KR20150114153A - Treatment System of Food Waste Leachate Capable of Deodoring - Google Patents

Abstract

The present invention provides a food waste desorption leachate treating system capable of performing deodorization. The food waste desorption leachate treating system comprises: a heat solubilizing device for solubilizing sludge by applying heat to a food waste desorption leachate; a boiler for supplying heat needed for the heat solubilizing device; a heat exchanger for cooling treated water discharged from the heat solubilizing device; a pressure floating tank for floating and removing a coagulated material including oil of the treated water heat-solubilized in the heat solubilizing device; an anaerobic digestion tank for methane-fermenting the treated water discharged from the pressure floating tank; a dehumidifier for removing moisture from gas discharged from the anaerobic digestion tank; and a deodorizing device having activated carbon for deodorizing the gas from which moisture is removed by the dehumidifier.

Description

TECHNICAL FIELD The present invention relates to a treatment system for food waste leachate capable of deodorization,

More particularly, the present invention relates to a system for efficiently removing oil and solids in a food waste desorption filtrate, minimizing the amount of sludge generated while reducing the amount of chemical inputs, and operating costs and energy consumption The present invention relates to a food waste disposal filtrate treatment system capable of deodorizing treatment that can reduce the energy pollution problem during the winter season and reduce the secondary environmental pollution problem.

The desorption filtrate discharged from the food waste dehydration process is composed of water, suspended solid and oil. Since the oil is stably present in the water phase in an emulsion state and the suspended solid is dispersed as fine particles, it is difficult to separate the oil and the suspended solid from the desolvation solution by a conventional method.

To date, various methods for treating food waste have been known as follows.

First, it can be landfilled directly in the ground, but it is prohibited as a problem of odor and groundwater pollution.

Secondly, it can be sterilized by high temperature to be used as feed for animals. However, this method has bad odor, low nutritional value as feed, low demand, low fuel cost and high condensation water treatment efficiency in the metropolitan area.

Third, food waste is composted by mixing it with a sub-homogenizer. This method is not only notable in that the odor is not only bad but also it is difficult to compost due to salinity and oil content. Also, due to problems such as salinity scale of farmland, .

Fourth, solid-liquid separation is performed and the dehydrated sludge is incinerated and the desorption filtrate is introduced into the sewage treatment plant. This treatment method should also solve the odor problem, it should have an extension of the incinerator and the sewage treatment plant, re-examine the total phosphorus (TP) and total nitrogen (TN) treatment method of the sewage treatment plant, do.

Next, solid-liquid separation is performed, and the dehydrated sludge is composted, and the desalination filtrate is treated separately. In the composting of dehydrated sludge, salinity and oil are mostly discharged into desalination filtrate, so it is possible to solve salinity scale and process compaction problem, and the amount of dehydrated sludge is reduced to 20 ~ 40%. Therefore, It can reduce security and bad complaints. It is also very economical because it recycles waste. However, in the treatment of tale filtrate, it was possible to dispose of it by ocean dumping, but the prohibition of marine dumping was confirmed and it is an urgent task to dispose of it.

The total amount of solid (TS) concentration of 80,000 to 150,000 mg / ℓ, the CODcr concentration of 100,000 to 250,000 mg / ℓ, the BOD concentration of 50,000 to 100,000 mg / ℓ, the total nitrogen TN concentration of 2,000 ~ 4,000 mg / ℓ, salinity concentration of 8,000 ~ 10,000 mg / ℓ, total phosphorus concentration of 600 ~ 800 mg / ℓ and oil concentration of 0.5 ~ 15,000 mg / ℓ . In addition, acid fermentation takes place during the collection process and the pH is very low as 3.0 ~ 4.0. This is because the concentration is 500 to 2000 times higher than that of sewage, and if the concentration is lowered in the pretreatment process and neutralization is not performed, the treatment cost and site area become larger and the treatment efficiency becomes lower.

In addition, since the food waste disposal filtrate contains a high concentration of solid matter, it must be separated and dehydrated, but it does not react well with chemicals, and there are many sludges that are generated by coagulation.

The sludge generated in such a large quantity can not be landfilled because of the contamination of groundwater, and it is composted or transferred to the incinerator for incineration. However, this sludge has a high salinity and water content and a high concentration of flora and fauna in the flora and fauna, causing many problems in composting and incineration, and there is a problem of continuously generating odor.

Therefore, it is urgently required to completely deodorize the sludge while reducing the amount of sludge generated in the process of removing the food waste from the aspect of economy and environmental protection.

SUMMARY OF THE INVENTION The present invention has been conceived to solve the problems of the prior art as described above. It is an object of the present invention to effectively remove oil and solids in a food waste rinse filtrate, minimize the amount of sludge generated while reducing the amount of chemical feed, And to provide a food waste disposal filtrate treatment system capable of deodorizing treatment that can reduce the energy pollution problem in the winter season and reduce the secondary environmental pollution problem.

The technical problem of the present invention as described above is achieved by the following means.

(1) a trough filtrate reservoir for collecting the filtrate of the food garbage tallies; A solid-liquid separator for solid-liquid separation of the desorption filtrate supplied from the desulfurization solution storage tank; A pulverizer for pulverizing particles having a predetermined size or larger in the solid-liquid separator and recycling the pulverized particles to a desalination / filtrate storage tank; A neutralizer for neutralizing the treated water separated in the solid-liquid separator; A heat dissolving device for solubilizing the sludge at a pH of the neutral region at a pressure of 18 to 22 kg / cm 2 and a temperature of 180 to 200 ° C by applying heat to the food waste desorption filtrate; A boiler for supplying heat required for the heat dissolving apparatus; A heat exchanger for cooling the treated water discharged from the thermal solubilizer; A pressurized floating tank in which air having a pressure of 3 to 5 kg / cm 2 is introduced into the heat-solubilization apparatus to float and remove flocculated matter containing oil in the treated water subjected to heat-solubilization treatment; An anaerobic digester for methane fermentation of the treated water discharged from the pressurized floating tank; A dehumidifier for removing moisture from the gas discharged from the anaerobic digester; And a deodorizer having activated carbon for deodorizing the dehumidified gas from the dehumidifier.

(2) In the above (1)

Further comprising a coagulation reaction tank for introducing an inorganic coagulant, caustic soda, and a polymer between the thermal solubilizer and the pressurized floating tank to coagulate the food waste.

According to the present invention as described above, it is possible to effectively remove oil and solids from the food waste separation filtrate, minimize the amount of sludge generated while reducing the amount of the drug, significantly reduce the operation cost and energy consumption, It reduces secondary environmental pollution problems and chronic odors.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a system for treating a food garbage tearing solution capable of deodorizing according to the present invention. FIG.
2 is a configuration diagram of a heat dissolving apparatus according to an embodiment of the present invention.
3 is a configuration diagram of a flocculation tank according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a deodorization processable food waste disposal filtrate processing system according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a configuration diagram of a system for treating a food garbage tearing solution capable of deodorizing according to the present invention.

1, the desorption filtrate processing system according to the present invention includes a desulfurization filtrate storage tank 10, a solid-liquid separator 20, a pulverizer 30, a neutralizer 40, a mixing device 50, a heat exchanger The deodorizing device 130 and the deodorizing device 130 are connected to each other by the heat exchanger 60, the thermal solubilizer 70, the boiler 80, the flocculation tank 90, the pressurized floating tank 100, the storage tank 110, the anaerobic digestion tank 120, 140).

The collected food waste is first separated into a solid fraction and a desorption filtrate, and then the desorption filtrate is transferred to the storage tank 10 and stored.

The desorption filtrate stored in the storage tank 10 is transferred to the solid-liquid separator 20 to separate solid components (fine contaminants) of a certain size, for example, φ = 1 mm or more.

The solid-liquid separator (20) is preferably constituted by an outer cylinder which prevents the filtration of the filtration of the cylindrical inner passage. A scraper for discharging the separated contaminants is provided in the inner cylinder, the inner cylinder is rotated at 200 rpm, the scraper is rotated at 220 rpm, and the contaminants are discharged by the rotation difference. The body of the inner tube is decorated with a perforated net of φ = 1 mm or less and a wedge wire of a gap of 1 mm or less.

The solid component separated in the solid-liquid separator 20 is sent to the crusher 30, pulverized to less than 1 mm, and then conveyed to the storage tank 10.

The crusher 30 is equipped with a propeller-shaped blade in the body for preventing scattering of the crushed contaminants. The number of rotations of the blade is adjusted to 1200 to 3600 rpm according to the kind of impurities.

The treated water separated from the solid-liquid separator 20 (hereinafter, the wastewater discharged through each of the constitution steps will be referred to as treated water) is usually treated with an acidic solution having a pH within the range of 3 to 5, To be neutralized.

The neutralizer 40 is equipped with a stirrer of 90 to 120 rpm in a reactor of a rectangular tube type, and a feed pump and a neutralizer reservoir for feeding the neutralizer are installed. Preferably, the pH of the treated water discharged from the neutralization unit 40 is adjusted to a range of 6 to 7, and the treatment efficiency of the desorbing effluent initially supplied within the above range is increased to 50%. To this end, a pH meter (not shown) for detecting and adjusting the amount of neutralizing agent may be installed in the neutralizer 40.

The treated water discharged from the neutralizer 40 flows into the mixing device 50 to induce complete mixing to increase the solubilization efficiency of the subsequent stage of the thermal solubilizer 70.

The mixing apparatus 50 is equipped with a stirrer of 90 to 120 rpm in a reactor in the form of a rectangular tube. In the present invention, the mixing device 50 may be omitted and the neutralization device 40 may be directly connected to the heat exchanger 60 as occasion demands.

The treated water discharged from the mixing device (50) flows into the heat exchanger (60). The heat exchanger (60) performs heat exchange in a non-contact manner between the high-temperature treated water discharged from the heat-solubilizing device (70) and the low-temperature treated water flowing into the heat exchanger.

In the heat exchanger 60, a flow meter and a pressure gauge are provided in the inflow portion of the treated water to control the flow rate and the pressure, and a pressure control pressure gauge and an automatic valve are installed in the discharge portion of the heat-exchanged cooled treated water .

The treated water preliminarily heated in the heat exchanger (60) flows into the heat dissolving apparatus (70), and even if a relatively small heat source is supplied from the boiler (80), the thermal hydrolysis reaction can be effectively performed.

 For this purpose, the boiler 80 is composed of a body, a burner, a circulating pump, a heating medium expansion tank, a heat-insulating automatic valve, a communication tube, a storage tank for supplying heat, and a control system. Preferably, the burner of the boiler 80 uses a combined burner that can use biogas and propane gas produced by the system of the present invention. The heating medium supply temperature is 200 to 250 DEG C, and the automatic valve is operated according to the temperature of the heat dissolving apparatus, and the supply pressure is preferably 1 to 3 kg / cm < 2 >.

The heat dissolving apparatus 70 includes an inner tube 71, an outer tube 72, and a swirling flow guide portion 73, as illustrated in Fig.

 The inner pipe 71 has a treated water inlet 71a at one end and a treated water outlet 71b at the other end. In the inner pipe 71, the treated water is introduced through the treated water inlet 71a, the treated water is thermally hydrolyzed and discharged to the outside through the treated water outlet 71b, and the treated water And serves as a reaction space.

 The outer tube 72 is formed with a charging port 72a through which the heating medium supplied from the boiler 80 is supplied to one end of the outer tube 72. The heating medium is introduced into the outer tube 72 through the heating medium discharging port 72b formed at one side of the other end, Is circulated through the boiler (80).

Herein, the outer tube 72 serves to heat the inner tube 71 by the heating medium introduced into the inner tube 71 to heat the treated water flowing into the inner tube 71, thereby promoting the flow of the treated water and promoting thermal hydrolysis of the treated water do.

The swirling flow guiding portion 73 includes a support 73a provided inside the inner pipe 71 and a swirling flow inducing vane 73b spirally formed on the outer circumferential surface of the support 73a, (73b) divides the inner space of the inner pipe (71) into a plurality of spaces, thereby causing the process water to swing. The swirl flow inducing vane 73b serves to guide the moving direction of the treatment water so that the treatment water flowing into the inner pipe 71 can be swiveled.

Due to the above structure, the efficiency of heat exchange between the treated water and the heating medium, that is, the heat transfer efficiency from the heating medium to the treated water, becomes very large, so that the stirring of the treated water can be smoothly performed without a separate stirring facility, It is possible to prevent precipitation or deposition of the catalyst and increase the reaction efficiency.

Preferably, the heat dissolving apparatus 70 performs the heat solubilization at a pressure of 18 to 22 kg / cm 2 and a temperature of 180 to 200 ° C. For this purpose, the temperature of the heating medium supplied from the boiler 80 is 200 to 250 ° C. It is good. Under the above-described conditions, solubilization of the solids can be completely performed even with a relatively small heat source, without additionally adding a reaction catalyst, an oxidizing agent, and the like into the thermal solubilizer 70.

To this end, the thermal solubilizer 70 may further include a sensor for sensing flow rate, temperature, and pressure, an automatic valve for controlling the pressure, and a control unit for controlling the valves.

The treated water discharged from the thermal solubilizer 70 is supplied to the flocculation tank 90 through the heat exchanger 60. The flocculation tank (90) is preferably equipped with a stirring means (not shown) and a pH meter (not shown) for sensing and adjusting the amount of flocculant to assist the flocculation reaction.

The flocculation tank (90) is used for flocculating various particles including oil, fine solid, and the like contained in the treatment water. The inorganic flocculant, caustic soda, and polymer are injected through the flocculant inlet as needed. At this time, the amount of the flocculant can be detected and adjusted using a pH meter (not shown).

In the present invention, the flocculation reaction tank 90 is preferably a pipe reactor type as shown in FIG. 3, and a pipe 90a such as a discharge port of a feed pump (not shown) at the front end is stacked in multiple stages, Space utilization can be increased.

At this time, the multi-stage pipes 90a are stacked and the upper and lower pipes are connected by an elbow 90b made up of both ends 90b ₁ and 90b ₂ of the upper and lower pipes. Then, the front end 91 is an inflow pump, And is connected to the floating tank (100). In this case, preferably, an inlet (not shown) is provided at the front part of the reactor so that the organic coagulant can be introduced. The length of the pipe reactor is preferably set so that the residence time is 25 to 60 seconds.

When a multi-stage pipe is used to implement the flocculation reaction tank 90, a separate stirrer is not required, so that facility and operation cost are reduced. In general, a neutralizer feed unit and an inorganic flocculant feed unit are required for the flocculation reaction. (90), a high solid-liquid separation efficiency can be exhibited in the pressurized floating tank (100) at the subsequent stage even without these devices due to the nature of the process.

In the present invention, in the flocculation reaction tank (90), the pressurized floating tank (100) is provided at the rear end of the flocculation tank (90) ).

The pressurized floating vessel 100 removes the remaining suspended solids, thereby eliminating the disturbing elements of the anaerobic digester 120 in the downstream stage and enhancing the digestion efficiency. The pressurized floating tank 100 is provided with a rectangular rectangular barrel and a scraper for removing scum from the upper portion thereof to discharge the suspended solids to the rear end of the pressurized floating tank. A pressurizing pump of a high pressure is installed in the lower part of the rear end of the pressurized floating tank 100 to continuously circulate the treated water to the front end through a pipe reactor type distributing device and a high pressure air 3 kg / ㎠ or more) is injected using a compressor or the like to increase the floatation efficiency. In the embodiment of the present invention, the linear speed of the scraper is 1 to 3 m / min, the pressure of the pressurizing pump is 3 to 5 kg / cm 2, the circulating rate of the pressurizing pump is 50 to 100% The area load is preferably 4 to 5 m 3 / m 2 · hr.

The treated water discharged from the pressurized floating tank 100 is stored in the storage tank 110 and is transferred to the anaerobic digestion tank 120 at the rear stage.

In the anaerobic digestion tank 120, organic substances present in the treated water are removed using methane fermentation. In the anaerobic digestion tank 120, methane fermentation bacteria are cultivated, and organic matter in the treated water is decomposed by these bacteria, and the generated methane gas is discharged to the outside.

The anaerobic digestion tank 120 has a square column-shaped barrel, an inflow and distribution unit is installed at the lower part, and a GSS unit for gas-liquid separation is installed at the upper part. At this time, the inflow water can be introduced using the lower distribution device, and the return pump can be installed to increase the activity of the anaerobic microorganism. The upper GSS unit installs square type gas-holder to prevent scattering of methane gas, and WAIR is installed to discharge treated water.

Preferably, the gas discharged from the anaerobic digestion tank 120 completely removes moisture through the dehumidifier 130, and the dehumidified gas is deodorized by the deodorizer 140 mounted on the column, Adsorbs and removes sulfur compounds and various volatile substances.

As described above, the moisture and odor-causing substances are removed and the remaining methane gas is stored in the gas storage tank 150 to self-procure the energy required in the process. The residual methane gas (about 50 to 60% Electricity is produced through the device 160, or utilized as a fuel gas.

The gas storage tank 150 stores the methane gas generated in the form of a dome, and allows the gas to be used according to the application purpose. The methane gas is temporarily stored in the gas storage tank 150 and then transferred to the compression storage furnace using the gas compressor to be used according to the intended use. At this time, a part of the gas may be used as the fuel for the heating medium boiler 80 of the thermal solubilizing apparatus, and the remaining surplus gas may be supplied to the gas company by installing a generator to produce electricity or installing a purifier. Preferably, the dome-shaped and compressed-storage tank is installed in a size of HRT = 6 to 8 hours, and the generator and the methane gas purifier are installed inside and outside with a capacity of 1 to 2 hr.

The treated water discharged from the anaerobic digestion tank 120 is treated by the post-treatment process of the subsequent process. In describing the apparatus of the present invention as described above, a pump can be installed as many times as necessary in a necessary portion for transferring treated water between respective apparatuses, and such a configuration is obvious to those skilled in the art, and a detailed description thereof will be omitted.

As described above, when the system according to the present invention is used, the heat exchange efficiency is maximized, and the fine solids (impurities) and sludge contained in the desorbing filtrate of the food waste are not immersed in the heat dissolving apparatus constituting the system, Not only efficiently removes oil and solids in the finally discharged treatment water but also allows the organic substances in the treated water to be completely removed by anaerobic fermentation.

Hereinafter, the present invention will be described in more detail with reference to the following examples and comparative examples. It is to be understood, however, that the same is by way of illustration and example only and is not to be taken by way of limitation.

[Example 1]

As a result of treating the food waste using the system shown in FIG. 1 (see the operating conditions in Tables 1 to 2 below), oil and solid matter in the final 20 ton of treated water discharged from the initial desolvation filtrate Filtrate), as well as organic matter in the treated water was completely removed by methane gas by anaerobic fermentation up to 80% (Table 3).

Heat exchanger operating conditions Inlet temperature
(° C) Discharge temperature
(° C) Inlet pressure
(kg / cm2) Outlet pressure
(kg / cm2) Residence time
(min) Tally filtrate 3 to 20 120 ~ 132 22 21 30 to 40 Heat-solubilized water 180 ~ 200 45 to 55 20 19 40 to 60

The pressure change is caused by the pressure loss due to the passage length.

Heat-Solubilization Apparatus Operating Conditions Inlet temperature
(° C) Discharge temperature
(° C) Inlet pressure
(kg / cm2) Outlet pressure
(kg / cm2) Residence time
(min) Heat-solubilizing device 120 ~ 132 180 ~ 200 21 20 90-120

Processing result Oil Solids Organic matter Initial desorption filtrate 100 100 100 Final processed number 0 20 15

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, 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 invention as defined by the appended claims. It can be understood that

10: Tally filtrate reservoir
20: Solid-liquid separator
30: Grinder
40: Neutralizer
50: mixing device
60: heat exchanger
70: Heat dissolving device
80: Boiler
90: flocculation tank
100: Pressurized floating tank
110: Storage tank
120: anaerobic digester
130: dehumidifier
140: Deodorizer
150: Gas storage
160: Surplus gas utilization equipment

Claims (2)

A trough filtrate reservoir for collecting the filtrate of the food garbage tear; A solid-liquid separator for solid-liquid separation of the desorption filtrate supplied from the desulfurization solution storage tank; A pulverizer for pulverizing particles having a predetermined size or larger in the solid-liquid separator and recycling the pulverized particles to a desalination / filtrate storage tank; A neutralizer for neutralizing the treated water separated in the solid-liquid separator; A heat dissolving device for solubilizing the sludge at a pH of the neutral region at a pressure of 18 to 22 kg / cm 2 and a temperature of 180 to 200 ° C by applying heat to the food waste desorption filtrate; A boiler for supplying heat required for the heat dissolving apparatus; A heat exchanger for cooling the treated water discharged from the thermal solubilizer; A pressurized floating tank in which air having a pressure of 3 to 5 kg / cm 2 is introduced into the heat-solubilization apparatus to float and remove flocculated matter containing oil in the treated water subjected to heat-solubilization treatment; An anaerobic digester for methane fermentation of the treated water discharged from the pressurized floating tank; A dehumidifier for removing moisture from the gas discharged from the anaerobic digester; And a deodorizer having activated carbon for deodorizing the dehumidified gas from the dehumidifier. The method according to claim 1,
Further comprising a coagulation reaction tank for introducing an inorganic coagulant, caustic soda, and a polymer between the thermal solubilizer and the pressurized floating tank to coagulate the food waste.

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