Oxygen).

The A / O (Anoxic / Oxic) process not only decomposes organic matter, but also removes nitrogen and phosphorus, and uses anaerobic hydrolysis as an active sludge pretreatment. In the anoxic stage, heterotrophic bacteria are transformed into organic acids by hydrolyzing suspended contaminants such as sewage, fiber, and carbohydrates and soluble organics in sewage, and converting them into organic acids. Decompose into molecular material and convert insoluble organic material into soluble material. As above, the anoxic hydrolyzed substance enters the aerobic reactor and improves the biochemical properties of sewage during aerobic treatment and improves the efficiency of oxygen. In the anoxic stage, heterotrophic bacteria ammoniate contaminants such as proteins and fats to favor nitrogen substances (NH3, NH4 +), and nitrification of autotrophic bacteria under oxygen supply conditions. ) Oxidizes NH3-N (NH4 +) to HO3- and returns it to group A under control of the return, and denitrification of heterotrophic bacteria under anaerobic conditions results in the removal of HO3- by molecular nitrogen (N2). ), C, N, O is completed in the ecology to realize the detoxification treatment of sewage.

Denitrification reaction is carried out by immobilizing a large amount of Facultative Denitrifying Bacteria in the anoxic and anaerobic phases.

In front of the anoxic tank, organic carbon in the sewage is used for denitrification bacteria to reduce the enrichment of organic substances in the aerobic reactor after the process, and the alkalinity produced by the denitrification process supplements the alkalinity required in the nitrification process in the aerobic reactor. Since the aerobic reaction is behind an anoxic bath, after the denitrification, the remaining organic pollutants are further removed to improve the water quality after treatment. The removal rate of BOD ₅ is over 90-95% and the removal rate of NH4 + is 95%.

Next, the step of removing the residual accompaniment may be further performed, which refers to microorganisms (eg, Bacillus, Pseudomonus, Pseudomonus azelaica, Azospirillium sp, etc.) and sludge present in the leachate.

Next, the "S430" step is the step of filtering the leachate through the microbial decomposition and microbial membrane (S431), purifying the leachate using a reverse osmosis method (S432) and the step of discharging the purified leachate (S433).

The "S431" step is mainly carried out by MBR, which is called a membrane bioreactor or membrane separation bioreactor, which can be configured primarily as an external installation. It is composed of a reactor, in which a large amount of microorganisms are in sufficient contact with the substrate in the bioreactor and undergoes metabolism through oxidative decomposition, maintaining their own growth and reproduction, while sufficiently decomposing organic pollutants. Membrane is subjected to solid / liquid separation of wastewater and sludge mixture through mechanical separation and confinement, and large molecule is concentrated and returned to the bioreactor to avoid microbial loss. , BOD, NH3-N, TKN, TP, SS, turbidity and oil content removal rate are high and water quality stability can be guaranteed. One MBR process does not require secondary sedimentation tanks, which has the advantage of having less mounting space than traditional activated sludge treatment methods, and the original facility can be expanded on demand, thus reducing the site area of the new construction process.

Reverse osmosis process (S432) is to remove the salt from the leachate using the reverse osmosis principle, and as a result, the leachate is reformed to a water quality capable of river discharge.

In addition, the purified water may be discharged and used as garden water and cleaning water, if necessary, as recycled resources (S433).

As described above, according to the present invention, the leachate is completely treated through various steps. On the other hand, if it is assumed that it is included in the national emission standard, some processes in operation can be omitted, such as a system in which a high operating cost such as a reverse osmosis system can be omitted. In addition, when the facility and the municipal wastewater treatment plant are in close proximity, the MBR system can be omitted if the living wastewater treatment plant is adjusted to the level of the domestic wastewater by physical and biological treatment methods.

Next, look at the step "S50", which is a step of extracting the solids by drying the organic waste separated from the leachate, by supplying heat to the organic wastes to dry and extract the solids (S51) and the drying process Collecting and deodorizing the odor generated in the step (S52), and the step of selecting a solid waste from the solid (S54).

In the drying step, organic waste is introduced into the dryer, and the dryer receives heat from a heat source such as a boiler to dry the organic waste, thereby removing moisture remaining in the organic waste, and consequently extracting solids.

On the other hand, in the drying step, due to the considerable heat applied to the organic waste, substances causing odors (for example, H ₂ S (egg rotting), NH ₃ (irritating odor), and CH ₃ SH (cabbage rot)) , CH ₃ SCH ₃ (vegetable rotting), and CH _3- (CH ₂ ) ₃ -CH ₂ SH (corrosive odor) are released into the atmosphere, so it is necessary to remove them. It can be connected to an external cooling tower by having a pipe-like configuration that can be a gas flow path of the gas, which causes odors to be dissolved in the water droplets generated when the cooling water and the cooling tower are driven, and consequently, the odor is removed. These cooling towers can be installed in a plurality of consecutively to increase the odor removal effect, but should be arranged in an appropriate number in consideration of the increase in the initial facility cost and maintenance costs. Residual odor components which are not removed by the tower can be supplied at the time of the air supply at the same time necessary for the complete combustion boiler operation separately provided that as a matter of course.

Finally, in the solid waste sorting step (S53), the solid wastes, such as spoons and chopsticks, bottle caps and bone fragments contained in the dried organic wastes are separated and the organic wastes are powdered fertilizer raw materials. Can be obtained.

Test Example  One

The amount of COD, BOD, ammonia, sludge and oil with respect to the leachate obtained by the embodiment of the present invention was measured and shown in Table 1 below.

COD (mg / L) BOD (mg / L) NH ₃ (mg / L) SS (mg / L) Oil (mg / L) pH Regulator inflow 140000 110000 1500 60000 10000 3 Oil removal device inflow 140000 110000 1500 60000 10000 3 outflow 100000 80000 1180 5000 400 5 Removal rate 28. 6% 27. 3% 21. 4% 91．7% 96.0% Incorporation inflow 100000 80000 1180 5000 400 5 outflow 90000 70000 1180 4500 40 5 Removal rate 10. 0% 12. 5% 0% 10. 0% 90% Oxidizer inflow 50000 40000 600 5000 40 5 outflow 55550 45720 765 5000 20 3 Removal rate -11．1% -14．3% -27．3% 0% 50% USAB inflow 55550 45720 765 5000 20 7 outflow 4000 1500 984 2780 10 7．5 Removal rate 92.8% 96．7% -28．6% 44. 4% 50. 0% Group A inflow 4000 1500 984 2780 10 7．5 outflow 2800 900 984 2000 8 7．5 Removal rate 30. 0% 40. 0% 0% 28. 1% 20. 0% Group O inflow 2800 900 984 2000 8 7．5 outflow 280 60 22 400 0 8.．0 Removal rate 90. 0% 93．3% 97.8% 77．8% 100% MBR inflow 280 60 20 400 0 8.．0 outflow 220 50 20 0．5 0 8.．0 Removal rate 21. 4% 16. 7% 0% 99.9% RO inflow 220 50 20 0．5 0 8.．0 outflow 50 10 2 0 0 6.．5 Removal rate 77．3 80．0% 90. 0% 100%

Referring to <Table 1>, it can be seen that the water quality of the leachate treated by the method of preparing the methane gas by purifying the leachate according to the present invention is improved.

Meanwhile, referring to FIGS. 1 and 2, methane gas is generated in the “S422” step, and the generated methane gas may be used as a separate energy source through a desulfurization process. According to the present invention, the generated methane gas further includes a step (S60) of using the fuel of the boiler for supplying heat in the drying step of the "S51". The generated methane gas can be stored in a wet low pressure storage tank after desulfurization removal and used as fuel for the boiler. Therefore, according to the present invention, by using the generated methane gas as a fuel of a boiler without discharging to the outside, it has a great effect on improving the environment, and also has the effect of greatly reducing the fuel cost, which occupies a large part of the maintenance cost of the food waste treatment process.

Although preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described specific embodiments. That is, those skilled in the art to which the present invention pertains can make many changes and modifications to the present invention without departing from the spirit and scope of the appended claims, and all such appropriate changes and modifications are possible. Equivalents should be considered to be within the scope of the present invention.

1 is a block flow diagram for explaining a method for treating organic waste according to an embodiment of the present invention;

2 is a detailed block flow diagram of the leachate treatment step of FIG.

Claims (6)

delete a) injecting organic waste into a storage hopper for storing organic waste and temporarily storing the organic waste in the storage hopper; b) separating the vinyls mixed with the organic waste separately; c) dehydrating and separating the vinyls and the leachate of the selected organic wastes; d) treating the leachate, and d1) the leachate by receiving the leachate discharged from the organic waste stored in the storage hopper in step a) and the leachate dehydrated in step c) and passing the leachate through the grid structure. Removing sludge from the sludge, removing oil from the leachate from which the sludge has been removed by means of an oil removal device and a condensation treatment device, and d2) decomposing organic matter from the leachate from which the oil is removed and further removing methane gas. And a leachate treatment step including d3) purifying and discharging the leachate in which the organic material is decomposed. And, e) drying the organic wastes from which the leachate is separated to extract solids. The method of claim 2, wherein the d2) step, Fermentatively decomposing the large molecular organic material contained in the oil-leached leachate into the water decomposition method of decomposing the small molecular organic material into the small molecular organic material, and decomposing the small molecular organic material by the biological decomposition method. Generating a gas, and removing organic matter remaining in the leachate, ammonia, nitrogen compounds and residual by-products. The method of claim 2, wherein the d3) step, And filtering the leachate through a microbial decomposition action and a microbial membrane, purifying the leachate using a reverse osmosis method, and discharging the purified leachate. The method of claim 2, wherein step e) Supplying heat to the organic wastes and drying to extract solids; collecting and deodorizing odors generated in the drying process; and sorting out solid wastes from the solids. Treatment method. The method of claim 2 or 3, The methane gas discharged in the step d) is used as a heat source of the boiler for drying the organic waste in the step e).

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