NL1018703C2 - Sewage treatment device for purifying effluent, contains filter layer comprising porous material filter elements - Google Patents

Abstract

The first filter layer (5) for the effluent to pass through comprises a large number of filter elements (6) made from a porous material. A device for purifying effluent or sewage comprises a first chamber (2) containing at least two filter layers (5, 7), through which effluent added via at least one inlet opening (14) above the device flows under the force of gravity, with the purified water leaving via an outlet opening (15). The first filter layer comprises a large number of filter elements made from a porous material.

Description

Brief description: Waste water treatment plant.

DESCRIPTION

The invention relates to a device for purifying waste water comprising a first space, in which at least a first layer of filter material and at least a second layer of filter material can be accommodated and wherein waste water via at least one inlet opening arranged at the top of the device under the influence of gravity flows through the first layer and the second layer and leaves the device in purified form via at least one outlet opening arranged at the bottom of the device.

Such a device is known, for example, from European Patent Publication No. 0 821 658.

Although in the Netherlands in particular 97% of the houses and 15 companies are connected to the sewerage system, in particular homes in the outlying areas, farms and campsites in connection with the prevailing legal provisions for the unclean discharge of waste water have to rely on another form of waste water discharge.

A facility for treating waste water is the storage of untreated waste water in so-called underground septic tanks. Such septic tanks become full over time and must therefore be regularly emptied.

An application which provides for the purification of waste water on site and the discharge of the purified waste water is described in the European patent publication cited above. The purification device is, for example, set up in-depth in the ground, after which the waste water is introduced into the device via an inlet opening placed at the top of the device. Under the influence of the force of gravity, the waste water flows or seeps through the first filter layer, leaving the unresolved contaminants in the filter layer. The organic impurities dissolved in the waste water are biodegraded, i.e. by bacterial cultures suitable for this, which develop after a short time in the first, but also in the second filter material.

The biodegradation of the contaminants present in the waste water can take place under aerobic or anaerobic conditions. The coarse filtering through the filter material and the fine biological filtering / purification through the bacterial cultures in the filter material results in a stream of purified waste water, which in terms of remaining contamination meets the legal requirements to be discharged directly into the surface and / or groundwater. turn into.

A known application of (biological) water purification is the use of a sand filter, through which the waste water seeps. Disadvantages of sand filters lie in the possibility of silting up the sand filter with contaminants (for example oils and fats) from sludge-containing waste water. On the other hand, a sand filter is characterized by a relatively high flow rate, which promotes less development of the appropriate bacterial cultures. In addition, sand filters settle over time, whereby the functionality decreases and the filtering and / or purifying effect of the sand filter can come to a standstill.

A solution for building up sand filters in layers, wherein in the flow direction of the waste water, given the different sand layers in terms of grain size, are built up from coarse to fine, do not offer adequate measures to prevent the sand filter clogging up. Over time, the entire sand filter must be replaced, which limits the functionality and service life of the filter system and also makes the filter system less suitable for deployment in remote areas.

Another application of a filtering system according to the aforementioned preamble makes use of filtering layers composed of mats of rock wool fibers. Even with the use of rock wool mats 1018703 «3 there is still the risk of clogging up the rock wool material due to sludge-containing waste water, which also limits the functionality and service life of a filtering system or makes it maintenance-unfriendly.

The invention has for its object to provide a biological purification system which is characterized by a relatively long service life, does not have the disadvantages of the filter systems already known and is in particular very maintenance-friendly, which renders the filter system according to the invention very suitable for deployment on those places where a public sewer system has not (yet) been installed.

According to the invention, the device for purifying waste water is characterized for this purpose in that at least the first layer of filter material is composed of a large number of first filter elements made of porous material. Preferably, the filtering elements are made of packed fiber material. The filtering elements can have a regular shape, for example a cube, or an irregular shape.

In another embodiment of the device according to the invention, wherein the device further comprises a second space separated from the first space by means of an intermediate plate, in which at least a third layer of filter material can be accommodated, this is characterized in that the third layer of filter material is composed of a large number of third filter elements made of porous material. These third filter elements can also be made of packed fiber material 25 and have a regular shape, for example a cube, or an irregular shape.

The first and third filtering elements preferably differ from each other in such a way that they have a different shape or different dimensions. In another embodiment, the first and third filter elements have a different fiber density.

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The use of a large number of filter elements made from packed fiber material must be sought in mostly chaotic orientation of the filter elements with respect to each other, whereby on the one hand a good filtering of the coarse impurities from the waste water is possible and on the other hand in the filter elements the appropriate conditions prevail, which allow biodegradation of contaminants. The clogging of such a filter bed will therefore not occur quickly, while at the same time the waste water can leave the device in a sufficiently pure manner.

In a highly functional embodiment of the purification device according to the invention, it is characterized in that a removable compartment can be placed in the first and / or the second space for receiving the filter elements. In a more specific embodiment, the compartment is composed of at least one water-permeable bag. Because the filtering elements are accommodated in the first and / or third space in a compartment which can be removed from the device, this filtering device is very suitable for on-site maintenance, preferably performed by the user or owner of the purification device.

By taking the compartment or the water and air permeable bags out of the device, the mutual orientation of the filter elements can be changed by shaking, so that, for example, an approaching and imminent silting up of the filter layer composed of filter elements 25 is broken. By refitting the compartment or the bag with the reoriented filter elements, the purification device can be put into use again, because filtering and purification is again made possible by the reorientation.

Optionally, the user or owner of the purification device can clean the relevant compartment or the bag itself with the aid of water, so that the filter elements in a cleaned form are again suitable for use as filter material. It will be clear that as a result the service life of the filter-annex purification device is considerably extended (up to twice the usual service life up to now) and any maintenance or replacement of the filter material can be omitted and the use of suitable maintenance personnel cannot be avoided. longer necessary.

In another embodiment of the device, it is characterized in that the second layer of filter material is composed of a flat plate of porous material, for example packed fibers. To this end, in the specific embodiment according to the invention, the density of the porous material can change in the flow direction of the waste water and increase when viewed in a specific direction in the flow direction of the waste water.

More specifically, the flat plate of porous material 15 is composed of a part layer with a low density and a part layer with a high density.

The use of such a second layer of filter material provides an additional filtering and purifying effect. While the filter elements in the first layer protect this second layer of filter material from clogging up by removing the undissolved contaminants from the waste water by the first filter elements, the low-density sublayer of the second filter layer offers the possibility of small contaminants spread over the first sublayer, so that here too clogging and blocking of the second filtering layer is prevented. In the sub-layer with a low density and the sub-layer with a high density, the suitable bacterial cultures can thus develop for the biological degradation of the small impurities present in the waste water.

In order to promote a particularly aerobic degradation of waste materials from the waste water, the device according to the invention is characterized in that at least one inlet opening for air is arranged just below the first space in the device.

The invention will now be explained in more detail with reference to a drawing, which drawing shows:

Figure 1 shows an embodiment of a device for purifying waste water according to the invention.

The embodiment shown in Figure 1 for a device for purifying waste water is formed by a housing 1 which can be accommodated completely immersed in the soil. In this embodiment the embodiment has a first space 2 and a second space 3 which are separated from each other by means of an intermediate plate 4.

In the first space 2, a first filtering layer 5 and a second filtering layer 7 are included on top of each other and viewed in the direction of flow of the waste water. According to the invention, the first filtering layer 5 is made up of a large number of filtering elements 6, 15 which are made of a porous material, for example packed fiber material. As the figure shows, the many filter elements 6 have an irregular shape. On the other hand, the filter elements can be made in the form of a cube.

Below the first filtering layer 5 a second filtering layer 7 is included, which is preferably composed of a mat made of porous material, for example rock wool fibers. More specifically, the layer 7 has a density which, viewed from the top down, seen in the direction of flow of the waste water, changes, and more particularly increases. In a very specific embodiment which is also shown in Figure 1, the second filtering layer 7 consists of a first part layer 8 of compressed rock wool fibers which has a low density, as well as a second part layer 9 also made from packed rock wool fibers, but now with a higher density. The function of this second filtering layer 7, which changes in density 30, will be explained later in the description.

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As Figure 1 also shows, just below the first space 2 and more particularly just below the intermediate plate 4 which separates the first space 2 from the second space 3, an inlet opening 16 is provided for introducing air. This air will also be absorbed by the water that leaves the first space through the intermediate plate 4. The air and in particular oxygen uptake in the water promotes an aerobic biodegradation of contamination in the second space and preferably in the third layer 10. In order to promote the uptake of air in the waste water, just below the intermediate plate 4 is at the level of a large number of elements 17 made of plastic are arranged in the inlet opening 16.

Although a device for purifying waste water according to the invention can function very well if it comprises only one space 2 with the first filter layer 5 and the second filter layer 7 included therein, the device according to the invention has a second space 3 in this embodiment which is separated from the first space 2 by means of an intermediate layer 4.

According to the invention, a third filtering layer 10 is also included in the second space 3, which according to the invention 20 is composed, like the first filtering layer 5, of a third filtering element 11 made of a large porous material, for example packed fiber material. The third filtering elements 11 can have a smaller the shape of the first filtering elements 6 from the first filtering layer 5 and the shape is also regular, being a cube. Optionally, the density of the third filter elements 11 may differ from the density of the first filter elements 6. Optionally, the density of the third filter elements 11 is higher than the density of the first filter elements 5.

Optionally, an additional fourth layer of filter material 12 is included in the space 3 in another embodiment, which also consists of a large number of in this case fourth filter elements 13. These porous filter elements 13 have an even smaller The third filtering elements 11 and first filtering elements 6, respectively, are also preferably made of packed fiber material.

For purifying waste water, one or more inlet openings 14 are provided at the top of the device 1, through which waste water can be introduced into the device 1. Under the influence of gravity, this waste water seeps through the first filtering layer 5, the second filtering layer 7, the intermediate plate 4, and then through the third filtering layer 10, 10 optionally through the fourth filtering layer 12 and then leaves the more or less purified form. device via one or more outlet openings 15.

The many filter elements 6 which form the first filter layer 5 serve to extract coarse impurities from the waste water that is introduced into the purification device via the inlet opening (s) 14. Waste water seeps through the many gaps between the different filter elements 6. Because the filter elements 6 are made of packed fiber material and thereby have a porous composition, these filter elements 6 also absorb water, so that they are completely saturated with waste water over time. Due to the relatively large gaps between the filter elements 6, air can also penetrate the first filter layer 5, which provides a suitable circumstance for creating aerobic bacterial cultures for biological purification of the waste water that is absorbed in the various filter elements 6. Due to the relatively large gaps between the different filtering elements 6, the chance of the first filtering layer 5 clogging up due to the coarse impurities from the often sludge-containing waste water is small, because after all there are always other openings between the different filtering elements 6, as a result of which the waste water under influence can seep away from gravity downwards.

The chaotic orientation of the filter elements 6 in the layer 5 layer (and the filter elements 11 in the layer 10) results in a different fiber orientation of the different filter elements relative to the flow direction of the waste water. This means that certain filter elements determined by this fiber orientation absorb water, so that in such filter elements a biological degradation of impurities occurs, while in filter elements with a different fiber orientation waste water seeps through the element, resulting in a filtering of the water.

The waste water that has already been purified in the first filtering layer 5 from the small, undissolved impurities can then seep through the second filtering layer 7, which according to the invention is preferably composed of a first and second sublayer 8 and 9 respectively, which sublayers are each composed however, from packed fibers of different densities. According to the invention, the first sublayer 8 has a low more open density, while the second sublayer 9 has a higher density, i.e. a more compact shape. Due to the lower density of the first sublayer 8, any small impurities still present in the waste water can be encapsulated in the first sublayer 8 over a relatively large surface and depth, without this now immediately leading to a clogging of the second filter layer 7. .

Although this clogging up of the second filter layer 7 is already avoided by the composition of the first filter layer 5, it is always possible that due to the relatively large gaps between the different first filter elements 6, contaminants in the waste water can reach the second filter layer 7.

In a first embodiment of the purification device according to the invention, the waste water that has been purified by the first filtering layer 5 and the second filtering layer 7 can have such a quality that this waste water can be discharged directly onto the surface water and / or groundwater. However, with more contaminated waste water 1018708 · 10 and also in order to obtain waste water with a higher pure content, the device according to the invention has a second space 3, in which a third filter layer 10 and optionally a fourth filter layer 12 is included.

Analogously to the composition of the first filtering layer 5, the third filtering layer 10 (and optionally the fourth filtering layer 12) has a large number of filtering elements 11 (13 respectively) which is also made of packed fiber material. A further biodegradation of the contaminants present in the waste water 10 occurs in this third filter layer 10, and often under anaerobic conditions.

The purified waste water can leave the installation via one or more outlet openings 15 and meets the legal requirements with regard to pollution in order to be able to be discharged directly into the surface and / or ground water.

This makes the purification device according to the invention very suitable for use in places where a public sewer system is not yet present, for example in homes in the outer areas, on farms and camping sites. The device according to the invention is therefore very well suited for use in 20 countries, wherein the sewerage system is not yet developed that far. With such a treatment plant, the (European) legal requirements can still be met with regard to the discharge of waste water.

In order to considerably extend the service life of the purification device according to the invention, and in particular to simplify the maintenance of the device, the first filtering elements 6, which form the first filtering layer 5, are, according to the invention, accommodated in a compartment 18 which is simply removed from the device 1 is removable. Thus, the user or owner of the purification device can remove the first filtering layer 5 on site and possibly clean it so that the filtering layer 5 is again suitable for the first coarse purification of the waste water. This cleaning of the first filtering layer may in particular be necessary in the case of an impending clogging which, despite the large gaps between the different filtering elements 6, can still occur after some time. Although the user or owner does not have to spray the first filtering layer 5 specifically with the aid of a high-pressure hose 5, a simple shaking of the filtering elements 6 placed in the compartment 18 can also result in a new reorientation of the filtering elements 6, whereby the reorientation or shaking off the filter elements 6 again open gaps between the filter elements 6 arise for the transport of waste water and the extraction of coarse impurities therefrom. This shaking or reorientation of the filter elements 6 also causes a displacement of the first coarse impurities through the entire first filter layer 5 and not specifically at the top of the first filter layer 5. This also prevents a too fast silting of the filter layer 5 and the service life of the filter layer 5. device considerably extended.

In another embodiment of the purification device according to the invention, the first space 1 does not have compartment 18, but the first filtering elements 6 are accommodated in one or more water and air permeable bags 19, which can be manufactured, for example, from fabric or mesh material. The bags or the net 19 with filtering elements 6 can be easily removed from the device by the user and the orientation of the filtering elements 6 can be changed by brushing or shaking. The use of a bag also makes cleaning a lot easier.

It will be clear that a compartment 18 may also be accommodated in the second space 3. It will also be clear that the third filtering layer 10 or the fourth filtering layer 12 can also be accommodated in at least one bag 19 as shown in the second space 2, so that also the filtering elements 11 and 13 can be removed from the device for cleaning. On the other hand, it must be noted that, due to the specific construction of the purification device according to the invention, such a good purification of the waste water and in particular a very good purification of the coarse contaminants from the waste water is already present in the first space. it is obtained that the third and optional fourth filtering layer 12 are permanently incorporated into the device 1.

By using filtering elements 6 in the first filtering layer 5, which filtering elements 6 are preferably removable with the aid of the compartment 18 or the bags 19, a very good purification of the waste water with regard to the coarse impurities is already obtained. The risk of clogging or clogging of the third filter layer 10 and the optional fourth filter layer 12 by the coarse impurities is hereby prevented. The purification of the waste water in the second space 3 is then almost completely of a biological and aerobic nature.

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Claims (18)

1. Device for purifying waste water comprising a first space, in which at least a first layer of filter material and at least a second layer of filter material can be accommodated and wherein waste water via at least one inlet opening arranged at the top of the device under the influence of gravity through the first layer and the second layer flows and leaves the device in purified form via at least one outlet opening arranged at the bottom of the device, characterized in that at least the first layer of filter material is made up of a large number of first filter elements made of porous material. Device according to claim 1, characterized in that the first filtering elements are made from packed fiber material. Device according to claim 1 or 2, characterized in that the first filtering elements have a regular shape, for example a cube. 4. Device as claimed in one or more of the foregoing claims, characterized in that the first filtering elements have an irregular shape. 4 * 5. Device as claimed in one or more of the foregoing claims, wherein the device furthermore comprises a second space separated from the first space by means of an intermediate plate, in which at least a third layer of filter material can be accommodated, characterized in that the third layer filter material is composed of a large number of third filter elements made of porous material. Device according to claim 5, characterized in that the third filtering elements are made from packed fiber material. 7. Device as claimed in claim 5 or 6, characterized in that the third filtering elements have a regular shape, for example a cube. 1018709 «4" Device according to claim 5 or 6, characterized in that the third filtering elements have an irregular shape. Device according to one or more of claims 5 to 8, characterized in that the first and the third filter elements have a different shape. Device according to one or more of claims 5 to 9, characterized in that the first and the third filter elements have different dimensions. Device according to one or more of claims 5 to 10, characterized in that the first and third filter elements have different fiber densities. 12. Device as claimed in one or more of the foregoing claims, characterized in that a removable compartment can be placed in the first and / or the second space for receiving the filtering elements. Device according to claim 12, characterized in that the compartment is composed of at least one as a water and air permeable bag. 14. Device as claimed in one or more of the foregoing claims, characterized in that the second layer of filter material is composed of a flat plate of porous material, for example of packed fibers. 15. Device as claimed in claim 14, characterized in that the density of the porous material changes seen in the direction of flow of the waste water. Device according to claim 15, characterized in that the density of the porous material increases in the direction of flow of the waste water. 17. Device as claimed in claim 16, characterized in that the flat plate of porous material is composed of a part layer with a low density and a part layer with a high density. 1018701 · I " Device according to one or more of the preceding claims, characterized in that at least one inlet opening for air is provided in the device just below the first space. 5 1018703 «