WO1997044280A1

WO1997044280A1 - Floating electrode for electrolysis, electrolytic apparatus and plant growing method

Info

Publication number: WO1997044280A1
Application number: PCT/JP1996/003133
Authority: WO
Inventors: Tetsuro Tojo; Minehiro Kamiyama; Osamu Yoshimoto
Original assignee: Toyo Tanso Co., Ltd.
Priority date: 1996-05-21
Filing date: 1996-10-24
Publication date: 1997-11-27
Also published as: JPH09310190A; AU7337196A

Abstract

A float (2) equipped with a pair of positive and negative electrodes (4, 4) is floated on an electrolyte (8) so that the electrodes (4, 4) may move up and down in accordance with the change of the level of the electrolyte (8). This prevents variations of electrolytic conditions such as changes in effective electrode area in contact with the electrolyte (8), and ensures stable electrolysis. Electrolysis of water is carried out by using an electrolytic apparatus that comprises an electrolytic bath (7), a water supply pipe and a drain pipe fitted to the electrolytic bath (7) and a pair of electrodes (4, 4) including a carbonaceous positive electrode, and the electrolyzed water containing carbon dioxide is sprayed for growing terrestrial plants. When the quantity of electrolyzed water decreases due to consumption, water is filled through the water supply pipe and electrolysis is repeatedly conducted. The supply of carbon dioxide solution accelerates photosynthesis in terrestrial plants such as agricultural and horticultural plants and their growth is insured.

Description

Description Floating electrode for electrolysis, electrolyzer and plant growing method

The present invention relates to a floating electrode for electrolysis, an electrolyzer, and a method for growing plants. In particular, a positive electrode and a negative electrode are immersed in water or an aqueous solution (hereinafter simply referred to as water) to perform electrolysis. The present invention relates to a plant growing method in which electrolyzed water used in the electrolysis apparatus used and carbon dioxide dissolved by the electrolysis are mainly used for growing terrestrial plants. Background art

Conventionally, an electrolysis method of immersing a positive / negative pair of electrodes in an electrolytic solution to perform electrolysis is a well-known technique.In general, a positive / negative pair of electrodes is immersed in an electrolytic solution contained in an electrolytic cell and a diaphragm is provided between both electrodes. Electrolysis is performed. In this case, the electrodes are mounted on the electrode holder in parallel with the positive / negative pair, and the electrode holder is fixed to the electrolytic cell to be immersed in the electrolytic cell.

By the way, the conventional electrolysis method uses an electrolytic cell and an electrode fixedly provided in the cell, and usually has a fixed volume of electrolysis so as not to change the effective electrode area immersed in the electrolytic solution. Electrolysis is performed while injecting and discharging the electrolyte so that the electrolysis power is maintained at a constant level or the level of the electrolyte in the tank at all times, and stable electrolysis has been performed. .

Depending on the application, it may be desirable to make the volume of electrolyzed water variable. For example, in the method for producing a carbon dioxide solution for plant growth proposed by the present applicant (refer to Japanese Patent Application No. 6-257697 and H Patent Application No. 341042), at least the anode is used. Electrolysis of water using a carbonaceous electrode for the anode Carbon dioxide is produced by the reaction to produce a solution in which carbon dioxide is dissolved, and the carbon dioxide solution is sprayed on crops and horticultural plants, and used for growing aquatic plants and the like. However, in such a case, various amounts or concentrations of carbon dioxide solution are required depending on the cultivation area of the target plant. In addition, it is necessary to produce the carbon dioxide solution each time it is used, and in order to produce a large amount, it is necessary to sequentially extract the required amount of the carbon dioxide solution. In some cases, it is necessary to produce about half the volume (liquid volume) of the electrolytic cell. In such a case, in the production using a conventional electrolysis method in which the above-described electrodes are fixed to an electrolytic cell, the amount of the electrolytic solution in the electrolytic cell fluctuates and the liquid level fluctuates. Stable electrolysis cannot be performed due to changes in electrolysis conditions such as changes in the effective electrode area. It has also been observed that during the electrolysis, the electrochemical reaction proceeds only near the interface of the water serving as the electrolytic solution, and that only the relevant portion is consumed and the electrode collapses or breaks.

Accordingly, an object of the present invention is to provide a floating electrode for electrolysis and an electrolysis method capable of stably performing an electrochemical reaction on an electrode surface even when the liquid level is changed due to a change in the amount of liquid to be electrolyzed. Another object of the present invention is to provide an apparatus for electrolysis, in which, in addition to the above-mentioned objects, a carbon electrode is consumed almost uniformly without collapsing or breaking in water electrolysis and can provide a stable electrolytic action. The purpose is to provide a floating electrode. Disclosure of the invention

The floating electrode for electrolysis of the present invention is a floating electrode in which a pair of positive and negative electrodes used for electrolysis are provided on a float. This makes it possible to float the float on the electrolyte and raise and lower the electrodes following the fluctuations in the electrolyte level, so that the effective electrode area of the electrodes immersed in the electrolyte changes. Stable electrolysis can be performed by preventing changes in conditions. In addition, since electrolysis can be performed in such a form, not only when the electrolytic solution is contained in the electrolytic cell, The above-described stable electrolysis can be performed even when the liquid level fluctuates, for example, when the electrolytic solution is injected into the electrolytic cell. Therefore, it is an effective means especially in the method for producing a carbon dioxide solution for plant growth proposed by the present applicant. That is, even if the water level in the electrolytic cell fluctuates, or where the water level changes, such as rivers and ponds, the effective electrode area of the electrode can be maintained and stable water electrolysis can be performed, and at least a carbon electrode must be used for the anode. Thus, water in which carbon dioxide that aids plant growth is dissolved can be obtained stably and efficiently.

Further, the floating electrode for electrolysis of the present invention includes, as a float, a top plate, a bottom plate, a support connecting the top plate and the bottom plate at four corners, and a flange attached to the side of the top plate.

It is possible to use one that is composed of a 10 funnel body and that has a through hole for inserting a pair of positive and negative electrodes in the top plate.

In addition, as the float, a material that is a lightweight insulator and is not affected by the electrolyte and does not deteriorate the electrolyte is preferable. For example, plastic, fiber-reinforced plastic, and the like can be suitably used. The float volume can be calculated by taking into account the electrode weight, the electrolysis density of the electrolyte, the density of the float material, the electrode immersion depth, and the like. In addition, the float shape is not particularly limited, and can be appropriately determined in consideration of the place and conditions of use.

On the other hand, during the course of research and development of the method for producing a carbon dioxide solution for plant growth of the prior application described above, the present inventors have found that the electrode (carbonaceous electrode) may be broken or broken.

20 We have been conducting research in parallel to improve the short life. As a result, phenomena such as collapse or breakage of the electrode are caused by the resistance of the electrode itself, which causes a voltage drop between the current introduction part and the tip of the electrode, and an electrolytic potential difference between the electrolyte interface and the electrode tip. It has been found that different things happen. As a result of further research, the distance between the positive electrode and the negative electrode at the electrolyte interface was determined by measuring the distance between the electrodes at the tip of the electrolyte.

It has been found that the above phenomenon can be prevented by making the distance larger than 25. That is, in the floating electrode for electrolysis of the present invention, it is preferable that the distance between the facing surfaces of the electrodes is gradually reduced as the opposite electrode is approached. As a result, in addition to efficiently obtaining water that dissolves carbon dioxide, which helps plants grow, the electrodes (carbon electrode) are prevented from collapsing or being broken, and electrodes are almost uniformly consumed. And the service life can be improved, and the electrolysis efficiency can be improved. In order to obtain such an effect more effectively, as a carbonaceous electrode, 50 to 90% of a carbonaceous substance proposed by the present applicant in Japanese Patent Application No. Hei. A substance having a substantial composition of 50% can be used, and among them, it is particularly preferable to use a composition having a composition of 50 to 80% of a carbonaceous substance and 20 to 50% of a thermosetting resin. By using a thermosetting resin, the inherent resistance that occurs when a thermoplastic resin is used is increased, and there is no generation of a lightning action that occurs when the electrolytic voltage is increased.

Next, the electrolytic device of the present invention comprises: an electrolytic cell; a water supply pipe attached to the electrolytic cell for supplying water; and a drainage pipe for extracting electrolytic water, at least provided in the electrolytic cell. A pair of electrodes, the anode of which is a carbonaceous electrode for electrolyzing water, is provided. As a result, a predetermined amount of water is supplied to the electrolytic tank from the water supply pipe, predetermined electrolysis is performed in that state, and the obtained electrolyzed water is extracted from the drain pipe, or a water pump is attached to the drain pipe to attach terrestrial plants. It is used by spraying for the growth of species. And since the use of this water reduces the amount of digestion water, supply water again from the water supply pipe to perform electrolysis. By repeating this, electrolyzed water in which carbon dioxide for plant growth is dissolved can be repeatedly and efficiently obtained.

Further, in the electrolysis apparatus of the present invention, the above-mentioned floating electrode for electrolysis of the present invention can be used by being suspended in electrolyzed water in an electrolytic cell. In this way, in addition to the above-mentioned repetition, electrolysis can be performed even during raising and lowering of the electrode, so that electrolyzed water in which carbon dioxide for plant growth is dissolved can be obtained more efficiently. A current stabilizer and a polarity switch can be interposed between the pair of electrodes and the power supply. By installing a polarity switching device, it is possible to suppress the poorly soluble salt that precipitates on the cathode, so that it is possible to more efficiently obtain electrolyzed water in which carbon dioxide of ff ffl has been dissolved in _plants.In this case, the polarity switching device The polarity switching cycle of the electrode .

It is recommended that the cycle be performed in a period of 1 to 12 hours inclusively. If the switching cycle is shorter than 1 hour, the graphite particles will be detached from the carbonaceous electrode, causing problems such as electrolyzed water becoming cloudy. In addition, when the switching period is longer than 12 o'clock, it is difficult to remove electrolytic products such as silica and silica generated at the cathode.

In addition, in the electrolysis apparatus of the present invention, in addition to using the floating electrode for electrolysis floating in the electrolyzed water in the electrolyzer, a water level sensor is controlled in the electrolyzer for each of a water supply pipe and a drain pipe. On-off valves may be provided, and these may be connected to the electrolysis control device. Further, a configuration in which an electrolysis operation condition sensor is connected to the electrolysis control device may be employed. These can be expected to automate the production of electrolyzed water in which carbon dioxide for plant growth is dissolved. As the electrolysis operation condition sensor, for example, a sensor for measuring the concentration of dissolved carbon dioxide in the electrolyzed water, a sensor for measuring weather conditions such as temperature, humidity, and atmospheric pressure can be used. These can be appropriately combined, and plants can be used. By setting the type of electrolyzed water, it is possible to produce electrolytic water adjusted to a carbon dioxide concentration suitable for the plant and to give it to the plant. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view of a floating electrode for electrolysis according to the present invention,

FIG. 2 is a sectional view taken along the line X--X in FIG. 1,

FIG. 3 is a conceptual diagram showing a use state of the floating electrode for electrolysis according to the present invention, FIG. 4 is a perspective view of another embodiment of the floating electrode for electrolysis according to the present invention, FIG. YY sectional view of FIG. 4,

FIG. 6 is a schematic diagram of an electrolytic device according to the present invention. Hereinafter, the floating electrode for electrolysis according to the present invention will be described in detail with reference to the drawings showing examples.

Referring to FIGS. 1 to 3, the floating electrode for electrolysis according to the present invention is composed of an electrode i and a float 2. Electrode 1 is plate-shaped and terminal is installed A current introducing section 3 and an electrode section 4 for performing electrolysis are formed. At the boundary between both sections, the width of the current introducing section 3 is formed larger than the width of the electrode section 4, and a step section 5 is formed. On the other hand, the float 2 is made of a lightweight thick rectangular plastic plate, and has a through hole 6 slightly larger than the cross section of the electrode portion 4 at a position symmetrical from the center. The electrode portion 4 is inserted through the through hole 6. To form a floating electrode F1 for electrolysis.

The floating electrode F1 for electrolysis is used by being floated on an electrolytic solution 8 contained in an electrolytic cell 7. Therefore, even if the electrolyte 8 decreases and the liquid level drops, or if the electrolyte 1 rises by replenishing the electrolyte 8, the electrode 1 moves up and down together with the float 2, so that the electrode 1 protruding below the float 2 is immersed. The stable effective electrolysis can be performed without changing the effective electrode area. FIG. 3 is an explanatory diagram showing an example of a use ffl form of the floating electrode F1 for electrolysis.

In the above-described embodiment, the case where the pair of positive and negative electrodes 1 is provided on the float 2 is exemplified, but not only the number but also the size of the electrodes 1 and the float 2 depends on the size of the electrolytic cell 7 to be applied. It is set to an appropriate number and size according to. The shape of the electrode 1 is not limited to a plate shape, but may be a round bar, a square bar, or the like. Also, while the float 2 has been described using a rectangular thick plate as an example, the float 2 may be formed as a disk-shaped thick plate with its side surface widened upward, or the lower part may be formed as a ship bottom type or a hemispherical shape. Is also good. With such a shape, the electrolysis floating electrode P1 is effective for electrolysis while flowing the electrolytic solution 8 into and out of the electrolytic cell 7, or for electrolysis in a place where there is a flow such as a river because the resistance to the liquid flow is small. Can be used for Also, there is no force step 5 described in the example of the mounting structure in which the electrode 1 is attached to the float 2 by simply holding the electrode part 4 of the electrode 1 through the through hole 6 of the float 2 by the step part 5. In the case of the smooth electrode 1, although not shown, the gap between the through hole (;) of the float 2 and the electrode portion 4 of the electrode 1 is filled with an adhesive, or the gap is made large, and a plate is formed there. It can be mounted by inserting a panel or wedge, or by using a well-known mounting means, such as mounting it on a bracket provided on the float 2 using a bolt or a nut. Also, an example in which the positive / negative electrode pair 1 is provided in parallel with the through hole G is shown. It may be provided so as to narrow as it goes. In this case, electrolysis can be performed on the entire surface of the opposing electrode portion 4, and the collapse of the electrode portion 4 (particularly in the case of a carbonaceous electrode) can be prevented, and the electrode portion 4 can be consumed almost uniformly. As a result, the electrode life can be improved and the electrolysis efficiency can be improved.

Also, as shown by a two-dot chain line in FIGS. 1 to 3, if necessary, the guide -11 may be attached so as to protrude laterally from the upper surface of the mouthpiece 2. . The guide bar U moves along the inner surface of the electrolytic cell 7 or along a guide rail installed in the electrolytic cell 7 (not shown) to raise and lower the floating electrode for electrolysis at a desired position in the electrolytic cell 7. Can be.

Next, referring to FIGS. 4 and 5, the floating type electrode for electrolysis according to the present invention is composed of an electrode 12 and a float 13. The electrode 12 is a plate-like carbonaceous electrode having a width of 280 mm x a length of 560 mm x a thickness of 10 and is composed of a current introduction part 14 for mounting a terminal and an electrode part 15 for electrolysis. In this embodiment, four electrodes ( 2 pairs) are used. On the other hand, the float 13 is composed of a top plate 16, a bottom plate 17, a column 18 connecting the top plate 16 and the bottom plate 17 at four corners, and a hollow float body 19 attached to the side of the top plate. And these are made of plastic. The top plate 16 is provided with four slit-shaped through holes 20 for passing the electrode 12, and the bottom plate 17 is provided with four receiving grooves 21 for receiving the lower end of the electrode 12, respectively. The electrode portion 15 of the electrode 12 is passed through the through hole 20 of the top plate 16 and the tip is placed in the receiving groove 21 of the bottom plate 17 to form a floating electrode F2 for electrolysis.

The floating electrode F2 for electrolysis is used, like the floating electrode F1 for electrolysis described above, by floating it on an electrolytic solution 8 contained in an electrolytic cell 7 or floating on a flow of a river or the like. Therefore, the electrode 12 moves up and down together with the float 13 even if the electrolyte 8 decreases and the liquid level drops, or if the level rises by replenishing the electrolyte 8 or the water level of a river or the like changes. The effective electrode area of electrode 12 is stable without change Electrolysis can be performed. Further, in the present embodiment, the gap between the through holes 20, 20 in which the positive and negative electrode pairs 12, 12 are provided is formed to be wider than the gap between the grooves 21, 21. The surface interval can be gradually narrowed, and the electrolysis can be performed on the entire surface of the opposing electrode portion 15, so that the electrode portion 15 can be prevented from being broken (particularly in the case of a carbonaceous electrode) or broken. The electrode portion 15 can be consumed almost uniformly, the life of the electrode can be improved, and the electrolysis efficiency can be improved.

Next, referring to FIG. 6, the electrolysis apparatus according to the present invention electrolyzes water using the floating 3′i electrode F2 for electrolysis shown in FIG. 4 and FIG. This is an apparatus 31 for producing a carbon dioxide solution. In this embodiment, the apparatus 31 has two electrolytic cells 32 and 33, and each of the electrolytic cells 32 and 33 is provided with a water supply pipe 34 for supplying water. The lube 35 and the water supply electromagnetic valve 36 are connected in parallel with each other, and a drain pipe 38 for extracting the electrolytic water 37 is provided with a filter check valve 39, a filter 40, and a sampling control electromagnetic valve 41. They are connected in series. Further, inside each of the electrolysis tanks 32 and 33, there are provided an upper water level sensor 42 and a lower water level sensor 43 for steady control of the electrolyzed water during electrolysis. In FIG. 6, reference numeral 44 denotes a water supply excess water level sensor, which closes the water supply electromagnetic valve 36 when water from the water supply pipe 34 is excessively supplied beyond the water supply level sensor 42. Reference numeral 45 denotes a water level abnormal drop sensor, which closes the drain control electromagnetic valve 41 when the drainage of the electrolyzed water 37 is performed at a water level lower than the sewage sensor 43 at a lower L level. Reference numeral 46 denotes a drain valve for emptying the electrolytic cells 32 and 33, which is normally closed. Reference numeral 47 denotes a pump for extracting the electrolytic water 37 from the electrolytic cells 32 and 33. Reference numeral 48 denotes an electrolysis control device, which includes the electrolysis floating electrode F2, the water supply electromagnetic valve 36, the extraction control electromagnetic valve 41, the water level sensor 42, the sewage level sensor 43, the water level sensor 44, and the pump 44. Of the operating switches are connected.

The electrolysis device 31 having the above configuration is operated as follows by a control signal from the electrolysis control device 48. That is, ①: Water is supplied to each of the electrolytic cells 32 and 33. Water is supplied to the water level of the water level sensor 42 via the valve 36. ②: Floating electrode F2 for electrolysis of electrolyzers 32 and 33 is activated, electrolysis is performed for a predetermined time, and water becomes electrolyzed water 37 of carbon dioxide solution. ③: After that, open the electromagnetic valve 41 for extraction control of one electrolytic cell 32 and operate the pump 47 to extract the electrolyzed water 37 and spray it for plant growth. ④: With this use, the water level of the electrolyzed water 37 in the electrolysis tank 32 is lowered, but the electrolysis floating electrode F2 is lowered following the water level drop, so that stable electrolysis is performed. ⑤: When the water level falls below the sewage level sensor 43, the electromagnetic control valve for extracting the electrolytic cell 32 is closed by the control signal from the electrolysis controller and the electromagnetic valve 36 for supplying water to the electrolytic cell 32 is closed. It opens and water is supplied. At the same time, the electromagnetic valve 41 for controlling the extraction of the electrolytic cell 33 is opened, and the electrolytic water 37 can be extracted continuously. ⑥: Thus, the electrolytic cells 32 and 33 can be used alternately. In addition, by controlling the water level of the electrolyzed water 37 based on the control signal from the electrolysis control device 48 so as to balance the water supply and the drainage between the water level sensor 42 and the sewage level sensor 43, one of the electrolytic cells 32 ( Use of only 33) is possible. In addition, although two electrolytic tanks 32 were described as examples, the number of electrolytic tanks is not particularly limited, and the number of electrolytic tanks can be appropriately set to one or more depending on the implementation situation. As in the embodiment, two tanks are used alternately, and can be used by switching sequentially.

In the electrolysis apparatus 31 having the above configuration, a current stabilizing device and a polarity switch are interposed between the pair of electrodes i2 and 12 of the floating electrode F2 for electrolysis and the power supply, and these are connected to the electrolysis control device 48. Electrolysis can be performed by switching the polarity of the pair of electrodes 12, 12 at a desired cycle by a control signal from the electrolysis controller 48. By these electrolysis, electrolyzed water in which carbon dioxide for plant growth is dissolved can be obtained stably and efficiently.

As described above, according to the floating electrode for electrolysis according to the present invention, even if the liquid level changes due to a change in the amount of liquid to be electrolyzed, the liquid moves up and down following the fluctuation, Stable electrolysis can always be performed regardless of the level fluctuation. In the floating electrode for electrolysis according to the present invention, the positive and negative electrode pairs In addition to the above-mentioned effects, by providing the electrodes so that the distance between the facing surfaces of the electrodes gradually decreases, the electrodes during electrolysis can be consumed almost uniformly without collapsing or breaking. And the electrolysis efficiency can be improved. It is particularly effective for carbonaceous electrodes. Further, according to the electrolysis apparatus of the present invention, the water supply to the electrolysis tank and the extraction of the electrolyzed water after the electrolysis can be performed alternately and efficiently, so that the carbon dioxide solution sprayed for growing terrestrial plants can be efficiently used. Is obtained. In addition, by using the electrolysis floating electrode of the present invention in combination with the electrolysis apparatus of the present invention, it is possible to enjoy the function and effect of the electrolysis floating electrode and to obtain a stable electrolysis regardless of the fluctuation of the liquid level. The carbon dioxide solution sprayed for growing terrestrial plants can be obtained more efficiently. In addition, the concentration of carbon dioxide in the obtained electrolyzed water is always stable. By spraying such a carbon dioxide solution on terrestrial plants, photosynthesis of plants such as crops and horticultural plants is ensured. Training is achieved.

Claims

The scope of the claims

1. A floating electrode for electrolysis, characterized in that at least a pair of positive and negative electrodes are provided on a float.

2. Float force It consists of a top plate, a bottom plate, a column connecting the top plate and the bottom at four corners, and a float body attached to the side of the top plate. 2. The floating type electrode for electrolysis according to claim 1, further comprising a B through hole for passing through the electrode.

The cross section of the current introduction part of the electrode is formed larger than the cross section of the electrode part, and a through hole slightly larger than the cross section of the electrode part is formed in the float. 3. The floating electrode for electrolysis according to claim 1, wherein the electrode part of the electrode is inserted into the hole and the electrode is provided on the float.

4. The floating electrode for electrolysis according to claim 1, 2 or 3, wherein the floating electrode is formed of a plastic block with a strong float.

5. The floating electrode for electrolysis according to any one of claims 17 to 4, wherein the pair of positive and negative electrodes is provided such that the distance between the opposed surfaces of the electrodes gradually decreases toward the tip.

The floating electrode for electrolysis according to any one of claims 1 to 5, wherein only the anode of the pair of positive and negative electrodes is a carbonaceous electrode.

7. The floating electrode for electrolysis according to any one of claims 1 to 5, wherein both the positive and negative electrode pairs are carbonaceous electrodes.

8. Electrolytic carbonaceous electrode composed of 50 to 80% of carbonaceous material and 20 to 50% of thermosetting resin.

A floating electrode for electrolysis according to claim 6, wherein the carbonaceous electrode is the carbonaceous electrode for electrolysis according to claim 8.

10. The floating electrode for electrolysis according to claim 7, wherein the carbonaceous electrode is the carbonaceous electrode for electrolysis according to claim 8.

1 1. An electrolytic cell, a water supply pipe attached to the electrolytic cell for supplying water and a drain pipe for extracting electrolytic water, and at least an anode provided in the electrolytic cell for electrolyzing water. Characterized by comprising a pair of electrodes that are carbonaceous electrodes of

12. The electrolytic device according to claim 11, wherein the pair of electrodes is the electrolytic ffl floating electrode according to any one of claims 6 and 9.

13. The electrolytic device according to claim 11, wherein the pair of electrodes is the floating electrode for electrolysis according to any one of claims 7 and 10.

14. The electrolytic device according to claim 11, wherein the pair of electrodes is connected to a power supply through a current stabilizing device, and is connected to a zero electrolysis control device.

15. The electrolytic device according to claim 11, wherein the pair of electrodes is connected to a power supply via a current stabilizing device and a polarity switch, and is connected to an electrolysis control device.

If; a water level sensor is provided in the electrolytic cell, a control opening / closing valve is provided in each of the water supply pipe and the drainage pipe, and these are connected to the electrolysis control device, any one of claims 11 to 15; 1 Electrolytic equipment on your own.

17. The electrolytic device according to claim 11, wherein an electrolytic operation condition sensor is connected to the solution control device.

18. A method for growing a plant, comprising spraying a carbon dioxide solution produced by the electrolysis apparatus according to any one of claims 11 to 17 onto a land-based plant that mainly performs carbonic acid assimilation.

19. The method for growing plants according to claim 18, wherein the carbon dioxide solution is mainly sprayed on the leaves of the plants.