JP3879563B2 - Waste landfill site, gas collecting device and gas processing device there - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a waste landfill treatment site for landfilling waste, and a gas collecting device and a gas treatment device there.
[0002]
[Prior art]
In the landfill site, methane and carbon dioxide, as well as gas containing hydrogen sulfide, methyl sulfide, methyl disulfide, methyl mercaptan, ammonia, etc. are generated from the layer of waste input. In addition, there are problems such as environmental pollution around the landfill, fire, and environmental destruction due to the emission of greenhouse gases in a broad sense.
[0003]
[Problems to be solved by the invention]
For this reason, most of the existing disposal sites have a degassing pipe with a leachate collection and distribution pipe installed at the bottom of the recessed part constructed by digging down the ground, the upper end opened to the atmosphere, and the peripheral wall has a gas distribution port. A semi-aerobic landfill structure is adopted in many landfills, where the lower end communicates with the above collection and distribution pipes, and air naturally flows into the waste layer that generates gas under anaerobic conditions. Depending on the nature of the waste to be landfilled, the response cannot be made in time, and the problem of gas has not been solved. In addition, in order to positively handle the generated gas, a gas processing device or a new vent well has been installed above all the existing vent pipes. Cost and time.
[0004]
[Means for Solving the Problems]
The present invention was developed in order to solve the above-mentioned problems, and the waste landfill disposal site according to claim 1 lays a leachate collection and distribution pipe at the bottom, and communicates the lower end with the collection and distribution pipe. A gas vent pipe having an upper end opened to the atmosphere and having a gas circulation port on the peripheral wall is erected from the water collection / distribution pipe, gas suction means communicating with the water collection / distribution pipe of the leachate is provided, and the gas sucked by the gas suction means is provided. The gas processing means to process is attached. In this case, it is preferable to provide an air inflow amount adjusting means in the vicinity of the upper end of the degassing pipe, or to provide a shielding means for blocking the gas circulation port on the peripheral wall of the degassing pipe in contact with the atmosphere. The gas collection device in the waste landfill site according to claim 4 is constructed such that a leachate collection / distribution pipe laid at the bottom of the waste landfill disposal site, the lower end communicating with the collection / distribution pipe, and the upper end is the atmosphere In the gas collection device at the waste landfill disposal site provided with a gas vent pipe having a gas circulation port in the peripheral wall, gas suction means communicating with the leachate collection and distribution pipe is provided. . Further, the gas processing apparatus in the waste disposal site according to claim 7 is erected with a leachate collecting / distributing pipe laid at the bottom of the waste landfill disposal site, and a lower end communicating with the collecting / distributing pipe. A gas treatment apparatus in a waste landfill site, comprising a gas vent pipe having a gas circulation port in the peripheral wall and a gas suction means communicating with a leachate collection and distribution pipe, the gas suction means The gas sucked in is supplied to the gas processing means. The gas collecting device at the waste disposal site according to claim 4 and the gas processing device at the waste disposal site according to claim 7 are provided with an air inflow amount adjusting means in the vicinity of the upper end of the gas vent pipe. In addition, it is preferable to provide a shielding means for blocking the gas circulation port on the peripheral wall of the portion of the gas vent pipe that is in contact with the atmosphere.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
In the embodiment shown in the figure, 10 is a vast waste landfill disposal site constructed as a concave part by deeply digging the ground, and its inner periphery and bottom are well known as leachate generated in the concave part. It is covered with an impervious sheet to prevent penetration and contamination of groundwater. In addition, a collection and distribution pipe 11 for draining leachate generated from the discarded waste into a storage tank 12 outside the field is provided like a mesh at the bottom of the recess. In the portion of the water collection and distribution pipe 11 that is piped in the recessed recess, a water inlet for taking in leachate into the pipe is provided in the peripheral wall.
[0006]
Degassing pipes 13 whose lower ends are in communication with the water collection and distribution pipes are erected at places where the pipes are provided in the recessed portions of the water collection and distribution pipes 11. The upper end of the degassing pipe 13 is opened, and the peripheral wall has a gas distribution port for taking in the gas generated from the waste A dumped in the recessed portion. When the height of the waste layer dumped in the concave portion approaches the upper end of the degassing pipe 13, a new degassing pipe is connected and extended upward, and the upper end is always located above the upper surface of the waste layer. Let
[0007]
The leachate collected in the storage tank 12 is sent to the leachate treatment facility by the pump P ₁ , detoxified and discharged.
[0008]
Further, one end of the air supply pipe 14 is opened in the gas phase portion of the storage tank 12. The air supply pipe 14 is provided with a fan F as gas suction means, and the other end of the air supply pipe 14 communicates with the gas processing means 15. The gas generated in the landfill waste layer thrown into the concave portion of the disposal site by the operation of the fan F enters the gas vent pipe 13 through the gas distribution port on the peripheral wall and flows downward to collect and distribute leachate. The water pipe 11 is led to the storage tank 12 and sent to the gas processing means 15 through the air supply pipe 14 where it is processed.
[0009]
The gas treatment in the gas treatment means 15 may be a general gas treatment, for example, water washing, alkali washing, acid washing, alkali + sodium hypochlorite washing, acid washing + alkali washing, acid washing + (alkali + secondary). Sodium chlorite washing), activated carbon adsorption, biological deodorization (including blowing into water aeration tanks), desulfurization tower, etc., selected according to the properties of the generated gas. This gas treatment may be performed in a batch at the leachate treatment plant.
[0010]
Since all the upper ends of the degassing pipes are open to the atmosphere, it is preferable to provide equipment capable of adjusting the degree of opening of dampers or the like to the openings of all the degassing pipes to control the inflow of air. This is because air and generated gas are efficiently sucked from all vent pipes, and landfill waste is kept in anaerobic rather than anaerobic conditions, promoting decomposition and generating hydrogen sulfide and the like by anaerobic fermentation. It is for suppressing. Therefore, the damper 16 or the like is adjusted so that a slight amount of air is sucked from all the gas vent pipes. In addition, you may provide a flow meter in each degassing pipe | tube. If it can do in this way, it is desirable that the oxygen concentration in each connection point of a degassing pipe and a collection and distribution pipe is 15% or more.
[0011]
A gas vent pipe having a gas circulation port on the peripheral wall is used. However, a cover 17 is applied to a portion protruding from the landfill waste layer near the opening, and the gas circulation port on the side of the gas vent pipe is temporarily provided. Shielding is desirable for efficient gas suction. In addition, water collection and distribution pipes that normally have a water inlet on the peripheral wall are used, but even if waste is not piled on the water collection and distribution pipes at the bottom of the recessed parts at the initial stage of reclamation, temporary shielding is performed for the same reason. It is desirable. However, these shields are removed immediately before they are buried by landfills so as not to interfere with the original functions of the gas vent pipes and collection and distribution pipes.
[0012]
In particular, as described above, since the gas vent pipe is extended upward as the bulk of the landfill is increased, the air flow rate adjusting equipment such as the gas distribution port shield and the damper can be easily installed and removed. It is desirable to do so.
[0013]
In the embodiment of FIG. 1, the leachate storage tank 12 has a sealed structure to prevent gas from leaking out of the storage tank, but the upper surface of the storage tank is open as in the embodiment of FIG. Also good. In this case, the end 11 'of the collecting and distributing pipe for introducing the leachate into the storage tank is immersed in the leachate in the storage tank to prevent the gas from coming out of the storage tank, and the The gas to be sucked in can be supplied to the gas processing means 15 from the air supply pipe 14 connected to the collection and distribution pipe.
[0014]
The waste landfill disposal site has been explained by taking the earth as an example, but it may be constructed by creating a valley between mountains, or by forming a soil dam wall and a concrete side wall on a flat ground. May be. The present invention can be applied to an existing disposal site and a new disposal site.
[0015]
【The invention's effect】
According to the present invention, gas containing malodorous, flammable, toxic and global warming substances generated from a waste landfill site is sucked by a gas suction means such as a fan from the end of a water collection and distribution pipe connected to a gas vent pipe. By performing the treatment with the gas treatment means, it is possible to effectively improve the environment without diffusing the generated gas to the periphery. Furthermore, since gas treatment is performed at one point of the collection end point of the collection and distribution pipe (drainage reservoir entrance), it is more efficient than a method in which a treatment device is installed in all the degassing pipes or a degassing well is installed. At the same time, if a gas problem becomes apparent after the operation of the landfill site, the expansion is easy.
[Brief description of the drawings]
FIG. 1 is a flow sheet of an embodiment of a waste landfill site according to the present invention, a gas collection device thereof, and a gas treatment device.
FIG. 2 is a flow sheet of another embodiment of a waste landfill site according to the present invention, and its gas collection device and gas processing device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Waste landfill disposal site 11 Leachate collection and distribution pipe 12 Leachate storage tank 13 Degassing pipe 14 Air supply pipe 15 Gas treatment means 16 Damper 17 Cover for shielding

Claims (9)

A leachate collection / distribution pipe is laid at the bottom of the waste landfill site, and the lower end communicates with the collection / distribution pipe. A waste landfill disposal site characterized in that it is provided with gas suction means communicating with the collection and distribution pipe of the leachate, and gas treatment means for treating the gas sucked by the gas suction means. 2. The waste landfill site according to claim 1, wherein an air inflow rate adjusting means is provided in the vicinity of the upper end portion of the gas vent pipe. The waste landfill site according to any one of claims 1 and 2, wherein a shielding means for blocking a gas distribution port is provided on a peripheral wall of a portion of the vent pipe that is in contact with the atmosphere. Landfill site. A leachate collection / distribution pipe laid at the bottom of the waste landfill site, and a degassing pipe standing at the lower end in communication with the collection / distribution pipe and having an upper end opened to the atmosphere and a gas distribution port on the peripheral wall. A gas collecting apparatus in a waste landfill disposal site, comprising a gas suction means connected to the leachate collection and distribution pipe in the gas collection device in a waste landfill disposal site. 5. The gas collection apparatus for a waste landfill according to claim 4, wherein means for adjusting the amount of inflow of air is provided near the upper end of the gas vent pipe. apparatus. 6. A gas collecting apparatus in a waste landfill site according to any one of claims 4 and 5, wherein a shielding means for blocking a gas distribution port is provided on a peripheral wall of a portion of the degassing pipe that comes into contact with the atmosphere. A gas collection device at a waste landfill site. A leachate collection / distribution pipe laid at the bottom of the waste landfill site, a degassing pipe having a lower end communicating with the collection / distribution pipe and having an upper end opened to the atmosphere and a gas distribution port on the peripheral wall; A gas treatment device at a waste landfill site comprising a gas suction means communicating with a leachate collecting and distributing pipe, wherein the gas sucked by the gas suction means is supplied to the gas treatment means. Gas treatment equipment at a waste landfill site. 8. A gas processing apparatus at a waste landfill site according to claim 7, wherein an air inflow rate adjusting means is provided in the vicinity of the upper end of the gas vent pipe. apparatus. 9. A gas processing apparatus in a waste landfill site according to claim 7, wherein a shielding means for blocking a gas circulation port is provided on a peripheral wall of a portion of the degassing pipe contacting the atmosphere. Gas treatment equipment at a waste landfill site.

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