USE AND METHOD FOR REDUCING THE VIRAL, BACTERIAL AND FUNGAL SPORE LOAD OR OTHER BIOLOGICAL CONTAMINANTS IN GASES

Abstract

The present invention relates to the use of an ion exchanger for the removal and/or reduction of biological contaminants, such as viruses, bacteria and fungal spores, in gases and gas streams, such as room air and breathing air, and a corresponding method. In certain embodiments, the ion exchanger is a cation exchanger partially or substantially completely loaded with H.sup.+ ions or an anion exchanger partially or substantially completely loaded with OH.sup.− ions. Additionally or alternatively, the ion exchanger may be loaded with transition metal ions, such as titanium, copper and/or silver ions.

Claims

1. Use of one or more ion exchangers for the reduction and/or removal of biological contaminants in gases and/or gas streams.

2. The use according to claim 1, characterized in that the biological contaminants are selected from the group consisting of viruses, bacteria, molds, fungal spores, mites, mite residues, mite droppings, pollen, and fragments of the foregoing, metabolites such as mycotoxins, proteins, RNA and DNA, preferably selected from the group consisting of enveloped viruses, non-enveloped viruses, bacteria, fungal spores and proteins and particularly preferably selected from the group consisting of coronaviruses, SARS-type viruses, SARS-CoV-2 viruses, resistant pathogens and multi-resistant pathogens.

3. The use according to claim 1, characterized in that the ion exchanger comprises at least one cation exchanger, optionally the cation exchanger being at least one of a weakly acidic cation exchanger, a strongly acidic cation exchanger, or a mixture thereof.

4. The use according to claim 3, characterized in that the cation exchanger is partially or substantially completely loaded with H+ ions.

5. The use according to claim 1, characterized in that the ion exchanger is selected from the group consisting of anion exchangers, mixed anion and cation exchangers, cation exchangers loaded with transition metal ions, ion exchangers bearing chelate ligands, mixtures thereof and mixtures thereof with cation exchangers, wherein preferably the anion exchanger is partially or substantially completely loaded with OH− ions.

6. The use according to claim 5, characterized in that the ion exchanger is at least one cation exchanger loaded with transition metal ions, wherein the transition metal ions are selected from the group consisting of cations of Ti, V, Cr, Mo, W, Mn, Fe, Ru, Co, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg, Pb, Ge, Sn, Al, or a lanthanide, and mixtures thereof, and preferably are selected from the group consisting of cations of copper, silver, titanium and mixtures thereof.

7. The use according to claim 1, characterized in that the ion exchanger is present in solid form, preferably as an organic ion exchanger and more preferably as a synthetic resin ion exchanger, wherein the ion exchanger may be present in particulate form, as a flow-through fill and/or as an insert in a mouth-nose protection.

8. The use according to claim 1, characterized in that the ion exchanger further comprises hygroscopic auxiliary agents and/or hygroscopic functional groups.

9. The use according to claim 1, characterized in that the gases and/or gas streams are air and/or air streams, preferably selected from the group consisting of room air, room air streams and breathing air streams, wherein the room air and room air streams are preferably selected from room air and room air streams in shelters, motor vehicle interiors, air-conditioned rooms, cabins, airplanes, emergency vehicles, truck cabs, vehicles of security forces, respiratory equipment, intensive care units, staff rooms, rooms for animal husbandry and other rooms in which people, animals or plants are present or located.

10. The use according to claim 1, characterized in that the ion exchanger is designed as a filling of a hollow body and/or as a porous molded body, the hollow body and/or the molded body preferably being inserted or incorporated into or connected to a respiratory mask.

11. The use according to claim 1 in combination with one or more of the methods selected from the group consisting of filtration, humidification, drying, condensation, UV treatment, corona or plasma treatment, high voltage treatment, radioactive radiation treatment, treatment by heating and treatment by cooling.

12. Method for the removal and/or reduction of biological contaminants in gases and gas streams by means of one or more ion exchangers, characterized in that the gases or gas streams are brought into contact with an ion exchanger.

13. The method according to claim 12, characterized in that the biological contaminants are selected from the group consisting of viruses, bacteria, molds, fungal spores, mites, mite residues, mite droppings, pollen, and fragments of the foregoing, metabolites such as mycotoxins, proteins, RNA and DNA, preferably selected from the group consisting of enveloped viruses, non-enveloped viruses, bacteria, fungal spores and proteins and particularly preferably selected from the group consisting of coronaviruses, SARS-type viruses, SARS-CoV-2 viruses, resistant pathogens and multi-resistant pathogens.

14. The method according to claim 12, characterized in that the ion exchanger comprises at least one cation exchanger, optionally the cation exchanger being at least one of a weakly acidic cation exchanger, a strongly acidic cation exchanger, or a mixture thereof, and wherein the cation exchanger preferably is partially or substantially completely loaded with H+ ions.

15. The method according to claim 12, characterized in that the ion exchanger is selected from the group consisting of anion exchangers, mixed anion and cation exchangers and mixtures of anion and cation exchangers, wherein preferably the anion exchanger is partially or substantially completely loaded with OH− ions.

16. The method according to claim 12, characterized in that the ion exchanger is designed as a filling of a hollow body and/or as a porous molded body, preferably the hollow body and/or the molded body being inserted or incorporated into or connected to a respiratory mask.

17. The method according to claim 12, wherein additionally one or more methods selected from the group consisting of filtration, humidification, drying, condensation, UV treatment, corona or plasma treatment, high voltage treatment, radioactive radiation treatment, treatment by heating, treatment by cooling, ozonization, dosing of gases or liquids for treatment of the ion exchanger and/or the gas, in particular air, are carried out, wherein the method or methods are preferably carried out permanently or at intervals.

Description

EXAMPLES

Example 1. Aerosol Retention Capacity

[0173] The present example illustrates the ability of the ion exchangers of the invention to retain aerosols. As a model medium for potentially virus-containing aerosols, an aerosol of a 0.9 wt. % sodium chloride solution, which is close in salt content to sneezing or coughing secretion, is used.

[0174] It is generally known that the transmission of viruses and bacteria in air currents mostly takes place in the form of aerosols, i.e. finely dispersed water droplets that can float in the air due to their size. In sizes of <5 μm, aerosols are respirable, i.e. may access the lungs. The generation of such aerosols containing human pathogens is difficult due to the high safety requirements. In biological laboratories, a variety of measures are taken to prevent the formation of aerosols. Common aerosol generators are also not designed for operation under safety cabinets or in glove boxes or too large. In this respect, a compact system was developed to demonstrate the retention of biological substances in model aerosols by ion exchangers according to the invention.

[0175] Aerosol is generated via a Pari Boy® Pro inhalation system. The system uses a compressor to generate an air flow of 3-6 l/min at 0.6-1.9 bar. With one nozzle (used: red nozzle) 0.07 to 0.18 mL of liquid per minute are nebulized. Depending on compressor flow, 74-80.6% thereof is <5 μm in size and 26-34% is <2 μm in size. The aerosol rates are determined according to ISO 27427:2013 with salbutamol.

[0176] The nebulizer of the aerosol generator is filled with 6 mL of 0.9% NaCl solution for each test. The nebulizer is operated without mouthpiece at 20° C. test temperature and a volume flow of 3 L/min (measured by water displacement from volumetric flask according to device).

[0177] The aerosol stream is fed directly into a tube with a diameter the size of the nebulizer opening (outer diameter d.sub.a=20 mm, inner diameter d.sub.i=18 mm, length l=200 mm). The tube is configured to hold the ion exchanger. In each case 10 g of ion exchanger are filled in and fixed with a 3 mm thick layer of cotton wadding. As an alternative to cotton wadding, 20 mm filter foam with 30 ppi (pores per inch, which corresponds to 30 pores per 25.4 mm) made of polyurethane can be used (filter tube).

[0178] At least 2, typically 3 to 4 collection bottles are arranged downstream of this tube. These are each 100, 250, 500 or 1000 mL capacity, top-sealed polypropylene wide-neck bottles, which are provided with two connections made of stainless steel tube (outer diameter d.sub.a=6 mm) at the sides. The inlet connection protrudes to the bottom of the bottle and is slit at the bottom 4 times 5 mm upwards to create turbulence. The outlet connection is short and is used for gas discharge. The advantage of this arrangement is that it is compact and has no sharp-edged parts. In addition, it can be assembled and disassembled without tools. All parts can be disinfected in a bath and are autoclavable.

[0179] To carry out the experiment, the first collecting bottle (250 ml) after the sample tube is filled with 150 mL of demineralised water in which a conductivity electrode is completely immersed. Two more empty bottles are placed after the collection bottle to collect liquid droplets carried along by the air flow. During the experiment, the air flow is measured downstream of the system and, after the experiment, the liquid residues are removed from the evaporator and weighed back.

[0180] In the course of the experiment, the conductivity in the first collection bottle is recorded against time for an experimental period of 30 minutes. The conductivity follows the NaCl concentration in a linear fashion and is 64 mS.Math.L.Math.mol.sup.−1 at 25° C. The 0.9 wt % NaCl solution used has a conductivity of 13.66 mS cm.sup.−1 at room temperature (20±3° C.). The increase in conductivity is determined by linear extrapolation. The retention in % is calculated as (1−(slope sample/slope empty tube))*100.

[0181] The following ion exchangers are used:

[0182] (1) Purolite® MB 400, a polystyrene-based mixed bed resin composed of a strongly basic type I anion exchanger with quaternary ammonium ions in the hydroxide form and a strongly acidic gel cation exchanger with sulfonic acid groups in the hydrogen form. The capacity of the exchanger is about 1.9 eq/L. They are spherical balls of a gel of 300 to 1200 μm in size, a water content of 65% and a bulk density of 705-740 g/L.

[0183] (2) Amberlite® IRC 120, a strongly acidic cation exchanger in the H.sup.+ form. It is a gel ion exchanger based on styrene-divinylbenzene with a water content of 50%. The exchanger capacity is 1.8 eq/L. The bulk density is 785 g/L. The particle size of the exchanger is 95% between 300 and 1200 μm.

[0184] A Hygostar type IIR/PP>98% BFE medical mask is used as a reference (positive control). The test section corresponds to the inner diameter of the tube.

[0185] As a negative control (empty tube), the tube is filled with cotton wool.

[0186] Results are reported relative to retention in the negative control and are summarized in Table 1.

TABLE-US-00001 TABLE 1 Retention of aerosols NaCl permeation/μS Relative Sample name cm.sup.−1 min.sup.−1 retention/% Negative control (cotton wool) 8.764 0 (1) Purolite MB 400 0.485 94.5 (2) Amberlite IRC 120 0.194 97.8 Positive control (Hygostar) 0.016 99.8

[0187] All backweighing results show that more than 4 g of NaCl solution was atomized during the test duration. It could thus be shown that the ion exchangers according to the invention can retain more than 90% of airborne aerosols from a volume flow.

Example 2. Preparation of H.SUP.+ and Metal Ion Loaded Ion Exchangers

[0188] For the following tests, the strongly acidic cation exchange resin Amberlite® IRC 120 Na with a sodium content of 9.2% based on the dry mass of the exchanger is used. This is a gel based on sulfonated polystyrene in the Na form, crosslinked with divinylbenzene. The exchange capacity is >2 eq/L, the water content is 49% and the density is 840 g/L. The resin contains <2% of particles <300 μm and <4% of particles >1180 μm.

[0189] To prepare the H.sup.+ form, the cation exchange resin is packed into a column. Glass columns with an inner diameter of 20 mm and a length of 200 mm (up to 20 g filling) and a column with an inner diameter of 40 mm and a length of 1000 mm (for Cu(1)) are used. The columns have filter plates with porosity 0 (ISO P 250, nominal width of pores 160-250 μm). It is rinsed with hydrochloric acid of pH 0. 100 mL of 1N hydrochloric acid (0.1 mol) to 10 g resin (0.024 mol) is used (excess) to ensure as complete a conversion as possible to the H.sup.+ form. The exchanger is then rinsed with deionized water until the eluate is no longer acidic and has a conductivity <20 μScm.sup.−1. The loaded resin is removed and designated as H-(1). It has a water content of 51%.

[0190] To prepare a metal ion-loaded ion exchanger, the ion exchange resin in the H.sup.+ form thus obtained is packed into a column and rinsed with a solution of an appropriate metal salt. The flush rate is one bed volume per hour. Flush rates up to 50 bed volumes per hour are possible, but result in lower loadings. The exchanger is then rinsed with deionized water until the eluate has a conductivity <20 μScm.sup.−1. The loaded resin is removed.

[0191] In the Ti-(1) variant, the initially turbid solution is left to stand overnight on the ion exchanger. As a result of the release of H.sup.+ ions, the turbidity disappears, as a sulfuric acid solution is formed. The calculation of the degree of loading by the respective metal is based on an ion exchange capacity IEC (Ion Exchange Capacity) of 4 meq/g for Na.sup.+ with respect to the dry mass of the ion exchanger (2 meq/g with respect to moist ion exchanger). This is a comparative observation, since the exchanger capacity refers to Na.sup.+ ions and was not determined for the respective ions. It can be assumed that not all exchanger sites accessible for sodium are accessible for the larger metal ions and that loading of the geometrically inner sites takes place kinetically delayed.

[0192] The resins obtained and the corresponding loadings are listed in Table 2.

TABLE-US-00002 TABLE 2 Cation exchange resins obtained from Amberlite ® IRC 120 Na. Ion/metal content in [wt.-%].sup.1 Educt H-(1) Metal salt Metal salt (loading Sample [g].sup.1 used [g/ml water] degree metal) Zn-(1) 11.7 Zinc(II) acetate 10.55/100  Zn.sup.II/19.5 dihydrate (75 mol %) Cu-(1) 340.3 Copper(II) 350.0/2000 Cu.sup.II/18.2 sulfate (72 mol %) hexahydrate Ag-(1) 9.9 Silver(I) 8.04/100 Ag.sup.I/34.1 nitrate (79 mol %) Fe-(1) 11.2 ferric chloride .sup. 13/100 Fe.sup.III/21.5 hexahydrate (96 mol %) Ti-(1) 20 Ti(IV)O 7.61/150 Ti.sup.IV/7.5 sulfate (39 mol %) Sn-(1) 20 Tin(II) 10.27/100  Sn.sup.II/25.4 sulfate (53 mol %) .sup.1based on the dry mass of the ion exchanger.
The percentage loading is highest at 96 mol-% for Fe.sup.3+. The respective percentage difference is present in the H.sup.+ form (e.g. 4 mol-% for Fe.sup.3+).

Example 3: Antiviral Activity of Ion Exchangers

[0193] In addition to aerosol retention, it is central to the operation of the invention that retained pathogens are sorbed and inactivated at the ion exchangers.

The antiviral activity of the metal-loaded ion exchangers as well as the acidic ion exchanger H-(1) can be investigated in suspension experiments, for example as described as follows: Human coronavirus HCoV-OC43Rluc is used as the virus. Virus concentrate is incubated for 30 min with the ion exchangers prepared in Example 2 (100 mg/mL) at room temperature in a shaker. The polymer is then removed by centrifugation, the supernatant is removed and titrated onto 293 T cells. Cells are lysed 30 h after inoculation and Renilla assays are performed on the lysates. The reduction of viral activity is calculated from the Renilla signal of the reporters in RLU (relative light units) compared to the reference at a dilution of the supernatant of 1:10. It can be shown that the cation exchanger H-(1) in the H.sup.+ form as well as Ti-(1) and Sn-(1) are most effective. The very effective form Ti-(1) is only partially converted and is about 60% in the H.sup.+ form. Cu-(1) as well as Ag-(1) cation exchangers can also be very effective.

Example 4: Antibacterial Activity of Ion Exchangers

[0194] The antibacterial activity of the ion exchangers can be studied in suspension experiments, for example as described as follows: The following bacterial strains are used: Streptococcus pneumoniae, Haemophilus influenzae and Staphylococcus aureus, methicillin resistant. Mix each 100 mg of ion exchanger with 1 mL of a PBS buffer solution and one bacterial colony taken directly from an agar plate. Then incubate for 2, 10 and 30 min at 37° C. on the shaker. Cu-(1) is used as ion exchanger. S. aureus, methicillin resistant (Gram positive) can be successfully killed after 2 min incubation, no growth is seen after 72 h. For Streptococcus pneumoniae and Haemophilus influenzae, delayed growth can be observed after 10 and 30 min of incubation. In the light microscope, bacteria can be found on the ion exchanger surface.

Example 5: Determination of Characteristic Curves for the Design of Ventilation Systems

[0195] To determine ventilation characteristics, packings of ion exchangers are installed in pipes and the pressure drop is measured as a function of the flow velocity. H-(1) is used as an example of a strongly acidic cation exchanger. The water content is 50%, 95% of the particles are between 0.3 and 1.2 mm in size. An adjustable duct fan is used with a fan speed of up to 3800 rpm and a free-flowing air stream (manufacturers specification) of up to 561 m.sup.3/h to 565 Pa.

[0196] The suction takes place free-flowing via a pipe (diameter 125 mm, length 50 cm). The ion exchanger packing is installed on the pressure side in a pipe with an inner diameter of 11.25 cm. The packing is held between two discs of open-pored filter foam (polyester-based polyurethane foam) with 20 mm thickness and with a pore size of 30 ppi, as they are used as pre-filters in air-conditioning systems.

[0197] The pressure difference along the packing and the volume flows are determined with a differential pressure gauge and pitot tube anemometer Trotec TA 400. For this purpose, measuring connections are installed in the flow pipe upstream and downstream of the ion exchanger packing. For linearization, the flow after the packing is guided through a constricted cylindrical pipe with a diameter of 64 mm.

[0198] The pressure drop is determined as a function of the flow velocity at 20.7° C. with air. With the fan at maximum power, air velocities of maximum 13.5 m/s result during free blowing in the device, which corresponds to 483 m.sup.3/h.

TABLE-US-00003 TABLE 3 Pressure drop vs. flow velocity for prefilter made of 2 layers of filter foam, each with 2 cm thickness and 30 ppi Velocity [m/s] Pressure drop/Pa in 11.25 cm (d) tube Volume flow m.sup.3/h 281 4.23 151 226 3.9 140 155 3.25 116 65 2.34 84 28 0.93 33

TABLE-US-00004 TABLE 4 Pressure drop vs. flow velocity for packing thickness of 1 cm ion exchanger H-(1) (100 g) between two layers of filter foam, each with 2 cm thickness and 30 ppi Velocity [m/s] Pressure drop/Pa in 6.4 cm (d) tube Volume flow m.sup.3/h 336 5.61 65 209 4.72 55 92 2.36 27 41 0.2 2

[0199] These data show that packings of commercially available ion exchange resins can be used in conventional ventilation systems with moderate pressure losses at high volume flow rates.

Example 6: Antiviral Efficacy Against SARS-CoV-2 Viruses

[0200] The studies are performed with Human 2019-nCoV strain 2019-nCoV/Italy-INMI1, clade V, sequence see GenBank (SARS-CoV-2/INM11 isolates/2020/Italy: MT066156).

[0201] The antiviral efficacy of H-(1) is studied by the following method: Virus (in DMEM, Dulbecco's Modified Eagle's Medium, high glucose, Thermo Fisher 41965) with a titer of (>10.sup.6 TCID.sub.50/ml) is used (TCID=tissue culture infectious dose, the dose necessary to induce infection in 50% of the cell cultures). The virus suspension is incubated with ion exchanger H-(1) (10 wt %) under shaking. The virus titer of SARS-CoV-2 is measured in the upper phase after separation from ion exchanger H-(1). Samples are taken 2, 10 and 30 minutes after addition of the ion exchanger. A 10-fold dilution series (10.sup.−1 to 10.sup.−6) of supernatants is used to infect a Vero E6 cell monolayer in a 96-well plate. Cells are cultured for 72 hours and infection is quantified microscopically by cytopathic effect (Leica microscope). The virus titer is determined by the Reed-Muench method. A virus suspension without the addition of an ion exchanger is used as a control. The results are given in Tables 5 to 11.

[0202] Bound viruses of the 30 min incubated sample are eluted from H-(1) with 0.9 wt % NaCl solution. The eluate is diluted (minimum 1:10 final in complete culture medium) and tested for replication ability in Vero E6 cells. NaCl 0.9 wt % and the virus in NaCl 0.9 wt % are tested at the same dilution as a control.

[0203] The virus titer is determined in Vero E6 cells (Cercopithecus aethiops, kidney, ATCC CRL-1586). The cell line is routinely maintained in DNEM culture medium with the addition of 1% glutamine, 1% penicillin/streptomycin and 10% FBS (fetal bovine serum).

[0204] Viral replication capacity is determined as follows: Exponentially growing Vero E6 cells are seeded into a 96-well plate at optimal density in complete medium. 24 h later, cells are exposed to eluates of ion exchanger H-(1) and controls. Another control is cells infected with SARS-CoV-2 (multiple of infection, 0.01 TCID.sub.50/cell). The cells are then cultured for 72 h. Two replicates for each concentration are examined. At the end of the incubation period, the antiviral activity is quantified on the one hand by an ELISA assay (Enzyme-linked Immunosorbent Assay (ELISA), an antibody-based detection method (assay)) (Sino Biological, quantifying SARS-CoV-2 nucleoprotein) and on the other hand by microscopic control of cytopathic effect (Images: Leica Microscope). The results are shown in Table 12.

[0205] The following tables 5 to 10 show the readout of the experiment to determine the virus titer after 72 hours. Incubation with Vero E6 cells. Infected (+) and uninfected (−) wells are indicated for the 6 replicates of 10-fold serial dilutions tested for each supernatant collected. The infection status of each well was assessed by observing the cytopathic effect on the microscope. Score: infected “+”, not infected “−”, First row each dilution of supernatant.

TABLE-US-00005 TABLE 5 2-minute incubation time. Control suspension virus (not treated with H-(1)) 10.sup.−1 10.sup.−2 10.sup.−3 10.sup.−4 10.sup.−5 10.sup.−6 10.sup.−7 10.sup.−8 10.sup.−9 + + + + + − − − − + + + + − − − − − + + + + − − − − − + + + + − − − − − + + + + − − − − − + + + + − − − − −

TABLE-US-00006 TABLE 6 2-minute incubation time. Virus suspension treated with 10 wt % H-(1) 10.sup.−1 10.sup.−2 10.sup.−3 10.sup.−4 10.sup.−5 10.sup.−6 10.sup.−7 10.sup.−8 10.sup.−9 + + − − − − − − − + + − − − − − − − + + − − − − − − − + + − − − − − − − + + − − − − − − − + + − − − − − − −

TABLE-US-00007 TABLE 7 10-minute incubation time. Control suspension virus (not treated with H-(1)) 10.sup.−1 10.sup.−2 10.sup.−3 10.sup.−4 10.sup.−5 10.sup.−6 10.sup.−7 10.sup.−8 10.sup.−9 + + + + − − − − − + + + + − − − − − + + + + − − − − − + + + + − − − − − + + + + + − − − − + + + + − − − − −

TABLE-US-00008 TABLE 8 10-minute incubation time. Virus suspension treated with 10 wt % H-(1) 10.sup.−1 10.sup.−2 10.sup.−3 10.sup.−4 10.sup.−5 10.sup.−6 10.sup.−7 10.sup.−8 10.sup.−9 − − − − − − − − − + − − − − − − − − − + − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − −

TABLE-US-00009 TABLE 9 30-minute incubation time. Control suspension virus (not treated with H-(1)) 10.sup.−1 10.sup.−2 10.sup.−3 10.sup.−4 10.sup.−5 10.sup.−6 10.sup.−7 10.sup.−8 10.sup.−9 + + + + + − − − − + + + + + − − − − + + + + − − − − − + + + + − + − − − + + + + + − − − − + + + + + − − − −

TABLE-US-00010 TABLE 10 30-minute incubation time. Virus suspension treated with 10 wt % H-(1) 10.sup.−1 10.sup.−2 10.sup.−3 10.sup.−4 10.sup.−5 10.sup.−6 10.sup.−7 10.sup.−8 10.sup.−9 − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − −

TABLE-US-00011 TABLE 11 Virus titer calculated by Reed-Muench method for the different test conditions for samples incubated with 10 wt % H-(1) and control samples without treatment. Log reduction compared to Test condition Virus titer control 2 min incubation, control 3.98E+05 2.1 2 min incubation, H-(1) 3.16E+03 10 min incubation, control 3.98E+05 >3.6 10 min incubation, H-(1) <1.00E+02  30 min incubation, control 2.29E+06 >4.36 30 min incubation, H-(1) <1.00E+02 

[0206] The following Table 12 shows antiviral activity data of test samples from the virus replication capacity determination experiment. Mean and standard deviation values of SARS-CoV-2 nucleoprotein are shown for each test condition.

TABLE-US-00012 TABLE 12 Antiviral activity (SARS-CoV-2 nucleoprotein, ELISA). M.o.i. (multiplicity of infection) means the number of TCID.sub.50 (infectious dose of tissue cells 50%, i.e. the amount of virus infecting half of the culture cells)/cells used for infection. SARS-CoV-2 nucleoprotein in ng/mL Test condition Mean value Standard deviation Control (0.01 m.o.i) 1125 202 Virus + NaCl 0.9% >50 — NaCl 0.9% (negative control) <0.07 — Eluted fraction of H-(1) 4.07 0.29 30 min Virus incubation

[0207] The eluted fraction comprises hardly any detectable viral nucleoprotein, indicating almost complete inactivation of the virus.

Example 7. Impactor Test Room Air with Microscopic Evaluation

[0208] Filter tubes according to Example 1 are tested in impactor tests for the retention of particles from room air. A particle collector PS 30 from Holbach Umweltanalytik and adhesively coated slides are used for this purpose. Sampling is carried out by means of a diaphragm pump, which is regulated to a volume flow of 5 litres per minute by means of a dosing valve. A sample is taken for 30 min, which corresponds to a total volume of 150 L. The samples are examined using a light microscope (Leica, at magnification 200-1000) and particles are identified as far as possible. Comparatively, the following results were obtained (Table 13):

TABLE-US-00013 TABLE 13 Results of impactor test. sampling location Without ion exchanger With ion exchanger H-(1) Outdoor Air, Grass pollen, various Sporadically, Meadow, May Rye Pollen not identifiable Fungal spores Fiber residues Indoor air, Fiber residues Sporadically, bedroom Mites not identifiable Sporadically spores Dust, miscellaneous

[0209] The results show that packings of ion exchange resins also retain various particles with sizes of several μm and pollen.

Example 8. Retention of DNA from Aerosol by Ion Exchanger

[0210] 0.1 g deoxyribonucleic acid, low molecular weight, from salmon sperm (CAS number 1000403-24-5, Sigma Aldrich 31149) sheared to ≤2000 bp (base pairs) is suspended in 5 ml distilled water in a tube shaker at room temperature for 10 min.

[0211] The suspension is nebulized as an aerosol in a device as described in example 1 immediately after shaking. After the filter tube, 2 bottles each containing 100 ml of distilled water are arranged to collect the DNA. The amount of DNA transferred is determined gravimetrically as dry residue. Determined is the retention compared to the blank tube in %, calculated as (dry residue sample-zero sample)/(dry residue blank tube+filter foam 2×2 cm 30 psi zero sample). 10 g of ion exchanger is used in each case.

[0212] Preparation of anion exchanger on glass beads (A-glass-(1)): 1.0518 g PVA (Polinol 1000) is dissolved at 60° C. in 50 ml water. After cooling, 1.3 g of 37% HCl is added. 0.7218 g diethylaminoacetaldehyde dimethyl acetal is added and kept at 60° C. for 1 h. Then 0.5315 g of butyraldehyde dimethyl acetal is added under stirring. After about 5 min, a white, spherical polymer precipitates. This is washed with water until the supernatant no longer reacts acidically, and dried. 1.165 g of dried product is obtained. The product is suspended or dissolved in 20 ml ethanol at 40° C. and mixed with 10 g glass spheres (3M® Glass Bubbles K 1.65 μm). Ethanol is evaporated under stirring and the resulting mass is ground in a mortar.

[0213] Preparation of anion exchanger with diethylaminoethanol function (DEAE-1): An ion exchange resin is prepared according to JPS5811046 A, but in deviation from the protocol, diethylaminoethanol is used instead of morpholine.

[0214] DEAE-Sepharose® CL-4B (DEAE-2) with the functional group —OCH.sub.2CH.sub.2N.sup.+H(CH.sub.2CH.sub.3).sub.2 and chloride as counterion with an ion exchange capacity of 0.13-0.17 meq/mL is flushed from a suspension of 20% ethanol with 0.5 molar sodium chloride solution into the empty tube with filter foam and the liquid is allowed to drain. DEAE-2 is composed of particles from 45 to 165 μm in size.

[0215] Purolite® MB 400 is used as a mixture of cation and anion exchangers, consisting of a strongly basic type I anion exchanger with quaternary ammonium ions in the hydroxide form and a strongly acidic gel cation exchanger with sulfonic acid groups in the hydrogen form (abbreviated: HOH-(1)).

[0216] As a negative control, 200 ml of demineralised water as used is dried. The dry residue of 0.5 g obtained corresponds to the detection limit of the method. A pipe with 2×2 cm filter foam 30 ppi (pores per inch, which corresponds to 30 pores per 25.4 mm) made of polyurethane is used as the blank pipe. The results are summarized in Table 14.

TABLE-US-00014 TABLE 14 Results DNA retention. Sample name Dry residue/mg Relative retention/% Empty pipe with filter foam 45   0% H-(1) 0.8 99 A-glass-(1) 1.5 98 HOH-(1) 1.2 98 DEAE-(1) 0.8 99 DEAE-(2) 0.7 100 

[0217] The ion exchangers all show a very high retention for DNA in aerosol form.

Example 9: Retention of Aerosols with Glycerinated Ion Exchanger

[0218] 20 g of an ion exchanger H-(1) are mixed with 5 g of glycerol (>99% purity) and dried at 110° C. until constant weight. The obtained ion exchanger H-(2) is filled into a filter tube as described in Example 1 and closed on both sides with filter foam of a thickness of 2 cm, porosity 30 ppi (pores per inch, corresponding to 30 pores per 25.4 mm). An aerosol stream is added by means of a 5 wt.-% NaCl solution at 20° C. and a volume flow of 1.5 cm/s (corresponding to 230 ml/min). The aerosol is generated with a Palas® PLG1000 aerosol generator, and the penetrating aerosols are detected fractionally by size with a Palas® Promo 1000 aerosol spectrometer. Depending on the aerosol size, the following retention rates result (Table 15):

TABLE-US-00015 TABLE 15 Results NaCl aerosol retention with H-(2). Aerosol size/nm Relative retention/% 100 80 150 90 1000 99

[0219] Retention increases with increasing size of aerosol particles.

Example 10 Further Possible Uses

[0220] 6.1) The cation exchange resin H-(1) is filled into a cylindrical piece of tubing, which is closed on both sides with a filter fabric. The tube is connected to a conventional reusable breathing mask by means of a flexible corrugated tube.

[0221] 6.2) A cation exchange resin according to example 6.1 is sealed in a bag made of a porous material, such as Tyvek™ or Gore-Tex™ of dimension 10*10 cm. A filter fleece is inserted into the bag to spatially fix the resin. The bag is inserted between two layers of a filtering mouth protection. A special bag may be provided for insertion so that separation/cleaning can be performed. Alternatively, the bag may be fixed in its position by a holding device, adhesive tape, sewing or gluing.

[0222] 6.3) A device such as examples 6.1 and 6.2, in admixture with ion exchange resins, using ions of the following elements or mixtures thereof: Ti, V, Cr, Mo, W, Mn, Fe, Ru, Co, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg, Pb, Ge, Ce, Sn, Al, or a lanthanide.

[0223] 6.4) A device according to examples 6.1-6.3, in which a mixed ion exchanger is used and borates are used as anion.

[0224] 6.5) A device according to examples 6.1-6.4, in which a mixed ion exchanger is used and NH.sub.4.sup.+ is also used as cation.

[0225] 6.6) Use of a device according to example 6.1-6.5 for the reduction of bacteria and viruses from a respiratory air stream. The retention of bacteria and viruses is assessed according to EN 14126, analogous to ISO 16603 and ISO 22610.

[0226] 6.7) Use of a device according to examples 6.1-6.5 for the retention of corona viruses.

[0227] 6.8) Use of a device according to examples 6.1-6.5 for the retention of SARS-CoV 2.

[0228] 6.9) Use of a device according to example 6.1-6.5 to reduce the bacteria and virus count in distilled water by flowing the water through the device.

[0229] 6.10) Use of a device according to example 6.1-6.8 as a filtering device upstream of air volumes such as shelters, car interiors, air conditioning systems, cabins, airplanes, emergency vehicles, truck cabs, vehicles of security forces, respiratory equipment, intensive care units, staff rooms, rooms for animal husbandry or other rooms in which people, animals or plants are present or located.

[0230] 6.11) Protection of air or liquid carrying devices against germination or biological contamination by devices according to example 6.1-6.8.

[0231] 6.12) Ventilation valve according to example 6.1-6.8.

[0232] 6.13) An anion exchanger is used which is obtained by functionalizing a scaffold polymer containing halogen end groups with diethylaminoethanol. The anion exchanger may be used partially or substantially completely in the hydroxide form.

[0233] 6.14) Advantageous are also anion exchangers functionalized with sterically hindered amines, so that an increased base stability of the exchangers results and the exchangers also remain thermally stable in OH form or can be sterilized. An example of such amine is DABCO, diazabicyclooctane.

[0234] 15) A ceiling fan is equipped with blades filled with ion exchange resin.

[0235] 16) A flow-through molded body filled with ion exchange resin is arranged on a rotating device and air flow is generated due to rotation. This device may be combined with a humidifying device.

[0236] Described below are further embodiments of the present invention.

[0237] According to embodiment 1, the present invention relates to the use of one or more ion exchangers for the reduction and/or removal of biological contaminants in gases and/or gas streams.

[0238] According to embodiment 2, the use according to embodiment 1 is characterized in that the biological contaminants are selected from the group consisting of viruses, bacteria, molds, fungal spores, mites, mite residues, mite droppings, pollen as well as fragments of the foregoing, metabolic products, such as mycotoxins, proteins, RNA and DNA, are preferably selected from the group consisting of enveloped viruses, non-enveloped viruses, bacteria, fungal spores and proteins and particularly preferably selected from the group consisting of coronaviruses, SARS-type viruses, SARS-CoV-2 viruses, resistant pathogens and multiresistant pathogens. Particularly preferred is the use of one or more ion exchangers for the reduction and/or removal of coronaviruses in gases and/or gas streams.

[0239] According to a further embodiment, the use according to any one of the preceding embodiments is characterized in that the ion exchanger comprises at least one cation exchanger, optionally the cation exchanger being at least one of a weakly acidic cation exchanger, a strongly acidic cation exchanger, or a mixture thereof.

[0240] According to a further embodiment, the use according to any one of the preceding embodiments is characterized in that the strongly acidic cation exchanger is an organic, particularly preferably a synthetic resin ion exchanger, having sulfonic acid and/or sulfonate groups, preferably selected from a cross-linked polystyrene sulfonate or cross-linked poly(2-acrylamido-2-methyl propanesulfonic acid) (polyAMPS).

[0241] According to a further embodiment, the use according to any one of the preceding embodiments is characterized in that the cation exchanger is partially or substantially completely loaded with H.sup.+ ions.

[0242] According to a further embodiment, the use according to any one of the preceding embodiments is characterized in that the ion exchanger is selected from the group consisting of anion exchangers, mixed anion and cation exchangers, cation exchangers loaded with transition metal ions, ion exchangers bearing chelate ligands, mixtures thereof and mixtures thereof with cation exchangers, wherein preferably the anion exchanger is partially or substantially completely loaded with OH.sup.− ions.

[0243] According to a further embodiment, the use according to any one of the preceding embodiments is characterized in that the ion exchanger is at least one cation exchanger loaded with transition metal ions, wherein the transition metal ions are selected from the group consisting of cations of Ti, V, Cr, Mo, W, Mn, Fe, Ru, Co, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg, Pb, Ge, Sn, Al, or a lanthanide, and mixtures thereof, and preferably selected from the group consisting of cations of copper, silver, titanium, and mixtures thereof.

[0244] According to a further embodiment, the use according to any one of the preceding embodiments is characterized in that the ion exchanger is present in solid form, preferably as an organic ion exchanger and particularly preferably as a synthetic resin ion exchanger, wherein the ion exchanger may be present in particulate form, as a flow-through fill and/or as an insert in a mouth-nose protection. The ion exchanger in solid form is preferably insoluble in water.

[0245] According to a further embodiment, the use according to any one of the preceding embodiments is characterized in that the ion exchanger further comprises hygroscopic auxiliary agents and/or hygroscopic functional groups, or is used in combinations with such auxiliary agents.

[0246] According to a further embodiment, the use according to any one of the preceding embodiments is characterized in that the gases and/or gas streams are air and/or air streams, preferably selected from the group consisting of room air, room air streams and breathing air streams, wherein the room air and room air streams are preferably selected from room air and room air streams in shelters, motor vehicle interiors, air-conditioned rooms, cabins, airplanes, emergency vehicles, truck cabs, vehicles of security forces, respiratory equipment, intensive care units, staff rooms, rooms for animal husbandry and other rooms in which humans, animals or plants are present or located.

[0247] According to a further embodiment, the use according to any one of the preceding embodiments is characterized in that the ion exchanger is designed as a filling of a hollow body and/or as a porous molded body, the hollow body and/or the molded body preferably being inserted or incorporated into or being connected to a respiratory mask.

[0248] According to a further embodiment, the use according to any one of the preceding embodiments is in combination with one or more of the methods selected from the group consisting of filtration, humidification, drying, condensation, UV treatment, corona or plasma treatment, high voltage treatment, radioactive radiation treatment, treatment by heating and treatment by cooling.

[0249] According to a further embodiment or aspect, the present invention relates to a method for removing and/or reducing biological contaminants in gases and gas streams by means of one or more ion exchangers, characterized in that the gases or gas streams are brought into contact with an ion exchanger.

[0250] According to a further embodiment, the method according to any one of the preceding embodiments is characterized in that the biological contaminants are selected from the group consisting of viruses, bacteria, molds, fungal spores, mites, mite residues, mite droppings, pollen and fragments of the foregoing, metabolic products, such as mycotoxins, proteins, RNA and DNA, are preferably selected from the group consisting of enveloped viruses, non-enveloped viruses, bacteria, fungal spores and proteins and particularly preferably selected from the group consisting of coronaviruses, SARS-type viruses, SARS-CoV-2 viruses, resistant pathogens and multi-resistant pathogens. Particularly preferably, the method is employed using one or more ion exchangers for the reduction and/or removal of coronaviruses in gases and/or gas streams.

[0251] According to a further embodiment, the method according to any one of the preceding embodiments is characterized in that the ion exchanger comprises at least one cation exchanger, optionally the cation exchanger being at least one of a weakly acidic cation exchanger, a strongly acidic cation exchanger, or a mixture thereof.

[0252] According to a preferred embodiment, the method according to any of the preceding embodiments is characterized in that the strongly acidic cation exchanger is an organic, particularly preferably a synthetic resin ion exchanger, having sulfonic acid and/or sulfonate groups, preferably selected from a cross-linked polystyrene sulfonate or cross-linked poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (polyAMPS).

[0253] According to a further embodiment, the method according to any one of the preceding embodiments is characterized in that the cation exchanger is partially or substantially completely loaded with H.sup.+ ions.

[0254] According to a further embodiment, the method according to any one of the preceding embodiments is characterized in that the ion exchanger is selected from the group consisting of anion exchangers, mixed anion and cation exchangers, cation exchangers loaded with transition metal ions, ion exchangers bearing chelate ligands, mixtures thereof and mixtures thereof with cation exchangers, wherein preferably the anion exchanger is partially or substantially completely loaded with OH.sup.− ions.

[0255] According to a further embodiment, the method according to any one of the preceding embodiments is characterized in that the ion exchanger is at least one cation exchanger loaded with transition metal ions, wherein the transition metal ions are selected from the group consisting of cations of Ti, V, Cr, Mo, W, Mn, Fe, Ru, Co, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg, Pb, Ge, Sn, Al, or a lanthanide, and mixtures thereof, and preferably selected from the group consisting of cations of copper, silver, titanium, and mixtures thereof.

[0256] According to a further embodiment, the method according to any one of the preceding embodiments is characterized in that the ion exchanger is present in solid form, preferably as an organic ion exchanger and particularly preferably as a synthetic resin ion exchanger, wherein the ion exchanger may be present in particulate form, as a flow-through fill and/or as an insert in a mouth-nose protection.

[0257] According to a further embodiment, the method according to any one of the preceding embodiments is characterized in that the ion exchanger further comprises hygroscopic auxiliary agents and/or hygroscopic functional groups, or is used in combinations with such auxiliary agents.

[0258] According to a further embodiment, the method according to any one of the preceding embodiments is characterized in that the gases and/or gas streams are air and/or air streams, preferably selected from the group consisting of room air, room air streams and breathing air streams, wherein the room air and room air streams are preferably selected from room air and room air streams in shelters, motor vehicle interiors, air-conditioned rooms, cabins, airplanes, emergency vehicles, truck cabs, vehicles of security forces, respiratory equipment, intensive care units, staff rooms, rooms for animal husbandry and other rooms in which humans, animals or plants are present or are located.

[0259] According to a further embodiment, the method according to one of the preceding embodiments is characterized in that the ion exchanger is designed as a filling of a hollow body and/or as a porous molded body, the hollow body and/or the molded body preferably being inserted or incorporated into or being connected to a respiratory mask.

[0260] According to a further embodiment, the method according to any one of the preceding embodiments is carried out in combination with one or more of the methods selected from the group consisting of filtration, humidification, drying, condensation, UV treatment, corona or plasma treatment, high voltage treatment, radioactive radiation treatment, treatment by heating and treatment by cooling.