JP4744499B2 - Waste landfill method and leachate treatment method - Google Patents

Description

  The present invention relates to a waste landfill method and a leachate treatment method, and in particular, significantly reduces the work period and cost for installing a water treatment facility for purifying leachate generated by waste stabilization treatment. The present invention relates to a waste landfill method and leachate treatment method that enable early landfill.

  Industrial waste and general waste are classified into stable waste and managed waste according to the form of landfill disposal.

  Stable waste is stable in shape, such as rubble and earthenware waste, and does not elute harmful components, but managed waste is sludge, wood waste, incinerated ash, etc. It is a waste that discharges harmful elution components that easily cause water pollution.

  For this reason, conventionally, when management-type waste or stable-type waste is landfilled in a disposal site, as shown in FIG. 5, the landfill area is divided into a management-type waste area A and a stable-type waste area B. The area around the waste area A was isolated by a revetment wall as shown in FIG. 6, and a construction method was adopted to prevent the discharge of harmful substances to the outside. In the stable waste area B, there is no fear of the leakage of harmful components, and therefore no revetment wall as shown in FIG. 6 is required.

  The details of the revetment wall will be described with reference to FIG. 6. The revetment wall 200 is installed on the foundation discarding stone 200 a at a portion in contact with the sea. On the managed waste area A side, a sandproof sheet 201, a lining soil 202, a water shielding sheet 203, an intermediate protective layer 204, a water shielding sheet 205, an upper covering layer 206, and a scour prevention sheet 207 are formed in this order. Yes.

  Therefore, conventionally, in the disposal of managed waste, a method has been adopted to purify and stabilize leachate so that water from which toxic substances have dissolved is not leaked to others. There was a problem that a huge cost was required just by installing a revetment wall.

In addition, in order to stabilize the management-type waste on the above-mentioned management-type waste area A side, as shown in FIG. 7, first, the management-type waste I is received and stabilized by watering, and stabilized. If it is, the management-type waste II is accepted and the stabilization process is performed by watering. After stabilization, the management-type waste III is further received and the stabilization process is performed by watering. Such a method has a disadvantage that the stabilization process is not completed until the managed waste III is stabilized, and it takes many years to close. Further, there is a risk of leakage of harmful substances due to rainwater, but there is a problem that enormous costs are required to shield the entire upper part of the managed waste area A.
Japanese Patent No. 3439636 Japanese Patent No. 3876596

  Patent Document 1 describes a method in which managed waste is sprinkled in a plurality of compartments to perform cleaning of harmful substances, and when the waste is stabilized, it is directly landfilled. The technique of patent document 1 implements stabilization of leachate at an early stage by watering in a plurality of sections, and aims at shortening the closing period.

  Although there is no description about caisson in this patent document 1, even if caisson is applied to each compartment, managed waste is accepted in all compartments, and when stabilization processing is completed, each caisson is reclaimed to be closed. It will be.

  However, such a method of closing the caisson itself requires a large amount of caisson according to the amount of managed waste when receiving a large amount of managed waste and stabilizing and landfilling it. There is a disadvantage that should not be.

  Moreover, in order to purify the leachate discharged when stabilizing managed waste, it is necessary to install a water treatment facility. However, as in Patent Document 2, a caisson is used for the water treatment facility. In other words, there is a drawback that the waste stabilization process using the caisson cannot be realized and the original waste landfill process cannot be realized.

  Therefore, the present inventors have caisson ensured the waste stabilization treatment, and the leachate treatment can be disposed of at low cost by using a barge equipped with a water treatment facility, and the water treatment The present inventors have found that the construction period and cost required for installation of facilities can be greatly reduced, and the present invention has been completed.

  That is, the object of the present invention is to divide a landfill area with a caisson, stabilize the waste in the caisson, and then sequentially transfer and landfill to reduce the need for a conventional revetment wall. The object is to provide a landfill method for waste that can be disposed of at a low cost.

  In addition, another object of the present invention is to significantly reduce the construction period and cost for installing a water treatment facility for purifying leachate generated by the stabilization treatment of waste, and enable early implementation of landfill. The object is to provide a method for treating leachate.

  Other problems of the present invention will become apparent from the following description.

  The above problems are solved by the following inventions.

(Claim 1)
In the landfill method of waste that landfills industrial waste or general waste on the coast,
The landfill area of the coast is partitioned by a revetment wall using caisson at least in part, and a barge equipped with a water treatment facility is towed and settled in the landfill area,
Accept waste that discharges harmful elution components in the caisson, stabilize the waste by performing sprinkling treatment with seawater in the caisson,
Purify leachate containing organic matter and harmful elution components generated by the stabilization treatment only at the water treatment facility,
A waste landfill method, wherein the stabilized waste is taken out from the caisson and transferred into the landfill area for landfill.

(Claim 2)
The waste landfill method according to claim 1, wherein a movable roof-like cover is provided above the caisson that receives the waste to block the external environment from the caisson.

(Claim 3)
The landfill area of the coast is partitioned by a revetment wall using caisson at least in part, and a barge equipped with a water treatment facility is towed and settled in the landfill area,
Accept waste that discharges harmful elution components in the caisson, stabilize the waste by performing sprinkling treatment with seawater in the caisson,
A method for treating leachate, comprising purifying leachate containing organic matter and harmful elution components generated by the stabilization treatment only at the water treatment facility.

(Claim 4)
The said water treatment plant | facility has at least the biological treatment equipment which processes the organic matter and nitrogen content in leachate, and the coagulation sedimentation treatment equipment which coagulates and precipitates the harmful elution component in leachate. Treatment method of leachate.

  According to the waste landfill method of the present invention, the landfill area is divided by caisson, and after stabilizing the waste in the caisson, it is transferred and landfilled sequentially, so that a conventional revetment wall is required. In addition, waste can be disposed of at low cost.

  In addition, according to the leachate treatment method of the present invention, it is possible to greatly reduce the construction period and cost required for the installation of a water treatment facility for purifying leachate generated by the stabilization treatment of waste, and the early landfill Enable implementation.

  Further, according to the present invention, waste can be received from the time when the first caisson is installed among the plurality of caissons for partitioning the landfill area. A method can be provided.

  Furthermore, according to the present invention, since there is abundant seawater on the shore, there is abundant water used for watering for stabilization, and water can be used for stabilization, until it stabilizes. It is possible to provide a waste landfill method that can shorten the period of the waste.

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

  FIG. 1 is a plan view showing one embodiment of a waste landfill method and leachate treatment method according to the present invention, wherein 1 is a waste landfill area partitioned into fixed sections from the coast toward the sea. It is.

  In general, there are two types of waste: stable waste that does not elute harmful components and can be landfilled as it is, and managed waste that contains hazardous substances and requires leachate treatment. Unless otherwise specified, in this specification, the latter managed waste is indicated.

  The area around the landfill area 1 is divided by a revetment wall. Here, a plurality of caissons 2 are used as a revetment wall to divide the surrounding area of the landfill area 1. However, the caisson 2 may be installed in at least a part of the revetment wall and may not be shown as the caisson 2. A revetment wall may be configured by combining with a sheet pile.

  In the present invention, a caisson is a box-like form in which a space is formed that can receive waste and can be sprinkled, and is formed in advance in a factory or the like and then brought into the field. .

  The caisson in the present invention may be made of concrete, steel plate, composite structure of steel plate and concrete, etc., and has durability that can be used as a revetment wall, and a weight that can form a revetment wall by its own weight when immersed in seawater. It is preferable.

  Each of the caissons 2 may have a structure (partition) in which the interior is partitioned into a plurality.

  As shown in FIG. 2, the caisson 2 is towed to a planned installation location in the landfill section 1 by using a tug boat or the like (FIG. 2A). The foundation ground 1a is built on the sea floor of the planned installation place as needed, and the caisson 2 is set on the foundation ground 1a by throwing earth and sand 3 etc. into the inner bottom of the caisson 2 (FIG. 2 ( B)). Between the caisson 2 and the coast that has been laid, earth and stones 1b and the like are inserted and buried so that the coast and the caisson 2 are connected to the land (FIG. 2C).

  Further, the barge 4 preloaded with the water treatment facility 5 is towed into the landfill area 1 by a tugboat or the like (FIG. 2D). A foundation ground 1 c is built on the seabed at the place where the barge 4 is to be installed, if necessary, and the barge 4 is grounded on the foundation ground 1 c so as to be close to the caisson 2.

  In addition, a waste stabilization treatment facility 6 described later is installed in at least one of the plurality of caissons 2 (FIG. 2E). After the barge 4 reaches the bottom, the periphery of the landfill area 1 is further divided using a caisson 2 or a sheet pile.

  The barge 4 equipped with the water treatment facility 5 is not limited to one, and as shown in FIG. 1, the barge 41 equipped with the water treatment facility 51 and the water treatment facility 52 according to the scale and the processing amount of the water treatment facility 5. There may be a plurality of units such as a barge 42 equipped with In the case where a plurality of barges 4 are used, each water treatment facility 5 to be mounted can divide a series of water treatment steps and distribute the facilities to the plurality of barges 4.

  In the caisson 2 constituting the revetment wall thus installed, waste that discharges harmful elution components is accepted.

  In the present embodiment, since the caisson 2 is installed as caisson 21 to 26 on one side of the landfill area 1 as well, if these are used for receiving waste, Easy to accept.

  When the waste is transported by sea, the caisson 2 installed on the sea side can be used as the caisson 2 for receiving waste.

  When receiving the waste using the caissons 21 to 26, the charging starts from the caisson 21 near the water treatment facility 51 mounted on the barge 41, for example. In the case of having a plurality of caissons 2 as in this embodiment, when the caisson 21 reaches a predetermined amount as the amount of waste received increases, the caissons 22 may be sequentially inserted in the order of caissons 22, 23. it can.

  The waste thrown into the caisson 2 is subjected to stabilization processing (sprinkling treatment with seawater) in the caisson 2 by the stabilization processing equipment 6.

  FIG. 3 is a schematic diagram illustrating a state in which the waste stabilization process is performed. In FIG. 3, 61 is a seawater pump, and the seawater pumped up by the seawater pump 61 is sent to the sprinkler 63 through the pipe 62. For example, a spray nozzle is installed in the water sprinkling part 63 and sprinkles water from the upper part of the waste 100 thrown into the caisson 2.

  A space 64 is formed in the lower part of the stabilization processing facility 6. The space portion 64 may be formed by installing a through-hole member 65 such as a net or a punching metal at a predetermined height. It is also preferable to provide a non-woven fabric 66 that can pass seawater at the top of the through-hole member 65.

  In the seawater sprinkled from the upper part of the waste 100, soluble organic substances, salts, heavy metals, etc. contained in the waste 100 are eluted as harmful components. If this elution process is continued for a long time, the toxic components are hardly eluted and the waste 100 is stabilized.

  Conventionally, it took several years to completely elute harmful components, but in the case of the present invention, since it is sprinkling with seawater, abundant seawater can be sprinkled quantitatively. It is preferable to supply the amount of water spray quantitatively in order to shorten the stabilization time. Furthermore, since fresh seawater can always be supplied, it is possible to supply minerals to microorganisms that contribute to stabilization in the waste 100, and since seawater is not circulated, accumulation of salt can be prevented.

  Such watering treatment is preferably started when the waste 100 reaches about 20% of the caisson capacity.

  The interior of the caisson 2 above the through-hole member 65 in the stabilization processing facility 6 is partitioned by a partition wall 67, and a water intake pipe 68 for taking out leachate (sewage) accumulated in the space 64 is disposed. , Extending outside the caisson 2. The sewage in the caisson 2 is taken out of the caisson 2 by the discharge pump 69 through the intake pipe 68 and sent to the water treatment facility 5 on the barge 4 to be purified. The sewage sent to the water treatment facility 5 is preferably inspected for water quality at all times or regularly.

  The configuration of the water treatment facility 5 is not particularly limited, but generally, sewage is purified to a degree that meets environmental standards through pretreatment, biological treatment, advanced treatment, and disinfection. After the purification process, the wastewater is drained outside the landfill area 1.

  As the pretreatment means, means for treating oil, contaminants, mud, etc. in the leachate is adopted. For example, the oil can be separated by a flocculant or by an oil / water separator. Contaminants, mud and the like are separated by solid-liquid separation means, but it is more effective to perform a flocculation separation treatment with an inorganic flocculant such as iron chloride or aluminum sulfate.

  In addition, the pretreatment means includes a treatment facility for treating harmful components such as heavy metals contained in the leachate. For the treatment of heavy metals, a coagulation sedimentation treatment or the like can be adopted.

  As the biological treatment means, normal activated sludge treatment equipment, nitrification denitrification treatment equipment, etc. can be adopted. In the present invention, it is preferable to adopt a technique for carrying such biological treatment equipment in a barge and bringing it to the site, in which case microorganisms necessary for biological treatment can be acclimatized before being transported on site, Even if leachate is discharged by stabilization treatment, it can be handled immediately. Therefore, the effect which does not disturb the stabilization process of a waste is exhibited.

  For example, in a biological treatment facility, the stability of treatment cannot be ensured unless the volume load is suitable for the treatment of organic matter. Therefore, it is necessary to secure such volume load, and there is a special contrivance for the installation of aeration pipes. is necessary. In the present invention, since the processing equipment is mounted on the barge and brought to the site, such an aeration tank structure can be designed, manufactured, and tested before being transported, and processing equipment that actually functions can be installed.

  As the advanced treatment means, a technique of subjecting the suspended suspended matter (SS) after biological treatment to coagulation sedimentation treatment or activated carbon treatment can be employed. A film treatment or the like can also be suitably employed.

  By the way, it is not preferable to temporarily spray a large amount of water such as rainwater on the waste 100 in the caisson 2 in order to shorten the stabilization time. Therefore, it is preferable to provide a movable roof-like cover 7 above the caisson 2 where the waste 100 is received, as shown in FIG. The reason is to cover the caisson 2 performing the watering treatment and shorten the stabilization time.

  The cover 7 can be configured to be movable along a direction indicated by an arrow by placing the cover 7 on two rails 8 and 8 laid on the upper surface of the caisson 2, for example. Further, the cover 7 is configured to be stretchable along its moving direction, folded and stored when the waste 100 is thrown in, etc., and extended when necessary in the rain or the like. This is preferable because the installation space can be reduced.

  The waste stabilized in the caisson 2 is taken out from the caisson 2 and sequentially transferred into the landfill area 1 for landfill. The means used for taking out and transferring the waste after the treatment is not particularly limited, and a bucket conveyor or the like (not shown) can be used.

  In the landfill area 1, stable waste that does not require stabilization treatment can be landfilled. When the landfill in the landfill area 1 reaches a predetermined amount and the acceptance of the waste is completed, the stabilization treatment facility 6 is dismantled and concrete is placed inside the caisson 2. Further, the landfill area 1 is covered with the covering soil and the landfill is completed (closed). The barge 4 can be landfilled as it is after the water treatment facility 5 is dismantled and removed.

  According to the present invention, since the waste is stabilized in the caisson 2, it is possible to dispose of the waste at a low cost without requiring a conventional revetment wall. In addition, the water treatment facility 5 for purifying leachate generated by the waste stabilization process may be installed in advance on the barge 4 and towed to the landfill area 1, so that the facility is installed. It is not necessary to secure sufficient space, and the construction period and cost for installing the facilities can be greatly reduced, and land reclamation can be carried out at an early stage.

  In addition, it is possible to accept waste from the time when the barge 4 equipped with at least one caisson 2 and the water treatment facility 5 is installed in the landfill area 1, and there is an effect that the period until the start of treatment is short.

  In addition, since the coast has abundant seawater, there is abundant water used for watering for stabilization, so that water can be used abundantly for stabilization, and the time to stabilization can be shortened. is there.

The top view which shows the one aspect | mode of the landfill method of the waste which concerns on this invention (A)-(E) is explanatory drawing explaining a mode that a caisson and a water treatment facility are installed. Schematic diagram showing how to stabilize waste Perspective view showing mobile cover Plan view showing a conventional example FIG. 5 is a cross-sectional view of an essential part taken along line VI-VI in FIG. Cross-sectional view of the main part showing a conventional example

Explanation of symbols

1: Landfill area 1a: foundation ground 1b: earth and stone 1c: foundation ground 2, 21-26: caisson 3: earth and sand 4, 41, 42: barge 5, 51, 52: water treatment facility 6: stabilization treatment facility 61: seawater Pump 62: Piping 63: Sprinkling part 64: Space part 65: Perforated member 66: Non-woven fabric 67: Partition plate 68: Intake pipe 69: Discharge pump 7: Cover 8: Rail 200: Revetment 200a: Foundation waste stone 201: Sand protection sheet 202 : Seated soil 203: Water shielding sheet 204: Intermediate protective layer 205: Water shielding sheet 206: Upper coating layer 207: Scouring prevention sheet I: Management-type waste (first time input)
II: Managed waste (second time input)
III: Managed waste (third time input)

Claims (4)

In the landfill method of waste that landfills industrial waste or general waste on the coast,
The landfill area of the coast is partitioned by a revetment wall using caisson at least in part, and a barge equipped with a water treatment facility is towed and settled in the landfill area,
Accept waste that discharges harmful elution components in the caisson, stabilize the waste by performing sprinkling treatment with seawater in the caisson,
Purify leachate containing organic matter and harmful elution components generated by the stabilization treatment only at the water treatment facility,
A waste landfill method, wherein the stabilized waste is taken out from the caisson and transferred into the landfill area for landfill.   The waste landfill method according to claim 1, wherein a movable roof-like cover is provided above the caisson that receives the waste to block the external environment from the caisson. The landfill area of the coast is partitioned by a revetment wall using caisson at least in part, and a barge equipped with a water treatment facility is towed and settled in the landfill area,
Accept waste that discharges harmful elution components in the caisson, stabilize the waste by performing sprinkling treatment with seawater in the caisson,
A method for treating leachate, comprising purifying leachate containing organic matter and harmful elution components generated by the stabilization treatment only at the water treatment facility.   The said water treatment plant | facility has at least the biological treatment equipment which processes the organic matter and nitrogen content in leachate, and the coagulation sedimentation treatment equipment which coagulates and precipitates the harmful elution component in leachate. Treatment method of leachate.

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