METHOD FOR PURIFICATION OF WATER AND WATER PURIFICATION SYSTEM

Abstract

The invention relates to a method and a system for purification of water in a water purification system. The water purification system comprises first and second mixing reactors, first and second flotation reactors and first and second filters all serially and fluidly connected in a flow direction of the water as well as an electrolyzer. During the process, electrochemical synthesis of the reagents takes place in the cathode and anode chambers of the electrolyzer, respectively. Moreover, the electrochemically synthesized catholyte and anolyte are dosed into the water kept in the first and second mixing reactors, respectively. Then the mixtures in the first and second mixing reactors are mixed. After that, the flow of the treated water leaving the mixing reactors is passed through the first and second flotation reactors and afterwards through the first and second filters downstream of the first and second mixing reactors.

Claims

1. A method for purification of water using a water purification system wherein the water purification system comprises: a first mixing reactor, a first flotation reactor, a first filter, a second mixing reactor, a second flotation reactor, and a second filter, all serially and fluidly connected in this order in a flow direction of the water, as well as an electrolyzer comprising a cathode chamber and an anode chamber, the method comprising the following steps: electrochemically synthesizing a catholyte and an anolyte each containing reagents in the cathode and the anode chamber of the electrolyzer, respectively, dosing of one of the electrochemically synthesized catholyte and anolyte into the water and mixing the one of the catholyte and anolyte with the water in the first mixing reactor, passing the flow of the treated water leaving the first mixing reactor through the first flotation reactor and through the first filter, dosing of the other one of the electrochemically synthesized catholyte and anolyte into the treated water leaving the first filter and mixing the other one of the catholyte and anolyte with the water in the second mixing reactor, and passing the flow of the treated water leaving the second mixing reactor through the second flotation reactor and through the second filter.

2. The method according to claim 1, wherein the electrochemically synthesized catholyte and anolyte are dosed into the water and/or into the treated water leaving the first filter in the form of a gas-liquid mixture.

3. The method according to claim 1, wherein the electrochemically synthesized catholyte and anolyte are dosed into the water and/or into the treated water leaving the first filter in the form of a gas-liquid mixture.

4. The method according to claim 1, wherein an initial electrolyte solution feeding the cathode chamber and/or the anode chamber of the electrolyzer, is a sodium chloride solution.

5. The method according to claim 1, wherein an initial electrolyte solution, feeding the cathode chamber and/or the anode chamber of the electrolyzer is a mixture of sodium carbonate and sodium chloride.

6. The method according to claim 1, wherein the initial electrolyte solution feeding the electrolyzer is supplied only to one of the cathode and anode chamber, and purified water is fed into the other one of the cathode and anode chamber.

7. The method according to claim 1, wherein the composition and properties of the reagents obtained in the electrolyzer are controlled by varying a current strength and/or a feed rate into each of the cathode and anode chambers of the electrolyzer and/or the pressure drop across a membrane or diaphragm of the electrolyzer.

8. The method according to claim 1, wherein a number of electrolyzers together with the respective associated mixers, flotation reactors and filters and/or the order of sequential input of the electrochemically synthesized catholyte and anolyte into the stream of water to be purified is selected depending on the chemical composition of the water and required extent of water purification.

9. The method according to claim 1, wherein the same initial electrolyte solution is supplied to both the anode and cathode chamber of the electrolyzer.

10. The method according to claim 1, wherein the purified water fed into the other one of the cathode and anode chamber of the electrolyzer is softened, and wherein the purified water has a mineral content of not more than 0.3 g/l.

11. The method according to claim 2, wherein the electrochemically synthesized catholyte and anolyte are dosed into the water and/or into the treated water leaving the first filter in the form of the gas-liquid mixture under a pressure of 0.1 to 2.5 bar.

12. The method according to claim 3, wherein the gas-liquid mixture has a ratio of liquid to gas by volume in a range of 1:10-1:1000.

13. The method according to claim 4, wherein the sodium chloride solution has a sodium chloride concentration in the range from 0.5 to 50 g/l.

14. The method according to claim 5, wherein the mixture of sodium carbonate and sodium chloride has a sodium carbonate to sodium chloride molar ratio of 1:10 to 1:100 and/or a total concentration of sodium carbonate and sodium chloride in the range from 0.5 to 50 g/l.

15. The method according to claim 10, wherein the purified water is fed into the cathode chamber, and the purified water contains mainly sulfates, chlorides, and carbonates of sodium and potassium as dissolved solids.

16. A water purification system comprising: an electrolyzer comprising a cathode chamber and an anode chamber and adapted for electrochemically synthesizing a catholyte and an anolyte containing reagents from an initial electrolyte solution, a water flow path for supplying and transporting water, a first mixing reactor arranged in the water flow path and fluidly connected to one of the cathode chamber and the anode chamber of the electrolyzer and for mixing the water supplied to the water purification system with the one of the catholyte and analyte synthesized in the electrolyzer, a first flotation reactor arranged in the water path downstream of the first mixing reactor and a first filter for water purification arranged downstream of the first flotation reactor, a second mixing reactor arranged in the water supply path downstream of the first filter and fluidly connected to the other one of the cathode chamber and the anode chamber of the electrolyzer for mixing the treated water leaving the first filter with the other one of the catholyte and analyte synthesized in the electrolyzer, and a second flotation reactor arranged in the water path downstream of the second mixing reactor and a second filter for water purification arranged downstream of the second flotation reactor.

17. The water purification system according to claim 16, wherein the electrolyzer is a diaphragm flow-through electrolyzer.

18. The water purification system according to claim 16, wherein the first mixing reactor and/or the second mixing reactor is a vortex mixer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] FIG. 1 presents a basic diagram for fresh water purification.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

[0046] FIG. 1 shows a water purification system in accordance with a preferred embodiment of the present invention.

[0047] Pressurized water (raw water), in particular, natural fresh water, enters the highly efficient main technological water purification system (process) consisting of a series—connected first mixing reactor 1 (mixer 1), a first flotation reactor 2, a first filter 3, a first mixing reactor 4 (mixer 4), a second flotation reactor 5 and a second filter 6, all serially and fluidly connected in this order in a flow direction of the water, and leaves the process as ready-to-use by consumer (drinking (purified) water). The first mixing reactor 1 (mixer 1), first flotation reactor 2, first filter 3, second mixing reactor 4 (mixer 4), second flotation reactor 5 and second filter 6 are connected by a fluid carrying line. The first mixing reactor 1 is connected on the outlet side to the first flotation reactor 2. The first flotation reactor 2 is connected on the outlet side to the first filter 3. Downstream of the first filter 3, the second mixing reactor 4 is integrated into the fluid-carrying line. The second flotation reactor 5 is arranged downstream of the second mixing reactor 4. The second flotation reactor 5 is connected on the outlet side to the second filter 6. Further, the water purification system comprises a diaphragm flow-through electrolyzer 7, wherein a cathode chamber of the electrolyzer 7 is fluidly connected to the first mixer 1 and an anode chamber of the electrolyzer 7 is fluidly connected to the second mixer 4. The water purification system comprises a catholyte supply path and an anolyte supply path. The cathode chamber and the anode chamber of the electrolyzer 7 are on the inlet side fluidly connected via a catholyte supply line for supplying the catholyte to the cathode chamber and an anolyte supply line for supplying an anolyte to the anode chamber with dosing pumps 8 and 9, respectively. Products of electrolysis are dosed by the dosing pumps 8 and 9, the outputs of which are connected to the anode and cathode chambers of electrolytic cells of the diaphragm flow-through electrolyzer 7. Products of electrolysis are dosed under the pressure. The pressure in the electrolysis chambers of the diaphragm flow-through electrolyzer 7 is regulated “up to itself” by reducers 10 and 11 which are arranged in the fluid-carrying line downstream of the first and second mixers 1, 4 and upstream of the electrolyzer 7 and is controlled by means of pressure gauges 12 and 13 equipped with separators 14 and 15. The cathode chamber and the anode chamber of the electrolyzer 7 are each connected on the outlet side to an intermediate retention tank 17 and an intermediate retention tank 16. The intermediate retention tank 17 and the intermediate retention tank 16 are in turn connected on the outlet side to the reducers 10 and 11. Intermediate retention tanks 16 and 17 are used to feed products of electrolysis to the first and second mixers 1 and 4 and to remove the access amount of products of electrolysis from the process. The bottom parts of the retention chambers are connected to drainage lines by hydraulic resistances 18 and 19 that are adjustable from the fully locking to the not fully locking position.

[0048] To protect the dosing pumps 8, 9 from the products of electrolysis, check vales 20 and 21 are installed on the fluid carrying-lines of electrolyte entrance to the anode and cathode chambers of electrolyzer 7 upstream of the dosing pumps 8 and 9.

[0049] Discharge lines of flotation reactors 2 and 5 are equipped with control valves 22 and 23 that are installed to regulate the discharge volume of gas-liquid products of electrolysis.

[0050] Depending on the tasks of water purification process, one of the electrochemically synthesized catholyte and anolyte from the diaphragm flow-through electrolyzer 7 can be fed into the first mixer 1. In this case, respectively the other one of the electrochemically synthesized catholyte and anolyte will be dosed into the second mixer 4. A typical method of water purification for the single homes and small villages starts with the step of dosing the catholyte into the first mixer 1, and the anolyte is dosed into the second mixer 4. FIG. 1 describes this method of water purification. Example of the opposite water purification process, where the first step consists of dosing the anolyte into the first mixer 1, are purification of water with high microbial load, for example standing surface water. To simultaneously guaranty efficient protection of water from microbial growth for prolong time by providing residual oxidants and increasing the purification process efficiency, a second similar multistage process with reverse sequence of dosing of products of electrolysis can be added.

[0051] The input lines of the dosing pumps 8 and 9 consist of a flexible tubing for dosing initial electrolyte solutions, sodium chloride and sodium carbonate or sodium bicarbonate, from tanks 24 and 25, which are fluidly connected, and are equipped with a protective screen. Initial electrolyte solutions pumped into the cathode and anode chambers of the electrolyzer 7 may have different concentrations and/or different chemical compositions. It is also possible to feed the same initial electrolyte solution into both chambers of the electrolyzer 7 or to supply one of the chambers with the electrolyte, and the other chamber with purified water instead. In that case, as the water passes through one chamber of the electrolyzer 7, water becomes saturated with the corresponding ions from the other electrode chamber. The electrochemical process and products of electrolysis are controlled by regulating the flow rates of the electrolyte solution or purified water into the anode and cathode chambers of the electrolyzer 7 and/or the concentration of the dosing electrolyte and/or the applied current.

[0052] If softened, purified water with a mineralization of not more than 0.3 g/l, containing mainly sulfates, chlorides and carbonates of sodium and potassium as dissolved solids, is introduced into the cathode chamber of the electrolyzer instead of the electrolyte, then the products of cathode reactions are compounds formed by the reactions of electrochemical cathode decomposition of water and aqueous solutions of dissolved solids:

2H.sub.2O+2e.fwdarw.H.sub.2+2OH.sup.−; O.sub.2+e.fwdarw.O.sub.2.sup.−; O.sub.2+H.sub.2O+2e.fwdarw.HO.sub.2.sup.−+OH.sup.−;

e.sub.cathode+H.sub.2O.fwdarw.e.sub.aq; H.sup.++e.sub.aq.fwdarw.H*; H.sub.2O+e.sub.aq.fwdarw.H*+OH.sup.−

HO.sub.2.sup.−+H.sub.2O+e.fwdarw.HO*+2OH.sup.−; O.sub.2+2H.sup.++2e.fwdarw.H.sub.2O.sub.2;

Na.sup.++OH.sup.−.fwdarw.NaOH; K.sup.++OH.sup.−.fwdarw.KOH.

[0053] Electrochemically activated solution of products of cathode reduction, such as hydroxyl anion (OH.sup.−), superoxide anion (O.sub.2.sup.−), peroxide anion (HO.sub.2.sup.−), molecular anion of water-exciton (H.sub.2O.sup.−), hydrated electron (e.sub.aq), atomic hydrogen (H*) and the hydroxyl radical (HO*), possess an extremely high reactivity. The gas phase of catholyte is represented by wet hydrogen containing micro-droplets of moisture saturated with highly active products of cathodic reactions, including alkali metal hydrides. The concentration of monovalent metal hydroxides generated in the cathode chamber of the reactor of the electrolytic cell does not exceed 1-2 g/l. The pH value of catholyte is in the range of 13-14, which is caused by the extremely high activity of the products of cathodic electrochemical reactions (see Bakhir V. M., Pogorelov A. G., Universal Electrochemical Technology for Environmental Protection. International Journal of Pharmaceutical Research & Allied Sciences, 2018, 7 (1): 41-57. ISSN: 2277-3657 CODEN (USA): IJPRPM. Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Moscow Region, Pushino, Russia-[2]). However, the products of non-equilibrium electrochemical reactions contained in the microdroplets of gaseous products of electrolysis have a physicochemical activity that is much higher than the corresponding activity of the liquid media—catholyte and anolyte. Research of the proposed process during its development showed that the microdroplets of moisture in the gaseous products of anodic and cathodic reactions have an electric charge corresponding to the polarity of the electrode and contain highly active metastable compounds that are unable to exist in a large volume of water for more than a few tenths of a second. It was found that wet gaseous products of anodic and cathodic electrochemical reactions can shift the redox potential of water above the redox potential of water decomposition, specific to the extreme pH values. For example, when fresh (salinity of 0.25 g/l) tap water was mixed with gaseous products of cathodic reactions of electrolysis of the same water in the modular element MB-11T-07 [Patent GB 2479286], the ORP values were minus 900 mV, in the scale of normal hydrogen electrode, with an initial pH of water (before mixing) equal to 7.0, and a pH of water equal to 7.5, after mixing with gaseous products from the cathode chamber of the MB element. Also, the values of the redox potential of the same water mixed with the gaseous products of anode oxidation of the same water exceeded plus 1400 mV, in the scale of the normal hydrogen electrode, at a water pH of 6.5. Used equipment is described in Universal Electrochemical Technology for Environmental Protection. International Journal of Pharmaceutical Research & Allied Sciences (Bakhir V. M., Pogorelov A. G., Universal Electrochemical Technology for Environmental Protection. International Journal of Pharmaceutical Research & Allied Sciences, 2018, 7 (1): 41-57. ISSN: 2277-3657 CODEN (USA): IJPRPM. Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Moscow Region, Pushino, Russia-[2]).

[0054] The lifetime of the metastable substances in the microdroplets of wet products of electrolysis can range from several seconds to several minutes in the case of their isolation from the environment and depends on the physicochemical conditions of the wet gas interface. Microdroplets of liquid have an electric charge that keeps them in a gaseous medium at a distance from each other and prevents them from converging. For the cathode products of electrolysis, such a medium is hydrogen, where the droplets are negatively charged, for anode ones—chlorine, chlorine dioxide, oxygen, ozone, where the charge of the droplets is positive. When mixing a wet electrolysis gas with water, an instantaneous reaction occurs between highly active products of electrolysis and water and substances dissolved in it.

[0055] It was found that the redox potential of water shifts to the negative values by up to 300-800 mV as a result of dosing the gaseous and liquid cathodic products of electrolysis in ratio of 1 part of electrolytic products to 1 million parts of water. It also results in almost instant coagulation of the colloidal particles due to significant change in the activity of the dispersion medium, due to the reduction of redox potential, in comparison, the electrokinetic potential of colloidal particles is negligible.

[0056] In the course of experimental studies, it was found that the change in the ORP of water as a result of the introduction of gaseous or liquid products of cathodic electrochemical treatment in a weight ratio of 1 part reagent to 1 million parts of water changes towards negative values around 300-800 mV depending on the chemical composition of water. At the same time, almost instantaneous coagulation of colloids is observed, which is caused by a sharp change in the activity of the dispersion medium, accompanied by a decrease in the redox potential, in comparison with which the electrokinetic potential of colloidal particles is negligible.

[0057] The rapid destabilization of colloidal suspensions (coagulation) is followed by the flocculation process. The completion of the flocculation process with the formation of flakes and agglomerates of colloids occurs in the sediment layer of coagulated particles on the filter. The initial shift of the redox potential of water, its after mixing with the cathode or anodic products of electrolysis, as a rule, returns to equilibrium or close to it after the filtration stage.

[0058] When purifying water from ground or surface sources, for which the standard purification process (coagulation, flocculation, sedimentation, filtration, disinfection) is optimal, the stage of introduction of the catholyte into the first mixer 1 and the anolyte into the second mixer 4 is applied. The introduction of the gas-liquid mixture of highly active products of cathode process in the post cathode—first mixer 1 is accomplished by pump 8 of the electrochemical unit of the water purification system. In the first mixer 1 the reaction of interaction of active cathode products with water impurities occurs by injecting the reagent catholyte into the water stream. Since electrochemically activated cathode reduction products have anomalous chemical reactivity and catalytic ability, the speed of their interaction with dissolved impurities is many times greater than the speed of interaction of solutions of stable chemicals that are commonly used in standard water purification technologies. In the first mixer 1 reactions of formation of insoluble hydroxides of polyvalent metals, which include all heavy metals, as well as reactions of formation of hydroxides of iron, manganese, strontium, nickel, aluminum, calcium, and magnesium take place. The generalized reaction of formation of insoluble metal hydroxides is described by the equation:

Me.sup.n++n(OH.sup.−).fwdarw.Me(OH)n,

where Me is a polyvalent metal ion; and n is valence of the metal ion.

[0059] Insoluble flakes and microcrystals of heavy metal hydroxides, as well as hydroxides of iron, manganese, copper, zinc, calcium, magnesium, possess a very high sorption capacity and form complex compounds with various organic impurities dissolved in water. Upon entering the first flotation reactor 2 (for the purification process described here), a significant part of insoluble hydroxides of polyvalent metals present in the form of micro flakes with adsorbed organic compounds are removed together with a small amount of water (not more than one percent of the treated water stream) through the control valves 22 of the first flotation reactor 2. The moving force of the phase separation becomes the hydrogen bubbles that adhere to the surface of hydroxide micro-flakes and float them to the top of the first flotation chamber 2 to its fitting. The treated water together with the remaining hydroxide particles passes through the first filter 3, cartridge or quartz sand, where the remaining amount of microparticles, including the colloidal fraction, is separated. The removal of the colloidal particles on the first filter 3 is achieved by the electrokinetic effect in the newly formed hydroxide layer. The precipitates of hydroxides that accumulate on the filtration surface under the conditions of high reducing potential, condense under the force of strong electrostatic interaction of solids by forming an electron-donor porous structure, that comprise an electrosorption layer. When water is passed through this layer, formed on the filtering surface of any nature, the colloidal particles of hydroxides with organic compounds adsorbed on their surface are efficiently removed from the filtering water. Such electrosorption filters are the most effective for filtering out organic compounds with neutral or positively charged hydrated groups.

[0060] In the process of anode treatment of the same water passed through the anode chamber of diaphragm flow-through electrolyzer 7 by the dosing pump 9 (8) the following main chemical reactions take place simultaneously:

2H.sub.2O−4e.fwdarw.4H.sup.++O.sub.2; O.sub.2+H.sub.2O−2e.fwdarw.O.sub.3+2H.sup.+; 2H.sub.2O−2e.fwdarw.2H.sup.++H.sub.2O.sub.2;

3H.sub.2O−6e.fwdarw.O.sub.3+6H.sup.+; H.sub.2O−2e.fwdarw.*2H.sup.++O*; H.sub.2O−e.fwdarw.H.sup.++OH*;

OH.sup.−−e.fwdarw.HO*; O.sub.2+2OH.sup.−.fwdarw.3e.fwdarw.O.sub.3+H.sub.2O; 3OH.sup.−−2e.fwdarw.HO.sub.2.sup.−+H.sub.2O;

H.sub.2O.sub.2−e.fwdarw.HO.sub.2*+H*; H.sub.2O−e.fwdarw.HO*+H.sup.+; H.sub.2O.sub.2−e.fwdarw.HO.sub.2*+H.sup.+;

[0061] When a cleaning water or an auxiliary electrolyte is passed through the anode chamber or from the cathode chamber through the diaphragm, the anions of chlorides, sulfates or carbonates together with molecular chlorine, ozone and chlorine dioxide convert into hypochlorous acid, peroxocarbonate and persulfate, with their conversion rate being proportional to the concentration and their electrochemical equivalents:

Cl.sup.−+4OH.sup.−−5e.fwdarw.ClO.sub.2+2H.sub.2O; Cl.sup.−+H.sub.2O−2e.fwdarw.HClO+H.sup.+;

Cl.sup.−+2H.sub.2O−5e.fwdarw.ClO.sub.2+4H.sup.+; 2SO.sub.4.sup.2−−2e.fwdarw.S.sub.2O.sub.8.sup.2−; 2H.sub.2CO.sub.3−2e.fwdarw.H.sub.2C.sub.2O.sub.6+2H.sup.+.

[0062] After coming out of the first filter 3 water enters the second mixer 4, where it mixes with the products of anode oxidation of the diaphragm flow-through electrolyzer 7 which are dosed by dosing pump 9 into the second mixer 4.

[0063] The main active ingredients of products of anode oxidation, also called the electrochemically activated anolyte, is a mixture of peroxide compounds—hydrogen peroxide (H.sub.2O.sub.2), peroxide anion (HO.sub.2.sup.−), singlet molecular oxygen (.sup.1O.sub.2), superoxide anion (O.sub.2.sup.−), ozone (O.sub.3), oxygen radical (O*) and chlorine-oxygen compounds—hypochlorous acid (HClO), hypochlorite-radical (ClO*), dichlorine monoxide (Cl.sub.2O) and chlorine dioxide (ClO.sub.2).

[0064] All these substances are eubiotics, i.e. naturally produced by the human body, since the basis of pinocytosis and lysis of bacteria by phagocytes is the electrochemical synthesis of such substances from blood plasma.

[0065] Spontaneous decomposition of hydrogen peroxide in an aqueous solution is accompanied by the formation of compounds with very high antimicrobial activity (the corresponding chemical reactions are shown in parentheses): HO.sub.2.sup.−—hydroperoxide anion (H.sub.2O.sub.2+OH.sup.− .fwdarw.HO.sub.2.sup.−+H.sub.2O); O.sub.2.sup.2−—peroxide anion (OH.sup.−+HO.sub.2.sup.− .fwdarw.O.sub.2.sup.2−+H.sub.2O); O.sub.2.sup.−—superoxide anion (O.sub.2.sup.2−+H.sub.2O.sub.2.fwdarw.O.sub.2.sup.−+OH.sup.−+OH*); HO.sub.2*—hydrogen peroxide radical (HO*+H.sub.2O.sub.2.fwdarw.H.sub.2O+HO.sub.2*); HO.sub.2—superoxide of hydrogen (O.sub.2.sup.−+H.sub.2O.fwdarw.HO.sub.2+OH.sup.−). At the same time, it is possible to form an extremely reactive singlet oxygen .sup.1O.sub.2: (ClO.sup.−+H.sub.2O.sub.2.fwdarw..sup.1O.sub.2+H.sub.2O+Cl.sup.−). It was experimentally established that the molecular oxygen radical anion O.sub.2.sup.− is involved in the phagocytosis reactions, by one of the ways described above.

[0066] It is known that the formation of active free radicals ClO*, Cl*, HO* is possible in an aqueous media in the presence of HClO and ClO.sup.−: (HClO+ClO.sup.−.fwdarw.ClO*+Cl.sup.−+HO*). Active hypochlorite radicals ClO* can take part in the formation of oxygen radical (O*) and hydroxyl radical (HO*): (ClO*+ClO.sup.−+OH.sup.−.fwdarw.Cl.sup.−+2O*+OH*). Further a chain reaction occurs during the formation of chlorine radical: OH*+Cl.sup.−.fwdarw.Cl*+OH.sup.−. The resulting radicals, atomic oxygen radicals, take part in the destruction of the microorganisms, by interacting with biopolymers, which could be oxidized, for example, by the following reactions:

RH.sub.2+OH*.fwdarw.RH*+H.sub.2O;

RH.sub.2+C*.fwdarw.RH*+HCl;

RH.sub.2+O*.fwdarw.RH*+OH*.

[0067] A chain of metastable compounds, formed in the process of phagocytosis, is a very effective biocide, as it participates in multitarget reactions of irreversible disruption of the vital functions of biopolymers of microorganisms at the level of electron transfer reactions. Metastable particles with different values of the electrochemical potential have a universal spectrum of action, i.e. they possess a biocidal effect on all large systematic groups of microorganisms (bacteria, mycobacteria, viruses, fungi, spores) without harming the human cells and other higher organisms, i.e. somatic animal cells as part of a multicellular system.

[0068] In the traditional methods of removing ions of bivalent iron and manganese, aeration (oxidation by air bubbling) is most often used, and chlorine, ozone, and potassium permanganate are used as oxidizing agents in mechanical filtration of water on sand or activated carbon loads. However, the effectiveness of these technologies is low, because the process of oxidation and the formation of flakes is rather long time consuming when using reagents in a thermodynamically equilibrium state.

[0069] In case of metastable reagents, the oxidation process proceeds almost instantly due to the high chemical activity of those reagents in addition to catalytic activities of the electron-accepting media. More to add, in the process of water purification with products of anode oxidation reaction of microbial decontamination completes almost instantly, microbial contamination of all types and forms (bacteria, mycobacteria, viruses, fungi, spores), microbial toxins, other organic compounds, including herbicides, pesticides, hormones, antibiotics, antidepressants are destroyed by oxidants. The destruction of living and inanimate organic matter occurs as a result of oxidation of products of anode electrochemical reactions in a catalytically active medium. In particular, organic manganese and iron that are difficult to remove from water are effectively removed when water is mixed with the products of anodic oxidation:

Fe(OH).sub.2+OH.sup.−−e.fwdarw.Fe(OH).sub.3;

2Fe(OH).sub.2−2e.fwdarw.Fe.sub.2O.sub.3+H.sub.2O+H.sup.+;

Mn.sup.2++3H.sub.2O−2e.fwdarw.Mn.sub.2O.sub.3+6H.sup.+;

Fe(OH).sub.2+H.sub.2O−e.fwdarw.Fe(OH).sub.3+H.sup.+;

Mn.sup.2++2H.sub.2O−2e.fwdarw.MnO.sub.2+4H.sup.+;

Mn.sup.2++O.sub.3+H.sub.2O.fwdarw.MnO(OH).sub.2+H.sup.++O.sub.2;

Mn.sup.2++O.sub.3+H.sub.2O.fwdarw.MnO.sub.2+H.sup.++O.sub.2.

[0070] The invention is illustrated by the following examples, which, however, do not exhaust all the opportunities of the invention.

EXAMPLES

Example 1

[0071] In the example a device assembled according to the FIG. 1 is used. The diaphragm flow-through electrolyzer in the device is represented by the flow-through electrochemical modular element MB-11T-07, manufactured in accordance with the patent GB 2479286. The tubular electrodes of the element and the ceramic ultrafiltration diaphragm installed between them are coaxially arranged. Extended electrode chambers, which are narrow annular gaps slightly wider than one millimeter between the walls of the electrodes and the diaphragm, working under increased pressure with a constant release of gas bubbles on the surface of the electrodes, provide conditions for the flow of liquids in the mode of displacement while simultaneously mixing at a significant pressure drop on the diaphragm. In modern alternative diaphragm flow-through electrolyzers, a similar set of features is absent. This allows us to refer to the flow-through electrochemical modular diaphragm element MB as an electrolyzer.

[0072] Water from an artesian well with the following composition was treated: chlorides—133 mg/l, sulfates—78 mg/l, nitrates—9 mg/l, nitrites—1.2 mg/l, iron—1.9 mg/l, magnesium—51 mg/l, calcium—64 g/l, manganese—1.2 mg/l, surfactants—1.1 mg/l, active chlorine—0 mg/l, total microbial count (TMC)—168 CFU/ml. It was supplied with a flow rate of 800 l/h into the system; the outflow through the drainage outlets of flotation reactors 2, 5 was 4 liters per hour. An electrolyte solution of sodium chloride and sodium bicarbonate mixture with a concentration of 10 g/l NaCl and 1 g/l NaHCO.sub.3, respectively, was fed into the cathode chamber of the electrochemical element (diaphragm flow-through electrolyzer), and water free from suspended solids was fed into the anode chamber. The current applied to the MB element was 5 amps at 8 volts. As the result of the purification process, purified water had the following characteristics: chlorides—135 mg/l, sulfates—75 mg/l, nitrates—10 mg/l, nitrites—less than 0.01 mg/l, iron—0.01 mg/l, magnesium—45 mg/l, calcium—51 g/l, manganese—0.01 mg/l, surfactants—0.1 mg/l, free chlorine—0.15 mg/l, TMC—0 CFU/ml. That is, the indicators of purified water met sanitary standards for drinking water. The service life of the system during the tests was 150 hours, no biofilms or decrease in the purification process efficiency was observed.

Example 2

[0073] Water from the same source as described in example 1, and at a flow rate of 800 l/h, was fed to the same purification system as described in example 1. The electrolyte solution of sodium chloride and sodium carbonate with concentrations of 5 g/l and 0.5 g/l, respectively, was fed to the cathode and anode chambers of the electrolyzer. The applied current across electrolytic cell was 4.5 amperes at a voltage of 6.2 volts. At the outlet of the purification system, the purified water had the following characteristics: chlorides—130 mg/l, sulfates—74 mg/l, nitrates—10 mg/l, nitrites—less than 0.01 mg/l, iron—0.01 mg/l, magnesium—43 mg/l, calcium—52 g/l, manganese—0.01 mg/l, surfactants—0.07 mg/l, free chlorine—0.1 mg/l, TMC—0 CFU/ml. The purified water met the sanitary standards for drinking water. The service life of the system during the testi was 100 hours, no biofilms or decrease in the purification process efficiency were observed.

Example 3

[0074] A device assembled according to the process presented on FIG. 1 was used, with the same electrolyzer as in example 1. The difference was in the sequence of feeding the electrolysis products: A mixture of oxidants from the anode chamber of the electrolyzer was fed to the first mixer 1, and a mixture of products of cathodic electrochemical reactions was fed to the second mixer 4. A solution of sodium chloride 20 g/l and sodium carbonate 1 g/l was fed to the cathode chamber of the electrolyzer. Purified water obtained in the same system was fed into the anode chamber by a dosing pump under a pressure of 0.2 bar greater than in the cathode chamber. The applied current through the electrolyzer was 5 amperes at a voltage of 9 volts. The surface water (lake) was processed with the following compositions: chlorides—18 mg/l, sulfates—220 mg/l, nitrates—15 mg/l, nitrites—0.9 mg/l, iron—0.6 mg/l, active chlorine—0 mg/l, total microbial count (TMC)—more than 6000 CFU/ml. The flow rate of water was 600 liters per hour. At the end of the purification process, water had the following characteristics: chlorides—18 mg/l, sulfates—210 mg/l, nitrates—14 mg/l, nitrites—less than 0.01 mg/l, iron—0.01 mg/l, free chlorine—0.07 mg/l, TMC—0 CFU/ml.

Example 4

[0075] The purification process shown in FIG. 1 was used. Water was purified from a ground water source with a total mineralization of 0.3 g/l. The flow rate of water was 800 liters per hour. Distilled water was fed to the cathode chamber of the electrolyzer (element MB-11T-07), and sodium chloride solution 8 g/l and hydrochloric acid solution (30%) 2 g/l were fed to the anode chamber. The applied current through the reactor was 4 amperes at 8.5 volts.

[0076] The results of the water composition before and after purification are presented in the following table 1.

TABLE-US-00001 TABLE 1 Result measurement Source Purified Standard Regulatory Indicator water water value Units document Organoleptic indicator Turbidity 2.9 0 ≤2.6 EMF PND F 14.1:2:4.213- 05 Color 4.6 0 ≤20 degree GOST 31868- 2012 Odor 2 0 ≤2 mark GOST P57164-2016 Flavor 0 0 ≤2 mark GOST 3351-74 Generalized indicators pH 7.35 7.5 6.0-9.0 pH units PND F 14.1:2:3:4.121- 97 General 6.38 6.35 ≤7 mg-equ/l GOST 31954- hardness 2012 Permanganate 0.96 0.66 ≤5.0 mg/dm.sup.3 PND F oxidizability 14.1:2:4.154- 99 Dry residue 326 362 Within mg/dm.sup.3 PND F 1000 14.1:2:4.114- 97 Specific 568 607 — μS/cm RD 52.24.495- electrical 2005 conductivity Total alkalinity 6.12 6.28 — mmol/dm.sup.3 GOST 31957- 2012 Free alkalinity 0 0 — mmol/dm.sup.3 GOST 31957- 2012 Cations Ammonium 0 0 2.0 mg/dm.sup.3 FR.1.31.2013. 16570 Iron total 0.49 0 0.3 mg/dm.sup.3 PND F 14.1:2:4.135- 98 Potassium 3.2 3.3 20 mg/dm.sup.3 PND F 14.1:2:4.135- 98 Magnesium 21.6 21.9 — mg/dm.sup.3 PND F 14.1:2:4.135- 98 Manganese 0.038 0 0.1 mg/dm.sup.3 PND F 14.1:2:4.135- 98 Calcium 92 91 — mg/dm.sup.3 PND F 14.1:2:4.135- 98 Anions Hydrocarbonates 373 383 — mg/dm.sup.3 GOST 31957- 2012 Carbonates 0 0 — mg/dm.sup.3 GOST 31957- 2012 Fluorides 0.44 0.58 1.5 mg/dm.sup.3 GOST 31867- 2012 Chlorides 1.1 22.9 350 mg/dm.sup.3 GOST 31867- 2012 Nitrates 0 1.09 45 mg/dm.sup.3 GOST 31867- 2012 Sulphates 9.4 10.6 500 mg/dm.sup.3 GOST 31867- 2012 Microbiological indicators Total Microbial Solid 0 No more The number MUK 4.2.1018- Count TMC growth than 50 of bacteria 01 (mesophilic colonies aerobic and formed in 1 facultative cm.sup.3 aerobic) (CFU/ml) Common Found 0 Absence Number of MUK 4.2.1018- colymorphic bacteria in 01 bacteria 100 cm.sup.3 (colibacillus bacteria group coliforms) Thermotolarent Found 0 Absence Number of MUK 4.2.1018- coliform bacteria bacteria in 01 100 cm.sup.3

Example 5

[0077] The purification process shown in FIG. 1 was used. Water from example 4 was subjected to purification. The conditions for water purification were similar to those described in example 4, except for the water flow rate, which was 200 l/h. An aqueous solution of streptomycin with a concentration of 1*10.sup.−4 mol/l was introduced into the water entering the water purification system at a distance of 20 meters from the entrance to mixer 1 through a 0.5 liter pressurized tank using a dosing pump to create a concentration of antibiotic in processing water ten times greater than the lower limit of sensitivity (2*10.sup.−6 mol/l) of the electrochemical method for analyzing an antibiotic. To determine the initial concentration of streptomycin upstream to mixer 1, a water sample was taken from the sampling port (not shown in FIG. 1) and analyzed for streptomycin content using volt-ampermetric method (see Fedorchuk V. A. Voltamperometric determination of streptomycin and chloramphenicol in drugs and food products. Thesis for the degree of candidate (PhD) of chemical sciences. Tomsk, 2003-[3]). The streptomycin content in the water was in the range of (4.5-5.2)*10.sup.−5 mol/l based on 5 samples analyzed. At the outlet of the water purification system the streptomycin concentration was below the lower sensitivity limit of the method (less than 2*10.sup.−6 mol/l).

[0078] As can be seen from the above results, the use of the present invention allows to increase the degree of water purification and thus increase the efficiency of the process, since the use of the invention virtually eliminates the biofilms accumulation and prevents equipment from biofouling without the need to use additional disinfection stages. The quality of water purification is increased due to the use of a mixture of oxidants.