Use of an adsorbent and an adsorbent dosing unit for this use - Patents.com

Abstract

The present invention relates to the use of an adsorbent in a facility for treating liquids to remove dissolved organic and / or inorganic substances. The present invention also relates to a dosing unit for the adsorbent for this use. In order to achieve an improved method for removing dissolved organic and / or inorganic substances in liquids using an adsorbent, in the present invention a water-soluble dosing unit containing an adsorbent is metered into said liquid to be treated to remove dissolved organic and / or inorganic substances depending on the amount of dissolved organic and / or inorganic substances to be removed, and the adsorbent is released. When metered into the liquid to be treated, the dosing unit disintegrates or disperses and releases the adsorbent, which, due to its extremely large surface area, is able to bind large amounts of dissolved organic / inorganic substances.

Description

[Technical field]

[0001] The present invention relates to the use of an adsorbent in a facility for treating liquids in order to remove dissolved organic and / or inorganic substances. The invention also relates to a dosing unit for the adsorbent for this use.

[0002] The invention particularly relates to the use of the adsorbents in plants for treating liquids (municipal or industrial wastewater, drinking water, groundwater, lake / sea and river water, storm water, mixed water and surface runoff) for the purpose of removing dissolved organic matter such as dissolved organic carbon (DOC) or trace substances or impurities (e.g. pharmaceuticals, industrial and household chemicals) and / or inorganic substances such as phosphates, ammonium compounds or metals. [Background technology]

[0003] US Patent No. 5,399,633 describes a method for removing dissolved substances in water, be it drinking water, surface water, process water or wastewater, using a powdered adsorbent, which is used both in process preparations in the chemical industry and in water and wastewater technology, preferably drinking water treatment and wastewater treatment, and a device for carrying out this method. To adsorb the dissolved substances in the water, an adsorbent is used, in particular powdered activated carbon.

[0004] US Pat. No. 5,399,633 discloses a method for precipitating phosphate from phosphate-containing water using iron hydroxide.

[0005] US Pat. No. 5,399,633 describes a method and an apparatus for treating wastewater, in particular for removing small impurities in a purification plant comprising a reactor having an inlet opening for the wastewater, a contact zone in which granular activated carbon interacts with the wastewater, a supernatant zone and a subsequent outlet opening with purified wastewater.

[0006] A method for removing impurities from water, in particular from ground water and drinking water, is known from US Pat. No. 4,399,323, which method comprises: adding submicron range powdered activated carbon (sPAC) to the inflow of the water to be treated; mixing the sPAC with the water to be treated; introducing a mixture of sPAC and water into a sorption reactor for treatment; allowing the mixture to remain in the sorption reactor for a residence time sufficient to allow the sPAC to adsorb impurities in the water; using a return pump to transfer the mixture from the sorption reactor to a high rate ceramic membrane filter unit operating in cross-flow filtration, where the treated water is discharged as permeate and the sPAC is returned to the sorption reactor as retentate; Includes.

[0007] Patent document 5 relates to an adsorption system, in particular based on aggregates, comprising a plurality of adsorbent particles, which are fixed, in particular attached, to a binder carrier and connected to the adsorption system, in particular to the adsorbent, via the binder carrier, the adsorbent particles comprising a first particulate adsorbent material and a second particulate adsorbent material different from the first particulate adsorbent material. This type of adsorption system is used in the field of filter technology.

[0008] US Pat. No. 5,399,633 discloses an apparatus for treating aqueous liquids by contacting them with a fluidized bed of solidified carbon in powder form.

[0009] No. 5,399,633 describes a method for treating water to reduce the content of organic and harmful substances, the method comprising: a first step of contacting the water to be treated with a granular adsorptive material, the first step being carried out so that the contact time between the water and the granular adsorptive material is 5 to 20 minutes; then a second step of purifying the mixture of water and adsorptive material from the first step, obtaining purified water on the one hand and used granular adsorptive material on the other hand, In this case, the adsorbent material consists of agglomerates of activated carbon particles, the agglomerates having an average size of 20 μm to 1000 μm and an iodine value of more than 1000 mg / g.

[0010] Patent document 8 discloses a method for treating water with the aim of reducing the content of organic matter and harmful substances, which comprises the steps of contacting the water to be treated with an adsorbent granular material in a contact vessel equipped with an agitator, followed by a step of purifying the water emerging from the vessel, thus obtaining purified water and a slurry, the adsorbent granular material being composed of agglomerates of activated carbon particles, the agglomerates having an average size of 200 μm to 600 μm and an average size of 800 to 1000 μm. 2 / g.

[0011] Adsorbent structures based on agglomerates each comprising a plurality of granular, preferably spherical, adsorbent particles, the manufacture of these agglomerates and their use are described in WO 2005 / 023363. In this case, the adsorbent particles of the individual agglomerates are respectively interconnected via a preferably thermoplastic organic polymer, in particular a binder, or the adsorbent particles of the individual agglomerates are bonded and / or glued to a preferably thermoplastic organic polymer, in particular a binder. The adsorbent structures are used for adsorbing toxic substances, harmful substances and odors, in particular from gas or air streams or from liquids, in particular water.

[0012] US Pat. No. 5,399,633 describes a process for producing a filler-containing polymer-bonded support mass, the support mass obtained according to this process, and its uses. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] German Patent Application Publication No. 102013006985 [Patent Document 2] European Patent Application Publication No. 0530396 [Patent Document 3] European Patent Application Publication No. 3957608 [Patent Document 4] International Publication No. 2020 / 118513 [Patent Document 5] European Patent Application Publication No. 2536497 [Patent Document 6] European Patent No. 2440496 [Patent Document 7] European Patent Application Publication No. 3009405 [Patent Document 8] European Patent Application Publication No. 3231771 [Patent Document 9] European Patent No. 2349556 [Patent Document 10] European Patent Application Publication No. 0209790 Summary of the Invention [Problem to be solved by the invention]

[0014] It is an object of the present invention to provide an improved method for removing dissolved organic and / or inorganic materials from liquids using adsorbents. [Means for solving the problem]

[0015] This object is achieved according to the invention in that a water-soluble metering unit containing an adsorbent is metered into the liquid to be treated in order to remove the dissolved organic and / or inorganic substances in accordance with the amount of dissolved organic and / or inorganic substances to be removed, the adsorbent being released and the adsorbent being dispersed in a particle size d 50 The particle size of the powder adsorbent is 0.1 to 1000 μm, preferably 0.5 to 500 μm, and particularly preferably 1 to 100 μm.

[0016] In the form of a dosing unit, the sorbents are not associated with any risk of explosion. They can therefore be stored and handled without problems. When metered into the liquid to be treated, the dosing unit disintegrates or disperses the sorbents, which, due to their extremely large surface area, are able to bind large amounts of dissolved organic / inorganic substances.

[0017] A preferred, but not exclusive, field of use for the adsorbents is wastewater treatment, in particular in chemical / biological systems (membrane biosystems, SBR systems, single-stage or two-stage activated sludge processes, processes using aerobic and / or anaerobic granules, etc.) and / or in subsequent chemical / biological systems (such as what is known as the fourth purification stage).

[0018] A preferred embodiment of the present invention is that the adsorbent is selected from the group consisting of activated carbon, bentonite, zeolite, polymeric adsorbents, iron oxide, iron hydroxide, silica gel, or mixtures thereof.

[0019] In principle, any adsorbent capable of adsorbing dissolved, preferably organic / inorganic substances, is suitable. These may be, for example, anthropogenic organic trace substances (active pharmaceutical ingredients, X-ray contrast agents, substances from body care and cleaning products, biocides, flame retardants, perfluorinated chemicals, etc.), and / or organic carbon compounds, and / or inorganic substances such as phosphates, ammonium compounds or metals. The adsorbents may consist of activated carbon, bentonite, zeolites, polymeric adsorbents, iron oxides, iron hydroxides (such as β-FeOOH (akaganeite)) or silica gel, and mixtures thereof. The raw material of the adsorbent consists of substances present in powder and / or suspension form (for example in the case of activated carbon: powdered activated carbon (PAC) and / or superfine powdered activated carbon (sPAC)) and compatible with dissolved organic and / or inorganic substances or liquid matrices.

[0020] The dosing unit can be in the form of a pill made by pressing / freeze-drying / 3D printing / casting / extrusion of the powdered / suspended sorbent. Pills of this kind can be prepared from the powdered sorbent alone, for example by applying pressure / freeze-drying and / or by adding binders and / or disintegrants, which must be selected such that the sorbent is released upon contact with a liquid.

[0021] The dosing unit may also be in the form of a capsule, in which case a hard or soft water-soluble sheath encapsulates the powdered sorbent.

[0022] Similarly, the dosing unit may be in the form of a pod, with a hard or soft water-soluble sheath encapsulating the suspended adsorbent.

[0023] In this connection, it is also possible for the adsorbent to be present in foam form.

[0024] The shape, size and composition of the metering unit and its possible sheath are adapted so that the reaction between the sorbent in the liquid matrix and the substances to be removed proceeds optimally according to the respective process. The introduction of the metering unit can be carried out in the process chain, for example, at a position of high turbulence or high energy introduction, which favors the release and homogeneous distribution of the sorbent.

[0025] However, the time of release can also be intentionally controlled by the structure of the metering unit, for example by the choice of its sheath, so that a continuous dose of sorbent is achieved. One simply has to ensure that the metering unit disintegrates in contact with the liquid or the organic / inorganic substance. Process-related units (such as stirrers or disintegrators) can also be intentionally implemented or used to assist the release of the sorbent. Furthermore, the liquid to be treated can be pre-released externally or subsequently intentionally dosed into the process stream using a separate unit.

[0026] A development of the invention consists in a dosing unit which contains the additive.

[0027] In this context, according to the invention, the additive is selected from the group consisting of metal salts, iron oxides, iron hydroxides, polymers, and binders or disintegrants.

[0028] The additives serve in particular for the aggregation of the sorbent and for assisting its release after contacting the metering unit with the liquid, as well as for the settling and / or flotation and / or filtration of dissolved substances (phosphates, metals, etc.), and for separating the sorbent in separation processes such as precipitation, and / or for assisting the above-mentioned deposition processes.

[0029] A preferred embodiment of the present invention comprises metal salts including divalent or trivalent iron and aluminum salts.

[0030] Advantageously, the polymer is chosen from cationic, anionic and non-ionic polymers.

[0031] The binders (for agglomeration of the sorbent) or disintegrants (for aiding the release of the sorbent) are advantageously selected from biodegradable substances (polyvinyl alcohol, polyvinylpyrrolidone, gelatin, (microcrystalline) cellulose, carrageenan, starch, starch esters, glucose, lactose, saccharose, maltodextrin, polyacrylic acid, colloids, albumin, etc.) or non-biodegradable substances (salts, etc.). The binders or disintegrants are advantageously selected from readily biodegradable compounds. The readily biodegradable compounds can then serve as a nutrient source for downstream processes for separation, intended to support biological processes.

[0032] In the context of the present invention, the additives can be present both in crystalline and in powder form.

[0033] In the case of additives in solid form, the additive can be present in the form of an additive coating on the adsorbent, or a sheath of the adsorbent that dissolves upon contact with liquid, or it can be substantially homogeneously distributed throughout the adsorbent.

[0034] Alternatively, the additives may also be present in liquid and / or suspended form.

[0035] The scope of the present invention also covers a dosing unit for use in the method according to the present invention, the dosing unit being water-soluble and comprising at least one adsorbent selected from the group consisting of activated carbon, bentonite, zeolite, polymeric adsorbents, silica gel, or mixtures thereof, and at least one additive selected from the group consisting of metal salts, iron oxides, iron hydroxides, polymers, and binders or disintegrants, the adsorbent forming a hollow dosing unit encapsulating the additive.

[0036] Similarly, the scope of the invention also covers a dosing unit for use in the method, the dosing unit being water-soluble and comprising at least one adsorbent selected from the group consisting of activated carbon, bentonite, zeolite, polymeric adsorbents, silica gel, or mixtures thereof, and at least one additive selected from the group consisting of metal salts, iron oxides, iron hydroxides, polymers, and binders or disintegrants, the additive forming a hollow dosing unit encapsulating the adsorbent.

[0037] In the case of liquid additives, the hollow dosing unit may be formed from an adsorbent which encapsulates the liquid additive such that when the adsorbent is released, the liquid additive contained therein is also released.

[0038] Conversely, the sorbent may be present in liquid or foam form and encapsulated by a sheath of solid additive to form a dosing unit.

[0039] The invention also relates to a dosing unit for use according to the invention, which is water-soluble and comprises an adsorbent selected from the group consisting of activated carbon, bentonite, zeolite, polymeric adsorbents, silica gel, or mixtures thereof, and an additive selected from the group consisting of metal salts, iron oxides, iron hydroxides, polymers, and binders or disintegrants.

[0040] It is within the scope of the present invention for the additive to be present in powder form, preferably in the form of an additive coating on the adsorbent or in the form of a sheath of the adsorbent which dissolves on contact with liquid, or substantially homogeneously distributed throughout the adsorbent.

[0041] Alternatively, it may be advantageous for the additive to be present in liquid form, preferably with a hollow adsorbent encapsulating the liquid additive.

[0042] Example embodiments of the dosing unit are described in more detail below. 1. Dosing unit in pill form Adsorbent: PAC with 80% <40μm grinding fines; 500mg activated carbon / pill Additives: Polyvinylpyrrolidone, alginate Preparation of pills by compressing powdered sorbent mixed with additives under high pressure 2. Dosing unit in capsule form: Adsorbent: PAC with 80% <40μm ground powder; 100mg / capsule Bentonite with 80% ground powder <40μm; 100mg / capsule Additives: Gelatin Preparation: The additive is in the form of capsules that encapsulate the powdered sorbent. 3. Metering unit consisting of a sorbent coated with a water-soluble additive: Adsorbent: 〇sPAC with 80% <5μm ground powder; 200mg / capsule Bentonite with 80% ground powder <40μm; 50mg / capsule Additives: Polyvinyl alcohol; iron(II) chloride; starch Preparation: Pressing the powdered sorbent under high pressure and applying a coating of additives to the pressed sorbent

[0043] 1 to 5 show an embodiment of a dosing unit according to the invention. [Brief description of the drawings]

[0044] [Figure 1] 1 shows a dosing unit in the form of a pill. [Diagram 2] 1 shows a dosing unit in the form of a capsule. [Diagram 3] 1 shows a dosing unit in the form of an adsorbent / additive compound having a water-soluble sheath. [Figure 4] 1 shows a dosing unit in the form of an additive casing filled with liquid sorbent. [Diagram 5] 1 shows a foam sorbent / additive compound. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0045] As can be seen from FIG. 1, the dosing unit can be in the form of a pill prepared by compressing the sorbent 1, optionally with the addition of a binder and, optionally, further additives.

[0046] Figure 2 shows a dosing unit in the form of a capsule. This can be both a hard and a soft capsule. In this case, the powdered sorbent 1 is present in a capsule consisting of one or more water-soluble additives 2. On contact with water, the capsule dissolves and the sorbent 1 and the additive(s) 2 are released.

[0047] 3 shows a dosing unit in the form of a compound consisting of an adsorbent 1 and one or more solid additives 2, which compound is surrounded by a water-soluble sheath 3 as known from dishwasher tubs. The sheath 3 can also consist of further additives.

[0048] 4 shows a dosing unit in the form of a liquid sorbent 1 surrounded by a solid casing of one or more additives 2. Conversely, one or more liquid additives can also be surrounded by a solid casing of sorbent.

[0049] FIG. 5 shows that a foaming sorbent / additive compound may also be present.

Claims

1. Use of an adsorbent in a facility for treating liquids to remove dissolved organic matter, in which a water-soluble metering unit containing the adsorbent is metered into the liquid to be treated to remove dissolved organic and / or inorganic matter according to the amount of dissolved organic and / or inorganic matter to be removed, and the adsorbent is released, the adsorbent having a particle size d ５０ sorbent particles having a size of 0.1 to 1000 μm, preferably 0.5 to 500 μm, particularly preferably 1 to 100 μm.

2. 2. Use according to claim 1, characterized in that the adsorbent is selected from the group consisting of activated carbon, bentonite, zeolite, polymeric adsorbents, iron oxide, iron hydroxide, silica gel or mixtures thereof.

3. 3. Use according to claim 1 or 2, characterized in that the dosing unit contains an additive.

4. 4. The use according to claim 3, characterized in that the additive is selected from the group consisting of metal salts, iron oxides, iron hydroxides, polymers, and binders or disintegrants.

5. 5. The use according to claim 4, characterized in that the metal salts include divalent or trivalent iron and aluminium salts.

6. 5. The use according to claim 4, characterized in that the polymer is chosen from cationic, anionic and non-ionic polymers.

7. The use according to any one of claims 3 to 6, characterized in that the additive is present in solid form.

8. 8. The use according to claim 7, characterized in that the additive is present in the form of an additive coating on the sorbent or in the form of a sheath of the sorbent which dissolves on contact with a liquid, or alternatively is substantially homogeneously distributed in the sorbent.

9. Use according to any one of claims 3 to 6, characterized in that the additive is present in liquid form.

10. 10. Use according to claim 9, characterised in that a hollow adsorbent is present which encapsulates the liquid additive.

11. 11. A dosing unit for use in the method according to any one of claims 1 to 10, characterized in that the dosing unit comprises at least one adsorbent (1) which is water-soluble and selected from the group consisting of activated carbon, bentonite, zeolite, polymeric adsorbents, silica gel or mixtures thereof, and at least one additive (2) which is selected from the group consisting of metal salts, iron oxides, iron hydroxides, polymers and binders or disintegrants, the adsorbent (1) forming a hollow dosing unit encapsulating the additive (2).

12. 11. A dosing unit for use in the method according to any one of claims 1 to 10, characterized in that the dosing unit comprises at least one adsorbent (1) which is water-soluble and selected from the group consisting of activated carbon, bentonite, zeolite, polymeric adsorbents, silica gel or mixtures thereof, and at least one additive selected from the group consisting of metal salts, iron oxides, iron hydroxides, polymers and binders or disintegrants, the additive (2) forming a hollow dosing unit encapsulating the adsorbent (1).

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