Infiltration unit for storing leachate on landfills and a landfill with an infiltration unit

Abstract

Infiltration unit (1) for storing leachate on landfills, comprising a plurality of infiltration baskets (2) which are enclosed by a fleece (3) in such a way as to form a transportable infiltration unit (1) which is transported prefabricated to a construction site and is connected on site to an inlet for the leachate by means of a connection adapter (5) arranged thereon, wherein the infiltration baskets (2) enclosed by the fleece (3) are enclosed in a watertight manner by a sealing layer (4), wherein the sealing layer (4) and the infiltration baskets (2) are made of an acid- and alkali-stable plastic.

Description

The invention relates to a drainage unit for storing seepage water on landfills and to a landfill installation having a drainage unit.Dewatering of landfills involves handling precipitation and groundwater which drains off landfills. In this case, landfill seepage water arises as a result of the infiltration of rainwater, contaminated surface water, but also as a result of intrinsic moisture of the deposited substances. In the event of damage to landfill plants, seeping water may also be produced by the penetration of ground water and foreign water.The seeping water dissolves chemical compounds from the landfill material, so that the water comprises ingredients which can have particularly harmful properties due to the landfill material. If percolating water passes untreated into adjacent bodies of water in the landfill, it is a risk for the environment.It is known during operation of a landfill to separate seeping water from uncontaminated surface water in order to keep the size of the seeping water container as small as possible. In particular in the case of high precipitation quantities, as a result of heavy rain events, it is known to provide reserve basins which are filled only rarely and briefly, in order to avoid uncontrolled escape of percolating water.Usually, in landfills, the percolating water is conducted to a percolating water treatment. In the percolating water treatment, it is put into a treated state before it leaves the landfill. The duration of the preparation depends on many factors.Seeping water treatment containers and reserve basins of this type are open installations which consist of a cover on the bottom side, which runs over a slope in order to form the edge of a fillable volume. For this purpose, an open basin with film can be simply sealed and the seeping water stored therein.Such basins are disadvantageous insofar as the surface is lost or cannot be used otherwise. Open basins have the disadvantage that rainwater can easily rain clean, so that the amount of water to be treated increases. It has also been shown that algae form as a result of solar radiation.It is the object of the invention to provide a drainage unit for storing percolating water in landfills and a landfill with a drainage unit, which overcome the disadvantages in the prior art and in particular improve the area utilization of the landfill installation.The invention relates to a drainage trench unit for storing drain water on landfills, comprising a plurality of drainage trench baskets which are surrounded by a fleece in such a way as to form a transportable drainage trench unit which is transported prefabricated to a construction site and is connected on site at the construction site (only) to an inlet for the drain water by means of a connection adapter arranged thereon. The drainage baskets enclosed by the fleece are enclosed in a watertight manner by a sealing layer. The sealing layer and the drainage baskets are made of an acid- and alkali-stable plastic, such as polyethylene, polypropylene or polytetrafluoroethylene. By installing the drainage unit according to the invention into the soil for storing percolating water on landfills, many advantages can be realized and the area utilization of such landfill installations can also be improved.Advantageously, the sealing layer comprises a first sealing layer and a separate second sealing layer. The first sealing layer advantageously completely encloses the second sealing layer, so that there are two separate boundary surfaces for the percolating water enclosed in the drainage unit.Advantageously, the first sealing layer and the second sealing layer form an air-tightly sealed intermediate space. The air-tightly sealed space can be formed by completely closing each sheet by itself. This enables the arrangement of a pressure sensor in the interspace for leakage detection.Advantageously, a non-woven material that is absorbent over the entire surface is arranged between the first sealing layer and the second sealing layer. The nonwoven material can be a multilayer, filter- and pressure-stable system nonwoven with random laid scrim as core and with mechanically consolidated nonwoven fabrics applied over the entire surface on both sides.Preferably, the first sealing layer is made of an elastic sheet material and a second sealing layer is made of an elastic sheet material. An example of an elastic film material is a plastic sealing web having a thickness in the range from 2 mm to 8 mm.Alternatively, the first sealing layer may be made of a rigid sheet material and the second sealing layer may be made of an elastic sheet material. The rigid sheet material is preferably made of thermoplastic materials such as PP (polypropylene), HDPE (high density polyethylene), PVDF (polyvinylidene fluoride) and PVC (polyvinylidene chloride), particularly preferably in a double-walled configuration.An alternative embodiment of the sealing layer provides that the first sealing layer is made of an elastic foil material and a second sealing layer is made of a rigid plate material.A further alternative embodiment of the sealing layer provides that the first sealing layer is made of an elastic foil material and the second sealing layer is a rigid plate material.Advantageously, the drain trench unit has a length in the range of 2 m to 18 m, a width in the range of 0.5 m to 2.5 m and a height in the range of 0.5 m to 3 m.Preferably, the drainage trench unit has at least two drainage trench baskets arranged on one another and at least one clamping element enclosing the drainage trench baskets arranged on one another.Preferably, the clamping element is a strip comprising the drainage baskets on the outside, wherein the end sides of the strip are connected to each other in such a way that the strip can be changed in its length in order to clamp the drainage baskets located therein. The clamping element is preferably made of a metal or plastic, wherein the clamping element comprises a turnbuckle.The drainage trench unit preferably comprises at least one edge protection element, wherein the at least one edge protection element is designed in such a way that it is arranged on outer edges of the drainage trench baskets in the contact region with the clamping element.A further aspect of the invention relates to a landfill installation having at least one drainage unit, as described here.Preferably, at least two drainage units are connected separately in the landfill installation in such a way that rainwater is supplied in one drainage unit and percolating water is supplied separately therefrom in the further drainage unit.The invention is additionally explained below with reference to the examples shown in the drawings.The following are shown: FIG. 1 shows a drainage unit according to the invention for storing percolating water on landfills; FIG. 2 shows the drainage trench unit from FIG. 1 in a partially cut-away illustration; FIGS. 3 ato d show a detail of the drain unit from FIGS. 1 and 2 with different wall structures; and FIG. 4 shows a drainage trench installation having two drainage trench units.FIG. 1 shows an example of a drainage trench unit 1 for storing percolating water in landfills. Under the closed envelope, a plurality of drainage baskets are enclosed by a fleece in such a way as to form a transportable drainage unit, which is transported prefabricated to a construction site and is connected on site at the construction site to an inlet for the percolating water by means of a connection adapter arranged thereon.The drainage baskets enclosed by the fleece are enclosed in a watertight manner by a sealing layer 4. The sealing layer 4 and the drain baskets are made of an acid- and alkali-stable plastic. The sealing layer 4 comprises a first sealing layer and a second sealing layer which completely enclose each other, see FIG. 3.The drainage trench unit shown has a length in the range from 2 m to 18 m, a width in the range from 0.5 m to 2.5 m and a height in the range from 0.5 m to 3 m.FIG. 2 is the drainage trench unit for storing percolating water on landfills from FIG. 1 in a partially cut-away illustration. The drainage trench unit 1 shown in this example has eight drainage trench baskets 2 arranged on top of each other, which are surrounded by a clamping element 12. The clamping element 12 is a strip of plastic or metal surrounding the drainage baskets 2 on the outside. The end sides of the strip 12 are connected to one another via a clamping element in such a way that the strip 12 can be varied in its length in order to clamp the drain baskets 2 lying therein. The drainage trench unit 1 has four edge protection elements 13.In the example shown (see enlarged detail), the first sealing layer 41 and the second sealing layer 42 form an air-tightly sealed intermediate space, so that leak detection is possible by means of a pressure sensor (not shown).It is also possible for an absorbent nonwoven material 6 to be arranged over the entire surface between the first sealing layer 41 and the second sealing layer 42, so that leak detection by means of a moisture sensor is possible.FIGS. 3 ato deach show a section of the wall of the drain trench unit from FIGS. 1 and 2 with different variants in the wall structure.The sealing layer 4 and the drain baskets 2 are made of an acid- and alkali-stable plastic. The sealing layer 4 comprises (or consists of) a first sealing layer 41 and a second sealing layer 42 which completely enclose one another.As shown in Fig. 3a, the first sealing layer 41 is made of an elastic sheet material (solid line) and the second sealing layer 42 is made of an elastic sheet material (solid line).As shown in Fig. 3b, the first sealing layer 41 is made of an elastic sheet material (solid line) and the second sealing layer 42 is made of a rigid plate material (dotted line).As shown in Fig. 3c, the first sealing layer 41 is made of a rigid plate material (broken line) and the second sealing layer 42 is made of an elastic sheet material (solid line).According to FIG. 3 d, the first sealing layer 41 is made of a rigid plate material (dashed line) and a second sealing layer 42 is made of a rigid plate material (dashed line).In FIG. 4, a landfill facility 10 with two drainage units 1 is described in relation to the above figures. The at least two drainage trench units 1 are connected separately in such a way that rainwater is supplied in one drainage trench unit and, separately therefrom, seepage water 111 is supplied in the further drainage trench unit for the seepage water treatment 112.

Claims

A drainage trench unit (1) for storing drain water at landfills, comprising a plurality of drainage trench baskets (2) surrounded by a fleece (3) in such a way as to form a transportable drainage trench unit (1) which is pre-cast transported to a construction site and is connected on site at the construction site to an inlet for the drain water by means of a connection adapter (5) arranged thereon, wherein the drainage trench baskets (2) surrounded by the fleece (3) are surrounded in a watertight manner by a sealing layer (4), wherein the sealing layer (4) and the drainage trench baskets (2) are made of an acid- and alkali-resistant plastic.The drainage trench unit (1) according to claim 1, wherein the sealing layer (4) comprises a first sealing layer (41) and a second sealing layer (42).The drain trench unit (1) according to claim 2, wherein the first sealing layer (41) and the second sealing layer (42) form an air-tightly sealed space.The drain trench unit (1) according to claim 2 or 3, wherein an absorbent nonwoven material (6) is arranged over the full surface between the first sealing layer (41) and the second sealing layer (42).The drain trench unit (1) according to any one of claims 2 to 4, wherein the first sealing layer (41) is made of an elastic sheet material and the second sealing layer (42) is made of an elastic sheet material.The drain trench unit (1) according to any one of claims 2 to 4, wherein the first sealing layer (41) is made of a rigid plate material and the second sealing layer (42) is made of an elastic sheet material.The drain trench unit (1) according to any one of claims 2 to 4, wherein the first sealing layer (41) is made of an elastic sheet material and the second sealing layer (42) is a rigid plate material.The drain trench unit (1) according to any one of claims 2 to 4, wherein the first sealing layer (41) is made of a rigid plate material and a second sealing layer (42) is a rigid plate material.The drainage trench unit (1) according to any one of the preceding claims, wherein a length in the range of 2 m to 18 m, a width in the range of 0.5 m to 2.5 m and a height in the range of 0.5 m to 3 m.The drainage trench unit (1) according to one of the preceding claims, wherein the drainage trench unit (1) comprises at least two drainage trench baskets (2) arranged on one another and at least one clamping element (12) enclosing the drainage trench baskets (2) arranged on one another.The drain unit (1) according to claim 10, wherein the tension member (12) is a strip comprising the drain baskets (2) on the outside, and wherein the end sides of the strips are connected to each other such that the strip is changeable in length to tension the drain baskets (2) therein.The drainage trench unit (1) according to claim 11, wherein the clamping element (12) is made of a metal or plastic and wherein the clamping element (12) comprises a turnbuckle.The drainage trench unit (1) according to any one of claims 10 to 12, wherein the drainage trench unit (1) comprises at least one edge protection element (13), and wherein the at least one edge protection element (13) is configured such that it is arranged on outer edges of the drainage trench baskets (2) in the contact region with the clamping element (12).Landfill installation (10) having at least one drainage unit (1) according to one of the preceding claims.Landfill installation (10) according to Claim 14, wherein at least two drainage units (11, 12) are connected separately in such a way that rainwater is supplied in one drainage unit (11) and percolating water is supplied separately therefrom in the further drainage unit (12).

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