JP5273608B2 - Leachate treatment method and leachate treatment facility at waste disposal site - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To treat organic substances in leachate with a simple structure without using an advanced biological treatment method such as an activated sludge method, a contact aeration method, a rotary disc method, a carrier method, and a membrane separation activated sludge method. <P>SOLUTION: Leachate treatment equipment includes a stone-piled filter bed 1 composed of a filter medium where aerobic biofilm is generated on its surface, a water sprinkling pipe 2 for sprinkling the leachate onto the stone-piled filter bed 1, and a water-impermeable portion 4 formed under the stone-piled filter bed 1. The aerobic biofilm is generated on the surface of the filter medium by sprinkling the leachate onto the stone-piled filter bed 1, and the organic substances in the leachate are decomposed by the aerobic biofilm to purify the leachate. The leachate having passed through the stone-piled filter bed 1 to be purified is blocked in the lower part of the stone-piled filer bed 1 by the water-impermeable portion 4, and collected and discharged outside the stone-piled filter bed 1. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a leachate treatment method and leachate treatment facility in a waste disposal site for treating organic matter in leachate generated from a waste layer in a waste disposal site.

  Organic matter (mainly BOD (biochemical oxygen demand) component) in leachate generated from the waste layer buried in the landfill site is activated sludge method, contact aeration method, rotating disk method, carrier method And advanced biological treatment methods such as membrane separation activated sludge method. In these biological treatment methods, air is blown into an aeration tank in which leachate and biological floc are mixed and agitated to generate biological floc consisting of sewage organisms, and organic matter is adsorbed and decomposed into the biological floc. Finally, a method of purifying water quality by precipitating biological flocs in a sedimentation tank is common.

  However, these advanced biological treatment methods are expensive to construct and expensive to maintain such as inspection and maintenance of consumables such as drugs and equipment. In addition, these advanced biological treatment methods require management with advanced expertise for operation. Therefore, for example, Patent Document 1 proposes a method of returning leachate generated from a waste final disposal site to a circulation channel and evaporating in the circulation channel in order to reduce the amount of leachate treated. Further, in this method, crushed stone is arranged at the bottom of the circulation channel and the final disposal site of the waste, and the leachate is purified by microorganisms attached to the crushed stone.

  Further, in Patent Document 2, in order to promote the evaporation of leachate, the surface portion of the landfill waste layer is provided with an osmosis pad for temporarily storing the leachate and penetrating the landfill waste layer. A leachate collection / drainage channel that collects and drains leachate is also provided in the deep layer of the leachate, and the leachate drained from the leachate collection / drainage channel is circulated to the seepage trough via the ring channel. A waste landfill system for circulating leachate has been proposed.

  Patent Document 3 discloses that the leachate discharged from the waste is sprinkled with water, and the leachate extracted from the waste is treated with leachate such as biological treatment, coagulation sedimentation treatment, sand filtration and activated carbon adsorption. A method has been proposed in which harmful substances in leachate are removed, treated water from which organic substances have been removed is circulated and returned to the waste.

JP 2007-50326 A Japanese Patent Laid-Open No. 2002-254048 Japanese Patent Laid-Open No. 10-5714

  The methods described in Patent Documents 1 to 3 are all for reducing the amount of leachate treated, but the latter stage is provided with leachate treatment equipment for executing the advanced biological treatment method as described above. ing. Therefore, although these methods can reduce the operation cost, they still require management by highly specialized techniques for operation.

  Particularly in developing countries, advanced biological treatment methods such as those mentioned above are not popular due to high construction costs, and leachate is in a state of running down, and there is no waste final disposal site without leachate treatment facilities. Many. In developing countries, it is difficult to secure human resources possessing advanced technology for the maintenance of leachate treatment facilities, and there are problems such as further increase in maintenance costs.

  Therefore, in the present invention, when treating the organic matter in the leachate generated from the waste layer at the waste disposal site, the activated sludge method, the contact aeration method, the rotating disc method, the carrier method, the membrane separation activated sludge method, etc. An object of the present invention is to provide a leachate treatment method and leachate treatment facility for a waste disposal site capable of treating organic matter in leachate with a simple configuration without using an advanced biological treatment method.

  A leachate treatment method for a waste disposal site according to the present invention is a leachate treatment method for treating leachate generated from a waste layer at a waste disposal site, from an aerobic biofilm generated on a surface. The method includes spraying leachate on the filter bed, intercepting the lower part of the filter bed, collecting the water that has passed through the filter bed, and draining it out of the filter bed.

  According to the leachate treatment method for a waste disposal site of the present invention, an aerobic biofilm is generated on the filter medium surface by spraying leachate on a filter bed made of a filter medium on which an aerobic biofilm is generated. The organic matter in the leachate is adsorbed and decomposed (oxidative decomposition) by the aerobic biofilm, and the leachate is purified. The leachate purified after passing through the filter bed is blocked at the lower part of the filter bed, collected, and drained outside the filter bed.

  Here, when the filter bed is formed by stacking filter media in the air, air (oxygen) is supplied to the inside of the filter bed by natural ventilation, and oxidative decomposition by aerobic microorganisms is actively performed. . Further, when the filter bed is piled up in a state where the ground is dug, an air pipe or the like can be arranged so that air can be easily supplied to the inside of the filter bed. Alternatively, it is possible to forcibly ventilate (forced aeration) the lower part of the filter bed.

  In particular, the leachate treatment method for a waste disposal site of the present invention is suitable for an existing waste disposal site. In this case, it is desirable that the filter bed is disposed on the upper surface of the waste layer, and the leachate is collected by the leachate adjustment equipment, pumped up from the leachate treatment equipment onto the filter bed and sprayed. . As a result, in the existing waste disposal site, leachate generated from the waste layer is stored in the leachate adjustment facility, pumped up to the filter bed above the waste layer and sprinkled, and the leachate is purified on the waste layer. Is done. Note that the filter bed can be disposed on the lower layer side of the waste layer, and in this case, it is not necessary to pump the leachate up to the waste layer.

  A leachate treatment facility for a waste disposal site according to the present invention is a leachate treatment facility for treating leachate generated from a waste layer in a waste disposal site, from a filter medium on which an aerobic biofilm is generated. A filter bed, a watering device for spraying leachate onto the filter bed, and a water shielding part formed at the lower part of the filter bed.

  In the leachate treatment facility of the waste disposal site of the present invention, the leachate is sprinkled on the filter bed made of the filter medium on which the aerobic biofilm is generated, so that the aerobic biofilm is generated on the filter medium surface, This aerobic biofilm adsorbs and decomposes organic matter in the leachate and purifies the leachate. And the leachate purified by passing through the inside of the filter bed is blocked by the water blocking section at the lower part of the filter bed, collected, and drained outside the filter bed.

  In addition, the leachate treatment facility of the waste disposal site of the present invention further includes a leachate adjustment facility for accumulating leachate generated from the waste layer, and the water shielding portion is formed on the upper surface of the waste layer. It is desirable that the watering device is provided with a pump for pumping the leachate from the leachate adjustment equipment onto the filter bed. As a result, leachate generated from the waste layer at the existing waste disposal site is stored in the leachate adjustment facility, pumped up to the filter bed on the upper surface of the waste layer, and sprinkled, and the leachate is purified on the waste layer. The

  Furthermore, the leachate treatment facility of the waste disposal site of the present invention may be provided with a water collection and drainage device that collects water that has passed through the filter bed on the water shielding part and drains it outside the filter bed. desirable. As a result, the leachate that has been purified by spraying the leachate over the filter bed and bringing it into contact with many filter media is collected on the impermeable section and drained outside the filter bed, thereby efficiently purifying the leachate. It becomes possible to do.

  Moreover, it is desirable that the leachate treatment facility of the waste disposal site of the present invention has a ventilation part for venting to the lower part of the filter bed. Thereby, air becomes easy to be supplied to the inside of the filter bed, and oxidative decomposition by the aerobic biofilm is actively performed.

(1) The leachate is sprinkled on the filter bed made of the filter medium on which the aerobic biofilm is formed, and the lower part of the filter bed is shielded to collect the water that has passed through the filter bed. Due to the configuration of draining to the outside of the floor, an aerobic biofilm is generated on the surface of the filter medium, and organic substances in the leachate are adsorbed and decomposed by the aerobic biofilm, and the leachate is purified. This makes it possible to treat organic matter in leachate with a simple configuration without using advanced biological treatment methods such as the activated sludge method, contact aeration method, rotating disk method, carrier method and membrane separation activated sludge method. It becomes.

(2) In particular, the filter bed is placed on the upper surface of the waste layer with water shielding, and the leachate is collected by the leachate adjustment equipment and pumped from the leachate treatment equipment onto the filter bed and sprinkled. Thus, it can be applied to an existing waste disposal site, and a useless space on the upper surface of the waste layer can be effectively utilized.

(3) It has a leachate adjustment facility that collects leachate generated from the waste layer, and the water shielding part is formed on the upper surface of the waste layer, and the water sprinkler is a leachate adjustment facility for the leachate. By providing a pump for pumping up to the filter bed, the leachate generated from the waste layer at the existing waste disposal site is stored in the leachate adjustment facility and pumped up to the filter bed above the waste layer. Water is sprayed and the leachate is purified on the waste layer.

(4) Leached water purified by bringing water that has passed through the filter bed onto the water shielding part and draining it out of the filter bed by spraying the leachate over the filter bed and bringing it into contact with many filter media By collecting water on the water shielding part and draining it out of the filter bed, it becomes possible to efficiently purify the leachate and improve the treatment efficiency of the leachate.

(5) The structure having the ventilation part that ventilates the lower part of the filter bed makes it easy to supply air to the inside of the filter bed, actively oxidatively decomposes by aerobic microorganisms, and improves the leachate treatment efficiency.

(6) When the filter bed is formed by stacking the filter media in the air, air is supplied to the inside of the filter bed by natural ventilation, which is energy saving and active oxidative degradation by aerobic microorganisms. To be done. Further, when the filter bed is piled up in a state where the ground is dug, a ventilation pipe or the like can be arranged so that air can be easily supplied to the inside of the filter bed. Alternatively, it is possible to forcibly ventilate the lower part of the filter bed and forcibly take in fresh outside air, so that oxidative decomposition is more actively performed. At this time, forced ventilation is performed by using natural energy such as sunlight and wind power, thereby saving energy.

  1 is a plan view of a leachate treatment facility in a waste disposal site according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is a cross-sectional view taken along line BB in FIG.

  1 to 3, the leachate treatment facility according to the embodiment of the present invention includes a masonry filter bed 1 and a waste layer R on a waste layer R in which waste from an existing waste final disposal site is buried. A sprinkling pipe 2 for sprinkling leachate generated from the water and a treated water tank 3 are installed. In the lower part of the masonry filter bed 1, there is formed a water shielding part 4 composed of a water shielding sheet, viscous soil, watertight asphalt, bentonite sheet, and the like.

  Further, at the lower part of the masonry filter bed 1, a collection and drainage device that collects water that has passed through the masonry filter bed 1 on the water shielding part 4 and drains it to the treated water tank 3 outside the masonry filter bed 1. A drain pipe 5 is provided. The diameter of the drainage pipe 5 is, for example, about 400 to 1000 mm. The body of the drainage pipe 5 is provided with a plurality of water collection ports (not shown). The water-impervious portion 4 is formed with an inclined surface so that the central portion where the drainage pipe 5 is provided is lowered, and the water passing through the masonry filter bed 1 is collected on the water-impervious portion 4. Collected into the collection / drainage pipe 5 from a plurality of collection ports and drained into the treated water tank 3.

  In addition, a leachate adjustment pond 6 as leachate adjustment equipment is provided on the lower layer side of the waste layer R. In the leachate adjustment pond 6, leachate generated from the waste layer R is temporarily stored.

  The masonry filter bed 1 is formed by stacking stones such as crushed stones and chestnuts as filter media in the air after forming the water shielding portion 4 on the waste layer R. The diameter of these stones is, for example, about 200 to 300 mm. In these stones, an aerobic biofilm is generated on the surface by sprinkling of leachate from the sprinkling pipe 2. By this aerobic biofilm, organic substances in the leachate are adsorbed and decomposed (oxidative decomposition). Note that the masonry filter bed 1 may be a filter medium in which an aerobic biofilm is generated on the surface by sprinkling of leachate, and may be formed of a plastic lump or a concrete lump.

  The sprinkling pipe 2 constitutes a sprinkling device together with the submersible pump 7 installed in the leachate adjustment reservoir 6 and the submersible pump 8 installed in the treatment water tank 3. As shown in FIG. 1, a plurality of masonry filter beds 1, water spray pipes 2, treated water tanks 3, water shielding parts 4, and drainage pipes 5 are arranged in parallel on the waste layer R.

  In the leachate treatment facility having the above-described configuration, the leachate in the leachate adjustment pond 6 is pumped above the waste layer R by the submersible pump 7 and is widely sprinkled on the masonry filter bed 1 from the sprinkler pipe 2. When the leachate flows down the stone surface of the masonry filter bed 1, organic matter (BOD component) is adsorbed and decomposed (oxygen decomposition) by the aerobic biofilm generated on the surface of the stone.

  In this way, the water treated by passing through the masonry filter bed 1 is collected by the drainage pipe 5 on the water shielding portion 4 and drained to the treated water tank 3. Then, water is sent to the water sprinkling pipe 2 on the adjacent masonry filter bed 1 by the submersible pump 8 installed in the treated water tank 3, and water is sprinkled onto the masonry filter bed 1 again from the water sprinkling pipe 2. The purified water repeatedly treated through these processes is finally discharged from the treated water tank 3 at the end to the public water area.

  Thus, according to the leachate treatment facility in the present embodiment, a simple biological treatment method such as an activated sludge method, a contact aeration method, a rotating disk method, a carrier method and a membrane separation activated sludge method can be used. It is possible to treat organic matter in the leachate with a configuration. Therefore, the construction cost is low, it is easy to secure engineers for maintenance, and the maintenance cost can be reduced.

  In this leachate treatment facility, the oxygen required for the oxidative decomposition of the leachate by the aerobic biofilm is supplied by natural aeration from the periphery of the masonry filter bed 1, which saves energy, and the oxidative decomposition by the aerobic biofilm Is actively conducted. Further, in the leachate treatment facility according to this embodiment, the drainage port 50 of the drainage pipe 5 is provided above the water surface of the treated water tank 3 as shown in FIG. 2, and the drainage pipe as shown in FIG. 5 has a water passage 51 through which treated water passes and a vent 52 through which air passes, and air is supplied from the inside of the masonry filter bed 1 through the vent 52 of the drainage pipe 5. Therefore, oxidative degradation by aerobic microorganisms is more actively performed.

  Further, when the masonry filter bed 1 is formed by digging into the waste layer R, the diameter of the drainage pipe 5 is increased so that oxygen is efficiently supplied into the masonry filter bed 1. Just do it. Further, if necessary, a ventilation fan can be provided to supply oxygen by forcibly ventilating (forced ventilation). In this case, the ventilation fan is preferably operated using natural energy such as sunlight or wind power.

  Further, in the leachate treatment facility according to the present embodiment, the upper surface of the waste layer R of the existing waste disposal site is disposed on the upper surface of the waste layer R after being shielded by the water shielding part 4, and therefore, the waste of the upper surface of the waste layer R is wasted. Space can be used effectively. In addition, when there is room in the installation space, it is also possible to arrange the masonry filter bed 1 or the like on the lower layer side of the waste layer R. In this case, it is not necessary to pump the leachate up to the waste layer R.

  INDUSTRIAL APPLICABILITY The leachate treatment method and leachate treatment facility of the present invention are useful as a method and facility for treating organic matter in leachate generated from a waste layer at a waste disposal site. In particular, the present invention treats organic matter in leachate with a simple configuration without using advanced biological treatment methods such as activated sludge method, contact aeration method, rotating disk method, carrier method and membrane separation activated sludge method. It is suitable as a leachate treatment method and leachate treatment facility in a waste disposal site.

It is a top view of the leachate treatment facility of the waste disposal site in the embodiment of the present invention. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG.

Explanation of symbols

R Waste layer 1 Masonry filter bed 2 Sprinkling pipe 3 Treated water tank 4 Water shielding part 5 Drainage pipe 6 Leachate control pond 7,8 Submersible pump 50 Drain outlet 51 Water flow part 52 Ventilation part

Claims (7)

A leachate treatment method for treating leachate generated from a waste layer at a waste disposal site,
The leachate stored by a leachate adjustment facility is placed on the filter bed made of a filter medium on which the upper surface of the waste layer is shielded and the aerobic biofilm is generated on the surface from the leachate treatment facility. Pumping up to the filter bed and sprinkling water,
A method for treating leachate in a waste disposal site, comprising: shielding a lower portion of the filter bed, collecting water that has passed through the filter bed, and draining the water out of the filter bed. Leachate treatment method waste disposal site according to claim 1 comprising the further vented to a lower portion of the filter bed. The waste treatment method according to claim 2, wherein the ventilation of the lower part of the filter bed is performed by natural ventilation or forced ventilation. A leachate treatment facility for treating leachate generated from a waste layer at a waste disposal site,
Leachate adjustment equipment for collecting leachate generated from the waste layer;
A filter bed comprising a filter medium on which an aerobic biofilm is generated, and
A watering device comprising a pump for pumping the leachate from the leachate adjustment facility onto the filter bed, and watering the leachate onto the filter bed;
A leachate treatment facility for a waste disposal site, comprising a water shielding portion formed at a lower portion of the filter bed and on an upper surface of the waste layer . The leachate treatment facility for a waste disposal site according to claim 4 , further comprising a water collection and drainage device that collects water that has passed through the filter bed on the water shielding portion and drains the water out of the filter bed. The leachate treatment facility for a waste disposal site according to claim 4 or 5 , further comprising a vent for venting the lower part of the filter bed. The leachate treatment facility for a waste disposal site according to claim 6, wherein the ventilation to the ventilation section is performed by natural ventilation or forced ventilation.

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