CZ202186A3 - Method of producing and using carbon-based sorbent - Google Patents

Abstract

The method of producing a carbon-based sorbent consists in the fact that raw wood without bark with a dry matter content of 60 to 90 wt.% maintains for 20 to 60 min. at a temperature of 580 to 780 °C in an environment with a lack of air, the resulting carbonaceous material is heated for at least 10 min. exposed in an inert environment under a pressure of 0.1 to 5 bar (0.01 to 0.5 MPa) to the action of water vapor at a temperature of 100 to 150 °C and subsequently ground into particles with a size of up to 10 µm.

Description

Method of production and use of carbon-based sorbent

Field of technology

The invention relates to a sorbent for the purification of wastewater, polluted in particular by industrial chemicals, petroleum hydrocarbons, pharmaceuticals and their metabolites, hormones and similar modern pollutants, or agrochemicals, such as pesticides, herbicides or industrial fertilizers.

Current state of the art

Wastewater pollution by chemical substances and hydrocarbons from industrial operations is mostly removed by chemical precipitation using coagulants. In addition to insufficient efficiency, the main problem with this method is the generation of a significant amount of hazardous waste in the form of sludge. In addition, the greater part of this waste is created for no reason, because often the concentration of pollution in the wastewater is less than the limit, but due to the non-existent measurement at the entrance of the treatment plant, chemical precipitation takes place continuously.

Pollution by agrochemicals mainly affects surface water, watercourses and groundwater, which after the necessary treatment are used as drinking water. However, most treatment plants are not equipped to remove these substances. If so, filtration through activated carbon is usually used. The effectiveness of removing pesticides with activated carbon is usually sufficient, but the costs of the filter cartridge are relatively high.

Modern pollutants, especially pharmaceuticals, their residues and metabolites, as well as hormonal substances, have not yet been essentially removed from wastewater. Sewage treatment plants are not prepared for this type of pollution. At the same time, information about the serious impacts of pharmaceuticals contained in wastewater on local ecosystems has been appearing more and more frequently.

The invention sets itself the task of designing a method of producing a carbon-based sorbent intended for the adsorption of pollutants from liquids and methods of its use.

The essence of the invention

The mentioned task is fulfilled by the method of producing a carbon-based sorbent, which consists in the fact that raw wood without bark with a dry matter content of 60 to 90 wt. maintains for 20 to 60 min. at a temperature of 580 to 780 °C in an environment with a lack of air, the resulting carbonaceous material is heated for at least 10 min. exposed in an inert environment under a pressure of 0.1 to 5 bar (0.01 to 0.5 MPa) to the action of water vapor at a temperature of 100 to 150 °C and subsequently ground into particles with a size of up to 10 pm.

To increase the sorption effect of the resulting sorbent, the ground carbonaceous material is poured with a mixture of H2SO4 and HNO3, and after cooling in a water bath at a temperature of 5 to 10 °C, it is exposed to the action of KCIO3, followed by washing with distilled water and separation of the sorbent by drying, sedimentation or filtration.

To increase the oxidation effect, the water bath after the addition of KCIO3 is heated to a temperature of 45 to 55 °C and stirred for at least 5 hours.

The sorbent created in the above-mentioned manner is used for wastewater treatment by creating a solution with a composition of 0.1 to 20 mg of sorbent per 1 liter of wastewater, which is left for 10 to 50 min. stirs intensively, after which the sorbent is filtered from the solution.

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The sorbent can be used to create a filter for wastewater treatment by creating a solution with an organic solvent in the ratio of 0.5 to 20 mg of sorbent per 1 ml of organic solvent, a non-woven fabric with a density of 100 to 300 g/m ² is immersed in the solution. 10 to 30 mg of sorbent will fall on 1 cm ² of its surface, after which, after complete absorption of the solution into the fabric, the excess of the liquid phase is filtered off and the remaining liquid is evaporated, and then the surface of the dried fabric is ironed on both sides at a temperature of 150 to 200 °C. Filter fabric with carbon sorbent intended for the production of filter inserts for flow filters of various types is produced in the described manner.

The filter can also be created by mechanically applying a dry sorbent to a non-woven fabric with a density of 50 to 100 g/m ² , which is inserted between two clean non-woven fabrics with a density of 10 to 200 g/m ² and laminated together at a temperature of 100 to 200 °C for at least 10 seconds.

The sorbent can also be used to create a nanofibrous membrane for wastewater treatment by adding it to a bath of polymer ready to be spun and spinning the polymer, with the nanofibers forming the membrane.

The carbon sorbent produced and applied in this way removes pollutants from water using the principle of chemisorption. The process of chemisorption can be characterized by the formation of a chemical bond between the pollutant molecule and the active surface of the sorbent on which there are functional groups, for example COOH, -OH, -NH2 and the like. In addition to filter fabric, the sorbent can be used to make a nanofiber filter membrane by mixing the sorbent with a polymer to be spun, and then spinning to form a nanofiber membrane.

The filter fabric or membrane can then be combined with other filter materials, for example a filter membrane for removing mechanical impurities or bacteria. If the filter fabric or membrane is intended for the removal of pesticides, it can be advantageously combined with a filter material containing iron metals or their ions.

Clarification of drawings

Giant. 1 - sorption properties of sorbent B-4073 - its IR spectrum.

Giant. 2 - sorption properties of sorbent B-4073-OXO - its IR spectrum.

Giant. 3 - dependence of sorption on time.

Giant. 4 - dependence of sorption on sorbent concentration.

Examples of implementation of the invention

Examples of sorbent production

Example 1

Made of spruce wood with a dry matter content of 70% by weight. a carbonaceous material was produced at a temperature of 745 °C and an exposure time of 54 minutes, which was for 15 min. exposed at a pressure of 2 bar (0.2 MPa) to the action of steam at a temperature of 130 °C and subsequently crushed on a jaw crusher to a particle size of 0.2 to 8 mm. The crushed material was then ground on a pin mill with four passes.

The powder sorbent produced in this way was designated B-4073.

The average particle size determined by sieve analysis of 100 grams was determined to be 0.09 mm. The heat of combustion of B-4073 was found to be 31.635 MJ/kg.

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The specific surface area of B-4073 was determined by BET analysis to be 571.6 ± 9.2 m ² /g. The volume of the monomolecular layer was found to be 131.3 cm ³ /g. The area of micropores is equal to 325.7 m ² /g, while mesopores and macropores together form a surface of 245.9 m ² /g. The largest distribution of mesopores was 2 and 7 nm, for micropores 1.05 nm. The total volume of mesopores was found to be 0.189 cm ³ /g, for micropores 0.247 cm ³ /g.

By analyzing the FT-IR spectrum of the B-4073 sorbent, the binding vibrations of the functional groups OH (3400 cm ¹ ), CH (2900 cm ¹ ), CO, COC (1050 cm ¹ ) in the intervals 1300 to 1900 cm ¹ (C=O, C =C, -COO-).

Sorptive properties of sorbent B-4073 - its IR spectrum is shown in the diagram in Fig. 1

A Titrino 795 titrator would also be used to determine the functional groups. The titration was performed with a solution of NaOH and HC1 with a concentration of 0.1 mol/1. From the measured results, the content of -OH groups was calculated to be 0.386 ±0.02 mmol/g.

Furthermore, an elemental analysis was carried out to determine the content of carbon (82.03%), hydrogen (0.74%) and oxygen (16.96%).

Example 2

Modification of sorbent B-4073

A portion of B-4073 (3.48 g) was layered in an Erlenmeyer flask with 40 ml of H2SO4 + 20 ml of HNO3. This suspension was stirred with a magnetic stirrer for 1 h, then cooled in an ice water bath (5 to 10 °C) and KCIO3 (18 g) was added in small portions (20 min). The temperature was gradually increased to 35 to 55 °C after the addition of chlorate. At this temperature, the reaction mixture was stirred for 10 hours, then left to stand for 4 days in a resting state. The mixture was dissolved in 120 ml of distilled water and followed by a 10x repeated centrifugation process followed by decantation (the colloidal solution was decanted above the sediment). After decanting, the sediment was washed with distilled water and the process was repeated. The thickened water suspension was dried for 2 days at 60 to 70°C. In the spectrum that characterizes the course of thermal decomposition, 3 temperature ranges with more significant weight losses of the sample can be identified, i.e. 50 to 130 °C (17.4% loss), 130 to 300 °C (18.7%), 300 to 400 °C ( 20.8%). This cascading gradual decomposition results in a sharp exoeffect with a maximum at 425 °C (44% loss) with a thermal coloration of 13.0 kJ/g.

The powder sorbent produced in this way was labeled B-4073-OXO.

The sorption properties of the B-4073-OXO sorbent - its IR spectrum is shown in the diagram in Fig. 2.

Testing the sorption capacities of sorbents B-4073 and B-4073-OXO.

Sorption of NEL (hydrocarbons C10 - C40).

From the industrial wastewater (COV) of the refinery Slovnaft, a.s. with headquarters in Bratislava (rafinerskopetrochemicka společnost) was selected for the tests the level of wastewater treatment - Mechanical level of VSTUP treatment. The sample was processed in the laboratories of Slovnaft a.s., tests were performed to determine CHSKCr - chemical oxygen consumption (oxidizing agent dichroman) and to determine NEL - non-polar extractable substances.

B-4073 sorbents were used. B-4073-OXO and activated carbon for chromatography 0.3 to 0.5 mm Merck (AU), in weights per 1 liter of wastewater 0.3; 0.5; 0.7; 1.0; 1.5 and 1.7 grams. Individual mixtures of wastewater and B-4073, B-4073-OXO or AU were mixed and mixed for 2 hours on a shaker at 280 rpm (Heidolph Promax 2020), then the mixtures were filtered through a paper filter and

-3 CZ 2021 - 86 A3 analyzes were performed on the filtrate. We obtained a mass sorption curve (related to the ratio of the amount of waste water/B-4073, B-4073-OXO or AU). Using the same procedure, we also measured the time dependence of the weight of 1 g of sorbent. For selected batches, the obtained filter cakes were dried for five days at laboratory temperature, and after removal from the filter paper, their analysis was followed by FT-IR and TGA, 5 DSC.

COD and NEL results of the wastewater sample before and after sorbing B-4073, B-4073-OXO and AU

Sample CHSKCr NO mg02/l Efficiency 0/ /0 mg/1 Efficiency 0/ /0 Mechanical stage - input 142 0 18.6 0 1. Mechanically grade - input + 0.3g B-4073 49 65.5 0.18 99.0 2. Mechanical grade - input + 0.5g B-4073 50 64.8 0.20 98.0 3. Mechanical stage - input + 0.7g B-4073 44 69.0 0.28 98.5 4. Mechanical stage - input + l.0g B-4073 33 76.8 0.18 99.0 5. Mechanical stage - input + l.5g B-4073 29 79.0 0.32 98.3 6. Mechanical stage - input + l.7g B-4073 22 84.5 0.13 99.3 1. Mechanical stage - input + 0.3g B-4073-OXO 45 68.3 0.15 99.2 2. Mechanical stage - input + 0.5g B-4073-OXO 48 66.2 0.19 99.0 3. Mechanical stage - input + 0.7g B-4073-OXO 40 71.8 0.22 98.8 4. Mechanical stage - input + 1.0g B-4073-OXO 35 75.3 0.20 98.9 5. Mechanical stage - input + 1.5g B-4073-OXO 27 80.9 0.25 98.6 6. Mechanical stage - input + 1.7g B-4073-OXO 25 82.4 0.19 99.0 1.Mechanical stage - input + 0.3g AU 90 36.6 4.40 76.3 2.Mechanical stage - input + 0.5g AU 85 40.1 3.17 83.0 3.Mechanical stage - input + 0.7g AU 81 42.0 4.30 76.9 4.Mechanical stage - input + l.0g AU 44 69.0 1.86 90.0 5.Mechanical stage - input + l.5g AU 37 73.9 2.37 87.3 6.Mechanical stage - input + l.7g AU 42 70.4 3.65 80.4 Mechanical stage - input + l.0g B-4073 l.t - lOmin 36 74.6 0.65 65.1 2.t - 20 min 36 74.6 0.32 82.8 3.t - 30 min 31 78.2 0.15 99.2 4th t - 40 min 34 76.1 0.31 98.3 5th t - 50 min 26 81.7 0.27 98.5 6.t - 60 min 36 74.6 0.29 98.4

io For oxygen sorption - chemical oxygen consumption (CHCOCr), which indicates the total content of organic (oxidizable) substances in water, the efficiency for B-4073 was a maximum of 84.5%, for B-4073-OXO a maximum of 82.4%, in both cases, thus higher than for AU and which reached a maximum value of 73.9%.

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For non-polar extractables (NEL) sorption for both B-4073 and B-4073-OXO weight series, the efficiency was nearly 100% (98.0 to 99.8%) and was higher than AU weight series. The oxygen sorption efficiency values of AU are variable and reached a maximum value of 90.0%. The NEL sorption efficiency results as a function of time change were investigated for B-4073 and they increase within 30 min, then stabilize and the sorption efficiency was almost 100%.

Sorption of toluene C-H»

As part of laboratory testing, four samples were prepared, three containing 50 ml of toluene solution and 300 mg of sorbent, the fourth was a blank sample. All samples were shaken for one hour at 250 rpm and all but the blank were subsequently filtered.

Exact description below:

• Blank test - 50 ml of toluene solution • B-4073 - 50 ml of solution and 300 mg of sorbent B-4073 • B-4073-OXO - 50 ml of solution and 300 mg of B-4073-OXO • GO - BI 1:1 - 50 ml of solution and 300 mg of B-4073 + graphene oxide in a ratio of 1:1

Results:

Sorbent Result [mg/11 Sorbent efficiency [%] Sorptive capacity |mg/gl Blind attempt 540 on on B-4073 60 88,89 80.00 B-4073-0X0 50 90.74 81.67 GO - BI 1:1 40 92.59 83.33

The results demonstrate the high sorption efficiency of all selected sorbents. The best result is shown by modified B-4073 with graphene oxide (GO - BI) 1:1, which has an efficiency of 92.59%. The value of the sorption capacity is more telling in this case, because with the highest value of 83.33 mg/g, all samples stay below the average.

Removal of total pollution (as CODcr)

The tests were carried out on wastewater from the production of fish delicacies. The main components of pollution are salt, vinegar, milk fats, animal and fish fats, gelatin and collagen. The samples were collected after a mechanical fat separator.

Three experiments were performed, each with a different dose of B-4073 sorbent. All were performed by directly dosing the sorbent into the polluted water and stirring for various times at a speed of 700 rpm. Subsequently, the water was filtered through filter paper.

Experiment #1 - Z1

Dose of sorbent B-4073-OXO 1.5 g per 1 1 of water.

Six variants of contact time Z1-10 = 10 minutes to Z1-60 = 60 minutes have been implemented.

Experiment #2 - Z2

Dose of sorbent B-4073 2 g per 1 liter of water.

Six variants of contact time Z2-10 = 10 minutes to Z2-60 = 60 minutes have been implemented.

Experiment No. 3 - Z1

The dose of sorbent B-4073 is 3 g per 1 liter of water.

Six variants of contact time Z3-10 = 10 minutes to Z3-60 = 60 minutes have been implemented.

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Results of CODCr removal from food production wastewater:

Experiment CODcr (mg/1) Efficiency Water withdrawal 14850 on Zi-io 4100 72.4% Zl-20 3850 74.1% Zl-30 3900 73.8% Zl-40 3800 74.4% Zl-50 4000 73.06% Zl-60 3900 73.8% Z2-IO 3900 73.8% From ₂ -20 3860 74.0% Z2-3O 3860 74.0% Z2-4O 3860 74.0% Z2-5O 3460 76.7% Z2-6O 3860 74.0% Z3-IO 6510 56.1% Z3-20 6060 59.2% Z3-30 6160 58.6% Z3-40 6110 58.9% Z3-50 6310 57.5% Z3-6O 6210 58.2%

The highest total CODcr removal value was achieved at a dose of sorbent B-4073 of 2 g per 1 1 of water, practically the same in all variants - 73.8 to 76.6%.

Removal of drugs and their metabolites

For testing, water was taken from the COV, in which the drugs were determined. From the obtained data, several analytes were selected for sorbent testing, and four analytes (Diclofenac, Tramadol, Clarithromycin, Sulfamethoxazole) were selected for sorption capacity testing and to understand reactivity to the sorbent.

To determine the efficiency of analyte removal, two doses of sorbent B-4073 were chosen, namely 0.5 g/1 1 and 1 g/1 1. COV water was added to the weighed B-4073 and in time intervals of 30, 60 and 180 minutes it was gradually water sample taken for analyte determination by LC-MS.

The results are shown in the table. It can be seen that after 30 minutes and a weight of 0.5 g per liter, 85% of the original analyte concentration is already removed, and after 3 hours, on average, 95% of the original analyte concentration is removed. Once the dosage is doubled, almost 100% effectiveness is achieved after 30 minutes.

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Weight B-40731 0.5g/11) Weight B-4073 1 g/11) Analyte Origin conc. (ng/1) t 30 odstr. (%) t 60 odstr. (%) t 180 odstr. (%) t 30 odstr. (%) t 60 odstr. (%) t 180 odstr. (%) 4-Hydroxydiclofenac 263 78.0 89.1 91.0 97.6 97.2 98.3 Carbamazepine 332 90.5 94.9 95.3 97.0 96.9 96.6 Clarithromycin 723 87.1 92.9 94.0 95.8 95.8 95.6 Diclofenac 1576 88.3 92.3 94.2 97.3 97.5 98.0 Ketoprofen 300 81.0 89.5 92.6 95.3 96.4 97.3 Pentoxifylline 85 90.1 93.7 94.7 95.3 95.2 95.3 Phenazone 103 73.1 84.0 90.6 100.0 91.8 100.0 Sulfamethoxazole 175 49.0 44.1 72.6 81.4 83.0 87.6 Tramadol 352 91.3 94.5 95.6 97.5 96.9 97.2 Trimethoprim 50 85.1 88.2 88.9 90.1 89.8 89.8 Venlafaxine 233 84.5 90.2 93.5 97.1 96.0 96.0

Four analytes were tested for sorption tests - Diclofenac, Tramadol, Clarithromycin, Sulfamethoxazole. Since Clarithromycin immediately reacted with the sorbent during the sorption capacity testing, another analyte was selected - Carbamazepine, which is also widely present in wastewater. During the testing, rapid sorption occurred again, so it was only possible to measure the kinetics of sorption (shown in the graph) and the effect of sorption efficiency in the case of pink weighing. The measured data showed that sorption of the analyte occurs after 5 to 10 minutes, when at least 50% of the analyte is absorbed. With Clarithromycin, there is no gradual sorption, but an immediate reaction to the sorbent, which is due to the size of the molecule of this analyte and the large number of functional groups that this drug has.

The graph in Fig. 3 shows the dependence of sorption on time. The graph in Fig. 4 shows the dependence of sorption on the concentration of the sorbent. The graph shows that even when a small amount of sorbent (0.05 g/1) is used, sorption of the tested analytes occurs. In order to achieve the maximum removal of the tested analytes, it is enough to use 0.5 to 1 g/1 sorbent. The results apply to the tested concentrations of four drugs.

Examples of filter textile production

Option 1.

From the carbonaceous sorbent produced by the procedure described above and mixed with methanol, three variants of the solution a) containing 100 mg of B-4073-OXO in 10 cl of methanol, b) containing 250 mg of B-4073 in 10 cl of methanol, c) containing 400 mg of B -4073 in 10 cl methanol.

BASTELFILZ non-woven fabric with a density of 150 g/m ² and an area of 10 cm ² was subsequently immersed in all variants. After complete soaking of the solution on the textiles, the excess liquid was pressed out mechanically between two pressure rollers and the remaining liquid was evaporated on a hot plate at a temperature of 75 °C. The surface of the dried fabric was ironed on both sides with a pressure plate at a temperature of 195 °C and a pressure of 2 Pa.

In this way, four types of filter fabric were prepared, containing sorbent in amounts A - 10 mg/cm ² , B - 25 mg/cm ² , C - 40 mg/cm ² , D - 50 mg/cm ² .

Variant 2. The carbon sorbent B-4073-OXO, produced by the above-mentioned procedure, was taken away and applied to the needle-punched textile material 80 g/m ² (VP). The applied amount of sorbent B-4073-OXO corresponded to 25 mg/cm ² . Homogenization took place by machine application and then by brush. Subsequently, the injected fabric was folded over and a meltblown fabric was inserted in the middle

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180 g/m2 ⁽ MB). Both fabrics were subsequently covered on both sides with a spunbond type fabric 18 g/m ² (SB) and this layered fabric was laminated at a temperature of 130 °C for 14 seconds without pressure. The fabric sample was labeled D - 25 mg - B-4073-OXO.

Removal of pharmaceuticals and their metabolites by passing through filter fabrics

A-10 mg (OXO), B-25 mg and C-40 mg fabric filters cut into CHROMABOND columns. A drug solution was prepared for testing, which was allowed to drip freely through columns with a cut-out filter made of fabric with different sorbent content, the volume of the solution for sorption was 10 ml. With a filter containing 40 mg of sorbent, spontaneous dripping no longer occurred, so a slight negative pressure was used and the dripping rate was set to 0.4 ml/min. The amount removed on individual filters is shown in the table:

Analyte origin conc. (ng/1) A-10 mg OXO (%) B-25 mg (%) C-40 mg (%) 17-α-ethynylestradiol 927 ±92.7 100 100 100 3-hydroxy carbamazepine 9209 ±921 96.8 86.1 99.7 Acebutolol 9993 ±999 95.0 94.1 95.7 Acetylsulfadiazine 8744 ± 874 78.0 55.6 95.9 Amidotrizoate 9459 ±946 52.1 24.8 91.7 Bisphenol A 6619 ±662 82.3 82.6 89.7 Carbamazepine 10035 ± 1004 94.8 86.9 96.7 Clarithromycin 28702 ±2870 98.5 98.7 98.1 Diclofenac 1587 ± 159 69.4 15.1 87.1 Estriol 7086 ±709 97.8 96.8 98.6 lopamidol 7622 ±762 86.8 64.3 97.3 V-Acetylsulfamethoxazole 8771 ± 877 97.5 87.9 100 V-Acetylsulfapyridine 9196 ±920 93.8 78.1 98.2 Pentoxifylline 8974 ± 897 93.0 89.8 94.3 Phenazone 9587 ±959 78.5 49.7 99.2 Propranolol 7683 ±768 95.4 95.5 100 Sotalol 10115 ± 1012 87.0 64.9 96.9 Sulfadiazine 9116 ±912 84.9 56.5 96.8 Sulfamerazine 8832 ± 883 62.0 28.4 92.3 Sulfamethoxazole 9333 ±933 32.5 24.5 85.6 Sulfapyridine 10528 ± 1053 83.7 64.1 97.3 Tramadol 10391 ± 1039 94.6 87.6 97.0 Trimethoprim 11578 ± 1158 97.0 92.2 98.8 Venlafaxine 8471 ± 847 93.4 84.6 96.3

The filter fabric with a content of 40 mg of sorbent per 1 cm ² shows almost one hundred percent efficiency in removing the most common types of pharmaceuticals and their metabolites.

Testing filter fabric for gas penetration

The filter fabric produced according to variant B., marked D - 25 mg - B-4073-OXO was tested according to the test according to ČSN EN 149:2002 + A 1:20009 Respiratory protective devices.

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During the tests, the following devices were used: test device for determining breathing resistance INSPEC, Manometer GDH 200-07, rotameter Yokogawa P052, rotameter Yokogawa P161, stopwatch Ruhla, thermometer type Centigrade 0.1, device for testing paraffin oil aerosol filters LORENZ type BIA, device for testing with NaCl aerosol by MOORE'S type 1100.

The metrological security of the devices is carried out in accordance with the VÚBP-ZL metrological regulations.

Filter fabric D - 25 mg - B-4073-OXO Breathing resistance (Pa) at 30 1/min at 95 rpm 398 1345 Paraffin oil penetration after 3 minutes, flow rate 95 1/min 2.8% NaCl penetration after 3 minutes, flow rate 45 1/min 1.23% YPERIT contamination 5 x 0.5 pl drops Fries > 20 hours > 20 hours

Example of manufacturing a filter membrane from nanofibers with carbon sorbent B-4073.

A spinning machine of the NANOSPIDER type was used for production - electrostatic spinning from the polymer surface. PVDF polymer (VDF-HFP copolymer) was used.

Variant A

30 wt.% was added to the polymer solution. B-4073 (per polymer solids).

Measured parameters Properties Measured value Unit Method description Basic material 6.30 gsm division and weighing of NF material Fiber diameter 83 n.m SEM image analysis Filtration efficiency 87 0/ /0 testing area 100 cm ² , NaCl aerosol, 5 m/min, on PALAS/TOPAS test equipment Air permeability 0.9 m ³ /m ² /min testing area 100 cm ² /200 Pa - Textest 3300 Bubble point kPa PMI capillary flow porometer Sample size lOx 10 cm

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Option B

10% by weight was added to the polymer solution. B-4073 (per polymer solids).

Measured parameters Properties Measured value Unit Method description Basic material 7.25 gsm division and weighing of NF material Fiber diameter 91 n.m SEM image analysis Filtration efficiency 69 0/ /0 testing area 100 cm ² , NaCl aerosol, 5 m/min, on PALAS/TOPAS test equipment Air permeability 1.9 m ³ /m ² /min testing area 100 cm ² / 200 Pa - Textest 3300 Bubble point kPa PMI capillary flow porometer Sample size lOx 10 cm -

Claims (7)

PATENT CLAIMS 1. A method of producing a carbon-based sorbent, characterized in that raw wood without bark with a dry matter content of 60 to 90 wt.% maintains for 20 to 60 min. at a temperature of 580 to 780 °C in an environment with a lack of air, the resulting carbonaceous material is heated for at least 10 min. exposed in an inert environment under a pressure of 0.1 to 5 bar (0.01 to 0.5 MPa) to the action of water vapor at a temperature of 100 to 150 °C and subsequently ground into particles with a size of up to 10 pm. 2. The method of producing a carbon-based sorbent according to claim 1, characterized in that the carbonaceous material after grinding is covered with a mixture of H2SO4 and HNO3 and after cooling in a water bath at a temperature of 5 to 10 °C it is exposed to the action of KCIO3 followed by washing with distilled water and separation of the sorbent by drying, sedimentation or filtration. 3. The method according to claim 2, characterized in that the water bath is heated to a temperature of 45 to 55°C after the addition of KCIO3 and stirred for at least 5 hours. 4. The use of a sorbent created by the method according to one of claims 1 to 3 for wastewater treatment by creating a sorbent solution with a composition of 0.1 to 20 mg of sorbent per 1 1 of wastewater, which is allowed to stand for 10 to 50 min. stirs intensively, after which the sorbent is filtered from the solution. 5. Use of the sorbent produced by the method according to one of claims 1 to 3, to produce a filter for wastewater treatment by creating a solution with an organic solvent in a ratio of 0.5 to 20 mg of sorbent per 1 ml of organic solvent, a non-woven fabric is immersed in the solution fabric with a density of 100 to 300 g/m ² , 10 to 30 mg of sorbent per 1 cm ² of surface, after which, after the solution has been completely absorbed into the fabric, the excess liquid phase is filtered off and the remaining liquid is evaporated, and then the surface of the dried fabric is ironed on both sides at a temperature of 150 to 200 °C. 6. Use of the sorbent produced by the method according to one of claims 1 to 3, for the production of a filter for wastewater treatment by mechanically applying the dry sorbent to a non-woven fabric with a density of 50 to 100 g/m ² , which is inserted between two clean non-woven fabrics with a density of 10 to 200 g/m ² and are laminated together at a temperature of 100°C to 200°C for at least 10 seconds. 7. Use of a sorbent produced by a method according to any one of claims 1 to 3, to form a nanofibrous membrane for wastewater treatment by adding the sorbent to a polymer bath ready for spinning and spinning the polymer, whereby the nanofibers form a membrane.