JP2002065089A - Method and apparatus for treating nutrient solution of cultivation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide both a method for treating a nutrient solution of cultivation capable of promoting growth of plant and preventing diseases in a low electric power consumption at a low cost since in a conventional method for treating a nutrient solution of cultivation, completely different two kinds of treatments have to be carried out so as to promote the growth of plant and to prevent diseases and the conventional method has a problem of requiring an electric power consumption and a cost and an apparatus for the method. SOLUTION: This method for treating a nutrient solution cultivation comprises allowing a nutrient solution of cultivation to flow into an electrolytic bath 2 equipped with carbon-based electrodes 21, subjecting the nutrient solution to a first electrode treatment for applying 0.9-1.8 V, preferably about 1.6±0.1 V voltage lower than a halogen decomposition voltage value to the nutrient solution, then allowing the nutrient solution to flow into an electrolytic bath 3 equipped with platinum-based compound electrodes 31 and subjecting the nutrient solution to a second electrode treatment for applying 1.5-3.0 V, preferably about 2.4 V voltage to the nutrient solution. This apparatus for carrying out the method is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for improving the quality of water of a cultivated nutrient solution used for hydroponics of plants, and more particularly to a cultivation capable of promoting plant growth and preventing disease. The present invention relates to a nutrient solution treatment method and a treatment device.

[0002]

2. Description of the Related Art When performing hydroponic cultivation, the nature of the nutrient solution has a great effect on the growth of plants. Usually water is H ₂ O
Hydrogen atoms (positively charged) of one water molecule are attracted to oxygen atoms (negatively charged) of another water molecule by electric force, and at least 5 molecules called clusters It is thought to exist as a group.

[0003] It is considered that water having different cluster sizes also has different properties (Ref. 1;
Kazuhiro Matsushita, Journal of Food Industry, 2, 28, 1992), it is estimated that small cluster water promotes plant growth because it is easily absorbed by plant cells and tissues (Ref. 2; Masaki Matsuo et al., Agriculture and horticulture, 70, 4, 1995).

In addition, the oxidation-reduction potential (ORP; oxidation-
reduction potential) is also known to affect plant growth. Acid water, which has a high oxidation-reduction potential and strong oxidizing power, has a bactericidal effect due to the oxidizing effect, but it may damage plant cells and hinder growth, but alkaline water with a low oxidation-reduction potential is reduced. It is considered that the growth of plants is promoted by reducing and normalizing the peroxidation state by force (Reference Document 2).

[0005] It is also known that when the dissolved oxygen concentration in the cultivated nutrient solution is high, high-temperature oxygen deficiency in summer can be eliminated and the growth of plants is promoted.

That is, for promoting the growth of plants, cultivation nutrient solutions having small clusters, low oxidation-reduction potential, and high dissolved oxygen concentration are suitable. Further, in order to prevent plant diseases, it is necessary to kill microorganisms in nutrient solutions.

[0007] For this reason, conventionally, for the purpose of promoting the growth of plants and preventing diseases, treatment for improving the properties of cultivation nutrient solutions used for hydroponics of plants has been performed.

[0008] Conventional methods for treating cultivation nutrient solutions for the purpose of promoting growth include a magnet treatment method, an electrolytic water addition method, and the addition of hydrogen peroxide (H ₂ O ₂ ). The magnet treatment method magnetically treats a cultivation nutrient solution by using a high-field magnet, and aims at promoting growth by reducing clusters of the cultivation solution.

The electrolytic water addition method reduces the cluster of the cultivation nutrient solution and reduces the oxidation-reduction potential. The addition of hydrogen peroxide increases the concentration of dissolved oxygen in the cultivation nutrient solution.

As a conventional method of treating a cultivated nutrient solution for the purpose of disease prevention, an ultraviolet irradiation method and a method of adding a drug such as a chlorine-based substance or ozone are used.

[0011] Separately, a method of electrochemically disinfecting microorganisms by electrode treatment has been studied (Ref. 3; T. Matsunaga, Anal. Chem., 56, 798, 1984). In this method, it is considered that the cell is killed by an electrode reaction occurring between the cell and an electrode in contact with the cell. Specifically, electron transfer occurs between CoA in the cell and the electrode, which oxidizes CoA and disables metabolism involving CoA (energy generation in the citric acid cycle, etc.). It is thought to die. In addition, according to Reference 3, it is reported that when a voltage of 0.9 V or more is applied, a bactericidal effect against most bacterial species can be obtained.

Further, application of the sterilization method using the electrode treatment to the piping system of a factory or the prevention of marine organism adhesion in a marine environment has been studied (Reference 4; Matsunaga, et al.,
"Electrochemical sterilization and its application", Biotechnology, vol.77,23
2).

Further, it is also known that the oxidation-reduction potential is lowered by the electrode treatment, which is caused by the electromagnetic force generated by the electrode to which the voltage is applied, as in the case of the magnetic field treatment.
It is estimated that trace amounts of O ₂ ⁻ and OH ⁻ are generated in the liquid (Ref. 5; Gozo Matsuzaki, Development and Application of Functional Water, Technical Information Center Publishing Co., Ltd., September 1999).
Month).

[0014] As a prior art relating to the treatment of a culture solution for plant cultivation, Japanese Patent Application Laid-Open No. Hei 10-1998 published on February 17, 1998 is disclosed.
No. 42728, “Plant cultivation method and plant cultivation apparatus” (applicant: Idemitsu Kosan Co., Ltd. and others; inventor: Yoshio Shiba et al.). This conventional technique is an oscillating electric field, preferably a high-frequency oscillating electric field, and a plant cultivation method and a plant cultivation apparatus for supplying water or culture solution to a plant to which an oscillating electric field whose electric field intensity periodically changes at a low frequency is applied. Yes, it can promote the growth of plants and stably provide the growth promoting effect.

[0015]

However, the conventional methods for treating a cultivating nutrient solution have only one effect of promoting growth or disinfecting. Therefore, in order to obtain both effects of promoting growth and disinfecting, It is necessary to perform two completely different processes, and there is a problem that the process is complicated and the cost is increased.

In addition, the conventional ultraviolet irradiation method consumes a large amount of electric power and can sterilize only the surface of the cultivation nutrient solution. Further, when a colored component such as chelate iron is added, ultraviolet rays are absorbed by the colored component and the sterilizing effect is improved. There is a problem that the temperature is significantly reduced.

Further, in the above-mentioned conventional drug addition method, although the bactericidal effect is high, the maintenance cost is high. In particular, when a chlorine-based substance is added, it is necessary to remove the chlorine-based substance remaining after sterilization by filtration. However, there was a problem that it became high.

The present invention has been made in view of the above circumstances, and provides a method and apparatus for cultivating nutrient solution capable of promoting plant growth and preventing disease with low power consumption and low cost. With the goal.

[0019]

SUMMARY OF THE INVENTION The present invention for solving the above-mentioned problems of the prior art comprises a method for treating a cultivated nutrient solution,
A voltage of 0.9 to 3.0 V is applied to a carbon-based or platinum-based compound electrode, and a cultivation nutrient solution is directly contacted with the electrode to perform electrode treatment, without adding a drug or irradiating ultraviolet rays. The cultivation nutrient solution can be sterilized, the clusters can be reduced, the oxidation-reduction potential can be reduced, plant growth can be promoted and disease can be prevented, and power consumption and cost required for treatment can be reduced.

Further, according to the present invention, a voltage of 0.9 to 3.0 V is applied to a plurality of carbon-based electrodes or a plurality of platinum-based compound electrodes, and the cultivation solution is directly applied to the plurality of carbon-based electrodes or the platinum-based compound electrodes. , A method of treating a cultivation nutrient solution that performs multi-electrode treatment, making it easier for microorganisms to contact the electrode surface,
The bactericidal effect can be improved.

Further, the present invention is a method for treating a cultivating nutrient solution in which the voltage applied to the carbon-based electrode is lower than the halogen decomposition voltage, and the cultivating nutrient solution can be sterilized without generating residual chlorine. In addition, the cost required for removing residual chlorine can be eliminated.

The present invention also provides an electrolytic cell provided with a carbon-based electrode which is applied with a voltage of 0.9 to 1.8 V and performs electrode treatment in contact with a cultivating nutrient solution that has flowed in, or an electrolytic cell provided with a carbon electrode of 1.5 to 1.8 V. 3.0V
Voltage is applied, and it is a processing device for cultivating nutrient solution having an electrolytic tank provided with a platinum-based compound electrode that performs electrode treatment in contact with the cultivating nutrient solution that has flowed in. Disinfects the solution, reduces clusters, reduces redox potential, and increases the concentration of dissolved oxygen in the cultivated nutrient solution, allowing simple equipment to promote plant growth and prevent disease and consume Power and cost can be reduced.

The present invention also provides an electrolytic cell having a plurality of carbon-based electrodes to which a voltage of 0.9 to 1.8 V is applied and which performs a multi-electrode treatment by coming into contact with a cultivating nutrient solution which has flowed in. .5-
Since a voltage of 3.0 V is applied to the cultivation nutrient solution having an electrolytic cell provided with a plurality of platinum-based compound electrodes for performing multi-electrode treatment by contacting the cultivation nutrient solution that has flowed in, the microorganisms are used as electrodes. The surface can be easily contacted, and the sterilizing effect can be improved.

In the present invention, the first electrode treatment is performed by applying a voltage to the carbon-based electrode to perform electrode treatment on the cultivation nutrient solution, and applying a voltage to the platinum-based compound electrode. It is a method of processing a cultivation nutrient solution that performs a second electrode treatment of performing an electrode treatment of the cultivation nutrient solution that has been performed.
A series of treatments that sterilize the cultivation nutrient solution without adding chemicals or irradiate ultraviolet rays, reduce clusters, reduce oxidation-reduction potential, and increase the concentration of dissolved oxygen in the cultivation nutrient solution by the second electrode treatment. This can promote plant growth and prevent disease, reduce power consumption and cost required for the treatment, and generate water electrolysis by performing a second electrode treatment after the first electrode treatment. The reaction between hydrogen peroxide and the carbon electrode can be prevented.

The present invention also provides a first electrolytic cell for applying a voltage to a carbon-based electrode to electrode-treat a cultivation solution, and a voltage for applying a voltage to a platinum-based compound electrode to flow from the first electrolytic cell. A cultivating nutrient solution processing device including a second electrolytic cell for electrode-treating a cultivating nutrient solution to be sterilized without adding chemicals or irradiating ultraviolet rays, reducing the size of clusters, and reducing oxidation and reduction. Reduce the potential, increase the dissolved oxygen concentration in the cultivation nutrient solution, with a simple device, can promote plant growth and prevent disease, reduce power consumption and cost,
Further, by performing the second electrode treatment after the first electrode treatment, it is possible to prevent the reaction between hydrogen peroxide generated by the electrolysis of water and the carbon electrode, and to carry out the two treatments with the same apparatus. By doing so, it is possible to increase the efficiency of processing and to effectively use space.

Further, the present invention provides an electrolytic cell provided with a carbon-based electrode, in which a plurality of net-like carbon-based electrodes are arranged one on top of the other in the direction in which the cultivating nutrient solution flows, and the electrode of the plurality of arranged carbon-based electrodes is provided. The surface is arranged so as to be perpendicular to the direction in which the cultivation nutrient solution flows, and the cultivation nutrient solution as a first electrolytic cell to which a positive or negative voltage is alternately applied to each of the arranged carbon-based electrodes. Since the treatment device is used, the contact area between the cultivation nutrient solution and the carbon electrode is increased, the microorganisms can be easily brought into contact with the electrode, and the bactericidal effect can be improved.

[0027]

Embodiments of the present invention will be described with reference to the drawings. The method and apparatus for treating a cultivation nutrient solution according to the present invention include an electrode treatment in which a voltage of 0.9 to 3.0 V is applied to a carbon-based electrode or a platinum-based compound electrode to bring the cultivation nutrient solution into direct contact with the electrode. The purpose is to sterilize the cultivation nutrient solution without adding chemicals or irradiating ultraviolet rays, to reduce clusters, reduce oxidation-reduction potential, promote plant growth and prevent disease.

Next, a method (the present method) and a processing apparatus (the present apparatus) of the cultivating nutrient solution according to the embodiment of the present invention will be described. The method for treating a cultivation nutrient solution (the present method) and the treatment apparatus (the present apparatus) according to the embodiment of the present invention are performed by combining an electrode treatment using a carbon-based electrode and an electrode treatment using a metal-based electrode. With low power consumption and low cost,
Cultivating nutrient solution such as cultivating nutrient solution and irrigation water can be made into small clusters to reduce the oxidation-reduction potential, increase dissolved oxygen concentration, and further sterilize to promote plant growth and prevent disease.

The electrode treatment of the present method includes sterilization of the cultivation nutrient solution and
A first treatment for reducing the clustering and the oxidation-reduction potential, and a second treatment for increasing the dissolved oxygen concentration by electrolyzing water.
And the processing of. Note that the first processing and the second processing may be performed independently, but a method and an apparatus combining the first processing and the second processing will be described here.

Here, the carbon electrode is the most suitable electrode material for obtaining a sterilizing effect, but it is liable to react with hydrogen peroxide generated by the electrolysis of water. It is inappropriate to use it as an electrode in the second treatment. In addition, it is not preferable to perform the sterilization or the like after first performing the electrolysis of water to increase the dissolved oxygen concentration by changing the order of the first treatment and the second treatment, for the same reason.

Therefore, in the present method, a first electrode treatment using a carbon-based electrode (carbon electrode) is performed to reduce clusters, reduce the oxidation-reduction potential, further sterilize, and Water is electrolyzed by a second electrode treatment using an electrode to increase the dissolved oxygen concentration in the cultivation nutrient solution. Thus, the hydrogen peroxide generated in the second processing does not react with the carbon electrode.

As described in the prior art, it is known that the electrode treatment of a cultivating nutrient solution can provide the effects of clustering, reduction of oxidation-reduction potential, increase of dissolved oxygen concentration, and sterilization. . However, the water for adjusting the cultivation nutrient solution is generally natural water such as groundwater, rainwater, river water, etc. These natural waters contain chlorine ions (Cl ⁻ ) and contain water containing chlorine ions. When the electrode process, the reaction was chlorine ions is residual chlorine as follows at the anode (ClO ^-)
Could be _{^{2Cl - → Cl 2 + 2e -}} Cl 2 + H 2 O → ClO - + 2H + + Cl -

It is known that when the residual chlorine concentration in the cultivated nutrient solution increases, the cultivated plant is harmed. At the laboratory level, it has been shown that cultivated plants suffer root damage when the residual chlorine concentration is 0.2-0.5 ppm (Ref. 6; edited by Masaki Takatsuji, Plant Factory Handbook, 1997, Tohoku University Press) ).

Therefore, in order to sterilize or increase the concentration of dissolved oxygen by performing electrode treatment of the cultivation nutrient solution, it is necessary to control the electrode material and applied voltage so that the desired effect can be obtained while suppressing the generation of residual chlorine. Processing conditions need to be optimized.

Since residual chlorine is generated when a voltage higher than the halogen (chlorine) decomposition voltage is applied, the electrode treatment of the cultivation nutrient solution must be performed at a voltage lower than the halogen decomposition voltage. In general, the halogen decomposition voltage varies depending on conditions such as various electrode materials, halogen (chlorine) ion concentration, and solution temperature.

As a result of experiments, the present inventors have found that the halogen decomposition voltage when a voltage is applied using a carbon electrode is higher than the halogen decomposition voltage when a metal electrode is used, and that residual chlorine is less likely to be generated. It was confirmed.

An experimental example will be specifically described. The results of measuring the decomposition voltage of a halogen compound (chloride) at various chlorine ion concentrations using a carbon electrode and two kinds of metal-based electrodes will be described with reference to FIGS. 1, 2, and 3. FIG.
FIG. 1 is a graph showing the decomposition voltage of an HCl distilled aqueous solution when a carbon electrode is used, and FIG. 2 is a graph showing the decomposition voltage of an HCl distilled aqueous solution when a platinum-based Exerode BA electrode is used. In addition, FIG. 3 is a graph showing the decomposition voltage of a distilled HCl aqueous solution when an Exerode R-2000 electrode is used.

In the examples shown in FIGS. 1 to 3, a decomposition aqueous solution of HCl, which is a strong electrolyte which is easily decomposed, was prepared, a voltage was applied using a carbon electrode, and the decomposition voltage was measured. The concentration of the distilled aqueous solution of HCl is 39 ppm, the average concentration of chlorine ions in groundwater.
And the upper limit 100 ppm and the lower limit 4 ppm of the chloride ion concentration of natural water including rainwater, river water, etc., were measured. The electrode area is 170 cm ² × 2, and the electrode spacing is 2
3 mm.

As shown in FIG. 1, when the HCl concentration increases, the decomposition voltage tends to decrease, and the decomposition tends to occur. When the chlorine ion concentration is 100 ppm at room temperature, it can be seen that the decomposition voltage is about 2 V (volt) when a carbon electrode is used.

2 and 3, the decomposition voltage was approximately 1.5 V when a platinum-based Exerode BA electrode and an Exerode R-2000 electrode were used.

Here, as described in the prior art, in the electrochemical sterilization method, when a voltage of 0.9 V or more is applied, the effect of sterilization can be recognized for most bacterial species. Therefore,
Carbon electrode, Platinum Exelode BA electrode, Exelord R-
It is possible to sterilize microorganisms without generating residual chlorine using any of the 2000 electrodes. However, considering the process margin, halogen compounds (HCl)
The carbon electrode with the highest decomposition voltage is considered optimal. From the above, in the present method, the first electrode treatment was performed using the carbon electrode to achieve small clustering of hydroponic water, reduction of the oxidation-reduction potential, and sterilization.

Next, the present inventors examined the processing voltage in consideration of the liquid temperature.
It has been confirmed that 9 to 1.8 V is appropriate, and about 1.6 (± 0.1) V is desirable. Here, an experimental example will be specifically described. The effect of the liquid temperature on the decomposition voltage of the halogen compound will be described with reference to FIG. FIG. 4 is a graph showing the decomposition voltage of a 100 ppm HCl distilled water solution when the liquid temperature is changed using a carbon electrode.

When performing hydroponic cultivation, the liquid temperature changes depending on the season, which may affect the decomposition voltage of the halogen compound. Therefore, at 40 ° C. and 10 ° C. using a carbon electrode.
The decomposition voltage of 100 ppm HCl distilled water solution at two liquid temperatures of ° C. was measured. The electrode area was 170 cm ² × 2, and the electrode spacing was 2-3 mm.

As shown in FIG. 4, when the liquid temperature is 40 ° C., the decomposition voltage of a 100 ppm HCl distilled aqueous solution using a carbon electrode is about 1.8 V, and when the liquid temperature is 10 ° C., it is about 2.1 V. Was. Further, as shown in FIG. 1, the voltage was about 2 V at room temperature. Therefore, considering the summer when the liquid temperature rises,
Electrode treatment must be performed at a voltage of less than 1.8V,
Further, in view of the process margin, 0.9 to 1.8 V is appropriate, and particularly, about 1.6 (± 0.1) V is desirable.

Therefore, the processing conditions of the first electrode treatment in the present method are such that the electrode treatment is carried out using a carbon electrode at a voltage lower than the halogen decomposition voltage, preferably 1.6 ± 0.1 V, and the treatment time (cultivation and cultivation) The contact time between the liquid and the electrode) is preferably about 20 minutes or more in order to ensure the sterilization effect.

Since the decomposition voltage of water when a carbon electrode is used is about 2.5 V, water electrolysis does not occur at 1.6 V, and the above-mentioned reaction between the carbon electrode and hydrogen peroxide does not occur. Since this does not occur, 1.6 V is appropriate as an electrode processing voltage using a carbon electrode.

Next, the present inventors examined the conditions of the second electrode treatment for increasing the dissolved oxygen concentration, and found that a platinum compound electrode, Exelode, was used as the electrode material.
It was confirmed that a BA electrode was appropriate, and that a processing voltage of about 2.4 V was optimal when this electrode was used.

Here, the experimental results will be specifically described. As described above, since the carbon electrode is not suitable for the purpose of generating oxygen, the suitability of the platinum-based Exerode BA electrode and Exerode R-2000 electrode was examined. The cultivation nutrient solution having a Cl ^- ion concentration of 100 ppm was subjected to electrode treatment by changing the applied voltage between two kinds of electrodes, and the dissolved oxygen concentration and the residual chlorine concentration were measured. The processing flow rate was set to a low flow rate of 100 ml / min to facilitate the measurement. The electrode area was 340 cm ² , and the electrode interval was 3 mm.

The examination result of the oxygen generating electrode will be described with reference to FIG. FIG. 5 is a graph showing the concentration of dissolved oxygen and the concentration of residual chlorine in each of the platinum-based Exelode BA electrode and Exelord R-2000 electrode when the electrode treatment was performed while changing the applied voltage. As shown in FIG. 5, both the Exerode BA electrode and the Exerode R-2000 electrode tend to increase the residual chlorine concentration and the dissolved oxygen concentration when the applied voltage increases. The dissolved oxygen concentration did not show a large difference between the two electrodes, and increased similarly, but the residual chlorine concentration increased less with the Exerode BA electrode.

In the case of the Exelode BA electrode, when a voltage of 2.6 V is applied, the dissolved oxygen concentration increases from 8.3 ppm to 9.5 ppm, and the residual chlorine concentration increases only by 0.11 ppm. It is considered that the load BA electrode is suitable as an electrode for treating a culture nutrient solution. Therefore, in this method, an Exerode BA electrode is used as the second electrode treatment.

The processing voltage of the second electrode processing is as shown in FIG. 5 when the Exerode BA electrode is used.
In the range of 1.5 to 3.0 V, it is possible to increase the dissolved oxygen concentration while suppressing the increase in the residual chlorine concentration. More preferably, the dissolved oxygen concentration is about 2.2 to 2.8 V, and ideally about 2 to 2.8 V. .4
About V.

Here, an Exerode BA electrode was used as an example of the platinum-based compound electrode. However, the present invention is not limited to this, and the generation of residual chlorine is small. Any other electrode may be used as long as it increases the electrode material.

That is, the present method is applied to a culture solution.
First, using a carbon-based electrode, less than the halogen decomposition voltage, that is, 0.9 to 1.8 V, preferably 1.6 V ± 0.1.
A voltage of about V is applied to perform a first electrode treatment in which the contact time between the cultivation nutrient solution and the electrode is about 20 minutes or more, and then a platinum-based compound electrode such as an Exerode BA electrode is used. 1.5 to 3.0 V, preferably 2.2 to 2.8
The second electrode treatment for applying a voltage of about V is performed.

In the present method, the first electrode treatment can reduce the cluster of the cultivation nutrient solution, reduce the oxidation-reduction potential, and further sterilize the cultivation solution. The dissolved oxygen concentration in the liquid can be increased, and both effects of promoting plant growth and preventing disease can be obtained.

Even if only the first electrode treatment is carried out, the effects of sterilization, small clustering and reduction of redox potential can be obtained, so that both effects of promoting growth and preventing disease can be obtained. When the second treatment for increasing the concentration of dissolved oxygen is performed in combination, a great effect is obtained in preventing oxygen deficiency in summer, and the effect of promoting growth is remarkable.

Further, in the first electrode treatment, the cultivation nutrient solution can be sterilized without adding a drug, and thus is particularly suitable for the treatment of hydroponic water used for cultivation of edible plants. It is also excellent in that addition of a colored component such as chelated iron does not affect the bactericidal effect.

Next, an apparatus for cultivating nutrient solution (this apparatus) for realizing the above-described method for treating hydroponic water (this method) according to the embodiment of the present invention will be described with reference to FIG. FIG.
1 is a schematic configuration diagram of a cultivation nutrient solution treatment device according to an embodiment of the present invention. As shown in FIG. 6, the present apparatus comprises a tank 1 for storing untreated cultivation nutrients, an electrolytic tank 2 for performing a first electrode treatment, an electric field tank 3 for performing a second electrode treatment, and a cultivation nutrient solution. The pump comprises a pump 4 for pressurizing the cultivated nutrient solution so as to flow through the processing apparatus at a constant flow rate, and a tank 5 for storing the processed cultivated nutrient solution.

Further, a plurality of carbon-based electrodes 21-1 to 21-n for performing the first electrode treatment are provided in the electrolytic cell 2 as described above.
Is provided, and a positive or negative voltage is alternately applied to the carbon-based electrode 21. In the example of FIG.
, 21-n are anodes to which a positive voltage is applied, and carbon-based electrodes 21-2, 21-4, ... are cathodes to which a negative voltage is applied.

In order to sterilize microorganisms, it is necessary that the electrodes and the microorganisms come into contact with each other to transfer electrons. Therefore, in the present apparatus, in order to increase the contact area between the cultivation nutrient solution and the carbon electrode, the carbon-based electrode 21 is a net electrode formed in a net shape.

Further, as shown in FIG. 6, a plurality of carbon-based electrodes 21 are vertically stacked so that each electrode surface is parallel to each other, so that microorganisms can be surely applied to the carbon-based electrodes 21. They are killed by contact. In addition, by using a mesh electrode, even if a plurality of carbon-based electrodes 21 are stacked, the weight can be reduced.

The platinum layer electrodes 31a and 31a for electrolyzing water as a second electrode treatment are provided on the electrolytic layer 3.
b is provided, a positive voltage is applied to the platinum-based electrode 31a, and a negative voltage is applied to the platinum-based electrode 31b. Here, an Exerode BA electrode is used as the platinum-based electrodes 31a and 31b based on the above-described experimental results. However, any electrode may be used in which the dissolved oxygen concentration is increased, the generation of residual chlorine is small, and the electrodes themselves do not react. Any other electrode material may be used.

In the apparatus having the above configuration, the tank 1
The untreated cultivation nutrient solution stored in the tank flows out from a water outlet provided at the lower part of the tank via a pipe, is pressurized by a pump 4, and passes through the electrolytic cells 2 and 3 at a constant flow rate. Here, in order to ensure the sterilization effect, the flow rate is adjusted by the pump 4 so that the processing time in the electrolytic cell 2 becomes about 20 minutes.

In the electrolytic cell 2, when the cultivating nutrient solution passes through the mesh of the carbon-based electrode 21, microorganisms and bacteria in the cultivating nutrient solution contact the carbon-based electrode 21 and die. At the same time, the electromagnetic force generated by the electrodes reduces water clusters and further reduces the oxidation-reduction potential.

At this time, if the voltage applied to the coalbed electrode 21 is maintained at 1.6 V ± 0.1 V, a sufficient sterilizing effect can be obtained and the generation of residual chlorine can be suppressed within an allowable range. . Also, when the liquid temperature is low, such as in winter,
When the voltage applied to the carbon electrode is less than the halogen decomposition voltage, 1.6
V may be set higher to increase the processing efficiency.

Then, the cultivation nutrient solution having a sterilized, small cluster, and reduced oxidation-reduction potential flows into the electrolytic cell 3 from an outlet provided at the upper part of the electrolytic cell 2, and the platinum-based electrode 31 is formed.
Pass between a and 31b. At this time, when a voltage is applied to the platinum-based electrodes 31a and 31b, electrolysis of water occurs, and oxygen is generated to increase the dissolved oxygen concentration in the cultivation nutrient solution.

As described above, when the voltage applied to the platinum-based electrode 31 is set to 2.4 V, the dissolved oxygen concentration is sufficiently increased, and the generation of residual chlorine can be suppressed to be within the allowable concentration. is there.

The cultivated nutrient solution treated in the electrolytic cell 2 and the electric field tank 3 is stored in a tank 5 and used as a cultivated nutrient solution for plant cultivation and water. In addition, you may make it flow out to a culture container of a plant as it is, without storing the processed liquid in the tank 5.

According to the method and the apparatus for treating a cultivating nutrient solution according to the embodiment of the present invention, the cultivating nutrient solution flows into the electrolytic cell 2 provided with the carbon electrode, and the cultivating nutrient solution is supplied to the electrolytic cell 2 having a carbon decomposition voltage of less than 0.1. The first electrode treatment is performed by applying a voltage of about 9 to 1.8 V, preferably about 1.6 ± 0.1 V, and then flows into the electrolytic cell 3 provided with a platinum-based compound electrode, and is subjected to 1.5 to 1.5 V. 3.0V
, And preferably a voltage of 2.2 to 2.8 V is applied, so that the first electrode treatment reduces water clusters and reduces the oxidation-reduction potential to some extent. However, the growth of the plant can be promoted by increasing the dissolved oxygen concentration by the second electrode treatment, and the cultivation nutrient solution can be sterilized by the first electrode treatment to prevent the disease of the plant. effective.

Further, according to the present method and the present apparatus, since both the first processing and the second processing are electrode processing, the apparatus configuration and the flow of the processing can be reduced as compared with the case where ultraviolet irradiation or drug administration is performed. It can be simplified and has the effect of reducing costs.

Further, according to the present method and the present apparatus, since the processing voltage is only several volts, the power consumption can be greatly reduced as compared with the case of irradiation with ultraviolet rays, and the maintenance of the apparatus is easy. And cost can be reduced.

Further, according to the present apparatus, the carbon-based electrode 21 in the electrolytic cell 2 for performing the first electrode treatment is used as a mesh electrode, and the plurality of carbon-based electrodes 21 are connected so that the cultivation nutrient solution passes through the plurality of electrodes. Since the electrode surfaces are parallel to each other and are stacked along the flow of the culture nutrient solution, the contact area between the culture nutrient solution and the carbon-based electrode 21 is increased, so that microorganisms and bacteria can be easily brought into contact with the electrode. There is an effect that the sterilization effect can be improved.

Further, by using the carbon-based electrode 21 in the electrolytic cell 2 as a mesh electrode, there is an effect that the weight can be reduced and the apparatus can be easily moved and installed.

Further, when it is not necessary to increase the dissolved oxygen concentration in a low temperature environment, the electrolytic cell 3 is removed and the electrolytic cell 2 is removed.
It is also possible to carry out the treatment only with the electrolytic cell 3, and the electrolytic cell 3 can be easily attached and detached as necessary, which is convenient and can further reduce the power consumption.

The first processing and the second processing can obtain the effect even if they are performed independently. However, by performing the processing in combination, it is possible to increase the processing efficiency, reduce the apparatus cost, and effectively use the space. There is an effect that can be achieved.

[0075]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present method and the present apparatus will be described. Nutrient solution for plant cultivation with sterile distilled water (Toyo Kosan Co., Ltd., concentrated solution for vegetable cultivation solution, EC; 2.0 ms / cm, liquid temperature about 21
C.), and cultured E. coli (JM105) and the like were mixed into the prepared nutrient solution for plant cultivation.

Using the above-described apparatus, 1. an electrolytic cell (first electrolytic cell) for performing the first electrode treatment is provided between the carbon-based electrodes.
A constant voltage of 6 (± 0.1 V) was applied, and the culture solution was treated at a flow rate of 37 ml / min.

Further, the cultivation nutrient solution treated in the first electrolytic cell flows into an electrolytic cell (second electrolytic cell) for performing the second electrode treatment, and an Excello BA electrode is used as a platinum-based compound electrode. The second electrode treatment was performed by applying a constant voltage of 2.4 V between the electrodes.

The cultivated nutrient solution before and after the treatment was measured and evaluated by the method described below. First, magnetic resonance oxygen nucleus the culture solution before and after the treatment ⁽¹⁷ O-NMR) was evaluated by spectrophotometry. As the magnetic resonance apparatus, AL-400 manufactured by JEOL was used. Table 1 shows the results obtained by ¹⁷ O-NMR spectroscopy.

[0079]

[Table 1]

In general, when ¹⁷ O-NMR spectroscopy of various kinds of water is performed, the smaller the cluster, the narrower the spectrum line width of the ¹⁷ O-NMR spectroscopy, and the larger the cluster, the wider the spectrum line width. . As shown in Table 1, the line width of the cultivation nutrient solution spectrum was 78 Hz before the treatment.
However, after electrode treatment using the present method and the present apparatus, 48
Hz, which revealed that the size of the nutrient solution after treatment became smaller.

Next, the number of bacteria was measured by a plate colony culturing method for samples of the cultivated nutrient solution before and after the treatment. Table 2 shows the change in the bacterial concentration in the cultivation nutrient solution before and after the treatment in the first electrolytic cell and the sterilization rate.

[0082]

[Table 2]

As shown in Table 2, the bactericidal effect against Escherichia coli (JM105) mixed in the cultivation nutrient solution was as high as 97.3%.

Next, the dissolved oxygen concentration of the sample of the cultivated nutrient solution before the treatment and the sample of the cultivated nutrient solution after the second electrode treatment were measured by a dissolved oxygen meter (HORIBA D-25 type). Table 3 shows the dissolved oxygen concentration of the cultivation nutrient solution before the treatment and the cultivation nutrient solution after the second electrode treatment.

[0085]

[Table 3]

As shown in Table 3, it was confirmed that the concentration of dissolved oxygen was increased by the second electrode treatment.

Next, the pH of the culture nutrient solution sample before and after the treatment was measured.
Value (using HORIBA F-22 type pH meter), electrical conductivity (using YOKOVGAWA, MODEL SC82 EC meter), oxidation-reduction potential (using HORIBA F-22 type ORP meter) The basic technical index of the cultivation nutrient solution was measured. Table 4 shows the measured values of the pH value, electric conductivity, and oxidation-reduction potential of the cultivation nutrient solution before and after the treatment.

[0088]

[Table 4]

As shown in Table 4, before and after the treatment,
Although there was no significant difference in pH value and electrical conductivity, the oxidation-reduction potential was reduced to some extent.

From these evaluations, when the cultivation nutrient solution is treated by the present method and the present apparatus, water is made into small clusters by the first electrode treatment, the oxidation-reduction potential is reduced, and the dissolved oxygen concentration is decreased by the second electrode treatment. Can be increased, whereby plant growth can be promoted.

According to the present method and the present apparatus, the cultivation nutrient solution can be sterilized by the first electrode treatment to prevent plant diseases.

[0092]

According to the present invention, a voltage of 0.9 to 3.0 V is applied to a carbon-based or platinum-based compound electrode,
Since the cultivation nutrient solution is treated by directly contacting the cultivation nutrient with the electrode to perform the electrode treatment, the cultivation nutrient solution is sterilized without adding a chemical or irradiating ultraviolet rays, and the clusters are reduced to reduce the oxidation-reduction potential. Thus, plant growth promotion and disease prevention can be achieved, and the power consumption and cost required for treatment can be reduced.

Further, according to the present invention, a voltage of 0.9 to 3.0 V is applied to a plurality of carbon-based electrodes or a plurality of platinum-based compound electrodes, and the cultivation nutrient solution is directly applied to the plurality of carbon-based electrodes or platinum-based electrodes. Since the method is a method for treating a cultivation nutrient solution in which a multi-electrode treatment is performed by contacting with a compound electrode, there is an effect that microorganisms can be easily brought into contact with the electrode surface and a bactericidal effect can be improved.

Further, according to the present invention, since the cultivation nutrient solution is treated in such a manner that the voltage applied to the carbon-based electrode is lower than the halogen decomposition voltage, the cultivation nutrient solution is sterilized without generating residual chlorine. This has the effect of eliminating the cost required for removing residual chlorine.

Further, according to the present invention, 0.9 to 1.8 V
Voltage is applied, and an electrolytic cell provided with a carbon-based electrode for performing electrode treatment by contacting the grown nutrient solution or 1.5 to
A voltage of 3.0 V is applied, and the apparatus is a cultivating nutrient solution treatment apparatus having an electrolytic tank provided with a platinum-based compound electrode that performs electrode treatment by contacting with the infused cultivating nutrient solution. To sterilize cultivation nutrients without reducing the size of clusters, reduce oxidation-reduction potential, and increase the concentration of dissolved oxygen in cultivation nutrients, to promote plant growth and prevent disease with simple equipment This has the effect of reducing power consumption and cost.

According to the present invention, the first electrode treatment is performed by applying a voltage to the carbon-based electrode to apply electrode treatment to the cultivation nutrient solution and applying a voltage to the platinum-based compound electrode. Since the method is a method of treating a cultivation nutrient solution in which a second electrode treatment is performed to perform an electrode treatment of the cultivation nutrient solution, the first electrode treatment sterilizes the cultivation nutrient solution without adding chemicals or irradiating ultraviolet rays. The clusters are reduced, the oxidation-reduction potential is reduced, the concentration of dissolved oxygen in the cultivation nutrient solution is increased by the second electrode treatment, and a series of treatments can promote plant growth and prevent disease. The required power consumption and cost can be reduced, and further, by performing the second electrode treatment after the first electrode treatment, it is possible to prevent the reaction between hydrogen peroxide generated by the electrolysis of water and the carbon electrode. is there.

Further, according to the present invention, a first electrolytic cell for applying a voltage to a carbon-based electrode to electrode-treat a cultivating nutrient solution, and a first electrolytic cell for applying a voltage to a platinum-based compound electrode. And a second electrolytic cell for electrode-treating the cultivation nutrient flowing from the cultivation nutrient, so that the cultivation nutrient can be sterilized without adding chemicals or irradiating ultraviolet rays, and the cluster can be reduced. By reducing the oxidation-reduction potential and increasing the dissolved oxygen concentration in the cultivation nutrient solution, it is possible to promote plant growth and prevent disease with a simple device, reduce power consumption and cost, and By performing the second electrode treatment after the electrode treatment of the above, it is possible to prevent the reaction between hydrogen peroxide generated by the electrolysis of water and the carbon electrode, and to perform the two treatments in the same apparatus. Efficient processing and effective use of space There is an effect that can Rukoto.

Further, according to the present invention, in an electrolytic cell provided with a carbon-based electrode, a plurality of net-like carbon-based electrodes are arranged so as to overlap with each other in a direction in which a cultivating nutrient solution flows, and a plurality of arranged carbon-based electrodes are arranged. The electrode surface is arranged so as to be perpendicular to the direction in which the cultivation nutrient solution flows, and the cultivation nutrient solution treatment device in which a positive or negative voltage is alternately applied to each of the arranged carbon-based electrodes. This has the effect of increasing the contact area between the cultivation nutrient solution and the carbon electrode, making it easier for microorganisms to come into contact with the electrode, and improving the bactericidal effect.

[Brief description of the drawings]

FIG. 1 is a graph showing the decomposition voltage of a distilled HCl aqueous solution when a carbon electrode is used.

FIG. 2 HC using platinum-based Exelode BA electrode
It is a graph which shows the decomposition voltage of 1 distilled water solution.

FIG. 3 HCl using Exerode R-2000 electrode
It is a graph which shows the decomposition voltage of a distilled aqueous solution.

FIG. 4 100 pp when liquid temperature is changed using a carbon electrode
FIG. 3 is a graph showing the decomposition voltage of a distilled aqueous solution of mHCl.

Fig. 5 Platinum Exelode BA electrode and Exelord R-
FIG. 4 is a graph showing the dissolved oxygen concentration and the residual chlorine concentration when electrode treatment was performed for 2000 electrodes while changing the applied voltage.

FIG. 6 is a schematic configuration diagram of a cultivation nutrient solution treatment device according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... tank (unprocessed liquid), 2 ... electrolytic cell, 21 ... carbon-based electrode, 3 ... electrolytic cell, 31 ... platinum-based compound electrode,
4 ... Pump, 5 ... Tank (processed liquid)

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) C25B 15/02 302 C25B 15/02 302 F term (reference) 2B314 MA30 MA46 PA13 PA20 4D061 DA02 DB01 DB20 EA02 EB04 EB14 EB18 EB29 EB30 EB35 4K011 AA15 AA16 DA01 4K021 AA01 BA02 BB03 BC01 CA06 CA08 DA06 DA09 DA13 DC01 DC13 DC15

Claims (14)

[Claims] 1. A carbon-based or platinum-based compound electrode comprising 0.9 to
A method for treating a cultivating nutrient solution, comprising applying a voltage of 3.0 V and bringing the cultivating nutrient solution into direct contact with the electrode to perform electrode treatment. 2. A voltage of 0.9 to 3.0 V is applied to the plurality of carbon-based electrodes or the plurality of platinum-based compound electrodes, and the cultivation solution is brought into direct contact with the plurality of carbon-based electrodes or the platinum-based compound electrodes. And a multi-electrode treatment. 3. The method according to claim 1, wherein a voltage applied to the carbon-based electrode is lower than a halogen decomposition voltage.
The method for treating the cultivated nutrient solution according to the above. 4. The voltage applied to the carbon-based electrode is 0.9-1.
The method for treating a cultivated nutrient solution according to claim 1 or 2, wherein the method is 8V. 5. A voltage applied to a platinum-based compound electrode is 1.5
The method for treating a cultivated nutrient solution according to any one of claims 1 to 4, wherein the voltage is set to ~ 3.0V. 6. An electrolytic cell provided with a carbon-based electrode to which a voltage of 0.9 to 1.8 V is applied and which performs an electrode treatment by contacting with the cultivation solution that has flowed in, or an electrolytic cell having a voltage of 1.5 to 3.0 V. An apparatus for treating a cultivating nutrient solution, comprising: an electrolytic tank provided with a platinum-based compound electrode that is applied with a voltage and performs an electrode treatment by being brought into contact with the introduced cultivating nutrient solution. 7. An electrolytic cell provided with a plurality of carbon-based electrodes to which a voltage of 0.9 to 1.8 V is applied and which performs a multi-electrode treatment by coming into contact with the inoculated cultivation solution, or 1.5 to 3 A cultivation nutrient solution treatment device, comprising: an electrolytic cell provided with a plurality of platinum-based compound electrodes to which a voltage of 0.0 V is applied and which performs a multi-electrode treatment by coming into contact with the introduced cultivation solution. 8. An apparatus for treating a cultivating nutrient solution having an electrolytic cell provided with a carbon-based electrode, wherein a plurality of net-like carbon-based electrodes are arranged in an overlapping manner along a flowing direction of the cultivating nutrient solution, and the plurality of arrangements are provided. The electrode surface of the carbon-based electrode was disposed so as to be perpendicular to the direction in which the culture solution flows, and a positive or negative voltage is applied alternately to each of the carbon-based electrodes. The cultivation nutrient solution treatment device according to claim 6 or 7, wherein 9. A cultivation method in which a voltage is applied to a carbon-based electrode to perform a first electrode treatment for electrode-treating a cultivation nutrient solution, and a voltage is applied to a platinum-based compound electrode to perform the first electrode treatment. A method for treating a cultivated nutrient solution, comprising performing a second electrode treatment for electrode-treating the nutrient solution. 10. The method according to claim 1, wherein the voltage applied to the carbon-based electrode in the first electrode treatment is lower than the halogen decomposition voltage. 11. The method according to claim 1, wherein the voltage applied to the carbon-based electrode in the first electrode treatment is 0.9 to 1.8 V. 12. The method for treating a cultivated nutrient solution according to claim 1, wherein the voltage applied to the platinum-based compound electrode in the second electrode treatment is 1.5 to 3.0 V. 13. A first electrolytic cell for applying a voltage to a carbon-based electrode for electrode treatment of a cultivation solution, and a cultivation culture applied from a first electrolytic cell for applying a voltage to a platinum-based compound electrode. An apparatus for treating a cultivated nutrient solution, comprising: a second electrolytic tank for electrode-treating the solution. 14. In the first electrolytic cell, a plurality of net-like carbon-based electrodes are arranged in an overlapping manner along a flowing direction of a cultivation liquid, and the electrode surface of the plurality of arranged carbon-based electrodes is cultivated. The cultivation nutrient solution treatment device according to claim 5, wherein the cultivation nutrient solution is arranged so as to be perpendicular to the direction in which the liquid flows, and a positive or negative voltage is alternately applied to each of the carbon-based electrodes.