Multi-layer landfill bed for filtering landfill leachate

Abstract

The invention relates to a multi-layer landfill bed (10) for filtering landfill leachate accumulating in a landfill, comprising a base seal (12), a drainage layer (22) arranged above the base seal (12), and a liquid-permeable pollutant absorption layer (24) which is designed to filter out and enclose pollutants from the landfill leachate, in particular by adsorption and / or ion exchange.

Description

[0001] Multi-layer landfill base for filtration of leachate

[0002] The invention relates to a multi-layer landfill base for the filtration of leachate accumulating in a landfill, with a base seal and a drainage layer arranged above the base seal.

[0003] Furthermore, the invention relates to a landfill or landfill sections for storing contaminated waste, with at least one multi-layer landfill base and contaminated waste arranged on the landfill base.

[0004] Furthermore, the invention relates to a method for storing polluted waste on a landfill or landfill sections, comprising the steps of: laying a multi-layered landfill base on a landfill site, transferring polluted waste, in particular containing per- and polyfluorinated alkyl substances, onto the multi-layered landfill base and sealing the polluted waste with a surface seal.

[0005] Furthermore, the invention relates to a method for operating a landfill for storing contaminated waste, comprising the step of storing contaminated waste on the landfill.

[0006] Waste to be stored in a landfill can be contaminated with pollutants such as perfluorinated and polyfluorinated alkyl substances. During backfilling, i.e., before a surface seal is installed, precipitation-induced leachate is generated, which can absorb pollutants dissolved from the waste. The contaminated leachate then flows through the drainage layer out of the landfill body and must subsequently be treated.

[0007] When per- and polyfluorinated alkyl substances enter the leachate, the leachate leaving the landfill body must be cleaned using complex technical treatment systems, which means that the storage of contaminated waste leads to a significant increase in the operating costs of a landfill.

[0008] The object underlying the invention is therefore to simplify the storage of contaminated waste in a landfill.

[0009] The object is achieved by the landfill base mentioned at the outset, wherein the landfill base according to the invention has a liquid-permeable pollutant absorption layer which is designed to filter out and enclose pollutants from the seepage water, in particular by adsorption and / or ion exchange.

[0010] The landfill may be contaminated waste. The waste may include contaminated soil or slag. The contaminant absorption layer may comprise one or more layers of material. The drainage layer serves to dewater the landfill. The drainage layer may be a mineral drainage layer. The drainage layer consists, for example, of fill material. The fill material may be, for example, gravel.

[0011] The base seal may comprise a geological barrier layer and / or a bentonite mat and / or a single-layer or multi-layer mineral sealing layer and / or one or more plastic sealing membranes and / or a protective geotextile. The geological barrier layer may, for example, be formed from or comprise a clay material.

[0012] In a preferred embodiment of the landfill base according to the invention, the pollutant absorption layer is arranged above the drainage layer and is designed to filter and contain pollutants from the seepage water before the seepage water reaches the drainage layer. In this case, the pollutant absorption layer can function as a separating layer. The separating layer is arranged between the landfill and the drainage layer and prevents the landfill from mixing with the drainage material of the drainage layer.

[0013] In another embodiment of the landfill base according to the invention, the pollutant absorption layer is arranged below the base seal and is designed to filter and contain pollutants from the seepage water before the seepage water reaches a soil area located beneath the landfill base. If the base seal is leaking or is leaking, or if pollutants, such as per- and polyfluorinated alkyl substances, diffuse through the water-impermeable layers, the pollutant absorption layer can prevent pollutants from being introduced into the soil area beneath the landfill base via contaminated seepage water.

[0014] In a further development of the landfill base according to the invention, the contaminant absorption layer is designed to filter out and contain per- and polyfluorinated alkyl substances from the leachate. The landfill can be waste containing per- and polyfluorinated alkyl substances (PFAS). The waste containing per- and polyfluorinated alkyl substances can include PFAS-contaminated soils or slag. The contaminant absorption layer allows for the rapid absorption and binding of short- and long-chain per- and polyfluorinated alkyl substances. The per- and polyfluorinated alkyl substances are permanently and reliably bound in the contaminant absorption layer, preferably by ion exchange and / or adsorption. By using the landfill base, per- and polyfluorinated alkyl substances are removed from the leachate before it leaves the landfill body via the drainage system.This eliminates the need for a leachate treatment plant constructed outside the landfill body. The contaminant absorption layer preferably has a high capacity for both low and very high PFAS concentrations in the leachate. Furthermore, a landfill base according to the invention is preferred in which the contaminant absorption layer is designed as a geocomposite and / or comprises one or more active substances designed to filter out and entrap per- and polyfluorinated alkyl substances from the leachate. The contaminant absorption layer can have an active substance composition comprising several active substances. The strong bond between the contaminant and the active substance reliably prevents subsequent desorption.

[0015] In another preferred embodiment of the landfill pad according to the invention, one active ingredient of the pollutant absorption layer is an ion exchange resin. The ion exchange resin effectively binds per- and polyfluorinated alkyl substances through ion exchange.

[0016] Furthermore, a landfill base according to the invention is advantageous in which one of the active substances in the pollutant absorption layer is activated carbon. The activated carbon acts as a highly efficient adsorbent. Per- and polyfluorinated alkyl substances are effectively bound by adsorption.

[0017] In a further preferred embodiment of the landfill base according to the invention, the pollutant absorption layer comprises a carrier layer, wherein the carrier layer is preferably formed as a woven fabric, in particular as a geo-fabric, and / or as a scrim, in particular as a geo-scrim, and / or as a nonwoven fabric, in particular as a geo-nonwoven fabric, and / or as a film. The woven fabric and / or the scrim and / or the nonwoven fabric of the carrier layer can be made of polypropylene (PP) or polyester (PET). The carrier layer can have a geogrid reinforcement.

[0018] In another embodiment of the landfill base according to the invention, the pollutant absorption layer has a cover layer, wherein the cover layer is preferably formed as a woven fabric, in particular as a geo-fabric, and / or as a scrim, in particular as a geo-scrimp, and / or as a nonwoven fabric, in particular as a geo-nonwoven fabric, and / or as a film. The cover layer serves as a stabilizer for the one or more active substances and as a protective layer against external influences. The woven fabric and / or the scrim and / or the nonwoven fabric of the cover layer can be made of polypropylene (PP) or polyester (PET).

[0019] The landfill base according to the invention is further advantageously developed in that the pollutant absorption layer has an active substance layer comprising the one or more active substances, which is arranged between the carrier layer and the cover layer. The active substance layer can also comprise heavy metal-binding filter material and / or oil-absorbing filter material.

[0020] The object underlying the invention is further achieved by a landfill of the type mentioned above, wherein the multi-layered landfill base of the landfill according to the invention is designed according to one of the embodiments described above. With regard to the advantages and modifications of the landfill according to the invention, reference is therefore first made to the advantages and modifications of the landfill base according to the invention.

[0021] In a preferred embodiment, the landfill according to the invention comprises several waste-specific storage areas intended for the storage of different wastes, wherein the waste-specific storage areas have different area-specific landfill bases with a base seal and a drainage layer arranged above the base seal. The landfill base of at least one waste-specific storage area for waste containing per- and polyfluorinated alkyl substances preferably comprises a liquid-permeable pollutant absorption layer designed to filter out and contain per- and polyfluorinated alkyl substances from the leachate, in particular by adsorption and / or ion exchange.The landfill base of at least one waste-specific storage area for waste that does not contain per- and polyfluorinated alkyl substances preferably has a liquid-permeable separating layer. The separating layer of the landfill base of the waste-specific storage area for waste that does not contain per- and polyfluorinated alkyl substances is not designed to filter out and contain per- and polyfluorinated alkyl substances from the leachate. The waste-specific storage area for waste containing per- and polyfluorinated alkyl substances is therefore a so-called mono-cell, in which, for example, soils or slag containing per- and polyfluorinated alkyl substances can be stored.

[0022] The object underlying the invention is further achieved by a method for storing pollutant-contaminated waste in a landfill of the type mentioned above, wherein the multi-layer landfill base is designed according to one of the embodiments described above, so that the pollutant-absorbing layer filters out and encloses pollutants, in particular per- and polyfluorinated alkyl substances, from the leachate before the pollutant-contaminated waste is sealed with the surface seal, preferably before the leachate reaches the drainage layer of the landfill base. With regard to the advantages and modifications of the method according to the invention for storing pollutant-contaminated waste in a landfill, reference is first made to the advantages and modifications of the landfill base according to the invention.

[0023] In a preferred embodiment of the method according to the invention for storing pollutant-contaminated waste in a landfill, different types of waste are stored in several waste-specific storage areas, wherein the waste-specific storage areas have different area-specific landfill bases with a base seal and a drainage layer arranged above the base seal. The landfill base of at least one waste-specific storage area for waste containing per- and polyfluorinated alkyl substances preferably comprises a liquid-permeable pollutant absorption layer, which is designed to filter out and contain per- and polyfluorinated alkyl substances from the leachate, in particular by adsorption and / or ion exchange.The landfill base of at least one waste-specific storage area for waste that does not contain per- and polyfluorinated alkyl substances preferably has a liquid-permeable separating layer. The separating layer of the landfill base of the waste-specific storage area for waste that does not contain per- and polyfluorinated alkyl substances is not designed to filter out and contain per- and polyfluorinated alkyl substances from the leachate. The waste-specific storage area for waste containing per- and polyfluorinated alkyl substances is therefore a so-called mono-cell, in which, for example, soils or slag containing per- and polyfluorinated alkyl substances can be stored.

[0024] The object underlying the invention is further achieved by a method for operating a landfill for storing contaminated waste of the type mentioned above, wherein the amount of waste that may be transferred to the multi-layered landfill base before sealing the contaminated waste with the surface seal without exceeding the contaminant absorption capacity of the contaminant absorption layer is determined based on the storage period of the contaminated waste on the landfill base without requiring surface sealing and / or the properties of the contaminated waste and / or the precipitation during the storage period of the contaminated waste on the landfill base without requiring surface sealing, without exceeding the contaminant absorption capacity of the contaminant absorption layer. The storage of the contaminated waste on the landfill preferably takes place according to one of the embodiments described above.

[0025] A preferred embodiment of the invention is explained and described in more detail below with reference to the accompanying drawings.

[0026] Fig. 1 shows a deposit base according to the invention in a schematic representation.

[0027] Fig. 1 shows a multi-layer landfill base 10 for the filtration of leachate accumulating in a landfill.

[0028] The landfill base 10 comprises a base seal 12, a project-specific geogrid 20 arranged above the base seal 12, a drainage layer 22 arranged above the base seal 12 and above the geogrid 20, and a liquid-permeable contaminant absorption layer 24 arranged above the drainage layer 22. The contaminated waste A is located on the liquid-permeable contaminant absorption layer 24. The waste A can, for example, comprise contaminated soils or slag.

[0029] In the state shown, the contaminated waste A is deposited on the landfill base 10, so that the contaminated waste A is not yet sealed with a surface seal against the ingress of rainwater.

[0030] The base seal 12 comprises a geological barrier layer 14 made of clay, a plastic sealing membrane 16, and a protective geotextile 18. The geogrid 22 increases the stability of the landfill base 10.

[0031] The drainage layer 22 serves to drain the landfill. The drainage layer 22 can be a mineral drainage layer and, for example, consist of loose material, such as gravel.

[0032] The liquid-permeable contaminant absorption layer 24 is designed to filter and contain contaminants from the leachate through adsorption and ion exchange before the leachate reaches the drainage layer 22. In addition, the contaminant absorption layer 24 serves as a separating layer between waste A and drainage layer 22.

[0033] The contaminant absorption layer 24 is designed to filter out and contain per- and polyfluorinated alkyl substances from the leachate, so that the landfill can contain waste A containing per- and polyfluorinated alkyl substances. Waste A containing per- and polyfluorinated alkyl substances can include soils or slag contaminated with PFAS. The contaminant absorption layer 24 allows for the rapid absorption and binding of short- and long-chain PFAS through ion exchange and adsorption. By using the landfill base 10, per- and polyfluorinated alkyl substances are removed from the leachate before it leaves the landfill body via the drainage layer 22. This eliminates the need for a leachate treatment plant.

[0034] The contaminant absorption layer 24 is formed as a geocomposite and comprises one or more active substances that filter out and enclose per- and polyfluorinated alkyl substances from the leachate. The contaminant absorption layer 24 can, for example, comprise an active substance composition composed of several active substances. One active substance of the contaminant absorption layer 24 can be an ion exchange resin. One active substance of the contaminant absorption layer 24 can be activated carbon.

[0035] The pollutant absorption layer 24 comprises a carrier layer 26, an active substance layer 28 and a cover layer 30.

[0036] The carrier layer 26 is formed, for example, as a geo-fabric and / or geo-nonwoven fabric. The cover layer 30 is formed, for example, as a geo-fabric and / or geo-nonwoven fabric. The active substance layer 28 contains the one or more active substances and is arranged between the carrier layer 26 and the cover layer 30. The active substance layer 28 can additionally comprise heavy metal-binding filter material and / or oil-absorbing filter material.

[0037] In another embodiment, the contaminant absorption layer 24 can be arranged below the base seal 12 and configured to filter and contain contaminants from the leachate before the leachate reaches a soil area located beneath the landfill base 10. Thus, the ingress of contaminants into the soil area located beneath the landfill base 10 is effectively prevented even if the base seal 12 is leaking or PFAS diffuses through the water-impermeable layers.

[0038] If the landfill base 10 is used in a landfill, the landfill may have several waste-specific storage areas intended for the storage of different wastes, wherein the waste-specific storage areas have different area-specific landfill bases 10 with a base seal 12 and a drainage layer 22 arranged above the base seal 12. The landfill base 10 of a waste-specific storage area for waste A comprising per- and polyfluorinated alkyl substances then comprises a liquid-permeable pollutant absorption layer 24, which is designed to filter out and contain per- and polyfluorinated alkyl substances from the leachate by adsorption and / or ion exchange.The landfill base 10 of another waste-specific storage area for Waste A, which does not contain per- and polyfluorinated alkyl substances, comprises a liquid-permeable separation layer. The separation layer of the landfill base 10 of the waste-specific storage area for Waste A, which does not contain per- and polyfluorinated alkyl substances, is not designed to filter and contain per- and polyfluorinated alkyl substances from the leachate. The waste-specific storage area for Waste A, which contains per- and polyfluorinated alkyl substances, is therefore a so-called mono-cell, in which PFAS-contaminated soils can be stored.

[0039] When operating a landfill for the storage of contaminated waste A, the contaminated waste A is stored in the landfill. Based on the storage period of the contaminated waste A on the landfill base 10 without the need for surface sealing and / or the properties of the contaminated waste A and / or the precipitation during the storage period of the contaminated waste A on the landfill base 10 without the need for surface sealing, it is determined, for example by an electronic data processing device, which amount of waste may be transferred to the multi-layer landfill base 10 before sealing the contaminated waste A with the surface sealing without exceeding the contaminant absorption capacity of the contaminant absorption layer 24. Reference numeral

[0040] 10 Deposit pad

[0041] 12 Base seal 14 Geological barrier layer

[0042] 16 plastic sealing membrane

[0043] 18 Protective geotextile

[0044] 20 geogrids

[0045] 22 Drainage layer 24 Pollutant absorption layer

[0046] 26 carrier layers

[0047] 28 Active ingredient layer

[0048] 30 top layer

[0049] Waste

Claims

Claims 1. A multi-layer landfill base (10) for filtering leachate accumulating in a landfill, comprising a base seal (12) and a drainage layer (22) arranged above the base seal (12); characterized by a liquid-permeable pollutant absorption layer (24) designed to filter and contain pollutants from the leachate, in particular by adsorption and / or ion exchange.

2. Landfill base (10) according to claim 1, characterized in that the pollutant absorption layer (24) is arranged above the drainage layer (22) and is designed to filter out and enclose pollutants from the seepage water before the seepage water reaches the drainage layer (22).

3. Landfill base (10) according to claim 1, characterized in that the pollutant absorption layer (24) is arranged below the base seal (12) and is designed to filter out and enclose pollutants from the seepage water before the seepage water reaches a soil area located below the landfill base (10).

4. Landfill base (10) according to one of the preceding claims, characterized in that the pollutant absorption layer (24) is designed to filter out and enclose per- and polyfluorinated alkyl substances from the leachate.

5. Landfill base (10) according to one of the preceding claims, characterized in that the pollutant absorption layer (24) is designed as a geocomposite material and / or contains one or more active substances which are designed to filter out and contain per- and polyfluorinated alkyl substances from the leachate.

6. Landfill base (10) according to claim 5, characterized in that an active substance of the pollutant absorption layer (24) is an ion exchange resin.

7. Landfill base (10) according to claim 5 or 6, characterized in that an active substance of the pollutant absorption layer (24) is activated carbon.

8. Landfill base (10) according to one of the preceding claims, characterized in that the pollutant absorption layer (24) has a carrier layer (26), wherein the carrier layer (26) is preferably designed as a woven fabric and / or scrim and / or nonwoven fabric and / or film.

9. Landfill base (10) according to one of the preceding claims, characterized in that the pollutant absorption layer (24) has a cover layer (30), wherein the cover layer (30) is preferably designed as a woven fabric and / or scrim and / or nonwoven fabric and / or film.

10. Landfill base (10) according to claim 8 and 9, characterized in that the pollutant absorption layer (24) has an active substance layer (28) comprising the one or more active substances, which is arranged between the carrier layer (26) and the cover layer (30).

11. Landfill for the storage of contaminated waste, with at least one multi-layered landfill base (10), and contaminated waste (A) arranged on the landfill base (10), characterized in that the multi-layer deposit base (10) is designed according to one of the preceding claims.

12. Landfill according to claim 11, characterized by a plurality of waste-specific storage areas which are provided for the storage of different wastes, wherein the waste-specific storage areas have area-specific landfill bases (10) which differ from one another and have a base seal (12) and a drainage layer (22) arranged above the base seal (12).

13. A method for storing polluted waste (A) in a landfill, comprising the steps of: Laying a multi-layer landfill base (10) on a landfill site; Placing contaminated waste (A), in particular containing per- and polyfluorinated alkyl substances, onto the multi-layer landfill base (10); and sealing the contaminated waste (A) with a surface seal; characterized in that the multi-layer landfill base (10) is designed according to one of claims 1 to 10, such that the contaminant absorption layer (24) filters out and encloses contaminants, in particular per- and polyfluorinated alkyl substances, from the seepage water before the contaminated waste (A) is sealed with the surface seal, preferably before the seepage water reaches the drainage layer (22) of the landfill base (10).

14. Method according to claim 13, characterized in that different wastes are stored in several waste-specific storage areas, wherein the waste-specific storage areas have different area-specific deposit bases (10) with a base seal (12) and a drainage layer (22) arranged above the base seal (12).

15. A method for operating a landfill for the storage of contaminated waste (A), comprising the step: Storing polluted waste (A) on the landfill, in particular according to one of claims 13 or 14, characterized in that based on the surface-sealing-free storage period of the polluted waste (A) on the landfill base (10) and / or the properties of the polluted waste (A) and / or the precipitation during the surface-sealing-free storage period of the polluted waste (A) on the landfill base (10), it is determined which quantity of waste may be transferred to the multi-layer landfill base (10) before sealing the polluted waste (A) with the surface seal without exceeding the pollutant absorption capacity of the pollutant absorption layer (24).

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