RS51132B - MICROBIOLOGICAL DISINFECTION OF DRINKING WATER - Google Patents

Abstract

Microbiological disinfectant for drinking water / characterized in that it comprises an electronic current regulator (ERS), which is supplied from a 220V / 50Hz AC power distribution network or a battery (AK) 45 Ah, 12 V, and which through its output terminals is constant a direct current of about 30 mA voltage 6V to 8V variable polarity, feeds a probe (S) housing the silver-based electrodes, and which probe (S) is submerged in water, half the height of the water column, in a well, with a volume reservoir of about 10,000 liters, a drip pool, etc. The application contains 1 more independent and 3 dependent patent claims.

Description

TECHNICAL FIELD

The device for microbiological disinfection of drinking water, according to the invention, belongs to the field of chemical technology and that is to the field of water treatment, more precisely to devices for separating or removing fatty or oily particles or similar floating substances by electrochemical procedures, i.e. electrolysis of water that is treated with electrochemical disinfection, i.e. the device in question for the microbiological disinfection of drinking water is used in the procedures used for the microbiological disinfection of raw drinking water of various degrees of bacteriological malfunction and various characteristics.

Int. Cl.<8>:C 02F 1/467(2010.01)

TECHNICAL PROBLEM

The device for microbiological disinfection of drinking water, according to the invention, solves the problem of realizing the construction of such a device that will be able to carry out microbiological disinfection of large amounts of water of various degrees of bacteriological malfunction and various characteristics based on the use of the bactericidal effect of silver by electrochemical means. Based on this fact that silver, silver ions and some silver salts are extremely strong poisons for microorganisms, and at these concentrations harmless for the human body, an electrochemical device was developed, the construction of which consists of a system of electrodes made of different materials with pronounced and proven bactericidal properties.

The goal of the invention is to realize such a device for microbiological disinfection of drinking water that should have electrodes made of silver as well as electrode types of AgCl, Ag20 and Agi, of which there should be at least two of each type in the device, whereby each of the applied electrode types in the device should be capable of destroying a certain group of bacteria and be selective for precisely defined groups of microorganisms. In addition, certain types of electrodes should be used to extract oxygen, which plays the role of a catalyst in the plasma oxidation process.

STATE OF THE ART

For more than ten years, developed countries have been intensively working on improving drinking water purification technology. This is primarily caused by new knowledge about the effects of various harmful and dangerous substances found in natural waters or formed in water preparation processes, especially with the use of oxidizing agents, above all chlorine.

The danger of using gaseous chlorine in the disinfection of drinking water, which is especially pronounced during its transport and storage, has led large manufacturers of water chlorination equipment (Capital Controls Co.lnc. Colmar, PA, USA, VWallace & Tiernan, Inc., Vineland, NJ, USA, Prominent, Heidelberg, Germany) to develop devices for electrochemical disinfection of drinking water over the last ten years, which would eliminate the disadvantages of using conventional disinfection methods. It should be emphasized that when introducing gaseous chlorine into drinking water using the conventional method, in addition to the mentioned dangers, many diseases can also occur. Namely, medical research confirms that due to the large amount of chlorine in drinking water, the likelihood of developing tumors in the digestive organs increases, compounds that can cause cancerous diseases and mutations are formed with organic matter, and a direct dependence has been established between chlorine and cancer of the colon and bladder.

It is known that silver, even in insignificant concentrations (hundredths of a milligram per liter), has the ability to destroy microorganisms, that is, it has strong bactericidal properties. For example, water that has been standing for some time in silver vessels can then be stored without spoiling for several months because it is sufficiently sterilized even with a very small concentration of silver ions, which were created in it when it came into contact with metallic silver. Some microorganisms die in the presence of 1 part of silver per 100 million parts of water. Such a great toxic effect of silver is explained by the high sensitivity of the cellular plasma of microorganisms to silver ions. It has been proven that these ions (of silver) enter the microbial cell, combine with the protoplasm and destroy it. More details about the aforementioned studies can be found in the professional literature, in the works: 1. P.M.Maltsev, M.V.Zazirnnaya," Tekhnologiya bezalkogo! nyh i slaboalkogolnykh napitkov", Ed. "Pishchevava promvshlennost", Moscow, 1970, p.43. 2. V.Yu.Baklan, V.I.Tregub, V.M.Petrov, N.M.Tkachenko, L.A.Venger, V.F.Hitrich," Elektrokoaguliatsionnya ochistka vod slozhnogo sostava",Khimiva i tekhnologiva vody, 14(1992)316. 3. Henry Bergman, Tatiana Lourtchouk, Kristin Scnoep, 51-th International Society of Electrochemistry Meeting, Book of Abstracts, Krakow, 2000, p.222.

It has also been proven that silver ions are adsorbed on the microbial cell, playing the role of a catalyst in the process of plasma oxidation by air oxygen. The effect of the bactericidal action is already achieved after a relatively short contact, after which the water is disinfected. The lower limit of the bactericidal effect of silver is estimated at a value of 2 x 10"<11>gjona/dm<3>, which is also presented in the literature, i.e. in the articles: 3. Henry Bergman, Tatiana Lourtchouk, Kristin Schoep, 51-th International Society of Electrochemistn/Meeting, Book of Abstracts, Krakow, 2000, p.222.

4. P. Whiteway," Pure water\15(1999)10.

5. M.G. Pavlović, M. M. Pantić, X International Symposium in the Field of Cellulose, Paper, Packaging and Graphics, Proceedings, Zlatibor, June 2004, pp. 163-166.

Accumulation of silver ions in water is all the faster if the larger surface area of the metal is in contact with the water. The goal is therefore, on the one hand, to maximize this area with the least consumption of metal. On the other hand, an autonomous electronic device should be made that will be able to communicate a predetermined current (in constant or programmed mode) to such a system of electrodes, and thus always maintain the required (minimum) amount of silver ions in the system, which is required for microbiological disinfection of water. It should be noted that a faster and more convenient way to obtain silver water is the contact of water with silver chloride and not with metallic silver. For this reason, a silver chloride electrode was placed in the electrode system, which is located in the device for microbiological disinfection. The Ag<+> concentration obtained with a saturated solution of this salt is about 10"<5>mol/dm<3>.

DESCRIPTION OF THE INVENTION

* Solving the previously defined technical problem, the authors imagined a device for microbiological disinfection of drinking water that has six electrodes made of silver as well as electrodes of AgCl, Ag20 and Agi, of which there are two of each type in the device. Each of the electrode types used in the device is capable of destroying a specific group of bacteria and is selective for precisely defined groups of microorganisms. In addition, on certain types of electrodes, oxygen extraction is ensured, which plays the role of a catalyst in the plasma oxidation process.

The following reactions in the system are possible:

In addition to the above-mentioned reactions, a combination of:

The process takes place on that electrode:

Or, if the environment of the electrode is saturated with AgCl, the resulting silver ions will be leached very quickly from the solution in the form of AgCl, so the above reaction can actually be represented by the formula:

The solubility of AgCl is very low and constant, so at 25 °C the ionic solubility product is:

so for the potential of that electrode we get:

E° = EAg+ RT/F In LAgci = 0.798 ± 0.059 log (1.8 x 10"10) = 0.222 V - The Ag/AgCI electrode can therefore be considered a chlorine electrode with a very low dissolution pressure, i.e. a certain amount of chlorine is always present in the water.

As a conclusion, it can be said that the separation of silver, hydrogen and oxygen reduction can occur at the cathode, while the separation of oxygen and chlorine can occur at the anode.

The details of the device for microbiological disinfection of drinking water, according to the present invention, will be presented on the example of execution and the attached drawings, in which the same reference numbers will denote the same elements and where: Figure 1 shows the cross-section of the probe of the device for microbiological disinfection of water for

a drink according to the present invention;

Figure 2 shows a cross-section of the probe electrode system of the microbiological device

water disinfection, according to this invention;

Figure 3 shows the block diagram of the connection of the electronic current regulator with the probe of the device for microbiological disinfection of water according to the invention;

Figure 4 shows a schematic representation of the pulse shape of the constant current of variable polarity used in the device;

Figure 5 shows the block diagram and connections of the circuits that make up the electronic current regulator

this invention;

Figure 6 shows the block diagram of the placement of the probe of the microbiological water disinfection device during application, where we see the positions to which the probe of the microbiological water disinfection device is placed when the probe is placed:

a) in a well; b) in the tank and c) in the pool.

Figure 7 shows a photograph of the appearance of the realized solution of a probe that is immersed in a well,

tank or pool with water to be microbiologically disinfected.

The device for microbiological disinfection of drinking water, according to this invention, includes an electronic regulatorER current with connections AC to the electrical distribution network of alternating voltage 220V/50Hz or DC to a source of direct current (e.g. battery) of voltage 12V, the output of which is connected by a cable to a submersible probe with electrodes that form silver ions and thus performing microbiological disinfection of the water being purified, in which the probe is immersed.

Figure 1 shows a cross-section of the probe assembly of the device for microbiological disinfection of drinking water, according to the present invention, in which a specially shaped cylindrical shaft 1 (support) of the probe made of hard plastic (e.g. ABS) is visible, on which an introducer 2 is placed on the upper side, which is threadedly connected to the upper holder 3, and which is threadedly fixed via nuts 4 and 5 to the upper electrode 6, on which the upper side attached connection 7 Below the upper electrode 6 along shaft 1 are alternately arranged silver electrodes 6 separated by spacers 8 from meshes 9 that are placed between the electrodes 6, whereby in the probe S of the device there should be two meshes 9 of each type, and six silver electrodes 6. On the bottom side, the last electrode 6 has a connection 12 attached, while on the bottom side it is fixed with a nut 10, which is tightened with a spacer 11 and a screw-fixed lower holder 13 with a roller reinforcement 14 with a larger diameter than the diameter of the roller shaft 1.

It can be seen from Figure 2 that in the electrode system of the subject probe, in addition to the silver electrode, there are also other electrode types such as AgXi, AgX2 and AgX3, where Xi=CI, X2=l, and X3=0. The surface of each electrode should be at least 0.5 dm<2>. The electrodes are obtained by a process in which a 75-100 pm thick silver coating is electrochemically applied to a 0.2 mm thick wire mesh, with a mesh opening of 0.5 mm, a surface area of 0.5 dm<2>, at a current density of 0.5 A/dm<2>, at a temperature of 25-30 °C, and the electrolyte is prepared by dissolving alkaline cyanide in half the required volume of water, then silver cyanide is then dissolved and finally the necessary alkali, the solution is filtered and topped up with water, preferably distilled water, to the required volume, where the composition of the electrolyte for obtaining a silver coating is:

Anodes should be made of pure silver and placed in anode bags, and the electrolyte should be constantly filtered, so that it does not contain solid particles.

The most resistant to bactericidal action are intestinal bacilli (fecal bacteria). Therefore, in the system of devices for microbiological disinfection of water, according to the invention, electrodes made of other silver salts are incorporated, which provide a faster and more convenient way to destroy both vegetative and sporophytic forms of bacteria. In this way, each of the applied types of electrodes in the device is capable of destroying a specific group of bacteria and is selective for precisely defined groups of microorganisms.

Figure 3 shows the block diagram of the connection of the ERScurrent electronic regulator with the device for microbiological disinfection of drinking water. The ERS current electronic regulator is powered via a connection from the standard 220 V alternating current 50 Hz electrical distribution network, and it is also possible to power it from a 12 V DC battery or from another 12 V DC source (e.g. solar cells or the like). The probe S of the device for microbiological disinfection of drinking water is connected to the output of the electronic current regulator ERS, which is fed with direct current of voltage 6 to 8 V with a strength of 30 mA, and which is immersed in the tank R with the water being purified.

Figure 4 shows a schematic representation of the waveform of a constant direct current of variable polarity, which is supplied to the probe electrodes of the device for microbiological disinfection of water according to the present invention. The electronic device, which should provide a constant direct current of 30 mA, the polarity of which changes alternately, is enclosed in a plastic box with a direct connection to the 220 V/50 Hz electrical distribution network. The polarity of the pulse is changed alternately, approximately 15 min in a period of 180 min (±10%), followed by a break of 180 min and so alternately. Therefore, the electronic part of the device works according to the on/off system, because it is unnecessary for the device to work 24 hours a day. When a certain amount of silver ions is extracted, the device turns off and after a relaxation period turns on autonomously. There are two pairs of terminals on the printed circuit board, one pair for connecting electrodes, and the other for powering from an additional battery, if there is no source of 220V/50Hz at the place of application.

Figure 5 shows a detailed block diagram of an autonomous device (electronic current regulator ERS shown in Figure 3), which provides a constant direct current whose polarity changes alternately. There are four functional circuits inside the ERScurrent electronic regulator, namely: 1. AC/DC circuit is a rectifier that converts the mains voltage 220V/50Hz alternating current (AC) into direct current (DC) voltage 12V; 2. the EPSS circuit is an electronic switch and current stabilizer that maintains a constant current of 30 mA through the electrodes of the device and alternately switches the electrodes on/off at intervals of about 3 hours; 3. the EPP circuit is an electronic polarity switch that changes the polarity of the voltage on the electrodes in periods lasting about 4 minutes; and the 4th KEL circuit is a control electronic logic - ie. timing circuits-timers that control the on/off times of other blocks.

The ERS current electronic regulator is housed in a plastic box that has a built-in plug for connection to the city's electrical distribution network with a voltage of 220V/50Hz, so if we have available voltage from the network, it is enough to just plug the plug-box into the city network's socket.

If the power supply from the 220V/50Hz city network is not used, a 12 V car battery can be connected to the sockets inside the box, as a backup power source, or some other DC power source, for example: solar cells, or si.

The device is secured against incorrect connection to the battery terminals, and it is also protected against short circuit. The ambient operating temperature range is from 0 °C to +75 °C. The autonomy of the device connected to the 45 Ah battery is 3 months. The printed circuit board is protected on high-quality vitroplast on the side where the connections of the elements are soldered with a protective green stop varnish, and on the side of the elements marked with inscriptions in white. The LED indication indicates that the device is switched on, that is, that the electrodes are in an active state. The current regulator does not contain electromechanical components.

Protective grounding is not required for the operation of the device. Protection against electric shock is performed by installing the ERS current electronic regulator in a plastic box that has no metal contact parts, so any room socket of the city's electricity distribution network can be used.

If there is no city network near the place where water disinfection is carried out, the device can be connected to a 45AH/12V car battery. In this case, the battery is connected to the current regulator with an additional cable that is connected to the DC connectors inside the ERS regulator, to the contacts marked +

BATTERY - .

The probe with the electrodes is connected by a cable to the output connections in the regulator box when the device is delivered.

Figure 6 shows a diagram of the position of the device (probe) that is immersed in a well (6a), in a tank (6b), in a pool (6c) and so on. It can be seen from Figure 6 that the body of the probe should be immersed in the water so that it is placed at half the height of the water column. Due to the light weight of the probe (cea 230 g), no special rope is needed, but the probe hangs on its own cable for powering the electrodes.

The device for microbiological disinfection of water, according to this invention, was certified by the City Institute for Health Protection~Service for Hygiene and Medical Ecology in Belgrade, which issued an "Opinion on the effectiveness of devices for microbiological water disinfection" (attached in the subject of the application), and the Clinical Center of Serbia, Institute of Occupational Medicine and Radiological Protection "Dr. Dragomir Karajović", (Center for Protection against Ionizing and Non-Ionizing Radiation), gave based on measurements expert opinion on the toxicological effect of this device that this device may possibly produce.

The results of testing the microbiological properties of the well-type water supply system, treated with the device for microbiological water disinfection according to the invention, and after expert review, show that it is possible to completely carry out the microbiological disinfection of natural waters with the device in question, namely water containing bacteria such as: Esherichia coli, Citrobacter (F), Enterobacter (F), Bacillus Aeromonas, Streptococcus (F), Sulfite-reducing clostridium, Pseudomonas aeruginisa, Bacillus saprophyte and Acinetobacter. It was also established that the device can be used in water supply systems of sources, catchments, reservoirs, pools, etc. (Certificate - opinion of the Clinical Center of Serbia can be found in the attachment of the documentation), and in the attachment there is also the "Certificate of Applied Occupational Safety Measures" on the device in question issued by JSC Occupational Safety and Environmental Protection "Belgrade".

easily the device for microbiological disinfection of drinking water, described with reference to a specific embodiment shown in the drawings, it is clear that the details of the construction and other individual embodiments, as well as individual stages of the microbiological disinfection of drinking water can be changed in relation to those described and shown in the drawings, without thereby deviating from the idea of the subject invention as defined in the following requirements.

Claims (5)

1. A device for microbiological disinfection of drinking water, indicated to include an electronic current regulator (ERS), which is powered from the electrical distribution network with an alternating voltage of 220V/50Hz or a battery (AK) 45 Ah, 12 V, and which through its output connections with a constant direct current of about 30 mA of voltage of 6V to 8V of variable polarity, supplies the probe (S) in which the electrodes are placed on the base of silver, and which probe (S) is submerged in water, to half the height of the water column, in a well, a tank with a volume of about 10,000 liters, a captan pool, etc. 2. Device for microbiological disinfection of drinking water, according to patent claim 1, indicating that the alternating voltage 220V/50Hz of the electronic current regulator (ERS) is supplied to the input connections of the rectifier (AC/DC), from the output of which the direct current voltage 12V is supplied to the input of the electronic switch and current stabilizer (EPSS), which can alternatively be supplied with direct current from the connected 45AH/12V battery to the other input contacts marked with + BATTERY -, where the electronic switch and current stabilizer (EPSS) leads a constant current of 30 mA from its output to the input of the electronic polarity switch (EPP) from whose output the electrodes of the probe (S) are fed with a direct current of 30mA of voltage 6V to 8V, where both the electronic switch and current stabilizer (EPSS) and the electronic polarity switch (EPP) are connected to the control circuits of the control electronic logic (KEL). 3. Device for microbiological disinfection of drinking water, according to the previous requirements, indicated that the probe (S) is designed so that on the upper side of the probe support (S) there is a shaped roller shaft (1), made of hard plastic, e.g. made of ABS, an insert (2) is threadedly connected to the upper holder (3), and which are screw-fastened via nuts (4) and (5) to the upper electrode (6) on which the connection (7) is attached from the upper side and where below the upper electrode (6) along the shaft (1) alternately arranged electrodes (6) made of silver, separated by spacers (8) from the meshes (9) placed between the electrodes 6, where in the probes (S) of the device should have two meshes (9) of each type, and six electrodes (6) made of silver, and where a connection (12) is attached to the bottom of the last electrode (6), while the electrode (6) is fixed with a nut (10) which is tightened with a spacer (11) and a threaded lower holder (13) with a roller reinforcement (14) with a larger diameter than the diameter of the roller shaft (1) and where they are in the system electrode, in addition to electrode (6) made of silver, there are also other electrode types such as AgXi, AgX2 and AgX3, where X1=Ci, X2=1, and X3=0, and where the surface of each electrode is at least 0.5 dm<2>. 4. Device for microbiological disinfection of drinking water, according to the previous requirements, indicated by the fact that the electrodes are obtained by a process in which a silver coating of thickness 75-100 pm is applied electrochemically to a copper mesh made of wire 0.2 mm thick, with a mesh opening of 0.5 mm, surface 0.5 dm<2>, at a current density of 0.5 A/dm<2>, at a temperature of 25-30 °C, and that the electrolyte is made by dissolving alkaline cyanide in half of the required volume of water, then dissolving silver cyanide and finally the necessary alkali, filtering the solution and adding water, preferably distilled water, to the required volume, where the composition of the electrolyte for obtaining silver coatings is: where the anodes should be made of pure silver and placed in anode bags, and the electrolyte should be constantly filtered, so that it does not contain solid particles, and which are used to prepare the surface of the mesh (9) standard commercial solutions as well as for the application of electrochemical coatings of AgCl, Ag20 and Agi, and that the salt and silver oxide coatings should be 40-50 pm thick, and applied at a current density of 0.3 A/dm<2>, at a temperature of 25-30 °C. 5. The procedure for the microbiological disinfection of drinking water, contaminated with bacterial cultures such as: Esherichia coli, Citrobacter (F), Enterobacter (F), Bacillus Aeromonas, Streptococcus (F), Sulfite-reducing clostridium, Pseudomonas aeruginisa, Bacillus saprophyte and Acinetobacter, and using the device according to the previous patent claims is indicated by connecting the electronic current regulator (ERS) to an alternating voltage of 220V/50Hz or alternatively to a battery (AK) 45 Ah, 12 V, probe electrodes (S) immersed in a well with water, a tank with water or a catchment pool with water, supply a direct current of 30mA voltage 6V to 8V, the polarity of which alternately changes every 4 min in a period of 180 min (±10%), followed by a break of 180 min, then turning on the device again and alternating polarity in a period of 180 min during which the electrodes probes (S) release silver ions.