Methods and systems for disposing of incineration residues

Abstract

This invention provides a technology that can shorten the stabilization period by promoting the decomposition of incineration residue components by microorganisms when incineration residue is disposed of in landfills. [Solution] A method for disposing of incineration residue includes: burying the incineration residue in a landfill section established within a landfill; providing a sheet to cover the landfill surface of the incineration residue in the landfill section; and supplying water below the sheet using a sprinkler to maintain the moisture content inside the landfill below the sheet at 5-30%. The moisture content may be maintained at 10-25% by supplying water using a sprinkler.

Description

Technical Field

[0005]

[0001] This disclosure relates to a technology for landfill final disposal of incineration residues.

Background Art

[0002] Incineration residues such as bottom ash (main incineration ash) and fly ash (incineration fly ash) discarded from incineration facilities are landfilled in a semi-aerobic final disposal site, and through a stabilization period of about 30 years, the organic substances, inorganic salts, heavy metals, etc. in the incineration residues are reduced in concentration.

[0003] Patent Document 1 discloses a technology for pre-treating incineration residues and then landfilling them in a final disposal site. This pre-treatment artificially washes the incineration residues before landfilling. In the washing of incineration residues, in order to improve the washing efficiency, aeration and sprinkling of water on the incineration residues are carried out in parallel. The washing of incineration residues is carried out until the total organic carbon concentration (TOC) in the water leaching from the incineration residue layer falls below the reference concentration. After pre-treatment, the incineration residues are landfilled in a final disposal site. Sprinkling is carried out on the incineration residues after landfilling at a rate of 2 mm / day.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The technology described in Patent Document 1 aims to shorten the stabilization period by reducing the concentration of incineration residue components such as organic matter and heavy metals to a certain level. However, considering that the stabilization period means that gas generation and heat generation due to microbial reactions within the landfill subside, it is clear that the microorganisms present around the incineration residue components contribute to shortening the stabilization period of the incineration residue after landfilling. In this respect, the technology described in Patent Document 1, which does not focus on the function of microorganisms, has room for improvement.

[0006] One objective of this disclosure is to provide a technology that can accelerate the decomposition of incineration residue components by microorganisms and shorten the stabilization period when incineration residue is disposed of in a landfill. [Means for solving the problem]

[0007] The inventors analyzed countless microorganisms present in landfills and identified Alkalibacterium and Pseudomonas as promising candidates for microorganisms capable of decomposing incineration residue components. As a result, the inventors found that the stabilization period can be shortened by maintaining the incineration residue after landfill in an environment where these promising candidates can be activated. This disclosure is based on this finding.

[0008] The first aspect of this disclosure is a method for disposing of incineration residue, which has the following characteristics: The method described above includes: burying incineration residue in a landfill section established within a landfill; providing a sheet to cover the landfill surface of the incineration residue in the landfill section; and supplying water below the sheet using a sprinkler system to maintain the moisture content inside the landfill located below the sheet at 5-30%.

[0009] In the first aspect, the moisture content may be maintained at 10-25% by supplying water using the sprinkler system.

[0010] The second aspect of this disclosure is a system for disposing of incineration residue, which has the following features: The system comprises a sheet that covers the landfill surface of incineration residue in a landfill section provided within the landfill, and a sprinkler device that supplies water below the sheet, wherein the sprinkler device supplies water to maintain the moisture content inside the landfill below the sheet at 5-30%.

[0011] In a second respect, the sprinkler system may supply water in such a way that it maintains the moisture content at 10-25%. [Effects of the Invention]

[0012] According to this disclosure, by covering the landfill surface of incineration residue with a sheet and maintaining the moisture content inside the landfill at 5-20%, it is possible to protect microorganisms of the genera Alkalibacterium and Pseudomonas and regulate the humidity inside the landfill. Therefore, it is possible to shorten the stabilization period by maintaining an environment inside the landfill in which these microorganisms can be activated. [Brief explanation of the drawing]

[0013] [Figure 1] This is a block diagram showing an example configuration of a disposal system for incineration residue according to an embodiment. [Figure 2] This is a conceptual diagram illustrating the first configuration example of a final disposal site and the first example of landfill disposal of incineration residue at a final disposal site. [Figure 3] This is a conceptual diagram illustrating a second example of the configuration of a final disposal site and a second example of landfill disposal of incineration residue at a final disposal site. [Figure 4] This is a block diagram showing a second example configuration of a disposal system for incineration residue. [Figure 5] This is a block diagram showing a third example configuration of an incineration residue disposal system. [Modes for carrying out the invention]

[0014] Embodiments of this disclosure will be described in detail below with reference to the drawings. Elements common to each drawing are denoted by the same reference numerals, and redundant explanations are omitted.

[0015] 1. Example of system configuration Figure 1 is a block diagram showing an example configuration of an incineration residue disposal system according to an embodiment. In the example shown in Figure 1, the disposal system 100 comprises a final disposal site 10, a sprinkler system 20, a washing system 30, a water tank 40, a purification system 50, and a power generation system 60. The final disposal site 10 and the purification system 50, the purification system 50 and the water tank 40, the water tank 40 and the sprinkler system 20, and the water tank 40 and the washing system 30 are connected by piping. In addition, the power generation system 60 and the sprinkler system 20, the power generation system 60 and the washing system 30, and the power generation system 60 and the purification system 50 are connected by power transmission lines.

[0016] Final disposal site 10 is an open-type facility for landfill disposal of incineration residue AS. Final disposal site 10 is constructed within the landfill. Final disposal site 10 typically includes a groundwater collection and drainage facility, a groundwater collection pit, a leachate collection and drainage facility, a leachate collection pit, and a gas venting facility. The groundwater collection and drainage facility is for collecting and quickly removing water and spring water generated in the lower part of final disposal site 10. The groundwater collection pit is for monitoring the quality of groundwater. The leachate collection and drainage facility is for quickly collecting water WT1 spread on the landfill. The leachate collection pit is for sending water WT4 collected by the leachate collection and drainage facility to the purification device 50. The gas venting facility is for quickly removing gas generated in the landfill and supplying air to the inside of the landfill.

[0017] The sprinkling device 20 is a device for sprinkling the water WT1 in the water tank 40 onto the landfill. The sprinkling device 20 is, for example, a sprinkler installed in a net-like manner on the outermost surface of the landfill. The injection amount of the water WT1 from the sprinkling device 20 is appropriately adjusted so that the water content rate inside the landfill falls within a desired range (for example, 5 to 30%, preferably 10 to 25%, more preferably 10 to 15%). Here, the water content rate may be the average of values directly measured at a plurality of points inside the landfill, or a value estimated based on the amount of leachate water from the landfill. In the latter case, the amount of leachate water is measured in a leachate collection pit. Therefore, by specifying in advance the relationship between the amount of leachate water per day and the water content rate, the water content rate can be estimated from the amount of leachate water measured in the collection pit.

[0018] The washing device 30 is a device for washing the incineration residue AS (bottom ash, fly ash, etc. discarded from an incineration facility) before landfill. Examples of the washing device 30 include a mechanically washed type (for example, a spiral type, an injector type) device and an in-tank washing type device (immersing the incineration residue AS in a water tank for washing). The water washing can be performed using the water WT2 in the water tank 40. By washing the incineration residue AS with water before landfill, the treatment cost of the leachate water (that is, the construction cost and power consumption of the purification device 50) can be reduced compared to the case of landfill the incineration residue AS in an unwashed state. The washed incineration residue AS-W is transported to the final disposal site 10 by a moving body such as a truck. On the other hand, the water WT3 after water washing is sent to the purification device 50.

[0019] The water tank 40 is a tank for storing the water used in the disposal system 100. A plurality of water tanks 40 may be provided. The water WT5 treated by the purification device 50 is stored in the water tank 40. The water tank 40 may store water collected from a groundwater drainage facility (or a groundwater collection pit) or tap water.

[0020] The purification device 50 is a device that simultaneously purifies the discharged water (water WT3) from the cleaning device 30 and the discharged water (water WT4) from the final disposal site 10. In water WT3, ammonium nitrogen (NH4-N) elutes at about 30 to 100 mg / l together with organic substances (BOD, COD). Therefore, in the purification device 50, biological denitrification treatment that has been put into practical use in leachate treatment is performed. Here, in a normal nitrification treatment, denitrification treatment, and recarbonation treatment system, the power consumption of the blower air required for nitrification treatment is high. Also, as the GHG emission amount (emission amount in terms of CO2) due to the addition of an organic carbon source (methanol) required for denitrification treatment, there is an emission amount that cannot be ignored. Therefore, in the purification device 50, it is desirable to perform a denitrification treatment with less power consumption such as the anaerobic ammonia oxidation method (anammox method) and a treatment that does not require the addition of an organic carbon source (methanol) rather than the conventional aerobic / anaerobic treatment, in order to achieve decarbonization.

[0021] The power generation system 60 is a system that generates power using natural energy for the power consumed in the disposal system 100. The power generation system 60 is, for example, a solar power generation and energy storage system installed in a part of the landfill site. The solar power generation and energy storage system typically includes a solar panel, a power conversion device such as an inverter, and a storage battery that stores the generated power of the solar panel. Since at least the operation of the sprinkler device 20, the cleaning device 30, and the purification device 50 requires power, it is possible to reduce the running cost of the disposal system 100 by covering the power for the operation of these devices with the power generation system 60.

[0022] 2. Configuration example of the final disposal site and disposal example of incineration residue 2-1. First example Figure 2 is a conceptual diagram illustrating a first configuration example of the final disposal site 10 and a first example of landfill disposal of incineration residue AS-W in the final disposal site 10. Figure 2 shows a schematic cross-section of the final disposal site 10. In the example shown in Figure 2, landfill sections 11 and 12 are formed in the final disposal site 10. Landfill sections 11 and 12 are separated by a group of crushed stone 13. In addition to the function of separating the landfill sections, the group of crushed stone 13 also has the function of protecting the drainage pipe 14 for collecting leachate from the final disposal site 10. The drainage pipe 14 constitutes part of the leachate collection and drainage facility described above.

[0023] Incineration residue AS-W1 is buried in landfill section 11, and incineration residue AS-W2 is buried in landfill section 12. Both incineration residue AS-W1 and AS-W2 are examples of the incineration residue AS-W described above. A portable sprinkler system 21 is installed above incineration residue AS-W1, and a portable sprinkler system 22 is installed above incineration residue AS-W2. Both sprinkler systems 21 and 22 are examples of the sprinkler system 20 described above.

[0024] In the example shown in Figure 2, a sheet 15 is installed above the sprinkler device 21, and a sheet 16 is installed above the sprinkler device 22. Sheets 15 and 16 are provided to cover the surfaces of the incineration residues AS-W1 and AS-W2, respectively. Sheets 15 and 16 are at least waterproof and breathable. The waterproof properties of sheets 15 and 16 prevent rainwater from seeping through to the area below them. The breathability of sheets 15 and 16 allows gases, heat, and water vapor generated below them to be released into the atmosphere.

[0025] In the example shown in Figure 2, we consider the case where new incineration residue AS-W (AS-W3) is to be buried in the landfill area (planned landfill area) 17 above the landfill area 11. In this case, first, the sheet 15 and watering device 21 installed above the incineration residue AS-W1 are temporarily removed (STEP 1). Then, the crushed stone group 18 is installed above the crushed stone group 13 (STEP 1). Note that a space is formed in the upper right part of the crushed stone group 13 to ensure workability above the landfill area 12. When installing the crushed stone group 18, a drainage pipe for leachate may be installed above the crushed stone group 13.

[0026] Next, incineration residue AS-W3 is filled into landfill section 17 (STEP 2). Similar to incineration residues AS-W1 and AS-W2, incineration residue AS-W3 is an example of the incineration residue AS-W described above. Specifically, the landfilling of incineration residue AS-W3 involves placing the incineration residue AS-W3 into landfill section 17, spreading it to a predetermined thickness, and compacting it. It is desirable that incineration residue AS-W3 contains an intermediate cover layer of about 30 cm to promote the decomposition of incineration residue components by microorganisms and to ensure horizontal water permeability of the incineration residue layer.

[0027] Next, a final cover layer of approximately 100 cm is placed on the landfill surface of the incinerated residue AS-W3 after landfilling, and the watering device 21 is reinstalled above it (STEP 3). In addition, the sheet 15 is reinstalled above the watering device 21 to cover the landfill surface (STEP 3). Through these steps, the incinerated residue AS-W3 is landfilled in the landfill section 17.

[0028] 2-2. Second Example Figure 3 is a conceptual diagram illustrating a second configuration example of the final disposal site 10 and a second example of landfill disposal of incineration residue AS-W at the final disposal site 10. Similar to Figure 2, Figure 3 shows a schematic cross-sectional view of the final disposal site 10.

[0029] In the example shown in Figure 3, sheet 15 is installed above the sprinkler device 21, and sheet 16 is installed above the sprinkler device 22. Up to this point, it is the same as the example shown in Figure 2. In the example shown in Figure 3, a portable solar panel 61 is installed above sheet 15, and a portable solar panel 62 is installed above sheet 16. Solar panels 61 and 62 correspond to the solar panels included in a system when the power generation system 60 is configured as a solar power generation and energy storage system.

[0030] Similar to the example shown in Figure 2, the example shown in Figure 3 considers the case where new incineration residue AS-W (AS-W3) is to be landfilled in the landfill area (planned landfill area) 17. In this case, first, the sheet 15, watering device 21, and solar panel 61 installed above the incineration residue AS-W1 are temporarily removed (STEP 1). Then, a group of crushed stone 18 is installed above the group of crushed stone 13 (STEP 1).

[0031] Next, the incineration residue AS-W3 is buried in the landfill section 17 (STEP 2). This process is the same as the example shown in Figure 2. Subsequently, a final cover layer is provided on the landfill surface of the incineration residue AS-W3, and the watering device 21 and sheet 15 are reinstalled above it to cover the landfill surface (STEP 3). The solar panels 61 are also reinstalled above the sheet 15. Through these steps, the incineration residue AS-W3 is buried in the landfill section 17.

[0032] 3. Effects As previously described, the inventors have identified the following as promising candidates for microorganisms capable of decomposing incineration residue components: microorganisms of the genus Alkalibacterium (e.g., Alkalibacterium olivapovliticus) and microorganisms of the genus Pseudomonas (e.g., Pseudomonas spinosa). Therefore, these microorganisms present in the final cover layer on the landfill surface of the incineration residue AS-W decompose the incineration residue components of the AS-W, thereby stabilizing the AS-W.

[0033] In particular, according to the embodiment, the incineration residue AS-W is covered with sheets 15 and 16 that have at least waterproof and breathable properties, and the water WT1 sprayed from the watering device 20 is used to adjust the moisture content of the incineration residue AS-W to a desired range. As a result, an environment is maintained in which the above-mentioned promising candidate microorganisms can be activated. Consequently, the microbial decomposition of the incineration residue components of the incineration residue AS-W is promoted, and the stabilization period can be shortened. By shortening the stabilization period, it is also possible to reduce the CO2 emissions associated with the operation of the incineration residue disposal system and contribute to decarbonization.

[0034] 4. Other System Configuration Examples The application of this disclosure is not limited to the disposal system 100 shown in Figure 1. Figure 4 is a block diagram showing a second configuration example of a disposal system for incineration residues. In the example shown in Figure 4, water WT6 is supplied from the final disposal site 10 to the water tank 40. Specifically, water WT6 is rainwater. The supply of water WT6 to the water tank 40 can be achieved, for example, by collecting rainwater that flows naturally down from sheets (sheets 15, 16) provided on the landfill surface of the final disposal site 10.

[0035] Figure 5 is a block diagram showing a third configuration example of a disposal system for incineration residue. In the example shown in Figure 5, purification devices 51 and 52 are provided. Purification device 51 is a device that treats the wastewater (water WT3) from the washing device 30. Purification device 52 is a device that treats the wastewater (water WT4) from the final disposal site 10. The purification device 51 and the washing device 30, the purification device 51 and the water tank 40, the purification device 52 and the final disposal site 10, and the purification device 52 and the water tank 40 are connected by piping. In addition, the power generation system 60 and the purification device 51, and the power generation system 60 and the purification device 52 are connected by power transmission lines.

[0036] Unlike the example shown in Figure 1, in the example shown in Figure 5, the wastewater from the washing device 30 (WT3) and the wastewater from the final disposal site 10 (WT4) are treated separately by two types of purification devices. The treatment in purification device 51 may be a denitrification treatment with low power consumption, such as the anaerobic ammonia oxidation method, or a treatment that does not require the addition of an organic carbon source, or a conventional aerobic treatment. The treatment in purification device 52 may be a denitrification treatment with low power consumption, such as the anaerobic ammonia oxidation method, or a treatment that does not require the addition of an organic carbon source, or a conventional anaerobic treatment.

[0037] In the example shown in Figure 5, water WT7 treated by the purification device 51 and water WT8 treated by the purification device 52 are sent separately to the water tank 40. [Explanation of Symbols]

[0038] 10 Final disposal sites 11, 12, 17 Reclaimed land area 13,18 Kirikuriishi Group 14 Drainage pipes 15, 16 seats 20, 21, 22 Sprinkler system 30 Washing device 40 water tanks 50, 51, 52 Purification device 60 Power Generation Systems 100, 200, 300 disposal system AS Incineration Residue AS-W, AS-W1~AS-W3 Incineration residue after washing WT1~WT8 Water

Claims

1. The incineration residue is buried in a designated landfill area within the landfill site, A sheet is provided to cover the landfill surface of the incineration residue in the aforementioned landfill area, Using a sprinkler system, water is supplied below the sheet to maintain the moisture content inside the landfill located below the sheet at 5-30%. A method for disposing of incineration residue, characterized by including [a certain substance].

2. Before burying the incinerated residue in the aforementioned landfill area, the incinerated residue must be washed with water. The method for disposing of incineration residue according to claim 1, further comprising the above.

3. The leachate that seeps from the aforementioned landfill area and the wash water used to wash the incinerated residue are treated with a purification device. The water after the aforementioned purification treatment is supplied to the water tank. It further includes, The water supply from the sprinkler system is performed using the water in the water tank. The method for disposing of incineration residue according to feature 2.

4. The water supply from the sprinkler system is carried out using water from a water tank connected to the sprinkler system and capable of storing rainwater. A method for disposing of incineration residue according to claim 1 or 2, characterized by the features described above.

5. The water supply using the aforementioned sprinkler system maintains the moisture content at 10-25%. A method for disposing of incineration residue according to claim 1 or 2, characterized by the features described above.

6. A portable solar power generation panel is installed above the aforementioned sheet, The sprinkler system is operated using the electricity generated by the solar panels. The method for disposing of incineration residue according to claim 1, further comprising the above.

7. A portable solar power generation panel is installed above the aforementioned sheet, The purification device is operated using the electricity generated by the aforementioned solar panels. The method for disposing of incineration residue according to claim 3, further comprising the above.

8. When additional incineration residue is to be buried on the aforementioned landfill surface, the sheet and the solar panels located in the area where the additional incineration residue is to be buried will be moved. After the sheet and the solar panel are moved, additional incineration residue is buried in the designated landfill area. The sheet and the solar panels will be rearranged above the landfill surface of the additional incineration residue in the aforementioned planned landfill area. A method for disposing of incineration residue according to claim 6 or 7, further comprising the above.

9. The sheet is waterproof and breathable. A method for disposing of incineration residue according to claim 1 or 2, characterized by the features described above.

10. A sheet that covers the landfill surface of incineration residue in a landfill section established within a landfill site, A sprinkler system that supplies water below the sheet, the sprinkler system that supplies water to maintain the moisture content inside the landfill below the sheet at 5 to 30%, A disposal system for incineration residue, characterized by comprising the following:

11. The sprinkler system supplies water to maintain the moisture content at 10-25%. The incineration residue disposal system according to claim 10.

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