LU101579B1 - Filter and device for removing contamination from a liquid, in particular for removing micro- and nano-scale plastic particles from water, method for producing such a filter and its use - Google Patents

Abstract

The invention relates to a filter (1; Ib; Ic) and a device (12; 12c) for removing dirt (6; 6a) from a liquid, in particular for removing micro- and nano-scale plastic particles from water. The at least one filter material (3; 3a; 3c) is expediently covered at least partially with a layer (5; 9; 39) which absorbs the contaminants (6; 6a). Liquid cleaning is advantageously possible without removing mineral substances present as ions. Only dirt that is harmful to a living being is removed. If water is cleaned with a filter according to the invention, its taste, which is determined by the ions and minerals, is advantageously not changed.

Description

FANM-PATENT OS mg Description: Klar20 GmbH, Bruchsal (Germany) "Filter and device for removing contamination from a liquid, in particular for removing micro- and nanoscale plastic particles from water, s method for producing such a filter and its use" The The invention relates to a filter for removing micro- and nano-scale plastic particles from water, which has at least one filter material through which water can flow. The invention also relates to a method for producing a filter for removing plastic particles from water, a device for removing plastic particles from water and a use of a filter. WO 2013/088260 A1 describes a multi-stage water filter that has a filter bed with an ion exchange resin and activated carbon as well comprises a nonwoven filter element. It is also known that the fleece can have a hydrophobic binder. The filter materials known from WO 2013/088260 A1 are not covered with a hydrophobic layer. From US 2010/0200489 A1 a water purification device is known in which a Druckstempe! a pressurized water purification can take place, in which the water to be purified is pressed through a multi-stage filter. The filter comprises eight filter stages, none of which has a filter material which is equipped with a hydrophobic layer for adsorption of plastic particles. It is only known that a filter stage 37 can be impregnated with silver ions.

No. 4,997,576 describes a method for the oxidation of oil films on seawater, in which a surface of glass spheres is hydrophobized and then at least partially coated with TiQ. A sinking depth into the oil film can be set through a degree of hydrophobization and a glass ball weight. However, it is not known to remove plastic particles from drinking water by adsorption.

A method is known from WO 2019/168508 A1 with which organic constituents that arise as a by-product of a chemical synthesis, for example of active pharmaceutical ingredients, can be removed from a liquid. Page 1 is also known

Allocation of glass spheres with a hydrophobic layer. However, there are no indications that the smallest LU101579 plastic particles can be filtered out of water. WO 20199/168811 A1 describes enzymes and bacteria for decomposing PET, s in particular Ideonella sakaiensis 201-F6. Furthermore, water filters for drinking water treatment are known from the prior art, which in particular remove lime or ions from tap water. In addition, activated charcoal filters for cleaning bacterially contaminated water are known.

The disadvantage is that known filters are not designed to remove micro- and nano-scale plastics. Such plastics, which have a particle size between 10 nm and 10 μm and in particular comprise polyethylene (PE), polypropylene (PP) or polyethylene terephthalate (PET), can be absorbed by living beings through drinking water and, due to their small size, have a hormone-like effect in their bodies. This can, for example, worsen the fertility of a person. Furthermore, metabolic diseases can be caused. The present invention is based on the object of developing a filter of the type mentioned at the beginning, by means of which micro- and nano-scale plastic particles can be removed from a liquid. According to the invention, the object is achieved in that the at least one filter material is at least partially covered with a hydrophobic layer which adsorbs the plastic particles. The dirt in the liquid, which is preferably hydrophobic, can be absorbed by the layer of the filter material and thereby removed. A recording is, for example, adherence to the filter material due to the interaction forces of the layer with the contamination. Liquid purification is advantageously possible without removing mineral substances present as ions. Only dirt that is harmful to a living being is removed. If water is cleaned with a filter according to the invention, its taste, which is determined by the ions and minerals, is advantageously not changed.

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The at least one filter material is expediently designed as a membrane or fabric LU101579 and / or comprises particles, preferably spherical particles. A fabric can either be covered with the dirt-absorbing layer after its production or individual threads can be coated before they are woven.

Coated particles, in particular spherical particles, can be arranged in various ways, for example in a cubic closest packing of spheres or a hexagonal closest packing, so that the size of a space formed between adjacent particles through which the liquid flows can be adjusted. A filter material can advantageously be adjusted to the size of the contamination to be removed.

The particles have a diameter between 100 μm and 2 mm, preferably between 500 μm and 1 mm, particularly preferably between 200 μm and 600 μm. A zeolite-like design of the filter material is also conceivable. It is also conceivable that the particles are hollow and in particular are designed as hollow spheres.

In one embodiment of the invention, the layer is hydrophobic and intended to adsorb the contaminants. A hydrophobic layer ensures that no ions are removed from the liquid or that layer components are dissolved out during water treatment. The soiling is adsorbed due to inter- and intramolecular interactions, for example Van der Waals forces. Advantageously, in spite of the small size of the soiling, no close-meshed filter materials are required, which enables high cleaning performance with low pressure, which can even be applied manually.

In a further embodiment of the invention, the dirt-absorbing layer is formed in multiple layers and preferably comprises at least one primer layer set 2a as well as a hydrophobic functional layer provided for adsorbing the preferably hydrophobic dirt. The primer layer can be an adhesion promoter layer which brings about particularly good adhesion of the functional layer to at least one base body of the filter material. The primer layer can be applied, for example, by a dipping process or a sol-gel process and preferably has a homogeneous thickness between 200 nm and 50 μm. It is conceivable that the primer layer is designed as a stabilization layer. A base body of the filter material that is not mechanically loadable can advantageously be stabilized.

1 Furthermore, it is conceivable that several primer layers are provided, of which a first is designed as a stabilization layer and another as an adhesion promoter layer for a functional layer. In one embodiment of the invention, the dirt-absorbing layer is hydrophobic and has hydrocarbon chains with end groups that are designed to form a connection with an activated surface of the filter material and / or an activated surface of a primer layer of a multilayered layer, preferably trichlorosilanes, particularly preferred Octadecyltrichlorosilane. Trichlorosilanes, especially octadecyltrichlorosilane (OTS), are particularly suitable for forming a hydrophobic layer on which plastic particles can be adsorbed. A hydrocarbon chain preferably has between 4 and 25 carbon atoms, in particular between 6 and 15, preferably between 8 and 12. It is conceivable that the contaminant-absorbing layer has alkanes, alkenes, alkynes or esters with terminal trichlorosilanes. In a further embodiment of the invention, at least one primer layer of a multi-layer layer receiving the particles is formed from silicon dioxide or has silicon dioxide. Silicon dioxide (SiO2) is suitable because this material can be activated particularly well, that is, by surface treatment with acid, in particular piranha solution, it can form a particularly stable bond with a material from which the functional layer is formed. A silicon dioxide surface can be activated, for example, by a mixture of hydrogen peroxide and sulfuric acid, whereby silanol groups or hydroxide groups are formed, which are intended for connection with the material forming the 3 functional layers, which is preferably octadecyltrichlorositane (OTS).

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Further, one formed from SiO: or SiO; having layer particularly stable and suitable for ATS sealing of at least one base body of the filter material. In one embodiment of the invention, the filter material has at least one base body s, on which a primer layer of a multi-layer layer that absorbs the dirt is applied to form the filter material. The primer layer can also be provided for sealing the at least one base body. Direct contact of the liquid, from which contamination is to be removed, with the base body is advantageously prevented.

Furthermore, base bodies made of materials can advantageously be used which are not suitable for removing dirt without a sealing primer layer, for example wood, natural fibers such as hemp, which cannot be activated, i.e. cannot form silanol or hydroxide groups. If the at least one primer layer is formed from silicon dioxide or has silicon dioxide, activation is possible.

It is conceivable that the base body is formed from a ceramic material, for example an oxide ceramic such as aluminum oxide (Al2Os) or zirconium oxide (ZrO2), and / or a non-oxide ceramic such as tungsten carbide (WC) or silicon carbide (SiC).

Furthermore, it is conceivable that the base body is formed from a metal, for example steel or a light metal or a light metal alloy, in particular aluminum and / or magnesium.

It is also conceivable that the at least one base body is formed from zinc hydroxide,% magnesium hydroxide, aluminum hydroxide, iron hydroxide (iron-ill hydroxide), goethite, boehmite, silver hydroxide and / or from a rock, for example a mineral stone such as tourmaline or amethyst.

The at least one base body is expediently formed from a renewable raw material, in particular wood, a recycled material, in particular glass, and / or silicon dioxide, or comprises one of these materials. Such materials are readily available, disposable and recyclable.

In a further embodiment of the invention, the contaminant-absorbing layer or a functional layer of a multi-layered layer absorbing the contaminants has at least one microorganism, preferably bacteria, in particular Ser 4/10

Ideonella Sakaiensis, which is intended to decompose the pollution. Decomposition can occur through metabolism. Ideonella Sakaiensis is a bacterium that can break down polyethylene terephthalate (PET) and is harmless to mammals and humans. This requires an enzyme, PETase, which can be added to the liquid in the area s of the filter material.

The microorganism can colonize the filter material. It is conceivable that a surface of at least one base body of the filter material, which is formed in particular from silicon dioxide, is roughened in order to achieve better adhesion of the microorganism.

It is conceivable that the layer or the functional layer of a multilayer layer has both a microorganism and hydrophobic areas. In one embodiment of the device according to the invention for removing contamination from a liquid, a means for applying pressure to a receiving space for the liquid is provided. A volume flow through the filter can advantageously be improved. For pressurization, a mechanically or manually operable pump can be provided, which pressurizes a receiving space for the liquid to be cleaned, so that the liquid flows through a filter into a removal space. A filter device is created for domestic use, for example for the treatment of drinking water for the preparation of baby food. In a further embodiment of the device according to the invention, further filters are provided through which the liquid can flow when flowing out of the receiving space into the removal space. Each filter can be designed to remove a certain amount of contamination from the liquid. The filters can be part of a filter cascade and be fluidically connected to one another. A device is advantageously created which can be used flexibly by using filters which remove certain contaminants, for example nitrite or heavy metals such as lead.

a0 It is conceivable that lime or similar substances that affect the taste of water, for example, are removed. Each filter is expediently exchangeable. The device is advantageously modularly expandable. In addition, only those filters of the device have to be replaced which no longer guarantee adequate filtering.

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Adjacent filters can be detachably connected to one another by a plug, clamp and / or screw connection. The invention is explained in more detail below with reference to exemplary embodiments and the accompanying drawings relating to the exemplary embodiments. 1 shows an embodiment of a filter according to the invention with details, FIG. 2 shows details of a further embodiment of a filter according to the invention, FIG. 3 shows several embodiments of filter devices according to the invention, FIG. 4 shows a particular embodiment of a filter device according to the invention. A filter (1) shown schematically in longitudinal section in FIG. La comprises a filter housing (2) into which a filter material (3) is introduced. The filter material (3) has a plurality of silicon dioxide (SiO;) formed, 1 mm large glass spheres (4) shown in cross section in Fig. 1b, which are arranged in a cubic, densely packed sphere in the filter housing (2) and with a hydrophobic layer (5) containing octadecyltrichlorosilane (OTS), which completely covers one surface of each glass sphere (4).

Water contaminated with micro- and nano-scale plastic particles (6) can flow into the filter housing (2) in the direction of an arrow (7) and flow out of the filter housing (2) in the direction of an arrow (8).

Because the layer (5) is hydrophobic, the hydrophobic micro- or nanoscale plastic particles (6) to be removed are attracted, for example by van der Waals forces, and adhere to the layer (5).

Although not shown in FIG. 1, it is conceivable that the filter (1) has a filter material (3) which is formed from a glass fiber fabric, the individual fibers of which are each covered with a layer (5). Several layers of fabric can be arranged one behind the other in a flow direction (7, a 8) of the filter (1). Meshes are preferably offset from one another.

Reference is now made to FIG. 2, where parts that are the same or function in the same way are denoted by the same reference number as in FIG. 1 and the letter a is added to the relevant reference number. Page SOON

A filter material (3a} shown schematically in cross section in Fig. 2a comprises several spheres (4a) formed from 0157 aluminum oxide (AO), the surface of which is covered with a multi-layer layer (9). The layer (9) comprises two layers (10, 11), of which a primer layer (10) is formed from SiO; and a hydrophobic functional layer (11) is formed from octadecyltrichlorosilane (OTS). A filter material (3a) shown schematically in a cross section in FIG. 2b comprises a wood splinter (4a), the surface of which is covered with a multi-layer layer (9). The layer (9) comprises two layers (10, 11}, of which a primer layer (10) is formed from SiO: and a hydrophobic functional layer (11) is formed from octadeclytrichlorosilane (OTS) Reference is now made to FIG. 3, where the same or equivalent parts are denoted by the same reference number as in FIGS. 1 and 2 and the letter b is added to the relevant reference number.

A filter device (12), shown schematically in an isometric view in Fig. 3a, comprises two water containers (13, 14) connected to one another by a releasable and gas-tight plug connection, of which a first (13) is for receiving water from which micro- and / or nanoscale plastic particles are to be removed, and a second (14) is provided as a removal container. Water can be filled into the first water container (13) through an upper opening (15) which can be closed with a pivotable flap (16). Through a lower opening (17), water to be cleaned can be fed into the lower water tank (18) through a vacuum that can be generated by a hand pump (18), through an exchangeable filter (1b) and a handle (19) of the hand pump (18) 14) and can be removed through a pivotable outlet channel (20). In the position shown in FIG. 3a, the outlet channel (20) is in a basic position in which no water can be removed.

sc The second water container (14) is also designed in two parts, a first part (21) being provided as a removal space for purified water and a second part (22) as an intermediate storage space in which the water after flowing through the filter (1b} and before flowing through the A first connection channel (23) connects the handle (19) fluidically to the first part (21) of the second water container (14) and a second 3 connection channel (24) to its second part (22).

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The second part (22) is detachably connected to the first part (21). This allows the 01978 replaceable filter (1b) to be removed from the device (12) and replaced by another. A fluid-tight screw connection (25) is provided for its attachment. The negative pressure can be generated by operating the hand pump (178) by moving a knob (26) of the hand pump (18) up and down. Although not shown in FIG are connected to one another in a cascade-like manner, so that the water to be purified flows through each one. Each of the filters of the cascade is exchangeable. Another embodiment of a filter device (12) according to the invention, shown schematically in a side view in FIG. 3b, differs from that shown in FIG that a single cylindrical container (27) is provided into which a filter plunger (28) is immersed, at the lower end of which a filter (1h) is attached. The filter (1b) is detachably connected to a rod (29) on which a handle (30) is fastened on a side facing away from the filter (1b), the handle (30) and the rod (29) form a hand pump (18).

The filter (1b) divides an interior space of the container (27) into two areas (31, 32) which are fluidically connected to one another by the filter (1b;) one of which is delimited by a base (33) of the container (27) The first area (31) is provided for receiving water to be cleaned and contaminated with micro- and / or nanoscale plastic particles, while an area (32) 2 delimited by an upper side (34) of the filter (1b) is designed for receiving purified water . To clean the water, the first area (31) is filled with dirty water. Then the filter (1b) is inserted into the container (27). By pressing the handle (30) in the direction of the base (33), the first area ( 31) is reduced, water flows through the filter (1b) into the second area (32), which becomes larger. Dirt remains in the filter (1b), purified water can be taken from the area (32) 3c schematically in A filter device (12) according to the invention shown in a side view differs from that shown in FIG. 3b a in that a filter cascade is provided, with a first filter (1b) on the side 8/10

Removal of plastic particles is provided and a second filter (35) for removing lime. Both filters (1b, 35) can be replaced individually. Reference is now made to FIG. 4, where the same or equivalent parts are denoted by the same reference number as in FIGS. 1 to 3 and the respective reference number is accompanied by the letter c.

A filter device (12c) shown schematically in a side view in FIG. 4 differs from that shown in FIGS. 1 to 3 in that the filter device (12c) has a cylindrical filter space (36) into which the water to be cleaned is fed through a The inlet (37) flows in and, after it has been cleaned, can be removed through an outlet (38). A cylindrical filter (1c), which has a water-permeable membrane (3c) coated with bacteria of the Ideonella Sakaiensis type (39), is attached in the filter space. The bacteria are intended to absorb micro- and nano-scale plastic particles, inshesodere made of polyethylene terephthalate (PET), from water that is too clean and metabolize them.

A radial flow is generated by a stirring disk (40) attached below the filter, as a result of which water to be cleaned can flow into and out of the cylindrical filter (1c) through a jacket surface.

PET particles are absorbed and metabolized by the bacteria. A cylindrical filter housing (2c) and the filter space (36) are arranged coaxially.

= The operation of such a fishing device (12c) takes place discontinuously or continuously. A discontinuous operation can be provided, for example, for a stationary sewage treatment plant, while continuous operation is advantageous in the case of a table-top device.

It goes without saying that all combinations of features of the embodiments shown in FIGS. 1 to 4 are conceivable.

In a method for producing a filter material for a filter according to the invention, fused silica beads with a diameter between 1 and 2 mm are placed in what is known as piranha solution (peroxomonosulfuric acid) for 30 minutes Rinsed with deionized water and blown dry with pressurized nitrogen

In the process step, hydroxyl groups are formed on the surface of the silica glass beads, which cause particularly good adhesion of a hydrophobic layer. The surface is activated by this process step. It is conceivable that the silica glass beads are placed in the so-called piranha solution for between 30 and 60 minutes, in particular 45 s or 60 minutes.

In a subsequent process step, 0.2 ml of octadecyltrichlorosilane (OTS) are added to 100 ml of toluene. followed by the addition of the dried silica glass spheres, which are placed in the toluene provided with OTS for 20 minutes. By activating the surface beforehand, one surface of each glass ball is at least partially covered with OTS. It is conceivable that a mixture of toluene and octadecyltrichtorsilane (OTS) contains up to 25% by volume of octadecyltrichlorosilane, in particular 10% by volume, preferably 20% by volume.

The silica glass spheres are then removed, rinsed with toluene and dried in a stream of nitrogen. The balls are then dried in an oven at 120 ° C. for 30 minutes. Better layer adhesion is advantageously achieved.

In a final process step, the silica glass beads are placed in an ultrasonic toluene bath for 5 minutes and, after drying, can be used as filter material for a filter.

To clean the fitter or the filter material, that is to say to remove plastic particles adsorbed on the surface of the filter material, organic liquids are used which bind the plastic particles more strongly than the filter material. For example, a filter can be cleaned by rinsing with pure methanol, followed by rinsing with acetonitrile and a final rinsing with tetrahydrofuran. A different sequence of the three rinsing processes and the use of a mixture of these three substances is conceivable.

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Claims (16)

Claims: LU101579 1. Filter (1; 1b; 1c) for removing micro- and nanoscale plastic particles (6; 6a) from water, which has at least one filter material (3; 3a; 3c) through which the water can flow, characterized in that the at least one filter material (3; 3a; 3c) is at least partially covered with a hydrophobic layer (5; 9; 39) which adsorbs the plastic particles (6; 6a). 2. Filter according to claim 1, characterized in that the at least one filter material (3; 3a; 3c} is designed as a membrane or fabric and / or comprises particles (4; 4a), preferably spherical particles, 3. Filter according to claim 1 or 2, characterized in that the layer (9) receiving the plastic particles (6; 6a) is multilayered and preferably at least one primer layer (10) and one for adsorbing the plastic particles (6; 6a) comprises the hydrophobic functional layer (11) provided. 4. Filter according to one of claims 1 to 3, characterized in that the plastic particles (6; 6a) receiving layer (5; 9) is hydrophobic and has hydrocarbon chains with end groups which are set up to form a compound with an activated surface of the Filter material (3; 3a; 3c) and / or an activated surface of a primer layer (10) of a multilayered layer (9), preferably trichlorosilanes, particularly preferably octadecyltrichlorosilane. 5. Filter according to one of claims 1 to 4, characterized in that at least one primer layer (10) of a multilayer layer (9) receiving the plastic particles (6; 6a) is formed from silicon dioxide or has silicon dioxide. Page 1/3 6. Filter according to one of claims 1 to 5, LU101579, characterized in that the filter material (3; 3a; 3c) has at least one base body (4; 4a) on which at least one primer layer (10) one of the plastic particles (6; 6a ) receiving multi-layer layer (9) is applied to form the filter material. 7. Filter according to claim 6, characterized in that the at least one base body (4a) is formed from a renewable raw material, in particular wood (4a), a recycled material, in particular glass, and / or silicon dioxide (4) or comprises one of these materials . 8. Filter according to one of claims 1 to 7, characterized in that the plastic particles (6; 6a) receiving layer (5; 9; 39) or a functional layer (11) of a multi-layer layer (9) receiving the plastic particles at least has a microorganism, preferably bacteria, in particular Ideonella Sakaiensis, which is provided to decompose the plastic particles (6; 6a). 9, a method for producing a filter (1; 1b; 1c) for removing micro- and nanoscale plastic particles (6, 6a) from water, which has at least one filter material (3, 3; 3c) through which the water can flow , characterized in that the filter material (3, 3a; 3c) is at least partially covered with a hydrophobic layer (5; 9, 39) which adsorbs the plastic particles. 10. The method according to claim 9, characterized in that in order to form the filter material (3; 3a; 3c) a multi-layer layer (9) is applied to at least one base body (4a), with one on the at least one base body (4a) Primer layer (10) and a functional layer {11) for receiving the plastic particles (6; 6a) is applied to the primer layer (10). 11. The method according to claim 9 or 10, Sene 2/3, characterized in that a surface of the filter material (3; 3a; 3c) or the primer layer (10) before application of the layer (5; 9; 39) or a functional layer ( 11) is treated, preferably activated, to improve the adhesion of the layer (5) or the functional layer (11). 12. Device (12; 12c) for removing micro- and nanoscale plastic particles from water, which has at least one filter (1; 1b; 1c) according to one of claims 1 to 8, characterized in that a means (18) for applying pressure a receiving space (13; 31) is provided for the liquid. 13. The device according to claim 12, characterized in that the pressure application means is provided to apply pressure to the receiving space (13; 31) by preferably manual actuation in such a way that the liquid from the receiving space (13; 31) flows through a filter (1; 1b; 1c) flows through into a removal space (21; 32). 14. Device according to claim 12 or 13, characterized in that further filters (35) are provided through which the liquid can flow when flowing out of the receiving space (13; 31) into the removal space (21; 32). 15. Device according to one of claims 12 to 14, characterized in that each filter (1; 1b, 35; 1c) is interchangeable. 16. Use of a filter (1; 1b; € 1) according to one of claims 1 to 8 or a device (12; 12c) according to one of claims 12 to 15 for removing micro- and nanoscale plastic particles (6, 6a) of water. Seve 313