KR20030017076A - Apparatus for treating landfill leachate - Google Patents

Abstract

PURPOSE: A landfill leachate treatment apparatus using landfill gas is provided, which is characterized in that landfill leachate is evaporated by using landfill gas as heat source, leachate condensate is further treated by reverse osmosis membrane. CONSTITUTION: The system comprises an evaporator(50) equipped with an evaporator main body(10); a leachate treatment tank(20) installed in the evaporator main body(10); a plurality of evaporation tubes(30) installed traverse in the treatment tank(20) for the hot gas (G') to pass; a burner(40) equipped with a rapid flame ignition device(42) for generating flame made by burning landfill gas as a heat source; a filter device(70) connected to the evaporator(50) for filtering the condensate (W) of the evaporator(50) into penetrated water (W1) and re-feed condensate (W2).

Description

Landfill Leachate Treatment System {APPARATUS FOR TREATING LANDFILL LEACHATE}

The present invention relates to a leachate treatment apparatus for treating leachate by evaporation using landfill gas discharged from a landfill. More specifically, the leachate is evaporated from an evaporator equipped with a burner using the landfill gas as a heat source. After condensing through the condenser, the condensate is filtered again as a filter device, the permeate is discharged, and the concentrated water is returned to the evaporator to treat the leachate within the discharge limit, thereby reducing the leachate treatment cost. Relates to a device.

In general, the landfill leachate is treated using a biological method such as anaerobic or aerobic, and then treated with activated carbon adsorption or fenton oxidation.

However, the method of treating the landfill leachate using the biological method, the soda coal adsorption method, or the fenton oxidation method is mainly to remove the organic matter contained in the treated water. There has been a limit.

Therefore, in recent years, the leachate treatment method using reverse osmosis method has been researched and executed in addition to the organic matter removal method of the leachate, such reverse osmosis method also requires a separate post-treatment facility for treating the contamination of the reverse osmosis membrane and the concentrated water of the reverse osmosis system. Because of this, there is a difficult problem in the treatment of leachate.

On the other hand, the prior art for such a leachate treatment method is Korean Patent Publication No. 94-6146 (name; leachate treatment method generated from landfills), and Korean Patent Publication No. 97-10662 (name; landfill by reverse osmosis method) Leachate treatment method), Japanese Patent Laid-Open No. 7-116639 (name; leachate treatment method of landfill), Japanese Patent Laid-Open No. 9-225452 (name; leachate treatment facility of waste final disposal site), and Japanese Patent Laid-Open 6-320155 (name; method for treating membrane separation of leachate) and Japanese Patent Application Laid-open No. Hei 10-5792 (name; leachate treatment facility) and the like, the techniques disclosed in the above publications are described in the above-described chemical treatment techniques. It is not easy to meet the leachate treatment standards that are strengthened according to the current environmental pollution by the method based on it.

On the other hand, Korean Patent Publication No. 94-10031 (name: decompression steam compression, manure, livestock wastewater, industrial leachate treatment technology using the evaporation compression method) discloses an evaporation method for treating leachate through evaporation as in the present invention However, in the Patent Publication No. 94-10031, the configuration of the evaporator is different, and in particular, since the use of a separate energy source such as gas during evaporation of the leachate, there is a problem that the energy cost during the leachate treatment increases.

That is, the evaporation method for the leachate treatment used in the patent publication is an indirect evaporation method to produce a steam by burning a separate external heat source, that is, a gas, and then evaporate the leachate using this steam, the inside of the evaporator It is under pressure and saves energy than general evaporator by compressing evaporated steam with blower and using it as heat source steam.

However, such an evaporation method requires a lot of power for compressing the generated steam, in particular, because the size of the equipment according to the indirect evaporation method has to be large, there is a problem that the initial equipment investment cost increases, phase change in the evaporation method usually This requires a lot of energy. In general, about 50 to 90% of the operating costs of evaporators are replaced by the cost of producing heat energy.

On the other hand, landfill gas, which occupies most of landfills, is generated by anaerobic decay such as food waste and organic materials.The landfill gas is mainly composed of methane and carbon dioxide, and the calorific value is about 5,000 Kcal / ㎥. In particular, landfill gas generated from such landfills is a significant deterrent to reclaiming landfills and is a major cause of odor and fire, and is usually collected by landfill gas collection facilities and discharged or burned to the atmosphere. Is common.

Therefore, if the landfill gas is used as a heat source during the evaporation treatment of the leachate, it will be more preferable because it reduces the energy cost, odor and fire caused by the landfill gas.

The present invention has been made in order to improve the various problems as described above, the object of the present invention, by using the waste landfill gas discharged from the landfill as a heat source of the evaporator, it is possible to minimize the leachate treatment cost, the maintenance cost of the leachate treatment apparatus To provide a landfill leachate treatment system to reduce the

1 is a schematic diagram showing the overall configuration of the leachate treatment apparatus according to the present invention

Figure 2 is a block diagram showing an evaporator of the present inventors processing apparatus

Figure 3 is a schematic diagram showing a burner supply configuration of landfill gas in the present inventors processing apparatus

* Symbols for main parts of drawings *

1 ... Leachate Treatment System

20 .... leachate treatment tank 30 .... evaporation tube

40 .... Burner 42 .... Rapid Fire Ignition

50 .... evaporator 70 .... filter unit

As a technical configuration for achieving the above object, the present invention provides an evaporation main body, a leachate treatment tank installed in the evaporation main body and supplied with leachate, and a hot gas passed through the treatment tank and passing therein. An evaporator having a plurality of lines, and an evaporator having a burner having a separate flame rapid ignition means and installed to generate a flame as a heat source from the landfill gas supplied to one side of the evaporation tube; And,

By filtering the leachate evaporated and condensed in the evaporator treated with permeate and re-entry concentrated water to increase the leachate treatment efficiency; filter device connected to the evaporator;

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

Figure 1 is a schematic diagram showing the overall configuration of the leachate treatment apparatus according to the present invention, Figure 2 is a schematic diagram showing the evaporator of the treatment apparatus of the present invention, Figure 3 is a burner supply configuration of the landfill gas in the treatment apparatus of the present invention It is a schematic diagram shown.

Figure 1 schematically shows the overall configuration of the landfill leachate treatment apparatus 1 of the present invention, the apparatus 1 of the present invention is largely an evaporator 50 using the landfill gas (G) of the landfill as a heat source, and The condensed water evaporated through the evaporator 50 may be divided into a filter device 70 having improved sedimentation water treatment efficiency. The components 50 and 70 will be described in detail as follows.

First, the evaporator 50 is illustrated in FIGS. 1 and 2, and the evaporator 50 is again an evaporation main body 10, a treatment tank 20, an evaporation tube 30, and a burner 40. consist of.

As shown in FIG. 2, the evaporation base 10 of the evaporator 50 preferably has a refractory structure that can withstand high temperatures, and the evaporation base 10 as described above is burned. A flue 34 is installed in which hot gas (HOT-GAS) G 'is discharged to the atmosphere. Of course, although not shown in the drawing, a purge facility may be installed in the flue.

Next, as shown in FIGS. 1 and 2, the leachate treatment tank 20 of the evaporator 50 is installed in the evaporation main body 10 and filled so that the leachate W always maintains a constant level.

At this time, as shown in Figure 2, the supply pipe (22a) of the leachate storage tank 22 disposed adjacent to the evaporator 50 to supply the leachate (W) in the treatment tank 20 in the upper portion of the leachate treatment tank 20 ) Is connected.

In addition, a lower portion of the treatment tank 20 is connected to a connection pipe 26 connected to the scale separation tank 24 disposed adjacent to the evaporator 50 to remove the residues at the bottom of the treatment tank 20. The connection pipe 26 is connected to a treatment water injection pipe 28 having a plurality of nozzles 28a for injecting leachate from the treatment tank 20.

Next, the evaporator tube 30 of the evaporator 50, as shown in Figure 2, is installed across the upper side of the leachate treatment tank 20 to the inside of the evaporation main body 10, the evaporator tube 30 ) Is separated into several branches to increase the evaporation efficiency at the end of the gas conduit 32 which is integrally extended from the burner 40 to be described later.

By the way, the inside of the gas conduit 32 and the evaporation tube 30 will be described in detail later, but as the burner 40, the hot-gas (HOT-GAS) in which the landfill gas G is burned passes. The leachate is effectively evaporated through a plurality of lines of evaporation tube 30, and thus in the present invention, the landfill gas G is burned by hot gas without evaporating the leachate indirectly through a steam tube heated as a burner. -Since the gas G 'is directly evaporated through the evaporation tube 30, the installation is simplified and the efficiency is high.

Next, as shown in FIGS. 2 and 3, the burner 40 of the evaporator 50 uses the landfill gas G supplied to the gas conduit 32 of the evaporator 30 as a heat source. It is connected to the gas conduit 32 to generate a flame to generate a.

And, such a burner 40 is provided with a flame rapid ignition means 42 that is different from the pilot burner that is commonly used, such a flame rapid ignition means 42, as shown in FIG. It consists of a heating wire provided in the gas conduit 32 in front of the burner 40 so that it may be heated by flame F of (10), ie, a nichrome wire.

At this time, the flame rapid ignition means 42 of the nichrome wire is heated when the landfill gas G mixed at a ratio of about 50% methane and 50% carbon dioxide suddenly extinguishes the flame due to unstable proportions of the components. Nichrome wire 42 in the ignition of the flame rapidly serves as a normal pilot burner to keep the operation of the burner 40 at all times.

3, a gas supply pipe 44 is connected to the burner 40 of the evaporator 50, and the gas supply pipe 44 is connected to a hole hole 44a inserted into a landfill G. The dehumidifier 44b is connected to the landfill gas storage tank 46 connected through the gas filter 44c and the blower 44d so that the landfill gas G is directly processed and supplied to the burner 40.

Next, the filter device 70 of the apparatus 1 of the present invention is shown in FIG. 1, wherein the filter device 70 filters the leachate (W) evaporated and condensed in the evaporator 50 to permeate water. It is connected to the evaporator 50 to increase the leachate treatment efficiency by treating with (W1) and re-entry concentrated water (W2), the present invention uses a reverse osmosis filter device 70.

On the other hand, as shown in Figure 2, between the evaporator 50 and the filter device 70, a collection pipe 62 for collecting the vaporized treated water vapor is connected, the collection pipe 62 to cool the steam The condenser 64 and the condensate storage tank 66 which store the cooled process water are respectively provided, and the cooling tower 64a which circulates and supplies cooling water is connected to the said capacitor 64.

In addition, the filter device 70 is a treatment tank in the evaporator 50 to re-introduce the permeate discharge pipe 72 and the concentrated water for discharging the permeated water filtered through the evaporated condensed water to the treatment tank 20 ( Reprocessing pipe 74 is connected to 20 is made of a configuration that is connected to each.

Referring to the operation of the present invention made in the above configuration in detail as follows.

As shown in Figures 1 to 3, the leachate (W) leached from the landfill (T) is supplied to the leachate treatment tank 20 in the main body 10 of the evaporator 50 through the leachate reservoir 22, the drawing Although schematically shown in Figure 6, the leachate (W) of the treatment tank 20 to maintain the constant level always, that is, to maintain the same amount of evaporation and the amount of supply is always the same, for example installed in the treatment tank (20) The water level sensor (not shown) is connected to the opening and closing valve and the control unit (not shown) installed in the supply pipe (22a) of the reservoir 22 to perform this.

Next, as shown in FIGS. 1 and 3, the landfill gas G collected through the oil hole pipe 44a inserted into the landfill T is removed with moisture through the dehumidifier 44b, and then the gas filter ( After being supplied to the landfill gas storage tank 46 through 44c and the blower 44d, it is installed at the end of the gas conduit 32 installed in the main body 10 of the evaporator 50 through the gas supply pipe 44 and the evaporator ( 50) The landfill gas G is directly supplied to the burner 40 located outside.

Therefore, the burner 40 generates a flame F by using the landfill gas G as an energy source, and injects the hot gas G ′ into the gas conduit 32, at the end of the gas conduit 32. The evaporation tube 30, which is separated into multiple lines and reaches the flue 34 across the top of the treatment tank 20, is heated to evaporate the leachate W in the treatment tank 20.

At this time, as described above, when the flame (F) is interrupted because the components of the landfill gas supplied to the burner 40 is unstable, the heating wire that is a heated flame rapid ignition means, that is, the nichrome wire 42 is heated Therefore, the flame is rapidly reignified in the state where the landfill gas G is supplied, and thus the operation of the burner 40 can be kept constant at all times.

In addition, the lower portion of the treatment tank 20 is connected to the connection pipe 26 connected to the scale separation tank 24 arranged outside the evaporator 50, the evaporation residue in the treated water as a pump (P) Residues such as scale are supplied to the scale separation tank 24 to be externally processed, on the contrary, nozzles of the injection pipe 28 connected to the upper portion of the treatment tank 20 from the connecting pipe 26 into the evaporator 50. The leachate in the treatment tank is sprayed through the 28a to make the evaporation more efficient while contacting the lower evaporation tube 30 more extensively. In particular, the injected leachate is the evaporation tube 30 and the evaporation main body 10. Accompanied by the effect of deviating from the scales attached to the inner wall of the.

Next, the evaporated leachate vapors are collected in a condenser, that is, heat exchanger 64 through a steam collection pipe 62 connected to the evaporator 50, and are converted into condensate while being cooled as cooling water. The heat exchanger 64 includes a cooling tower 64a. ) Is continuously connected to the cooling water.

Next, the condensed water evaporated in the evaporator 50 and condensed in the condenser 64 is sent to the filter device 70 as a pump P, so that the permeate water W1 filtered in the reverse osmosis method is discharged through the discharge pipe 72. The concentrated water (W2) that is discharged to the outside and not filtered is sent to the treatment tank 20 of the evaporator 50 again through the reprocessing pipe 74 to be discharged to the permeate through evaporation and filtration again.

Hereinafter, an embodiment of the present invention will be described briefly as follows. However, the present invention is to investigate the effect of improving the water quality of treated water when treating a high concentration of leachate using the evaporator 50 having the landfill gas G as a heat source. The leachate (W) generated from landfill (T) was continuously tested and operated for 6 hours a day in consideration of safety.

The evaporator 50 used the landfill gas collected in the field as a heat source without a separate refining process. The evaporator 50 is a device having a processing capacity of up to 60 L / hr, and leachate is introduced into the treatment tank 20 in the evaporator 50. After the burner 40 was ignited, the evaporation main body was directly heated at atmospheric pressure.

In particular, in order to reduce the adherence of scale to the wall of the evaporator 50 and the evaporator main body 10 inside the evaporator 50, the leachate is discharged at a flow rate of 7,000 l / hr using the circulation pump P. The adhesion of the scale was reduced while spraying through the nozzle part 28a.

On the other hand, when the contents are concentrated in the scale separation tank 24 more than a certain amount, the evaporated residue is discharged to the outside and the supernatant is introduced into the evaporator 50 main body again. The evaporated water treated in the evaporator 50 was condensed through the heat exchanger 64 and introduced into the condensate storage tank 66.

Next, since the landfill gas G is not uniform in composition, instead of a pilot burner which requires a separate heat source, the flame is instantaneously turned off during operation by using a heating wire, that is, a nichrome wire 42, and the flame rapidly. To generate a stable heat source.

The water quality change of the leachate operated in this way was measured and the results are shown in Table 1 below.

Item Leachate Condensate Removal efficiency (%) Suspended matter (SS, mg / ℓ) 76 3.5 95.4 Chemical oxygen demand (CODcr, ㎎ / ℓ) 4,994 340 93.2 Ammonia nitrogen (NH ₄ ⁺ -N, mg / l) 2,173 810 62.7 Total nitrogen (T-N, mg / l) 2,175 435 80.0

As can be seen in Table 1, the suspended solids showed a high removal rate of 95.4% and the chemical oxygen demand of 93.2%. However, NH ₄ ⁺ -N and TN are respectively 62.7%, was a low-beam removal rate compared to 80.0%, which is NH ₄ ⁺ -N and NH ₃ because the parallel in relation -N been condensed and re-vaporized with a given evaporation to be.

In particular, according to the leachate discharge allowance NH ₄ ⁺ -N is to remove more than 90% of the leachate, the evaporator 50 alone can only remove about 62.7%, so can not be discharged as it is, condensate The reverse osmosis filter device 70 was used to treat permeate and concentrated water, as follows.

First, the permeate amount of the reverse osmosis filter device 70 was kept constant and operated in a constant flow rate method in which the pressure was changed. The module recovery rate was maintained at a relatively low 5% due to poor raw water quality, so that the permeate amount was 120 l / hr.

In addition, the reverse osmosis module has to supply a certain range of supply water according to the standard, the module used in the experimental apparatus, that is, the product module of the filter product is BW30-4040, the maximum inflow flow rate was 3,600 l / hr.

Therefore, the module inflow flow rate was supplied at 2,400 L / hr, which is 66% of the maximum inflow flow rate, and the concentrated water valve (not shown) was adjusted so that the permeate water was 120 L / hr, and 2,200 L in the concentrated water 2,280 L / hr. / hr was circulated and 80 ℓ / hr was discharged back to the reservoir 22 to analyze the water quality of the feed water and the permeate water while maintaining the recovery rate of the reverse osmosis filter apparatus 70 to 60%. Table 2 below.

Item Feed water Permeate Removal efficiency (%) Suspended matter (SS, mg / ℓ) 3.5 0 100 Chemical oxygen demand (CODcr, ㎎ / ℓ) 340 3.7 98.9 Ammonia nitrogen (NH ₄ ⁺ -N, mg / l) 810 194 76.1 Total nitrogen (T-N, mg / l) 435 61.3 85.9

Therefore, it can be seen that the removal efficiency of ammonia nitrogen is 76.1%, the removal rate of total nitrogen is 85.9%, it can be seen that the efficient removal of nitrogen components.

Therefore, the results of the treatment of the leachate through the evaporator 50 in Table 1 and the contaminant removal efficiency of the entire apparatus 1 of the present invention filtered through the filter device 70 in Table 2 are shown in Table 3 below.

Item Feed water Permeate Removal efficiency (%) Suspended matter (SS, mg / ℓ) 76 0 100 Chemical oxygen demand (CODcr, ㎎ / ℓ) 4,994 3.7 99.9 Ammonia nitrogen (NH ₄ ⁺ -N, mg / l) 2,173 194 91.0 Total nitrogen (T-N, mg / l) 2,175 61.3 97.2

As a result, as can be seen in Table 3, the removal rate of NH ₄ ⁺ -N was 91.0%, it was found that the discharge limit was satisfied, and finally, suspended solids, chemical oxygen demand can be sufficiently processed through the evaporation method, in particular By using the filter device 70 in the present invention, the nitrogen removal efficiency is increased, and the treatment can be performed within a standard value. Since the device 1 of the present invention uses the gas as a heat source directly, the energy cost is reduced, and It can be seen that the treatment efficiency is quite high.

Thus, the landfill leachate treatment apparatus of the present invention provides an advantage of reducing the energy cost of the leachate treatment cost by treating the leachate through the evaporator using the landfill gas of the landfill as a heat source.

In addition, while reducing the energy cost by treating the evaporated condensed water of the leachate back to the reverse osmosis device, it provides an effect to maximize the treatment efficiency of the leachate.

Finally, instead of the pilot burner of the burner used for evaporation, the nichrome wire is used to rapidly ignite it when extinguishing the flame, thereby providing an excellent effect of simplifying the structure of the evaporator burner device to reduce the cost of manufacturing the equipment. It is.

While the invention has been shown and described with respect to specific embodiments thereof, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit or scope of the invention as set forth in the claims below. I would like to know that those who have knowledge of this can easily know.

Claims (6)

The evaporation base 10, the leachate treatment tank 20 installed in the evaporation body 10 and supplied with the leachate W, and across the treatment tank 20 and inside the hot-gas G ' ) Is installed so as to generate a flame to generate hot-gas as a heat source from the evaporation tube 30 of a plurality of lines and the landfill gas G supplied to one side of the evaporation tube 30 as a heat source, and a separate flame An evaporator 50 having a burner 40 having a rapid ignition means 42; And, The filter device 70 connected to the evaporator 50 to filter the leachate evaporated and condensed by the evaporator 50 to treat the permeate water W1 and the re-entry concentrated water W2 to increase the leachate treatment efficiency. Landfill leachate treatment apparatus characterized in that consisting of; The supply pipe of the leachate storage tank 22 disposed adjacent to the evaporator 50 to supply the leachate (W) in the treatment tank 20 to the upper portion of the leachate treatment tank 20 of the evaporator 50 ( 22a) is connected, The lower portion of the treatment tank 20 is connected to the connecting pipe 26 is connected to the scale separation tank 24 disposed adjacent to the evaporator 50 to remove the residues of the bottom of the treatment tank 20, the connecting pipe (26) is a leachate treatment apparatus, characterized in that the treatment water injection pipe 28 having a plurality of nozzles (28a) for injecting the leachate from the treatment tank 20 is connected to According to claim 1, Between the evaporator 50 and the filter device 70 is connected to the collecting pipe 62 for collecting the evaporated treated water vapor, the collecting pipe 62 is condenser 64 for cooling the steam And condensate treatment tanks 66 for storing the cooled treatment water, respectively, The condenser 64 is a leachate treatment apparatus, characterized in that the cooling tower 64a for supplying purified water is connected. 4. The filter device (70) according to claim 1 or 3, wherein the filter device (70) is configured to re-inject the permeated water discharge pipe (72) and the concentrated water into the treatment tank (20) for discharging the filtered permeated water. Leachate treatment apparatus characterized in that the reprocessing pipe 74 is connected to the treatment tank 20 in the evaporator 50 is installed respectively The flame rapid ignition means (42) of the burner (40) comprises a heating wire installed in front of the burner (40) so as to be heated by the flame (F) of the burner (10), and the burner (40). Leachate treatment apparatus, characterized in that configured to quickly re-ignite the flame in the heated state when the flame is stopped The dehumidifier (44b) of claim 1, wherein a gas supply pipe (44) is connected to the burner (40) of the evaporator (50), and the gas supply pipe (44) is connected to a hole (44a) inserted into a landfill (G). Leachate treatment device characterized in that the landfill gas (G) is supplied to the burner 40 is connected to the landfill gas storage tank 46 connected via the gas filter 44c and the blower (44d)