RAINWATER TREATMENT PLANT

Description

[0001] The invention relates to an underground rainwater treatment plant installed in the ground.

[0002] The desire for an undiminished retention volume and / or a permanently functional infiltration system is massively counteracted by the sediments and pollutants introduced into the water, which has always resulted in efforts to free the inflow as far as possible from these substances, which inevitably lead in infiltration systems sooner or later to a so-called self-sealing of the infiltration areas (internal colmation) with the introduced substances or their transformation products.

[0003] This leads to increasing functional impairments over the course of the service life, particularly in the case of conventional infiltration trenches which have been known for many years and are mostly made of 8 / 16 or 16 / 32 mm filter gravel, when rainwater is infiltrated, as the drainage pipe in these infiltration trenches is usually placed centrally in the storage body which is similar to a pipe trench. This means that the sediments introduced into the storage body begin to settle under the drainage pipe, thus increasingly sealing the infiltration base and with further sediment input this sealing of the infiltration areas on the sides of the infiltration trench progresses until after a few years the infiltration trench is completely sealed and is therefore no longer functional.

[0004] The mostly central position of the drainage pipe in relation to the infiltration trench height also prevents effective cleaning of the infiltration trench, since all sediments stored in the gravel under the drainage pipe can no longer be flushed out.

[0005] If a drainage pipe is present as an inflow organ, its water-permeable slits usually prevent the penetration of substances with a diameter of more than 2.5 mm.

[0006] However, even here it is not possible to prevent the entry of pollutants dissolved in the water into the storage tank, which, due to microorganic degradation processes in the storage body itself, form conversion residues, so-called biomass from the residues of microorganisms, which, following gravity, increasingly settle on the storage or infiltration base and, over a significantly longer period of time, as is usual with previous infiltration systems, nevertheless inevitably lead to self-sealing and / or reduction of the storage space.

[0007] The amount of substances that settle here depends on the amount of pollutants introduced and the hydraulic behavior of the reservoir, which, for example, leaves the microorganisms little time to form biomass if it is filled and discharged quickly.

[0008] However, the short residence time also hinders the purification of the water, so that it may leave the system with the same level of pollution as it was when it was previously impounded, which pollutes the environment, particularly in systems that infiltrate directly above the bottom of the infiltration trench.

[0009] In order to achieve the greatest possible retention of negative inputs into the storage or infiltration system, unfortunately, systems are required that would be in no way inferior to the size of the storage body and / or the infiltration facility, which is particularly evident in the large settling tanks of municipal or large-scale industrial stormwater treatment plants.

[0010] In order to avoid the resulting costs escalating, the current treatment systems are only able to extend the service life of infiltration systems to a limited extent due to the limited retention of sediments in upstream shaft systems.

[0011] In recent years, various possibilities have become known from the state of the art for processing or treating rainwater that is to be discharged or flowing into sewers, storage or infiltration trenches and which may be heavily polluted in various ways, particularly in an ecological manner, so that it no longer harms the environment or can be reused, for example, as process water.

[0012] It has been known for decades that rainwater can be cleaned in a simple and efficient way using the so-called living soil zone, which is usually formed from the naturally occurring, microorganism-active topsoil, in which the polluted water is cleaned, in particular by the microorganisms, as it seeps through.

[0013] In addition, before seepage onto the surface, sediments and coarse contaminants are filtered out via the filtering effect of the soil.

[0014] For many years, stormwater treatment or sedimentation basins have been used as large concrete structures in municipal or large-scale industrial applications for the separation, or more precisely sedimentation, of particulate substances carried in water, to which pollutants such as heavy metals and the like often adhere.

[0015] Fränkische Rohrwerke, among others, has developed a modularly formed fill infiltration system (Rigo-Fill) consisting of numerous plastic mesh boxes. Water introduced via pipes is impounded and then seeps into the underlying soil layers. Because the flat infiltration system base is inaccessible and therefore not flushable due to the plastic mesh, a sedimentation pipe (Sedi-Pipe) with a diameter expanded to the normal sewer diameter is used for preventative sediment control. This pipe reduces the flow velocity to below 0.05 m / s, thus contributing to the settling of a large portion of the sediment.

[0016] According to the supplier Fränkischen Rohrwerke, among others, these systems can be supplemented with very expensive filter units (Sedi-Substrator), which are replaced at intervals and consist mainly of minerals that are supposed to be able to sufficiently remove light liquids and other remaining pollutants from the seeping water.

[0017] Furthermore, European patent EP 0 938 615 discloses a multi-layered floor surface for the disposal of rainwater, among other things. Water is supplied to and drained from the highly load-bearing, porous gravel installed within a soil sealing trough via at least one drainage pipe resting on the sealing layer. Rinsing and microorganic processes are provided for cleaning.

[0018] European patent application EP 01913561.5 discloses an infiltration system that is largely integrated into the superstructure of traffic areas. The water introduced via drainage pipes seeps into the underlying soil, particularly through the extensive base of the infiltration system. The sediments introduced are intended to remain largely on both sides of the drainage pipe resting on the base of the lower pipe trench, from where they can be flushed out as needed.

[0019] Companies such as Eurofiltrator and Intewa have developed half-shells in the form of polygons made of plastic for the creation of chamber or tunnel systems combined with gravel overlays to form infiltration systems with increased storage volumes. These systems also provide preventive protection against internal clogging only in the inflow area upstream of the actual reservoir.

[0020] Mall-Beton offers concrete cisterns with a perforated concrete wall as an infiltration system in the cistern area above the domestic and / or firefighting water supply. This system stores rainwater by continuously impounding it in the lower area and allows excess water to seep into the surrounding soil in the upper area. These systems also only require cleaning upstream of the storage tank, e.g., via centrifugal separators (cyclones).

[0021] Several other manufacturers (e.g., Funke Kunststoffe, Betonwerke B. Müller) have developed treatment systems that, when installed at the edge of traffic areas, clean the runoff from rainwater of sediment and pollutants through artificial trough replacement systems (filter substrates) optimized for infiltration, and then allow them to seep into the ground. The substrate must be replaced with new substrate after it has become saturated with sediment or pollutants.

[0022] From EP 0 70000 19.5, a rainwater purification system that can be integrated into water storage and / or infiltration systems made of storage mineral or plastic modules is known, which, in addition to the physical filter, sedimentation and settling systems made of fleece and / or foil arranged in the storage mineral, in a further embodiment integrates natural purification processes into the drainage systems.

[0023] In addition to the physical processes for settling and / or filtration integrated into the storage and / or infiltration bodies, adsorption and / or precipitation, ion exchange and / or biological degradation, etc. of pollutants are also possible.

[0024] This potentially broad purification spectrum is preferably achieved by means of a granulate with a large surface area (e.g. lava, pumice, activated carbon, fibers, grit, sand, etc.) that can be additionally introduced into the infiltration trenches and / or placed underneath them, which should serve as a carrier for natural purification media and / or as a colonization space for microorganisms for the desired purification stages.

[0025] Alternatively, the granulate forming the storage or drainage ditch can be mixed directly with a material suitable for this purpose, which can be particularly useful because crushed granulate made from natural rock provides a surface that is easily colonized by microorganisms or that adheres well to appropriate nutrient or cleaning solutions.

[0026] However, the purification components can also be introduced into the reservoir or the infiltration trench via, for example, fibers or microtubes mixed into the storage mineral of the reservoir or the infiltration trench.

[0027] In the case of infiltration trenches, underlying granulate can also be formed directly from topsoil suitable for infiltration basins.

[0028] In the following, it should be noted that in addition to Fränkische Rohrwerke, various other suppliers also offer storage modules made of plastic, some of which are also designed with a tunnel with a water-permeable wall running longitudinally through the storage module.

[0029] These components are equivalent to conventional infiltration trenches, formed from storage mineral and drainage pipe, in terms of construction and function and are therefore, in addition to the usual plastic modules without tunnels, also suitable for equipment with the above technology and the invention of a modular rainwater treatment system discussed here.

[0030] Chamber or tunnel systems made of plastic half-shells, such as those offered by Eurofiltrator or Intewa, are also suitable for equipping with the treatment system.

[0031] In addition to these most widely used techniques, there are also comparable functionalities of storage tanks and infiltration trenches made of concrete or metal (in pipe or box construction), which are equally suitable for accommodating or integrating at least one of the treatment stages that can be combined with each other.

[0032] However, in order not to have to describe the invention in all facets for the different storage components (storage mineral, plastic, concrete, etc.), this description is largely limited to an integration of the treatment plant in storage mineral, without thereby excluding the aforementioned other fields of application in plastic modules, concrete, metal or other materials.

[0033] The object of this invention is to replicate cleaning processes from bionic and / or physical and / or chemical processes or cleaning components depending on the cleaning requirements and to carry them out either as only one cleaning stage according to the invention or in conjunction with others and, if necessary, to combine or supplement them sensibly with upstream or downstream cleaning systems.

[0034] The treatment plants according to the invention are accordingly preferably designed to be composed of at least one, but if necessary, of various cleaning stages or components according to the invention, and preferably to be matched to the expected dirt load.

[0035] The invention is therefore based on the object of creating a treatment plant to be arranged in front of and / or within a sewer network or a storage body formed from plastic, concrete, metal components and / or bulk materials, which, depending on the selection of components, enables partial to extensive treatment or conversion by separation, filtration, precipitation and / or microorganic or chemical treatment of the sediments, suspended matter and / or other pollutants flowing in with the water, before a functional restriction of the downstream drainage system, possibly used process water or even environmental pollution can occur.

[0036] The following treatment components can be considered according to the invention, which can be combined individually or with one another: 1. Sludge traps for settling coarse contaminants, 2. Sedimentation systems for sedimenting even the lightest suspended solids, 3. Single-stage to multi-stage filters made of e.g. geotextiles, filter fleeces, perforated sheets, sintered metals, foam and the like, 4. Baffles for gravity separation of light liquids, 5. Coalescence separators for separation of light liquids 6. and (bionic) filter substrates in all conceivable compositions adapted to the expected contaminant load.

[0037] The central component in or around which the rainwater treatments according to the invention take place is a drainage pipe or a drainage element that can be made from round or square pipes as well as from cubic or polygonal components that can be made from all conceivable building materials from concrete to plastic.

[0038] In the case of cubic components (e.g. Rigo-Fill), it can make sense to manufacture the treatment plant from many cubic components to a size appropriate to the requirements and to place it, for example, outside, to the side or in the middle of an infiltration trench or water reservoir made of bulk material and / or plastic, to transport the water there via sewer lines and to clean it in the treatment plant and then to allow it to flow into the actual trench or reservoir.

[0039] To create a correspondingly efficient treatment plant, several treatment plants according to the invention can also be integrated into a storage or infiltration body.

[0040] When connected in series, these treatment plants can be equipped with identical or different treatment processes.

[0041] It may also be useful to divide the treatment plant into several cleaning steps, which may be divided, for example, into a possibly combined treatment plant in the inflow area and a possibly combined treatment plant in the outflow.

[0042] The treatment systems in the inflow and outflow can be arranged parallel to each other or in series. Any arrangement of the two treatment systems within the reservoir or infiltration trench is also conceivable.

[0043] If the two treatment systems are spatially separated within the storage medium, the space through which the water flows from one treatment system to the next can be equipped for further cleaning, e.g. with filter fleece or filter substrates.

[0044] In most cases, the treatment plants will be connected to shaft structures at both the inflow and outflow, which may also contain treatment stages themselves.

[0045] It would therefore not be unusual to integrate at least one of the conventional and state-of-the-art cleaning processes into the inflow and / or outflow of the treatment plants according to the invention.

[0046] However, it is also possible to operate the treatment plant without a shaft structure in the inlet and / or outlet in direct connection to the inlet and / or outlet sewer line.

[0047] In the drainage of roads, for example, such a treatment plant according to the invention is mostly used primarily for the sedimentation of coarse to very small sediments and for the retention of light liquids.

[0048] In order to achieve sediment separation, it is necessary to reduce the flow velocity and create the largest possible water surface area so that the strong, largely horizontal flow of water coming from the pipeline is reduced and the substances can settle due to the flow, which is generally reduced by the specialist to <0.05 m / s.

[0049] In addition, it is important to ensure that the settling distances and times are kept as short as possible so that even the smallest sediments can settle and cannot be carried out of the system with the water beforehand.

[0050] According to the invention, the flow reduction is preferably achieved by a large floor area and / or a cross-section exceeding the hydraulic requirements, the drain line or the cube.

[0051] Particularly with the help of drain pipes, large cross-sections can be easily achieved to massively reduce flow, since the water escaping from the drain pipes over the often long length of the drain pipe moves out of the drain pipe on both sides transversely to the drain pipe and is thereby extremely slowed down in its flow.

[0052] The components to be used for the construction of the sedimentation plant consist in particular of slotted drain pipes of any cross-section and / or slotted half-shells (Eurofiltrator, Intewa) and / or cubic infiltration fills consisting of an open grid structure (Rigo-Fill from Fränkische Rohrwerke), which can also be equipped with a tunnel (Rigo-Fill-Inspect from Fränkische Rohrwerke).

[0053] If a flow reduction according to the invention is to be carried out in a cubic component, this is preferably to be formed as a concrete or steel container or from plastic blocks, which can also be arranged horizontally and / or vertically to form larger cross sections.

[0054] In addition to installation in a surrounding storage medium made of storage mineral, plastic modules, concrete or metal, the modular treatment plant can also be installed in a pipe surrounding it.

[0055] If the treatment plant is installed in a sewer line as a storage medium, this casing pipe must be made tight against water leakage and connected to the downstream sewer, storage tank or drainage ditch by means of a drain pipe.

[0056] In such cases, the sealing of the treatment plant can also be achieved by means of an additional structure, which can be made of concrete, metal or plastic, for example as a jacket pipe or a square container.

[0057] The treatment plant, designed as a pipe or cube, is capable of enabling a significant separation of sediments from the inflowing water simply through its base areas and / or cross-sectional enlargement.

[0058] Now, recent research has led to the realization that this sedimentation is not able to remove the most critical substances from the water, since these sediments adhere to the particles with a diameter of less than 60 µm and can therefore only be retained to a limited extent with simple sedimentation.

[0059] One way to optimize sedimentation is to introduce lamella packs formed from stacked lamella blades within the treatment plant.

[0060] For this purpose, there are usually at least one to several lamella packs arranged one behind the other in the direction of flow.

[0061] If the water flows towards these, the water is deflected upwards via the lamellae arranged one above the other and preferably rising upwards. Due to the greater density of the sediments compared to the water, the sediments move more quickly towards the lamellae and can settle on the lamellae.

[0062] The more densely the individual lamellae are arranged on top of each other, the shorter the settling path of the sediment from the water.

[0063] Likewise, a long overflow path over the lamella blade can promote settling.

[0064] Close lamella spacing and a long overflow path with lamella blades positioned against the flow therefore result in improved separation performance.

[0065] The inclined position of the lamella blades also results in a self-cleaning process, as the separated sediments slide down the lamella blade when the flow decreases and from there, during the period when there is no further inflow, can sink or fall down into the settling space that is usually present.

[0066] This self-cleaning effect is further enhanced in permanently dammed, non-drying lamella packs by preventing sediment from drying out and encrusting on the lamella blades. The sliding of sediment from the lamella blades can also be facilitated by providing them with a lotus effect, which can prevent any substances from adhering to them.

[0067] The optimum cleaning performance for separation and sedimentation can be achieved if, in addition to the above measures, the residence time in the treatment plant is extended as long as possible in order to allow even the smallest sediments to settle.

[0068] However, even sedimentation via lamella packs does not usually result in sufficient separation of the potentially highly contaminated micro-sediments.

[0069] This is only possible through filtration using appropriate filter fleeces or filter substrates.

[0070] The simplest filters can be created using geotextiles, or better still, filter fleece.

[0071] Filter-stable tiles for various filter stages are already known from infiltration trench construction or similar applications as separation or trickle protection fleece between or within the infiltration trench and adjacent soil layers.

[0072] Deviating from this known application in infiltration trench construction, which is generally not about filtering but primarily about preventing soil from entering the infiltration trench from the edge area, this invention provides for the integration of the filter fleece into the treatment plant.

[0073] In a first embodiment, the filter fleece is to be provided as the last treatment stage before the water leaves the treatment plant and flows into the storage tank or the drainage ditch.

[0074] For example, it can be arranged using appropriate brackets or devices with a pre-measured distance to the drain cross-sections in the treatment plant.

[0075] Likewise, as a supplement to lamella packs, it can enclose them at the lateral edge, e.g. in the direction of flow, and thus only filter water that has already sedimented there and above and then allow it to flow out of the treatment plant.

[0076] If there is no risk of the treatment plant becoming self-sealed, the filter fleece can also be arranged directly in front of or behind the outflow cross-sections of the treatment plant, which means that the filter fleece can also be in contact with the outer wall of the treatment plant.

[0077] Since filters tend to build up a filter cake consisting of filtered material on the flow side, care must be taken to ensure that this does not lead to a blockage of the drain.

[0078] To counteract this, the filter fleeces must be arranged, for example, at an appropriate distance from the drainage cross-sections (e.g. drain pipe slits or drain pipe connection) so that a sufficient filter fleece passage over the size of the filter fleece surface remains for as long as possible and the space behind the filter fleece is sufficient to allow the water penetrating the large filter fleece surface to reach the drainage cross-sections in the required quantity.

[0079] In order to maintain the functionality of the system in the other treatment steps even when the filter fleece is completely sealed or during heavy rainfall events, the filter fleeces can be equipped with overflow relief valves at appropriate locations, which can direct the water that does not penetrate the filter fleece unfiltered within the treatment system or out of it via these overflow relief valves.

[0080] To prevent this from happening, these overflow relief devices can be designed to either have a hydraulically reduced cross-section or to react hydrostatically to higher pressure.

[0081] The hydraulic effectiveness can also be increased by installing the filter fleece in a back-and-forth zigzag pattern into the drainage system to increase the surface area, as is known, for example, from air filters in automobiles.

[0082] In order to achieve the most comprehensive filtration possible, not only of the sediments but also of the suspended matter from the water, it can be sensible to arrange not just one filter fleece, but several filter fleeces of different filter stages one after the other in the direction of flow within the treatment plant at a certain distance, whereby the filter stages in the direction of flow can filter out increasingly finer sediments up to the point of suspended matter filtration.

[0083] In another embodiment, this multi-stage filter process can also be integrated into just one, but correspondingly thick, or multi-layered filter fleece without any intermediate spacing.

[0084] In order to remove the filter cake when the filter tiles are increasingly sealed, a pressure flushing process can be used from the outside and / or a suction flushing process from the inside against the operational flow direction to remove the filter cake and / or the filter fleeces can be provided as replaceable individual elements in the treatment plant, for example to remove them from the plant, clean them outside and then reinsert them into the plant.

[0085] Regardless of how the treatment system operates as a filter and / or settling device, sediments remain in increasing quantities in the storage space of the treatment plant and reduce it accordingly.

[0086] Therefore, for long-term functionality, it is essential to periodically flush the sediment out of the system and vacuum it out of an inspection structure connected to the system. To make this cleaning process efficient, the treatment systems should preferably be designed so that the sediment can be removed quickly and easily using conventional flushing technology used in sewer cleaning.

[0087] The previously described treatment processes and assemblies according to the invention were limited exclusively to the retention of sediments and suspended matter.

[0088] However, these represent only a portion of the potential pollutants. From an environmental perspective, pollutants dissolved in water or adhering to the smallest sediment, such as hydrocarbons and heavy metals, which can originate not only from traffic runoff but also from metal roofs, are more critical.

[0089] For a long time, these pollutants could only be filtered out via the naturally living soil zone of a surface infiltration basin or, in recent years, via filter substrates, which are increasingly being used in roadside gutters or underground shafts and are offered in particular as replaceable filter substrate fills or filter substrate cartridges.

[0090] In a further embodiment of the invention, the natural functioning of the degradation of the remaining pollutants is to be simulated as far as possible or necessary inside and outside the treatment plant.

[0091] In addition to the physical processes already mentioned, such as settling and / or filtration, adsorption and / or precipitation, ion exchange and / or biological degradation, etc. of pollutants are desired and also possible with the subject matter of the invention.

[0092] This potentially broad purification spectrum should preferably be achieved by means of a filter substrate that can be additionally introduced into the treatment plants and which, among other things, should serve as a carrier and / or microorganic colonization space for the desired purification steps.

[0093] The integration of the filter substrates into the treatment plant takes place in separate, preferably dismantled for inspection purposes, manageable components into which the filter substrate can be inserted as loose bulk material or as dimensionally stable blocks.

[0094] For filter substrates made of bulk material, appropriate components must always be provided which can accommodate the filter bulk material in the appropriate thickness and area.

[0095] If the filter substrates are manufactured in dimensionally stable filter blocks or cartridges, their dimensions can be designed in such a way that they can be inserted directly into the treatment plant without any additional components.

[0096] For all shapes of filter substrates, regardless of whether they are loose or rigid, it is important to ensure that the water flowing through them can seep through an optimal filter path in the filter substrate.

[0097] Since the filter substrates will also become increasingly self-sealing, all of the steps already listed for filter fleeces to ensure their functionality also apply here, including an overflow relief device that can be integrated into these components, regardless of how this may sensibly look.

[0098] While all treatment steps have so far been largely limited to the interior of the system, this does not apply to the filter substrates.

[0099] These can be arranged alone or in combination with integrated filter substrates or other treatment stages, also within or below the storage medium, regardless of whether this is made of storage mineral, plastic modules, concrete or metal components.

[0100] In block construction, the filter substrates, with sufficient strength, can also serve as a component that completely or partially supports the storage medium and independently bears the resulting surface and traffic loads.

[0101] The filter substrate integrated into the storage medium should preferably be arranged in or under the storage tank so that it is exposed to the water inflow as evenly as possible.

[0102] The arrangement of the upstream treatment plant, which in this case usually serves as an inflow organ, can also be arranged deeper than the filter substrate if this part of the treatment plant is formed, for example, by a drain pipe that is located in a drain pipe trench below the infiltration level of the storage tank.

[0103] However, with such a design, the filter substrate will usually have its apex at the level of the deepest drain pipe slots or the drain pipe bottom.

[0104] The drainage systems from the treatment plant into the storage medium can also be arranged well above the filter substrate.

[0105] Prior sedimentation should always be provided.

[0106] If the filter substrates are not self-regenerating, prior treatment via filtration, separation or further treatment steps is recommended.

[0107] As with the lamella packs, the filter fleece can be arranged in front of or behind the filter substrate in the direction of flow, depending on the filtering effect.

[0108] Filter fleece arranged in front of the filter substrate serves in particular to extend the service life of the filter substrate, since the filter fleece can already retain many pollutants that would otherwise have had to be separated by the filter substrate.

[0109] Filter fleece arranged behind the filter substrate prevents, among other things, the discharge of degradation products from the filter substrate into the downstream plant areas or the natural soil that is worth protecting.

[0110] In order to enable the filter substrates, especially the microorganic cleaning processes, to achieve good cleaning performance, a good air supply is also recommended, since if there is too little or no air exchange, the more active aerobic microorganic decomposition processes can turn into anaerobic processes, which are not only less effective but can also be accompanied by unpleasant foul odors.

[0111] If the air supply in the treatment plant does not already provide sufficient air supply for aerobic processes, air exchange can also be ensured by additional ventilation devices, which can also serve a dual function as rinsing devices for the treatment stage or even the entire treatment plant.

[0112] These can be led from the treatment plant into the adjacent shafts and, due to their structural design, react to the air passing over them in such a way that a permanent air exchange is possible, if possible throughout the entire treatment plant.

[0113] However, the air exchange will usually be sufficient due to the pumping effect of water retention (used air is pushed out of the system) and drainage (fresh ambient air is sucked in).

[0114] In addition to the drains that need to be cleaned, for example from metal roofs, the treatment plants also regularly have to deal with light liquids flowing over the surface from normal leakages from motor vehicles as well as large quantities of pollutants from accidents.

[0115] The usual vehicle leaks usually adhere to the washed-in sediments and must therefore be contained by the filter substrates at the latest.

[0116] However, with larger inflows of light liquids, these would be immediately overwhelmed and would also become unusable, requiring replacement. The untreated light liquid then flowing out of the system would subsequently contaminate deeper soil layers, which has always been avoided in such cases with gully infiltration systems.

[0117] It is therefore provided in a further embodiment of the invention that the treatment plants can also be equipped with light liquid separators, preferably as coalescence separators.

[0118] Since these would have to be used especially in the event of accidents, it is advisable to arrange them preferably between the sedimentation and the filter systems made of filter fleece and / or filter substrates, if such cleaning components are to be integrated into the treatment plant.

[0119] Of course, the treatment plant can also consist of only light liquid separation or a combination of sedimentation and light liquid separation.

[0120] The simplest form of light liquid separation is achieved by gravity. It is therefore sufficient to relocate the water outlet from the treatment plant below the apex of the plant to create a reservoir for floating light liquid between the water outlet and the apex, similar to the functional principle of a baffle. This liquid can then be disposed of separately via a drain located at the apex.

[0121] This simple design can be upgraded to a coalescence separator with a coalescer arranged in the inflow to the plant crown.

[0122] The coalescer can be constructed in all currently common designs, e.g., open-pore plastic, stainless steel wool, stacked slats, etc. It can be positioned vertically, inclined, or horizontally, with the flow approaching from below appearing to offer the most advantages, as this method allows for the easy construction of large coalescers in elongated and / or wide treatment plants with limited installation depth.

[0123] These can also be separated into easy-to-assemble sizes, which can be combined to form units of any size in the treatment plants.

[0124] To separate light liquid separation and filtration, the system components must be connected in series, which can be supported by additional bulkheads, for example, under which only oil-free water flows.

[0125] It goes without saying that the system-integrated light liquid separators according to the invention can be upgraded as required with today's standard additional components such as self-closing valves when fully filled, sampling options and the like.

[0126] If the treatment plant is used in critical areas, e.g. the chemical industry, greater precautionary measures are often required, which prohibit leaving the water to the treatment plant to its own devices.

[0127] In such cases, it will make sense to encapsulate the entire system, i.e. to enclose it, and to allow drainage only via a drain line, which can be closed in the event of damage with a valve that reacts manually or automatically to, for example, harmful substances in the incoming or outgoing water.

[0128] The probably most common direct integration of the treatment plant within the storage tank and / or infiltration trenches with the cleaning process according to the invention, which can be freely combined from at least one to many cleaning stages, not only allows for the dispensing with the known separation, sedimentation and / or filter assemblies and / or trough infiltration systems upstream or downstream of the storage tank and infiltration trenches, but also allows for an optimization of the cleaning process with simple means due to the compact, high-performance treatment plants that can be manufactured in this way, in most cases easily.

[0129] The drawings show several embodiments of the invention in sections.

[0130] The examples given are based on only one supply line into a concrete shaft and only one sedimentation line, which here is formed from a round drainage pipe.

[0131] Likewise, several supply lines could be connected in this concrete shaft and several sedimentation lines with possibly different cross-sections (large, small and / or round, cubic, oval, polygonal, etc.) could branch off from it, whereby inflow lines could also be connected to these sedimentation lines via branches or saddles.

[0132] The representation of components outside the drain pipe, e.g. storage medium integrated filter substrates, was omitted due to the detailed description.

[0133] The sample selection shown shows in Fig. 1Treatment plant for sedimentation in cross section Fig. 2Treatment plant from Fig. 1 in horizontal section Fig. 3Treatment plant from Fig. 1 with additional lamella sedimentation in cross section Fig. 4Treatment plant from Fig. 3 in horizontal section Fig. 5Treatment plant similar Fig. 1 with additional coalescer as light liquid separator in cross section Fig. 6Treatment plant from Fig. 5 in horizontal section Fig. 7Treatment plant from Fig. 1 with additional filter substrate segments in cross section Fig. 8Treatment plant from Fig. 7 in horizontal section Fig. 9Treatment plant from Fig. 1 with additional shaft-integrated pre-cleaning for coarse sediments and light liquids as well as additional lamella sedimentation and filter substrate segments in cross-section Fig. 10Sedimentation plant from Fig. 9 in horizontal section

[0134] For all sectional views, components above the section plane are generally shown in dash-dotted lines.

[0135] The cutting planes can be offset from each other.

[0136] In Figure 1 a treatment plant (10) is shown, which is equipped with a concrete shaft (23) and the primary sedimentation plant (11) in the form of a drain pipe (12) provided with a drain pipe slit (13) only over the pipe center (17).

[0137] In this example, the concrete shaft (23) upstream of the sedimentation plant (11) can also be used as a secondary settling chamber (20) for coarse sediments.

[0138] In the upper area of ​​the concrete shaft (23) there is an inspection opening (22) to access the concrete shaft (23), the supply concrete pipe (19) as well as the sedimentation system (11) for maintenance and cleaning purposes.

[0139] The sedimentation system (11) operates in a continuous flow mode. This means that the sediment flushed into the concrete shaft (23) and sedimentation system (11) remains as water-saturated sludge below the invert level (17) in a water bath extending down to the concrete pipe invert (18) or invert level (17). The drain pipe slits (13) located in the upper area of ​​the drain pipe (12) also extend, with their deepest slots (13), only down to the invert level (17), thus ensuring complete emptying of the inflow via the concrete pipe (19) via the drain pipe slits (13) at the invert level.

[0140] Due to the large diameter, the semi-circular cross-section remaining above the invert (17) in the drain pipe (12) is almost identical to the fully circular cross-section of the smaller diameter concrete pipe (19) in order to ensure a backflow-free inflow from the concrete pipe (19) via the concrete shaft (23) into the sedimentation system (11).

[0141] Sediment flowing in with the water via the concrete pipe (19) separates from coarse sediments already in the concrete shaft (19) and allows them to grow progressively upwards above the shaft bottom (21) in the settling chamber (20) of the concrete shaft (23).

[0142] Lighter sediments are transported via the current to the sedimentation system (11).

[0143] The cross-section and length of the sedimentation system (11) lead to a significant slowing of the flow, which, according to some technical reports, should not exceed a value of, for example, 0.05 m / s for sedimentation. Overall, however, the optimal flow velocity for this invention depends on the intended purification performance and should therefore preferably be determined on a system-specific basis.

[0144] As a result, the degree of settling capacity used as a basis for the sedimentation system (11) ensures the appropriate system size in order to allow the sediments, depending on their grain size, the appropriate time to sink into the settling area (15) of the drain pipe (12).

[0145] Figure 2 provides the information in advance Figure 1 described treatment plant in a height-shifted horizontal section.

[0146] Coming from the left in the inflow direction, the supply line from a concrete pipe (19) is shown, connected to the square cross-section of the concrete shaft (23) with settling chamber (20) and the inspection opening (22) located above the cutting plane.

[0147] In the inflow direction on the left, a sedimentation system (11) designed as a drain pipe (12) is connected to the concrete shaft (23) in a shaft lining (26).

[0148] The drain pipe (12) is constructed from a multi-layer PEHD pipe, which is provided with circumferential, corrugated stiffening ribs (24) for stabilization. The multi-layer design of the drain pipe (12) also ensures that the drain pipe's inner wall (25) can be constructed as a smooth and highly washable pipe wall.

[0149] Above the section plane of the drain pipe (12), the drain pipe slits (13) can be seen, which in this example are evenly distributed over the upper half of the drain pipe (12) as well as along its length. Drain pipe slits (13) deviating from this even distribution may also be required depending on the task, see Figure 5 .

[0150] Figure 3shows one of the many complementary or combinable additional treatment processes or components that can be integrated into the sedimentation system (11). It depicts a lamella separator formed from many individual lamella packs (43) which, if not already permanently installed in the drain pipe (12) during installation, can also be inserted in a mobile manner through the inspection opening (22) into the concrete shaft (23) and from there, via the rails (30) on both sides, one after the other into the drain pipe (12). This would also enable sporadic basic cleaning of the lamella packs.

[0151] In this example, the lamella packs (43) are formed from approximately 25 cm long lamella blades (44) that rise at an angle of 60° from the inflow and are arranged 2 cm above one another. This results in a considerable increase in the surface area used for sedimentation, particularly for very small sediments, since the sediments only have to travel a maximum of 2 cm from lamella blade (44) to lamella blade (44) until they settle and can temporarily adhere to the lamella blades (44) before they are later pushed as larger clusters by the flow over the rear edge of the lamella blades (44) in the direction of flow and sink down into the settling area (15) of the sedimentation system (11).

[0152] The partially purified water reaches a transition area (45) behind the lamella blades (44) up to the next lamella blades (44) arranged one above the other, where the settling process of the sediments still in the water begins again.

[0153] If the water flow cannot already move laterally in partial flows from the lamella pack (43) in the direction of the lateral transition area (45) to the drain pipe slit (13) out of the lamella packs (43), a water transition to the drain pipe slit (13) is present at the latest at the end of a closed section consisting of several lamella packs (43).

[0154] Figure 4 shows in horizontal section in addition to Figure 2 the lamella packs (43) integrated into the drain pipe (12), which lie firmly against one another with their end faces at the pack joints (35).

[0155] The transition areas (45) between the spaced-apart lamellae (44) or the lamella packs (43) and the drain pipe (12) are also shown. A representation of the Figure 1 and 2 The identical drain pipe slitting (13) has been omitted here to avoid any confusion.

[0156] Figure 5 shows another of the many complementary and combinable treatment processes or components that can be integrated into the sedimentation plant (11).

[0157] A coalescence separator is shown, consisting of a sealed half-shell (46) with a liquid-permeable coalescer (40) arranged at the apex. The coalescer can be made of lamellae, open-pore plastic, or any other suitable material.

[0158] Light liquid carried in with the water must pass through this in order to reach the drain pipe slot (13).

[0159] The simple functional principle of coalescence by promoting the merging of colloidal particles, e.g. many small oil droplets that accumulate to form a larger one, which thus gains buoyancy and can rise in the water, causes a significant reduction in the amount of oil carried by water in the drain.

[0160] The oil thus separated rises below the apex of the drain pipe (12) and is fed via the oil drain pipe (48) arranged in the apex to an oil collector (47) arranged in the concrete shaft (23).

[0161] To prevent the oil separated by the coalescence stage from escaping uncontrollably into the storage tank or trench through a drain pipe slot (13) extending to the apex of the drain pipe (12), the drain pipe (12) is provided with only one row of drain pipe slots (13) on both sides, positioned as deeply as possible. This creates a sealed vault within the drain pipe (12) above the drain pipe slot (13), where the oil can collect and, under its own buoyancy, leave the system via the oil drain pipe (48).

[0162] Figure 6 shows in horizontal section in addition to Figure 2 the coalescence separator elements (40,46) integrated into the drain pipe (12), which lie firmly against one another with their end faces at the element joints (35).

[0163] The longitudinally extending transition areas (45) between the drain pipe (12) and the coalescence separator elements (40, 46) arranged at a distance therefrom are also shown.

[0164] The concrete shaft (23) also shows the oil collector (47), which is sealed off from the rest of the area and to which the oil retained by the coalescers (40) is fed via the oil drain pipe (48).

[0165] To avoid confusion, the drain pipe slitting (13) has not been shown here.

[0166] In Figure 7 Another of the many complementary and combinable treatment processes or components that can be integrated into the sedimentation plant (11) is shown.

[0167] Filter elements (29) filled with filter substrate (27) are shown, which can also be inserted into the drain pipe (12) as individual segments or elements via the rails (30) on both sides. The filter substrates (27), filled into the filter elements (29) as bulk material or inserted as rigid components, can cover a very broad cleaning spectrum depending on the task and, in combination with the sedimentation system (11), even exceed the cleaning performance of natural infiltration basins.

[0168] In the example shown, the filter substrate will gradually permeate the entire filter substrate (27) in the filter element (29), starting horizontally on both sides and ending increasingly vertically. Both the inner element surface (32) and the outer element surface (33) are water-permeable, allowing water to pass from the inside through the filter substrate (27) to the outside and from there to the drain pipe slot (13), after which it enters the storage tank or infiltration trench. To ensure the length of the filter path and to prevent short circuits, both element sides (31) of the filter elements (29) are designed to be watertight.

[0169] Even if the filter elements (29) are advantageously supplied with air from below as far as possible, an increasing decrease in the filtering effect and the associated sealing of the filter elements (29) cannot be avoided over time.

[0170] In order not to impair the function of the sedimentation system (11), the filter elements (20) are equipped with an overflow relief device (34) in the apex of the filter elements (29).

[0171] If the water must be passed through the filter elements (29) for cleaning purposes, the overflow relief (34) can be completely or partially closed with a plug (28).

[0172] The partial closure of the sealing plug (28) can also be adapted to the increasing water pressure via a float- or spring-controlled system, so that an increasing water flow only begins above a predetermined pressure.

[0173] Not in the Figures 1 to 10 Simple filter elements were shown, which consist only of filter fleece and can also be pushed into the drain pipe (12) as a half-shell with a corresponding distance to the drain pipe slit (13) over the rails (30) on both sides.

[0174] Depending on the task, these can also be equipped with an overflow relief device (34), which may be dependent on water pressure, as is the case for all filter elements.

[0175] Also, none of the horizontal sections shows the Figures 2 , 4 , 6 , 8 , 10 It is shown that the treatment processes can alternate or be interrupted over the length of the drain pipe (12) or the sedimentation system (11).

[0176] Thus, it is quite sensible to arrange a sedimentation via lamella packs (43) integrated into the sedimentation system (11) followed by an area with coalescence separators (40, 46) and only through these to allow water access to the drain pipe slot (13).

[0177] In the case of correspondingly long sedimentation sections (11, 12), the individual treatment assemblies (29, 40 + 46, 43) or their individual elements (29, 40 + 46, 43) can be interrupted or connected to one another with liquid-tight half-shells of any length in order to be able to distribute water treatment better and more effectively over the entire length of the sedimentation system (11).

[0178] Especially since it makes no sense to equip long sedimentation sections (11,12) with lamella packs (43) and / or coalescence separators (40,46) and / or fleece or substrate filters (29), since the high water throughput or the good cleaning performance of the individual treatment assemblies (29,40+46,43) does not require the entire length of the sedimentation section (11,12).

[0179] The drain pipe slitting (13) can also vary significantly along the length of the drain pipe (12), which is also not visible in the figures. Since the highest flow velocity occurs at the beginning of the sedimentation section, which usually decreases evenly to zero from there to the end of the sedimentation section, the drain pipe slitting (13) should generally be placed further upwards at the beginning and only extended to the lowest point at the end of the section, which should be only a few millimeters above the maximum settling space. If the drain pipe slitting were already at the lowest level in the inflow area, this would lead to avoidable sediment input into the storage or infiltration trench body.

[0180] As already mentioned in the Figures 4 and 6 was clearly visible in Figure 8 a horizontal section with identical basic structure is shown, which is equipped with filter elements (29) according to Figure 7 inside the drain pipe (12).

[0181] The element joint (35) between the individual filter elements (29) can be seen, as well as the inner (32) and outer (33) water-permeable element surfaces arranged symmetrically on both sides.

[0182] In the middle of the filter element (29) the round overflow relief (34) with the sealing plug (28) is shown.

[0183] To avoid confusion, the drain pipe slit (13) has not been shown here either.

[0184] Figure 9 shows a pre-cleaning system integrated into the concrete shaft (23) and a subsequent multi-stage treatment cascade running across the cross-section of the drain pipe (12).

[0185] Pre-treatment takes place via a coalescence stage (40) and a sedimentation chamber (20). The coalescence stage is separated from the subsequent treatments by a separate pre-chamber (36) with a sealed area at the bottom by a pre-chamber floor (37).

[0186] In addition, a baffle (38) is installed in front of the sedimentation system (11) to retain the coalesced oil, so that only largely oil-free water, which has previously been treated via the coalescer (40) and the settling chamber (20), can reach the sedimentation system (11) by flowing under the lower edge of the baffle (41) via a transition chamber (42).

[0187] The water flowing into the drain pipe (12) of the sedimentation system (11) separates from heavy sediments as far as possible in the permanently dammed settling area (15) of the drain pipe (12).

[0188] At the same time, the rising water is increasingly pushed into the lamella packs (43), where even the smallest sediments can settle on the lamellae (44).

[0189] After passing through the lamella packs (43), further cleaning takes place via filter elements (29) with filled filter substrate (27), which, due to the already performed multi-stage sedimentation (20, 15, 43), do not have to be as thick as in Figure 7 was presented.

[0190] Only then does the now very well pretreated water reach the storage or infiltration body via the drain pipe slit (13) of the drain pipe (12).

[0191] Figure 10 shows the multi-stage treatment method already described in detail above Figure 9 in horizontal section.

[0192] The element and pack joints (35) of the filter elements (29) and plate packs (43) standardized in length dimensions are superimposed here and thus recognizable as only one line.

[0193] To avoid any confusion, the drain pipe slitting (13) has been omitted here. List of reference symbols

[0194] 10Treatment plant 11Sedimentation plant 12Drain pipe 13Drain pipe slitting 14Unslitted area 15Settling area 16Mean settling maximum 17Invert level 18Concrete pipe invert 19Concrete pipe 20Settling chamber 21Shaft invert 22Inspection opening 23Concrete shaft 24Stiffening ribs 25Drain pipe inner wall 26Shaft lining 27Filter substrate 28Closing plug 29Filter element 30Rails 31Element sides 32Inner element surface 33Outer element surface 34Overflow relief 35Element / package joint 36Antechamber 37Antechamber floor 38Baffle 39- / - 40Coalesch 41Baffle bottom edge 42Transition chamber 43Lamella packs 44Lamellar blades 45Transition areas 46Half shell 47Oil collector 48Oil drain pipe

Claims

1. Underground treatment plant (10) for rainwater installed in the ground, which is arranged in a sewer pipe or directly connected to the inlet and / or outlet sewer pipe, comprising a sedimentation plant (11) with a drainage element (12) made of round or square pipes as well as cubic or polygonal components, which is designed with at least one supply line (19) to a shaft (23) with a settling chamber (20), wherein the discharge from the shaft (23) in the upper part or parts of the outer wall of the drainage element (12) is water-permeable and the remaining lower part of the outer wall is watertight, forming a settling area (15), and wherein the settling area (15) is operated in a permanent backwater state, in that the sediments washed into the shaft (23) and settling area (15) remain below the upper water-permeable partial surfaces of the outer wall of the drainage element (12) in the water bath up to this height as water-saturated sludge and, via the drainage pipe slots (13) attached to the upper part of the drainage element (12) is identical to or larger than the full-circle cross-sectional area of the smaller-diameter pipe (19), thereby ensuring a backflow-free inflow from the pipe (19) via the shaft (23) into the sedimentation system (11).

2. Treatment plant (10) according to claim 1, characterized in that the treatment plant (10) is installed in a casing that is completely sealed in the wall and is penetrated by at least one inflow and one outflow pipe.

3. Treatment plant (10) according to claim 1 or 2, characterized in that the treatment plant (10) is part of an underground water storage and / or infiltration system.

4. Treatment plant (10) according to at least one of the preceding claims, characterized in that the outer wall of the drain element (12) or drain elements (12) is made of round or square drain pipes (12), cubic trench construction kits (e.g., Rigo-Fill), half-shells (e.g., Eurofiltrator), and / or other polygonal components (e.g., made of plastic, concrete, or metal).

5. Treatment plant (10) according to at least one of the preceding claims, characterized in that the shaft (23) and / or the drain element (12) or drain elements (12) are equipped with at least one sedimentation plant (11), a filter (29, 43), and / or a light liquid separator (40, 46) in any distribution, arrangement, and sequence.

6. Treatment plant (10) according to at least one of the preceding claims, characterised in that the shaft (23) and / or the drain element (12) or drain elements (12) provide at least two areas, one of which serves to accommodate the sedimentation system (11), a filter (29, 43) and / or light liquid separator (40, 46), and another area is or are to be used for storing (15, 20) the substances separated during treatment.

7. Treatment plant (10) according to at least one of the preceding claims, characterized in that the components designed as modules for the treatment and / or cleaning of the treatment plant (10) can be inserted and mounted in the treatment plant (10) and later dismantled for inspection and overhaul work.

8. Treatment plant (10) according to at least one of the preceding claims, characterized in that at least one conventional sewer pipe is arranged between at least one shaft (23) and at least one drain element (12) and / or at least two drain elements (12).

9. Treatment plant (10) according to at least one of the preceding claims, characterized in that it has at least one overflow relief (34).

10. Treatment plant (10) according to at least one of the preceding claims, characterized in that the inflow and / or outflow of the treatment plant is connected directly to a sewer pipe.

11. Treatment plant (10) according to at least one of the preceding claims, characterized in that a filter fleece or filter substrate (27) is arranged inside and / or below the storage body.

12. Treatment plant (10) according to at least one of the preceding claims, characterized in that the drain element (12) or drain elements (12) is or are to be equipped with at least one lateral inflow.