JP3118771B2 - Waste treatment method and degassing impermeable sheet - 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 employed in a waste disposal site and the like, and a gas venting and water shielding sheet used in the method.

[0002]

2. Description of the Related Art One of the waste disposal methods is a landfill treatment method, which employs a sandwich construction method in which embankment is carried out with a cover soil of about 50 cm every about 3 m in thickness of a waste layer.

[0003]

However, in the conventional method as described above, since the embankment is carried out by directly covering the waste layer, rainwater caused by rainfall forms a permeation storage state in the waste layer to improve air permeability. Inhibits and decomposes by anaerobic bacteria to generate foul-smelling gas and harmful components, and harmful substances from wastes dissolve into rainwater, causing gas ignition and foul odor during and after landfill. In addition, environmental problems such as soil pollution, groundwater pollution, and water pollution occur, and there is a disadvantage that a long period of time is required to use the land even after the completion of the landfill.

Although it is preferable to use an aerobic bacterium for the waste treatment as described above, it is preferable to obtain the treatment, but the aerobic bacterium and the anaerobic bacterium have a characteristic of mutually excluding each other. However, once an anaerobic bacterium has been generated, it is difficult to obtain the action of the aerobic bacterium until the anaerobic bacterium has been completely killed. Therefore, the waste embedded as described above is effective. To be digested for at least a few years,
In some cases, a long time of several tens of years or more is required.

[0005] As described above, environmental pollution is inevitable due to generation of odorous gas and harmful substances by anaerobic bacteria.
Waste treatment must be at least sufficiently isolated from the residential area, and once landfilled, its use is limited for such a long period. If used without such a long digestive period, an odor or the like is generated, and the environment is impaired.

[0006]

SUMMARY OF THE INVENTION The present invention has been studied in order to solve the problems of the conventional method as described above, and has succeeded in realizing an advantageous waste treatment by employing a specific sheet. Then, it has the following configuration.

[0007] In a waste landfill, an air supply pipe provided with a vent hole in the lowermost layer is installed, the air supply pipe is covered with a gas-permeable sheet, and an appropriate amount of water is placed on the sheet. A waste layer of waste is formed, a gas release liner sheet is coated on the waste layer to form an uppermost layer appropriately embanked, and air is supplied to the lowermost layer through the air supply pipe. A waste disposal method characterized by supplying.

[0008] The gas-permeable water-blocking sheet as described above, wherein a waterproof or air-permeable sheet made of a porous film having a protective layer partially adhered to at least one surface is used for one part or the whole surface.

[0009] The degassing and impermeable sheet according to the above, wherein the porous film is a stretched porous film of polytetrafluoroethylene.

The porous film is a polyolefin-based film,
The degassing and impermeable sheet according to the above, which is any of a polyurethane-based, polyester-based, polyether-based, polyvinyl chloride-based, and cellulose-based.

[0011]

The porous film having a protective cloth partially adhered to at least one surface is made of a gas permeable sheet and a gas-permeable waterproof sheet.
By adopting a water-impervious sheet by adopting it on a part or the entire surface, the sheet can be handled as one body and used with appropriate strength in a porous film formed as a relatively thin layer.

[0012] The gas venting and impermeable sheet prevents rainwater from entering the waste layer, and prevents harmful substances in the waste from dissolving in the rainwater and contaminating the soil.

[0013] The water-blocking sheet maintains the air permeability condition in the waste, and prevents rainwater from penetrating into the waste and causing the waste to be decomposed by anaerobic bacteria, thereby generating odor and gas. And promote digestion by aerobic bacteria.

[0014] As described above, the digestion by the aerobic bacteria is appropriately achieved by maintaining the air permeability of the waste layer and supplying the air from the air pipe.

The supplied air, gas generated from the waste, and water vapor (such as those originally contained in the waste and water adhering to rainfall during the disposal work) are released to the atmosphere through a gas release and impermeable sheet. Released inside.

The air-permeable waterproof sheet formed between the air supply pipe and the waste layer prevents moisture from the upper part from penetrating into the vicinity of the air supply pipe and impairing the air permeability of the air supply pipe. The gas is appropriately dispersed and supplied into the waste layer.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention as described above will be described below with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view of a main portion showing a landfill state of the waste landfill method according to the present invention, and FIG. 2 is a cross-sectional view of a porous film portion of a degassing and impermeable sheet.
Is a gas release sheet, 3 and 3 are embankment layers, 4 is a vent pipe, 5 is a blower, 6 is a porous film, 7 is a protective cloth a, 8 is a protective cloth b, and 12 is a gas permeable shield. Each shows a water sheet.

The air appropriately sent from the blower 5 or the like is supplied to the lowermost ventilation pipe 4, and is supplied to the waste layer 1 from the ventilation holes provided on the side surface thereof. The supplied air permeates through the waste layer 1, supplies air to the aerobic bacteria, promotes the decomposition and digestion of the waste, and reaches the gas release / waterproof sheet 2. Since the gas venting / waterproof sheet 2 has waterproof and breathable properties, the blown air also passes through the gas venting / waterproof sheet 2 and is released into the atmosphere.

The supply of air through the air supply pipe 4 is carried out at appropriate time intervals. For this reason, the air blower 5 is intermittently operated and pressurized, and a part or all of the air supply pipe opened to the ground is provided. Thus, air can be supplied by atmospheric pressure.

It is clear that the treatment according to the present invention can be carried out while the air supply pipe 4 and the respective sheets 2 and 12 are permanently buried, but according to the present invention, the vigorous propagation of aerobic bacteria is possible. Therefore, the digestion treatment of the waste can be realized in a relatively short time, so that the air supply pipe 4 and the respective sheets 2 and 12 can be dug out and reused after the digestion treatment. When not reused, the air supply pipe 4 and each sheet material 2, 1
It is preferable to use a light-weight material as 2, and if possible, a material that is digested in the same manner as the waste is digested. If it is to be reused, a material having a certain level of durability is used.

Examples of the porous film used for the gas release and impermeable sheet 2 include porous polyolefin and porous polyurethane, and more preferred in the present invention is expanded porous polytetrafluoroethylene. As the protective cloths 7 and 8 of the porous film, an organic or inorganic fabric, a nonwoven fabric, a net, or the like having high permeability and high strength can be adopted.

The bonding between the porous film and the protective cloth is performed by partial bonding since the air permeability (moisture permeability) is impaired by the bonding portion. The above-mentioned stretched porous polytetrafluoroethylene film can achieve the above-mentioned purpose with a very thin film material because a uniform and fine porous structure can be obtained by stretching. Since it is a layer material, it is very easily damaged, so it is preferable to provide a protective cloth on both sides.

Although it is desirable to use a waterproof and air-permeable porous film for the entire surface of the gas release and impermeable sheet 2, it is necessary to estimate the amount of generated gas and water vapor when the cost is high. It is possible to calculate the moisture permeability and air permeability and the area of the gas venting and impermeable sheet. Therefore, it is necessary to appropriately adopt a partial range of 5 to 80%, preferably 20 to 60% of the total area of the gas venting and impermeable sheet. By doing so, the cost can be kept low.

In the case where a porous film is used as a part of the degassing and impermeable sheet as described above, it is preferable to use a non-permeable or permeable resin film or sheet as the remaining part.

The porous film 6 used for the water-shielding sheets 2 and 12 has a maximum pore diameter of 0.05 to 3 μm.
m, preferably 0.2-1 μm and a porosity of 40-95.
%, Preferably 75-90%, thickness is 10-100μ
m, especially about 30 to 80 μm is suitable.

As the gas-permeable water-blocking sheet 12 located below the waste material layer 1, the same gas-permeable water-blocking sheet 2 as described above is used in principle. It is essential that the air supplied from the air supply pipe 4 is sufficiently dispersed to supply the waste layer 1 with air. To this end, infiltration of water and the like around the air supply pipe is avoided as much as possible, and the air supply is further reduced to the waste layer. 1 is set so that it can be effectively distributed and supplied.

Further, according to the present invention, the embankment layers above and below the waste layer 1 or the breathable impermeable sheet 12
For example, an appropriate amount of a tree, a fibrous material, or the like is mixed to ensure air permeability and an air supply effect in those portions, thereby forming favorable conditions for the growth of aerobic bacteria. It is preferable that such a tree or fibrous material is digested together with the digestion of the waste layer, but in some cases, it may be taken out after treatment and used repeatedly.

[0029]

According to the present invention as described above, in the waste landfill method, rainwater can be completely prevented from infiltrating into the waste layer, so that harmful components in the waste are dissolved. In addition, since it is difficult for water to stay in the waste, anaerobic decomposition is suppressed, and gas generation due to the anaerobic decomposition can be prevented. Furthermore, the aerobic decomposition of organic matter in the waste is promoted, and the gas and water vapor generated from the waste can be released at an early stage. It has a great effect such as realizing.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing a state of a landfill method according to the present invention.

FIG. 2 is a cross-sectional view of a main part of the gas venting and impermeable sheet of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Waste layer 2 Gas release water barrier sheet 3 Embankment layer 4 Ventilation pipe 5 Ventilator 6 Porous film 7 Protective layer a 8 Protective layer b 12 Breathable waterproof sheet

Claims (4)

(57) [Claims] At a waste landfill site, an air supply pipe provided with a ventilation hole in the lowermost layer is installed, and the air supply pipe is covered with a gas-permeable water-blocking sheet. Form a waste layer by the amount of waste, form a top layer that is appropriately embanked on the waste layer by covering with a gas release and impermeable sheet, and via the air supply pipe to the above-described bottom layer part A waste disposal method characterized by supplying air. 2. A gas-permeable and water-permeable sheet used in claim 1, wherein a waterproof or air-permeable sheet made of a porous film having a protective layer partially adhered to at least one surface is used for one part or the whole surface. 3. The gas venting and impermeable sheet according to claim 2, wherein the porous film is a stretched porous film of polytetrafluoroethylene. 4. The degassing water-blocking sheet according to claim 2, wherein the porous film is any of polyolefin, polyurethane, polyester, polyether, polyvinyl chloride, and cellulose.