JP5346412B1 - Leachate treatment system - Google Patents

Abstract

The present invention provides a leachate treatment system that can cope with a large amount of leachate generated from a disposal site.
SOLUTION: A leachate treatment system is stored in a disposal site main body 1 which is a reclaimed landfill for embankment material, an adjustment pond 2 for temporarily storing leachate generated in the disposal site main body 1, and an adjustment pond 2. The leachate treatment unit 3 for treating the leachate and the sludge treatment unit 4 for treating the sludge discharged by the leachate treatment unit 3 are provided. The leachate treatment unit 3 is composed of two treatment devices, the first leachate treatment devices 31a to 37a and the second leachate treatment devices 31b to 37b. The sludge treatment unit 4 dehydrates the sludge discharged from the first leachate treatment devices 31a to 37a and the second leachate treatment devices 31b to 37b by the sludge dehydrator 42, and fills the residue with inorganic waste. As landfill.
[Selection] Figure 1

Description

  The present invention relates to a leachate treatment system for treating leachate in a final disposal site where landfill material containing inorganic waste is reclaimed.

  In general, in an open-type final disposal site without a roof, treatment of leachate generated by rainfall becomes a problem. In particular, it is necessary to treat the leachate so that the leachate from rainwater that comes into contact with the waste does not leak into the surrounding environment.

  Therefore, conventionally, as a technique related to the treatment of leachate from waste, it has been known that a water-impervious sheet is provided on the surface of the dumping hole excavated from the waste dumping site to prevent the leachate from leaking to the surrounding ground. (For example, refer to Patent Document 1).

JP-A-6-126265

  However, according to the technique of Patent Document 1, it is assumed that leachate does not flow out of the dumping hole, and it is difficult to treat a large amount of leachate when heavy rain occurs due to weather conditions. There was a problem.

  In view of such circumstances, an object of the present invention is to provide a leachate treatment system that can cope with a large amount of leachate generated from a disposal site.

The leachate treatment system of the first invention is a leachate treatment system for treating leachate in a final disposal site that fills up a fill material containing inorganic waste,
An open-type disposal site main body, which is a landfill for reclaiming the embankment material, and has a bottom wall and a vertical wall that are impermeable to water on the inside,
Only a leachate generated in the disposal site main body flows in, a closed type adjustment pond for temporarily storing the leachate,
A leachate treatment unit for treating leachate stored in the adjustment pond,
The leachate treatment unit
A first leachate treatment apparatus and a second leachate treatment apparatus for treating leachate stored in the adjustment pond in parallel;
A sludge treatment section for dewatering sludge discharged from the first leachate treatment apparatus and the second leachate treatment apparatus,
Residue which is dehydrated by the sludge treatment unit is reclaimed as the fill material with the inorganic waste,
In the disposal site main body, the embankment material is buried as a compacted molded body shield structure,
The compacted body shield structure is:
A unit landfill space for reclaiming the embankment material partitioned by the wall surface is partitioned in the horizontal direction to secure the first space and the second space, and the B type inorganic waste having a harmful substance concentration exceeding a predetermined value in the first space A first compacted part obtained by charging and compacting a B-type embankment material containing
A second compacted part obtained by putting and compacting a Class A embankment material containing Class A inorganic waste having a hazardous substance concentration of a predetermined value or less on the first compacted part;
In the state where the first compacted portion and the second compacted portion are formed, the partition between the first space and the second space is removed, and the A-type embankment material is put into the second space. A third compacted part obtained by compaction;
An upper shield structure of a water-blocking structure formed on top of the second compacted molded part and the third compacted molded part;
A side shield structure having a water shielding structure formed on a side surface of the third compaction portion exposed by removing the wall surface;
It is characterized by providing .

  According to the leachate treatment system of the first invention, rainwater that falls in the disposal site main body flows into the adjustment pond as leachate. At this time, since the adjustment pond is a closed type, there is no inflow of other than leachate, so that the amount of leachate treated can be increased as compared to an open type adjustment pond.

  Moreover, even if there is heavy rain or the like due to weather conditions and the adjustment pond becomes full, the disposal site main body functions as a second adjustment pond because it has a water-impervious treatment structure on its inner surface. Therefore, it is possible to cope with a large amount of leachate generated from the disposal site.

  Further, the leachate stored in the adjustment pond, and when the adjustment pond is full, the leachate in the adjustment pond and the disposal site main body are the first leachate treatment device and the second leachate treatment device as the leachate treatment unit. Are processed by the two processing devices.

  At this time, sludge discharged from the first leachate treatment apparatus and the second leachate treatment apparatus becomes a problem, but the sludge is treated together in one sludge treatment section, and the dehydrated residue is inorganically discarded. It is possible to treat even when a large amount of leachate is generated from the disposal site by filling in the embankment material in the same manner as the material.

  Thus, according to the leachate treatment system of the first invention, it is possible to cope with a case where a large amount of leachate is generated from the disposal site.

Further, according to the leachate treatment system of the first aspect of the invention, the upper shield structure and the side surfaces of the water-impervious structure together, the upper and side surfaces exposed during landfill landfill embankments member including inorganic waste as the compacting body in the disposal site body Use a shield structure. Thereby, the rain water which fell on the disposal site main body can be made to flow on the surface of a compacting body.

  Therefore, it is possible to avoid rainwater coming into contact with inorganic waste and the embankment material containing inorganic waste, it is possible to reduce the soil and sand contained in the leachate, separated from the leachate and leachate The treatment of the sludge can be facilitated, and the treatment amount of the leachate treatment unit can be increased.

Thus, according to the leachate treatment system of the first invention, even when a large amount of leachate is generated from the disposal site, it can be treated.

The whole block diagram of the leachate treatment system of one embodiment of the present invention. Sectional drawing which shows the structure of the disposal site main body of FIG. Explanatory drawing which shows the structure of the leachate treatment part of FIG. Explanatory drawing which shows the landfill division in a final disposal site. The flowchart which shows the process of the manufacturing method of the compacting molded object shield structure of this embodiment. Explanatory drawing which shows the manufacturing method of the compacting molded object shield structure of FIG. Explanatory drawing of each process shown to the flowchart of FIG. Explanatory drawing of each process shown in the flowchart of FIG. 5 following FIG.

  As shown in FIG. 1, a leachate treatment system as an embodiment of the present invention will be described. The leachate treatment system treats leachate at a final disposal site where landfill materials containing inorganic waste are landfilled.

  The leachate treatment system includes a disposal site main body 1 that is a landfill site for embankment, an adjustment pond 2 that temporarily stores leachate generated in the disposal site main body 1, and leachate stored in the adjustment pond 2 A leachate treatment unit 3 to be treated and a sludge treatment unit 4 to treat the sludge discharged from the leachate treatment unit 3 are provided.

  First, the leachate temporarily stored in the pump chamber 10 is introduced into the adjustment pond 2 via the pump P through the pump chamber 10 provided between the disposal site main body 1 and the adjustment pond 2.

  Further, as shown in FIG. 2, the disposal site main body 1 is an open type disposal site having a vertical wall 11 and a bottom wall 12 and having an open upper part. A perforated water collecting pipe 13 is provided on the bottom wall 12, and the water collecting pipe 13 is connected to the pump chamber 10.

  The leachate in the disposal site main body 1 is introduced into the pump chamber 10 through the water collection pipe 13 and, as will be described later, rainwater that has flowed over the surface of the compacted body filled with the embankment material containing inorganic waste is collected. The water is introduced into the pump chamber 10 from the water tank 10a through the introduction pipe 10b.

  A water shielding structure is formed on the inner surfaces of the vertical wall 11 and the bottom wall 12.

  Specifically, the inner surface of the vertical wall 11 has a structure in which a plurality of protective mats 11b that cover and protect the surface of the water-impervious sheet 11a and the water-impervious sheet 11a are laminated as a water-impervious treatment structure. Furthermore, the covering structure 11c which sprayed the nonflammable spray material on the surface of urethane and urethane is formed in the surface.

  Similarly, the inner surface of the bottom wall 12 has a structure in which a plurality of (two in this embodiment) protective mats 12b for covering and protecting the water-impervious sheet 12a and the upper and lower sides thereof are laminated as a water-impervious structure. The crushed stone 12X is laid on the upper side and the lower side of the water-impervious treatment structure, and the above-described water collecting pipe 13 is provided on the upper crushed stone 12X.

  In addition, it is preferable that the water-impervious treatment structure provided on the bottom wall is formed in a plurality of layers. In this embodiment, in addition to the above-described uppermost water-impervious treatment structure, an intermediate layer and lower-layer water-impervious treatment structure (the intermediate-layer and lower-layer water-impervious sheets are composed of one sheet) are provided.

  The adjustment pond 2 is a closed type adjustment pond into which only leachate generated in the disposal site main body 1 flows. In the present embodiment, the adjustment pond 2 is an underground tank capable of storing about 2000 liters.

  The leachate treatment unit 3 is composed of two treatment devices, the first leachate treatment devices 31a to 37a and the second leachate treatment devices 31b to 37b.

  Specifically, as shown in FIG. 3, each of the treatment devices 31 a to 37 a and 31 b to 37 b is first introduced into the raw water adjustment tank 30 by the pump P from the adjustment pond 2 and introduced by the pumps P and P, respectively. And processed as follows.

  First, the leachate is agglomerated by pretreatment tanks 31a and 31b including a reaction tank, a mixing tank, and a coagulation tank, and then introduced into coagulation sedimentation tanks 32a and 32b that precipitate aggregates.

  The leachate from which the aggregates have been removed by the coagulation sedimentation tanks 32a and 32b is introduced into the neutralization tanks 33a and 33b, neutralized, and subsequently biologically treated in the biological treatment tanks 34a and 34b. . And the leachate after biological treatment is filtered in the filtration raw water tanks 35a and 35b.

  Next, radioactive materials and the like are removed from the leachate filtered in the raw filtration water tanks 35a and 35b by the zeolite adsorption towers 36a and 36b and the activated carbon adsorption towers 37a and 37b.

  In this way, the leachate treated in the two systems 31a to 37a and 31b to 37b is introduced into one treatment tank 38 as treated water and then discharged. The treatment tank 38 also has functions as a water inspection tank and a disinfection tank.

  Next, the sludge treatment part 4 processes the sludge discharged | emitted with one system | strain in connection with the above-mentioned treatment of leachate 31a-37a, 31b-37b, and is the sludge storage tank 40 and a sludge coagulation tank. 41 and a sludge dehydrator 42.

  Specifically, sludge and activated sludge removed by the coagulation sedimentation tanks 32a and 32b and the biological treatment tanks 34a and 34b were introduced into the sludge storage tank 40, and these sludges were once stirred in the sludge aggregation tank 41. Above, it is introduced into the sludge dewatering machine 42.

  The filtrate separated by the sludge dehydrator 42 is returned to the adjustment pond 2, and the residue is reused as a material for the compacted body in the same manner as the inorganic waste, as will be described later.

  The above is the overall configuration of the leachate treatment system.

  Next, with reference to FIGS. 4-8, the structure of the compacting body and its shield which are buried in the disposal site main body 1 is demonstrated.

  First, as shown in FIG. 4, in the final disposal site, a section (unit landfill space) in which the embankment material containing inorganic waste is landfilled is defined as a landfill direction X on the same plane and a direction Y perpendicular to the landfill direction X. When all the same planes are landfilled, the next plane is defined in the height direction Z and developed.

  In the present embodiment, a case will be described below in which a compacted body obtained by filling a banking material containing inorganic waste in a section (Xn, Yn) of a layer Zn is shielded.

  As shown in FIG. 6, in the inorganic waste solidified shield structure, first, a section (Xn, Yn) of the layer Zn is partitioned by a wall surface to form a landfill space Wn (unit landfill space), and then the landfill space Wn. Are partitioned in the horizontal direction into a first space I and a second space II (FIG. 5 / STEP 1... Pretreatment step).

  Specifically, in the pretreatment process, as shown in FIG. 4, first, the wall surface of the adjacent sections (Xn, Yn−1) and (Xn−1, Yn) that have already been landfilled, and the temporary dam 1000 are covered with an iron plate 1100. The reclamation space Wn is formed by the wall surface formed by leaning.

  The temporary dam 1000 and the iron plate 1100 are arranged for the landfill direction X side, and the temporary dam 1000 'and the iron plate 1100' are arranged for the direction Y side perpendicular to the landfill direction.

  Next, the internal partition temporary dam 2000 is installed on the landfill direction X side of the landfill space Wn, and the partition iron plate 2100 is leaned on the partition wall 2n, whereby the internal partition temporary dam 2000 is installed in the second. Let it be the space II and the remaining first space I.

  FIG. 7A shows a state in which the landfill space Wn is partitioned into the first space I and the second space II by the partition iron plate 2100 as described above.

  Note that the internal partition temporary dam 2000 has a tapered surface in which the contact surface with the partition iron plate 2100 narrows from the upper side to the lower side.

  Next, before and after the pre-treatment step of STEP 1, materials such as a covering material made of a type A embankment material, a type B embankment material and a cement kneaded material are produced in advance (FIG. 5 / STEP5, material production step). .

  In such a material manufacturing process, a kneading device (not shown) is used to produce a type A embankment material by adding cement and water to a type A inorganic waste that does not contain incinerated ash with a high concentration of harmful substances and kneading the material. Cement and water are added to B type inorganic waste containing incinerated ash with a high concentration and kneaded to produce a B type embankment material. Further, a cement kneaded material (for example, mortar) obtained by adding sand and water to cement and kneading it is manufactured as a coating material.

  In addition, the Class A inorganic waste may be a waste having various harmful substance concentrations that are not more than a predetermined reference value, respectively (regardless of the reference value). It may be a waste having a low concentration.

  In addition, by applying the above-mentioned standard, the residue of the sludge dewatering machine 42 of the sludge treatment unit 4 is also used as a type A or B type material as a type A inorganic waste or a type B inorganic waste.

  Next, the 1st compacting part 100 is formed by throwing B type embankment material into the 1st space I, and compacting (FIG. 5 / STEP10 .. 1st process).

  In such a first step, the first type I is filled with the B-type embankment material, leaving certain upper spaces Ia and Ib in the upper part of the first space I, and the first B-type embankment material is placed and compacted, so that the first The compacted part 100 is formed.

  Next, the second compacted portion 200 is formed by introducing and compacting the A-type embankment material into the upper space Ia above the first compacted portion 100 (FIG. 5 / STEP20, second step).

  In the second step, the type A embankment material is charged into the upper space Ia above the first consolidation section 100 (leaving the upper space Ib), and the charged type A embankment material is placed and compacted. Thus, the second consolidation part 200 is formed.

  In addition, in the second step, before introducing the A-type embankment material, by placing a new crushed stone on the first compacting portion 100 and placing it, the B-type embankment material and It is preferable not to contact the A-type embankment material directly. Moreover, the shielding effect by crushed stone is also exhibited by this when a radioactive substance is contained in B-type embankment material.

  FIG. 7B shows a state in which the first compacted part 100 and the second compacted part 200 are formed in the first space I in this way.

  Next, the partition between the first space I and the second space II is removed, and the A-type embankment material is put into the second space and compacted to form the third compacted portion 300 (FIG. 5 / STEP30). -Third step).

  In the third step, first, the internal partition temporary dam 2000 is suspended and removed, and then the partition iron plate 2100 is removed. At this time, the temporary barrier dam 2000 for the internal partition has a tapered surface in which the contact surface with the partition iron plate 2100 becomes narrower from the upper side to the lower side, so the first compacted part 100 and the second compacted part The high pressure applied to this surface during the compacting of 200 acts to push up the temporary partition dam 2000 for the internal partition. Therefore, the internal partition temporary dam 2000 can be lifted and easily removed.

  Next, leaving the fixed upper space Ib above the second space II, the type A embankment material is thrown in, and the injected type A embankment material is placed and compacted to form the third compacted portion 300. To do. At this time, the A-type embankment material is thrown in and placed in the third compacted portion 300 so that the surface thereof is flush with the second compacted portion 200.

  FIG. 7C shows a state in which the third compacted portion 300 is formed in the second space II in this way.

  Note that a structure in which the first compacted part 100, the second compacted part 200, and the third compacted part 300 are integrated corresponds to the compacted body of the present invention.

  Next, the upper surfaces of the second compacted part 200 and the third compacted part 300 are shielded (FIG. 5 / STEP 40... Fourth step).

  In the fourth step, as shown in a partially enlarged view in FIG. 8A, a new material crushed stone is spread on the second compacted molded part 200 and the third compacted molded part 300 (upper space 1b). The upper primary shield layer 410 is formed by compaction. Next, a covering material (for example, mortar) made of a cement kneaded material manufactured in STEP 5 is spread, and crushed stone is spread on the spread covering material, and the upper capping layer 420 is formed. Further, crushed stone is spread on the upper capping layer 420 to form the upper secondary shield layer 430.

  Next, a laying iron plate (not shown) is laid so as to cover the entire upper surface of the upper secondary shield layer 430, and a weight (not shown) is placed on the laying iron plate to allow the curing period to elapse, thereby allowing the upper primary shield to pass. The layer 410, the upper capping layer 420, and the upper secondary shield layer 430 are integrated. At this time, the surface f is set to be flush with the adjacent section. Then, after the curing period, the iron plate and weight are removed.

  The upper shield structure 400 thus obtained is shown in a partially enlarged view in FIG.

  By forming the upper shield structure 400 in which the three layers of shields 410 to 430 are integrated on the upper surface of the compacted body, contact between the inorganic waste and rainwater is completely avoided on the upper surface of the compacted body.

  Next, the side surface of the third compacted portion 300 exposed by removing the wall surface on the landfill direction X side is shielded (FIG. 5 / STEP 50... Fifth step).

  In the fifth step, first, the temporary dam 1000 on the landfill direction X side is suspended and removed, and then the iron plate 1100 is removed.

  At this time, the temporary dam 1000 ′ and the iron plate 1100 ′ in the direction Y perpendicular to the landfill direction X are maintained until the next landfill start of the next section (Xn, Yn + 1). Thereby, it is possible to prevent the side surface in the direction Y perpendicular to the landfill direction X from being exposed. In addition, although the reclamation of the next section (Xn, Yn + 1) is started in a relatively short time after the reclamation of the current section (Xn, Yn), the section boundary portion by the iron plate 1100 ′ is necessary. Is preferably covered with a vinyl sheet or the like until the next landfill start.

  Next, the side primary shield layer 510 is formed by applying a paint (a highly waterproof exterior paint, such as an epoxy resin undercoat paint) to the exposed side surface of the third compacted molded part 300. Further, the side capping layer 520 is formed by thickly coating the side primary shield layer 510 with a paint (a highly waterproof exterior paint, such as a synthetic resin emulsion-based thickening finish). Further, a side secondary shield layer 530 is formed by applying a paint (a highly waterproof exterior paint such as an epoxy resin top coat) to the side capping layer 520.

  In addition, when there is a concave portion on the side surface of the exposed third consolidation section 300, the side primary shield layer 510, the side capping layer 520, and the side secondary shield layer 530 are formed after the concave portion has been solidified with a covering material in advance. It is preferable to form.

  By forming the side shield structure 500 by the three layers of shields 510 to 530 on the side surface of the compacted body, contact between the inorganic waste and rainwater is completely avoided on the side surface of the compacted body.

  As described above, according to the compacted body shield structure in which the upper shield structure 400 and the side shield structure 500 are formed on the upper surface and the side surface of the compacted body, the upper surface and the side surface of the compacted body are shielded to make inorganic waste and rainwater. Can be avoided. When inorganic waste contained in a compacted body can be completely prevented from leaching into rainwater, and the disposal site itself can function as a second adjustment pond, and a large amount of leachate is generated from the disposal site Can also respond.

DESCRIPTION OF SYMBOLS 1 ... Disposal site main body, 2 ... Regulating pond, 3 ... Leachate treatment part, 4 ... Sludge treatment part, 10 ... Pump room, 11 ... Vertical wall, 12 ... Bottom wall, 11a, 12a ... Water shielding sheet (water shielding treatment) Structure), 11b, 12b ... protection mat (water-impervious treatment structure), 31a-37a ... first leachate treatment apparatus, 31b-37b ... second leachate treatment apparatus, 42 ... sludge dehydrator, 100 ... first compaction molding Part (consolidated compact), 200 ... second compacted compact (consolidated compact), 300 ... third compacted compact (consolidated compact), 400 ... upper shield structure, 410 ... upper primary shield layer, 420 ... upper capping Layer, 430 ... upper secondary shield layer, 500 ... side shield structure, 510 ... side primary shield layer, 520 ... side capping layer, 530 ... side secondary shield layer, 1000 ... temporary dam, 1100 ... iron plate, 2000 ... inside Cut for the temporary dam, 2100 ... partition iron plate, I ... first space, II ... the second space.

Claims (1)

A leachate treatment system for treating leachate in a final disposal site that fills up embankment materials containing inorganic waste,
An open-type disposal site main body, which is a landfill for reclaiming the embankment material, and has a bottom wall and a vertical wall that are impermeable to water on the inside,
Only a leachate generated in the disposal site main body flows in, a closed type adjustment pond for temporarily storing the leachate,
A leachate treatment unit for treating leachate stored in the adjustment pond,
The leachate treatment unit
A first leachate treatment apparatus and a second leachate treatment apparatus for treating leachate stored in the adjustment pond in parallel;
A sludge treatment section for dewatering sludge discharged from the first leachate treatment apparatus and the second leachate treatment apparatus,
Residue which is dehydrated by the sludge treatment unit is reclaimed as the fill material with the inorganic waste,
In the disposal site main body, the embankment material is buried as a compacted molded body shield structure,
The compacted body shield structure is:
A unit landfill space for reclaiming the embankment material partitioned by the wall surface is partitioned in the horizontal direction to secure the first space and the second space, and the B type inorganic waste having a harmful substance concentration exceeding a predetermined value in the first space A first compacted part obtained by charging and compacting a B-type embankment material containing
A second compacted part obtained by putting and compacting a Class A embankment material containing Class A inorganic waste having a hazardous substance concentration of a predetermined value or less on the first compacted part;
In the state where the first compacted portion and the second compacted portion are formed, the partition between the first space and the second space is removed, and the A-type embankment material is put into the second space. A third compacted part obtained by compaction;
An upper shield structure of a water-blocking structure formed on top of the second compacted molded part and the third compacted molded part;
A side shield structure having a water shielding structure formed on a side surface of the third compaction portion exposed by removing the wall surface;
Leachate management system comprising: a.