FI12722Y1 - System for treating storm water - Google Patents

Abstract

A system (1) for pre-treatment of stormwater, the system (1) comprising: a first vessel (2), at least one drain pipe (3) configured to be arranged in the first vessel (2) in a first material layer (4), and at least one liquid flood mechanism (5) coupled to said at least one drain pipe (3) and configured to be arranged in the first vessel (2) in such a way that it extends from the first material layer (4) through a second material layer (15) and a third material layer (6) to a space (14) between the third material layer (6) and an edge (7) of the first vessel (2), in which space at least one inlet opening (10) of said at least one liquid flood mechanism ( 5) is arranged, characterized by at least one first outlet opening (8) configured to be connected to at least one outlet pipe (9) in such a way that a liquid flowing through at least one of said at least one drain pipe (3) and said at least one liquid over the floating mechanism (5) is led to the outside of the first vessel (2). In addition, protection requirements 2-12.

Description

FLUID TREATMENT SYSTEM

TECHNICAL FIELD The present invention relates to a system for treating stormwater. Certain embodiments of the present invention relate to a stormwater filtration system.

BACKGROUND Pollution in stormwater is increasingly considered to be a source of significant environmental problems. In urban environments, there are limited opportunities for water to flow out - of course. Waste, sediment, chemicals, and other contaminants accumulate in the runoff as it flows over soil and impermeable surfaces. Rainwater runoff transfers varying amounts of pollutants such as oil / fat, phosphorus, nitrogen, bacteria, heavy metals, pesticides, sediment, nutrients and other inorganic and organic matter, potentially damaging surface waters, penetrating groundwater and affecting aquifers. Examples of pollution sources include leakage from a chemical plant, soapy water from a car wash, excessive fertilizer runoff from a lawn in a residential area, vehicle emissions (e.g. oil, grease, antifreeze) or wear of vehicle materials (e.g. brake pads, metal abrasion to metal, corrosion). Pollutants are commonly found in the profile of stormwater in both soluble and insoluble forms, such as nitrogen, phosphorus, zinc, copper, petroleum hydrocarbons, and pesticides in varying concentrations. These materials N remain varying in degree of solubility and displacement, with some being more mobile than others. Some materials have a chemical affinity to adsorb / absorb and = accumulate in sand particles, sediment or other non-aqueous substances which, according to rainwater, have migrated during migration, thus increasing the mass E of the concentration. = Stormwater = treatment systems - typically - reduce - the need for x coating, curb and stormwater gutter attachments, piping, S inlet structures, and stormwater basins by treating runoff at its source instead of the N end of the piping system.

There are various methods and systems for treating stormwater, for example stormwater tanks with a sand separator / sludge separator, containment / damping tanks, basins or screens, pressures, wetlands, impregnation systems, chamber filters, membrane filters, and rain gardens or biosafers. Bio-containment practices such as rain gardens and sand filters began to be used in the 1990s. Bio-retention is typically defined as the filtration of stormwater runoff by a plant / soil / microbial complex to collect, remove, and bypass contaminants = by a variety of physical, chemical, and biological processes. Bio-retention is a practice that uses gravity to absorb stormwater runoff into natural or engineered media complexes, while allowing some degree of sediment collection / separation and promoting the biodegradation of transported contaminants. Rainforests rely on plant systems to further strengthen microbial activity and assimilate and take in pollutants such as phosphorus, nitrogen and zinc in their soluble forms. In addition to stormwater runoff - treatment, bio-retention systems further slow down the flow of stormwater by retaining water in the filter material. In addition, the amount of stormwater can be reduced by soaking in or after the bio-retention unit, and to some extent by evaporation from the plants. An example of a bio-retention system is the so-called bio-printing. The ground is made - a pit, for example, by digging the soil. The at least one sewer pipe can then, for example, be placed inside the collecting layer of the pit earth. Alternatively, a geomembrane is provided between the ground and the collection layer to provide a liquid impermeable structure. Alternatively, a geotextile is arranged between the ground and the collection layer to separate the biopentry structure from the ordinary soil. Typically, the geotextile N 25 - is then placed between the collection layer and the Jfiltration layer =. > The filtration layer can also be used for growing plants, or an additional growing layer 2 is arranged on top of the filtration layer. Typically, a dam space is also provided so that the water flowing into the system I through the flow inlet is not immediately diverted: from the system through the outlet.

S 3 30 - US 8,333,885 BI describes a stormwater treatment system and method O for removing sediment, chemical contaminants and waste from stormwater runoff> utilizing bio-containment practices involving physical, chemical and biological processes by running stormwater runoff through a multi-stage filtration and treatment chain. The effluent is initially directed to a pretreatment collection tank located mainly inside or outside the open-bottomed, multidimensional tank, whereby the migrated sediment and other transportable material is collected and collected before the transfer, filtration and treatment continue through the medium filtration bed. The tank contains a living plant whose roots are in the medium filtration layer and are able to expand beyond the boundaries of the tank through an opening in one or more side walls. The treated water can further be directed to a separate compartment or storage area for further filtration and temporary collection and storage, or discharged outside the tank. A vertically placed overflow / bypass piping device can be included in the stormwater treatment system to provide additional water transport. In addition, auxiliary filtration and storage equipment can be connected to the stormwater treatment system in the event of a change in conditions. WO 2017/205087 A1 discloses a saturated stormwater filtration system with downstream layered multi-medium filters. The filtration system may include an upstream pretreatment tank and then a filtration tank. It also includes a snorkel tube as an adjustable main control or internal baffles. The system includes gravity-operated partially saturated stormwater media filters to harness the potential energy of stormwater from the downcomer and streams pumped from the stormwater catchment to allow contaminated stormwater to be hydraulically controlled through gravity through a series of filter media layers. In view of the above, it would be advantageous to provide a system for the treatment of stormwater.

S & © = 25 SUMMARY OF THE INVENTION

N E The invention is defined by the features of the independent claim. Some specific embodiments are defined in the dependent claims.

S S In accordance with one aspect of the present invention, there is provided a system N comprising a first vessel, the at least one drain pipe configured - to be arranged within the first vessel in a first layer of material,

at least one liquid overflow mechanism connected to said at least one drain pipe and configured to be arranged within the first vessel so as to extend from the first layer of material through the second layer of material and the third layer of material to a space between the third layer of material and the first container rim, and at least one first outlet configured to connect at least one that the liquid flowing through at least one of said at least one drain pipe and said at least one liquid overflow mechanism is directed outside the first vessel.

Some embodiments of the aspect may comprise at least one feature from the following list:

e at least one first inlet or inlet of said at least one liquid overflow mechanism is arranged in the space between the third layer of material and the edge of the first container at least one second container is connected to at least one side of said first container edge or edge said at least one second outlet through the second outlet or outlet wall of the second vessel is positioned so that liquid is able to flow through said at least one second outlet into the space between the third material layer and the rim of the first vessel said at least one second vessel is configured to collect material contained within the second vessel

N e second = material layer is = configured to filter

> 25 fluid flowing from the material layer to the first material layer

= e first material layer first material first

- the grain size is larger than the second of the second material of the second material layer

& grain size

The at least one outlet pipe mentioned in 3e is a pipe with a continuous outer surface, or

N 30 tube with a number of openings through the outer surface

S e the first diameter of said at least one drain pipe and the second diameter of said at least one outlet pipe are identical between the at least two adjacent layers a fabric e the grain size of the material of the first material layer is between 0-32 mm, in particular between 16-32 mm e the grain size of the second material layer is between 0-20 mm, in particular between 0-16 mm e the grain size e of the material of the first material layer is larger than the grain size e of the material of the second material layer e said at least one overflow mechanism comprises a perforated cover, grid, leaf grille, dome grille, cover with at least one opening flow through the structure, and correspondingly said at least one liquid overflow mechanism comprises an overflow pipe e said at least one liquid overflow mechanism comprises a T-shaped pipe connector e said at least one overflow mechanism comprises a T-shaped pipe connector said at least one overflow mechanism is partially arranged inside the first container e said at least one overflow mechanism is completely arranged inside the first container e said first container comprises a base and four side walls e said at least one second container comprises a base and four side walls e said at least one the second container comprises a cover in the form of a grid e the first container is made of plastic material, steel, concrete, aluminum, fiberglass or any other suitable durable N 25 material 3 e said at least one second container is made of plastic material,> steel, aluminum, fiberglass or any other of a suitable durable material N e, the diameter of said at least one outlet pipe is between 100-200 mm, S 30 for example 160 mm N e the diameter of said at least one drain pipe is between 100-200 mm, S for example i 160 m said diameter of said at least one overflow pipe is between 100-200 mm, for example 160 mm e said at least one first outlet is arranged below the second layer of material e the system is configured = to allow - at least - one additional filtration layer inside the first vessel The rainwater treatment system can be made by equipping a first vessel, providing at least one drain pipe within the first vessel, providing at least one liquid overflow mechanism within the first vessel, and connecting - said at least one liquid overflow mechanism to said at least one drain pipe.

The manufacturing process may further comprise at least one of: e connecting said at least one liquid overflow mechanism to at least one first outlet configured to be connected to the at least one outlet tube e connecting said at least one first outlet tube to said at least one liquid overflow mechanism e providing at least one of a first layer of material, a second layer of material and a third from the material layer inside the first vessel e a T-shaped pipe connector of said at least one liquid overflow mechanism is connected to at least one of said overflow pipe, said at least one 2 sewer pipe and outlet pipe N e is connected as a perforated lid, grid, leaf grille, dome grille, cover with at least S to allow the liquid to flow through the structure, N and the like, at least one second vessel is connected to the overflow pipe E e on at least one side of the first vessel e on the sides s e of the rim, a second container is placed so that the liquid is able to flow through said at least one second outlet in the space between the third layer of material and the rim of the first container

Significant advantages are achieved with certain embodiments of the present invention.

A system for treating stormwater is presented here.

The system can be used, for example, in residential, urban, industrial or commercial areas.

The system is capable of purifying stormwater from contaminants such as heavy metals, oils and nutrients.

Purification takes place by various mechanisms in the filtration bed as well as in the vegetation.

Pollution concentrations can thus be controlled.

According to some embodiments, stormwater is not absorbed into the surrounding soil, allowing installation in areas with challenging soil conditions.

The installation of a prefabricated system can be done relatively quickly compared to on-site bio-retention systems.

The system only needs to be placed at the bottom of the trench and filled with layers of material.

In addition, according to some embodiments, the outlet pipe is connected to an external piping system.

The system is easy and safe to handle due to its light weight and lifting properties.

Anchoring the system is only required in areas with high groundwater, or in case the system is left unfilled with layers of material for later finishing.

According to certain embodiments, the system for treating stormwater according to at least some embodiments of the present invention has a compact size, for example 12 m x 1.3 m x 2.4 m, with a coverage area of 3.12 m ”. Such a standardized solution is easy to dimension and install.

The effective catchment area per system is about 130-150 m ”. The installation of the system requires minimal space due to the compact dimensions of the system, and thus the land can be used for more valuable purposes, such as parking lots and wider streets.

The coating can extend all the way to the edge or edge of the system for good N 25 integration and easy maintenance.

In addition, the appearance of the system is pleasant 3 due to the plants growing in the first container.

N The retention and cleaning capacity of the system depends on the type of filter material E selected.

Slow filtration means better cleaning properties, but the ability 2 to handle intense and frequent rains is often weaker. The system of the present invention can be filled with different filtration materials 5 depending on the site conditions.

The system of the present invention is easy to maintain. Waste and scrap can be removed from the surface of the growth layer as needed. Plants should be cared for and cared for as needed. Changing the filter material is easy thanks to the first container-shaped container. The filter material, or at least the upper part of it, must be replaced when the flow capacity decreases significantly. The entire filter material only needs to be replaced when the cleaning efficiency is significantly reduced. The change of filter material can be done manually or with a small excavator. According to certain embodiments of the present invention, the system comprises a sand separator to remove sand from the runoff before the runoff is directed to the growth layer where the plants grow. The sand separator must be emptied as needed, for example once a year. Excessive contamination of the growth layer with sand and some other particles can be avoided thanks to a sand separator. Instead of a sand separator, another filter specific for the material to be drained can be installed in another vessel upstream of the growth bed.

BRIEF DESCRIPTION OF THE DRAWINGS In order to provide a more complete understanding of certain embodiments of the present invention and their advantages, reference will now be made to the following descriptions taken in conjunction with the accompanying drawings. In the drawings: FIGURE 1 illustrates a schematic view of a stormwater treatment system in accordance with at least some embodiments of the present invention.

S & S EMBODIMENTS

Q I FIGURE 1 illustrates a schematic view of a system 1 for treating stormwater * 25 in accordance with at least some embodiments 3 of the present invention. The system 1 comprises a first vessel 2. The first vessel 2 acts as a N vessel, tank, box or basin into which liquid can flow over at least one side 12 of the rim 7 or rim of the first vessel 2 when the first vessel is placed in a pit in the ground. The first container 2 is typically arranged in a predetermined place, for example next to a parking area. The first vessel 2 is typically - located downstream of the surface from which the stormwater runoff is directed to the first vessel 2. That is, the first vessel 2 is typically arranged below the surface from which the stormwater runoff containing contaminants such as fine particles, metals, nutrients, chemicals and the like is directed to system 1. The first container 2 is at least partially filled with several layers of material, as described in more detail below. The runoff of stormwater flows by gravity through the filter medium. The system is to be understood as a flow-through system, ie the inlet water of the inlet is fed to the outlet as gravity by means of gravity.

The first vessel 2 typically has four side walls and a bottom. The volume of the first vessel 2 is selected using techniques known to those skilled in the art to process and bind a given stormwater feed to an otherwise sufficient amount. The dimensions of the first container can be, for example, 2400 mm x 1300 mm x 1200 mm. The material of the first container 2 is usually impermeable to liquids, but a number of openings can be made in the bottom of the first container 2 according to certain embodiments. The first vessel 2 can, for example, be made of a plastic material by injection molding or rotational molding. However, exemplary materials include plastic material, medium density polyethylene, high density polyethylene, steel, concrete, aluminum, fiberglass, or any other suitable durable material.

The system 1 further comprises a drain pipe 3 configured to be arranged inside the first container 2 in the first layer of material 4. The first layer of material 4 is typically arranged on the bottom of the first container 2 so that the drain pipe 3 is completely covered. The thickness S of the first material layer 4 can be, for example, 30 cm. The function of the first material layer 4 is to * collect “liquid N 25 - so that it enters the sewer pipe 3. The material S of the first material layer 4 can be, for example, gravel or small stones. The particle size or grain size of the material N of the first material layer 4 may be, for example, between 16 and 32 mm. The material of the first material layer 4 may also be, for example, gravel with a grain size X between 16 and 32 mm, together with 20% biochar with a grain size between 0-20 mm, s 30 or the material of the first material layer 4 may be Hekla & Pimpsten 5 (pumice granulate) with a grain size between 2-8 mm.

The second material layer 15 is arranged on top of the first material layer 4. The thickness of the second layer of material 15 may be, for example, 50 cm. The function of the second layer of material 15 is to filter the liquid which flows or flows through the second layer of material 15. That is, the second material layer 15 is configured - to filter the liquid flowing from the third material layer 6 to the first material layer 4. The material of the second material layer may be, for example, sand. The particle size or grain size of the material of the second material layer 15 may be, for example, between 0 and 16 mm. The material of the second material layer 15 can also be, for example, sand with a grain size between 0-16 mm, together with 20% biochar, with a grain size between 0-20 mm, or the material of the second material layer 15 can be Hekla® Rain bed (pumice granulate). The grain size of the first material of the first material layer 4 is typically larger than the grain size of the second material of the second material layer 15. The third material layer 6 is arranged on top of the second material layer 15. The thickness of the third material layer 6 can be, for example, 20 cm. The function of the third material layer 6 is to act as a biological nutrient medium for the plants grown in the first container 2. The third material layer can also be called the * growth layer ”. The material of the third material layer 6 can be, for example, surface soil. The material of the third material layer 6 can also be, for example, 40% sand with a grain size between 0-16 mm, together with 40% low fertility soil and 20% biochar with a grain size between 0-20 mm, or the material of the third material layer 6 can be Hekla ® Rain bed (pumice granulate). That is, the material of the second material layer 15 and the material of the third material layer 6 may be, for example, identical.

S N 25 There is a free space S 14 between the third layer of material 6 and the rim 7 of the first container. The height of the space 14 can be, for example, 20 cm. The space 14 in which the plants 19 can N grow acts as an additional space in the event of the first vessel 2 flooding. Plants 19 E participate in the purification by absorbing macronutrients and heavy metals. The 2 roots of the plants also help maintain the porosity of the soil. In addition, the plants provide 2 30 - ornamental green spot in urban environments. Plants are typically selected from S different shrubs, grasses or perennials. Typically, plants growing on beaches> are suitable. Plants should withstand periods of stagnant water, and should also tolerate drought. In addition, plants should be able to tolerate meltwater with road salt if necessary. It is recommended to use native plants as they have evolved to thrive in the local environment. Suitable plants can be selected together with, for example, landscape architects and / or garden centers.

In addition, the system 1 comprises a liquid overflow mechanism 5. The liquid overflow mechanism 5 typically comprises a T-shaped pipe connector 21, an overflow pipe 17 and a dome grille 18. The liquid overflow mechanism 5 is connected to a drain pipe 3 and an outlet pipe 9 and configured to be arranged inside a first vessel 2 from the material layer 4 through the second - material layer 15 and the third material layer 6 to the space 14 between the third material layer 6 and the rim 7 of the first container 2. The liquid overflow mechanism 5 is needed in case the liquid does not seep into the material layers 4, 15, 6 or does not seep into them quickly enough, which causes the space 14 between the third material layer 6 and the rim 7 of the first container 2 to flood. Liquid can enter - the liquid overflow mechanism 5 through the inlet 10 or a series of inlets in the dome grid 18 before the rising liquid level in the space 14 leaks over the rim 7 of the first vessel 2. The inlet 10 or inlet openings can be arranged, for example, 5 cm below the rim 7 of the first container 2. That is, the first inlet 10 of the liquid overflow mechanism 5 is provided in the space 14 between the third material layer 6 and the rim 7 of the first container 2. through a n-shaped pipe connector 21.

S N 25 - In addition, the system 1 comprises a first outlet 8 configured to be connected to the S outlet pipe 9 so that liquid flowing through at least one of the drain pipe 3 N and the liquid overflow mechanism 5 is directed outside the first vessel 2. E The diameter of the first outlet 8 can be, for example, 160 mm. The outlet pipe 9 is a pipe with a continuous outer surface or a pipe with a number of openings through the outer surface. 3 30 In other words, the filtered stormwater can be directed through a piping system to another O location, or the stormwater is allowed to seep into the ground. The diameter of the drain pipe 3 and the diameter of the outlet pipe 9 can be identical, for example.

According to certain embodiments of the present invention, the system 1 further comprises at least one second vessel 11, which is typically connected to at least one side 12 of the sides 7 of the rim 7 of the first vessel 2.

Said at least one second vessel 11 is typically placed close to the rim 7 of the first vessel 2 for pretreatment of incoming stormwater runoff.

Said at least one second vessel 11 comprises a second inlet 16 and at least one second outlet 12 through the wall 13 of the second vessel 11. That is, liquid is allowed to flow over the rim 7 of the first vessel 2 through an opening 16 in the second vessel 11 to the second vessel 11. 12 through which liquid can escape - from the second vessel 11 to the first vessel 2. said at least one second outlet 12 of the second vessel 11 is positioned so that the liquid is able to flow through said at least one second outlet 12 into the space 14 between the third material layer 6 and the rim 7 of the first vessel 2 .

Typically, the second vessel 11 comprises a plurality of adjacent outlets 12 in one wall 13 of the second vessel 11, thus providing a uniform flow of liquid to the first vessel 2. The adjacent outlets 12 are typically identical in dimensions and / or located at identical heights.

Typically, the outlets 12 are arranged some distance from the bottom of the second vessel 11.

Said at least one second vessel 11 is configured to collect material, for example sand, contained in the liquid flowing through the second vessel 11.

The second vessel 11 can - act - for example - as a sand separator. = In this way - excessive contamination of the third material layer 6, where the plants 19 grow, can be - avoided.

The second vessel 11 may, of course, comprise a particular filter for a particular contaminant or one may be included therein for pretreatment.

That is, the pretreatment device is arranged inside the first vessel 2 and connected to the first vessel 2. The pretreatment takes place S 25 - upstream of the filtration medium arranged in the first vessel 2. & O The dimensions of the second container 11 are typically selected so that one second container 11 or = an integer number of adjacent second containers 11 fits exactly one side of the rim 7 of the first container 2 between the two parallel> sides of the rim 7 of the first container 2.

The second vessels 11 can be connected to the first vessel 2 using x 30 - connection means such as screws, bolts, rivets, hooks and the like.

According to certain embodiments E, the second vessels 11 are connected to more than one side S of the first vessel 2.

It is to be understood that embodiments of the present invention are not limited to the particular structures, process steps, or materials disclosed herein, but also extend to their counterparts, as will be appreciated by one of ordinary skill in the art. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

Throughout this specification, reference to one embodiment or one embodiment means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, the occurrence of the terms * in one embodiment “or * in one embodiment” at different points in this specification may not all refer to the same embodiment. When reference is made to a numerical value using terms such as “about” or * substantially ”, the exact numerical value is also disclosed.

- As used herein, a number of objects, structural elements, composite elements and / or materials may be presented in a common list for simplicity. However, these lists should be construed as meaning that each member of the list is individually identifiable as a separate and individual member. Thus, no individual member of such a list should be construed as the actual equivalent of any other member of the same list - merely to present them in a common group without indication to the contrary. In addition, some embodiments and examples of the present invention may be referred to herein in conjunction with alternatives to their various components. It is to be understood that such embodiments, examples, and alternatives are not to be construed as actual counterparts of each other, but are to be considered as separate and N 25 independent embodiments of the present invention.

S o In addition, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Description N provides numerous precise details, such as examples of lengths, widths, S shapes, etc., to provide a thorough understanding of embodiments of the invention. However, one skilled in the art will recognize that the invention may be practiced without one or more precise details or with other methods, components, materials, and the like.

Known structures, materials, or procedures are not otherwise shown or described in detail so as not to obscure aspects of the invention. While the foregoing examples illustrate the principles of the present invention in one or more applications, it will be apparent to one of ordinary skill in the art that numerous changes may be made in the form, use, and details without departing from the inventor's capabilities and departing from the principles and concepts of the present invention. Accordingly, the invention is not intended to be limited, except as claimed below. The verbs comprising “and * includes” are used in this document as open constraints that do not exclude nor require the existence of features not mentioned herein. = The features mentioned in the dependent claims are freely combinable with each other, unless otherwise stated. In addition, it should be understood that the use of the singular form throughout this document does not preclude the plural form.

INDUSTRIAL APPLICABILITY Embodiments of the invention are industrially applicable in stormwater treatment.

REFERENCE NUMBER LIST 1 system

O

N O. . . N 2 first vessel © <Q 2 3 drain pipe = a 4 first layer of material 00

S + 5 fluid overflow mechanism

S

O S 25 6 third material layer 7 edging

8 first outlet 9 outlet pipe 10 first inlet 11 second vessel 12 second outlet 13 second vessel wall 14 space 15 second layer of material 16 second inlet 17 overflow pipe 18 dome grille 19 plants 20 bottom of first vessel 21 pipe connector oO

N Oo

N © Q @ o

OF

T and m o 0 + oO +

O

N Oo

N =

Claims (12)

PROTECTIVE REQUIREMENTS A system (1) for treating stormwater, the system (1) comprising: - a first vessel (2), - at least one drain pipe (3) configured to be arranged into the first vessel (2) in a first material layer (4 ), and - at least one liquid flood mechanism (5) coupled to said at least one drain pipe (3) and configured to be arranged in the first vessel (2) in such a way that it extends from the first material layer (4) through a second material layer (15) and a third material layer (6) to a space (14) between the third material layer (6) and an edge (7) of the first vessel (2), in which space at least one inlet opening (10) of the said at least one liquid flooding mechanism (5) is arranged, characterized by at least a first outlet opening (8) configured to be connected to at least one outlet pipe (9) in such a way that a liquid flowing through at least one of the said at least one the drain pipe (3) and the said at least one the liquid flood mechanism (5) is led to the outside of the first vessel (2). System (1) according to claim 1, characterized in that the liquid flood mechanism (5) comprises a T-shaped pipe connection (21), a flood pipe (17) and a structure (18), which is configured to sound the liquid flows S into the flood pipe (17). 8 Q = E 25 System (1) according to any one of the protection claims 1-2, characterized in that at least one second vessel (11) is connected to at least one side (12) of the sides of SC 3 the edge (7) of the first vessel (2). :> System (1) according to claim 3, characterized in that the at least one second vessel (11) comprises a second inlet opening (16) and at least one second outlet opening (12) through the wall (13) of the second vessel (11). System (1) according to claim 4, characterized in that said at least one second outlet opening (12) is arranged in such a way that liquid can flow through said at least one second outlet opening (12) into the space ( 14) between the third material layer (6) and the edge (7) of the first vessel (2). System (1) according to any one of claims 3-5, characterized in that said at least one second vessel (11) is configured to collect material contained in the liquid flowing through the second vessel (11). System (1) according to any one of the protection claims 3-6, characterized in that said at least one second vessel (11) is configured to remove sand from the liquid flowing through the second vessel (11). 2 System (1) according to any one of claims 1-7, characterized in that the N second material layer (15) is configured to filter liquid flowing from the S third material layer (6) to the first material layer (4) . N x a x System (1) according to any one of the protection claims 1-8, characterized in that a s first granule size of a first material in the first material layer (4) is larger than a second granule size of a second material in the second material layer (15). System (1) according to any one of the protection claims 1-9, characterized in that said at least one outlet pipe (9) consists of a pipe with a continuous outer surface or of a pipe with a plurality of openings through the outer surface. System (1) according to any one of the protection claims 1-10, characterized in that a first diameter of said at least one drain pipe (3) and a second diameter of said at least one outlet pipe (9) are identical. System (1) according to one of the protection claims 1-11, characterized in that the system is configured to allow at least one additional filter layer to be arranged in the first vessel (2). O N O N O O O N I a a 00 + O + O N O N>