KR101033618B1 - Apparatus for recycling of organic waste - Google Patents

Abstract

The present invention relates to an apparatus and method for recycling organic waste, which reduces the volume of the anaerobic digester by minimizing the water content of the solids supplied to the anaerobic digester by coagulating and dehydrating the organic waste, and does not require internal return of the digested sludge. The apparatus for recycling organic waste according to the present invention comprises a combination of crushing sorting means, dehydration means, dry anaerobic digester, composting means, and wastewater treatment device, wherein the dewatering means comprises: preliminary dehydration for separating organic waste into organic desorption liquid and preliminary solids. Means, primary dehydration means for separating the organic desorption liquid into a first dehydration liquid and a first solid substance, and primary coagulation dehydration means for separating the first dehydration liquid into a second dehydration liquid and a second solid substance using a coagulant. The dry anaerobic digester comprises a first solid and a second solid having a total solid concentration of at least 15%. It is characterized in that it serves to anaerobic digestion of the first solid and the second solid by receiving a solid.

Organic Waste, Dry Anaerobic Digester, Plasma Wastewater Treatment System

Description

Apparatus for recycling of organic waste

The present invention relates to an apparatus and method for recycling an organic waste, and more particularly, to coagulation and dehydration of organic waste to minimize the water content of the solids supplied to the anaerobic digester, thereby reducing the volume of the anaerobic digester and reducing the internal conveyance of the digested sludge. An apparatus and method for recycling an organic waste that is not required.

Recently, technologies for producing biogas such as methane by anaerobic digestion of organic waste such as food waste, livestock manure, and sewage sludge have been developed. Such a method of producing and using biogas from organic waste has been spotlighted in that it can reduce the load of environmental pollution in addition to using biogas as an energy source.

The method of recycling the organic waste is described in Korea Patent Registration No. 10-654656, Korea Patent Registration No. 10-679500, etc. Looking at the configuration of the conventional organic waste recycling apparatus as an example. As shown in FIG. 1, the conventional organic waste recycling apparatus includes an organic waste supply means 101, a shredding sorter 102, a digester supply part 103, an anaerobic digester 104, a sludge mixer 105, and a coagulation dehydration means ( 106) and the like.

Looking at the operation of the conventional organic waste recycling apparatus as described above, the organic wastes supplied by the organic waste supply means 101 is first removed from the waste by using the crush sorting unit 102, and then to the digester supply unit 103 Supplied. Then, paper sludge or the like is added to increase the total solid (TS) concentration and supply organic matter to the organic waste in the digester supply unit 103, and heat is applied by steam or the like to promote anaerobic digestion. The organic waste is supplied to the anaerobic digester 104. At this time, the water content of the organic wastes supplied to the anaerobic digester 104 is about 70 to 85%.

As described above, the organic waste supplied to the anaerobic digester 104 undergoes anaerobic digestion to generate biogas such as methane and generate digested sludge. The digested sludge is then passed to the sludge mixer 105 and mixed with certain subsidiary materials such as sawdust and ultimately composted. At this time, in addition to being supplied to the sludge mixer 105, the digested sludge is again supplied to the digester supply part 103 by an internal conveyance process. Accordingly, in the digester supply unit 103, the organic waste supplied through the crushing sorter 102 and the digested sludge discharged from the anaerobic digester 104 are mixed together. Here, the path through which the digestion sludge is internally conveyed to the digester supply part 103 may be a path supplied from the anaerobic digester 104 to the digester supply part 103 from the coagulation dehydration means 106 to the digester supply part 103. . That is, the digested sludge may be supplied to the digester supply unit 103 after coagulation and dehydration.

The reason for supplying the digested sludge to the anaerobic digestion tank 104 is to maintain the total solid concentration of the organic waste supplied to the anaerobic digestion tank 104 at a predetermined concentration or higher, and to allow contact with microorganisms. As described above, the water content of the organic waste in the anaerobic digestion tank 104 should be maintained at 70 to 85%. In order to maintain the water content of the organic waste, that is, the total solid concentration of the organic waste, the total solid concentration of the digested sludge is high. Supply (approximately 30% of the digested sludge) is essential.

In the conventional organic waste recycling apparatus as described above, it can be seen that the internal conveyance process of the digested sludge is essentially required. However, there is a disadvantage in that the volume of the anaerobic digester 104 increases as a certain amount of digested sludge is conveyed internally and supplied to the anaerobic digester 104.

The present invention has been made to solve the above problems, by minimizing the water content of the solids supplied to the anaerobic digester by coagulation and dehydration of the organic waste to reduce the volume of the anaerobic digester and does not require the internal return of the digestion sludge It is an object of the present invention to provide an apparatus and a method for the recycling of organic waste.

The organic waste recycling apparatus according to the present invention for achieving the above object is composed of a combination of crushing screening means, dewatering means, dry anaerobic digestion tank, composting means and waste water treatment device, the dewatering means, organic desorption liquid And preliminary dehydration means for separating the preliminary solid, the first dehydration means for separating the organic desorption liquid into a first dehydration liquid and a first solid material, and the first dehydration liquid using a flocculant to separate the second dehydration liquid and the second solid substance. It is composed of a primary flocculation dehydration means that is separated into, the dry anaerobic digestion tank receives the first solids and the second solids with a total solids concentration of 15% or more to serve to anaerobic digestion of the first solids and the second solids It is done.

The wastewater treatment device is composed of a wastewater pretreatment device and a plasma wastewater treatment device, characterized in that for treating the second dehydration liquid discharged by the primary flocculation dewatering means and the wastewater discharged from the dry anaerobic digestion tank. In this case, the plasma wastewater treatment apparatus includes a reactor providing a space for wastewater treatment, a quartz tube provided in the reactor, a coil provided around the quartz tube to generate plasma upon application of power, and to the coil. It may be configured to include a power supply for applying power. In addition, the wastewater pretreatment device may be configured as an upflow anaerobic wastewater treatment device.

A secondary dehydration means and a secondary flocculation dehydration means are further provided at a rear end of the dry anaerobic digestion tank, and the secondary dehydration means serves to dehydrate the digested sludge discharged from the dry anaerobic digestion tank, and the secondary flocculation dehydration means. Serves to coagulate and dehydrate the digested sludge dehydrated by the secondary dewatering means. In addition, one side of the dry anaerobic digestion tank may be further provided with a biogas collecting means for collecting the biogas generated from the dry anaerobic digestion tank.

The composting means is composed of a sludge mixer, a water control agent supply means and a composting tank, the sludge mixer is suitable for the digestion sludge supplied from the secondary dewatering means and the secondary flocculation dehydration means and the moisture control agent supplied from the moisture control agent supply means. It serves to mix, and the composting tank serves to ferment the mixture of the digested sludge and the moisture control agent.

In the method of recycling the organic waste according to the present invention, in the initial stage of operation of the dry anaerobic digestion tank, only 25 to 35% of the total amount of solids generated from the preliminary dehydration means, the primary dehydration means, and the primary flocculation dehydration means is used. It characterized in that the supply to. At this time, the remaining solids not supplied to the dry anaerobic digester are fed to the sludge mixer for composting.

The apparatus and method for recycling the organic waste according to the present invention has the following effects.

By supplying the solids with the minimum water content to the dry anaerobic digester, the sludge internal conveying process can be omitted, thereby minimizing the volume of the dry anaerobic digester and maintaining a high organic load, thereby increasing the volume of biomass. Gas can be generated. In addition, by digestive sludge discharged from the dry anaerobic digestion tank can be recycled as compost resources.

In addition, in consideration of stabilization of the dry anaerobic digester at the initial stage of operation of the dry anaerobic digester, only 25-35% of the total amount of solids is supplied to the dry anaerobic digester, and the remaining solids are discharged to the sludge mixer to apply the aerobic composting process. Organic waste (contracted throughput) can be processed and operated normally. In addition, stabilization of the dry anaerobic digester can be effectively achieved by increasing the amount of solids supplied to the dry anaerobic digester.

Hereinafter, an apparatus and method for recycling organic waste according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. 2 is a block diagram of an apparatus for recycling organic waste according to an embodiment of the present invention.

As shown in FIG. 2, the apparatus for recycling organic waste according to an embodiment of the present invention is composed of a combination of crushing sorting means 220, dehydration means, dry anaerobic digestion tank 240, composting means, and wastewater treatment apparatus. .

The shredding sorting means 220 receives and shreds the organic waste collected from the organic waste supplying means 210 provided at the front end, and serves to remove the impurities contained in the organic waste.

The dewatering means is specifically composed of a preliminary dewatering means 231, the primary dewatering means 232 and the primary coagulation dehydration means 233. The preliminary dewatering means 231 serves to separate the organic waste from which the contaminants have been removed to separate the organic desorption solution and the solids, and the primary dewatering means 232 is organically separated by the preliminary dewatering means 231. It serves to separate the desorption liquid into the dehydration liquid and solids, and the primary coagulation dehydration means 233 serves to separate the dehydration liquid separated through the primary dehydration means 232 into the dehydration liquid and solids. do. Here, for convenience of explanation, hereinafter, the solid separated by the preliminary dewatering means 231 is referred to as a preliminary solid, and the dehydration liquid and the solid separated by the primary dewatering means 232 are respectively the first dehydration liquid and the first dehydration liquid. It is called a solid and the dehydration liquid and the solid separated by the primary coagulation dehydration means 233 will be referred to as a second dehydration liquid and a second solid substance, respectively.

The preliminary dehydration means 231, the primary dehydration means 232 and the primary coagulation dehydration means 233 may be implemented as a centrifugal separator capable of solid-liquid separation, the primary coagulation dehydration means 233 is a first In addition to the centrifugal separator for performing physical solid-liquid separation with respect to the dehydration liquid, it comprises a coagulant administration means (not shown) for performing a chemical solid-liquid separation of the first dehydration liquid by administering a flocculant to the first dehydration liquid.

As such, the application of preliminary dehydration, primary dehydration and primary coagulation dehydration for organic wastes results in biochemical oxygen demand (BOD), chemical oxygen demand (COD), nitrogen and phosphorus concentrations (TN). , TP) and suspended solids (SS) can be significantly reduced. Table 1 below shows the primary dehydration process and the primary coagulation dehydration process by the primary dehydration means 232 and the primary coagulation dehydration means 233 of the organic desorption liquid separated by the preliminary dehydration means 231. The experimental result is applied. As shown in Table 1, it can be seen that BOD, COD, etc. are significantly lowered after the first dehydration process is applied, and in particular, after the first coagulation dehydration process is applied, the suspended matter is significantly reduced.

TABLE 1

Organic Desorption After the first dehydration After the second flocculation dewatering BOD (mg / L) 55500.0 46400.0 32500.0 COD _cr (mg / L) 63900.0 42500.0 22500.0 SS (mg / L) 70500.0 38400.0 3120.0 T-N (mg / L) 7770.235 2619.322 1077.807 T-P (mg / L) 408.242 258.546 60.232

On the other hand, the preliminary solids separated by the preliminary dewatering means 231, the first solids separated by the primary dewatering means 232 and the second solids separated by the primary flocculation dehydration means 233 are digesters. It is supplied to the dry anaerobic digestion tank 240 via a supply unit 290, wherein the preliminary solids, the first solids and the second solids have a total solids (TS) concentration of 15% or more, that is, a water content of 85% or less. It is desirable to. The reason for controlling the total solids concentration of the preliminary solids, the first solids, and the second solids supplied to the dry anaerobic digestion tank 240 to 15% or more is to satisfy the operating characteristics of the dry anaerobic digestion tank 240, Specifically, when the total solid concentration is 15% or less, that is, when the moisture content of the solid is 85% or more, the sludge to which the subsequent dehydration process is applied is dried even though the anaerobic digestion process through the dry anaerobic digestion tank 240 is caused by the relatively large amount of water. This is because the process to be returned back to the anaerobic digestion tank 240. In other words, in the case of the organic waste recycling apparatus according to an embodiment of the present invention, as the total solid concentration of the solids supplied to the dry anaerobic digestion tank 240 is maintained at 15% or more, to the dry anaerobic digestion tank 240 The sludge internal conveying process may be omitted.

In addition, in supplying the preliminary solid, the first solid and the second solid to the dry anaerobic digestion tank 240 through the digester supply unit 290, the total solids supplied according to the stabilization step of the dry anaerobic digestion tank 240. It is desirable to adjust the amount of. Specifically, in the initial stage of operation of the dry anaerobic digestion tank 240, as the microorganisms in the dry anaerobic digestion tank 240 is not mature and the total solid concentration value is irregular, the total solids of the preliminary solid, the first solid, and the second solid are It is preferable to supply 25 to 35% to the dry anaerobic digester 240, and gradually increase the amount of solids supplied during the stabilization period of 6 to 7 months to ultimately reduce the total amount of the preliminary solids, the first solids and the second solids. Supply to dry anaerobic digester (240). At this time, the remaining solids which are not supplied to the dry anaerobic digestion tank 240 during the stabilization period of the dry anaerobic digestion tank 240 are supplied to the sludge mixer 272 which will be described later to undergo a predetermined composting process. This will be described later in detail.

On the other hand, in order to improve the stirring characteristics of the solid in the anaerobic digestion tank 240, the digestion sludge discharged from the dry anaerobic digestion tank 240 may be re-introduced into the digester supply unit 290 without dehydration. At this time, the amount of the digested sludge re-introduced into the digester supply unit 290 is preferably about 1/3 of the total. Here, since the re-injected digested sludge is re-introduced into the digester supply unit 290 in a non-dehydrated state, its purpose is different from that of returning the digested sludge to the anaerobic digester in order to improve the conventional solid concentration.

Next, the dry anaerobic digester 240 receives the preliminary solids, the first solids, and the second solids from the preliminary dehydration means 231, the primary dehydration means 232, and the primary coagulation dehydration means 233, respectively. Dry anaerobic digestion of the preliminary solid, the first solid and the second solid. At this time, since there is no conveying sludge supplied to the dry anaerobic digester 240 in addition to the preliminary solid, the first solid, and the second solid, the size of the anaerobic digester can be significantly reduced in comparison with the prior art.

In addition, a secondary dehydration means 261 and a secondary coagulation dehydration means 262 are provided at the rear end of the dry anaerobic digestion tank 240. The secondary dewatering means 261 serves to dehydrate the digested sludge discharged from the dry anaerobic digestion tank 240, the secondary flocculation dehydration means 262 is the desorption liquid discharged from the secondary dehydration means 261 It acts as a coagulation and dehydration for. At this time, the secondary dehydration means 261 and the secondary coagulation dehydration means 262, like the preliminary dehydration means 231, primary dehydration means 232 and primary coagulation dehydration means 233, such as a centrifuge It may be implemented as, the secondary flocculation dehydration means 262 may be further provided with a flocculant administration means for administering a flocculant. The digested sludge separated by the secondary dehydration means 261 and the secondary flocculation dehydration means 262 is supplied to the composting means, and the separated dehydration liquid is supplied to the wastewater treatment apparatus. Here, in the case of the second dehydration liquid discharged through the secondary flocculation dehydration means 262, the water content is more than 97%, BOD is less than 9000mg / L, COD _cr is less than 2000mg / L, TN is less than 3000mg / L, TP It is preferable to control so that it may be 100 mg / L or less. On the other hand, in the flocculation dehydration through the secondary flocculation dehydration means 262, the amount of flocculant administered to the flocculation dehydration can be significantly reduced as the stripping solution undergoes a dry anaerobic digestion process.

On the other hand, biogas such as methane is generated by the anaerobic digestion by the dry anaerobic digestion tank 240, such biogas is collected through a separate biogas collecting means 250 and used for cogeneration. For reference, in the case of using an organic waste recycling apparatus according to an embodiment of the present invention, it was confirmed that biogas of 100 to 140 m ³ is produced per ton of solids.

Next, the composting means is digested sludge discharged from the secondary dehydration means 261 and the secondary flocculation dehydration means 262 via the dry anaerobic digestion tank 240 and the preliminary solids from the digester supply unit 290 The first and second solids are supplied to ferment the sludge and finally compost. The composting means is a combination of the sludge mixer 272, the moisture control agent 271 and the composting tank 273. Is done.

The sludge mixer 272, 152 is the digester supply unit 290 in the initial operation stage of the digested sludge and dry anaerobic digester 240 discharged from the secondary dewatering means 261, secondary flocculation dehydration means 262 It receives the preliminary solids, the first solids, and the second solids supplied from the water, and serves to properly mix the water regulator, for example, sawdust, supplied from the water regulator supply means 271, and through the process described above. The mixed mixture is fed to the aerobic composting tank 273 where the fermentation process takes place for about 36 days and finally converted to a good organic compost.

Lastly, the wastewater treatment apparatus is specifically composed of a wastewater pretreatment apparatus 281 and a plasma wastewater treatment apparatus 282. The wastewater pretreatment apparatus 281 serves to highly process the second dehydration liquid supplied from the primary flocculation and dehydration means 233 through a biological method, for example, an upflow anaerobic wastewater treatment apparatus may be used. The plasma wastewater treatment device 282 receives the wastewater discharged from the wastewater pretreatment device 281, the dehydration liquid discharged from the secondary flocculation dewatering means 262, and the leachate discharged from the composting tank 273. It plays a role. Here, a predetermined anaerobic digester is provided on one side of the wastewater pretreatment apparatus 281 to extract biogas by applying an anaerobic digestion process to the sludge discharged from the wastewater pretreatment apparatus 281.

On the other hand, the plasma wastewater treatment device 282, specifically, as shown in Figure 3, the reactor 310 to provide a space for wastewater treatment, the quartz tube 320 provided in the reactor 310, the quartz A coil 330 is provided around the tube 320 to generate a plasma according to power application, and a power supply unit 340 to apply power to the coil 330.

Under such a configuration, when power is applied from the power supply unit 340 to the coil 330 in a state in which wastewater and dehydration liquid are supplied into the reactor 310, plasma is generated around the quartz tube 320. As a result, radicals such as OH, OH ₂ and e _aq ^- and active molecules such as O ₃ and H ₂ O ₂ are generated. Reacts to remove contaminants in the wastewater.

_{^{NH 4 + + e aq - →}} NH 4

NH ₄ + OH → N ₂ ↑ + H ₂ O

NH ₄ + O → N ₂ ↑ + H ₂ O

Finally, the discharged water discharged through the plasma wastewater treatment device 282 is 700 mg / L or less, COD _cr is 1000 mg / L or less, TN is 500 mg / L or less, and TP is about 10 mg / L or less.

1 is a block diagram of an organic waste recycling apparatus according to the prior art.

2 is a block diagram of an apparatus for recycling organic waste according to an embodiment of the present invention.

Figure 3 is a block diagram of a plasma wastewater treatment apparatus according to an embodiment of the present invention.

Description of the main parts of the drawing

210: organic waste supply means 220: shredding sorting means

231: preliminary dewatering means 232: primary dewatering means

233: primary flocculation dewatering means 240: dry anaerobic digestion tank

250: biogas collection means 261: secondary dewatering means

262: secondary flocculation dehydration means 271: moisture regulator supply means

272: sludge mixer 273: compost tank

281: wastewater pretreatment apparatus 282: plasma wastewater treatment apparatus

290: digester supply unit

310 reactor 320 quartz tube

330: coil 340: power supply

Claims (11)

Shredding sorting means for shredding organic waste; Dewatering means for separating the crushed organic waste into an organic desorption solution and a solid; Dry anaerobic digestion tank for dry anaerobic digestion of solids discharged from the dehydration means; Composting means for fermenting digested sludge discharged from the dry anaerobic digestion tank to compost; And Composed of a combination of the dewatering means and wastewater treatment apparatus for the advanced treatment of the dewatering liquid and wastewater discharged from the dry anaerobic digestion tank, The dewatering means, Preliminary dehydration means for separating organic waste into organic waste and preliminary solids; primary dehydration means for separating the organic desorption liquid into a first dehydration liquid and a first solid; It consists of a primary coagulation dehydration means for separating the liquid and the second solid, The dry anaerobic digester, Analytical digestion of the first solid and the second solid by receiving the first solid and the second solid with a total solid concentration of 15% or more, The wastewater treatment device, A wastewater pretreatment device and a plasma wastewater treatment device, for treating the second dehydration liquid discharged by the primary coagulation dewatering means and the wastewater discharged from the dry anaerobic digestion tank, The wastewater pretreatment device is an organic waste material recycling apparatus, characterized in that consisting of an upflow anaerobic wastewater treatment device. delete According to claim 1, The plasma wastewater treatment apparatus, A reactor providing space for wastewater treatment, A quartz tube provided in the reactor, A coil provided around the quartz tube to generate a plasma upon application of power; And a power supply unit for applying power to the coil. delete The method of claim 1, further comprising a secondary dewatering means and a secondary flocculation dehydration means at the rear end of the dry anaerobic digestion tank, The secondary dewatering means serves to dehydrate the digested sludge discharged from the dry anaerobic digestion tank, the secondary flocculation dewatering means is characterized in that the role of coagulation dehydration for the digested sludge dehydrated by the secondary dewatering means Recycling device of organic waste. The organic waste recycling apparatus of claim 1, further comprising a biogas collection unit configured to collect biogas generated from the dry anaerobic digestion tank at one side of the dry anaerobic digestion tank. The method of claim 5, wherein the composting means is composed of a sludge mixer, a moisture control supply means and a composting tank, The sludge mixer serves to mix the digestion sludge supplied from the secondary dehydration means and the secondary flocculation dehydration means and the moisture control agent supplied from the moisture control agent supply means, and the composting tank mixes the mixture of the digestion sludge and the moisture control agent. A device for recycling organic waste, characterized in that it serves to ferment. The method of claim 1, wherein a digester supply unit for collecting the preliminary solids, the first solids and the second solids is further provided at the front end of the dry anaerobic digester, and one third of the total amount of the digested sludge discharged from the dry anaerobic digester is Recycling of the organic waste, characterized in that the input to the digester supply unit. delete delete delete

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