JP4114119B2 - Landfill board processing system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a system for treating a landfill board made of an acidic or alkaline landfill material.
[0002]
[Prior art]
When a landfill board is formed using a landfill material, if the landfill material is an acid or alkaline material, there is a possibility that an acidic component or an alkali component flows into the groundwater system together with rainwater.
[0003]
Therefore, when the landfill destination is, for example, an industrial waste disposal site, a drainage structure is provided at the bottom of the impervious work after a water-impervious work is applied to the bottom of the disposal site, and collected in the drainage structure. The leachate is pumped up, neutralized, and then discharged to prevent the leachate from the landfill material from diffusing into the environment.
[0004]
On the other hand, since the site where the landfill work has been completed becomes a valuable land resource, it is desirable to use this land appropriately and effectively.However, in order to use the site, the settlement and strength of the landfill board, the composition of the landfill material, Needless to say, sufficient attention must be paid to such changes, the quality and quantity of leachate from landfills, and changes thereof.
[0005]
[Problems to be solved by the invention]
Here, for example, when coal ash generated from a thermal power plant or the like is a landfill material, highly alkaline leachate is generated as the rainwater permeates. Therefore, after completion of landfill disposal, pumping up from the drainage structure and neutralization discharge work must be continued for a long time until the pH of the leachate clears a predetermined drainage standard, for example, 5.8 to 8.6. However, there has been a problem that the use of the ruins is delayed or the use of the ruins is substantially difficult.
[0006]
The present invention has been made in consideration of the above-described circumstances, and provides a landfill board processing system capable of quickly starting the use of the ruins when alkaline components and acidic components are leached from the landfill board. With the goal.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a landfill board processing system according to the present invention comprises a neutralization solution preparation means for preparing a neutralization solution and a neutralization solution preparation means connected to the neutralization solution preparation means as described in claim 1. A supply means for supplying the sum solution to the landfill material; a collection and drainage means for collecting the neutralized solution that has permeated the landfill material; and a water treatment facility connected to the collection and drainage means. And a discharge pipe laid on a water barrier constructed on the bottom surface of the storage space for the landfill material, and the drainage means is a drainage pit provided near the ground surface of the storage space. In this configuration, the base end of the drain pipe is communicated with the drainage pit, and the landfill material is used as a landfill material to be landed in a waste disposal site .
Further, the landfill board processing system according to the present invention is, as described in claim 2, a neutralization solution preparation means for preparing a neutralization solution, and the neutralization solution preparation means connected to the neutralization solution preparation means. Supply means, collecting and draining means for recovering the neutralized solution that has permeated the landfill material, and water treatment equipment connected to the drainage means, and the supply means for the landfill material A discharge pipe laid on the bottom surface of the storage space, and the drainage means is constituted by a drainage pit provided in the vicinity of the ground surface of the storage space, and a drainage pipe base is formed in the drainage pit. The end is connected, and a water-impervious wall surrounding the storage space is constructed so that groundwater around the water-impervious wall flows around the lower end of the water-impervious wall and flows into the storage space. Set the discharge direction of the neutralized solution in the pipe vertically upward It is obtained by the reclaimed material to be landfilled the landfill material in waste disposal sites.
[0008]
Moreover, the landfill board processing system according to the present invention comprises the neutralization solution preparation means, the supply means, the drainage means, and the water treatment equipment by connecting the water treatment equipment to the neutralization solution preparation means. Then, a circulation system that returns to the neutralization solution preparation means is formed.
[0009]
In the landfill board processing system according to the present invention, the landfill material is coal ash, and the neutralized solution is acid water.
[0013]
In the landfill board processing system according to the present invention, the neutralized solution prepared by the neutralized solution preparing means is supplied to the landfill material through the supplying means.
[0014]
By doing so, the supplied neutralizing solution neutralizes the landfill material while penetrating through the landfill material, so that the landfill material is recovered by the drainage means as leachable water, and the leachate water is treated with water. It is sent to the equipment, and pH treatment is performed in the equipment.
[0015]
Here, the pH-treated water in the water treatment facility may be discharged to a river or the like as it is, but by connecting the water treatment facility to the neutralization solution preparation unit, the neutralization solution preparation unit, If configured to form a circulation system that returns to the neutralization solution preparation means via the supply means, the drainage means, and the water treatment facility, it is possible to circulate and use the water used for the neutralization treatment of the landfill material. This makes it possible to save water itself, as well as eliminating the need for water tanks, water supply pumps, water discharge channels to rivers, etc.
[0016]
As the landfill material, all materials in which alkali components and acidic components are exuded by the action of itself or in the form of being entrained in the infiltrated rainwater with the infiltration of rainwater are targeted. Further, the neutralizing solution may be appropriately selected according to the pH of the landfill material. For example, when the landfill material is coal ash, the neutralization solution may be acid water prepared from dilute hydrochloric acid, dilute sulfuric acid, carbonic acid, or the like.
[0019]
Further, when the supply means is constituted by a discharge pipe laid on the bottom surface of the storage space for the landfill material, and the drainage means is constituted by a collection and drainage pit provided near the ground surface of the storage space. It can also be applied to a waste disposal site that does not have a drainage structure.
[0020]
Further, a water-impervious wall surrounding the storage space is constructed so that groundwater around the water-impervious wall flows into the storage space around the lower end of the water-impervious wall, and the middle of the discharge pipe If the discharge direction of the sum solution is set vertically upward, the neutralizing solution will neutralize the landfill material while reliably infiltrating upward due to the vertically upward discharge action and the upward flow of groundwater. Even without providing a water-impervious structure at the bottom of the storage space, neutralize the landfill board early without worrying about the eluate or neutralized solution from the landfill material penetrating downward and diffusing into the groundwater system It becomes possible.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a landfill board processing system according to the present invention will be described below with reference to the accompanying drawings. Note that components that are substantially the same as those of the prior art are assigned the same reference numerals, and descriptions thereof are omitted.
[0022]
FIG. 1 is an overall view showing a landfill board processing system according to the present embodiment. As can be seen from the figure, the landfill board processing system 1 according to the present embodiment includes a production facility 2 as a neutralization solution production means for producing a neutralization solution, and a discharge as a supply means connected to the production equipment. A pipe 3, a collection / drain pit 4 as a collection / drainage means for collecting the neutralized solution that has permeated the landfill material to become exudate, and a water treatment facility 6 connected to the collection / drainage pit via a drain pipe 5 With.
[0023]
The production facility 2 includes a neutralizer tank 7 in which an acidic solution such as dilute hydrochloric acid, dilute sulfuric acid, and carbonic acid is accommodated as a neutralizer, and a water tank 8 in which water for diluting the neutralizer as necessary is accommodated. And a mixer 9 for mixing and stirring them, and a pump 10 for pumping the mixture and stirring to the discharge pipe 3 as a neutralized solution.
[0024]
Here, a water treatment facility 6 is connected to the mixer 9, and the treated water that has been subjected to pH treatment in the water treatment facility is mixed and stirred together with a neutralizing agent and water to again form the discharge pipe 3 as a new neutralized solution. It is supposed to be pumped to. That is, the production facility 2, the discharge pipe 3, the drainage pit 4 and the water treatment facility 6 form a circulation system related to the neutralized solution.
[0025]
A number of discharge holes 12 for discharging the neutralizing solution are formed in the discharge pipe 3, and are laid on the bottom surface of the storage space 11 for the landfill material. The discharge pipe 3 can be constituted by, for example, a hollow pipe made of vinyl chloride.
[0026]
The drainage pit 4 is installed in the vicinity of the ground surface (landfill top) of the storage space 11 filled with the landfill material after the landfill work of the landfill material is completed.
[0027]
The landfill board processing system 1 according to the present embodiment is assumed to be applied to a waste disposal site that does not have a collection and drainage structure on the bottom surface of the storage space 11. As shown in FIG. 3, the discharge pipe 3 is laid in advance on the water-impervious work 22 constructed on the bottom surface of the storage space 11, and then the landfill work of the coal ash 21 as the landfill material is started.
[0028]
Here, the water-impervious work 22 may be appropriately configured with, for example, reinforced concrete, a waterproof sheet, or the like. The discharge pipe 3 is preferably laid so that the discharge hole 12 faces upward.
[0029]
Next, the landfill work of the coal ash 21 is started. And if the coal ash 21 is reclaimed to the predetermined design height, the drainage pit 4 is constructed near the ground surface (landfill top end), and the base end of the drainage pipe 5 is communicated therewith. A drainage pump 23 is appropriately disposed on the proximal end side of the drainage pipe 5.
[0030]
When the construction of the treatment system 1 is completed in this way, a neutralization solution is produced by the production equipment 2 and supplied to the coal ash 21 that is a landfill material through the discharge pipe 3.
[0031]
In this way, the supplied neutralization solution neutralizes alkaline components such as alkaline earth metals and alkali metal ions such as calcium ions, sodium ions and potassium ions eluted from the coal ash 21 while passing through the coal ash 21. However, after that, it exudes into the drainage pit 4 as exudate.
[0032]
The neutralization solution may be prepared using dilute hydrochloric acid, dilute sulfuric acid, carbonic acid, or the like, but the properties of the coal ash 21 and the like are set so that iron, aluminum, or heavy metals are not eluted from the coal ash due to too strong acidity. It is desirable to adjust the acidity accordingly. It is also conceivable to intermittently supply the neutralizing solution from the discharge pipe 3 while monitoring the pH change of the exudate. In addition, if the acidity of the neutralization solution is adjusted so that the water exuded into the drainage pit 4 is as neutral as possible, the burden of pH treatment in the water treatment facility 6 may be reduced. It becomes possible.
[0033]
Next, the water that has oozed into the drainage pit 4 is sent to the water treatment facility 6 through the drain pipe 5 and subjected to pH treatment as appropriate in the facility.
[0034]
The water treated in the water treatment facility 6 is appropriately mixed with water and a neutralizing agent again in the mixer 9 as described above, and then pumped to the discharge pipe 3 as a new neutralizing solution for circulation use. Is done.
[0035]
As described above, according to the landfill board processing system 1 according to the present embodiment, acidic water that is the supplied neutralization solution is eluted from the coal ash while passing through the coal ash 21 that is the landfill material. Since the alkaline component to be neutralized is neutralized, the landfill board made of coal ash 21 changes quickly from a highly alkaline ground to a neutral ground.
[0036]
Therefore, it becomes possible to start the use of the ruins after the completion of the landfill work earlier than in the conventional case where the neutralization in the landfill board is left to rainwater infiltration.
[0037]
Moreover, according to the landfill board processing system 1 according to the present embodiment, the water treatment facility 6 is connected to the mixer 9 of the production facility 2, whereby the production facility 2, the discharge pipe 3, the drainage pit 4, and the water treatment facility. A circulation system that returns to the production facility 2 through 6 is formed, and the water used for the neutralization treatment of the coal ash 21 can be circulated and used, as well as saving water itself, as well as a water tank and a water supply pump. In addition, it is possible to omit or reduce the size of the water discharge channel to the river.
[0038]
Moreover, according to the landfill board processing system 1 according to the present embodiment, the landfill material is coal ash 21 and the neutralization solution is acid water. Therefore, the landfill board using coal ash generated from the thermal power plant can be quickly It becomes possible to neutralize.
[0039]
Further, according to the landfill board processing system 1 according to the present embodiment, the discharge pipe 3 is laid on the bottom surface of the storage space 11 and the drainage pit 4 is provided in the vicinity of the landfill top end of the coal ash 21. It can also be applied to a waste disposal site that does not have a drainage structure.
[0040]
In the present embodiment, the discharge pipe 3 as the supply means is laid on the bottom surface of the storage space 11 and the drainage pit 4 as the drainage means is provided in the vicinity of the landfill top of the coal ash 21. As shown in FIG. 3, the supply means is composed of a spraying device 31 installed above the storage space of coal ash 21 that is a landfill material, and the drainage means is a bottom surface of the storage space 11. You may comprise the drainage structure 34 which consists of the drainage materials 32, such as the collected drainage pipe 33 installed in the circumference | surroundings, and the circumference | surroundings. According to such a configuration, it becomes possible to use the collection and drainage structure 34 that is already installed in the waste disposal site for monitoring, and it is possible to suppress new capital investment.
[0041]
Further, as shown in FIG. 4, a large number of bottomed perforated pipes 41 as supply means and bottomed perforated pipes 42 as drainage and drainage means are vertically buried in a landfill board made of coal ash 21 so as to face each other. It may be.
[0042]
Further, in the present embodiment, it is assumed that the present invention is applied to a waste disposal site installed in a mountainous area or the like, but of course the location conditions are not limited to the waste disposal site in the first place. Needless to say, it may be applied to landfills constructed along the coast or offshore.
[0043]
Moreover, in this embodiment, in order to prevent the effluent from the landfill material and the neutralized solution from flowing into the groundwater system and diffusing into the environment, the water shielding work 22 is provided around the storage space. If there is no concern as described above depending on the level of the groundwater level or the height of the seawater, such a water shielding work may be omitted.
[0044]
In the modification shown in FIG. 5, a water-impervious wall 51 surrounding the storage space 11 is constructed, and groundwater around the water-impervious wall travels around the storage space 11 as indicated by the arrow at the lower end of the water-impervious wall 51. The discharge pipe 3 is laid on the excavation bottom surface 52 so that the discharge hole 12 faces vertically upward. In addition, since the production equipment 2 and the water treatment equipment 6 are the same as those in the above-described embodiment, the description thereof is omitted.
[0045]
According to such a configuration, the groundwater is allowed to flow through the impermeable wall 51 by setting the pumping speed of the exudate and the pit depth so that the water level in the drainage pit 4 is always lower than the groundwater level around the storage space 11. A flow that flows from the lower end into the storage space 11 and moves upward is formed.
[0046]
Therefore, the neutralization solution neutralizes the coal ash 21 that is the landfill material while surely permeating upward by the synergistic action of the upward groundwater flow and the vertically upward discharge action, and the storage space 11 Even if there is no water-impervious structure at the bottom, the landfill board can be neutralized early without worrying that the effluent from the coal ash 21 or the neutralization solution will permeate downward and diffuse into the groundwater system. Can be realized.
[0047]
【The invention's effect】
As described above, according to the landfill board processing system of the present invention according to claim 1, the landfill board quickly changes from the alkaline ground or the acid ground to the neutral ground. Therefore, it becomes possible to start the use of the ruins after the completion of the landfill work earlier than in the conventional case where the neutralization in the landfill board is left to rainwater infiltration.
[0048]
Further, according to the landfill board processing system of the present invention according to claim 2, water used for the neutralization treatment of the landfill material can be circulated and used, as well as saving water itself, water tank, water supply There is also an effect that a pump, a water discharge channel to a river, etc. can be omitted or reduced in size.
[0049]
Moreover, according to the processing system of the landfill board of this invention which concerns on Claim 3, the effect that it becomes possible to neutralize the landfill board using the coal ash which generate | occur | produces from a thermal power plant quickly is also show | played.
[0050]
In addition, according to the landfill board processing system of the present invention according to claim 4, it is possible to use the collection and drainage structure already installed in the waste disposal site for monitoring, and to suppress new capital investment. There is also an effect.
[0051]
Moreover, according to the landfill board processing system of the present invention according to claim 5, there is also an effect that it can be applied to a waste disposal site having no drainage structure.
[0052]
Moreover, according to the landfill board processing system of the present invention according to claim 6, the eluate and the neutralized solution from the landfill material permeate downwardly into the groundwater system without providing a water shielding structure at the bottom of the storage space. There is also an effect that the landfill board can be neutralized at an early stage without worrying about spreading.
[0053]
[Brief description of the drawings]
FIG. 1 is an overall view showing a landfill board processing system according to an embodiment of the present invention.
FIG. 2 is a sectional view showing the operation of the landfill board processing system according to the present embodiment.
FIG. 3 is a sectional view of a landfill board processing system according to a modification.
FIG. 4 is a sectional view of a landfill board processing system according to another modification.
FIG. 5 is a cross-sectional view of a landfill board processing system according to another modification.
[Explanation of symbols]
1 Landfill board treatment system 2 Production equipment (neutralization solution production means)
3 Discharge pipe (supply means)
4 Drainage pit (collection and drainage means)
6 Water treatment equipment 11 Storage space 12 Discharge hole 21 Coal ash (landfill material)
31 Spraying device (supplying means)
34 Collection and drainage structure (collection and drainage means)
41 Bottomed porous tube (supply means)
42 Bottomed perforated pipe (collection and drainage means)
51 Impermeable wall

Claims (4)

Neutralization solution preparation means for preparing a neutralization solution, supply means connected to the neutralization solution preparation means for supplying the neutralization solution to the landfill material, and collection and drainage for recovering the neutralization solution permeating the landfill material And a water treatment facility connected to the water collecting and draining means, and the supply means is composed of a discharge pipe laid on a water barrier constructed on the bottom surface of the storage space for the landfill material. In addition, the drainage means is constituted by a drainage pit provided near the ground surface of the storage space, the base end of the drainage pipe is communicated with the drainage pit, and the landfill material is disposed of as waste. A landfill disposal system characterized by the use of landfill material that is reclaimed on the ground. Neutralization solution preparation means for preparing a neutralization solution, supply means connected to the neutralization solution preparation means for supplying the neutralization solution to the landfill material, and collection and drainage for recovering the neutralization solution permeating the landfill material And a water treatment facility connected to the water collecting and draining means, the supply means is constituted by a discharge pipe laid on the bottom surface of the storage space for the landfill material, and the water collecting and draining means, The drainage pit provided in the vicinity of the ground surface of the storage space, the base end of the drainage pipe communicated with the drainage pit, and a water shielding wall surrounding the storage space is constructed. The groundwater around the bottom of the impermeable wall flows into the storage space, and the discharge direction of the neutralizing solution in the discharge pipe is set vertically upward, and the landfill material is discarded. and characterized in that a landfill material to be buried in things disposal sites Processing system of that landfill ground.   By connecting the water treatment equipment to the neutralization solution preparation means, a circulation system that returns to the neutralization solution preparation means through the neutralization solution preparation means, the supply means, the drainage means, and the water treatment equipment. The landfill board processing system according to claim 1 or 2 configured to be formed.   The landfill board processing system according to claim 1 or 2, wherein the landfill material is coal ash and the neutralization solution is acid water.

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