JPH09150124A - Waste disposition plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease the leaching water from waste and to prevent the pollution of an ambient environment. SOLUTION: The surface of final covering earth 12 is provided thereon with a moisture permeable sheet 13 which allows the transpiration of steam but does not allow the passage of water, such as rainwater. The admission of the rainwater, etc., into a throwing pit 2 is prevented by the moisture permeable sheet 13. The moisture in the throwing pit 1 is gradually emitted to the atm. through the moisture permeable sheet 13 by the transpiration effect. As a result, the leaching water from the waste 3 is decreased. The transpiration is further accelerated by pipes 7 for transpiration rising from the bottom in the throwing pit 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste disposal site, and more particularly to a structure for reducing the amount of leachate.

[0002]

2. Description of the Related Art Conventionally, for example, waste has been dumped into a dump pit formed by digging into the ground to dispose of it in a landfill. In this type of waste disposal site, when water such as rainwater enters the dumping pit, water containing harmful substances that have melted out of the waste seeps into the outside soil and pollutes the surrounding environment such as groundwater pollution. May be caused.

Therefore, conventionally, for example, Japanese Unexamined Patent Publication No. 4-371607.
As described in the publication, etc., lay a waterproof sheet made of synthetic rubber or the like on the ground inside the dump pit,
Water is prevented from leaching from the dump pit to the soil outside. However, due to various factors such as ground subsidence, waste bite, plants and small and small animals, and deterioration of the impermeable sheet itself over time, there is a risk that the impermeable sheet will be damaged. Contaminated water in the dump pit will flow out from the location, which will lead to groundwater contamination.

At the waste disposal site, soil covering and intermediate soil covering are performed on the same day as the landfill, and final soil covering is performed after the landfill is completed. These soil coverings formed on waste materials have conventionally been performed by earth and sand. But,
Sediment is more or less water permeable, so rainwater will enter the dump pit. As described above, the infiltration of rainwater into the dump pit is a basic cause of pollution due to leachate.

On the other hand, in Japanese Patent Laid-Open No. 367775/1992, the waste is covered with a waterproof and breathable sheet in order to prevent the permeation of rainwater and to diffuse the gas generated from the waste. , It is described that a final soil covering is performed on this sheet. However, since the soil is covered on the sheet at the waste disposal site described in the publication, when there is precipitation, water is contained in the soil of the covering soil, and this water is hard to be discharged. Therefore, the soil and sand of the soil cover easily flows out along with the water. Also, if water is contained in the cover soil, gas including water vapor in the dump pit will not be released smoothly.

[0006] Further, in Japanese Patent Laid-Open No. 5-138143, for the same purpose, waste is covered with a sheet obtained by adhering a non-breathable waterproof sheet and a breathable waterproof sheet, and the sheet is covered with sand or the like. It is described that the final soil covering is performed via the water-permeable material. Then, the rainwater and the like that permeate the final cover soil are discharged to the peripheral water collection and drainage ditch via the water-permeable material. However, if it is necessary to flow a water-permeable material such as sand to the surrounding drainage channels,
Rainwater is not discharged smoothly, and sand is likely to flow out.

[0007] Further, the waste material is compressed and sinks due to aging, and this sinking may cause breakage and tearing of the sheet. The rupture of this sheet should be repaired,
When the sheet is covered with soil, it is difficult to know which part of the sheet under the soil is broken, and the repair work is troublesome.

[0008]

As described above, since the conventional waste disposal site is covered with earth and sand,
There was a problem that infiltration of rainwater, which causes pollution, is likely to occur. Further, as described in JP-A-4-367775, the waste is covered with a waterproof and breathable sheet,
When the final soil covering is performed on this sheet, there is a problem that water is likely to be accumulated in the soil and the soil of the soil is likely to flow out, and gas including water vapor in the dumping pit is not smoothly released.

The present invention is intended to solve such problems, and an object of the present invention is to provide a waste disposal site capable of reducing the amount of leached water from wastes and preventing pollution of the surrounding environment.

[0010]

In order to achieve the above-mentioned object, the waste disposal site according to the invention of claim 1 is provided on the same day soil, intermediate soil or final soil covering the discarded waste, or on these soils. As a cover soil itself, a moisture-permeable sheet is laid to prevent the rainwater from passing through, but to prevent rainwater from entering the waste, and also to evaporate the water in the waste to leach it from the waste. It reduces water.

The moisture permeable sheet prevents rainwater and the like from directly entering the waste disposal site. On the other hand, the water in the waste disposal site is discharged to the atmosphere through the moisture permeable sheet by the transpiration action. As a result, the amount of water in the waste disposal site is reduced, the amount of leachate is reduced, and the infiltration of wastewater to the outside is suppressed.

[0012] The invention of claim 2 is, in the waste disposal site of the invention of claim 1, in addition to the final cover soil, on the same day soil cover, intermediate soil cover or at the end most soil cover, or as the soil cover itself in multiple layers. A moisture permeable sheet is laid.

On the same day as the soil cover or the intermediate soil cover, or
The moisture permeable sheet laid as the soil cover itself can reduce the leachate from the waste even in the middle stage of dumping the waste. Along with this, the moisture permeable sheet laid on the final cover soil or the final cover soil or as the final cover or the final cover soil itself can reduce the leachate after the disposal of the waste is completed.

According to a third aspect of the present invention, in the waste disposal site of the first or second aspect of the present invention, the edges of a plurality of moisture permeable sheets are superposed so as to be mutually displaceable to prevent the moisture permeable sheet from tearing. Is.

The dumped waste subsides over time, and as a result, the moisture-permeable sheet is displaced or stretched, but at that time, the moisture-permeable sheet does not tear and the edges of the plurality of moisture-permeable sheets are not cleaved. Are displaced from each other and a gap is created between them. Since the position where the gap is formed is the position between the plurality of moisture permeable sheets, even if the moisture permeable sheet is covered with soil, it is possible to guess. Therefore, when a predetermined subsidence occurs, a moisture permeable sheet is laid again above the position between the plurality of moisture permeable sheets to prevent rainwater and the like from entering.

According to a fourth aspect of the present invention, in the waste disposal site according to any one of the first to third aspects of the present invention, a vaporization pipe for vaporizing water vapor is set up near the ground where the waste is dumped. Is.

Through the evaporation pipe, water is evaporated from the bottom to the upper layer in the waste disposal site.

In order to achieve the above-mentioned object, the waste disposal site of the invention of claim 5 allows water to pass through on the same day soil, intermediate soil or final soil covering the discarded waste, or as the soil itself. Not laying a water-blocking sheet, a vaporization pipe that vaporizes water vapor is pierced through the water-blocking sheet from near the ground where waste is dumped, and while preventing rainwater from entering the waste, By evaporating the water in the waste, reducing the leachate from the waste, and overlapping the edges of multiple water-blocking sheets so that they can be displaced from each other.
This is to prevent tearing of the waterproof sheet.

The water blocking sheet prevents rainwater and the like from directly entering the waste disposal site. On the other hand, the water in the waste disposal site is discharged to the atmosphere by the evaporation action through the evaporation pipe. As a result, the amount of water in the waste disposal site is reduced, the amount of leachate is reduced, and the infiltration of wastewater to the outside is suppressed. Also, the dumped waste subsides over time, and as a result, the water-impermeable sheets are displaced or stretched, but at this time, the water-impermeable sheets do not tear and the edges of the multiple water-impermeable sheets are separated. They are displaced from each other and a gap is created between them. Since the position where this gap is formed is the position between the plurality of water-impervious sheets, even if the water-impermeable sheet is covered with soil, it is possible to estimate the position. Therefore, when a predetermined subsidence occurs, a waterproof sheet is laid again above the position between the plurality of waterproof sheets to prevent rainwater and the like from entering.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the waste disposal site of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is the ground, and 2 is a dump pit for dumping the waste 3. The dumping pit 2 may be one in which the ground 1 is artificially excavated and dug down, or one in which natural concave topography is used. There is a seepage control work on the ground 1 on the inner surface of the dumping pit 2.
For example, after the ground 1 is subjected to shaping or the like, a water impervious sheet 4 is laid on the ground 1, and a protective earth and sand layer 5 is formed on the water impervious sheet 4. The water blocking sheet 4 is made of elastic synthetic rubber or the like, and has neither water permeability nor air permeability.

Reference numeral 6 denotes a leachate collection / drainage facility consisting of a perforated pipe or the like. This leachate collection / drainage facility 6 is provided at the bottom of the dumping pit 2 above the water-blocking sheet 4, and is shown in the figure. Not leading to a leachate treatment facility. In addition, 7 is a pipe for evaporation which also serves as a vertical leachate collection and drainage pipe and a vertical degassing facility. This evaporation pipe 7 stands up from the leachate collection and drainage facility 6. Furthermore, 8 is a peripheral drainage channel, and this peripheral drainage channel 8 is provided so as to surround the dumping pit 2 on the ground surface.

When the waste 3 is to be reclaimed, the soil and sand are used to cover the soil and the intermediate soil 11 on the same day at any time, and after the landfill is completed, the final soil 12 is provided. The same day soil cover is performed every shorter period than the intermediate soil cover 11.

A moisture permeable sheet 13 is laid on the final soil 12 that finally covers the discarded waste 3.
As the moisture permeable sheet 13, for example, a sheet made of polyolefin in which a myriad of micropores having a pore diameter of 30 μm or less are chemically or mechanically punched, or a sheet of synthetic rubber such as vinyl chloride is subjected to needling processing. It is possible to use various materials such as those obtained by continuously spinning polyethylene or polypropylene into a sheet and then bonding the fibers to each other at high temperature and high pressure. Such a moisture permeable sheet 13 does not allow water such as rainwater to pass through, but has a property of passing gas including water vapor.

Normally, a plurality of moisture permeable sheets 13 must be spliced together to cover the entire final soil 12.
FIG. 2 shows an example of construction of the moisture permeable sheet 13 (first embodiment).
Is shown. In the first embodiment, one side edge portion of the moisture permeable sheet 13 is put into the groove 16 formed on the final cover soil 12 and covered with the soil 17 to be pressed. Further, the other side edge portion of the moisture permeable sheet 13 is adhered to one side edge portion of the adjacent moisture permeable sheet 13. Reference numeral 18 indicates an adhesive portion. For this adhesion, heat sealing, hot melt, adhesive or the like can be used. Furthermore, the other side edge portion of the moisture permeable sheet 13 adjacent to the peripheral water collecting and draining groove 8 is
The inner surface of the peripheral water collecting and draining groove 8 is bonded with an adhesive 19 or the like. This prevents rainwater or the like from entering through the joints of the moisture permeable sheet 13. Further, FIG. 3 shows another example (second embodiment) of the construction of the moisture permeable sheet 13.
In this second embodiment, one side edge of the moisture-permeable sheet 13 is anchored.
It is pressed on the final soil cover 12 by 20. Other configurations are the same as in the first embodiment. The plurality of moisture-permeable sheets 13 to be spliced do not need to be bonded to the entire edge portion without a gap, and may be bonded only partially.
Further, the plurality of moisture-permeable sheets 13 may be joined together by snapping or the like.

Next, the evaporation pipe 7 will be described with reference to FIG.
It will be described based on. This evaporation pipe 7 is an outer pipe
It has a double structure of 26 and inner pipe 27. Outer pipe 26
Is made of a fume tube having a large number of holes 28 penetrating the inside and outside, a plastic tube, a mesh tube, or the like, and has rigidity. On the other hand, the inner pipe 27 is made of the same material as the moisture permeable sheet 13 and allows gas including water vapor to pass through but does not allow water such as rainwater to pass through. The diameter of the evaporation pipe 7 is 200 to 2000 mm. And the pipe
26 and 27 are added to the upper part together with the covering material as the landfilling of the waste 3 progresses. Finally, the pipe 26,
The upper end of 27 goes above the final soil cover 12. It should be noted that the surface of the inner pipe 27 having an uneven shape is effective for vaporization of water vapor since the surface area becomes larger. Further, when the upper end of the evaporation pipe 7 is exposed above the moisture permeable sheet 13, a cover or the like is necessary to prevent infiltration of rainwater and the like. Further, in this embodiment, the evaporation pipe 7 is also used as the vertical degassing facility, but both may be provided separately.

After the final cover soil 12 and the moisture permeable sheet 13 have been constructed, even if rainwater or the like falls on the final cover soil 12 and the moisture permeable sheet 13, since this water cannot pass through the moisture permeable sheet 13, the final cover soil 12 and the disposal pit 2 It does not enter the inside directly, but is discharged by the peripheral water collection and drainage groove 8. In addition, even if a small amount of water penetrates through the gap between the joined moisture-permeable sheets 13,
There is not much problem. On the other hand, the water in the dump pit 2 is discharged to the atmosphere through the moisture permeable sheet 13 by the evaporation action. At that time, since the final cover soil 12 is also prevented from getting wet, the sediment of the final cover soil 12 does not flow out, and
Evaporation is reliably performed through the moisture permeable sheet 13. Also,
The evaporation into the atmosphere also occurs inside the inner pipe 27 of the evaporation pipe 7. Therefore, water will be evaporated all over from the bottom to the upper layer in the dump pit 2. As a result, the amount of water in the dump pit 2 is reduced, the inside of the dump pit 2 is dried, and the leachate is reduced. Therefore, even if the water-blocking sheet 4 is damaged, the infiltration of sewage to the outside is suppressed, and contamination of the surrounding environment such as groundwater contamination is prevented. Further, the outflow of the sediment layer 5 of the ground 1 of the dump pit 2 can be suppressed, and the leachate collection / drainage facility 6 can be prevented from being clogged. As a result, the leachate collection / drainage facility 6 itself can be reduced, the construction thereof can be facilitated, and the maintenance can be facilitated.

The gas generated from the waste 3 in the dump pit 2 is also discharged to the atmosphere via the moisture permeable sheet 13 and the evaporation pipe 7. Water may collect between the outer pipe 26 and the inner pipe 27 of the evaporation pipe 7, but this water evaporates as described above, or the leachate treatment facility is passed through the leachate collection / drainage facility 6. Sent to.

Then, after several years, for example, after it is confirmed that the dumped waste 3 is chemically and physically stabilized and no leachate is produced, further soil cover (up to last soil cover) is performed. You can do it, plant trees, and build various facilities.

In order to effectively vaporize the vaporizing pipe 7, a fan may be provided at the upper end portion of the vaporizing pipe 7 exposed above the ground to carry out suction blowing. In this case, a part of the plurality of evaporation pipes 7 may be used for blowing air from the atmosphere into the dump pit 2, and another part may be used for blowing air from the dump pit 2 to the atmosphere.

In the above embodiment, the inner pipe 27 of the evaporation pipe 7 is made of a material that allows water vapor to pass but rainwater does not. However, a material having excellent water permeability, such as cardboard, is used. It may be made of compressed paper.
As a result, the inner pipe 27 becomes
Despite the presence of the water, the leachate that has passed through the hole 28 of the outer pipe 26 permeates the inner pipe 27, and the water is also evaporated from other than the portion corresponding to the hole 28, so that the evaporation is ensured. .

Furthermore, in the above-mentioned embodiment, the moisture permeable sheet 13 is gas permeable, but it may be gas impermeable. For example, after impregnating a non-woven fabric with an aqueous solution of a completely saponified product of polyvinyl alcohol (PVA),
This may be dried or coagulated with salt to form the moisture permeable sheet 13, or the moisture permeable sheet 13 made of completely saponified PVA may be molded without using a nonwoven fabric. The product obtained by drying or coagulating the completely saponified aqueous solution of PVA in this way has elasticity and dissolves in hot water, but is insoluble in cold water and only swells. And, by the drying from the swollen state, it eventually has a property of passing water vapor. However, it has a property that it does not allow water in the liquid phase to directly pass therethrough, and does not allow ions, salts, and organic solvents, including gases, to pass therethrough.

In this case, the landfilled waste 3
Since the gas generated from the gas cannot pass through the moisture permeable sheet 13, it is discharged into the atmosphere through the evaporation pipe 7. However, when the landfilled waste 3 is stabilized and the gas generated from it becomes less,
The inner pipe 27 of the evaporation pipe 7 may be replaced with a completely saponified product of PVA. Alternatively, in the case of waste 3 which originally generates less gas, PVA is used from the beginning.
The inner pipe may be made of a completely saponified product.

As the material of the permeable sheet 13 having similar properties, in addition to PVA, for example, cellophane or a water-soluble polymer compound such as sodium alginate, methyl cellulose, carboxymethyl cellulose, chitosan is gelated or insolubilized. Various things such as those made to be used are used.

Further, in any of the above-mentioned embodiments, it is not necessary to completely and completely cover the final covering soil 12 with the moisture permeable sheet 13, and a part of the final covering soil 12 may be exposed. For example, in order to stabilize waste 3 by aerobic decomposition, it is better to have a certain amount of moisture, and the dump pit 2
Stabilization of the waste 3 can be promoted by allowing a certain amount of water to flow therein.

Further, the above-mentioned embodiment is applicable to the existing waste disposal site because the moisture permeable sheet 13 is applied on the final cover soil 12.

However, as in the third embodiment shown in FIG.
In addition to the final soil 12, the same moisture permeable sheet 13 can be applied on the soil on the same day or the intermediate soil 11. The moisture-permeable sheet 13 on the soil or the intermediate soil 11 on the same day may be removed before further landfilling the waste 3. That is, the landfill first proceeds in a planar manner, and then proceeds upward. However, the moisture permeable sheet 13 on the soil cover or the intermediate soil cover 11 on the same day starts from the landfilled waste 3 until the landfill above it starts. The purpose is to reduce the leachate. As a result, the leachate after the landfill of the waste 3 is completed can be further reduced. The moisture permeable sheet 13 on the soil covering on the same day or the intermediate soil 11 may be left as it is for every several layers without removing all.

Along with this, the same day soil cover or intermediate soil cover
By laying a breathable sheet 13 on top of 11 to surely achieve the purpose of preventing scattering of waste 3 and protection from flies and birds, while reducing the amount of earth and sand used for immediate soil cover or intermediate soil cover 11. It is possible to cover the soil on the same day or intermediate soil
The thickness of 11 itself can be made thin. For example, the conventional 50cm thickness can be reduced to about 5cm. This allows
Waste of the space in the dump pit 2 can be reduced, and this space can be effectively used.

Further, if the moisture permeable sheet 13 is laid in a plurality of layers, even if water should leak due to damage to the moisture permeable sheet 13 or the like, the lower the layer, the smaller the effect of water leakage. It will become. Therefore, it is possible to more reliably prevent the leaching into the outside soil. Even if water infiltrates the waste 3 in the upper layer in the dump pit 2 during the rainy season, for example, the waste 3 dries in the subsequent summer, so that the lower layer is not changed throughout the year regardless of changes in precipitation. Waste 3 can be kept dry.

Next, a fourth embodiment of the waste disposal site of the present invention will be described with reference to FIG. In the fourth embodiment, the inner pipe 27 of the transpiration pipe 7 is made of a water-immersive material such as compressed paper, and the water-permeable material such as compressed paper connected to the inner pipe 27 is also used. The transpiration sheet 31 consisting of is provided radially from the upper end or the intermediate portion of the transpiration pipe 7. This transpiration sheet
31 is located on the lower side, the middle part or the upper side of the soil cover or the intermediate secondary soil 11 or the final cover soil 12 on the same day.
Position below 13. The final soil cover is shown in Fig. 6.
The case where it is laid on the upper side of 12 is illustrated.

The water that has penetrated into the inner pipe 27 of the evaporation pipe 7 penetrates to the evaporation sheet 31, but since this evaporation sheet 31 is located adjacent to the lower side of the moisture permeable sheet 13, Evaporation is effective.

Next, a fifth embodiment of the waste disposal site of the present invention will be described with reference to FIGS. 7 and 8.
In the fifth embodiment, a water-permeable layer 41 through which water such as rainwater can flow is formed on the moisture-permeable sheet 13 laid on the intermediate soil 11 or the final soil 12, and the soil-sand covered soil is further formed on the water-permeable layer 41. I did 42. This construction is preferably carried out after it has been confirmed that almost no leaching water from the waste 3 has disappeared, half a year or one year after the installation of the moisture-permeable sheet 13. For the formation of the water-permeable layer 41, a water-permeable mat, a perforated plate, crushed stone, pebbles, or waste plastic contained in the waste 3 can be used. Then, in the water permeable layer 41, a collection / drainage pipe 43 made of a perforated pipe or the like is passed in an appropriate arrangement for collecting and draining. These collection and drainage pipes 43 communicate with the evaporation pipe 7 which also serves as a vertical leachate collection and drainage pipe. The transpiration pipe 7 has a diameter of about 1 to 3 m so that a person can put it in, and is firmly fixed on the ground 1 by the pile 44 and the foundation 45.

In the fifth embodiment, as in the first embodiment and the like, the moisture permeable sheet 13 can prevent water such as rainwater from entering the landfilled waste 3, and
The water already present in the waste 3 can be discharged by the transpiration action through the moisture permeable sheet 13, thereby reducing the leachate from the waste 3. Moreover, water such as rainwater that has penetrated the upper soil 42 is promptly discharged from the water permeable layer 41 through the water collection and drainage pipe 43 into the evaporation pipe 7. Therefore, it is possible to prevent the soil and sand from flowing out of the cover soil 42, and to quickly return the cover soil 42 to the normal dry state to promote the transpiration action from the waste material 3.

Further, by providing the moisture permeable sheet 13 on the intermediate soil 11, it is possible to reduce the leachate at each stage of the landfill, and to reduce the total amount of the leachate during the landfill period and the long period thereafter. It Moreover, since the drying of the waste 3 proceeds from the lower part in the dumping pit 2, the risk that the leachate from the waste 3 leaks to the outside can be further reduced. Further, since the vaporizing pipe 7 has a diameter that a person can enter, a person can enter the vaporizing pipe 7
It is possible to visually confirm whether or not the leachate is coming out from the outlet of the water collection and drainage pipe 43. For example, even if leachate is coming out from the upper drainage pipe 43, if leachate is not coming out from the lower drainage pipe 43, it can be confirmed that there is little risk of the leachate leaking to the outside. .

Further, in the construction of the fifth embodiment, after the landfilling is completed, it is confirmed that the discarded waste 3 is chemically and physically stabilized and no leachate is produced, and then the tree planting is performed. It is also suitable to be applied to the last covering soil for the construction of various facilities.

Next, a sixth embodiment of the waste disposal site of the present invention will be described with reference to FIG. The parts corresponding to those in the fifth embodiment are designated by the same reference numerals and the description thereof will be omitted. In the sixth embodiment, a plurality of moisture permeable sheets 13 are laid on the immediate soil cover, the intermediate soil cover 11 or the final soil cover 12 that covers the waste 3 dumped in the dump pit 2. The width of each moisture permeable sheet 13 is, for example, about 100 m.
Then, as shown in FIG. 9A, the adjacent moisture-permeable sheets
The edges of 13 are simply stacked one above the other and are displaceable relative to each other. The edges of the adjacent moisture-permeable sheets 13 may be adhered to each other, but when the load is applied, the moisture-permeable sheet 13 itself must be weakly adhered so that the moisture-permeable sheet 13 itself ruptures and peels before being cleaved. There is. In addition, the moisture permeable sheet 13
Has a substantially V-shaped cross section in which both sides are inclined toward the center.

Six months or one year has passed since the moisture permeable sheet 13 was laid, and after it was confirmed that the leaching water from the waste 3 had almost disappeared, the same as in the fifth embodiment. A water collection and drainage pipe 43 is provided at the lowermost part of the upper central portion of the moisture permeable sheet 13 to form a water permeable layer 41, and a soil cover 42 is provided as a final soil cover on the water permeable layer 41.

The waste 3 dumped in the dump pit 2 sinks with time, but as a result, the moisture permeable sheet 13 is displaced or stretched. At that time, the moisture-permeable sheet 13 does not break and tear, and the edges of the plurality of moisture-permeable sheets 13 are displaced with respect to each other as shown in FIG. Since the position where this gap is formed is the position between the plurality of moisture permeable sheets 13, even if the soil 42 is provided on the moisture permeable sheet 13, it is possible to obtain an estimate. Therefore, when a predetermined subsidence occurs, as shown in FIG. 10, it is considered that a gap is formed between the plurality of moisture permeable sheets 13 and these moisture permeable sheets 13
The moisture permeable sheet 13 is laid again in the same manner above the position between them, and the water collection and drainage pipe 43 and the like are provided. This allows
Water such as rainwater is prevented from entering the waste 3 in the dump pit 2. That is, even if rainwater or the like enters the cover soil 42 through the gap between the newly laid upper moisture-permeable sheets 13, this rainwater is blocked by the lower moisture-permeable sheet 13 and drained from the drainage pipe 43. Therefore, it is prevented that the waste 3 penetrates.

If one large integrally permeable sheet is used, when the permeable sheet is stretched, ruptured and cleaved as the waste subsides, the subsidence of the waste is irregular. Since the breaks also occur irregularly, it is not known where the breaks occurred. In addition, even if the top surface of the final soil cover is sloped, the slope itself will change due to subsidence. On the other hand, according to the configuration of the seventh embodiment, the positions where the gaps are formed can be predicted by not integrating the plurality of moisture permeable sheets 13, so that the subsequent measures can be easily and reliably performed. That is, since the moisture permeable sheet 13 only needs to be laid again above the position where the gap is formed, the number of the moisture permeable sheet 13 is small and the construction is easy.

The inclination form of the plurality of moisture permeable sheets 13 whose edges are displaceably superposed is not limited to the substantially V-shaped cross section as in the sixth embodiment, and the seventh embodiment shown in FIG. As in the embodiment, the moisture permeable sheet 13 may be inclined only in one direction. However, even in this case, the lower edge portion of the moisture permeable sheet 13 may be bent upward in order to suppress infiltration of rainwater and the like.

Further, in the sixth and seventh embodiments, the moisture permeable sheet 13 may be replaced with a water impervious sheet made of synthetic rubber or the like which is impermeable to moisture. Also in this case, the same action and effect can be obtained by overlapping the edges of the plurality of water-impervious sheets so that they can be displaced from each other and preventing the water-impervious sheets from tearing. In addition, when the moisture permeable sheet 13 is replaced with a water impermeable sheet, in order to sufficiently evaporate the water in the waste 3,
It is necessary to provide a larger number of evaporation pipes 7 for evaporating water vapor than in the above-mentioned respective embodiments.

Further, in each of the above-mentioned embodiments, the moisture permeable sheet 13 or the water impervious sheet is laid on the soil covers 11, 12 made of earth and sand, but the structure of the soil cover is not limited to this. For example, the moisture permeable sheet 13 or the water impervious sheet may be laid directly on the waste 3, and the moisture permeable sheet 13 or the water impervious sheet itself may be used as the cover soil. In addition, a semipermeable layer formed by insolubilizing a water-soluble polymer is formed on the waste 3 or on the earth and sand layer thinly formed on the waste 3, and the moisture permeable sheet is formed on the semipermeable layer. 13 or a waterproof sheet may be laid to cover the soil. Examples of the water-soluble polymer insolubilized include those obtained by drying or coagulating an aqueous solution of a completely saponified PVA mixed with earth and sand as a filler.

[0052]

According to the first aspect of the present invention, water vapor evaporates but rainwater does not pass on the same day soil cover, intermediate soil cover, or final soil cover covering the dumped waste, or as the soil cover itself. Since a wet sheet is laid, it is possible to prevent rainwater and the like from directly entering the waste disposal site, while moisture in the waste disposal site can be discharged by transpiration, thus reducing the leachate from the waste. It can prevent pollution of the surrounding environment.

According to the invention of claim 2, in addition to the effect of the invention of claim 1, in addition to the final cover soil, on the same day soil cover, intermediate soil cover or at the most last soil cover, or as the soil cover itself, a multi-layer Since a moisture permeable sheet is laid on the floor, leachate from the waste can be reduced even in the middle stage of waste dumping, and leachate after the waste dumping is completed can be further reduced.

According to the invention of claim 3, in addition to the effect of the invention of claim 1 or 2, the edge portions of a plurality of moisture-permeable sheets are superposed in a mutually displaceable manner to prevent tearing of the moisture-permeable sheet. Therefore, as the dumped waste subsides with time, the moisture-permeable sheets do not tear apart and a gap is created between the moisture-permeable sheets, but the position of this gap is clear. It can be easily and surely dealt with by laying it.

According to the invention of claim 4, claims 1 to 3
In addition to the effect of the invention of any one of 1, the evaporation pipe for evaporating water vapor is set up near the ground where waste is dumped. It can be evaporated and the leachate from the waste can be further reduced.

According to the fifth aspect of the present invention, a water impermeable sheet impermeable to water is laid on the same day soil cover, intermediate soil cover, or final soil cover that covers the dumped waste, and vapor vapor is evaporated. Since the evaporation pipe to be started up was set up from the vicinity of the ground where the waste is dumped, penetrating through the impermeable sheet, it is possible to prevent rainwater and the like from directly entering the waste disposal site, while Moisture can be drained by transpiration, thus reducing leachate from waste and preventing pollution of the surrounding environment. In addition, since the edges of multiple water-impervious sheets are superposed so that they can be displaced relative to each other to prevent tearing of the water-impervious sheets, the impermeable sheets do not tear as the dumped waste subsides over time. Although there is a gap between the water-impervious sheets, the position of this gap is clear, so that it is possible to easily and surely deal with it by laying the water-impermeable sheet again.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment (first and second embodiments) of a waste disposal site of the present invention.

FIG. 2 is a cross-sectional view showing an example of construction of the moisture-permeable sheet.

FIG. 3 is a cross-sectional view showing another example of construction of the moisture-permeable sheet of the above.

FIG. 4 is a cross-sectional view of a portion of the above evaporation pipe.

FIG. 5 is a sectional view showing a third embodiment of the waste disposal site of the present invention.

FIG. 6 shows a fourth embodiment of the waste disposal site of the present invention, (a) is a plan view and (b) is a sectional view.

FIG. 7 is a sectional view showing a fifth embodiment of the waste disposal site of the present invention.

FIG. 8 is a plan view showing the arrangement of the water collecting and draining pipes.

FIG. 9 is a sectional view showing a sixth embodiment of the waste disposal site of the present invention.

FIG. 10 is a cross-sectional view showing a state in which the impermeable sheet is re-laid after the waste subsides.

FIG. 11 is a sectional view showing a seventh embodiment of the waste disposal site of the present invention.

[Explanation of symbols]

 1 Ground 3 Waste 7 Evaporation Pipe 11 Same-day soil cover or intermediate soil cover 12 Final soil cover 13 Moisture permeable sheet 42 Soil cover (up to last soil cover)

Claims (5)

[Claims] 1. A moisture permeable sheet that allows water vapor to pass through but does not allow rainwater to pass through is laid on the same day soil cover, intermediate soil cover, or final soil cover that covers the discarded waste. A waste disposal site characterized by preventing water from infiltrating into the waste and evaporating water in the waste to reduce leachate from the waste. 2. The disposal according to claim 1, characterized in that, in addition to the final soil cover, a moisture-permeable sheet is laid on the same day soil cover, intermediate soil cover or at most the last soil cover, or as the soil cover itself in multiple layers. Disposal site. 3. The waste disposal site according to claim 1, wherein the edges of the plurality of moisture permeable sheets are overlapped with each other so as to be displaceable with each other to prevent the moisture permeable sheets from tearing. 4. The waste disposal site according to any one of claims 1 to 3, wherein a vaporization pipe for vaporizing water vapor is set up near the ground where waste is dumped. 5. A transpiration pipe for evaporating water vapor is laid by laying an impermeable sheet impermeable to moisture on the same day soil cover, intermediate soil cover, or final soil cover that covers the discarded waste, and discarding the vaporization pipe. Starting from near the ground where the materials are dumped and penetrating through the impermeable sheet, it prevents rainwater from entering the waste and evaporates the water in the waste to reduce the leachate from the waste. , A waste disposal site characterized in that the edges of a plurality of water-blocking sheets are superposed so that they can be displaced with respect to each other to prevent the water-blocking sheets from tearing.