JP4913334B2 - Waste final disposal site - Google Patents

Description

  The present invention relates to a waste final disposal site that stabilizes, for example, landfilled waste.

In conventional waste final disposal sites, semi-aerobic landfill is generally performed. However, it takes about 15 years for the landfill of the waste, until the waste stabilizes and the final disposal site is abolished. Is said to require 10 to 20 years. In the meantime, it is necessary to keep the leachate treatment facility in operation and maintain the entire facility. For this reason, various early stabilization methods have been devised to stabilize landfill waste as soon as possible after completion of landfill, shorten the maintenance period and reduce costs. The main method is as follows.
(1) A method of removing waste from the waste by washing the waste before reclamation and washing out organic substances and heavy metals.
(2) A method in which air is blown into waste to promote decomposition of organic matter.
(3) A method of promoting stabilization by forcibly circulating water to the waste layer after landfill to elute organic substances and heavy metals.
(4) A method in which a strong oxidizing agent such as hydrogen peroxide is added to the circulating water by the method of (3) above, and the decomposition of the organic matter is forced to proceed to promote stabilization.

The conventional techniques have the following problems, and the current situation is that they are hardly adopted.
(1) Not economically viable: If early stabilization cannot be realized at a lower cost than the maintenance cost corresponding to the shortened maintenance period by applying the early stabilization method, it will be economical. Although not true, in most cases, early stabilization is more expensive. For this reason, the application has been limited to a special case such as a case where it must be stabilized at an early stage for some reason.
(2) High risk: In the case of using a strong oxidizer such as hydrogen peroxide solution, if a water barrier is damaged, or if a harmful substance such as a strong oxidizer or heavy metal leaks to the outside, It leads to great environmental destruction and is very dangerous.
(3) Stabilization is delayed when a large amount of air is blown: In the stabilization method of blowing air into a landfill waste layer, in order to stabilize more quickly, the oxygen supply to aerobic decomposing microorganisms is increased, It needs to be more active. For this reason, when the amount of air to be blown is increased, moisture in the waste layer is removed to dry or the temperature is reduced to lower the temperature, so that there is a high possibility that the activity of decomposing microorganisms is suppressed. Furthermore, the size of the apparatus for sending air increases, the amount of energy consumption increases, and this leads to an increase in costs.
(4) A large amount of sewage is generated by the pre-cleaning method: Since the method of cleaning waste before processing requires a large amount of water for cleaning, a large amount of sewage is generated. In addition, a large water treatment facility is required. Therefore, initial costs and running costs are generated, which does not meet the initial objective of reducing maintenance costs.

  A method for maintaining the function of the waste disposal site for a long time is described in Patent Document 1.

Japanese Patent Laid-Open No. 2003-136032

<1> The present invention is to promote stabilization of waste in a waste final disposal site.
<2> Further, the present invention is to promote the stabilization of waste by reducing the supply amount of air.

The present invention includes an oxygen concentrating device that increases the oxygen concentration of air and supplies it to a waste layer, and a pulsation generating device that imparts pulsation to the air whose oxygen concentration has been increased through the oxygen concentration compressing device. In the waste final disposal site, the pulsating air is supplied to the waste layer.
Also, the present invention further includes an ultrasonic oscillator, and supplying the air for example evenly while applying ultrasonic waves to the waste layer, in final waste disposal sites.

  As described above, the waste final disposal site according to the present invention supplies the high oxygen concentration air to the waste layer by the oxygen concentrating device, or pulsates the air by the pulsation generating device, for example, evenly the waste layer. Since the air can be supplied to the waste layer by, for example, being evenly vibrated by the ultrasonic oscillator, the stabilization of the waste can be promoted with a small amount of air supplied.

<1> Waste final disposal site equipped with an oxygen concentrator The waste final disposal site has a storage place where waste can be stored, for example, a waste layer such as landfill waste. FIG. 1 shows a waste final disposal site using a gas separation membrane device as an oxygen concentrator for increasing the oxygen concentration in the air. By using the oxygen concentrator, the waste layer can be stabilized at an early stage.

  The gas separation membrane device is an oxygen concentrator using a membrane, and the exhaust side is sucked with a blower or the like to make a negative pressure. The oxygen concentration on the exhaust side can be increased by the pressure difference from the suction side generated by this. With this gas separation membrane device, air having an oxygen concentration or oxygen altitude of about 21% can be raised to a concentration higher than this concentration, for example, about 30%, and this high concentration oxygen air can be separated into gas. A blower connected to the membrane device and an intubation tube connected to the blower and inserted into the waste layer are blown into the waste layer and supplied.

  Blowing high-concentration oxygen air increases the oxygen concentration inside the waste layer and activates the activity of aerobic degrading microorganisms. Thereby, decomposition | disassembly of the organic component contained in the waste which is one of the factors which delays stabilization of a landfill waste can be completed at an early stage. According to this method, when the same amount of oxygen is supplied into the waste layer, the amount of air blown is about 40% less than when the oxygen concentrator is not used.

  Since the amount of air blown can be reduced, temperature change and humidity change in the waste layer due to air blown are reduced, and it becomes easy to maintain a good environment against aerobic decomposing microorganisms. Furthermore, in order to blow a large amount of air, it is necessary to increase the scale of the equipment, such as increasing the diameter of the intubation tube or increasing the number of tubes, and there is a problem that the equipment cost increases. Then it is not necessary. In addition, because no chemicals such as strong oxidizers are used, the environment around the final disposal site can be protected, and water is not used, so the load on the water treatment facility is not increased and the waste is stabilized more quickly. Can be If a gas separation membrane device is used as the oxygen concentrating device, there is no consumable material such as chemicals in particular, and therefore no residue is generated, so that it can be more environmentally friendly.

  In addition, although the method of supplying oxygen directly using an oxygen cylinder etc. can be considered, in this method, since it is necessary to permanently install a large amount of high-purity high-pressure oxygen such as an oxygen cylinder, there is a high risk. (2) Since the stabilization period is likely to range from months to years, separate management is required, such as periodically replacing oxygen cylinders during this period, resulting in a considerable increase in costs along with oxygen purchase costs. (3) A device for adjusting the oxygen concentration is required separately. Because of the above problems, the method of using an oxygen cylinder is not realistic.

<2> the final waste disposal sites Figure 2 in combination with the upper cover sheet, Rutotomoni using a gas separation membrane system as an oxygen concentrator, shows a final waste disposal site in combination with top cover sheet. The description of parts that are not changed is omitted.
Here, the upper part of the waste layer, for example, the landfill surface, is covered with an upper cover sheet so that a large amount of high-concentration oxygen air blown into the waste layer through the blower and the intubation pipe does not escape to the outside.
During the operation of blowing air, for example, a part of the skirt of the upper cover sheet is raised (may be configured to be raised by the air pressure in the upper cover sheet), or provided in advance in the upper cover sheet The upper cover sheet can be evacuated by opening an air vent valve or the like.
By configuring in this way, the efficiency of supplying oxygen to the waste layer is increased, so that the cost can be reduced by intermittent operation of air blowing.

  Further, for example, the oxygen concentration in the upper cover sheet or the waste layer is measured, and when the oxygen concentration is equal to or higher than a predetermined value, the air blowing is stopped, and when the oxygen concentration falls below the predetermined value, the air blowing is resumed. It may be configured. If comprised in this way, it will become possible to aim at the further efficiency improvement of the air blowing operation.

<3> the final waste disposal sites Figure 3 a blower in combination for suction, shows a gas separation membrane using the apparatus Rutotomoni waste final disposal site in combination with blower for sucking the oxygen concentrator Yes. The description of parts that are not changed is omitted.
Here, the upper part of the waste layer is covered with an upper cover sheet, and high-concentration oxygen air is supplied directly from the gas separation membrane device into the upper cover sheet.
On the other hand, an intake pipe is inserted into the waste layer, and a blower is connected to the intake pipe. Then, the air in the waste layer is sucked by this blower, whereby the high-concentration oxygen air supplied from the gas separation membrane device is widely circulated and permeated into the waste layer.
Even with such a configuration, the efficiency of supplying oxygen to the waste layer can be increased.

  In such a case, for example, the oxygen concentration of the air to be sucked is measured, and as in the first modification, air supply and suction are stopped when the oxygen concentration is equal to or higher than a predetermined value, and the predetermined value is set. It can be configured to resume air supply and suction when it falls below. Alternatively, the oxygen consumption of the waste layer can be predicted, and the air supply and suction can be intermittently operated based on the predicted oxygen consumption.

<4> Waste final disposal site for adding pulsation to supply air FIG. 4 shows a waste final disposal site for stabilizing the waste layer at an early stage by adding pulsation to the supply air. A blower is connected to the air intake port, and a pulsation generating device is additionally connected after the blower. The pulsation generating device pulsates the air and blows it into the waste layer through the intubation tube. With such a configuration, it is possible to improve the penetration of air into the waste layer. In addition, since the vibration is generated in the waste layer, the generation of air passages in the waste layer can be suppressed, and air can be supplied evenly into the waste layer. And the washing-out effect by air blowing of a volatile substance etc. and the decomposition | disassembly rate of organic substance can be improved, and the influence range can be expanded.

  The pulsation generator can be generated by electromagnetically opening and closing a valve, or rotating a wing using an air flow, etc. like a siren, and blocking the air flow with the wing like a fence. There is a method of generating pulsation. The period of pulsation is, for example, about 0.01 Hz to 40,000 Hz.

<5> Waste final disposal site where ultrasonic waves are applied to the waste layer and air is blown Figure 5 shows the waste that is stabilized early by applying ultrasonic waves to the waste layer while blowing air Indicates the final disposal site. Air is blown with a blower and an intubation tube. On the other hand, an ultrasonic oscillator is inserted into the landfill, and ultrasonic waves are applied to the waste layer. As a result, it is possible to improve the penetration of air into the waste layer and to generate vibration in the waste layer. Air can be supplied evenly. In order to facilitate the propagation of ultrasonic waves to the waste layer, it is better to submerge the waste layer by internal storage, and in order to facilitate the passage of air through the waste layer, it is better not to submerge, It is advisable to set conditions as appropriate in consideration of the properties and stabilization status of the waste, such as repeated submersion and non-submersion. With such a configuration, it is possible to increase the washing-out effect of water and air such as a volatile substance and the like, and the decomposition rate of the organic matter, and the range of influence of air ventilation can be expanded.

  When the oxygen concentrator, the pulsation generator, and the ultrasonic oscillator are used in combination, the effects of each device can be obtained and the stabilization of waste can be further promoted.

Diagram showing waste final disposal site using oxygen concentrator A figure showing the final disposal site for waste together with the upper cover sheet Shows the final waste disposal site using in combination a blower for sucking Diagram showing the final disposal site for waste using a pulsation generator Diagram showing the final disposal site for waste using an ultrasonic oscillator

Claims (2)

An oxygen concentrator that increases the oxygen concentration in the air and supplies it to the waste layer ;
Comprising a pulsation generator for imparting pulsation to air having an increased oxygen concentration through the oxygen concentration compressor ;
Characterized by supplying pulsation to the air and supplying the pulsating air to the waste layer,
Waste final disposal site. The waste final disposal site according to claim 1 , wherein an ultrasonic oscillation device is provided in the waste layer in the waste disposal site, and air is supplied while irradiating the waste layer with ultrasonic waves.

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