JP3094748B2 - Waste disposal method and waste disposal site - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste disposal method and a waste disposal site in which water stored in the waste disposal site is prevented from dissipating outside without being treated.

[0002]

2. Description of the Related Art A landfill site using a landfill method uses a valley in a mountain or creates a space for landfill by excavation, and dumps waste into the space for landfill.

[0003] In this type of waste disposal site, there is a problem of groundwater contamination due to heavy metals and the like eluted from incineration ash due to rainwater or the like. As one of the pollution prevention measures, a method has been adopted in which the exuding water is stopped by defining the periphery of the disposal site from the surrounding ground by a water blocking wall or a water blocking film or the like.

[0004]

However, in practice, it is almost impossible to make the water-blocking wall or the water-blocking film a complete water-tight structure, and even if water-tightness is maintained immediately after construction, long-term operation is not possible. It was hard to say that watertightness was maintained. Therefore, even if this kind of water shield works is provided, there is a risk that contaminated water may seep into the surrounding ground as a result.

[0005] Accordingly, the present invention provides a method for discharging water to the outside while actively treating the water without dispersing the internal water to the outside without being treated, even on the premise that the watertightness of the water shielding works is not sufficient. Was examined in various ways.

The present invention has been made in view of the above points, and an object of the present invention is to provide a waste disposal method capable of preventing groundwater contamination of the surrounding ground due to seepage from waste. .

Another object of the present invention is to provide a waste disposal site provided with the above-mentioned pollution control function.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been made to achieve the above-mentioned object, and its gist is to form on the ground.
The water-blocking means, such as a water-blocking wall and a water-blocking film , installed on the bottom of the formed recess, and the water- permeable drainage means installed on the upper surface of the recess, make the space defined by the surrounding ground Dump waste inside
After the landfill is completed, cover the surface with water-blocking means.
In this way, the final disposal site is formed , and the water stored in the space is discharged to the outside through the pumping means and the purification means, and the water level in the space is kept lower than the groundwater level of the surrounding ground.

[0009] Still another aspect of the present invention relates to a method for forming a space for dumping waste in the ground, the bottom of a recess formed in the ground.
And the surface after completion of landfill
Impermeable means for covering the bottom , and impermeable means installed on the bottom of the recess
Of sand or permeable sheets installed on the upper surface of
Aqueous drainage means, water pumping means for pumping water stored in the space, water level control means for controlling the head of the water pumping means to keep the water level in the space lower than the groundwater level of the surrounding ground, Purifying means for purifying water and discharging the water to the outside.

[0010]

According to the above-mentioned waste disposal method, the internal water pressure surrounded by the impermeable means is maintained at a negative pressure as compared with the underground water pressure of the surrounding ground, and the imperfect water impermeable means is imperfect due to the pressure difference. If so, seepage water from the waste that accumulates inside the impermeable means does not leak out. In addition, since the pumped water is discharged to the outside through the purification means, it does not pollute the environment.

In the above-mentioned waste disposal site, it is only necessary to add a pumping unit, a water level control unit, and a purification unit to a conventional disposal site.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a plan view of a waste disposal site 10 according to the present invention, and FIG. 2 is a sectional view taken along line AA of FIG.

This waste disposal site is constructed using a mountain valley shown by the contour line in FIG. 1, and the downstream side of the valley is closed by a water blocking wall 1 such as an underground dam, thereby forming the waste disposal site. At the bottom of the space 2 as a recess having an open upper part, a water shield 3 is constructed along the inclined surface thereof.
And a filter layer 4 (drainage means) of a predetermined thickness is constructed on the upper surface of the water shield 3 and the waste 5 is dumped into the space 2 surrounded by these. Landfill is performed, and the surface protruding to the ground surface after the landfill is completed is covered with the impermeable sheet 6.

Examples of the water stop wall 1 include steel sheet pile, horizontal pile sheet pile, continuous underground wall, earth anchor retaining wall, precast concrete sheet pile, and the like.

The water shield 3 is constituted by a water blocking wall or a water blocking film. In this embodiment, the cost is reduced by using a water blocking film of an asphalt coating, a synthetic fiber sheet, a rubber sheet or the like.

The filter layer 4 is provided to evenly drain water, and can be made of sand, gravure or a water-permeable sheet . At the deepest part of the space 2, a pumping pipe 7 whose tip is located at the filter layer 4 is provided, and the pumping pipe 7 is connected to a pumping device 8 installed on the water stop wall 1.
Connected to The downstream side of the water pumping device 8 is connected to a wastewater treatment facility 9 disposed downstream of the water blocking wall 1 through a discharge pipe 8a, and the water in the space 2 pumped up by the water pumping device 8 is discharged by the wastewater treatment facility 9. After the treatment, the water is discharged to the downstream river k through the drain pipe 9a. From surrounding ground E
Water impermeable installed at the bottom of space 2 as a recess to be defined
Filter layer 4 (drainage means) is installed on the upper surface of construction 3
Is located at the deepest part of the space 2
And the drainage in the space 2 is even and smooth.
To be performed

In the construction planning of the above-mentioned facilities, the capacity of the pumping device 8 and the wastewater treatment facility 9 is determined by examining the condition of the ground by the latest ground survey technology and analyzing the flow of the groundwater level.

The wastewater treatment facility 9 is of a commonly used deep well type. In the wastewater treatment, chemical substances are introduced to coagulate and adsorb harmful substances, and after confirming that they are harmless, are discharged to a river or the like.

The water pumping device 8 is automatically controlled by a water level control unit 10. Water level control unit 1
Numeral 0 indicates the groundwater level WL1 of the surrounding ground E and the groundwater level WL2 of the space 2 based on the data obtained from the surrounding ground E of the disposal site 1 and the pore water pressure gauges 11 and 12 buried in the space 2, respectively. Measurement, and based on this measurement result,
By controlling the lift of the pumping device 8 so that L2 <WL1, the water pressure inside the space 2 is always kept lower than the groundwater pressure.

Therefore, by this control, even if groundwater flows into the space 2 from the surrounding ground E through the water shield 3 even if the water shield of the water shield 3 is not sufficient, Untreated water in the space 2 is prevented from leaking to the surrounding ground E.

There is a concern that the inflow of groundwater may not go according to the theory depending on the state of the ground and the state of the seepage control. However, when the ground E is a ground having high permeability, the inflow of the groundwater is large. There is no need to take any special measures because the pressure difference effect due to the water level difference caused by the internal drainage can be expected.

In addition, during landfill, the surface of the disposal site is open-air, and rainwater flows into the space 2 of the disposal site. However, since the landfill site covers the surface of the disposal site after the landfill is completed, the amount of fluctuation due to rainwater is small, and only the amount of groundwater that enters the space 2 from the surrounding ground E is discharged. In addition, since the groundwater can be expected to decrease due to clogging by groundwater entering from the surroundings, the water level is relatively stable and the driving force can be small, so it can be replaced with a smaller capacity device and the running cost can be reduced. .

In the embodiment, the water blocking film 3 is a water blocking film system having a low initial cost. However, the water blocking wall and the combination of the water blocking wall and the water blocking film are required according to the excavation shape, the scale of the formation, the topography, and the like. Can be variously adopted.

In the above embodiment, the pumping device 8, the wastewater treatment equipment 9, the water level control unit and the auxiliary equipment are arranged from the beginning of the construction of the waste disposal site. Needless to say, the method can also be applied to existing disposal sites that have completed the above.

[0026]

As described in detail in the above embodiments, according to the waste disposal method of the present invention, the internal water pressure surrounded by the impermeable means is maintained at a negative pressure compared to the underground water pressure of the surrounding ground. Even if the impermeable means is incomplete due to the pressure difference, seepage water from the waste accumulated inside the impermeable means does not leak to the outside. Further, since the pumped water is discharged to the outside through the purifying means, environmental pollution can be prevented. In addition, as a recess formed from the ground
Drainage means on the top of the impervious means installed at the bottom of the space
The drainage in the space is evenly and smoothly
To be performed And, the waste disposal method of the present invention,
Since it is a final disposal site, fluctuations due to rainwater are small and
Just discharge the amount of groundwater that enters the space from the surrounding ground
And clogging by groundwater invading from the surroundings
The water level is relatively stable because the groundwater can be expected to decrease.
Also, since the driving force can be small, the device can be smaller.
They can be replaced and running costs can be reduced.

The above-mentioned waste disposal site can be implemented simply by adding a pump, a drainage unit, a water level control unit and a purification unit to a conventional disposal site, and can be easily implemented. The present invention can also be applied to an existing waste disposal site. This has the advantage that the spread of groundwater contamination can be prevented. Also, the waste disposal method according to the present invention
As in the case of the
The drainage in the space is evenly and smoothly performed
Can be replaced with a smaller device.
Also, the cost of the lining can be reduced.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram for landfilling waste in a waste disposal site according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

[Explanation of symbols]

Reference Signs List 1 water blocking wall (water blocking means) 2 space 3 water blocking work (water blocking means) 4 filter layer (drainage means) 5 waste 8 pumping device (pumping means) 9 wastewater treatment facility (purification means) 10 water level control unit ( Water level control means) WL1 Groundwater level around ground WL2 Groundwater level inside space

Continuation of front page (56) References JP-A-4-34120 (JP, A) JP-A-6-304541 (JP, A) JP-A-55-155775 (JP, A) JP-A-3-68485 (JP) , A) JP-A-5-8803 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B09B 1/00 ZAB

Claims (2)

(57) [Claims] 1. The method is carried out at the bottom of a recess formed in the ground.
That cut-off wall, construction of the water shield means and the upper surface of such waterproofing membrane
Dumping waste into the space defined by the surrounding ground by the permeable drainage means ,
The surface is covered with water-blocking means to make it a final disposal site, and the water stored in the space is discharged to the outside through the pumping means and the purification means while the water level in the space is kept lower than the groundwater level of the surrounding ground. Waste disposal method characterized by the above-mentioned. 2. A space for dumping waste is defined in the ground.
To be installed at the bottom of the recess formed in the ground
A water blocking means covering the surface after landfill completion of the space, concave
And gravel on the top of the impermeable means installed at the bottom of the site
Alternatively, a permeable drainage means such as a permeable sheet, a pumping means for pumping water stored in the space, and a water level for controlling the head of the water pumping means so as to keep the water level in the space lower than the groundwater level of the surrounding ground. A waste disposal site, comprising: a control unit; and a purification unit configured to purify pumped water and discharge the water to the outside.