JP4649657B2 - Waste landfill disposal method and waste landfill structure - Google Patents

Description

  The present invention relates to a waste landfill disposal method and a waste landfill structure.

  Conventionally, when waste is disposed of in landfills, it is possible to expand the aerobic area in the landfill layer of waste from the method of simply dumping the waste into the excavation and valleys of the flat land and covering it as the landfill structure. A method in which the leachate discharged from the leachate collection and drainage pipe disposed at the bottom of the landfill waste layer is returned to the landfill layer through the degassing dredge and the leachate is circulated while providing dredging (For example, refer to Patent Document 1).

  In the former method, the waste layer is highly humid and methane gas is known to be generated by anaerobic bacteria. If this is called an anaerobic landfill structure, the latter is large enough for the leachate collection drainage pipe. Since the opening is in contact with the atmosphere, air is naturally supplied from the leachate collection drainage pipe to the inside of the waste layer, and it is in an aerobic state, so it is called a semi-aerobic landfill structure. Yes.

And this semi-aerobic landfill structure prevents leachate from penetrating into the landfill waste layer, preventing infiltration of leachate into the foundation ground (water-blocking function), and the landfill site by leachate collection drainage pipe By taking air into the interior, leachate can be purified at the stage of collecting water, and the temperature inside the landfill rises due to the heat of fermentation accompanying the microbial decomposition of the waste. Due to the temperature density flow caused by the difference between the two, air (oxygen) is introduced into the landfill through the leachate collection drainage pipe, aerobic decomposition is promoted, and the system is very simple in terms of structure and maintenance. be able to.
JP-A-11-216440

  Compared to the anaerobic landfill structure, the semi-aerobic landfill structure described above can stabilize the landfill quickly and can significantly improve the quality of the leachate. There was still room to devise so that it could be done more efficiently.

  For example, in the current semi-aerobic landfill structure, energy for maintaining it must be introduced from the outside, and an improvement in cost has been desired.

  An object of the present invention is to provide a waste landfill disposal method and a waste landfill structure capable of solving the above-described problems.

In order to solve the above problem, the present invention according to claim 1 to construct a semi-aerobic landfill structure waste landfill sites, until the elapse of the predetermined period to the discharge water of the semi-aerobic landfill structure In addition, the ground surface forming the ventilation part is shielded by a shielding means and maintained as an anaerobic landfill structure period, and then the shielding means is removed according to the release of the shielding of the drainage part to restore the semi-aerobic landfill structure. This is the landfill disposal method.

Further, in the present invention described in claim 2 , in the waste landfill disposal method according to claim 1 , methane gas generated during the anaerobic landfill structure period is recovered and can be used as energy. And

Further, in the present invention described in claim 3, in the waste landfill disposal method according to claim 1 or 2 , when it is determined that the methane gas recovery efficiency during the anaerobic landfill structure period is inappropriate for energy utilization, It is characterized by restoring to an aerobic landfill structure.

Furthermore, in the present invention described in claim 4 , in the waste landfill disposal method according to any one of claims 1 to 3 , the waste landfill disposal site is divided into a plurality of sections, and each section is divided. It is characterized by sequentially restoring from anaerobic landfill structure to semi-aerobic landfill structure.

In the present invention according to claim 5, an anaerobic landfill is provided by providing a detachable shielding part on the ground surface and the drainage part forming the ventilation part constituting a part of the semi-aerobic landfill structure constructed in the waste landfill disposal site. The structure is a waste landfill structure.

(1) In the present invention described in claim 1, it is extremely cost-effective to create a waste landfill that incorporates the advantages of both an anaerobic landfill structure and an aerobic landfill structure to significantly improve the environmental protection function. This can be realized advantageously. In particular, a large amount of leachate can be prevented, and methane gas can be efficiently generated in an anaerobic landfill structure, thereby effectively utilizing the methane gas.

( 2 ) In the present invention according to claim 2 , by collecting methane gas which is an environmental load generated in the anaerobic landfill structure and using it as energy, it can contribute to prevention of global warming and waste landfill. The maintenance cost of the ground can be reduced.

(3) In the present invention of claim 3, wherein, in addition to the effect of claim 1-2, it is possible to determine when anaerobic landfill structural period efficiently.

( 4 ) In the present invention described in claim 4 , in addition to the effects of claims 1 to 3 , for example, leachate from an anaerobic landfill section is circulated to a section that has already been restored to a semi-aerobic landfill structure. Thus, the quality of leachate can be improved efficiently at low cost.

( 5 ) In the present invention according to claim 5 , a semi-aerobic landfill structure in which a shield part is detachably provided on the ground surface and drainage part forming the ventilation part is provided in advance, and initially used as an anaerobic landfill structure. It is possible to recover the methane gas and use it for energy, and then remove the shield and easily restore it to a semi-aerobic landfill structure to stabilize the landfill early while improving the leachate quality. It becomes.

  The waste landfill disposal method according to the present invention constructs a semi-aerobic landfill structure in a waste landfill disposal site, and shields at least the drainage part of the semi-aerobic landfill structure until a predetermined period elapses. It is maintained as a landfill structure period, and then the shielding of the drainage part is released to restore the semi-aerobic landfill structure.

  In other words, in the landfill waste layer of the waste landfill disposal site, a dredging for expanding the aerobic area is provided, and a leachate collection drainage pipe is disposed at the bottom of the landfill waste layer to provide a semi-aerobic landfill. A structure has been built in advance, and the leachate collection drainage pipe that becomes the drainage section is provided with an openable and closable valve so as to be closed to shield the drainage section that constitutes a part of the waste landfill site. First, use it as an anaerobic landfill structure, then open the valve to release the shielding of the vent and drainage and restore it to a semi-aerobic landfill structure to stabilize the landfill early It is a thing.

  In this case, the surface soil layer of the waste landfill disposal site is formed using viscous soil, and in addition to the drainage part of the semi-aerobic landfill structure, the ground surface serving as the ventilation part of the landfill waste layer is shielded as much as possible. It is preferable to be in a state.

  More preferably, the ground surface forming the ventilation portion is shielded by a shielding means such as a cap sheet, and the cap sheet is removed according to the release of the shielding of the drainage portion. When laying a cap sheet as a shielding means, the upper end opening of the ridge is covered with the cap sheet.

  That is, after the initial use as an anaerobic landfill structure, the cap sheet that had been laid is removed, and the valve is opened to release the shielding of the ventilation part and the drainage part, so that a semi-aerobic landfill structure with a high purification action is obtained. It will be restored to stabilize landfills at an early stage.

  As described above, the waste landfill structure according to the present embodiment is anaerobic by providing a removable shielding part in the ventilation part and the drainage part constituting part of the semi-aerobic landfill structure constructed in the waste landfill disposal site. It is a new waste landfill structure that has constructed a landfill structure.

  With such a configuration, it is possible to realize a waste landfill with a significant improvement in the environmental conservation function by incorporating the advantages of the anaerobic landfill structure and the aerobic landfill structure in an extremely advantageous manner in terms of cost.

  Further, during the anaerobic landfill structure period, the generated methane gas can be recovered and used as energy. For example, it can be used as electrical energy for maintenance management of waste landfill disposal. Therefore, since methane gas is not released into the atmosphere, it can contribute to the prevention of global warming.

  And when it is judged that the efficiency of methane gas recovery during such anaerobic landfill structure period is unsuitable for energy use, it can be restored to a semi-aerobic landfill structure. Can be determined.

  When restoring to a semi-aerobic landfill structure, first the shielding of the drainage part is released, and after the leachate collection drainage pipe constituting the drainage part has been purified by air, the shielding of the ventilation part is released. And good. This is because if the cap sheet constituting the shielding structure of the ventilation portion is removed from the beginning, a large amount of unpurified leachate may be generated.

  By the way, when actually constructing a waste landfill site, it is preferable to divide the waste landfill site into a plurality of sections and restore each section sequentially from an anaerobic landfill structure to a semi-aerobic landfill structure.

  In this way, by dividing the waste landfill site into a plurality of sections, for example, the leachate from the section that remains in the anaerobic landfill structure is circulated to the section that has already been restored to the semi-aerobic landfill structure, The quality of leachate can be improved efficiently at low cost. Furthermore, the energy recovered during the period of the anaerobic landfill structure can be used for maintenance and management of the semi-aerobic landfill structure, and the merit in terms of cost is extremely large.

  At this time, in accordance with the rainy season and dry season in the area to be constructed, the area for waste landfill disposal in the rainy season should be a small area, the area for waste landfill disposal in the dry season should be a large area, and It is desirable not to generate excessively.

  Hereinafter, embodiments of the present invention will be described more specifically with reference to the drawings.

  FIG. 1 is a conceptual explanatory diagram in plan view of a waste landfill according to the present embodiment, FIG. 2 is an explanatory diagram in cross-sectional view of the waste landfill, and FIG. 3 is in a vertical cross-sectional view of the waste landfill. 4 and 5 are schematic explanatory diagrams when a semi-aerobic landfill structure constructed in a waste landfill disposal site formed in a plurality of sections in the waste landfill site is used as an anaerobic landfill structure, FIG. 6 and 7 are schematic explanatory views showing a state in which the anaerobic landfill structure is restored to a semi-aerobic landfill structure, and FIG. 8 is an explanatory view showing a basic flow of the waste landfill disposal method according to the present embodiment. .

  As shown in FIGS. 1 to 3, the waste landfill A according to the present embodiment is formed on a basement stratum 1 formed with a gradient. In this embodiment, the waste landfill A is partitioned into a plurality of waste landfills B from the section B1 to the section B8, and from the sections B1 to B8 on the lower side of the sections B1 to B8 An adjustment pond 8 is provided for storing leachate.

  Moreover, in this embodiment, the area of division B2, B4, B6, B8 is about 1/2 with respect to division B1, B3, B5, B7, and it is from each waste landfill disposal site B in the rainy season and the dry season. In order to average the amount of leachate, the sections B1, B3, B5, and B7 are sequentially formed in the dry season and the sections B2, B4, B6, and B8 are formed in the rainy season. Note that the illustrated waste landfill A is conceptual, and of course, depending on the climate of the area where the waste landfill A is actually created, there is a section between the section created in the dry season and the section constructed in the rainy season. The area ratio will be changed.

  Moreover, as shown in FIGS. 4 and 5, the waste landfill structure according to the present embodiment constructed in each waste landfill disposal site B is an extremely simple semi-aerobic landfill structure. A leachate collection / drainage pipe 3 composed of a perforated pipe buried with gritsite 2 is provided at the bottom of the landfill waste layer 4 in the disposal site B so that the leachate can be discharged out of the landfill system as quickly as possible. ing. 5 is a topsoil layer, and 30 is a through hole provided in the leachate collection drain pipe 3.

  In the landfill waste layer 4, a gutter 6 made of a perforated pipe for expanding the aerobic region is erected in communication with the leachate collection / drainage pipe 3. However, initially, since the semi-aerobic landfill structure is used as the anaerobic landfill structure, the cap sheet 7 having air permeability and water permeability as a shielding means is laid on the entire top surface of the topsoil layer 5. That is, the topsoil surface which becomes the ventilation part of the waste landfill site B is shielded from outside air. In addition, a large number of calculi 2 having a diameter of 10 to 20 cm are arranged around the ridge 6 so as to surround the ridge 6. Reference numeral 60 denotes a through hole formed in the flange 6.

  Further, as shown in FIG. 5, a valve mechanism 9 is attached to the leachate collection / drainage pipe 3 extended to the adjustment pond 8 provided on the lower side of the waste landfill A, and this is closed, The leachate collection / drainage pipe 3 that becomes the drainage section of the aerobic landfill structure is in a shielding state.

  As described above, the anaerobic landfill structure is constructed by providing a removable shielding part in the ventilation part and the drainage part constituting the semi-aerobic landfill structure constructed in the waste landfill disposal site B. Become.

  In order to construct the above-mentioned semi-aerobic landfill structure that was initially anaerobic landfill and then reconstructed into a semi-aerobic landfill structure, first a perforated tube with a plurality of through holes formed on the basement layer 1 The leachate collection / drainage pipe 3 is laid, and the leachate collection / drainage pipe 3 is buried with a number of grits 2 having a diameter of 10 to 20 cm to form a waste dumping area. The dredging 6 is attached to the drainage pipe 3 in a communicating state, and the landfill waste layer 4 is formed by repeatedly dumping and covering the waste, and further covering the top layer to cover the topsoil of the waste landfill disposal site B Layer 5 is formed. In the present embodiment, viscous soil is used for the topsoil layer 5 and the landfill waste layer 4 and the atmosphere are shielded in cooperation with the cap sheet 7. However, when laying the cap sheet 7, it is not always necessary to use viscous soil as the topsoil layer 5.

  In this way, a semi-aerobic landfill structure is constructed, and the semi-aerobic landfill structure is shielded by shielding the ventilation part and the drainage part constituting the part of the semi-aerobic landfill structure. Can be used. At this time, the presence of the cap sheet 7 on the ground surface makes it possible to significantly reduce the amount of leachate even in an area where there is a lot of precipitation.

  In addition, in the case of an anaerobic landfill structure, waste is decomposed by anaerobic bacteria and methane gas is generated from the landfill waste layer 4, so that a gas recovery pipe 10 is arranged as shown in order to recover this. Has been established.

  In the present embodiment, the gas recovery pipe 10 is composed of a main pipe 10a and branch pipes 10b branched from the main pipe 10a and inserted into the tub 6, and the branch pipe 10b is inserted into the tub 6. A plurality of through holes (not shown) are formed in the portion.

  Thus, by providing the topsoil layer 5 and the cap sheet 7 and providing the gas recovery pipe 10, the methane gas generated from the landfill waste layer 4 can be removed without performing boring for recovering the methane gas. It can be recovered efficiently. Therefore, methane gas that causes global warming can be recovered without being released to the atmosphere, and the recovered methane gas can be effectively used as medium-grade energy. Furthermore, when methane gas is used as energy, Since methane gas is converted to carbon dioxide during combustion, clean energy can be used without fear of environmental pollution.

  Thereafter, the amount of methane gas recovered gradually decreases, and at the time when it is determined to be unsuitable for use as energy, the cap sheet 7 is removed and the valve mechanism 9 is opened to restore the semi-aerobic landfill structure. . At this time, for example, if the topsoil layer 5 is not cohesive soil, the amount of leachate may increase at once if the cap sheet 7 is removed at one time. It may be performed after the peripheral portion becomes aerobic and a purification function is formed.

  That is, firstly, the leachate collection drainage pipe 3 in the waste landfill disposal site B is unshielded, and then the shield on the surface ventilation portion is unshielded, as shown in FIG. 6 and FIG. It is restored to a semi-aerobic landfill structure.

  Further, in this embodiment, when restoring to the semi-aerobic landfill structure, the gas recovery pipe 10 is removed, and then the connection pipe 61 is added to each ridge 6 to increase the height, and the final covering soil 51 is embanked. . At this time, the tip 61a of the connecting pipe 61 is surely communicated with the atmosphere so as not to be buried in the final covering soil 51.

  The semi-aerobic landfill structure has a smaller load on stabilization of the landfill and improvement of the quality of the leachate and less maintenance costs compared to the anaerobic landfill structure. Moreover, in the present embodiment, the energy required for maintenance can be converted from methane gas collected during the anaerobic landfill structure period as described above, and therefore, a more economical waste landfill disposal method and Become.

  In addition, since the leachate is drained from the leachate collection drainage pipe 3 by opening the valve mechanism 9, in this embodiment, when the semi-aerobic landfill structure is restored, the submersible pump P The leachate is returned to the waste landfill site B to promote purification of the leachate. At this time, methane gas recovered by the above-described anaerobic landfill structure can be used as driving energy for the submersible pump P.

  By the way, as described above, waste landfill disposal is carried out by dividing it into sections (sections B1 to B8) for a certain period (for example, the rainy season and the dry season), so that the energy from the methane gas recovered during the anaerobic landfill structure Can be used sequentially as power for the submersible pump P, etc., and the power used for reducing and purifying the leachate required for the semi-aerobic landfill structure is not introduced from the outside. High landfill disposal method.

  As described above, in the waste landfill disposal method according to the present embodiment, as shown in FIG. 8, (a) a step of constructing a semi-aerobic landfill structure having a structure that can be converted to an anaerobic state; (B) It consists of a waste landfill process, (c) a methane gas recovery process, and (d) a process for restoring to a semi-aerobic state, by incorporating the advantages of anaerobic landfill structure and aerobic landfill structure. Therefore, it is possible to create a waste landfill with significantly improved environmental protection functions.

  The stabilized landfill obtained in this way can be used quickly, and the value as a landfill is also increased. In addition to the construction of parks and schools, more effective land It can be used.

  As described above, according to the present embodiment, the following waste landfill disposal method and waste landfill structure can be realized.

  A semi-aerobic landfill structure is constructed in the waste landfill disposal site B, and at least the drainage section (eg, leaching) of the semi-aerobic landfill structure until a predetermined period (for example, a period in which methane gas recovery is inappropriate) has elapsed. Water collection drainage pipe 3) is shielded (for example, valve mechanism 9 is closed) and maintained as an anaerobic landfill structure period, and then the drainage part is unshielded to restore to a semi-aerobic landfill structure Landfill disposal method.

  In the waste landfill disposal method, in addition to the drainage part of the semi-aerobic landfill structure, the ground surface forming the ventilation part is shielded by a shielding means (for example, cap sheet 7), and the drainage part is unshielded. A waste disposal method for removing the shielding means.

  In the waste landfill disposal method, the waste landfill disposal method in which methane gas generated during the anaerobic landfill structure period is recovered and used as energy.

  In the above-mentioned waste landfill disposal method, when the methane gas recovery efficiency during the anaerobic landfill structure period is determined to be unsuitable for energy utilization, the waste landfill disposal method is restored to a semi-aerobic landfill structure.

  In the above-mentioned waste landfill disposal method, waste landfill disposal site B is divided into a plurality of sections (for example, sections B1 to B8), and each section is sequentially restored from an anaerobic landfill structure to a semi-aerobic landfill structure. Landfill disposal method.

  In the ventilation part (for example, the ground surface of the waste landfill disposal site B) and the drainage part (for example, leachate collection drainage pipe 3) constituting a part of the semi-aerobic landfill structure constructed in the waste landfill disposal site B, Removable shielding part (for example, if the ventilation part is shielded, the topsoil layer 5 of the waste landfill disposal site B is formed of cohesive soil, or if the cap sheet 7 is laid, the drainage part is shielded. Waste landfill structure with an anaerobic landfill structure with a valve mechanism 9) that can be constructed.

  It should be noted that the present invention is not limited to the above-described embodiment, and is included in the present invention even if the design is changed as appropriate without departing from the gist of the claims.

It is a conceptual explanatory drawing by the planar view of the waste landfill which concerns on this embodiment. It is explanatory drawing by the cross-sectional view of the waste landfill. It is explanatory drawing by the longitudinal cross-sectional view of the waste landfill. It is typical explanatory drawing in the case of using the semi-aerobic landfill structure each constructed | assembled in the waste landfill disposal site formed in multiple sections in the said waste landfill as an anaerobic landfill structure. It is the same schematic explanatory drawing. It is typical explanatory drawing of the state which restored the anaerobic landfill structure to the semi-aerobic landfill structure. It is the same schematic explanatory drawing. It is explanatory drawing which shows the basic flow of the landfill disposal method of a waste.

Explanation of symbols

A Waste landfill B Waste landfill 3 Leachate collection drainage pipe 4 Landfill waste layer 6 竪 渠 7 Cap sheet 9 Valve mechanism 10 Gas recovery pipe

Claims (5)

Waste builds a semi-aerobic landfill structure landfill sites, until the elapse of a predetermined time period in addition to the discharge of water of the semi-aerobic landfill structure, anaerobic and shielded by the shielding means the land surface forming a vent A waste landfill disposal method characterized in that it is maintained as a landfill structure period, and then the shield means is removed and restored to a semi-aerobic landfill structure according to the release of shielding of the drainage part. The waste landfill disposal method according to claim 1, wherein methane gas generated during the anaerobic landfill structure period is recovered and made available as energy . The waste landfill disposal method according to claim 1 or 2, wherein when the methane gas recovery efficiency during the anaerobic landfill structure period is determined to be unsuitable for energy use, the wastewater is restored to a semi-aerobic landfill structure. The waste landfill disposal site is divided into a plurality of sections, and each section is restored from an anaerobic landfill structure to a semi-aerobic landfill structure sequentially. Landfill disposal method. An anaerobic landfill structure is constructed by providing a removable shielding part on the ground surface and drainage part that form part of the semi-aerobic landfill structure constructed in the landfill site. Waste landfill structure.

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