Description:TITLE OF THE INVENTION:
Method for the production of plasma activated water

FIELD OF THE INVENTION:
The present invention relates to the field of fertilizers and pesticides used while growing various plants and crops and particularly relates to a simple and efficient method for producing plasma activated water at minimal cost.

BACKGROUND OF THE INVENTION:
Plasma is referred to as the fourth state of matter, the others being solid, liquid and gas. It comprises of positive and negative ions, electrons, excited and neutral atoms, free radicals, molecules in the ground and excited state and uv photons. When electrical energy is applied at a high voltage and high frequency across two electrodes, the dielectric medium between the electrodes breaks down. If this dielectric medium is air or gas, they get ionized and produce a lot of heat. This ionized gas is known as plasma. If this ionization is above a certain level, the medium becomes very hot and is known as hot plasma. The temperature of this hot plasma is in thousands of degree Celcius. However if the temperature of the plasma is in the range of around 50 degrees, the plasma is defined as cold plasma. Dielectric barrier discharges (DBD), plasma jets and corona discharges are widely used plasma sources for food applications. Many scientists and researchers have employed cold plasma in several food applications like microbial disinfection, enzymatic inactivation, improving the cooking quality of rice varieties, starch modification, enhancing seed generation etc.
Plasma activated water (PAW) is produced primarily from cold plasma by making use of water, air and electricity. Ambient air is brought into the plasma phase with electrical energy, the activated air is then brought into contact with water. The reactive oxygen and nitrogen dissolve into water creating plasma activated water. In general plasma activated water is generated by treating water with cold atmospheric plasma (CAP) using controllable parameters like plasma forming voltage, carrier gas, temperature, pulses or frequency, as required.
A number of patents and patent applications are available in the prior art for the production of plasma activated water.
US 2022332606 describes a plasma activated water production system includes a plasma reactor and a membrane concentrator. The plasma reactor includes an internal cavity, at least one electrically-conductive inlet capillary and outlet capillary. A mixing chamber has a feed gas inlet, a liquid inlet, and a mixed gas and liquid outlet. A power source is provided. The plasma reactor propagates a plasma discharge between the inlet capillary and the outlet capillary. A membrane concentrator includes a water flow channel with a water inlet and a water outlet, a dry gas inlet and a humidified gas outlet. An ion selective membrane is provided, and water will pass through the membrane into the dry gas, and the water leaving the membrane concentrator will have increased concentrations of nitrates, nitrites and hydrogen peroxide. An electrodialysis embodiment and a method of generating plasma activated with increased concentration of nitrates, nitrites and hydrogen peroxide are also disclosed.
WO 2023015343 provides a plasma-bubble reactor, reactor system and method for producing hydrogen peroxide (H2O2), one or more hydrocarbon(s), and syngas. The reactor comprises a vessel configured to hold a liquid; and a plasma generating means, in association with the vessel, configured to receive an input feed comprising carbon dioxide (CO2) gas and generate a plasma from the CO2 gas to produce an activated CO2 gas encapsulated within a plurality of bubbles formed in the liquid, wherein the activated CO2 gas reacts with water (H2O) at a plasma-liquid interface formed between the bubbles and the surrounding liquid to produce hydrogen peroxide (H2O2), one or more hydrocarbon(s) and syngas.
AU 2021101811 discusses a device for preparation of high-throughput plasma-activated liquid. The device includes a pretreatment tank, at least two plasma jet devices, at least two high-voltage electric field generators, and at least two transformers. The pretreatment tank includes an input end and an output end. The input end is provided with a first water inlet valve. The output end is connected to a first plasma jet device. The at least two plasma jet devices are connected together, end to end, and a last plasma jet device is connected to a water outlet valve. Each of the at least two plasma jet devices is connected to a high-voltage electric field generator and a transformer. Each of the at least two plasma jet devices includes at least two plasma jet generators, a water tank, and at least two controllers. Plasma jet generator Valve Water inlet Pretreat ing tank Backflow Water outlet Valve.
KR 102475982 discloses a plasma active water production device in which plasma is stably generated and maintained in the process of converting water into active water by plasma treatment. The present invention provides plasma between a discharge electrode located inside a dielectric tube, a conduction electrode installed at an end of the dielectric tube to deliver plasma of the discharge electrode, and a conduction electrode installed at a predetermined interval from the conduction electrode and a counter electrode for generating plasma, and an injector for injecting water to pass through the plasma generated between the conduction electrode and the counter electrode.
KR 20220031243 gives a plasma processing system, comprising: a plasma generating unit having a plasma source for generating reactive species for plasma processing; A plasma processing unit for plasma processing an object to be treated by introducing active species therein; and a fluid transfer unit for transporting the active species generated in the plasma generator to the plasma processing unit, wherein the plasma source is spaced apart from the plasma processing unit.
CN 115367840 discloses a plasma activated water preparation device and method, relates to the field of plasma activated water preparation, and solves the technical problems of low plasma energy utilization rate and low activated water preparation efficiency of a plasma activated water preparation device in the prior art. The plasma activated water preparation device comprises a container, a microbubble generation structure, a discharge assembly, a gas inlet assembly and a liquid inlet assembly, and the discharge assembly is used for discharging and ionizing gas in micropores of the microbubble generation structure to generate plasma; and the ionized plasma forms microbubbles on the surface of the microbubble generation structure and enters the liquid to be treated. According to the device, microbubble discharge between gas and liquid phases is realized, so that the energy utilization rate and the gas-liquid mass transfer efficiency of plasmas can be improved, and the preparation efficiency of plasma activated water is greatly improved; and the concentration of active particles such as H < + >, NO2 <->, NO3 <-> and H2O2 in the prepared activated water can be greatly improved under the same condition.
CN 115477367 provides a a water activating device and activated water preparation equipment, and relates to the technical field of activated water preparation equipment. The water activating device comprises an insulating mounting seat and a reaction cover, wherein a ground electrode wiring part is arranged on the insulating mounting seat; the reaction cover is mounted on the insulating mounting seat, a gas channel is formed in the reaction cover, a high-voltage electrode is mounted in the gas channel, a through hole for communicating the gas channel with a water body is formed in the reaction cover, a gas-liquid interface can be formed at the through hole, and the high-voltage electrode can discharge electricity with the reaction cover and the gas-liquid interface respectively. Plasma generated by discharging can enter the water body through the through holes. Based on the technical scheme, the fluctuation of a gas-liquid interface is relatively stable, so that arc discharge is relatively stable, glow discharge is generated between the high-voltage electrode and the reaction cover, plasma is generated under the combined action of the arc discharge and the glow discharge, and the treatment efficiency of activated water is further improved.
CN 115643665 describes a plasma in-situ activation water mist treatment system and method, plasma jet is formed in a first medium pipe, when the high-speed plasma jet flows through a throat part, liquid to be treated in a first container is sucked into the throat part due to the local pressure difference, and the liquid to be treated in the first container is subjected to in-situ activation; liquid to be treated forms small liquid drops under the impact of high-speed plasma jet, and a large number of short-life free radicals, ions and solvated electrons in the plasma jet quickly act on the liquid drops near the surfaces of the liquid drops, so that plasma in-situ activation of water mist is realized; by controlling the conversion valve and manually switching the flow direction of the plasma jet flow, the plasma jet flow can be directly sprayed out from the free end of the second pipe part in the form of activated water mist and can be used immediately after being manufactured, the plasma jet flow can also enter the second container through the second guide pipe, liquid to be treated in the second container is further treated, and the liquid to be treated flows into the first container again. The water mist is repeatedly absorbed by the throat part and activated in situ, so that circular treatment of the plasma activated water mist is realized.
CN 217808834 discloses a plasma activated water preparation device which specifically comprises a gas-phase discharge assembly 100, a gas-liquid mixed-phase discharge assembly and a container, a to-be-treated solution is contained in the container, the gas-phase discharge assembly 100 ionizes air and generates air plasmas, and the air plasmas are transmitted to the to-be-treated solution and gradually dissolved into the to-be-treated solution. H < + >, NO2 <-> and NO3 <-> are generated in the solution to be treated; the gas-liquid mixed-phase discharge assembly is ionized on a gas-liquid interface, and at the moment, a large amount of H2O2 is generated in liquid of the gas-liquid interface. In the whole process, a large amount of gas plasmas (including H < + >, NO2 <->, NO3 <-> and the like) and a large amount of H2O2 are generated at the same time through a scheme of combining gas-phase discharge and gas-liquid mixed-phase discharge, and the preparation efficiency of the plasma activated water can be remarkably improved.

Although a number of methods for manufacturing plasma activated water are available in the prior art, generally Gliding Arc or Dielectric Barrier Discharge are commonly used for the generation of Plasma Activated Water. Sometimes a combination of both hot and cold plasma have been used for the generation of Plasma Activated Water. All these processes require sophisticated controllable devices for generating high voltages 25 KV to 50 KV at high frequencies 50 khz to 75 khz, carrier gas, pumps, air compressors etc., which makes the manufacturing process costly. Hence a simple, efficient, compact and cost-effective method which requires lesser, simple and easily available materials for the production of plasma activated water, is the need of the day.

OBJECT OF THE INVENTION:
The main object of the invention is to provide a method for the production of plasma activated water which is a simple, compact and efficient method to produce plasma activated water at minimal cost.
Another object of the invention is to provide a method for the production of plasma activated water which does not require sophisticated power source and control systems, pumps and air compressor for the production.
Still another object of the invention is to provide a method for the production of plasma activated water in which higher concentration of reactive oxygen and nitrogen species are dissolved in water to produce plasma activated water.
Yet another object of the invention is to provide a method for the production of plasma activated water which is simple, reliable, user-friendly and cost effective.

SUMMARY OF THE INVENTION:
The present invention relates to a method for the production of plasma activated water which can be used as a fertilizer and insecticide. This method involves controlled flow of water through channels of minimal thickness. These channels are made in insulating material with high dielectric strength. Electrodes with fine wires connected to them are placed such that the wires are 2 mm above each channel. Power cards are connected to each electrode. On pressing the switch on, the power cards get activated and dielectric barrier discharge happens. As the channels are only 2 to 5 mm thick, water in the channels is exposed to this discharge uniformly. As the fine wires connected to the electrodes are spread throughout the length of the channels, the entire water channel is continuously exposed to the discharge uniformly. After the water gets fully activated, it gets collected in the collector, for further use.

BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 gives the labeled diagram of the method for producing plasma activated water.
Fig. 2 gives the diagram of the power card.

DETAILED DESCRIPTION:
The nature of the invention and the manner in which it is performed is clearly described in the specification. The invention has various components and they are clearly described in the detailed description.
Plasma Activated Water (PAW) is becoming quite popular nowadays due to its wide applications and is catching up fast with the scientific community as well as commercial applications. Laboratory and field trials are being conducted all over the world to study the benefits of Plasma Activated Water in agriculture. The results are quite promising and PAW is expected to help agriculture in a big way. Excessive use of fertilizers and pesticides/insecticides have greatly polluted the soil. PAW can replace fertilizers and pesticides to a considerable extent and can protect the soil from such abuses.
The present invention provides a method for the production of plasma activated water which is a simple and efficient method. It involves the use of very few and simple components due to which the unit prepared for the production of PAW is compact and cost effective. This unit can be scaled up by adding modules for higher production. The use of sophisticated power sources and controls have been replaced by simpler ones and the requirements for pumps and gas carriers have been eliminated.
The present invention involves a power card which generates the required power at desired voltage & frequency and works on a single phase supply of 230 volts and 50 hz. A plurality of such cards can be used in parallel to supply the required power for the generation of the desired quality and quantity of Plasma Activated Water. Moreover the present invention involves the water to be flown through thin channels with dielectric base. The number of thin water channels is equal to the number of outlet pipes provided for flowing out water from the input water tank. Water glides over these channels forming a film of 2 to 5 mm thickness. Flow of this water is controlled by rotameters. Fine wires containing electrodes connected with the power cards are arranged in an array over these channels, which ensure uniform dielectric barrier discharge with water through the atmospheric air. The controlled flow of water ensures uniform exposure and ionization. As the major constituents of air are nitrogen and oxygen, higher concentrations of reactive oxygen and nitrogen get dissolved in the water to produce Plasma Activated Water.
Fig. 1 gives the labeled diagram of the method for producing plasma activated water. As shown in Fig. 1, the various components used in the present invention and their working is as follows:
Water Tank (1): A water tank is provided at the starting point, which may be connected to water tap, in which raw water is stored to flow out in a controlled manner during the production of plasma activated water.
Flow Control Valve (2): Two (or more) flow control valves are provided on the two (or more) outlet pipes for flowing out of water from the water tank. These flow control valves control the flow of water such that the desired thickness of water layer (2-5 mm) flowing through the channels is maintained.
Copper Electrode (3): These copper electrodes have fine wires connected to them such that they are placed 2 mm above the level of water flowing through the channels. 16 (or more) such copper electrodes are present above the water channels.
Water Channel (4): The water flowing out in a controlled manner glides through 2 (or more) such channels at a desired thickness and flow rate. The channels are made of insulating material with high dielectric strength. The length of these water channels is 500 mm.
Array of Power Cards (5): Power cards supply the desired power at desired voltage and frequency for generating plasma by ionizing the atmospheric air due to which dielectric barrier discharge takes place through water. An input supply of 230 volts or 415 volts is given to the power cards. The card rectifies the input voltage with the help of the connected 12 diodes (D1 – D12). The resulting DC voltage is chopped with the help of Silicon Controlled Rectifier X1 at 150 hz. This leads to the boosting of the input voltage which is further multiplied due to the capacitors C1 – C7 and inductors L1 – L4. In this circuit, different resistors are used for damping and limiting purposes. The output voltage received at the connector N2 is further amplified with the help of ferrite core transformer, which has 3 turns of wire in the primary and 85 turns of wire in the secondary winding of the transformer. The output received at 85 turns winding is 25 KV to 50 KV @50khz depending upon the input supply of 230 volts or 415 volts. The rate of ionization reduces at lower voltage. Output A & B is used for driving the Silicon Controlled Rectifier using the IC 555 as per the circuit shown in Fig. 2.
Multiple PCB cards depending upon the production capacity of the unit for producing Plasma Activated Water, are added to enhance the capacity. Each card is connected to a separate set of electrodes. The other output of the card is connected to the bottom of the water channel which is non-conducting. A switch is provided to switch on and off the power cards.
Sump/Collector (6): This is the container which collects the Plasma Activated Water. The water from the sump/collector, can be taken away for use or the collector can directly be connected to a spraying machine for spraying the Plasma Activated Water on plants.
The method for the production of plasma activated water involves the following steps:
(i) Connecting all the required components for producing plasma activated water as displayed in Fig.1.
(ii) Switching on the power cards (5).
(iii) Opening the flow control valves (2) such that controlled amount of water flows out of the tank and enters the water channels (4) such that the thickness of the water flowing through the channels is 2 – 5 mm.
(iv) Due to the switching on of the power cards (5), electric current flows through the electrodes (3) and flows to the fine wires placed 2 mm above the water level flowing through the water channels (4). This electric current causes ionization of the air present between the fine wires and the water channels due to which dielectric barrier discharge happens.
(v) The water flowing through the channels is exposed to this discharge uniformly as the layer of the water is only 2-5 mm thick.
(vi) The entire water flowing through the channel is continuously exposed to the discharge till it crosses the complete length of the channel which is 500 mm.
(vii) Thus the complete volume of water entering the water channels, gets fully activated and Plasma Activated Water is collected in the sump/collector for further use or spraying on plants.

The method for the production of plasma activated water is highly advantageous as it is simple in operation, maintenance free and low cost method for producing plasma activated water which acts as a fertilizer and pesticide during the growth of many plants. Nitrogen is the major component in fertilizers used for the growth of plants and oxygen is also required for the growth of plants. The plasma activated water produced using the method of the proposed invention has nitrates, nitrites and oxygen species due to which it acts as a fertilizer for the growth of plants. Moreover H2O2 in the plasma activated water has been proven to have good insecticidal and pesticidal properties. Hence the plasma activated water eliminates the requirement of spraying pesticides on the crops. In contrast to most plasma activated water producing methods, which involve a combination of hot plasma and cold plasma which has to be cooled down before use, the present invention uses cold plasma due to which the plasma activated water produced can be directly applied on the fields and crops. As low energy PCB cards are used for ionization, limited and continuous ionization of air occurs due to which controllable heat is generated. Moreover in contrast to the other equipments available for producing plasma activated water, which are complicated, require a range of sophisticated components and expensive to be used by farmers, the plasma activated water generating unit using the method of the present invention is user friendly, simple in operation, involves the use of minimal and easily available components, is maintenance free and of low cost due to which it is affordable to the farmers for use in their fields. This plasma activated water when sprayed on crops and in soil, does not harm the crops and soil as is common with conventional chemical fertilizers and pesticides. Hence the present invention is highly advantageous.

Although the preferred embodiment as well as the construction and use have been specifically described, it should be understood that variations in the preferred embodiment could be achieved by a person skilled in the art without departing from the spirit of the invention. The invention has been described with reference to specific embodiments which are merely illustrative and not intended to limit the scope of the invention as defined in the claims.
, Claims:We claim,
1. A method for the production of plasma activated water which is a simple, user friendly and cost effective method for the production of plasma activated water to be used as a fertilizer and pesticide wherein the components required for producing the plasma activated water are:
• water tank (1) – for storing raw water which is flowed out in a controlled manner for producing the plasma activated water;
• flow control valves (2) – provided on outlet pipes for the raw water to flow out of the tank;
• copper electrodes (3) – having fine wires connected to them such that they are placed 2 mm above the level of water flowing through the water channels;
• water channels (4) – made of insulating material with high dielectric strength for gliding of the water flowing out in a controlled manner from the water tank (1);
• array of power cards (5) – which are PCB cards working on a single phase supply of 230 volts and 50 hz and wherein one end of the card is connected to a copper electrode (3) and the other to the bottom of the water channel (4) which is non-conducting wherein a switch is provided to switch on and off the power cards (5);
• sump/collector (6) – which collects the plasma activated water produced;
wherein the method for the production of plasma activated water involves the following steps:
(i) connecting the components for producing plasma activated water as displayed in Fig. 1;
(ii) switching on the power cards (5);
(iii) opening the flow control valves (2) such that a controlled amount of water flows out of the tank and enters the water channels (4) such that the thickness of the water flowing through the channels is 2 – 5 mm;
(iv) flowing of the electric current from the power cards (5) through the electrodes (3) to the fine wires placed 2 mm above the water level flowing through the water channels (4);
(v) ionization of the air present between the fine wires and water flowing through the water channels (4) causing dielectric barrier discharge;
(vi) uniform exposure of the flowing water to the dielectric barrier discharge till it crosses the complete length of the water channel (4); and
(vii) collection of the plasma activated water in the sump/collector (6).
2. The method for the production of plasma activated water as claimed in claim 1 wherein the power cards (5) rectify the input voltage with the help of the connected 12 diodes (D1 – D12) and the resulting DC voltage is chopped with the help of Silicon Controlled Rectifier X1 at 150 hz which boosts the input voltage which is further multiplied due to the capacitors C1 - C7 and inductors L1 – L4;
wherein the output voltage received at connector N2 is further amplified with the ferrite core transformer having 3 turns of wire in the primary and 85 turns of wire in the secondary winding of the transformer;
wherein the output received at 85 turns winding is 25 KV to 50 KV @ 50 khz depending on the input supply of 230 volts or 415 volts;
wherein the rate of ionization reduces at lower voltage; and
wherein the output A & B is used for driving the Silicon Controlled Rectifier using IC 555.
3. The method for the production of plasma activated water as claimed in claim 1 wherein the number of outlet pipes, flow control valves (2) and water channels (4) are the same.
4. The method for the production of plasma activated water as claimed in claim 1 wherein a plurality of power cards (5) are attached in parallel to supply the required power for producing the desired quality and quantity of plasma activated water.
5. The method for the production of plasma activated water as claimed in claim 3 wherein each power card (5) is attached to a single copper electrode (3).
6. The method for the production of plasma activated water as claimed in claim 1 wherein the length of the water channels (4) is optimally 500 mm.
7. The method for the production of plasma activated water as claimed in claim 1 wherein the sump/collector (6) can be directly connected to a spraying machine for spraying the plasma activated water on the crops or on the soil.