JP2006158384A - Method for preparation of culture solution for hydroponic culture and method for supplying minor element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problems in the circulating use of a culture solution for hydroponic culture such as water culture comprising the difficulty in the control of pH of the solution, the accumulation of unnecessary nutrients and the contamination of the culture solution with pathogenic microorganisms and enable the circulating use of the culture solution, to provide a method for the preparation of the culture solution for hydroponic culture enabling the control of major elements and minor elements necessary for crops and having different requiring amounts according to the kind and the growing stages of the crop, and to provide a method for supplying the minor elements. <P>SOLUTION: A culture solution for hydroponic culture such as water culture is used as an electrolytic solution and directly electrolyzed by passing a DC current with insoluble electrodes to control the pH of the culture solution for hydroponic culture, supply oxygen to the culture solution, remove the accumulated nutrients and sterilize microorganisms to enable the circulating use as the culture solution for hydroponic culture. A metal or alloy composed of a minor element is used as a soluble electrode and the culture solution is electrolyzed by passing superposed DC and AC current to supply the minor element and keep the element concentration within a controlled range. The root area is heated by controlling the distance between the electrodes and the amount of the current. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention provides a method for adjusting the pH of a culture solution for hydroponics, sterilization and oxygen supply, a method for supplying trace elements, and a method for adjusting a culture solution temperature. Electrolysis by superimposing direct current and alternating current, pH adjustment, temperature adjustment, sterilization and plant growth, oxygen necessary for life cycle, trace amount based on electrode reaction derived from electrode performance It relates to a method of supplying elements.

Many researches have been made on sterilization methods for aqueous solutions, especially sterilization methods by electrochemical means. The electrochemical method includes a method using alternating current electrolysis and a method using direct current electrolysis, and the method using alternating current electrolysis is a method for continuously sterilizing liquids such as drinking water, juice and beer or industrial water. A method of sterilizing by applying a high-voltage AC voltage, for example, supplying treated water into a high electric field where the voltage H (V) applied to the applied electrode wire gap d (mm) is 200 <H / d <2000 An apparatus for sterilization is disclosed (Patent Document 1).

On the other hand, as a wastewater treatment method, a specific high-frequency alternating current is passed between the electrodes, the metal ions of the electrode are eluted, and impurities in the liquid to be treated are subdivided by a high-frequency alternating electric field to separate it from water. Disclosed are wastewater treatment methods and apparatuses that enhance the facilitating property, reduce the oxidation-reduction potential, facilitate a large amount of water treatment, and treat wastewater (Patent Documents 2 and 3).

Also, a wastewater treatment technique using direct current / alternating current and alternating current square wave as an electrolytic treatment method for wastewater is disclosed (Patent Document 4). Furthermore, as a method of effectively performing sterilization, sterilization and sterilization of microorganisms electrochemically, a method of performing an electrochemical treatment by applying alternating current or direct current to water to be treated containing microorganisms is disclosed (patent) Literature 5, 6, 7).

As for the sterilization method by direct current electrolysis, it is already known that electrolysis of chloride ions and dilute hydrochloric acid in fresh water produces hypochlorous acid and sterilization by the oxidizing power of the hypochlorous acid, and many products are sold. ing. In the DC electrolysis technique, a technique is also disclosed in which the polarity of the anode and the cathode is periodically changed because calcium and magnesium are deposited on the cathode. Recently, sterilization with titanium oxide using photocatalytic technology, and practical use of liquid purification technology have been made, and technologies such as purification and sterilization of nutrient solution using photocatalyst and agricultural wastewater treatment with sunlight have been disclosed (for example, non-patented) Reference 1).

Patent No. 2848591 JP 2000-263050 A US6706168B2 Patent No. 2958545 Patent No. 3150355 Patent No. 3180318 Japanese Patent No. 3216015 Facility and Gardening No.119

The present invention is derived from electrode performance by electrolyzing a DC current and an AC current superimposed on an electrode in a culture solution for nutrient solution cultivation in the method for adjusting the nutrient solution culture solution and supplying the trace element. The present invention relates to a method for supplying oxygen and trace elements necessary for pH adjustment, temperature adjustment, sterilization and plant growth, life cycle, and life cycle of a culture solution for hydroponics based on an electrode reaction. Among conventional techniques, as a sterilization method, a method of supplying treated water in a high electric field, applying an alternating current to an installed metal titanium coil, and sterilizing the electrode by discharging the alternating current is a patent document. 1 is disclosed. Here, as disclosed by the inventor, the electrode is "Also, the frequency of sterilization is expected to increase the sterilization effect, but considering the corrosion of the electrode and the stability of the treatment, , 50 kHz or less, preferably 20 kHz or less. Furthermore, “Alternatively, the alternating voltage applied between the pair of electrode wires 3 and 3 may be an alternating current having a frequency higher than a normal commercial high frequency. In other words, this makes it possible to reduce the electrolysis generated on the surfaces of the electrodes 3 and 3, thereby improving the durability of the apparatus and reducing the influence on the treated water. It is disclosed. However, in this patented technology, corrosion and dissolution of the metal titanium coil, which is an electrode generated by the applied alternating current, and the electrode reaction itself occurring on the metal titanium coil are fatal problems, and are used for a long time. Is impossible to do.

Further, the patent technology states that “If the electric conductivity of the liquid to be sterilized is too large, a necessary voltage cannot be applied and the sterilizing effect is reduced. The rate is preferably less than or equal to some extent, ”the high electrical conductivity of the electrolyte preferred for the electrolytic reaction by direct current is described as a problem of the patented technique.

However, introducing treated water into a high electric field for sterilization is very dangerous because it leads to leakage current, electric shock, etc. due to discharge, and has problems such as high power consumption and corrosion of the device. At the same time, since a high voltage is applied to the electrode, a short life due to corrosion of the electrode makes it difficult to operate safely and stably for a long time. Therefore, there is a fundamental and fatal problem that the bactericidal effect by continuous electrolysis cannot be obtained.

Patent Documents 2 and 3 relate to electrodes used in the patented technology as wastewater treatment methods. “The electrodes are plate electrodes and multiple concentric pipe electrodes, and various metals can be selected depending on the water to be treated. For example, applying the properties of metal ions such as titanium, platinum, palladium, iridium, carbon, aluminum, magnesium, zinc, copper, silver, etc. "and further," such multiple concentric pipe electrodes. Is effective particularly for aqueous solutions with low electrical conductivity such as oil, pure, ultrapure, etc., and can efficiently perform electrolysis of aqueous solutions with low water temperature. As the material, preferably, stainless steel, copper, silver, platinum, zinc, aluminum, magnesium, titanium, etc. can be selected. " The frequency is a high frequency that matches the water quality in the frequency band in which metal ions are eluted in AC electrolysis of the liquid to be treated. A method of performing wastewater treatment in which metal ions are eluted by loading and agglomerating and separating impurities such as sludge and organic matter is disclosed. The higher frequency of the AC voltage used in the patent technology is 70 to 310 kHz, and the lower frequency having a self-cleaning action is 10 to 70 Hz. That is, Patent Documents 2 to 3 are methods in which alternating current electrolysis is performed using a metal electrode, and the wastewater treatment is performed by the cohesive force of the dissolved metal ions by dissolving the metal electrode.

The patented technology is a method of supplying metal ions using alternating current electrolysis, but when the metal is dissolved by passing an alternating current through the metal, the current is ionized during the anodic polarization, the metal oxide, Consumed to generate oxygen. On the other hand, during negative polarization, current is consumed for various electrode reactions such as reduction of metal ions and metal hydroxides, generation of hydrogen, and the like. In addition, in AC electrolysis, the anodic reaction and the cathodic reaction occur alternately by the number of times per second, and there is a delay in the electrode reaction with respect to the alternating electric field of the alternating current derived from the ion diffusion rate, etc. Then, it has the fault that it is difficult to adjust the supply amount of a specific metal ion to be constant.

In Patent Document 4, as a method for treating sewage, copper, aluminum, or iron metal is used as an electrode, DC, AC, or AC square wave is applied to the electrode, and sewage is passed between the electrodes for contact oxidation. After that, the solids in the treatment liquid were separated to reduce metal ions, BOD, COD, Escherichia coli, general bacteria, and phosphoric acid, and the electrode was a soluble anode as in Patent Technologies 2-3 and eluted. It is a method of treating sewage by agglomerating and separating by the cohesive force of a large amount of metal ions, and the purpose of this patented technology is to adjust the supply amount of a specific metal ion to a very small amount simultaneously with sterilization. It has the disadvantage of being difficult. In addition, by applying a direct current to the electrode used in the technology, the metal electrode used as the anode is dissolved, and a large amount of metal ions are eluted in the solution, resulting in secondary pollution of the environment. It has the problem of being aroused.

Patent technology disclosed in Patent Documents 5 to 7 is a bipolar three-dimensional electrode electrolysis having a bipolar three-dimensional electrode made of a carbon-based material for electrochemically treating treated water containing microorganisms. Applying DC or AC voltage to the three-dimensional electrode installed in the electrolytic cell in the tank to polarize the three-dimensional electrode, and sterilize the treated water by contacting the treated water with the polarized three-dimensional electrode Is disclosed. In this patented technology, as a three-dimensional electrode, a carbon-based material, a platinum group metal oxide-coated titanium material (dimensionally stable electrode), a platinum-coated titanium material, nickel, ferrite, etc., or a noble metal coating on the carbon-based material What is formed from the applied material is disclosed.

However, nutrients necessary for the growth and life cycle of plants are dissolved in the culture solution for hydroponics. The three-dimensional electrode having an enormous surface has not only an efficient redox reaction, but also has a function of adsorption and filtration, and therefore has a fatal defect that nutrients in the culture medium for nutrient solution cultivation are adsorbed and removed. In particular, a three-dimensional electrode made of a carbon-based material reacts with the nascent oxygen accompanying the generation of oxygen at the time of anode, and the carbon is consumed, so that uniform treatment cannot be performed within a short period of time. The exhaustion occurs even in a material obtained by coating a carbon-based material with a noble metal coating, and when the exhaustion of the carbon material further proceeds, the carbon collapses and may contaminate the treated water. Therefore, these materials cannot be used as electrodes. Due to technical differences from the present invention, the techniques disclosed in Patent Documents 5 to 7 are completely different from the techniques of the present invention.

Further, even with electrodes other than carbon such as nickel and ferrite, consumption and collapse due to dissolution occur as in the case of carbon electrodes. Moreover, the fatal defect that the nutrient in the culture solution for hydroponics is adsorbed, filtered and removed cannot be avoided. In addition, clogging due to adsorbate occurs in the three-dimensional electrode layer, and the liquid does not flow due to precipitation of calcium and magnesium compounds in the treated water, and polarization becomes difficult and cannot be contacted with the treated water. The performance of will decline.

Non-Patent Document 1 discloses a result of a nutrient solution purification / sterilization method using a titanium oxide photocatalyst. In this document, when a culture solution is circulated using an organic medium, there is a concern about plant pathogens for plant growth inhibition and stable production due to organic substances accumulated in the circulation culture solution. The culture medium was purified and sterilized using light. The purification treatment effect of the culture broth was performed by analyzing the TOC (total organic carbon) and measuring the absorbance. As a result, the effect of the titanium oxide photocatalyst became clear and it was shown that the technique is effective even in cloudy weather.

However, since the intensity of ultraviolet rays in sunlight is as low as 1 mW / cm2, it is necessary to increase the area of the device to increase efficiency. Therefore, the development of higher efficiency photocatalysts has been continued. Moreover, the combined use with the apparatus which uses an ultraviolet lamp as an alternative to sunlight, or an ozone generator is examined. The method of using an ultraviolet lamp as a light source has a drawback that the optical path is shortened due to soiling of the nutrient solution or accumulation of organic substances in the nutrient solution, resulting in a decrease in processing capability. In addition, a cleaning device for solving the problem is required, which increases the size of the device and increases costs. Similarly, the combined use of an ozone generator causes an increase in size and cost of the device.

The present invention, when circulating and using nutrient solution culture medium containing trace elements and organic matter necessary for the life cycle of fertilizers and plants, pH adjustment, culture solution temperature, root zone temperature without changing the composition of the culture solution For the purpose of adjusting and sterilizing, and supplying oxygen and trace elements, electrolysis by superimposing direct current and alternating current on the soluble electrode for supplying insoluble electrodes and trace elements in the culture solution, It is an object of the present invention to provide a safe and inexpensive method for solving various problems.

The culture solution for hydroponics is prepared according to the type of plant that grows the fertilizer produced by each fertilizer manufacturer, and diluted with tap water or well water. The fertilizer includes water-soluble nitrates, phosphates, sulfates, organic acid salts, chelate salts, and the like. The concentration control of the prepared culture solution is mainly performed by measuring electric conductivity. The recommended value of electrical conductivity varies depending on the growth stage of the plant, but is in the range of 0.1 to 0.3 S / m. As pointed out in Non-Patent Document 1, the circulating culture solution tends to become a hotbed of pathogenic bacteria due to eutrophication, and once it becomes sick, it spreads throughout the culture solution in a short time.

In addition to the method using electrochemical means, a method in which the culture solution is subjected to heat treatment has been studied, but the apparatus becomes large, the cost is enormous, and it takes a long time to depreciate. Therefore, the electrochemical treatment method is advantageous in terms of equipment, energy cost, etc., unless the composition of the culture solution is changed.

Direct electrolysis of a special aqueous solution such as a culture solution for hydroponics, sterilization without changing the composition, and supplying the trace elements necessary for plants have never been carried out. This is presumably because direct electrolysis of the culture broth may elute electrode components into the culture broth or alter the components in the culture broth due to oxidation-reduction reactions caused by electrolysis.

As a result of diligent research to solve the above problems, direct electrolysis of a special aqueous solution such as a culture solution for hydroponics with an insoluble electrode does not produce deposits on the surface of the anode or cathode, and the pH of the culture solution It has been found that the culture medium can be sterilized without producing hypochlorous acid. In addition, metals that contain the components to be supplied, which are indispensable for the growth of plants, especially those that are passively attached to the metal surface during anodic polarization in a weakly acidic to weakly alkaline aqueous solution with a pH of 4.5 to 8 as in the culture solution. By connecting the metal that forms the oxide film due to oxidization in parallel to the cathode that continues DC electrolysis with an insoluble electrode and superimposing AC current, the metal surface of the trace element to be supplied is positively polarized on the metal surface of slime and smut It can be dissolved without forming an oxide film or the like due to passivation, and the amount of dissolution can be controlled by the amount of energization. By superimposing current and directly electrolyzing the culture solution as an electrolyte, the pH of the culture solution for nourishing culture, the number of pathogenic bacteria, the amount of dissolved trace elements, the amount of oxygen generated, the root zone temperature, the culture solution temperature, the total carbon concentration Adjust As a result, the present invention was found.

Specifically, the insoluble anode, insoluble cathode and insoluble electrode used in the present invention are selected from platinum, iridium, ruthenium and palladium as an electrode catalyst when the electrode base is a metal of titanium, tantalum, niobium, zirconium or an alloy thereof. A composite oxide coating layer comprising an electrode catalyst containing at least one metal or metal oxide and a dispersion of an electrode catalyst selected from metal oxides of titanium, tin, tantalum, antimony, niobium and zirconium An insoluble anode, an insoluble cathode, and an insoluble electrode that are already commercially available can be used, but it is essential that they are insoluble.

Insolubility not only prevents the culture solution from being contaminated with electrode components, but is an indispensable element for controlling the target electrode reaction. Metals such as iron, nickel, stainless steel, copper, and silver cannot be used as the insoluble anode, insoluble cathode, or insoluble electrode of the present invention due to anodic dissolution and carbon or ferrite type electrode collapse due to oxidation or reduction.

As the insoluble anode, insoluble cathode and insoluble electrode, for example, a calcined electrode manufactured by Nippon Carlit Co., Ltd. can be used. Furthermore, a calcined electrode using a platinum group metal oxide with improved corrosion resistance as disclosed in JP-A-2003-293196 and JP-A-2004-204328 can also be used, and the insoluble anode used in the present invention can be used. Suitable as an insoluble cathode and an insoluble electrode.

The insoluble cathode used in the present invention is indispensable to be insoluble in the culture solution like the insoluble anode. As the cathode material, a highly corrosion resistant metal such as titanium, tantalum, niobium, zirconium, or an alloy thereof is suitable. Furthermore, using these metals as electrode substrates, and using an insoluble cathode coated with one or more metals, alloys or metal oxides selected from platinum, iridium, ruthenium and palladium as electrode catalysts on the electrode substrates, cathodic reaction By suppressing the overvoltage of hydrogen generation, it is possible to reduce the electrolysis voltage and reduce the power consumption, which is suitable as the insoluble cathode of the present invention.

The shape of the anode and cathode of the present invention can be any shape depending on the application because the substrate is a metal. In addition, since it is insoluble, there is no change in shape due to dissolution, etc., so the electrode should be adapted to the installation location such as the form of the nourishing culture system used, the source of bacterial contamination, the supply position of trace elements, the ease of management, etc. What is necessary is just to determine a shape. For example, if it is installed in the state of a non-diaphragm in the passage of the culture solution, a mesh electrode or a rod-shaped substrate having an expanded metal electrode substrate that does not interfere with the flow of the culture solution is electrically joined by means such as welding. Comb electrodes are preferred.

In addition, in the case of a hydroponic culture system that performs hydroponic cultivation in which the culture broth is centrally managed, any plate-like, rod-like, or net-like electrode can be used in the centralized control tank. . Furthermore, an electrode in which a mesh electrode is electrically joined to a rod-like electrode by means such as welding, and similarly, an electrode in which a plurality of mesh electrodes are joined is suitable. If it is the electrode of this shape, it can also be used as a strainer other than the objective of this invention.

The electrode can be installed at any place. After adjusting the fertilizer, it may be installed as a pH adjusting device, an oxygen supply facility, or a trace element supply device. In particular, in the case of installation for sterilization, the inside of the culture solution passage which is in contact with the atmosphere and easily contaminated with bacteria is preferable. Moreover, these may be provided side by side, and a plurality of electrodes may be installed in a distributed manner. In particular, in order to carry out root area warming cultivation, the electrodes are installed in the root area of the organism to be cultivated, and the root area is generated by heat generated by electrolysis. , And the electrical conductivity and pH, concentration of trace elements, root zone temperature, culture solution temperature, luminescence from microorganism-derived adenosine phosphate (ATP, etc.) or nutrient solution at each electrode installation location. It is desirable to measure and control the number of bacteria and adjust the fertilizer concentration, electrode installation position, distance between electrodes, and the amount of energization current.

The soluble electrode used in the present invention comprises one or more selected from titanium, silicon, aluminum, iron, manganese, zinc, copper, molybdenum, nickel, phosphorus, calcium, magnesium, boron, sulfur, nitrogen, and carbon. It is a metal or an alloy. For example, high-silicon cast iron, which is an alloy of iron and silicon, phosphorous copper, aluminum magnesium zinc, ferromanganese, ferromolybdenum, ferrotitanium, ferroboron, silicomanganese, ferroaluminum, carbon ferromanganese, ferrozinc nickel, zinc nickel, calcium Molybdenum, ferromolybdenum tungsten, ferrophosphos, ferroniobium, carbon ferromolybdenum, silicomanganese ferrochrome, ferrozircon, magnesium zinc zirconium calcium, calcium silicon titanium, titanium copper nickel, titanium boron, titanium molybdenum, etc. can be used. It is preferable to control the amount of energization by analyzing the amount of dissolution by electrolyzing the solution as an electrolyte.

Furthermore, the culture medium for hydroponics contains nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, carbon, oxygen, hydrogen, iron, manganese, boron, copper, zinc, molybdenum, chlorine, sodium, silicon, aluminum, It consists of nickel, phosphate, sulfate, ammonium salt, organic acid salt, chelate salt, organic fertilizer component aqueous solution, and is a circulating culture solution for hydroponics.

In general, when water electrolysis is performed on a non-transparent membrane through a direct current using an insoluble electrode, water is electrolyzed and oxygen is generated at the anode as an electrolytic oxidation reaction, and hydrogen is generated as an electrolytic reduction reaction at the cathode. As a result, water is decomposed and reduced to oxygen and hydrogen, but the pH of the electrolyte does not change. On the other hand, when an aqueous solution containing chlorine ions is electrolyzed, the pH rises and an alkaline hypochlorous acid aqueous solution is obtained.

However, the electrolysis of the culture solution for nutrient solution cultivation using an insoluble anode and an insoluble cathode as an electrolyte solution causes the pH of the culture solution for nutrient solution cultivation to change to the acidic side and to originate from a microbial reaction. The amount of luminescence based on adenosine phosphate (ATP, etc.) decreases, that is, the pH can be adjusted by electrolysis, the bactericidal effect is obtained, the dissolved oxygen concentration in the culture solution increases, and the electrode It is possible to increase the temperature of the culture solution by controlling the distance between them, the current value and the electrical conductivity of the culture solution, so that electrolysis is effective for plant cultivation, that is, insoluble anode and insoluble cathode The present invention is capable of adjusting the culture solution for nutrient solution cultivation by direct current electrolysis using the culture solution for nutrient solution cultivation as an electrolyte solution.

On the other hand, when AC electrolysis is performed using the insoluble anode, the insoluble cathode and the insoluble electrode of the present invention, these electrodes are derived from having a capacitor capacity as an electrode performance, and current is applied at the time of polarization corresponding to the AC frequency. Since the polarity changes before charging and the discharge current contributing to the electrode reaction, the electrolytic reaction does not proceed apparently. This is because these insoluble electrodes have an insoluble metal oxide coating layer as an electrode catalyst.

On the other hand, when a metal is used as an electrode for alternating current electrolysis, the metal does not have an electric capacity, so the electrode reaction corresponding to alternating current, particularly when the electrolyte concentration is low such as a culture solution, the metal Electrode reactions such as ion dissolution, passivation, oxygen generation, hydrogen generation, metal hydroxide generation and reduction reactions are performed.

Therefore, when AC electrolysis is performed using an insoluble electrode and a metal electrode of a trace element supplied to the culture medium or an alloy as the electrolyte, the metal other than valve metals such as silicon, titanium, and tantalum when positively polarized The metal constituting the electrode dissolves as ions. However, in the case of a valve metal, it is considered that a stable oxide film is formed on the metal surface and is rendered passivated or insoluble by generating oxygen. For example, when high-silicon cast iron, which is an alloy of silicon and iron, is used as a soluble electrode, silicon is passivated and insoluble, but iron ionizes and dissolves, so iron ions are supplied as a trace element in the culture solution. It becomes possible. Similarly, when an alloy of titanium and aluminum is used, titanium is passivated and aluminum is dissolved as ions.

Furthermore, when a direct current is superimposed on the alternating current electrolysis, the electrode potential of the soluble electrode is lowered by passing a soluble electrode containing a metal that is easily passivated, such as manganese or molybdenum, as the cathode of the direct current electrode. Since the dissolution potential and the metal are maintained in a stable potential range without being activated, the metal can be dissolved and supplied without being deactivated. The supply amount can also be adjusted by adjusting the amount of alternating current or by adjusting a variable resistor in an electric circuit formed as an electrolyzer. In addition, the type and supply amount of the supply trace element can also be obtained by electrically joining a plurality of kinds of soluble metal electrodes consisting of trace elements supplied to the culture medium for hydroponics between the insoluble electrodes so as to be bipolar. It is also possible to adjust. Moreover, there is no particular limitation on the frequency of the alternating current to be energized. The use of a commonly used frequency can be inexpensive because it does not require expensive equipment such as a frequency converter. It is desirable to measure the electrode potential and set the operating conditions, but in practice, since pH adjustment, sterilization, oxygen supply, etc. are performed at the anode of direct current electrolysis, it dissolves depending on the type of soluble electrode, metal composition, etc. Since the amount varies, it is desirable to create a calibration curve regarding the amount of direct current applied, the amount of alternating current applied, and the amount of dissolved metal ions for each type of soluble electrode. By this operation, even in the alternating current electrolysis using alternating current, stable electrolysis can be continued even if the direct current is superimposed on the alternating current, and the trace element can be stably supplied.

That is, by the electrolytic technique of the present invention, the pH control of the culture solution for hydroponics, the sterilization of the culture solution, the enrichment of dissolved oxygen in the culture solution, the adjustment of the culture solution temperature and the root zone temperature of the root zone warming cultivation It is possible to adjust the culture medium such as control and supply and concentration control of trace elements.

The present invention provides a method for preparing a culture solution for nutrient solution cultivation and a method for supplying a trace element, wherein the insoluble electrode of the present invention is used in the culture solution for nutrient solution cultivation without adding acid, alkali or pesticide to the culture solution, In addition, by applying direct current and alternating current to the soluble electrode containing trace elements and electrolysis, the pH of the culture solution is adjusted to an appropriate pH at each stage of plant growth, and oxygen is added to the culture solution. By supplying and preventing the generation of “anaerobic denitrifying bacteria” due to lack of oxygen, the consumption decomposition of “nitrogen fertilizer” is suppressed, and furthermore, by sterilizing the culture solution, the pH fluctuates due to root decay and fermentation This makes it possible to grow a nutrient solution cultivated plant in a healthy and uniform quality. In addition, since it is possible to supply trace elements necessary for plant growth and life cycle to the culture solution, the culture solution can be adjusted easily, safely and inexpensively. It has been proved that it is extremely effective from the viewpoint of environmental conservation, fertilizer saving, and prevention of environmental pollution due to reduction of wastewater.

Embodiments of the present invention will be described below. The present invention is not limited to the following examples.

In order to examine whether it is possible to control the pH of the culture medium for hydroponic cultivation of tomatoes and the concentration of zinc, which is a trace element, 10 tons of tomato culture solution was used as the electrolyte. Platinum-plated titanium electrode PLATINODE-101B made by Ishifuku Metal Industry Co., Ltd., in which platinum is plated on a titanium plate with a width of 300 mm, a length of 1000 mm, and a thickness of 2 mm as an insoluble anode of the invention. Exelode C manufactured by Nippon Carlit Co., Ltd., which is a calcined electrode in which expanded metal (aperture: LW6mm, SW3.5mm) is coated with a composite oxide using ruthenium oxide as an electrode catalyst by pyrolysis, is used. A 20 A direct current was passed through the anode and insoluble cathode. On the other hand, Exelod C manufactured by Nippon Carlit Co., Ltd. with an electrolytic area of 50 mm in length and width was used as the insoluble electrode, and a metal zinc plate was used as the soluble electrode. Anode zinc metal plate as a counter, Exerciser load C by energizing a direct current of 15mA as a cathode was investigated the time course of pH and concentration of zinc while growing tomatoes. As for tomato culture solution, fertilizer was not added to 10 tons, and the results of investigating changes in pH and zinc concentration in the present invention when electrolysis was not introduced and when the electrolysis was performed were shown in FIG. As shown in FIG.

From the results of FIG. 1 and FIG. 2, the pH of the culture solution of the comparative example in which electrolysis was not performed reached pH 6.6, which was outside the control range, but when the culture solution was directly electrolyzed with the insoluble electrode of the present invention. The pH of the culture solution could be in the range of pH 5.5 to pH 6.5 suitable for tomato growth.

On the other hand, the zinc concentration, which is a trace element, decreased to 0.29 ppm in the culture solution of the comparative example in which electrolysis was not performed, and was below the control range, but in the method of the present invention, 0.66 ppm to 0.47 ppm. It became clear that it could be maintained within the zinc concentration control range.

When manganese was electrolyzed as an anode, an oxide was generated on the electrode surface and it was difficult to dissolve, so manganese was supplied by an alternating current. The insoluble anode and insoluble cathode of the present invention are made of titanium expanded metal as an electrode substrate, and an electrode catalyst having an electrolysis area of 300 mm wide, 1000 mm long, and 1 mm thick is formed of 60% iridium oxide and 40% tantalum oxide. After immersing the hydrochloric acid solution of iridium chloride and tantalum chloride prepared in hot oxalic acid, apply it to titanium expanded metal (mesh opening: LW4.5mm, SW3mm) and heat-decompose at 550 ℃ Repeatedly, an insoluble anode and an insoluble cathode were produced. A direct current of 20 A was applied to the pair of insoluble anode and insoluble cathode. On the other hand, using the same electrode as the insoluble electrode energized with direct current, using metal electrolytic manganese as the soluble electrode, energizing 100 mA alternating current to a pair of electrodes with a size of 100 mm in length and width, while growing tomato The changes with time of pH and manganese concentration were investigated. Tomato broth was not added fertilizer to 10 tons, pH change and change in manganese concentration of tomato broth introduced with the comparative example in which the diaphragm electrolysis of the present invention was not introduced and the electrolysis method of the present invention. The survey results are shown in FIGS.

From the results shown in FIG. 3, in the comparative example in which the electrolysis was not performed, the pH was 6.5 or more, exceeding the control range value, and the manganese concentration was reduced to 0.12 ppm, which was below the control range value. On the other hand, the pH and manganese concentration of the tomato culture solution into which the electrolysis method of the present invention has been introduced are within the control range, and direct current electrolysis by the insoluble electrode of the present invention and a metal composed of a trace element as a soluble electrode, an alternating current is supplied to the insoluble electrode. It was found that by performing AC electrolysis to energize in a culture solution, it is possible to prepare a culture solution for nutrient culture and supply a manganese component as a trace element.

Furthermore, in order to easily supply manganese ions into the culture solution, when electrolysis was performed in the same manner as in Example 2, a 20 A DC current was passed through a pair of insoluble anode and insoluble cathode, while a DC current was passed through the insoluble electrode. The same electrode is used as a soluble electrode, and a metal electrolytic manganese plate is used as a soluble electrode. A pair of electrodes with a size of 100 mm in length and width is used as an anode, an insoluble electrode is used as a cathode, and a DC current of 10 mA is applied as a metal electrolytic manganese plate as a cathode. Furthermore, tomatoes were cultivated with 100 mA alternating current superimposed, and changes over time in pH and manganese concentration were investigated. The results are shown in FIG.

From the results shown in FIG. 5, the nutrient solution is obtained by performing direct current electrolysis using the insoluble electrode of the present invention and superposition electrolysis in which a direct current and an alternating current are superimposed and applied to the insoluble electrode in the culture solution. It was proved that the culture medium for cultivation and the supply of manganese components as trace elements were possible.

When molybdenum was electrolyzed as an anode in the control pH range of the culture solution, an oxide was formed on the electrode surface and it was difficult to dissolve, so dissolution and supply as molybdate ions were carried out with a superimposed current of direct current and alternating current. As an insoluble anode and an insoluble cathode of the present invention, an electrode substrate is an expanded metal made of titanium (aperture: LW 6 mm, SW 3.5 mm), an electrolytic area is 300 mm wide, 1000 mm long, and 1 mm thick. Load B was used as an insoluble anode, and Excel load C was used as an insoluble cathode, and a direct current of 20 A was applied to the pair of insoluble anode and insoluble cathode. On the other hand, using the same size titanium (70 atomic%)-molybdenum (30 atomic%) alloy as the soluble electrode and Excelo C having a size of 50 mm in length and breadth, Excel C is the cathode for the pair of electrodes. A tomato was cultivated while applying a direct current of 5 mA and further applying a 30 mA alternating current, and changes in pH and molybdenum concentration over time of the culture medium for tomato culture medium cultivation were investigated. Tomato broth was cultivated without adding fertilizer to 10 tons, investigating changes in pH and molybdenum concentration of the tomato broth introduced with the comparative example without electrolysis and the electrolysis method of the present invention. The results are shown in FIGS.

From the results shown in FIGS. 6 and 7, in the comparative example in which the electrolysis was not performed, the pH was 6.5 or more, exceeding the control range value, and the molybdenum concentration was lowered to 0.04 ppm and was below the control range value. On the other hand, the pH and the molybdenum concentration of the tomato culture solution into which the electrolysis method of the present invention has been introduced are within the control range, and the direct current electrolysis with the insoluble electrode of the present invention and the metal consisting of trace elements as the soluble electrode, the direct current is applied to the insoluble electrode. It has been found that by performing electrolysis in which the alternating current is superimposed and applied in the culture solution, it is possible to adjust the culture solution for nutrient solution cultivation and supply the molybdenum component as a trace element.

Using a titanium (30 atomic%)-copper (70 atomic%) alloy as a soluble electrode, with the soluble electrode as an anode, a direct current of 5 mA was passed through a pair of electrodes with a size of 50 mm in length and width, and an alternating current of 25 mA In the same manner as in Example 4 except that superposed energization was carried out, changes in luminescence based on pH, copper concentration, and adenosine phosphate (ATP, etc.) derived from microbial reaction were investigated while tomato cultivation was conducted. Tomato broth was not added fertilizer to 10 tons, pH change, copper concentration and luminescence amount of the tomato broth introduced the comparative example without introducing the diaphragm electrolysis of the present invention and the electrolysis method of the present invention The results of investigating these changes are shown in FIG. 8, FIG. 9, and FIG.

From the results of FIG. 8 and FIG. 9, in the comparative example in which the electrolysis was not performed, the copper concentration became 0.024 ppm below the lower limit value of the control range after 12 hours, but in the method of the present invention, it was maintained within the control range. did it. On the other hand, as shown in FIG. 10, the amount of luminescence of the tomato culture solution into which the electrolysis method of the present invention was introduced decreased to about 31% of the initial value after 120 hours, but in the comparative example, it showed a slightly increasing tendency from the initial value. According to the method of the present invention, the pH and copper concentration of the tomato culture solution can be maintained within the control range, and the amount of luminescence by ATP derived from the microbial reaction is reduced, so that the bactericidal effect by electrolysis was confirmed. That is, by performing direct current electrolysis using the insoluble electrode of the present invention and a metal composed of a trace amount element as a soluble electrode, and performing electrolysis in which direct current and alternating current are superimposed on the insoluble electrode in the culture liquid, It was found that adjustment and supply of copper components as trace elements were possible and also had a bactericidal effect.

Hydrochloric acid solution of iridium chloride and tantalum chloride prepared so as to be 60% iridium oxide and 40% tantalum oxide which are the same electrode catalyst as in Example 2 on a round bar made of titanium having a diameter of 20 mm and a length of 500 mm Was applied to a titanium round bar after pickling and repeated thermal decomposition at 550 ° C. to produce an insoluble anode. Using the same shape of metal zirconium as an insoluble cathode, immersing the insoluble anode and the insoluble cathode in the NFT hydroponic culture medium return tank of a 50-m tomato cultivation tank, energizing a 30 A direct current, and continuous diaphragm electrolysis Went. On the other hand, a 3 mm thick iron-boron alloy was used as a soluble electrode, and a 3 mm thick metal zirconium platinum plated 3 μm thick electrode was used as an insoluble electrode. The electrolytic treatment was carried out by applying a direct current of 0.2 A so that the iron-boron alloy soluble electrode became an anode, and further superposing an alternating current of 1.5 A. Using the electrolyzed water as raw water, after preparing and supplying fertilizer, measure the dissolved oxygen concentration and boron concentration in the culture solution at the outlet of the channel, and in the culture solution required for culture by the culture solution adjustment method of the present invention Whether dissolved oxygen and boron, which is a trace element, are ensured in the control concentration range was compared with the case where electrolysis was not performed. The results of the comparative example are shown in FIG. 11, and the electrolysis results of the present invention are shown in FIG.

From the results of FIG. 11, it can be seen that when electrolysis is not performed, the pH, dissolved oxygen, and boron concentrations in the culture solution fluctuate with time and fall outside the control concentration range. On the other hand, from the results of the example of the present invention of FIG. 12, it was found that the pH, dissolved oxygen, and boron concentration of the culture solution can be maintained within the control concentration range by introducing the electrolysis method of the present invention. did. Thus, by introducing the electrolysis method of the present invention, stable high-quality products and a high production amount can be expected while maintaining target production conditions.

Japan is a calcined electrode in which a titanium expanded metal (mesh opening: LW6mm, SW3mm) having an electrolytic area of 100mm in length, 100mm in width and 1mm in thickness is coated with a composite oxide using ruthenium oxide as an electrode catalyst by pyrolysis. Exceed C made by Carlit Co., Ltd. is used as an insoluble anode, Exeroad R-1000 using platinum as an electrocatalyst for titanium expanded metal of the same shape as an insoluble cathode, and a phosphorus-containing copper plate that is an alloy of copper and phosphorus as a soluble electrode The insoluble anode and soluble electrode are of the same polarity, the cathode side is a common insoluble cathode, 20A direct current is passed between the insoluble anode and insoluble cathode, and 20-30mA alternating current is passed between the soluble electrode and insoluble cathode. Then, a resistor is connected between the DC circuit and the AC circuit to form a circuit capable of supplying the desired current, and the tomato The cultivation was carried out. During this period, the pH, copper concentration, and the culture solution were collected, and after culturing at 35 ° C. for 48 hours using a Petrifilm medium for general bacterial count measurement manufactured by 3M Healthcare, the colony count was measured. Indicated.

From the results of FIG. 13, the pH was maintained at approximately pH 6, and the copper concentration was maintained at 0.04 ppm to 0.05 ppm. In addition, the number of general bacteria was sterilized by about 99% after 3 months compared to the initial amount. According to the method of the present invention, the culture solution can be adjusted and managed over a long period of time, and a bactericidal effect can be obtained.

A calcined electrode in which a titanium expanded metal (mesh opening: LW6mm, SW3mm) having an electrolytic area of 100mm in length, 100mm in width, and 1mm in thickness is coated with a composite oxide using ruthenium oxide as an electrode catalyst by thermal decomposition in the atmosphere. Exelode C manufactured by Nippon Carlit Co., Ltd. was used as an insoluble anode, Exelod R-1000 using platinum as an electrocatalyst for titanium expanded metal having the same shape as an insoluble cathode, and a direct current of 20 A was applied. On the other hand, a plate-shaped stone Fukukogyo Co., Ltd. MODE-200 fired electrode having an electrolytic area of 100 mm in length and width of 3 mm is used as an insoluble anode and an insoluble cathode. Using a phosphor-containing copper plate that is an alloy, the soluble electrode is sandwiched between 2 mm thick Viton insulation packing so that the distance between the electrodes is 2 mm, and an AC current of 20 to 30 mA is applied, and both DC electrolysis and AC electrolysis are used. Then, hydroponics of roses with the culture solution was performed while performing continuous electrolysis for about 3 months. During this period, the culture broth was collected, and the pH, total organic carbon concentration, and the general bacterial count and copper concentration were counted after colonization at 35 ° C for 48 hours using a Petrifilm medium for general bacterial count measurement manufactured by 3M Healthcare. The results of measuring are shown in FIG.

From the results shown in FIG. 14, the pH was maintained at approximately pH 6, the total organic carbon concentration was maintained at 100 ppm or less, and the copper concentration was maintained at approximately 0.06 ppm. In addition, the number of general bacteria was sterilized by about 99% after 3 months compared to the initial amount. According to the method of the present invention, the culture solution can be adjusted and managed over a long period of time, and a bactericidal effect can be obtained.

In the same manner as in Example 8, in a rose culture solution, 1 μm of platinum was used as an insoluble anode for adjusting the culture solution to a titanium expanded metal (mesh opening: LW8 mm, SW4 mm) having a size of 500 mm in length and width and 1 mm in thickness. Platinum-plated electrode with electroplating in thickness, electrocatalyst layer in which platinum is supported on porous carbon fiber, which is an electrode material for polymer electrolyte fuel cells having the same shape as insoluble anode as insoluble cathode, and diffusion of oxygen gas A gas diffusion electrode having a layer is used as an insoluble cathode, and a PSA oxygen concentrator SO-004B type manufactured by Sanyo Denshi Co., Ltd. is used as an oxygen supply device. A 20 A direct current is applied to the gas diffusion cathode which is the insoluble anode and the insoluble cathode. Then, the culture solution for hydroponics was electrolyzed as an electrolytic solution. On the other hand, as an insoluble electrode for supplying trace components, Exelod C manufactured by Nippon Carlit Co., Ltd. with an electrolysis area of 100 mm in length and width is an insoluble anode, Exelod R-1000 using platinum as an electrocatalyst on an expanded metal of the same shape and an insoluble cathode A plate-like iron-boron alloy and iron-silicon alloy are used as a soluble electrode between the insoluble anode and the insoluble cathode using an insulating packing as a soluble electrode. An alternating current was superimposed and the culture solution was passed through to electrolyze the culture solution as an electrolyte. Furthermore, sandwiching a metal zinc plate of the same shape as a 3 mm thick plate-like metal electrolytic manganese between the same insoluble anode and insoluble cathode, superposing 0.1 A DC current and AC current, passing the culture solution, and culturing The liquid was electrolyzed as an electrolytic solution. Similarly, a metal molybdenum plate having the same shape as a phosphorus-containing copper plate made of an alloy of copper and phosphorus having a thickness of 3 mm was sandwiched between the insoluble anode and the insoluble cathode, and a 50 mA direct current and an alternating current were superimposed to conduct electricity. These electrolyzers were used for hydroponics of roses that did not generate hydrogen gas from an insoluble cathode while performing direct electrolysis of the continuous diaphragm for about 3 months using the culture solution as the electrolyte. During this period, the culture solution was collected and cultured at 35 ° C. for 48 hours using pH, boron, iron, manganese, zinc, copper, molybdenum and total carbon concentrations and a Petrifilm medium for general bacterial count measurement manufactured by 3M Healthcare. The results of measuring the number of general bacteria in which the number of colonies was counted are shown in FIG.

From the results of FIG. 15, the pH ranges from pH 5 to pH 6, the boron concentration is 0.2 ppm to 0.3 ppm, the iron concentration is 1.2 ppm to 1.5 ppm, the manganese concentration is 0.17 ppm to 0.2 ppm, the zinc concentration is 0.2 ppm, and the copper concentration Was maintained at 0.06 ppm and the molybdenum concentration at 0.05 ppm. In addition, the total carbon concentration was reduced to 12ppm, 97.5% lower than the initial amount. Furthermore, the general bacterial count was approximately 99.5% sterilized after 3 months compared to the initial amount. According to the method of the present invention, the culture solution can be adjusted and managed for a long period of time, a bactericidal effect can be obtained, a trace amount component can be supplied, and the concentration can be maintained at a target concentration.

The cultivation method of grape "Delaware" by NFT, using 3 year-old grafted seedlings, the culture solution concentration of hydroponic cultivation was EC0.5dS / m, and the ratio of nitrate nitrogen to ammonia nitrogen was 2: 1. The total nitrogen concentration was maintained at 20 ppm (about 1.4 me / L). The same shape as the platinum-plated titanium electrode PLATINODE-101B manufactured by Ishifuku Metal Industry Co., Ltd., in which platinum is coated on the surface of a titanium round wire having a diameter of 3 mm and a length of 5000 mm at the bottom of the cultivation bed. A 5A direct current was applied with 5mm between the insoluble anode and the insoluble cathode as an insoluble cathode, and the root area was heated at a root area of 26 ° C by controlling the current value. At the same time, the pH was maintained in the range of pH 6 to pH 7. On the other hand, Exelode C manufactured by Nippon Carlit Co., Ltd., which uses titanium expanded metal with an electrolytic area of 100 mm in length and width as an electrode substrate as an insoluble electrode for supplying trace components, is used as an insoluble anode, and platinum is used as an electrode catalyst for titanium expanded metal of the same shape. Excel load R-1000 is used as an insoluble cathode, and a metal zinc plate of the same shape as a 3 mm thick metal electrolytic manganese plate is sandwiched between the insoluble anode and the insoluble cathode as a soluble electrode with an insulating packing, and a direct current of 0.1 A It was energized with an alternating current superimposed. Similarly, a metal molybdenum plate of the same shape as a 3mm-thick copper-phosphorus alloy plate is sandwiched between the insoluble anode and the insoluble cathode as a soluble electrode, and a 50mA DC current and an AC current are superimposed on each other. did. Using these electrolyzers, and also using multiple HIP-200 solar cells manufactured by Sanyo Electric Co., Ltd. as the power source for the electrolyzers, the energizing current value was adjusted to maintain the root region temperature at 26 ° C. While the culture solution was used as the electrolyte solution, continuous electrolysis was performed directly on the diaphragm, and the root region of the grape "Delaware" was heated. During this time, the culture solution of the present invention was collected, and the number of colonies after culturing at 35 ° C. for 48 hours was measured using pH, manganese, zinc, copper, molybdenum concentration and Petrifilm medium for general bacterial count measurement manufactured by 3M Healthcare Co., Ltd. The result of measuring the number of general bacteria and the result of measuring the temperature in the root zone region are shown in FIG. Table 1 shows the results of comparing the quality of the grown fruits with respect to the fruits that were subjected to the hydroponics management and root region warming cultivation of the present invention and the fruits that were not.

From the results of FIG. 16, the pH is in the range of pH 6.6 to pH 6.8, the manganese concentration is 0.1 ppm to 0.2 ppm, the zinc concentration is 0.3 ppm to 0.4 ppm, the copper concentration is 0.06 ppm to 0.07 ppm, and the molybdenum concentration is 0.04. Maintained between ppm and 0.05 ppm. Moreover, the temperature of the root region was maintained at 26 ° C to 28 ° C. Furthermore, the general bacterial count was about 98.8% sterilized compared to the initial amount. According to the method of the present invention, it is possible to adjust and manage the culture solution over a long period of time, to obtain a bactericidal effect, to supply a trace component, and to maintain the trace component concentration at a target concentration. It was.

表1の結果より、収量で約2.6倍及び房重で約2倍の増収が得られ、糖度でも本発明の方法によって生育した果実の品質が本発明を実施しない比較例と比較して優れていることが明らかである。

From the results of Table 1, the yield was increased by about 2.6 times and the tuft weight by about 2 times, and the quality of the fruit grown by the method of the present invention was superior in sugar content as compared with the comparative example in which the present invention was not carried out It is clear that

Drawing showing pH and Zn concentration change over time of tomato broth Drawing showing pH and Zn concentration change with time of tomato culture solution of the present invention Drawing showing pH and Mn concentration change over time of tomato culture solution Drawing showing pH and Mn concentration change with time of tomato culture solution of the present invention Drawing showing pH and Mn concentration change with time of tomato culture solution of the present invention Drawing showing pH and Mo concentration change over time of tomato broth Drawing showing pH and Mo concentration change with time of tomato culture solution of the present invention Drawing showing pH and Cu concentration change over time of tomato culture solution Drawing showing pH and Cu concentration change with time of tomato culture solution of the present invention Drawing showing ATP luminescence change over time with and without electrolysis in tomato culture solution Drawing showing pH, B concentration and dissolved oxygen concentration change over time of tomato broth Drawing showing pH, B concentration and dissolved oxygen concentration change over time of tomato culture solution of the present invention Drawing showing pH, Cu concentration and general bacterial count change over time of tomato culture solution of the present invention Drawing showing pH, total organic carbon concentration, Cu concentration and general bacterial count change with time of rose culture solution of the present invention Drawing showing pH, trace element concentration, total organic carbon concentration and general bacterial count change with time of rose culture solution of the present invention Drawing showing pH, root zone temperature, trace element concentration, and general bacterial count change over time in the root solution warming cultivation of Udo "Delaware" of the present invention

Claims (14)

Electrolysis using one or more soluble electrodes containing at least a pair of insoluble electrodes and a trace element of the nutrient solution culture medium in the preparation of the nutrient solution culture medium and the trace element supply method In the electrolysis treatment apparatus electrically connected to carry out the above, the culture solution for nutrient solution cultivation is used as an electrolytic solution, an electric current is passed through the electrical circuit, and the adjustment of the culture solution for nutrient solution cultivation and the soluble electrode are performed by electrolysis. A method for preparing a culture solution for hydroponics and a method for supplying a trace element, wherein the trace element is supplied by being corroded and dissolved. Electrolysis using one or more soluble electrodes containing at least a pair of insoluble electrodes and a trace element of the nutrient solution culture medium in the preparation of the nutrient solution culture medium and the trace element supply method In the electrolysis treatment apparatus electrically connected to carry out the above, the culture solution for nutrient solution cultivation is used as the electrolytic solution, the direct current and the alternating current are passed through the electric circuit, and the culture solution for nutrient solution cultivation is adjusted by electrolysis And a method for adjusting the culture medium for nutrient solution cultivation and a method for supplying the trace element, wherein the trace element is supplied by corroding and dissolving the soluble electrode. In the method for preparing the culture medium for nutrient solution cultivation and the method for supplying the trace element, at least one pair of insoluble electrodes and one or more soluble electrodes containing a trace element metal or alloy required for the culture medium for nutrient solution culture are used. In the electrolysis treatment apparatus electrically connected to carry out electrolysis, the culture solution for nutrient solution cultivation is used as an electrolytic solution, and a direct current and an alternating current are superimposed on the electric circuit, and the nutrient solution is obtained by electrolysis. A method for preparing a culture medium for cultivation and a method for supplying a culture element for nutrient cultivation and a method for supplying the trace element, characterized in that the trace element is supplied by corroding and dissolving a soluble electrode. In the adjustment of the culture medium for hydroponics and the method of supplying trace elements, the insoluble anode is electrically connected to the anode of the direct current and the soluble electrode is used as the cathode, and the insoluble anode and the soluble electrode are connected to the direct current and the alternating current. A hydroponic culture broth characterized in that it is energized by superimposing current and electrolyzing the hydroponic culture broth as an electrolyte to adjust the nutrient broth culture broth and supply trace elements. Adjustment method and trace element supply method. In the preparation of nutrient solution culture medium and the method of supplying trace elements, one or more and one or more soluble electrodes are sandwiched between at least a pair of insoluble anodes and insoluble cathodes, and direct current and alternating current between the insoluble anodes and insoluble cathodes. A hydroponic culture broth characterized in that it is energized by superimposing current and electrolyzing the hydroponic culture broth as an electrolyte to adjust the nutrient broth culture broth and supply trace elements. Adjustment method and trace element supply method. In a method for preparing a culture medium for nutrient solution cultivation and supplying a trace element, a nutrient comprising at least a pair of an insoluble anode and an insoluble cathode for supplying a direct current and at least a pair of an insoluble electrode and a soluble electrode for supplying an alternating current In the method for electrolytic treatment of culture medium for liquid culture, direct current and alternating current are applied to each, and the culture liquid for nutrient culture is electrolyzed as an electrolytic solution to adjust the culture medium for nutrient culture and supply of trace elements A method for adjusting a culture solution for hydroponics and a method for supplying a trace element, characterized in that: In the method for preparing a culture solution for hydroponics and supplying a trace element, at least a pair of an insoluble anode and an insoluble cathode for supplying a direct current and at least a pair of an insoluble electrode for supplying an alternating current and the insoluble electrode are fed. In the electrolytic treatment method of the culture solution for nutrient solution cultivation in which one or more and one or more soluble electrodes are arranged between the electrodes and electrically connected to each other, the nutrient solution cultivation is performed by supplying direct current and alternating current to each of them. A method for adjusting a culture solution for nutrient solution cultivation and a method for supplying a trace element, characterized in that the culture solution for electrolysis is electrolyzed as an electrolytic solution to adjust the culture solution for nutrient solution cultivation and supply of the trace element. A trace element to be supplied in the method for preparing a nutrient solution culture medium and supplying a trace element according to claim 1, claim 2, claim 3, claim 4, claim 5, claim 6 and claim 7. Claim 1, claim 2, claim 4, claim 5, claim 6, and claim 6, characterized in that it is a method of supplying a trace element comprising a variable resistor for adjusting the amount of dissolution of 8. A method for adjusting a culture medium for hydroponics and a method for supplying trace elements, characterized in that the culture medium for hydroponics and the supply of trace elements according to claim 7 are performed. In the adjustment method of the culture solution for nutrient cultivation and the supply method of the trace element according to claim 1, claim 2, claim 3, claim 4, claim 5, claim 6, claim 7 and claim 8, Electrolyze the culture medium for hydroponic culture as an electrolyte, adjust the culture medium for hydroponic culture and supply trace elements simultaneously or separately, and the pH, number of pathogens, and dissolved trace element concentration of the culture medium for hydroponic culture Measure the dissolved oxygen concentration, root zone temperature, culture solution temperature, total carbon concentration, and adjust the amount of current flow, distance between electrodes, culture solution resistivity, pH of culture solution for hydroponics, number of pathogenic bacteria, trace amount The amount of dissolved element, the amount of oxygen generated, the root zone temperature, the culture solution temperature, and the total carbon concentration are adjusted, claim 1, claim 2, claim 3, claim 4, claim 5 and claim 6. Hydroponics, characterized in that the nutrient solution culture medium of claim 7 and claim 8 is adjusted and trace elements are supplied. The method of supplying the adjusting method and trace elements in culture medium. The insoluble anode and insoluble electrode electrode base for supplying an alternating current to the insoluble anode are one or more selected from platinum, iridium, ruthenium, and palladium as an electrode catalyst for titanium, tantalum, niobium, zirconium metals or alloys thereof. An insoluble anode having a composite oxide coating layer containing an electrode catalyst containing a metal or metal oxide and a dispersion of an electrode catalyst selected from metal oxides of titanium, tin, tantalum, antimony, niobium and zirconium, insoluble Claim 1, claim 2, claim 3, claim 4, claim 5, claim 7, claim 8, and claim 9, characterized in that a cathode and an insoluble electrode are used. A method for preparing a culture solution for hydroponics and a method for supplying trace elements. The insoluble cathode for passing a direct current is selected from titanium, tantalum, niobium, zirconium metal or alloys thereof, or the metal or alloy as an electrode substrate, and the electrode substrate is selected from platinum, iridium, ruthenium, and palladium as an electrode catalyst. An insoluble cathode coated with one or more metals, alloys, or metal oxides as an electrode catalyst, or an electrode catalyst dispersion selected from metal oxides of titanium, tin, tantalum, antimony, niobium, and zirconium. An insoluble cathode having a composite oxide coating layer formed therein or an oxygen gas diffusion cathode that reduces oxygen and does not generate hydrogen at the cathode is used, claim 1, claim 2, claim 3, characterized in that 4. An insoluble cathode or oxygen gas for supplying a direct current according to claim 5, claim 6, claim 7, claim 8, and claim 9. Claims 1, 2, and 2 characterized by adjusting the nutrient solution for nutrient solution cultivation and supplying trace elements by electrolyzing the nutrient solution culture solution as an electrolytic solution using a diffusion cathode The preparation of the nutrient solution culture medium and the supply of trace elements according to claim 3, claim 4, claim 5, claim 6, claim 7, claim 8, claim 9 and claim 10. A method for preparing a culture solution for nutrient solution cultivation and a method for supplying a trace element. The soluble electrode is characterized by being a metal or alloy composed of one or more selected from titanium, silicon, aluminum, iron, manganese, zinc, copper, molybdenum, nickel, phosphorus, calcium, magnesium, boron, and carbon. For hydroponics according to claim 1, claim 2, claim 3, claim 4, claim 5, claim 6, claim 7, claim 9, claim 10, and claim 11. A method for preparing a culture solution and a method for supplying trace elements. Culture medium for hydroponics is elemental from nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, carbon, oxygen, hydrogen, iron, manganese, boron, copper, zinc, molybdenum, chlorine, sodium, silicon, aluminum, nickel Composed of an aqueous solution of nitrate, phosphate, sulfate, ammonium salt, organic acid salt, chelate salt, organic fertilizer component, electrolyzing the culture solution for hydroponics as an electrolytic solution, and adjusting the pH to pH 4.5 Claim 1, Claim 2, Claim 3, Claim 4, Claim 5, Claim 6, Claim 7, Claim 8, Claim 9, wherein the pH is adjusted to a range of 8. 13. A method for preparing a culture solution for hydroponics and a method for supplying a trace element according to claim 11 and claim 12. Claim 1, Claim 2, Claim 3, Claim 4, Claim 5, Claim 6, Claim 7, Claim 8, Claim 9, Claim 11, Claim 12, and Claim The power source used in the method for preparing a culture solution for hydroponics and the method for supplying a trace element according to claim 13, wherein the power source is a solar cell, claim 2, characterized in that, Claim 5, Claim 6, Claim 7, Claim 8, Claim 9, Claim 10, Claim 11, Claim 12, and Preparation method and trace element of nutrient solution culture medium of claim 13 Supply method.

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