HYPOCHLORITE

FIELD OF THE INVENTION

This invention is related to the field of disinfectant generators, and in particular, the invention relates to a water-based disinfectant generator powered with a USB connector and the method to produce said disinfectant.

BACKGROUND

With the development of industrial society and the increase in the World’s population, the environment and water resources have been increasingly polluted with pathogenic microorganisms and organic compounds. Affordable, portable, and functional devices are required to attend society’s present needs.

There are many methods available to treat and purify water. Most of those treatments rely on the introduction and maintenance -for a certain period of time- of a disinfecting agent into the water in order to at least partially eliminate biological and chemical contamination from said water.

There are many disinfectants capable of being used to treat and purify water, and to disinfect objects or surfaces in general. Among those disinfectants, chlorine can be mentioned, either in the form of gas or hypochlorite, or substitutes thereof, such as chloramines, ozone, hydrogen peroxide, peracetic acid, chlorine dioxide. These compounds produce oxidation to effect the deactivation of biological organisms and the destruction of other organic compounds present in the water or on surfaces to be treated.

Chlorine, in the form of gas or hypochlorite, is one of the most popular, widespread, affordable and well known compounds used to treat and purify water.

The sodium hypochlorite production process uses salt and water as its principal elements. The production process is based on the following chemical reaction:

NaCl + ¾0 NaClO + H ₂

enabled by electric current. Thus when the electrolyte concentration reaches a certain hypochlorite concentration it is considered useful and has a strong sterilizing effect. The above-mentioned process takes place following successive and simultaneous steps. In a first step, water is reduced on the surface of a cathode to form hydrogen and hydroxide ion, following

2¾0 + 2e 20H + H ₂ .

Hydrogen (H ₂ ) is highly-insoluble in reaction medium at all practical expected operating conditions (k° _H = 0.00078 mol/kg-bar), and thus evolves as fine bubbles which are eliminated from the reaction medium. Hydroxide ions (OH ), on the other hand, stay dissolved in the reaction medium. Chloride ions (Cf) are simultaneously oxidized on the surface of an anode to form chlorine (Cl ₂ )

2C1 Cl ₂ + 2e .

Chlorine is relatively soluble in water at expected operating conditions (k° _H = 0.095 mol/kg- bar). The chlorine and hydroxide ion thus formed further react to form hypochlorous acid and chloride, following

Cl ₂ + OH HClO + cr.

Hypochlorous acid readily dissociates at the prevailing pH of about 8 to 13 into hypochlorite

HClO + OH C10 + H ₂ 0.

In the particular case where the source of chloride ions is sodium chloride, hypochlorite solutions may alternatively be written as containing its respective sodium salt NaClO.

Competing reactions include the anodic oxidation of water on the surface of the anode to form nascent oxygen (0 ₂ )

2H ₂ 0 0 ₂ + 4H + 4e ,

and the formation of related and higher oxides thereof, possibly also including ozone (0 ₃ ) and in general an unspecified mixture of oxides for which no attempt at describing their reaction mechanism is made in this application. Further competing reactions include the further oxidation of hypochlorite into higher-oxides of chlorine element, for example into chlorate following

ClO + 0 ₂ ClOT,

or the parasitic cathodic reduction of hypochlorite or hypochlorous acid to chloride following

HClO + 2e Cf + OH . Some competing reactions, such as the formation of various oxides of water or oxygen element may aid in the disinfecting activity of the obtained product. Other competing reactions, such as the reduction of the formed hypochlorous acid or hypochlorite, reduce the efficiency of the cell. Other competing reactions, such as the formation of chlorates (CIO ₃ ) not only reduce the efficiency of the cell but also can produce toxic compounds. The spontaneity, extent, and rate of reactions in general, and of competing reactions in particular, is in general a function of temperature, cell voltage, electrode choice, electrode separation, mixing effects, light (particularly UV), time elapsed, concentration of each species, and activity coefficients in the reaction medium. In order to maximize the formation of pure hypochlorite and to reduce the formation of undesired species and the extent of competing reactions, above-mentioned variables must be carefully selected and controlled by the proper design of the device and operation. Since electric current is the measure of the charge flow per unit time, and the electrochemical production of chlorine and hydroxide (and thus hypochlorite) is dependent on charge flow, it follows that the rate of production of hypochlorite is positively correlated with current. In particular and as depicted above, the production of one mole of hydroxide requires the flow of one mole of electrons, while the production of one mole of chlorine requires the flow of two moles of electrons. The charge of one mole of electrons is approximately 96,485 coulombs according to the Faraday constant.

Chlorination is the process of adding chlorine to water in order to disinfect it through the oxidation of substances disseminated in the water and by eliminating pathogenic bacteria, germs and viruses present in it. Chlorine is available as compressed elemental gas, sodium hypochlorite solution (NaOCl) or solid calcium hypochlorite (Ca(OCl)2). Chlorination is not only a method to treat and purify water but in general also a method to disinfect and kill germs and viruses present on the surfaces of raw vegetables and fruits, on food, tableware, sanitary ware, furniture, etc. thus helping to prevent dysentery, influenza, hepatitis and the spread of other diseases. Moreover, sodium hypochlorite as a disinfectant is used to treat dermatitis, athlete’s foot, nail infections and some gynecological inflammations.

CN205295492 teaches that sodium hypochlorite disinfecting agents have the disadvantage of not being chemically stable, meaning that said sodium hypochlorite easily decomposes when exposed to heat, light, or to certain metallic impurities, thus rendering the long-term storage inconvenient and consequently making it lose its disinfecting efficacy. In effect, in household use, the amount of sodium hypochlorite used each time is usually relatively small, so that the rest of the disinfecting agent (i.e. that which is not used and left in the bottle) must be kept stored for its later use. In order to prolong the shelf-life of commercial sodium hypochlorite solutions, bottled or barreled products with chemical additives and stabilizers, usually being unspecified chelating agents or even functionalized organic or aromatic compounds, are usually available in the market. All the raw materials are processed in a centralized chemical plant. After said certain chemical stabilizer is added and the solution is stored in an opaque bottle or barrel, the sodium hypochlorite disinfectant could in principle be stored for several months. However, said additives and stabilizers could pollute the environment or render the sodium hypochlorite unsafe for treating elements exposed to foods or for disinfecting water for human consumption. Moreover, pollution can be caused by the bottle packaging or the barrel themselves, and also by the transportation. In addition, and due to the fact that sodium hypochlorite disinfectant is a strong oxidizing agent, sodium hypochlorite is classified as a dangerous good for transportation, storage and handling. Moreover, it is considered hazardous in case of skin or eye contact, or ingestion. Thus, it should be kept out of the reach of children or pets.

Other difficulties belong to the logistic and storage nature of a bottle of sodium hypochlorite required to treat water or disinfect objects. In modem cities, sodium hypochlorite is not frequently available at drugstores, pharmacies or small markets, thus making it necessary to travel to a supermarket or other large stores to acquire sodium hypochlorite. This could cause a waste of time to people who are discouraged from buying the product. In addition, markets often sell relatively large bottles of sodium hypochlorite making the storage of these bottles less attractive for people who live in small apartments or micro-apartments in modem cities and who only require from 1 to 3 drops of sodium hypochlorite a time to treat and purify water or to disinfect raw vegetables and fruits.

The potential hazards caused by the storage (e.g. by having large amounts of corrosive liquids at home), the handling of sodium hypochlorite (e.g. by inadvertently bleaching one’s clothes), and also the burden and pollution associated with its storage (e.g. as a hazardous substance), distribution (e.g. forcing the usage of plastic bottles), production (e.g. by releasing mercury to the environment in the mercury-cell chlor-alkali process), and transportation (e.g. by burning fossil fuels), are serious problems that require an all-encompassing and technically sound solution. The first problems, i.e. those inherent to its corrosive nature, have received widespread attention as of recently in mass-media following so-called“bleach attacks”, thus calling for the restriction of large, bottled quantities of bleaching agents. Those problems associated to the release of mercury have received attention several years ago following the large-scale release in the Minamata disaster, but have been silent lately even though small amounts of mercury are still continuously released to the environment. The pollution associated with plastic bottles and transportation is progressively receiving more attention. Some partial and indirect attempts at addressing these problems have been discussed in the related art.

Description of the Related Art:

The prior art shows many devices to treat and purify water including a UV sterilizer, sodium hypochlorite generator and different types of electrolytic sterilizer apparatus.

CN 204625798 teaches a sodium hypochlorite disinfectant generator. While the hypochlorite disinfectant produced by the generator is satisfactory for its intended usage, the structure of the generator is considered constructively complex as it comprises a kettle body, an electric appliance bin and an electrode, an electrode fixing cover, an electrode wire, an electrode plug, an electrode socket and a rectification conversion device. The equipment cannot satisfactorily operate due to the numerous technological or quality problems arising during its usage. In addition, it is said that, due to the many parts of the generator, it becomes too large in size and is not suitable for being carried around or easily stored. Another serious limitation of the generator is that an external 220 V power supply needs to be available for the equipment to be used, so that the equipment can not be used in activities such as outdoors, field traveling and the like.

CN 205295492 aims to solve the problem of complexity and external power supply of patent CN 204625798 by providing a simpler structure and a smaller sized generator powered by means of a USB connector in an attempt to solve the above-mentioned problems. However, the proposed device is considered overly elementary. One of the biggest defects of this patent, one that renders it virtually useless, is represented by the fact that it presents no means for protecting the electrodes from mechanical damage. Another defect that can be mentioned is that, at the prevailing conditions and configuration, the reaction favors the production of undesired and potentially harmful chlorates, thereby reducing the current efficiency and also greatly reducing the electrode life-time. Also as described, by separating the electrodes by means of an insulating material the production rate is greatly diminished.

Another sterilizing device described in the prior art for treating and purifying water is provided by US Patent Application No. 20150021243A1. This personal water purifier consists of an electrolytic device and method for generating a disinfecting solution that utilizes a brine generator, an electrical circuit with an on-board solar panel, and a rechargeable storage battery. However this purifier does not meet the desirable features of an adequate personal purifier since the proposed means of powering the device through solar means is deemed insufficient when compared to the power required for a useful usage. While the device may be left in the sun for it to charge, sunlight may not be available when required. Moreover, incorporating an inner reaction cell, a“water finder”, and said solar panel and rechargeable batteries to the device is cumbersome for most massive consumer applications.

Yet another device provided in the prior art by CN204643905 consist of a sterilizing device that uses UV to eliminate the bacteria, germs and biological contamination. However, sterilization through UV is only able to eliminate bacteria and biological contamination immediately surrounding the surface of the device but is not able to eliminate bacteria behind the shadow of particulate matter or in distant regions of a vessel. In particular, UV has no residual effect and UV lamps are expensive to replace and the precise model required may not be available.

Thus, the sterilizing and hypochlorite-generating devices designed or proposed to date are inadequate to provide an efficient portable device, small in size, affordable, user-friendly and that overcome the limiting requirements in external sources of power.

SUMMARY

The objective of this invention is to provide a simple, user-friendly and affordable portable device to generate hypochlorite for general use or purify small quantities of water that is powered by use of, e.g., a USB connector to solve the problem of complex external power supply and a method to produce hypochlorite using said device.

In a first embodiment, the hypochlorite-producing device of the present invention comprises a plastic body, at least a pair of electrodes, a voltage regulator with a current limiting circuit, a timer, a light-emitting diode, a power plug, and a plastic anchor or hook.

For example, the body is of dimensions of about 30 mm x 120 mm x 10 mm, with a narrow, slitted, plastic housing for the electrodes less than 19 mm in diameter and comprising staggered frontal-lateral slits that favor the natural convective flow of the reaction medium, said plastic being of a high-grade polymer, preferably Nylon-6,6. The anode is a grade 1 or 2 titanium strip with a mixed-metal oxides coating, preferably of ruthenium and iridium oxides. For example, the cathode is a grade 1 or 2 titanium strip, either coated or not, or of nickel or stainless steel. The pair of electrodes may be positioned side-by-side or facing each other, e.g., side-by-side. The voltage regulator sets the operating voltage between the electrodes at a range of 2.1 to 4.8 V, or 5.3 to 6.5 V, preferably at a range of 2.8 to 3.5 V.

The maximum current is limited for safety reasons to up to 2,000 mA or more, preferably to a range of 600 to 1,000 mA. The timer ensures that the device stops working if left unattended after a specified period of time, preferably in a range of 30 to 90 minutes. The light-emitting diode signals that the device is either working or ready to work, or in standby, preferably by blinking and staying on, respectively. The power plug serves to power the device using an external power source, the plug preferably being a standard USB port. The plastic anchor serves to hang the device from the power cable so that it may be employed by hanging the device from the side of a bucket.

In a first embodiment, the method comprises the step of reacting naturally-occurring chloride ions in water to form hypochlorite by connecting the device to a power source, introducing the part of the device that contents the electrodes into said water, and allowing sufficient time for the hypochlorite to reach a useful concentration for the desired purpose. Said time preferably in a range of 1 to 15 minutes and more preferably at a range of 5 to 7 minutes. The overall reaction taking place is, as described above,

NaCl + H ₂ 0 NaClO + H ₂ ,

the electrochemical steps undergoing over the surface of anode and cathode, and the formation of hypochlorite undergoing in the bulk of the solution. After said certain period of time, the user removes the device from its position and obtains a solution enriched in hypochlorite and ready for its use. In one aspect, there is no insert, baffle, or any other separation element between the anode and the cathode. In other aspect, the anode and the cathode are solid.

In another embodiment, the method comprises the initial step of adding a source of chloride ions to the water, preferably sodium chloride in the form of granular table salt, so that the concentration of chloride ions in the solution is increased thus enabling the production of higher concentrations of hypochlorite or hypochlorous acid than would otherwise be attainable. The reaction time is preferably in the range of 30 seconds to 15 minutes and more preferably at a range of 5 to 10 minutes. The rate of production is increased by the addition of said source of chloride ions by increasing the concentration of available chloride ions and the conductivity of the solution and thus the electrolytic current. The overall reaction taking place is, as described above,

NaCl + H ₂ 0 NaClO + H ₂ ,

with the electrochemical steps undergoing over the surface of anode and cathode, and the formation of hypochlorite undergoing in the bulk of the solution. If the solution is completely devoid of chloride ions, its conductivity may be so low that no reaction takes place. After said certain period of time, the user removes the device from its position and obtains a solution enriched in hypochlorite and ready for its use. In one aspect, there is no insert, baffle or any other separation element between the anode and the cathode. In other aspect, the anode and the cathode are solid.

In another embodiment, the method comprises a step of tying the power cable around or through the plastic anchor, and hanging the device from a higher point before introducing the part of the device containing the electrodes into the water. In one aspect, there is no insert, baffle, or any other separation element between the anode and the cathode. In other aspect, the anode and the cathode are solid, e.g., the anode and/or cathode are not a film.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated into and form a part of the specification, illustrate several embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are only for the purpose of illustrating a preferred embodiment of the invention and are not to be construed as limiting the invention. In the drawings:

FIG. 1 is an exploded view of a preferred embodiment of the sodium hypochlorite generator according to the present invention.

FIG. 2 is a representative chart of the electronic circuit according to the present invention. FIG. 3 is a representative view of a preferred embodiment of the anchor according to the present invention.

FIG. 4 is a representative view of the preferred embodiment immersed in a shallow vessel. FIG. 5 is a side view of the preferred embodiment presenting hook 21.

FIG. 6 is a plot of initial current versus voltage of example 1. DETAILED DESCRIPTION

In the example embodiment of the present invention shown in FIG. 1, the disinfection device comprises a body 1, a pair of electrodes (anode 2a and cathode 3a), an electronic circuit and printed circuit board 4 comprising timer 5 a, USB port 6a, voltage-regulator 7a and regulator circuit 20 of FIG. 2 comprising a current-limiting circuit, and LED 8a and its control circuit 9 of FIG. 2, a pair of electrically conducting pads 10, for example coated with nickel, gold, or similar material, in which each electrode electrically contacts separately, i.e. without electrically short-circuiting between anode 2a and cathode 3a, the electronic circuit 4, and a plastic anchor 19 of FIG. 3 or hook 21 of FIG. 5. Body 1 can further comprise an attached clip or hook 21 of FIG. 5 reminiscent of that present in the cap of some pens so that the device may hang for example from a pocket or from the side of a vessel. Body 1 can further comprise at least one through-hole 22 so that for example a string 23 or a keyring may be threaded through it as in FIG. 5. Body 1 can further comprise inner segmentations 11 to hermetically seal its orifices, in particular where an electrode such as 2a or 3a or a USB port such as 6a is placed. Body 1 can also comprise pins 12 or other pressing element to keep an electrode such as 2a or 3a in its place and to effect mechanical pressure to achieve electrical contact between each pad 10 on the electronic circuit 4 and said electrode 2a or 3a. Pins 12 or pressing elements can further be placed at the lower end 15 of the electrode or at mid-length 16 or closer to the upper end 17. Body 1 comprises horizontal 13 and/or vertical 14 slits or in general some orifices, which are not necessarily horizontal nor vertical, on some or all sides of body 1, to allow the generated hypochlorite to flow out of the device while fresh water and chloride ions flow in. The design of body 1 and slits 13, 14 favor the natural convective flow of the mixture by allowing bubbles to rise and drag liquid alongside. An orifice 18 may further be included in the bottom of body 1 thus allowing the liquid mixture to drain when the device is removed from the medium. Body 1 is preferably of a high-grade polymer, such as Nylon-6,6. Body 1 also functions to mechanically protect electrodes 2a, 3a from scratching or damage such as in case of falling or bending during handling, or contacting abrasive or sharp objects. In the present invention, insulation is achieved by leaving a gap between the electrodes so that they do not contact each other, said gap allowing the passage of air, aqueous solution, or bubbles, and not by a physical insulating material such as a spacer, insert, baffle, or any other structural separation element.

In another embodiment, body 1, enclosing the electrodes, can be narrow enough to fit through the necks of commonly employed bottles, such as a PET bottle, which are usually nominally 19 to 24 mm in diameter, so that the user may employ the device to generate variable amounts of hypochlorite inside said bottle without requiring a special flask or vessel. Body 1 is optionally configured to sizes smaller or larger depending on a variety of features, such as, the size and/or design of the neck or other parts of bottles or vessels or containers.

Body 1 in general serves to contain, enclose, and protect inner elements from physical damage while preserving the desired functionality, i.e. electrochemical activity. The device is powered with a USB port 6a which feeds continuous current to a voltage-regulator 7a which feeds continuous, oscillating, reversing or otherwise pulsed current, preferably continuous, according to regulator circuit 20 of FIG. 2 which sets said voltage between anode 2a and cathode 3a. Timer 5a of FIG. 1 serves principally to cut the current from flowing between the electrodes and through the reaction medium and thus stop all electrochemical activity. If the electrolytic apparatus were left unattended and without a timer, unknown amounts of chlorine may form and, upon saturating the solution, may evolve as heavy chlorine gas which is irritating, toxic, and at least not directly the intended product. Timer 5a may be tunable so that its cutting-time may be tuned for example with buttons or dials by the user so that it serves additionally to automatize and simplify the usage. When the device is powered and before the timer has cut the current, hypochlorite can begin to be generated readily upon immersing the part of the device containing anode and cathode first into a chloride-containing aqueous solution.

Electrodes 2a, 3a are made of metallic strips, preferably cold-formed and punctured to their preferred shape according to body 1 and mechanical design. Anode 2a is of grade 1 or 2 titanium with a mixed-metal oxides coating, preferably of ruthenium and iridium oxides. Cathode 3a is of grade 1 or 2 titanium, either coated or not with said mixed-metal oxides, or of nickel or stainless steel. Under most configurations it is generally immaterial the relative positioning of anode and cathode with respect to each other, i.e. cathode and anode may be swapped with respect to the positioning of FIG. 1. However, certain advantages may be obtained stemming from innovative configurations, such as for example if a cathode, which in general more actively evolves bubbles, is placed below an anode so that the upwards buoyant stream of fine hydrogen bubbles (a) rapidly removes chlorine-rich solution from the surface of said anode increasing the reaction rate, (b) the undesired cathodic rate of reduction of hypochlorite or hypochlorous acid into chloride is reduced by at least partially avoiding freshly generated hypochlorite or hypochlorous acid from being reduced on the surface of cathode and instead being dragged into the bulk of the solution. The pair of electrodes may be positioned side-by-side or facing each other, preferably side-by-side. The separation between the electrodes when placed side-by-side is in the range of 1 to 5 mm, and of 1 mm in the case shown in FIG. 1. Thus, a higher generation velocity can be achieved for some given initial chloride concentration in water. The separation between the electrodes when placed facing each other is in the range of 1 to 10 mm, preferably about 2 mm. Anodes and cathodes are not to electrically contact each other or otherwise a short-circuit could occur, thus partially or completely eliminating the desired electrochemical activity. Anode 2a may be wider than cathode 3a if parasitic reduction of hypochlorite is suspected or measured. The length of the electrodes is in the range of 5 to 16 cm. The mixed-metal oxides coating at least anode 2a and also possibly cathode 3a is either difficult or impossible to solder by industrially standard methods on copper or gold-plated pads 10 commonly found on electronic circuit boards such as 4. In the present invention electrodes 2a, 3 a are electrically contacted to electronic circuit 4 by at least one of the following methods: (a) pressing each electrode to its pad with pin or pins found in body 1, (b) pressing as in (a) while having slightly deformed each electrode away from its flat conformation so that the contact is improved, (c) pressing as in (a) or (b) while adding a conductive adhesive so that both the contact and the mechanical resistance are improved, (d) with a rivet or a similar mechanical element, (e) pressing as in (a), (b), or (c) while having first removed the oxides coating from each electrode by mechanical or chemical methods so that the contact is improved, (f) with a rivet, screw, nut and bolt, or similar mechanical elements wherein said mechanical elements press together front and back sides of body 1, and electronic circuit and board 4 and electrode 2a or 3a.

Electronic circuit 4 is diagrammatically outlined in FIG. 2. Voltage regulator 7b sets the operating voltage between the electrodes at a range of 2.1 to 5.0 V, preferably at a range of 2.1 to 4.8 V, or 5.3 to 6.5 V, preferably at a range of 2.8 to 3.5 V. The formation of chlorates is reduced in this range and thus the electrochemical efficiency is increased while preventing the formation of undesired and potentially harmful products. Voltage regulator 7a and 7b can also encompass a current limiter, so that the maximum current is limited for safety reasons to up to 2,000 mA or more, preferably to a range of 600 to 1,000 mA. Electronic circuit 4 can also encompass a timer 5b to ensure that the device stops working if left unattended after a specified period of time, preferably 30 to 90 minutes. Light-emitting diode 8b signals that the device is either working or ready to work, or in standby, preferably by blinking and staying on, respectively. The power plug serves to power the device using an external power source, the plug preferably being a standard USB port 6a of FIG. 1. Plastic anchor 19 of FIG. 3 or hook 21 of FIG. 5 serve to hang the device from the power cable or hung from itself so that the device may be employed by hanging the device, for example from the side of a bucket.

In a first embodiment, the method comprises the step of reacting naturally-occurring chloride ions in water to form hypochlorite. The device is connected to a power source with its USB port 6a of FIG. 1. The part of the device containing the electrodes is vertically or obliquely, and partially introduced for example into a vessel or the neck of a bottle containing said chloride aqueous solution so that at least some fraction of at least two electrodes are immersed while maintaining the electronic-containing part above the liquid level as in FIG. 4. The device can be held manually, left to stand on the bottom of a shallow vessel, for example a jar, bucket, or a glass, or held by, e.g., an anchor 19 of FIG. 3 or hook 21 of FIG. 5, a magnet placed on the back of the apparatus, a string, a wire, or other similar fastener. Light- emitting diode 8a can signal that the device is energized and ready to function or functioning by blinking. Provided that the user does not remove the device from the reaction medium because the concentration of hypochlorite was deemed sufficient by her tracking time, the characteristic odor of chlorine, or some other resulting chemical agent or electrochemical property, after about 30 to 90 minutes the current is cut for safety reasons in case the user forgot the device working unattended. Light-emitting diode 8b shown in FIG. 2 may turn from blinking to always on to signal that the device is no longer generating hypochlorite. The solution is progressively enriched in hypochlorite and depleted in chloride as the electrochemical reaction takes place, according to

NaCl + ¾0 NaClO + H ₂

as described in the background section. Under ideal conditions, one mole of chloride ions reacts to form one mole of hypochlorite. The sodium cations of the mentioned anions (i.e. chloride and hypochlorite) are considered for the sake of exemplification. In actuality it has been shown that some other reactions may undergo in parallel. The evolved hydrogen in the form of bubbles aids in creating convective, turbulent currents that favor the mixing of said solution and replenish reagents over the surface of the electrodes while removing the products away from it. Evolved hydrogen is very insoluble in water so it is forced to bubble out. Upper slits in the body allow said hydrogen gas to safely dissipate into the air. The user can stop the generation of hypochlorite when a useful concentration has been reached. Said resulting concentration is a function of the initial chloride concentration in water and the time allowed for the device to work. Simple tables or graphs can be provided together with the device allowing the user to establish the desired variables to achieve a useful concentration. The required time is usually in the range of 1 to 15 minutes and more preferably at a range of 5 to 7 minutes. The present embodiment is useful for example when the disinfection of harvested water is desired, such as from shallow wells, rivers, aquifers or similar bodies of water, or mixtures of salty or brackish waters. A plastic bottle may be filled with said water and the device introduced through its neck while partially immersing the electrodes in the water. Since most waters contain useful quantities of chloride, the equivalent of some to several drops of commercial sodium hypochlorite solution can be generated in situ in a few minutes, thus allowing the affordable, widespread, and in situ disinfection of waters in general.

In another embodiment, the method comprises the initial step of adding a source of chloride ions to the water such as from sodium chloride in the form of granular salt, and then mixing to achieve a chloride-rich solution. The source of chloride may also be salts of potassium, calcium, lithium, or other alkaline metal of groups I and II, or combinations thereof. Salt may be added to water or water may be added to salt depending on the preferred usage by the user. For the particular case where sodium chloride is employed, the resulting salt concentration is usually in the range of 0.1 to 36 wt%, typically about 0.5 to 20 wt%. Said solution is preferably produced or placed in a shallow vessel such as a jar, bucket, glass or specially- designed flask for this purpose. The electrode-containing part in the present device are partially immersed in the solution and the system is allowed sufficient time to undergo electrolysis following the method as depicted before, preferably in the range of 30 seconds to 15 minutes. The user may decide that the solution has reached the desired concentration based on tables and instructions provided tracking time externally, or from her own perception of the passage of time, or from perceiving a strong-enough odor of chlorine, or with an integrated or external sensor which measures directly or indirectly the concentration of hypochlorite or active chlorine. One method to measure the hypochlorite concentration is through complex impedance measurements of the reacting medium either employing or not existing electrodes. A solution relatively enriched in hypochlorite is thus available for the user for its immediate or later use in a similar manner to commercial sodium hypochlorite solutions. The resulting product may thus be employed for any application where commercial hypochlorite solutions are employed, for example to achieve the disinfection of pools of water, objects, surfaces, organic tissues, utensils, the bleaching of fabrics, floors, or carpets, etc. In another embodiment, the device is employed as a general electrolysis device not limited to the production of hypochlorite. The electrode materials or sizes, or voltage supplied by voltage regulator 7a may be changed as required according to the specifications following the state of the art. Thus, when enabled by the setup and choice of conditions, hypobromite or hypobromous acid may be produced from bromide-containing solutions, hypoiodite or hypoiodous acid may be produced from iodide-containing solutions, hydrogen and oxygen may be produced from alkaline or acidic solutions, and in general any electrochemical reaction thermodynamically susceptible of undergoing may be achieved.

In another embodiment, the device includes one or more power sources, such as for example in the form of one or more batteries or rechargeable batteries, fuel cells, capacitors, thermoelectrical generators (such as a Peltier-effect materials) or radioisotope generators, or the potentiality of including said power sources, such as for example in the form of battery holders, placers or clips, or of generating said power, such as in the form of hand-operated generators (sometimes known as“dynamo”) or photovoltaic panels. Each of these power sources may be placed in a suitable place into the body of the device.

In another embodiment, the method comprises a further step of tying the power cable around or through plastic anchor 19 of FIG. 3 or hook 21 of FIG. 5, and hanging the device from a higher point before introducing the electrodes into the water.

In another embodiment, the method comprises a further step of holding or hanging the device with a rigid or flexible wire, string or other similar fastener.

In another embodiment, the device is hermetically sealed mechanically or with a sealant such as epoxy- or silicone-based sealants. The method further comprises the step of completely immersing the device in the chloride solution.

In another embodiment, a connector other than a USB port is employed in place of USB port 6a. For example, if it is desired to power the device using Apple chargers, a“Lightning” port may be employed. In the future, power supplies may employ standards other than that of USB. It is thus obvious that the preferred connector may follow the standards of that time.

In another embodiment, the device floats on the aqueous solution resembling a buoy, preferably maintaining at least some part of the electronics-containing part of the body above water level, so that the device may be introduced and employed floating in a bucket full of water, or in a pool, or similar containers containing water. To achieve said flotation, the device may be self-floating by comprising a hollow body, or contain a flotation element in its inside, or employ an attachable flotation device such as for example a toroidal element resembling a life-saver.

Example 1

In order to examine the electrochemical activity of the setup and to select an useful operating voltage, a solution of 15.3 wt% NaCl was prepared by mixing 18.0 g reagent-grade NaCl with 100.0 g distilled water and stirred at 22 °C to obtain a clear solution. Later, 7 cm of the device containing the pair of mixed-metal oxides coated electrodes placed side-by-side and separated 1.0 mm between each other was introduced into the solution. The positive terminal of a regulated power supply (Full Energy, DC Power Supply HY3005D) was connected to the anode and the negative terminal to the cathode. Several different voltages were tested and the voltage and initial current (i.e. at t = 0) were obtained. A plot with the results is shown in FIG. 4. It is clear that no electrolysis underwent below 2.0 V, while at above approximately 2.9 V some oxygen began to evolve as was observed visually and can be inferred from the change of slope in the plot.

Example 2

In order to study the hypochlorite-generation capabilities of the setup, a solution of 15.3 wt% NaCl was prepared by mixing 18.0 g reagent-grade NaCl with 100.0 g distilled water and stirred at 20 °C to obtain a clear solution. A 1.0 ml sample of the solution was measured with HI771 (Hanna Instruments) to obtain 0 ppm chlorine. The part of a device containing a pair of mixed- metal oxides coated electrodes placed side-by-side and separated 1.0 mm between each other was introduced 7 cm into the solution. The positive terminal of a regulated power supply (Full Energy, DC Power Supply HY3005D) was connected to the anode and the negative terminal to the cathode. The voltage was stabilized at 2.80 V. Vigorous bubbling was observed evolving from the electrodes. After 10 minutes a 1.0 ml sample was extracted, diluted to 10.0 ml and measured with HI771 to obtain 1,331 ppm chlorine. After 30 minutes a 1.0 ml sample was extracted, diluted to 10.0 ml and measured with HI771 to obtain 3,377 ppm chlorine.

Example 3

In order to study the hypochlorite-generation capabilities of the setup, a solution of 26.5 wt% NaCl was prepared following a procedure similar to that of example 2. The voltage was stabilized at 3.50 V. The initial chlorine concentration was 0 ppm. After 10 minutes the chlorine concentration was measured as 3,476 ppm. After 30 minutes the chlorine concentration was measured as 12,597 ppm.

Example 4

In order to study the hypochlorite-generation capabilities of the setup when only naturally- occurring chlorides are present, a sample of 300 ml of mineral water with a chloride concentration of 70 mg/l was placed in a beaker. The part of a device containing a pair of electrodes as described in previous examples was introduced 8 cm into the solution and left to produce electrolysis at a room temperature of 24 °C. Evolution of fine bubbles was observed from the cathode and the evolution and re-dissolution of larger bubbles was observed from the anode. After 5 minutes there was a slight penetrating chlorine odor above the liquid. The device was removed and the active chlorine level was measured as 6 ppm. For comparison, the United States Environmental Protection Agency recommends adding 2 drops of commercial bleach per 1 quart/liter of water (resulting in a 5.25 ppm solution when 5.25 wt% bleach is employed) and let to stand for 30 minutes in order to disinfect water for human consumption.

Example 5

In order to study the hypochlorite-generation capabilities of the setup when only naturally- occurring chlorides are present, a 1,500 ml of mineral water with a chloride concentration of 70 mg/l was placed in a plastic PET bottle. The part of a device containing a pair of electrodes as described in previous examples was introduced 8 cm into the solution through the bottle neck and left to produce electrolysis at a room temperature of 24 °C. Evolution of fine bubbles was observed from the cathode and the evolution and re-dissolution of larger bubbles was observed from the anode. After 5 minutes there was a slight penetrating chlorine odor above the liquid. After 9 minutes the device was removed, the content of the bottle mixed by swirling, and the active chlorine level was measured as 5 ppm. Since the bottle was not mixed during electrolysis, differences when compared to example 4 could be explained by the different local conditions prevalent surrounding the electrodes, e.g. pH, chloride concentration, bubbling-induced mixing, etc. in the larger flask.

Although this invention has been described in detail with particular reference to the preferred embodiments, other embodiments can achieve almost the same results. Variations and modifications of the present invention will be considered obvious to those skilled in the art and it is intended to cover in the appended claims all such modifications and equivalents. It is contemplated that any embodiment discussed in this specification can be implemented with respect to any method, kit, reagent, or composition of the invention, and vice versa. Furthermore, compositions of the invention can be used to achieve methods of the invention.

It will be understood that particular embodiments described herein are shown by way of illustration and not as limitations of the invention. The principal features of this invention can be employed in various embodiments without departing from the scope of the invention. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, numerous equivalents to the specific procedures described herein. Such equivalents are considered to be within the scope of this invention and are covered by the claims.

All publications and patent applications mentioned in the specification are indicative of the level of skill of those skilled in the art to which this invention pertains. All publications and patent applications are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.

The use of the word“a” or“an” when used in conjunction with the term“comprising” in the claims and/or the specification may mean“one,” but it is also consistent with the meaning of “one or more,”“at least one,” and“one or more than one.” The use of the term“or” in the claims is used to mean“and/or” unless explicitly indicated to refer to alternatives only or the alternatives are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and“and/or.” Throughout this application, the term“about” is used to indicate that a value includes the inherent variation of error for the device, the method being employed to determine the value, or the variation that exists among the study subjects.

As used in this specification and claim(s), the words “comprising” (and any form of comprising, such as“comprise” and“comprises”),“having” (and any form of having, such as “have” and“has”),“including” (and any form of including, such as“includes” and“include”) or“containing” (and any form of containing, such as“contains” and“contain”) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps. In embodiments of any of the compositions and methods provided herein,“comprising” may be replaced with“consisting essentially of’ or“consisting of’. As used herein, the phrase “consisting essentially of’ requires the specified integer(s) or steps as well as those that do not materially affect the character or function of the claimed invention. As used herein, the term“consisting” is used to indicate the presence of the recited integer (e.g., a feature, an element, a characteristic, a property, a method/process step or a limitation) or group of integers (e.g., feature(s), element(s), characteristic(s), property(ies), method/process steps or limitation(s)) only.

The term “or combinations thereof’ as used herein refers to all permutations and combinations of the listed items preceding the term. For example,“A, B, C, or combinations thereof’ is intended to include at least one of: A, B, C, AB, AC, BC, or ABC, and if order is important in a particular context, also BA, CA, CB, CBA, BCA, ACB, BAC, or CAB. Continuing with this example, expressly included are combinations that contain repeats of one or more item or term, such as BB, AAA, AB, BBC, AAABCCCC, CBBAAA, CABABB, and so forth. The skilled artisan will understand that typically there is no limit on the number of items or terms in any combination, unless otherwise apparent from the context.

As used herein, words of approximation such as, without limitation,“about”, "substantial" or "substantially" refers to a condition that when so modified is understood to not necessarily be absolute or perfect but would be considered close enough to those of ordinary skill in the art to warrant designating the condition as being present. The extent to which the description may vary will depend on how great a change can be instituted and still have one of ordinary skill in the art recognize the modified feature as still having the required characteristics and capabilities of the unmodified feature. In general, but subject to the preceding discussion, a numerical value herein that is modified by a word of approximation such as“about” may vary from the stated value by at least ±1, 2, 3, 4, 5, 6, 7, 10, 12 or 15%.

All of the compositions and/or methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the compositions and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the compositions and/or methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the invention. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the invention as defined by the appended claims.

To aid the Patent Office, and any readers of any patent issued on this application in interpreting the claims appended hereto, applicants wish to note that they do not intend any of the appended claims to invoke paragraph 6 of 35 U.S.C. § 112 as it exists on the date of filing hereof unless the words“means for” or“step for” are explicitly used in the particular claim.

For each of the claims, each dependent claim can depend both from the independent claim and from each of the prior dependent claims for each and every claim so long as the prior claim provides a proper antecedent basis for a claim term or element.