SK78796A3 - Landfill reclamation - Google Patents

Abstract

A method increasing the capacity of an existing landfill (100) to enable the disposal of additional material therein includes excavating (12) a given volume of material disposed in the existing landfill (100), possibly separating from the excavated material one or more components thereof, comminuting (44) the excavated material sufficiently to permit its close packed disposal in a volume less than the given volume, and placing the comminuted material back into the landfill.

Description

Landfill regeneration

Technical field

The present invention relates to a method and apparatus for increasing the capacity of an existing landfill, thereby allowing additional material to be placed therein.

BACKGROUND OF THE INVENTION

Finding an environmentally friendly landfill site in the US is rare, especially in densely populated urban and coastal areas. Older landfills are closing faster than replacement ones. Landfills are closed for various reasons, in particular as a result of environmental threats, to accept further operation of the landfill in its original state and to make full use of the available space due to resistance of the surrounding public.

The location of new landfills is becoming increasingly difficult as environmental regulations do not allow landfills to be placed on marginal soils (i.e. soils generally unsuitable or undesirable for commercial or residential purposes) where many older landfills are located. Older landfills are closing and new ones have to bid for non-marginal soils that can be used for others, and many people consider it better for purposes. Evidence of this competition can be seen in the fact that there are relatively few open landfill sites in the more densely populated areas of the US.

Incinerators were once considered a solution to landfill problems, but they have met with such public opposition that they may not be the final solution. At the same time, incineration plants and other major known waste treatment technologies normally require landfill space as part of their general approach to waste treatment. For example, recycling and incineration can reduce the amount of waste, but the non-recyclable waste that landfill space is required to accommodate materials and ash. Thus, while the volume to be landfilled may be reduced by these or other known waste treatment methods, the need for landfill space in general cannot be excluded. Those with knowledge of waste management agree that landfill space will become more and more valuable in the next ten or more years.

One method of waste treatment that is relatively successful (i.e., involves most of the new landfill capacity in urban areas of the United States) is to expand the size (area) of some existing landfills. Existing landfills that have been extended are generally well located and continue to operate with public support.

SUMMARY OF THE INVENTION

The invention relates to increasing the capacity of existing landfills not necessarily by increasing the size of the landfills, but instead by regenerating or remodeling the existing landfill space. In accordance with the invention, the material is extracted from an existing landfill, the excavated material being treated to reduce its volume, thereby allowing it to be compacted back to the existing landfill from where it was extracted.

The processing of the excavated material includes various operations such as sorting, crushing (e.g. disintegration) and / or mechanical compaction. Different processing operations can also be performed in different combinations. For example, the excavated material may be sorted to reduce its volume, disintegrate to reduce its volume more, and then sort again to reduce its volume even further. The sorting may be performed on a sorting or separating device, such as a drum separator.

With the invention, it is possible to increase the capacity of an existing landfill in the range of 20 to 80%. it may be obtained between 20 and 80% of the previous volume of the existing landfill. The result may vary depending, for example, on the quality of compaction of the material in the existing landfill and on the type and quantity of the cover layer. With the present invention it is possible to obtain a 50-80%, 65-80% and 70-80% increase in landfill capacity.

Recyclable materials and other valuable constituents of the excavated material can be separated from this prior to being put back in the existing landfill, further reducing the volume of the excavated material. For example, ferrous metals can be separated from the excavated material. Generally, only those components that are present in sufficient quantities will be separated from the excavated material so that they can be effectively recovered and sold.

The extracted material normally contains soil and waste. The soil can be separated from waste and stored for further use (eg as a landfill cover) or sold as backfill material, further reducing the volume of excavated material. In general, more soil is obtained by the process according to the invention than is applied to the cover layer. In addition, the soil can be further cleaned if necessary and then sold as backfill material.

In accordance with the present invention, one or more of the steps of extracting material from an existing landfill, treating it to reduce its volume, and returning the excavated and processed material to an existing landfill may be under temporary closure to cover an existing landfill. Temporary sealing is suitable, for example, to prevent (or at least reduce the amount of) odor spreading to the environment and to reduce noise if necessary.

As part of increasing the capacity of an existing landfill, the invention includes the step of preparing a disposal unit at the site of the landfill that complies with environmental regulations. The excavated and processed material can then be placed in a safe unit. The unit may be located at the site from which the material was extracted, or it may be located elsewhere within an existing landfill. The amount of work required to bring the unit to its current status will vary from site to site. Current environmental regulations require precautions such as sealing layers or caustic treatment equipment.

The invention can be used to increase the capacity of existing landfills that are permitted by the relevant environmental regulations.

Other objects, aspects, features and advantages of the invention will be apparent from the following description and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

In FIG. 1a is a flow chart of the process of increasing the capacity of an existing landfill according to the invention.

In FIG. 1b is a block diagram of an existing landfill.

Fig. 2 is a block diagram of another process for increasing the capacity of an existing landfill according to the invention.

Fig. 3 is a block diagram showing in more detail one step included in the methods of Figs. 1 and 2.

Fig. 4 is a diagram of one method of regenerating a landfill of the invention.

Fig. 5 is a perspective view of the cutting blades of the disintegrator used in the method of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The method of increasing the capacity of an existing, permitted landfill is carried out in stages according to the invention. That is, the landfill is divided into one or more areas and the method described is applied sequentially to each area until the entire landfill area is regenerated by the method of the invention. An alternative to the part-time landfill regeneration is the method of regenerating the entire landfill space in one stage.

Referring to Figures 1a and 1b, the method of the invention for regenerating the space of an existing, permitted landfill 100 and thus increasing the capacity of that landfill 100 typically includes a first step 10 of building a storage space 102 within the landfill 100. The storage space 102 is constructed to meet all regulatory standards (e.g., environmental regulations), so that upon completion it provides a safe storage space for material that has been removed from another part of the landfill 100 and has been processed by the method of the invention. Storage 102 may have environmental control devices, such as e.g. equipment for collecting leachate.

Once the storage space 102 (step 10) has been created, the appropriate volume of material can be extracted (step 12) from the working area 104 within the landfill 100 (ie, from an area other than the storage space 102) and processed (step 14) to reduce it. volume, thereby allowing and processing to store or store material with a smaller volume than the mined volume of the previous volume. Material extraction material from working normally contains waste and soil. A hydraulically operated depth bucket or similar mining equipment may be used on the area 104. The processing step 14 comprises crushing the material (e.g., a disintegrator or other crushing device) to reduce the particle size thereof. 3, 4 and 5, the processing step 14 may additionally consist of a plurality of steps or be carried out in addition to crushing. After processing (step 14) of the excavated material, it is stored (step 16) in place in the storage space 102.

Generally, the drawing (step 12), processing (step 14), and deposit (step 16) steps are repeated as indicated by the back arrow 18 until all material in the working area 104 is extracted, processed and stored. These three steps may be repeated immediately in succession until the working area 104 is emptied or may be repeated only during the working day. Because of its daily interruption, this second method requires more time to empty the work area 104 than the first method. After all the material has been extracted from the working area 104, it is processed and stored in the storage space 102. The working area 104 is reconstructed to comply with current regulations (step 20).

Reconstruction (step 20) may include laying new sealing layers, leach control systems and / or methane recovery systems. In general, measures will be taken as prescribed by the current environmental protection regulations. Technology and construction methods required for busy working professionals in the given

According to one working and

material (step (step 14) as reprocessing area 104) The excavated workspace process area has aligned with the area method of the deposit area to be known by the relevant regulations.

recovery

106 (step repeat, 12) from the new previously and (step 16), which now for the processed material extracted are the device moved

22) and the drawing steps as shown by the arrow 24 of the working area 106 is stored in the previous serving as a storage from the new working area 106. The sequence of steps, including the back arrow 24, is repeated until each landfill area that requires attention.

According to another method of regeneration, after step 20, the processed material from the storage space 102 returns to the working area

104 (step 26), and the device is then moved to the new work area 106 (step 28.), where the extraction, processing and storage is repeated as indicated by the back arrow 30. The material that is extracted (step 12) from the new work area 106 is processed (step 14) as before and then stored in storage 102 (step 16). The sequence of steps, which includes the back arrow 30, is repeated until each area of the landfill that requires attention is processed according to the invention. In this regeneration method, the storage space 102 is used exclusively as a temporary storage site in the landfill.

It does not matter which of the two described methods (or combinations thereof) is used, as a result of this process, the landfill space 100 is regenerated by increasing the landfill capacity 100. As its capacity increases, additional waste may be deposited therein. The method described will make the landfill more environmentally safe by complying with all applicable landfill regulations. Thus, landfills treated in this way can continue to serve their purpose without endangering the environment.

The entire landfill does not close when the treatment according to the invention is started. Some parts of the landfill 100 remain in operation (i.e., receive additional waste) while other parts of the landfill 100 are treated according to the invention. This approach has the advantage that the revenue from the active part of the landfill can be used to fully or partially modify other parts of the landfill. Also, after the first working area has been extracted and adapted to current regulations, this working area can serve as a safe storage unit by receiving waste from external sources, while the other parts of the landfill still have to be treated according to the invention.

According to another method of the invention, the repeating process (arrow 24 and / or arrow 30) described above in FIG. 1a, precedes the sequence of steps that are necessary if the landfill is unable to store the processed material that has been extracted from the initial working area. There are several reasons why the processed material cannot be stored directly in the landfill. One reason is that the landfill capacity is full. The decision whether to create a storage space for processed material extracted from the initial working area directly at the landfill (Fig. 1a) or to transport this processed material for off-site storage (Fig. 2) is made taking into account the current state of the landfill and .

Referring to Fig. 2, after deciding that the processed material extracted from the primary working area of the landfill will be transported outside the landfill, the steps that precede the repetition process (arrow 24 and / or arrow 30) described above in Fig. 1a include the following. The material that is extracted from the initial working area (step 32.) is processed (step 34) as described above and the processed material is transported to landfill (step 36). As shown in return arrow 38, these extraction, processing, and off-land transport steps are repeated until substantially all of the material from the initial working area is extracted. Then, the initial working area is reconstructed to comply with current regulations (step 40). (This reconstruction is performed as described above for step 20 of Fig. 1a). The extraction and processing device is then moved to a new working area (step 42) within the landfill and the process continues in a repeated cycle (arrow 24 and / or arrow 30) as described above. The first working area, which is now environmentally safe, serves as storage within the landfill at least in the first round of the repeated cycle. The foregoing steps 32, 34, 36, 40 and 42 serve to provide safe storage within the landfill when physically and / or economically cannot be done in the first step of the recovery process described.

Referring to Fig. 3, the processing step (step 14 and step 34) used in the methods of Figs. 1a and 2 may include various sub-steps such as crushing (sub-step 44), separation (sub-steps 46 and 48.) and compaction (sub-step 50). These processing steps are shown in a particular order, but it is possible and often advantageous to carry out one or more of these processing steps in a different order than that shown in FIG. It is also possible to repeat and / or exclude some steps. In general, a wide variety of combinations of processing steps are possible.

According to one embodiment of the invention, the treatment is carried out by separating certain components from the excavated material (e.g. by sieving the soil from the excavated material using a sieve and / or a separating device such as a drum separator), crushing (e.g. disintegrating) the excavated material remaining after separation of some components and then separating the components (e.g. by sieving additional soil) from the crushed material. Thus, according to this embodiment, the given volume of the excavated material is reduced by sub-processing steps such as sieving, disintegration, and sieving again. According to another embodiment, the processing steps are shown and processed in the following according to FIG.

Generally, the crushing sub-step 44 is performed to reduce the particle size of the excavated material. The crushing step 44 is preferably performed as a disintegration by means of the low speed shear disintegrator described below according to FIGS. 4 and 5.

The separation steps may be applied to the excavated material. The separation may consist of removing soil from the excavated material (sub-step 46) and / or removing other valuable constituents from the excavated material (sub-step 48).

Soil removal reduces the volume of excavated material. The soil can be separated by, for example, sieving the excavated material and / or by using a drum screen as described below in FIG. Other sieving or separating devices may be used instead of the drum separator. The separated soil can be stored for further use (e.g. as a landfill cover). In general, the regeneration process according to the invention yields more soil than is necessary for the cover layer. Separated soil that is in addition can be further cleaned if necessary and then sold as backfill material.

Removal of other valuable components (sub-step £ 8) will reduce the volume of excavated material. A number of valuable components can be separated from the extracted material, e.g. Ferrous materials (eg metals) can be separated, collected and sold. These metals can be separated e.g. using a magnet. Other separation methods can also be used to remove these metals. Other components that can be separated from the mined shredded material are paper, plastic, wood, aluminum, glass, and the like.

In general, in each of the processing steps 46 and 48, the components removed from the excavated material (e.g., soil or ferrous materials) are valuable components that can be obtained in such an amount that they can be collected and sold profitably. The profits from the sale of these valuable components may be used to pay, in whole or in part, the regeneration of the landfill of the invention.

While the removal of soil and ferrous materials is described in detail, the other components may be removed as long as (i) are valuable and (ii) recoverable in sufficient quantity to be sold profitably.

Compaction (sub-step .50) can be performed to reduce the volume of the excavated material. The compaction can be done by a mechanical compactor as described below in Fig. 4.

As mentioned above, the processing steps have been described in a certain order, but it is possible to perform one or more of them in a different order, as shown in Fig. 3, and it is possible to repeat and / or eliminate later steps. For example, the treatment of the excavated material may include mechanical compaction, ferrous materials and may consist of disintegration, removal of soil, removal of re-compaction. Another example, processing may consist of a first separation, disintegration step and then a second separation step. Generally, each of the processing steps reduces the amount of material that the processing step works with.

According to one embodiment of the landfill regeneration method, the processing (steps 14 and 34 of Figs. 1a, 2 and 3) of the extracted material takes place under temporary closure within the landfill. The drawing step (steps 12 and 32 of Figs. 1a and 1b) and / or the depositing step (step 16 of Fig. 1a) can also be performed under temporary closure. One or more temporary closures may be used to cover the area where these operations are performed. Temporary closures are useful e.g. to prevent the crushed material and / or odor from escaping into the environment), or at least to reduce the amount thereof and to suppress noise during loading, processing and / or storage. Temporary closures may be built before, during, or after the construction of the primary storage 102 of Figure 1b (step 10 of Figure 1a). According to the embodiment of FIG. 2, the temporary closure may be stopped prior to the commencement of extraction (step 32). Temporary closures can be as tent structures e.g. of textile or plastic.

According to FIG. 4, an embodiment of the method of regenerating a landfill consists of constructing a storage space 54 in an existing permitted landfill 52 that meets all possible regulatory standards (e.g. environmental regulations). The storage space 54 is an environmentally safe storage space for the material extracted from the mining boss 56. According to an embodiment, the storage space 54 comprises a sealing layer and a leachate collection system. According to other embodiments, the storage space 54 on the ground comprises a simple plastic layer with an appropriate leach catch system, if necessary.

A hydraulically operated depth shovel 58 is used to extract material from the extraction area 56. The depth shovel 58 deposits the excavated material on a low speed shear disintegrator 60 having a screen at its end through which dirt 62 can fall. As shown by arrow 64, dirt 62 is collected. on heap 66 and used e.g. According to an embodiment of the invention, the disintegrator 60 can crush up to about 100 tons of material per hour and has a 200 horsepower machine to drive the disintegrator 60 cutting / crushing mechanism. Suitable low speed shear disintegrators are commercially available.

Shred Pax Corp. of Wood Shred Pax are a particularly described disintegrant method, up to about 300 tonnes of horsepower. Shred Pax are very effective. materials.

available from and AZ-200 from disintegrators

Depending on the Pax model, it can process <engines with 7 to 300 disintegrators from 68 and 70 companies, which are

According to some embodiments, the extracted material for a separator or, for example, a drum separator, screen,

Dale, IL. AZ-160 models suitable for use as landfill regeneration, a Shred material disintegrator per hour and has, as shown in FIG.

A suitable device is commercially available from The Read Corporation, 25 Wareham Street, Middleboro, Massachusetts 02346, entitled Read Waste Manager Model W / M 3500, or W / M 3000. The separation device 59 is shown as a block for simplicity. According to these embodiments, the excavated material is pre-separated and pre-screened before it reaches the disintegrator 60. The various components may be pre-separated or pre-screened from the excavated material by the apparatus 59. The apparatus 59 may remove the debris 62 from the excavated material and this impurity 62 may be collected in the heap 66 .

Note that, as shown in FIG. 4, the various components in the mining area 56 can be removed from the waste before being excavated by the depth bucket 58, or before being disintegrated by the disintegrator 60 (or prior to the separation device 59, if such a device is used). These components may include rocks and building rum 72 and white goods (eg, household appliances such as tuners, stoves, washing machines, dryers and dishwashers) and tires 74. White goods and tires 74 generally represent recyclable materials. The rocks and building rum 72 represent backfill material that can be placed directly in the storage space 74 without processing.

According to FIG. 4, the des integrator 60 may be followed by a compaction / transport device 76 that mechanically compacts the material and then transports it to the drum separator 78 (or other separation or sorting device). Suitable compacting / conveying equipment is commercially available as the AZ PAX model from Shred Pax Corp. of Wood Dale, IL. This Shred Pax device has a 50 to 75 horsepower engine.

Instead of the disintegrator 60 being followed by a compaction / conveyor device 76, the disintegrator 60 can supply a conveyor system with a metal or rubber band (ie, a conveyor system that does not compact the conveyed material as the compaction / conveyor device 76 does). The compactor / transporter may be preferred over the transporter only, as the compactor / transporter (e.g., device 76) generally eliminates maintenance and belt wear problems, as is the case with metal or rubber conveyor belt systems.

It does not depend on whether a combined compaction / conveying device or only a transport device is used to transfer material from the disintegrator 60 to the drum sorter system 78. The drum sorter 78 (or other separation or sorting device) receives material and removes impurities therefrom. These impurities are collected from it. According to an embodiment, they are collected on the heap 66 for later use as a storage material for the storage space 54. Generally, the drum sorter is a type of screen in which sieving is performed, the incoming material stream being separated into two or more fractions depending on the size. The drum sorter is tilted by a rotating (as shown by arrows 82) sieve-coated drum. The cover screen may be a wire mesh or a perforated sheet, the second type of screen covering being more typical. The tilt and rotation of the drum sorter causes the material to feed through it. Rotation ensures that all the material in the drum separator reaches the sieve cover. Advantages of the drum separator over other sorting systems (eg, sieve screens, disc screens, or electric screens) include the ability of the drum screen to thoroughly mix the flow of material. The material that leaves the drum separator 78 is conveyed to the magnetic separator 80, which removes ferrous materials from it. Ferrous materials are collected. A simple conveyor system is used to convey the material from the drum separator 78 to the magnetic separator 80. The material coming out of the magnetic separator has a reduced volume (i.e., crushed, compacted material substantially free of rocks, building rum, recyclable parts, soil and ferrous materials) is then compacted (e.g., a compactor commercially available from Shred Pax Corp. of Wood). Dale, IL), thereby further reducing its volume. The resulting material is then placed in the storage 54.

The landfill regeneration process of FIG. 4 produces impurities 66 and ferrous materials 82 that can each be sold at a profit, resulting in between 20 and 80% of the volume of the old landfill. According to the embodiment of Fig. 4 and some other embodiments of the invention, the embodiment results in a recovery of from 50 to 80%, and more preferably from 65 to 80%, and most preferably from 70 to 80%.

Other modifications and embodiments will be apparent to those skilled in the art without departing from the spirit and scope of the claims of the invention. Thus, the invention is not defined by the foregoing description but by the following claims.

Claims (2)

PATENT CLAIMS 1. A method of increasing the capacity of an existing landfill to allow the storage of additional material, characterized in that: (A) a material containing one or more components is extracted from an existing landfill; (B) separating one or more of the extracted material; (C) crushed components that were not removed in step (B); and (D) placing the crushed material back into the landfill, wherein the density of the material placed back on the existing landfill increases so that additional material can be used there. Method according to claim 1, characterized in that a storage unit is prepared on site in accordance with environmental regulations.