KR101346535B1 - A method for pretreatment of organic wastes and a device for pretreatment of organic wastes - Google Patents

Abstract

The present invention relates to an organic waste pretreatment method and apparatus, comprising the steps of: (a) passing organic waste through an orifice or venturi tube having a cross-sectional area smaller than the inlet at a pressure of 25 to 1999 psi; And (b) injecting ozone into the organic waste before, after, or simultaneously with (a) the organic waste pretreatment method, a chemical tank for supplying the chemical to the organic waste, and the organic solvent using a pump. Cavitation treatment tank for supplying the waste at a pressure of 25 ~ 1999 psi, Cavitation unit and ozone for passing the organic waste supplied from the cavitation treatment tank through orifice or venturi tube provided therein and resupply to the cavitation treatment tank Ozone reactor to ozone the organic waste using It is possible to provide an organic waste pre-treatment device is configured to include effectively pre-processing the organic waste.

Description

A method for pretreatment of organic wastes and a device for pretreatment of organic wastes}

The present invention relates to an organic waste pretreatment method and apparatus, and more particularly, to an organic waste pretreatment method and apparatus capable of effectively pretreating organic waste having a large particle size using a low pressure of 25 to 1999 psi.

In general, organic wastes are wastes generated by human consumption, and most of them are food waste, serving and livestock manure, and waste sludge or excessive sludge. Until now, these organic wastes have been treated by various methods such as landfilling, incineration, dumping, composting, auxiliary fueling, carbonization, etc., but a large amount of organic wastes are dumped or landfilled around the world. In Korea, the daily amount of food waste in 2005 was 12,977 tons, accounting for 38.5% of the total household waste, which caused various problems in the collection, transportation and disposal process due to its high water content and perishability.

In 2005, the direct ban on food waste was banned, which led to a sharp increase in the share of recycling. However, no clear alternative is available. For example, about 85% of livestock manure is recycled to organic fertilizer resources, and the remaining 15% is treated by purification or discharged to the ocean. Sewage sludge is banned from landfilling in 2003. More than 70% are disposed of by dumping at sea. However, by joining the London Convention, an international environmental convention, such water dumping will be banned from 2012 for sewage sludge and livestock manure, and 2013 for food waste wastewater. Therefore, in the future, these organic wastes can only be disposed of in an appropriate manner on land.

Against this background, methods for reducing the amount of organic waste generated by itself, recycling with compost or cover material or auxiliary fuel, and recovering energy sources such as methane (CH ₄ ) through anaerobic digestion, etc. Is emerging as a solution. Therefore, in recent years, the attention of the related industry has been focused on methods for properly pretreating organic wastes to implement the above-described methods. However, since most of the pretreatment technologies are insufficient in terms of efficiency and cost, the problems and solutions will be described in detail.

First of all, in order to reduce or reuse organic waste at source, it is necessary to refine the waste or to break up the floc structure of sewage sludge, and also to break cell walls so that the components of microorganisms are released to the outside, so that alternative technologies must be able to implement them.

In addition, in the case of treating organic waste through anaerobic digestion, the higher the anaerobic digestion efficiency, the more the solids are converted into biogas, resulting in the recovery of a large amount of energy source and, consequently, the waste to be disposed of eventually. The amount of decreases. Therefore, there is a need for a pretreatment technique capable of improving the digestion efficiency. For this purpose, it is necessary to reduce the amount of organic matter present as a solid and to increase the amount of dissolved organic matter.

In this regard, Patent No. 10-0948494 (name of the invention: sewage sludge pretreatment method, hereinafter referred to as "Prior Art 1") and patent application No. 10-2010-0011121 (name of the invention) filed by the inventor : Sewage sludge pretreatment device, hereinafter referred to as “Prior Art 2”) sewage sludge pretreatment that can reduce sludge by solubilizing sewage sludge using hydraulic cavitation and ozone, and improve sludge dewatering capacity and digestion efficiency. A method and apparatus thereof are disclosed.

However, according to the prior art 1 and the prior art 2, the livestock manure, because the cross section of the orifice must be small to form a pressure of 2000 ~ 8000 psi, and a screen device that can remove foreign matter and contaminants for smooth process operation There was a problem that only pretreatment limited to sewage sludge with smaller particles than treatment of relatively large particle size such as food.

Thus, the present inventors have come to the present invention after seeking ways to maximize the applicability and to exhibit the same or more effects in order to reduce waste and improve anaerobic digestion efficiency regardless of the type of organic waste.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and by effectively integrating 25 ~ 1999 psi hydraulic cavitation and ozone oxidation technology through an orifice or venturi tube having a large cross-sectional area, pretreatment of organic waste reduces weight loss, dehydration efficiency and digestion. It is an object of the present invention to provide a method and apparatus for pretreatment of organic waste that can comprehensively realize an improvement in efficiency.

As means for solving the above-mentioned technical problem,

The present invention relates to a method for pretreatment of organic waste, comprising the steps of (a) passing the organic waste through an orifice or venturi tube having a cross-sectional area smaller than the inlet at a pressure of 25-1999 psi and (b) It provides an organic waste pretreatment method comprising the step of injecting ozone into the organic waste before, after or at the same time.

In this case, hydrogen peroxide (H ₂ O _2), hydrogen peroxide sulfate (S ₂ O ₈ ^-) in the organic waste, permanganate (MnO ₄ ^-), sodium hypochlorite (NaOCl) any one or more of an oxidizing agent or sodium hydroxide is selected from ( NaOH) may be further included.

In addition, the present invention is a method for pretreatment of organic waste, comprising the steps of (a) passing the organic waste through an orifice or venturi tube having a cross-sectional area smaller than the inlet at a pressure of 25-1999 psi and (b) the (a) hydrogen peroxide (H ₂ O ₂₎ to said organic waste before or after the step, peroxide sulfate (S ₂ O ₈ ^-), permanganate (MnO ₄ ^-), hypochlorite any one or more oxidizing agents or are selected from sodium (NaOCl) It provides an organic waste pretreatment method comprising the step of injecting sodium hydroxide (NaOH).

In this case, the present invention may further comprise the step of ultrasonicating the organic waste.

On the other hand, the present invention, a chemical tank for supplying chemicals to the organic waste, a cavitation treatment tank for supplying the organic waste at a pressure of 25 ~ 1999 psi using a pump, and the organic waste supplied from the cavitation treatment tank inside Provided is an organic waste pretreatment apparatus comprising an cavitation unit for passing through an orifice or venturi tube provided in the recirculation chamber and an ozone reactor for ozone treatment of the organic waste using ozone.

The present invention also provides a storage tank for accommodating organic waste, a pump communicating with the storage tank and supplying the organic waste at a pressure of 25 to 1999 psi, a venturi inlet pipe connected to the pump, and the venturi inlet pipe. One end is connected to, the other end is configured to include a venturi discharge pipe is installed in communication with the storage tank, an ozone transport pipe inserted between the venturi discharge pipe and the venturi inlet pipe and an ozone generator coupled to the ozone transport pipe. Provided is an organic waste pretreatment device.

In this case, it is preferable that a partition is provided inside the storage tank.

In addition, the inside of the venturi inlet pipe and the venturi discharge pipe inside the tube communicating with the ozone transport pipe is preferably introduced.

In this case, the organic waste pretreatment apparatus may further include an ultrasonic treatment apparatus for ultrasonicating the organic waste.

According to the present invention, it is possible to pretreat not only organic wastes with small particles such as sewage sludge but also organic wastes with large particles such as livestock manure and food, and have effects similar or higher than those obtained by high pressure hydraulic cavitation and ozonation. You can get it.

In addition, the process combining the hydraulic cavitation and ozone oxidation can achieve better waste reduction, dehydration efficiency and anaerobic digestion efficiency than the hydraulic cavitation treatment or ozone oxidation treatment alone.

1 is a block diagram showing an organic waste pretreatment apparatus according to a preferred embodiment of the present invention,
Figure 2 is a block diagram showing an organic waste pretreatment apparatus according to another preferred embodiment of the present invention,
3 is an enlarged view illustrating a coupling structure of a venturi tube and an ozone transport tube of an organic waste pretreatment apparatus according to a preferred embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly explain the present invention, parts not related to the description are omitted, and similar parts are denoted by similar reference numerals throughout the specification.

First, the present invention is divided into a method for pretreatment of organic waste and a device for pretreatment of organic waste.

The method for pretreatment of organic wastes according to the present invention comprises a combination of hydrodynamic cavitation treatment of organic wastes, ozone treatment of organic wastes and chemical treatment of organic wastes with an oxidizing agent. do.

Specifically, the step of hydraulic cavitation treatment of the organic waste is to pass the organic waste through an orifice or venturi tube having a smaller cross-sectional area than the inlet in order to refine the organic waste and dismantle the flock structure.

In this case, the present invention is characterized in that the organic waste cavitation treatment at a low pressure of 25 ~ 1999 psi rather than a high pressure of 2000 psi or more. In this configuration, an orifice or a venturi tube having a relatively large cross-sectional area can be used than a high pressure treatment, and as a result, small particles of sewage sludge and organic waste such as livestock manure and food with large particles can be effectively treated. Can be.

Subsequently, the step of ozone treating the organic waste may be carried out before, after or simultaneously with the above-mentioned cavitation treatment step as a process for oxidizing the organic waste to realize sludge reduction, dehydration efficiency, improvement of digestion efficiency, and the like.

In addition, the step of chemically treating the organic waste with an oxidizing agent may be performed before or after the above-described cavitation treatment step as a process for oxidizing the organic waste to maximize the pretreatment efficiency as in the ozone treatment step.

In this case, as the drug is hydrogen peroxide _{(H 2 O 2, hydrogen peroxide} ), hydrogen peroxide sulfate ^{_{(S 2 O 8 -, persulfate}} ), permanganate (MnO ₄ ^-, permagnate), sodium hypochlorite (NaOCl, sodium hypochlorite), etc. Any one or more oxidizing agents or sodium hydroxide (NaOH, sodium hydroxide) selected from may be used.

On the other hand, in the present invention, it is also possible to integrate all the three processes described above, if necessary, is not particularly limited, may be added to the step of ultrasonic treatment of organic waste to further improve the efficiency of pretreatment.

As described above, the combination of the cavitation treatment process and the oxidation treatment process is preferable because excellent synergy effect can be obtained for the pretreatment of the organic waste.

The organic waste pretreatment method according to the present invention has been described above. Hereinafter, an organic waste pretreatment apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing an organic waste pretreatment apparatus according to a preferred embodiment of the present invention.

As shown in FIG. 1, the organic waste pretreatment apparatus 100 according to the preferred embodiment of the present invention includes a chemical tank 110, a cavitation treatment tank 120, a cavitation unit 122, and an ozone reaction tank 130. It is configured to include.

First, the chemical tank 110 is configured to supply an oxidant or sodium hydroxide (NaOH) to the organic waste, the organic waste in the chemical mixing unit 112 after injecting the chemical into the organic waste using the pump 111 It is mixed with enough. In this case, as the oxidizing agent, hydrogen peroxide (H ₂ O ₂ ), peroxide sulfate (S ₂ O ₈ ⁻ ), permanganate (MnO ₄ ⁻ ), sodium hypochlorite (NaOCl), or the like may be used.

Next, the cavitation treatment tank 120 is a configuration for supplying the organic waste mixed with the drug in the drug mixing unit 112 to the cavitation unit 121, 25 ~ 1999 psi using the pump 121 Transport organic waste at pressure. To this end, a compression device for directly compressing and discharging the organic waste, a high pressure fluid generator or a high pressure fluid supply device for transferring the organic waste to a high pressure through a high pressure fluid may be provided separately, in addition to the transport of organic waste Various means may be provided.

Subsequently, the cavitation unit 122 is configured for cavitation of the organic waste supplied from the cavitation treatment tank 120, and an orifice through which organic waste passes through the cavitation unit 122 for such cavitation treatment Or a venturi tube.

In this case, the cavitation unit 122 is installed between the pump 121 and the cavitation processing tank 120, so that the organic waste is cavitation processing tank 120, the pump 121 and the cavitation unit Repetitive circulation of 122 can result in the miniaturization of organic waste and the dissolution of flocs.

Finally, the ozone reaction tank 130 is configured to react the organic waste treated in the cavitation unit 122 with ozone, and gaseous liquid by the gas-liquid contact pump 132 to generate ozone from the ozone generator 131. After the transfer to the mixing unit 133 and mixed with the organic waste it is reacted. In this case, the ozone generator 131 is provided with an oxygen generator 134 for supplying oxygen to form ozone, and in the ozone reactor 130, bubbles are generated due to the reactivity of organic waste and ozone to remove them. Defoamer 135 is preferably installed.

As described above, the organic waste treated by ozone is then transferred to an anaerobic digester or a dehydration apparatus for subsequent treatment.

The organic waste pretreatment apparatus according to the preferred embodiment of the present invention has been described above. In this regard, the chemical tank 110, the cavitation treatment tank 120 and the ozone reaction tank 130 is described as an example in this case, but the installation of each of the above configuration in the present invention is limited to the above Of course, it can be arranged by appropriately adding or subtracting or modifying as necessary. For example, only one of the chemical tank 110 and the ozone reaction tank 130 may be installed or installed in the opposite direction. Also, although not shown in the drawing, an ultrasonic treatment device may be additionally installed to maximize the pretreatment effect of the organic waste. It is also possible.

Figure 2 is a block diagram showing an organic waste pretreatment apparatus according to another preferred embodiment of the present invention, Figure 3 is an enlarged coupling structure of the venturi tube and ozone transfer pipe of the organic waste pretreatment apparatus according to a preferred embodiment of the present invention Figure is shown.

2 and 3, the organic waste pretreatment apparatus 200 according to another preferred embodiment of the present invention includes a storage tank 210, a pump 220, a venturi inlet pipe 221, and a venturi discharge pipe. 222, the ozone transport pipe 230 and the ozone generator 231 is configured.

First, the storage tank 210 is configured to receive the supplied organic waste and discharge after cavitation and ozone treatment, for this purpose, the inlet pipe 211 and the pump 212 at the front end, the discharge pipe 214 at the rear end, respectively Is formed. In this case, the supply amount of the organic waste is made by a valve 213 installed between the pump 212 and the storage tank 210.

On the other hand, it is preferable that the partition wall is installed in the middle of the inside of the storage tank (210). This is because, as described above, when the partition wall is provided, air and bubbles rise, and only organic waste descends, thereby increasing treatment efficiency. In this case, the bubbles gathered to the top of the storage tank 210 is removed by the bubble remover 240.

Next, the pump 220 is configured to supply the organic waste to the venturi inlet pipe 221 at a pressure of 25 ~ 1999 psi, is installed in communication with the lower portion of the storage tank (210). In this case, the supply amount of the organic waste is controlled by the valve 223.

Subsequently, the venturi inlet pipe 221 is configured for hydraulically cavitation treatment of the organic waste supplied from the pump 220, and is connected to the pump 220. In this case, the pressure generated by the pump 220 is measured by a pressure gauge 224 installed at the rear end of the pump 220.

Next, the venturi discharge pipe 222 is configured to hydraulically cavitation the organic waste together with the venturi inlet pipe 221, a front end is connected to the venturi inlet pipe 221, the other end is the storage tank Communicating installation 210 is provided. In this case, the other end of the venturi discharge pipe 222 is provided with a valve 225 for controlling the discharge of the organic waste, and a pressure gauge 227 for measuring the discharge pressure of the organic waste.

Subsequently, the ozone transport pipe 230 is configured to inject ozone into the organic waste and oxidize simultaneously with the cavitation treatment, and is inserted between the venturi inlet pipe 221 and the venturi discharge pipe 222. In this case, the connection portion of the venturi inlet pipe 221 and the venturi discharge pipe 222 has a tapered shape in which the cross-section is gradually narrowed, the inside of the venturi inlet pipe 221 and the venturi discharge pipe 222 is An inner tube 226 communicating with the ozone transport tube 230 is introduced.

When the organic waste is configured as described above, the pressure and speed increase in the process of passing the organic waste through the venturi inlet pipe 221, thereby generating a vacuum phenomenon and mixing with ozone supplied through the inner pipe 226. Dissolution causes hydraulic cavitation. Subsequently, in the process of passing the organic waste through the venturi discharge pipe 222, a strong flow rate is changed to a pressure. As a result, the mixed ozone is pressurized and dissolved to cause the ozone oxidation reaction. On the other hand, the pre-treated organic waste is finally transferred to the anaerobic digestion tank or dehydration apparatus through the discharge pipe 214 is subjected to a subsequent treatment process.

Finally, the ozone generator 231 is coupled to the ozone transport pipe 230 in a configuration for supplying ozone to the ozone transport pipe 230.

As described above, in the case of the present embodiment, a hydraulic cavitation process and an oxidation process by ozone are performed at the same time as in the above-described embodiment. Such a configuration can shorten the process and save time, and exhibits excellent effects in terms of pretreatment efficiency.

In this case, the valves 213, 223, 225 are respectively adjusted so that the amount supplied to the venturi inlet pipe 221 is large in preparation for the amount of organic waste flowing into the storage tank 210. Waste is repeatedly cavitation and ozonated to maximize efficiency.

Hereinafter, embodiments of the present invention as described above will be described.

Example

First, the organic waste pretreatment apparatus 100 was manufactured in a small size, and then experiments were performed on the change of properties of the organic waste by cavitation and ozone oxidation. Specifically, the cavitation treatment tank 120 and the ozone reaction tank 130 was designed to about 20 liters, and installed a sampling port at the rear end of each treatment device to collect the sample after the treatment. In addition, the sample used sewage sludge, which is a representative organic waste, and the sewage sludge used a bioreactor (MBR) pilot plant (a treatment capacity of 20 tons / day, and an average MLSS of 9,000 mg / L).

Meanwhile, in the case of cavitation treatment, the sludge of the cavitation treatment tank 120 has a constant residence time, and the treatment is repeated several times. In the case of ozone treatment, the ozone generation amount of the ozone generator 131 is calculated by calculating the amount of ozone injection. Injected by changing the ozone concentration, it was to stay in the ozone reaction tank 130 for a certain time.

In addition, the experimental conditions of each treatment device was set to 24 times the cavitation circulation when the cavitation pressure 290 psi, 12 times the cavitation circulation when the cavitation pressure 725 psi. In the case of ozone treatment, the ozone injection amount was set at 100 mg / L and injected constantly.

Table 1 below shows the results of comparing sludge solubilization with soluble COD (SCOD; Soluble Chemical Oxygen Demand) and sludge reduction with SS (Suspended Solids).

division enemy Cavitation
Sole process Cavitation + Ozone
Integrated process Cavitation pressure 0psi 290 psi 725 psi 290 psi 725 psi Cavitation Cycles 0 times 24 times 12th 24 times 12th SCODcr (mg / L) 29.15 239.62 245.84 865.24 898.46 SCODcr growth (%) - 722.0 743.4 2868.2 2982.2 SS (mg / L) 9826 9248 9196 6328 6264 SS Reduction (%) - 5.9 6.4 35.6 36.3

From Table 1, in the case of the hydraulic cavitation alone process, the sludge SCOD value increases according to the change in the cavitation pressure and the number of cavitation cycles, so that the sludge can be solubilized, but the reduction effect of the sludge is small. You can check it. However, according to the integrated process of hydraulic cavitation and ozone oxidation as in the present invention, the SCOD is significantly increased and the SS is markedly reduced to realize solubilization and reduction of sludge. On the other hand, in the ozone oxidation alone process, the energy input per solubilization sludge was higher than the hydraulic cavitation and ozone oxidation integration process, which was inefficient. This synergy effect for sludge solubilization can be achieved very effectively by optimizing the integrated process conditions of hydraulic cavitation and ozone oxidation to the target organic matter.

The preferred embodiments of the present invention have been described in detail with reference to the drawings. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.

Therefore, the scope of the present invention is defined by the appended claims rather than the foregoing detailed description, and all changes or modifications derived from the meaning, range, and equivalence of the claims are included in the scope of the present invention. .

100: organic waste pretreatment device
110: chemical tank 111: pump
112: chemical mixing unit 120: cavitation treatment tank
121: pump 122: cavitation unit
130: ozone reactor 131: ozone generator
132: gas-liquid contact pump 133: gas-liquid mixing unit
134: oxygen generator 135: bubble remover
200: organic waste pretreatment device
210: storage tank 211: inlet pipe
212: pump 213: valve
214: discharge pipe 215: valve
220: pump 221: venturi inlet pipe
222: venturi discharge pipe 223: valve
224 pressure gauge 225 valve
226: inner tube 227: pressure gauge
230: ozone transport pipe 231: ozone generator
240: bubble remover

Claims (9)

In the method of pretreating organic waste,
(a) passing the organic waste through an orifice or venturi tube having a cross-sectional area smaller than the inlet at a pressure of 25-1999 psi;
(b) injecting ozone into the organic waste before, after, or simultaneously with step (a); And
(c) sonicating the organic waste;
Organic waste pretreatment method comprising a. The method of claim 1,
Hydrogen peroxide (H ₂ O ₂₎ in the organic waste, peroxide sulfate (S ₂ O ₈ ^{-) -} a, sodium hypochlorite (NaOCl) any one or more of an oxidizing agent or sodium hydroxide (NaOH) is selected from, permanganate (MnO ₄₎ Organic waste pretreatment method further comprising the step of injecting. In the method of pretreating organic waste,
(a) passing the organic waste through an orifice or venturi tube having a cross-sectional area smaller than the inlet at a pressure of 25-1999 psi;
Among them, sodium hypochlorite (NaOCl) (b) wherein (a) hydrogen peroxide (H ₂ O ₂₎ to said organic waste before or after the step, peroxide sulfate ^{_{(S 2 O 8 - -)}} , permanganate (MnO ₄₎ Injecting any one or more oxidants or sodium hydroxide (NaOH) selected; And
(c) sonicating the organic waste;
Organic waste pretreatment method comprising a. delete A chemical tank for supplying chemicals to organic wastes;
Cavitation treatment tank for supplying the organic waste at a pressure of 25 ~ 1999 psi using a pump;
A cavitation unit passing the organic waste supplied from the cavitation treatment tank through an orifice or venturi tube provided therein and then resupplying the organic waste to the cavitation treatment tank; And
An ozone reactor for ozonating the organic waste using ozone;
Organic waste pretreatment device comprising a. A storage tank containing organic waste;
A pump communicating with the storage tank and supplying the organic waste at a pressure of 25 to 1999 psi;
A venturi inlet pipe connected to the pump;
A venturi discharge pipe having one end connected to the venturi inlet pipe and the other end communicating with the storage tank;
An ozone transport pipe inserted between the venturi discharge pipe and the venturi inlet pipe; And
An ozone generator coupled to the ozone transport tube;
Organic waste pretreatment device comprising a. The method according to claim 6,
The organic waste pretreatment apparatus, characterized in that the partition is installed inside the storage tank. The method according to claim 6,
The inside of the venturi inlet pipe and the venturi discharge pipe organic waste pre-treatment device, characterized in that the inner tube is in communication with the inlet pipe. 9. The method according to any one of claims 5 to 8,
The organic waste pretreatment apparatus further comprises an ultrasonic treatment apparatus for ultrasonicating the organic waste.

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