Application of an electrode material with intracellular resistance gene slashed in drug-resistant bacteria

Abstract

This invention discloses the application of an electrode material for reducing intracellular resistance genes in drug-resistant bacteria. A platinum-doped dendritic TiO2 nanowire structure based on a three-dimensional material is formed by growing a micron-sized TiO2 backbone array and platinum-doped nano-sized TiO2 branches on the surface of a porous electrode. The prepared dendritic nanowire three-dimensional electrode material has a larger specific surface area, providing more reactive sites and strong electric field sites. Platinum doping enhances the conductivity and electrocatalytic performance of the nanowires. Furthermore, by combining it with chloride salts / oxidants, the electroporation and electrocatalysis of the nanowire electrode surface are coupled. The strong electric field confined at the nanowire tip induces perforation of the drug-resistant bacterial cell structure, strengthening the contact and reaction between the oxidant and the resistance gene. The high electrocatalytic activity confined at the nanowire tip induces the generation of strong oxidizing free radicals, achieving the goal of destroying the drug-resistant bacterial cell structure and efficiently reducing intracellular resistance genes.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to the application of an electrode material with reduced intracellular resistance genes in drug-resistant bacteria. Background Technology

[0002] Antibiotic resistance caused by drug-resistant bacteria (ARBs) and their resistance genes (ARGs) is one of the major challenges facing global public health.

[0003] Drinking water is one of the important routes of drug resistance transmission, and disinfection is a key link in drinking water treatment processes to kill microorganisms and prevent the spread of infectious diseases.

[0004] Due to the barrier protection and oxidative competition of bacterial EPS / wall / membrane / matter, conventional drinking water disinfection processes such as chlorine, ozone, and ultraviolet light cannot effectively reduce intracellular i-ARGs. Problems such as a wide variety and high abundance of ARGs have been found in drinking water effluents, pipe networks, and tap water for users around the world. How to efficiently reduce intracellular i-ARGs of ARBs has become an important issue of concern in the field of drinking water disinfection.

[0005] Novel nanowire electrochemical technology can utilize the lightning rod effect of nanowires to form a confined strong electric field and a highly electrocatalytically active region at the tip. By coupling the electroporation and electrochemical oxidation of nanowires, it can effectively disrupt the ARB cell barrier structure, thereby potentially improving the reduction efficiency of oxidative substances on i-ARGs.

[0006] However, without the addition of oxidants or electrolytes, the single nanowire electrochemical technology can only generate limited oxidizing substances and cannot effectively reduce intracellular i-ARGs in ARBs in drinking water.

[0007] To this end, this invention proposes a synergistic oxidation strategy combining nanowire electrochemistry with chloride / sulfate / oxidant, which disrupts ARB cell structure and enhances intracellular i-ARG reduction through the following synergistic effects:

[0008] 1) Barrier penetration effect: The strong electric field confined at the tip of the nanowire can induce perforation of EPS / wall / membrane in ARB cells, providing channels for oxidants to penetrate into the cell and i-ARGs to leak out of the cell, thus enhancing the contact and reaction between oxidants and ARGs.

[0009] 2) Enhanced oxidation: The high electrocatalytic activity confined at the tip of the nanowire can promote the generation of sulfate radicals such as SO4-·, RCS radicals such as Cl• and Cl2•−, or ROS radicals such as O2•− and •OH from sulfates, chlorides, or oxidants, thereby enhancing the oxidation reduction effect of i-ARGs.

[0010] Titanium dioxide (TiO2), as a semiconductor material, has good conductivity and a tunable nanowire structure, and can be used for electrode modification.

[0011] However, the prepared electrodes still exhibit insufficient reaction sites or excessive resistance, failing to adequately provide reactive sites and strong electric field sites to achieve confined strong electric field destruction of ARB cell structure, electrocatalysis of strong oxidizing free radical generation, and reduction of intracellular i-ARGs. Summary of the Invention

[0012] In order to overcome the above-mentioned shortcomings and deficiencies of the prior art, the present invention aims to provide a dendritic nanowire electrode material for the reduction of intracellular resistance genes of drug-resistant bacteria in drinking water and its preparation method. The prepared dendritic TiO2 nanowire three-dimensional electrode material has a larger specific surface area, can provide more reactive sites and strong electric field sites, and further utilizes platinum doping to improve the conductivity and electrocatalytic performance of the nanowires.

[0013] To achieve the above objectives, the present invention provides the following technical solution: The application of an electrode material for reducing intracellular resistance genes in drug-resistant bacteria, comprising micron-scale TiO2 backbone array growth and platinum-doped nano-scale TiO2 branch growth, characterized in that:

[0014] The fabrication steps for growing the micron-scale TiO2 backbone array are as follows:

[0015] 1) The three-dimensional porous material is immersed overnight in a titanium tetrachloride solution, wherein the titanium tetrachloride solution is an ethanol solution with a volume fraction of 1-5%, and the immersion time is 10-14 hours;

[0016] 2) The three-dimensional porous material was oxidized at 400℃ for 2 hours to generate a TiO2 coating and nanodots;

[0017] 3) The three-dimensional porous material is immersed in a mixture of acetone, hydrochloric acid and tetrabutyl titanate, and a high-temperature hydrothermal reaction is carried out to grow a nanowire array based on TiO2 nanodots. The volume ratio of acetone to hydrochloric acid is 2:1, the amount of tetrabutyl titanate added is 5-25% of the total volume of hydrochloric acid and acetone, and the hydrothermal conditions are 180-240℃ and 2-5 hours.

[0018] The preparation steps for growing platinum-doped nanoscale TiO2 branches are as follows:

[0019] 1) The electrodes for growing micron-sized TiO2 backbone arrays are immersed in a solution of ammonium fluorotitanate and boric acid, and chloroplatinic acid is used as a dopant to improve the conductivity and catalytic activity of the material. The solution is hydrothermally heated to 30-80℃ and maintained for 1-5 days to grow nano-sized TiO2 branches on the micron-sized TiO2 backbone array. The molar ratio of boric acid to ammonium fluorotitanate is 3:1, the concentration of boric acid is 30-80mM, and the concentration of chloroplatinic acid dopant is 0.1-2mM.

[0020] 2) The material is oxidized at 400℃ for 2 hours to transform the TiO2 crystal structure, that is, to prepare a platinum-doped dendritic TiO2 material;

[0021] The three-dimensional porous material is a carbon-based or metal-based porous conductive material;

[0022] The carbon-based material is any one of graphene sponge, graphite felt, and glassy carbon; the metal-based porous conductive material is any one of Ti foam, Ni foam, and Cu foam; the electrode material prepared by the above method is used as the anode, and the above-mentioned carbon-based or metal-based porous conductive material is used as the cathode to construct a filter-type nanowire electrochemistry and chloride / sulfate / oxidant synergistic oxidation technology for reducing intracellular resistance genes of drug-resistant bacteria in drinking water; the chloride is sodium chloride, potassium chloride, etc., and the sulfate is sodium sulfate, potassium persulfate; the oxidant is hypochlorous acid, chlorine, calcium hypochlorite, chlorine dioxide, chloramine, ozone, and hydrogen peroxide.

[0023] The dendritic TiO2 nanowire electrode prepared in this invention is achieved through the following technical solution: a micron-sized TiO2 array is grown on the surface of a porous structure of a three-dimensional electrode material; then, using the micron-sized TiO2 array as the main trunk, a platinum-doped TiO2 nanowire array is further grown on its surface as branches, thereby forming a dendritic TiO2 nanowire structure on a three-dimensional electrode. Nanowire electrochemistry can utilize the lightning rod effect of nanowires to form a confined strong electric field and a region with high electrocatalytic activity at the tip of the nanowire. The platinum-doped dendritic nanowire structure prepared in this invention has greater conductivity and specific surface area, providing more reactive sites, electrocatalytic activity, and confined strong electric field exposure sites, promoting the electroporation structure destruction of microorganisms and the production of higher concentrations of active free radicals to degrade intracellular i-ARGs.

[0024] This invention utilizes a filter-type nanowire electrochemistry constructed with dendritic TiO2 nanowire electrodes and a synergistic oxidation technology involving chloride / sulfate / oxidant. This technology can achieve efficient reduction of intracellular i-ARGs in ARBs through the following synergistic effects: 1) By utilizing the electroporation-barrier penetration effect induced by a confined strong electric field, the barrier structures such as bacterial EPS / wall / membrane are disrupted, promoting the penetration of oxidizing substances into the cell and reducing i-ARGs; 2) By utilizing the confined electrocatalysis-enhanced oxidation effect of nanowires, sulfates, chlorides, or oxidizing disinfectants are promoted to generate sulfate radicals such as SO4-·, RCS radicals such as Cl• and Cl2•−, or ROS radicals such as O2•− and •OH, thereby enhancing the oxidative reduction of intracellular i-ARGs.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] 1. This invention utilizes TiO2 micron-scale arrays grown on the surface of porous three-dimensional materials and platinum-doped TiO2 nanowires grown on the TiO2 micron-scale arrays to form a dendritic nanowire structure based on three-dimensional materials. The micro-nano spatial scale effect improves the electrode reaction sites, electrocatalytic activity, and confined strong electric field exposure sites, thereby enhancing the ARB structure destruction effect and the oxidation reduction efficiency of intracellular i-ARGs.

[0027] This invention enhances the reduction of intracellular i-ARGs in ARB cells through a platinum-doped dendritic TiO2 nanowire electrode. Platinum doping improves electrode conductivity and electrocatalytic performance, and chloride, sulfate, and oxidant are used as electrolytes to couple electroporation and electrochemical oxidation at the electrode interface. By inducing the formation of membrane pores in ARB cells through a confined strong electric field, the diffusion efficiency of electrochemically generated oxidative substances into the cell is enhanced, achieving a strategy of synergistic and efficient reduction of i-ARGs through membrane perforation and oxidative degradation. Attached Figure Description

[0028] Figure 1 Scanning electron microscope (SEM) images of the graphite felt carrier, the graphite felt modified with TiO2 coating, the graphite felt modified with micron-sized TiO2 backbone array, and the graphite felt modified with dendritic TiO2 nanowires, as described in Embodiment I of the present invention.

[0029] Figure 2 The platinum-doped dendritic TiO2 nanowire-modified graphite felt of Embodiment I of the present invention is used in an in-electrode filtration reaction device for treating intracellular resistance genes of drug-resistant bacteria in drinking water.

[0030] Figure 3 This is a comparison of the logarithmic reduction rate of intracellular i-ARGs in ARB cells by TiO2-modified graphite mats with different morphologies in Example I of the present invention.

[0031] Figure 4The logarithmic reduction rate of intracellular i-ARGs in ARBs by the synergistic technology under different chlorine doses (calculated as Cl2) in Example I of the present invention;

[0032] Figure 5 Scanning electron microscope images showing the destruction of ARB cell structure by single and synergistic techniques according to Embodiment I of the present invention.

[0033] In the diagram: 1. Water inlet; 2. Nanowire electrode; 3. Power supply; 4. Nanowire electrode; 5. Water outlet; 6. Water pump. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] See Figure 1-5 :

[0036] Example I

[0037] S1. Growth of micron-sized TiO2 backbone array on a three-dimensional carrier: Graphite felt was immersed in an ethanol solution with a volume fraction of 2.5% titanium tetrachloride for 12 hours, and then oxidized at 400 degrees for 2 hours to generate TiO2 nanodots.

[0038] S2. The material is immersed in a mixture of acetone, hydrochloric acid, and tetrabutyl titanate, and hydrothermally reacted at 240 degrees Celsius for 2 hours to grow a micron-line array based on TiO2 nanodots. The volume ratio of acetone to hydrochloric acid is 2:1, the amount of tetrabutyl titanate added is 10% of the sum of the volumes of hydrochloric acid and acetone, and the hydrothermal conditions are 200 degrees Celsius and 4 hours.

[0039] S3. Immerse the material in a mixture of ammonium fluorotitanate, boric acid and chloroplatinic acid, and keep it in a 50-degree water bath for 2 days.

[0040] S4. After being washed and dried with pure water, the TiO2 crystal form is transformed by oxidation at 400 degrees for 2 hours, thus obtaining the graphite felt modified with platinum-doped dendritic TiO2 nanowires.

[0041] In this embodiment, a graphite felt with a diameter of 25 mm and a thickness of 5 mm is used as the electrode carrier in step S1.

[0042] In this embodiment, the volume of the synthesis liquid in step S1 is 200 mL, corresponding to 6 graphite felts.

[0043] In this embodiment, the volume of the mixed liquid in step S2 is 40 mL of acetone and 20 mL of hydrochloric acid, the volume of tetrabutyl titanate is 6 mL, and the volume of the hydrothermal reactor is 100 mL.

[0044] In this embodiment, the molar ratio of boric acid to ammonium fluorotitanate in the solution of step S3 is 3:1, the boric acid concentration is 40 mM, and the chloroplatinic acid dopant concentration is 0.5 mM.

[0045] For the purpose of performance comparison, six graphite felts were immersed in a synthesis solution consisting of 30 mL of pure water, 30 mL of hydrochloric acid and 3.6 mL of water, and hydrothermally reacted at 150 degrees for 5 hours. After cleaning and drying, the graphite felts were oxidized at 400 degrees for 2 hours to convert the TiO2 crystal form, thus obtaining the TiO2-coated graphite felts.

[0046] The morphology of graphite felt, graphite felt modified with TiO2 coating, graphite felt modified with micron-sized TiO2 backbone array, and graphite felt modified with dendritic TiO2 nanowires were analyzed by scanning electron microscopy.

[0047] The results are as follows Figure 1 As shown, it can be clearly observed that the micron-sized TiO2 backbone array of the present invention is loaded onto graphite felt, forming a TiO2 "backbone" on the "graphite fiber"; it is found that nano-sized TiO2 branches grow on the micron-sized TiO2 backbone array, thereby forming a dendritic TiO2 nanowire electrode material.

[0048] Using unmodified graphite felt as the cathode, and using graphite felt modified with TiO2 coating, graphite felt modified with micron-sized TiO2 backbone array, graphite felt modified with undoped dendritic TiO2 nanowires, and graphite felt modified with platinum-doped dendritic TiO2 nanowires as the anode, a filter-type nanowire electrochemical / chlorine co-oxidation reaction device was constructed.

[0049] like Figure 2 As shown, an ARB bacterial suspension of 10⁶ CFU / mL E. coli was prepared, in which the intracellular i-ARGs of ARB consisted of 10⁶.89 copies / mL of tetracycline tet resistance genes (209 bp). The reaction was carried out under the conditions of DC power 0-4.0 V, flux 1500 L / h / m², and sodium hypochlorite 10 mg / L. EIS tests were performed using an electrochemical workstation, and the reaction internal resistance of the TiO₂-coated graphite felt was determined to be 10.7 Ω, the reaction internal resistance of the micron-sized TiO₂ backbone array-modified graphite felt was 6.3 Ω, the reaction internal resistance of the undoped dendritic TiO₂ nanowire-modified graphite felt was 4.5 Ω, and the reaction internal resistance of the platinum-doped dendritic TiO₂ nanowire-modified graphite felt was 2.1 Ω.

[0050] Further investigation was conducted to determine the logarithmic reduction rate of intracellular i-ARGs in the ARBs effluent from the corresponding device.

[0051] like Figure 3 As shown, the platinum-doped and dendritic nanowire-modified electrodes exhibit the best logarithmic reduction rate of intracellular i-ARGs in the ARB. For example, at a voltage of 3.5V, the platinum-doped dendritic TiO2 nanowire-modified graphite felt exhibits a logarithmic reduction rate of 5.2 log for intracellular i-ARGs in the ARB, the undoped dendritic TiO2 nanowire-modified graphite felt exhibits a logarithmic reduction rate of 2.6 log, the micron-scale TiO2 backbone array-modified graphite felt exhibits a logarithmic reduction rate of 1.7 log, and the TiO2 coating-modified graphite felt exhibits a logarithmic reduction rate of 0.9 log.

[0052] Figure 4 Data with a voltage of 0V represents the log reduction rate of intracellular i-ARGs in ARBs caused by a single 10 mg / L chlorine disinfection.

[0053] The effect of sodium hypochlorite dosage (as Cl2) on the logarithmic reduction rate of intracellular i-ARGs in a platinum-doped dendritic TiO2 nanowire-modified graphite felt device under DC conditions of 2.5V and a flux of 1500 L / h / m2 was further investigated. The synergistic effect was defined as the difference between the logarithmic reduction rate of i-ARGs achieved by synergistic oxidation technology and the logarithmic reduction rate of i-ARGs achieved by "single chlorine disinfection and single nanowire electrochemical technology." Single chlorine disinfection was assessed by directly evaluating the logarithmic reduction rate of i-ARGs by chlorine disinfectant, while single nanowire electrochemistry was assessed by directly evaluating the logarithmic reduction rate of i-ARGs without the addition of chlorine disinfectant.

[0054] Depend on Figure 4 It can be clearly observed that the synergistic oxidation technology can significantly enhance the reduction of i-ARGs at sodium hypochlorite concentration of 10 mg / L.

[0055] Depend on Figure 5 It can be clearly observed that the synergistic oxidation technology mainly promotes the infiltration of oxidants into the cell or the exfiltration of i-ARGs into the cell by disrupting the ARB cell structure, thereby enhancing the contact and degradation reaction between oxidants and i-ARGs.

[0056] Example II

[0057] Except for the following technical features, the other technical features in this embodiment are the same as those in Embodiment I:

[0058] In this embodiment, the electrode carrier in step S1 uses a graphene sponge with a diameter of 10 mm and a thickness of 5 mm.

[0059] In this embodiment, the titanium tetrachloride in the synthesis solution in step S1 is a 1% ethanol solution, and the immersion time is 14 hours.

[0060] In this embodiment, the volume of tetrabutyl titanate in the mixed liquid in step S2 is 8 mL.

[0061] In this embodiment, the boric acid concentration in the solution of step S3 is 30 mM, and the chloroplatinic acid dopant concentration is 2 mM.

[0062] In this embodiment, a graphene sponge electrode material modified with platinum-doped dendritic TiO2 nanowires was prepared.

[0063] Furthermore, a filter-type nanowire electrochemical / ozone synergistic oxidation reactor was constructed using platinum-doped dendritic TiO2 nanowire-modified graphene sponge as the anode and unmodified graphene sponge as the cathode, with ozone (O3) as the oxidant. Under conditions of 3.0 V DC, a flux of 1500 L / h / m², 106.67 copies / mL of intracellular β-lactam resistance genes (307 bp), and 1.5 mg / L O3, the synergistic device achieved a 5.4 log reduction in intracellular i-ARGs and a 4.6 log synergistic reduction effect.

[0064] Example 3

[0065] Except for the following technical features, the other technical features in this embodiment are the same as those in Embodiment I:

[0066] In this embodiment, the electrode carrier in step S1 uses Ti foam with a diameter of 30 mm and a thickness of 2.5 mm as the carrier.

[0067] In this embodiment, the titanium tetrachloride in the synthesis solution in step S1 is a 4% (v / v) ethanol solution, and the immersion time is 10 hours.

[0068] In this embodiment, the volume of tetrabutyl titanate in the mixed liquid in step S2 is 10 mL.

[0069] In this embodiment, the boric acid concentration in the solution of step S3 is 50 mM, and the chloroplatinic acid dopant concentration is 1.5 mM.

[0070] In this embodiment, a Ti foam electrode material modified with platinum-doped dendritic TiO2 nanowires was prepared.

[0071] Furthermore, a filter-type nanowire electrochemical / chloride-co-oxidation reaction device was constructed using platinum-doped dendritic TiO2 nanowire-modified Ti foam as the anode, unmodified Ti foam as the cathode, and sodium chloride as the electrolyte. The reaction was carried out under the conditions of 6.0 V DC, 1000 L / h / m² flux, 106.96 copies / mL of intracellular aminoglycoside aac(3)-II resistance gene (186 bp), and 2 mM sodium chloride. The co-reaction device achieved a 4.3 log reduction in intracellular i-ARGs and a 3.7 log co-reduction effect.

[0072] Example IV

[0073] Except for the following technical features, the other technical features in this embodiment are the same as those in Embodiment I:

[0074] In this embodiment, the electrode carrier in step S1 uses glassy carbon with a diameter of 35 mm and a thickness of 2.0 mm.

[0075] In this embodiment, the titanium tetrachloride in the synthesis solution in step S1 is a 5% ethanol solution, and the immersion time is 14 hours.

[0076] In this embodiment, the volume of tetrabutyl titanate in the mixed liquid in step S2 is 15 mL.

[0077] In this embodiment, the boric acid concentration in the solution of step S3 is 80 mM, and the chloroplatinic acid dopant concentration is 0.5 mM.

[0078] In this embodiment, a glassy carbon electrode material modified with platinum-doped dendritic TiO2 nanowires was prepared.

[0079] Furthermore, a filter-type nanowire electrochemical / sulfate-salt synergistic oxidation reaction device was constructed using platinum-doped dendritic TiO2 nanowire-modified glassy carbon as the anode, unmodified glassy carbon as the cathode, and sodium chloride as the electrolyte. The reaction was carried out under the conditions of 10.0 V DC, a flux of 1200 L / h / m², 107.43 copies / mL of intracellular sulfonamide resistance gene (246 bp), and 5 mM sodium sulfate. The synergistic device achieved a 5.7 log reduction in intracellular i-ARGs and a 5.2 log synergistic reduction effect.

[0080] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0081] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. The application of an electrode material with reduced intracellular resistance genes in drug-resistant bacteria, comprising micron-scale TiO2 backbone array growth and platinum-doped nano-scale TiO2 branch growth, characterized in that: The fabrication steps for growing the micron-scale TiO2 backbone array are as follows: 1) The three-dimensional porous material is immersed overnight in a titanium tetrachloride solution, wherein the titanium tetrachloride solution is an ethanol solution with a volume fraction of 1-5%, and the immersion time is 10-14 hours; 2) The three-dimensional porous material was oxidized at 400℃ for 2 hours to generate a TiO2 coating and nanodots; 3) The three-dimensional porous material is immersed in a mixture of acetone, hydrochloric acid and tetrabutyl titanate, and a high-temperature hydrothermal reaction is carried out to grow a nanowire array based on TiO2 nanodots. The volume ratio of acetone to hydrochloric acid is 2:1, the amount of tetrabutyl titanate added is 5-25% of the total volume of hydrochloric acid and acetone, and the hydrothermal conditions are 180-240℃ and 2-5 hours. The preparation steps for growing platinum-doped nanoscale TiO2 branches are as follows: 1) The electrodes for growing micron-sized TiO2 backbone arrays are immersed in a solution of ammonium fluorotitanate and boric acid, and chloroplatinic acid is used as a dopant to improve the conductivity and catalytic activity of the material. The solution is hydrothermally heated to 30-80℃ and maintained for 1-5 days to grow nano-sized TiO2 branches on the micron-sized TiO2 backbone array. The molar ratio of boric acid to ammonium fluorotitanate is 3:1, the concentration of boric acid is 30-80mM, and the concentration of chloroplatinic acid dopant is 0.1-2mM. 2) The material is oxidized at 400℃ for 2 hours to transform the TiO2 crystal structure, that is, to prepare a platinum-doped dendritic TiO2 material; The three-dimensional porous material is a carbon-based or metal-based porous conductive material; The carbon-based material is any one of graphene sponge, graphite felt, and glassy carbon; the metal-based porous conductive material is any one of Ti foam, Ni foam, and Cu foam; the electrode material prepared by the above method is used as the anode, and the above-mentioned carbon-based or metal-based porous conductive material is used as the cathode to construct a filter-type nanowire electrochemistry and chloride / sulfate / oxidant synergistic oxidation technology for reducing intracellular resistance genes of drug-resistant bacteria in drinking water; the chloride is sodium chloride or potassium chloride, the sulfate is sodium sulfate or potassium persulfate; the oxidant is hypochlorous acid, chlorine, calcium hypochlorite, chlorine dioxide, chloramine, ozone, or hydrogen peroxide.

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