Apparatus for manufacturing bio-based iron materials, method for manufacturing bio-based iron materials, and bio-based iron materials

Abstract

This invention provides a biological iron material manufacturing apparatus capable of easily producing biological iron materials that satisfy neutral pH and low salt concentration, a method for producing biological iron materials, and biological iron materials themselves. [Solution] A biological iron material manufacturing apparatus comprising: a container for holding an alkaline aqueous solution containing at least one of the high molecular weight organic acids fulvic acid and humic acid; an anode disposed in the container; a cathode disposed in the container; a power supply connecting the anode and the cathode; and a cation exchange member that divides the space inside the container into two parts: an anode-side liquid chamber containing the anode and a cathode-side liquid chamber containing the cathode, wherein the anode is made of a material that contains iron and does not contain any metals with a higher ionization tendency than iron, and the cathode is made of a material that does not dissolve or leach when electricity is applied to the alkaline aqueous solution.

Description

Technical Field

[0001] The present invention relates to an apparatus for manufacturing iron materials for organisms.

Background Art

[0002] In previous research, it has been pointed out that iron may be a limiting factor in the activities of organisms. As an example, it is known that iron-organic acid eluted from forests and supplied from rivers to the ocean plays an important role in the productivity of the ocean. Since iron is an essential element not only for marine organisms but also for all aquatic and terrestrial animals and plants, attention has been focused on the possibility of improving the productivity of organisms with commercial value such as marine products, agricultural crops, freshwater cultured fish, and livestock by supplying iron.

[0003] Regardless of whether they are aquatic or terrestrial, for animals and plants to absorb and utilize iron, it is necessary for iron to be in a water-soluble form. For example, the iron supplied from the above-mentioned forests through rivers to the ocean is known to dissolve in river water by forming a chelate with fulvic acid, which is an amorphous polymer organic acid that is the final product of the decomposition of biomass such as plants by microorganisms such as bacteria.

[0004] As an example of an iron material for organisms that supplies iron to organisms and contains such chelated iron, there is one described in Patent Document 1. The iron-containing material described in Patent Document 1 generates sodium iron citrate by combining sodium hydrogen carbonate with a mixture of citric acid, water, and iron, and further adds lignin sulfonic acid as a chelating agent. This can suppress the oxidation and precipitation of iron ions and provide an iron material for organisms that can supply iron to plants over a long period of time.

Prior Art Documents

Patent Documents

[0006] The biological iron material described in Patent Document 1 is prepared by dissolving iron using citric acid, then adding sodium bicarbonate to adjust the acidity to pH 5-8, and further adding magnesium ligninsulfonate as a chelating agent, resulting in a high salt concentration.

[0007] On the other hand, it is known that the growth conditions for many commercially valuable organisms, such as crops and livestock, are neutral pH and low salt concentration. Therefore, the iron material for biological use described in Patent Document 1 does not meet the suitable growth conditions for organisms, and has problems such as causing stress to organisms and low absorption efficiency by organisms under biological growth conditions.

[0008] Based on the above circumstances, the present invention aims to provide a biological iron material manufacturing apparatus capable of easily producing biological iron materials that satisfy neutral pH and low salt concentration, a method for manufacturing biological iron materials, and biological iron materials. [Means for solving the problem]

[0009] To solve the above problems, one aspect of the present invention includes the following:

[0010] [1] A biological iron material manufacturing apparatus for supplying iron to living organisms, comprising: a container for holding an alkaline aqueous solution containing at least one of fulvic acid, humic acid, and a high molecular weight organic acid extracted from biomass; an anode disposed in the container; a cathode disposed in the container; a power supply connecting the anode and the cathode; and a cation exchange member that divides the space inside the container into two parts: an anode-side liquid chamber containing the anode and a cathode-side liquid chamber containing the cathode, wherein the anode is made of a material that contains iron and does not contain a metal with a higher ionization tendency than iron, and the cathode is made of a material that does not dissolve or leach when electricity is applied to the alkaline aqueous solution.

[0011] [2] The apparatus for manufacturing bio-based iron materials according to [1], wherein the cathode is made of stainless steel.

[0012] [3] A biological iron material manufacturing apparatus according to [1] or [2], comprising an aeration pipe for supplying air into the solution in the anode side liquid chamber within the container.

[0013] [4] The cation exchange member is a cation exchange membrane, and the apparatus for manufacturing iron materials for biological use according to any one of [1] to [3].

[0014] [5] A biological iron material manufacturing apparatus according to any one of [1] to [4], comprising a discharge and supply device located in the cathode-side liquid chamber of the container, which discharges the treated alkaline aqueous solution and supplies the unreacted alkaline aqueous solution.

[0015] [6] A biological iron material manufacturing apparatus according to any one of [1] to [5], comprising a solid material discharge section for discharging the precipitated biological iron material from the anode side liquid chamber.

[0016] [7] A biological iron material manufacturing apparatus according to any one of [1] to [6], comprising a liquid material discharge section for discharging the biological iron material dissolved in the alkaline aqueous solution from the anode side liquid chamber.

[0017] [8] A biological iron material manufacturing apparatus according to any one of [1] to [7], further comprising an alkaline aqueous solution supply unit for supplying the untreated alkaline aqueous solution in addition to the liquid material discharge unit in the anode side liquid chamber.

[0018] [9] A biological iron material manufacturing apparatus according to any one of [1] to [8], comprising a control device that generates and supplies control signals to control the operation of each component of the biological iron material manufacturing apparatus.

[0019]

[10] A method for producing an iron material for organisms, comprising using an anode containing iron and not containing a metal with a greater ionization tendency than iron, and a cathode made of a material that does not dissolve or elute during energization, and performing a step of energizing an alkaline aqueous solution containing at least one of fluvo acid, humic acid, and a high molecular weight organic acid extracted from biomass. The alkaline aqueous solution is stored in a container divided into two liquid chambers via a cation exchange member, the anode is disposed in one liquid chamber, and the cathode is disposed in the other liquid chamber. The alkaline aqueous solution is obtained by extracting the high molecular weight organic acid from biomass. In the step of energizing, energization is performed until the pH and salt concentration of the alkaline aqueous solution in the liquid chamber where the anode is installed reach a preset target value.

[0020]

[11] The method for producing an iron material for organisms according to

[10] , wherein air is supplied to the liquid chamber where the anode is disposed.

[0021]

[12] The method for producing an iron material for organisms according to

[10] or

[11] , wherein the treated alkaline aqueous solution is discharged from the liquid chamber where the cathode is disposed, and the unreacted alkaline aqueous solution is supplied.

[0022]

[13] The method for producing an iron material for organisms according to any one of

[10] to

[12] , wherein the precipitated iron material for organisms is discharged from the liquid chamber where the anode is disposed.

[0023]

[14] The method for producing an iron material for organisms according to any one of

[10] to

[13] , wherein the iron material for organisms dissolved in the alkaline aqueous solution is discharged from the liquid chamber where the anode is disposed.

[0024]

[15] The method for producing an iron material for organisms according to any one of

[10] to

[14] , wherein in addition to discharging the iron material for organisms dissolved in the alkaline aqueous solution from the liquid chamber where the anode is disposed, the untreated alkaline aqueous solution is supplied.

[0025]

[17] An aqueous iron material for organisms, containing iron chelated by a polymeric organic acid extracted from biomass, which is fulvic acid or soluble in water under neutral and acidic conditions, having a pH of 4 or more and 10 or less, and an electrical conductivity of 100 μS / cm or less.

[0026]

[18] A solid iron material for organisms, containing iron chelated by a polymeric organic acid extracted from biomass, which is humic acid or insoluble in water under neutral and acidic conditions.

Advantages of the Invention

[0027] According to the present invention, it is possible to provide an apparatus for manufacturing an iron material for organisms that satisfies neutral pH and low salt concentration, and a method for manufacturing an iron material for organisms.

Brief Description of the Drawings

[0028] [Figure 1] It is a schematic diagram of an apparatus for manufacturing an iron material for organisms according to an embodiment of the present invention. [Figure 2] It is a schematic diagram of a preferred arrangement of the anode-side liquid chamber, the cathode-side liquid chamber, and the cation exchange member in the apparatus for manufacturing an iron material for organisms according to an embodiment of the present invention. [Figure 3] It is a graph showing the relationship between the pH and ion concentration of the alkaline aqueous solution in the anode-side liquid chamber and the energization time during the operation of the apparatus for manufacturing an iron material for organisms according to an embodiment of the present invention. [Figure 4] It is a schematic diagram of a polymeric organic acid extraction apparatus for immersing biomass in an alkaline aqueous solution and extracting a polymeric organic acid according to an embodiment of the present invention. [Figure 5] It is a schematic diagram of a manufacturing system for generating an iron material for organisms using a polymeric organic acid extracted with an alkaline aqueous solution according to an embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0029] An embodiment of the present invention will be described with reference to FIGS. 1 to 5. In all the following drawings, for the sake of clarity, the dimensions and ratios of each component are appropriately different.

[0030] Furthermore, the embodiments shown below illustrate configurations for realizing the technical concept of the present invention, and the technical concept of the present invention is not limited by the material, shape, and structure of the components described below. Various modifications can be made to the technical concept of the present invention within the technical scope defined by the claims described in the claims.

[0031] Figure 1 is a schematic diagram of a biological iron material manufacturing apparatus 10 according to this embodiment. The biological iron material manufacturing apparatus 10 comprises a container 12, an anode 21, a cathode 22, a power supply 23, a cation exchange member 30, an aeration pipe 50, a stirring unit 60, a discharge supply device 70, a solid material discharge unit 80, a liquid material discharge unit 90, and a control device 300. The space inside the container 12 is divided into an anode-side liquid chamber 31 and a cathode-side liquid chamber 32. One or more of the aeration pipe 50, stirring unit 60, discharge supply device 70, solid material discharge unit 80, liquid material discharge unit 90, and control device 300 may be omitted.

[0032] (container) Container 12 holds an alkaline aqueous solution 40 containing at least one of fulvic acid, humic acid, and a high-molecular-weight organic acid extracted from biomass. Any known material can be used for container 12, as long as it does not dissolve in the alkaline aqueous solution 40 and does not dissolve due to changes in the pH and ion concentration of the alkaline aqueous solution 40, as described later.

[0033] (Alkaline solution) Alkaline aqueous solution 40 is an aqueous solution containing at least one of naturally occurring polymers, fulvic acid and humic acid, and a polymeric organic acid extracted from biomass under alkaline conditions. Biomass contains polymeric organic acids, and it is known that these polymeric organic acids can be extracted using an alkaline aqueous solution. As alkaline aqueous solution 40, an aqueous solution containing polymeric organic acids extracted from biomass using an alkaline aqueous solution can be used. The aqueous solution from which polymeric organic acids have been extracted from biomass may be used as alkaline aqueous solution 40 at its original concentration, or it may be used as alkaline aqueous solution 40 after adjusting its concentration and pH.

[0034] Examples of biomass include, but are not limited to, forest humus, river, dam and lake bottom sediment, and artificial humus such as compost. Examples of aqueous solutions that can be used to extract high molecular weight organic acids from biomass include, but are not limited to, sodium hydroxide aqueous solution and potassium hydroxide aqueous solution.

[0035] (anode) The anode 21 is an electrode placed inside the container 12. The anode 21 is an electrode made of a material that contains iron but does not contain any metals with a higher ionization tendency than iron. Examples of the anode 21 include, but are not limited to, electrodes made entirely of metallic iron or electrodes formed from iron-containing waste materials. Examples of "iron-containing waste materials" include mineral waste sand used in metal processing.

[0036] (cathode) The cathode 22 is an electrode placed inside the container 12. The material of the cathode 22 can be one that does not dissolve or leach when current is passed through the alkaline aqueous solution 40. Examples of materials for the cathode 22 include carbon rods and platinum, but stainless steel is preferred due to its cost.

[0037] (power supply) Power supply 23 is a DC power supply that connects the anode 21 and cathode 22. While any known power supply can be used, one that allows adjustment of voltage, current, and operating time is preferable.

[0038] (Cation exchange component) The cation exchange member 30 divides the space inside the container 12 into two parts: an anode-side liquid chamber 31 where the anode 21 is located, and a cathode-side liquid chamber 32 where the cathode 22 is located. The cation exchange member 30 may be arranged in such a way that it divides the space inside the container 12 into an inner and outer section. Among these, the arrangement shown in Figure 2, where the outer section is the anode-side liquid chamber 31 and the inner section is the cathode-side liquid chamber 32, is particularly preferred.

[0039] In Figure 2, the bottom of the cathode-side liquid chamber 32 is shown to be spaced apart from the bottom of the container 12, but this is not the only option. The bottom of the cathode-side liquid chamber 32 may be in contact with the bottom of the container 12.

[0040] As the cation exchange member 30, any known material can be used, as long as it has cation exchange capacity or selective permeability to cations and prevents mixing of the alkaline aqueous solution 40 held in the anode-side liquid chamber 31 and the cathode-side liquid chamber 32, respectively. Examples of possible configurations for the cation exchange member include a cation exchange membrane and a cation exchange resin filled between two ion-permeable partitions, but a cation exchange membrane is preferred among these.

[0041] When sodium hydroxide is used in the aqueous solution for extracting the polymeric organic acid, a sodium exchange type cation exchange resin is preferred, but is not limited thereto.

[0042] (Operation instructions) In the following, the operation of the biological iron material manufacturing apparatus 10 will be described by dividing it into the reaction in the anode-side liquid chamber 31, the reaction in the cathode-side liquid chamber 32, and the movement of ions between the anode-side liquid chamber 31 and the cathode-side liquid chamber 32.

[0043] (Reaction in the anode-side liquid chamber 31) When an electric current is passed through the alkaline aqueous solution 40, the iron constituting the anode 21 is oxidized and dissolves in the alkaline aqueous solution 40 as iron ions. The iron ions dissolved in the alkaline aqueous solution 40 in the anode-side liquid chamber 31 combine with hydroxide ions in the alkaline aqueous solution 40 and precipitate as iron hydroxide. As a result, the hydroxide ion concentration in the anode-side liquid chamber 31 decreases, and the pH drops.

[0044] When the concentration of hydroxide ions in the anode-side liquid chamber 31 decreases due to the precipitation of iron hydroxide, the iron ions supplied by the anode 21 form a complex with the polymeric organic acid. If the polymeric organic acid is humic acid, it precipitates as a solid as the pH of the alkaline aqueous solution 40 decreases. On the other hand, if the polymeric organic acid is fulvic acid, it remains dissolved even after the pH of the alkaline aqueous solution 40 decreases.

[0045] (Reaction in the cathode-side liquid chamber 32) On the other hand, when an electric current is passed through the alkaline aqueous solution 40, the water in the alkaline aqueous solution 40 around the cathode 22 is reduced, generating hydrogen gas and hydroxide ions. As a result, the hydroxide ion concentration in the alkaline aqueous solution 40 in the cathode-side liquid chamber 32 increases, and the pH rises.

[0046] (Ion movement between liquid chambers) As a result of the above operations, the hydroxide ion concentration in the cathode-side liquid chamber 32 increases, disrupting the charge balance. However, hydroxide ions cannot move to the anode-side liquid chamber 31 on their own due to the cation exchange member 30. Therefore, the charge imbalance in the cathode-side liquid chamber 32 is resolved in proportion to the amount of cations that move from the anode-side liquid chamber 31 to the cathode-side liquid chamber 32, and the electrical conductivity (EC value) of the anode-side liquid chamber 31 decreases.

[0047] Furthermore, if the hydroxide ion concentration in the cathode-side liquid chamber 32 is lower than that in the anode-side liquid chamber 31, a migration of cation hydroxide occurs from the anode-side liquid chamber 31 to the cathode-side liquid chamber 32 in proportion to the concentration difference, and the pH and ion concentration in the anode-side liquid chamber 31 decrease accordingly. This decrease in ion concentration leads to a decrease in the electrical conductivity (EC value) of the anode-side liquid chamber 31.

[0048] Therefore, the biological iron material manufacturing apparatus 10 can control the amount of iron ions that dissolve from the anode 21 into the alkaline aqueous solution 40 in the anode-side liquid chamber 31 by controlling the voltage, current, and energizing time during energization. The pH and ion concentration of the alkaline aqueous solution 40 in the anode-side liquid chamber 31 decrease according to the amount of iron ions that precipitate as iron hydroxide, the amount that moves from the anode-side liquid chamber 31 to the cathode-side liquid chamber 32 as cation hydroxide, and the amount that moves from the anode-side liquid chamber 31 to the cathode-side liquid chamber 32 as cations. Therefore, the biological iron material manufacturing apparatus 10 can adjust the pH and ion concentration of the alkaline aqueous solution 40 in the anode-side liquid chamber 31 to a preset target value.

[0049] Figure 3 shows an example of the relationship between the pH and ion concentration of the alkaline aqueous solution 40 in the anode-side liquid chamber 31 and the energizing time during the operation of the biological iron material manufacturing apparatus 10. The horizontal axis represents the energizing time, the vertical axis (first axis) represents the ion concentration (μS / cm), and the vertical axis (second axis) represents the pH. The curve on the right shows the change in pH over time, and the curve on the left shows the change in ion concentration over time. From Figure 3, it can be seen that when the biological iron material manufacturing apparatus 10 is operated, the pH and ion concentration of the alkaline aqueous solution 40 change according to the energizing time, and that the pH and ion concentration decrease as the energizing time increases.

[0050] This trend is likely to be the same even if the type or lot of the alkaline aqueous solution 40 is changed. Therefore, when operating the biological iron material manufacturing apparatus 10, it is advisable to confirm the relationship between the energizing time and the pH and ion concentration of the alkaline aqueous solution 40, as shown in Figure 3, through preliminary experiments. By doing so, when using the biological iron material manufacturing apparatus 10, the energizing can be stopped when the pH and ion concentration reach the predetermined target values, thereby obtaining biological iron material with the target pH and ion concentration.

[0051] The target values ​​are not particularly limited as long as they are lower than the pH and ion concentration of the alkaline aqueous solution 40 before the start of current flow. However, considering use on crops and livestock, for example, the pH is preferably 4 to 10, more preferably 4 to 9, and even more preferably 4 to 8. The ion concentration is preferably such that the electrical conductivity is 100 μS / cm or less.

[0052] If the cation exchange member 30 is an ion exchange membrane, the incoming cations are thought to be mainly cations derived from the alkaline compound used for organic acid extraction in the alkaline aqueous solution 40 in the anode-side liquid chamber 31 that have permeated through the cation exchange membrane. For example, if an aqueous sodium hydroxide solution is used for organic acid extraction, the incoming cations are thought to be mainly sodium ions.

[0053] If the cation exchange member 30 is made of two ion-permeable partition walls filled with cation exchange resin, it is thought that the incoming cations are mainly eluted from the cation exchange resin through exchange with cations in the anode-side liquid chamber 31.

[0054] (Separation of bio-based iron materials) As described above, the solubility of the organic iron acid generated in the anode-side liquid chamber 31 varies depending on the pH, and the pH and ion concentration in the anode-side liquid chamber 31 can be adjusted. Therefore, in this invention, the generated bio-grade iron material can be separated and recovered as needed depending on the type of polymeric organic acid.

[0055] (Aeration pipe) The aeration pipe 50 is placed inside the anode-side liquid chamber 31. The aeration pipe 50 supplies an oxygen-containing gas to the alkaline aqueous solution inside the anode-side liquid chamber 31. The "oxygen-containing gas" may be oxygen alone or an oxygen-containing gas mixture. The oxygen-containing gas mixture may be air or an air mixture with adjusted composition. Among these, air is preferred as the oxygen-containing gas because it is low-cost.

[0056] The gas supplied by the aeration pipe 50 oxidizes the iron ions in the alkaline aqueous solution 40 in the anode-side liquid chamber 31 from divalent to trivalent, promoting the formation of iron oxide precipitate. By promoting the formation of iron oxide precipitate, hydroxide ions can be removed more efficiently from the alkaline aqueous solution 40 in the anode-side liquid chamber 31, thereby accelerating the decrease in pH and ion concentration.

[0057] The supply of gas through the aeration pipe 50 begins after the energization of the alkaline aqueous solution 40 is started. The amount of gas supplied by the aeration pipe 50 should ideally be such that the dissolved oxygen concentration in the alkaline aqueous solution 40 remains close to the saturation point, and does not interfere with the energization of the alkaline aqueous solution 40. It is advisable to confirm this gas supply amount in advance through preliminary experiments. When operating the apparatus, the gas supply amount should be determined based on the results of the preliminary experiments.

[0058] (Agitation section) The stirring unit 60 is positioned within the anode-side liquid chamber 31. The stirring unit 60 promotes the reaction of iron ions and complex formation within the anode-side liquid chamber 31 by stirring the alkaline aqueous solution 40 in the anode-side liquid chamber 31. In addition to the stirring blade type stirrer shown in the figure, the stirring unit 60 can employ any known configuration that can cause the alkaline aqueous solution 40 to flow and be stirred within the container 12.

[0059] (Discharge supply device) The discharge and supply device 70 discharges the alkaline aqueous solution 40 in the cathode-side liquid chamber 32 and supplies the untreated alkaline aqueous solution 40 to the cathode-side liquid chamber 32. "Untreated alkaline aqueous solution 40" means that the above-mentioned reaction that occurs in the cathode-side liquid chamber 32 when the biological iron material manufacturing apparatus 10 is operated has not yet occurred, that is, the alkaline aqueous solution 40 has not been treated by the biological iron material manufacturing apparatus 10.

[0060] The discharge and supply device 70 includes a supply pipe 71 that supplies unreacted alkaline aqueous solution 40 from outside the biological iron material manufacturing apparatus 10 into the cathode side liquid chamber 32, a discharge pipe 72 that discharges the treated alkaline aqueous solution 40 from inside the cathode side liquid chamber 32 to the outside, and a pump unit 73 that exchanges the alkaline aqueous solution 40 with the outside through the supply pipe 71 and the discharge pipe 72.

[0061] When power is applied, the hydroxide ion concentration in the alkaline aqueous solution 40 in the cathode-side liquid chamber 32 increases due to hydroxide ions generated by the reduction of water at the cathode 22. In contrast, when power is applied, the hydroxide ion concentration in the alkaline aqueous solution 40 in the anode-side liquid chamber 31 decreases due to the precipitation of iron hydroxide, as described above. However, since the cathode-side liquid chamber 32 and the anode-side liquid chamber 31 are separated by the cation exchange member 30, hydroxide ions have difficulty moving from the cathode-side liquid chamber 32 to the anode-side liquid chamber 31. As a result, when power is applied, the hydroxide ion concentration decreases in the alkaline aqueous solution 40 in the anode-side liquid chamber 31, and increases in the alkaline aqueous solution 40 in the cathode-side liquid chamber 32.

[0062] The reaction at the cathode 22 maintains the electrical neutrality of the alkaline aqueous solution 40 in the cathode-side liquid chamber 32 by the movement of cations from the anode-side liquid chamber 31 via the cation exchange member 30. Furthermore, between the anode-side liquid chamber 31 and the cathode-side liquid chamber 32, cationic hydroxides move in a direction that mitigates the hydroxide concentration difference between the two liquid chambers. Specifically, under conditions of high hydroxide ion concentration in the anode-side liquid chamber 31, cationic hydroxides move to the cathode-side liquid chamber 32. Under conditions of low hydroxide ion concentration in the anode-side liquid chamber 31, cationic hydroxides move to the anode-side liquid chamber 31. As a result, the decrease in pH and EC of the anode-side liquid chamber 31 is suppressed.

[0063] In the absence of the discharge supply device 70, there is no means to suppress the increase in the hydroxide ion concentration of the alkaline aqueous solution 40 in the cathode-side liquid chamber 32. Therefore, the rate of decrease in the hydroxide concentration and cation concentration in the anode-side liquid chamber 31 is limited by the increase in the hydroxide ion concentration in the cathode-side liquid chamber 32.

[0064] In contrast, the biological iron material manufacturing apparatus 10 shown in Figure 1 is equipped with a discharge and supply device 70. The discharge and supply device 70 discharges the alkaline aqueous solution 40 in the cathode-side liquid chamber 32, in which the hydroxide ion concentration has increased, and supplies untreated alkaline aqueous solution 40, thereby suppressing the increase in hydroxide ion concentration of the alkaline aqueous solution 40 in the cathode-side liquid chamber 32 that occurs with the reaction at the cathode 22.

[0065] This suppresses the movement of cation hydroxides from the alkaline aqueous solution 40 in the cathode-side liquid chamber 32 to the anode-side liquid chamber 31, thereby promoting a decrease in the hydroxide concentration and cation concentration (EC value) in the anode-side liquid chamber 31.

[0066] In Figure 1, the discharge supply device 70 is shown to be located at the bottom of the container 12, but this is not the only option. The discharge supply device 70 can be installed in any location that allows for the replacement of the alkaline aqueous solution 40 in the cathode-side liquid chamber 32.

[0067] (Solid material discharge section) The solid material discharge section 80 discharges the solid iron humicate that has precipitated in the anode-side liquid chamber 31 from the bottom of the anode-side liquid chamber 31. The solid material discharge section 80 is, for example, a device that discharges the precipitate from the bottom of the anode-side liquid chamber 31. Known techniques for removing precipitates in water may be used for the solid material discharge section 80.

[0068] The solid precipitated in the anode-side liquid chamber 31 may contain iron hydroxide in addition to iron humic acid. The solid material discharge section 80 may include a configuration for separating iron humic acid and iron hydroxide from the discharged solid, but this is not required.

[0069] (Liquid material discharge section) The liquid material discharge section 90 discharges iron fulvic acid, which reacts with iron to form a chelate and is dissolved in the alkaline aqueous solution 40, from inside the anode-side liquid chamber 31. The liquid material discharge section 90 is, for example, a pump that pumps out the alkaline aqueous solution 40 from inside the anode-side liquid chamber 31. Known techniques for discharging the aqueous solution from inside the container 12 may be used for the liquid material discharge section 90.

[0070] In addition to the liquid material discharge unit 90, an alkaline aqueous solution supply unit (not shown) for supplying untreated alkaline aqueous solution 40 may be provided. The alkaline aqueous solution supply unit can be placed at any position that allows for the supply of alkaline aqueous solution 40 into the anode-side liquid chamber 31. By supplying untreated alkaline aqueous solution 40, the amount of alkaline aqueous solution 40 that has decreased due to the discharge of iron fulvic acid can be replenished.

[0071] (Control device) The control device 300 generates and supplies control signals to control the operation of each component of the biological iron material manufacturing apparatus 10. The control device 300 may store the relationship between the energizing time when the alkaline aqueous solution 40 is energized under predetermined conditions and the pH and ion concentration of the alkaline aqueous solution 40, and calculate the energizing time by inputting the target pH and ion concentration.

[0072] As a result, when the user of the biological iron material manufacturing apparatus 10 inputs a target value into the control device 300, the control device 300 calculates the energizing time for the alkaline aqueous solution 40 to satisfy the target value, and after the energizing time has elapsed, it can control the power supply 23 to terminate the energizing.

[0073] Alternatively, the control device 300 may use sensors to measure the pH and ion concentration of the alkaline aqueous solution 40, and control the power supply 23 to terminate the power supply after the measured values ​​reach the target values.

[0074] In addition, the control device 300 can control the operation of the biological iron material manufacturing apparatus 10 by controlling the aeration pipe 50, the stirring unit 60, the discharge supply device 70, the solid material discharge unit 80, and the liquid material discharge unit 90.

[0075] (Manufacturing System) The above-described bio-based iron material manufacturing apparatus 10 may also process a separately prepared alkaline aqueous solution 40, and may constitute part of a manufacturing system for producing bio-based iron materials from biomass. In the manufacturing system, for example, bio-based iron materials are produced from biomass by using in succession an apparatus for producing an alkaline aqueous solution 40 from biomass and the above-described bio-based iron material manufacturing apparatus 10.

[0076] Figure 4 shows a schematic diagram of an apparatus for producing an alkaline aqueous solution 40, that is, a polymer organic acid extraction apparatus that extracts polymer organic acids from biomass by immersing biomass in an alkaline aqueous solution. The polymer organic acid extraction apparatus 200 has a reaction vessel 210, an alkaline aqueous solution supply unit 220, a biomass supply unit 230, and a generated solution discharge unit 260.

[0077] The reaction vessel 210 holds the alkaline aqueous solution 240 and the biomass 250. A known material that does not dissolve in the alkaline aqueous solution can be used for the material of the reaction vessel 210.

[0078] The alkaline aqueous solution supply unit 220 supplies the alkaline aqueous solution 240 into the reaction vessel 210. The alkaline aqueous solution supply unit 220 can be arranged in any configuration as long as it can supply the alkaline aqueous solution 240 into the reaction vessel 210. Any known technology capable of supplying the alkaline aqueous solution 240 to be used into the reaction vessel 210 can be used for the alkaline aqueous solution supply unit 220.

[0079] Alkaline aqueous solution 240 is an alkaline aqueous solution that does not contain high molecular weight organic acids. Examples of alkaline aqueous solution 240 include, but are not limited to, sodium hydroxide aqueous solution and potassium hydroxide aqueous solution.

[0080] The biomass supply unit 230 supplies biomass 250 into the reaction vessel 210. The biomass 250 can be any of the biomass described above. The arrangement of the biomass supply unit 230 can be any arrangement as long as it can supply biomass 250 into the reaction vessel 210. Any known technology capable of supplying the biomass 250 into the reaction vessel 210 can be used for the biomass supply unit 230.

[0081] Biomass 250 is biomass containing high-molecular-weight organic acids. Examples of Biomass 250 include, but are not limited to, forest humus, river and dam bottom sediment and lake bottom sediment, and artificial humus such as compost.

[0082] The biomass 250 supplied by the biomass supply unit 230 is immersed in the alkaline aqueous solution 240 supplied by the alkaline aqueous solution supply unit 220 within the reaction vessel 210. This allows for the extraction of high molecular weight organic acids contained in the biomass 250 into the alkaline aqueous solution 240.

[0083] The alkaline aqueous solution 240 from which the high molecular weight organic acid has been extracted (i.e., the alkaline aqueous solution 40 described above) can be removed via the generated solution discharge section 260. Known techniques for discharging aqueous solutions or liquids can be used in the generated solution discharge section. The generated solution discharge section 260 may also include known techniques such as a filtration device or a sedimentation tank for removing unwanted impurities dispersed in the alkaline aqueous solution 240.

[0084] Figure 5 shows a schematic diagram of a manufacturing system for producing bio-grade iron materials using high-molecular-weight organic acids extracted with an alkaline aqueous solution. The manufacturing system 100 includes a high-molecular-weight organic acid extractor 200 and a bio-grade iron material manufacturing apparatus 10. The alkaline aqueous solution 240 (i.e., the alkaline aqueous solution 40 mentioned above) containing high-molecular-weight organic acids produced in the high-molecular-weight organic acid extractor 200 is supplied to the bio-grade iron material manufacturing apparatus 10 and used there to produce bio-grade iron materials.

[0085] <Method for manufacturing bio-based iron materials> Next, we will explain the manufacturing method for bio-based iron materials. A method for producing iron materials for biological use includes a step of passing an electric current through an alkaline aqueous solution containing at least one of two high-molecular-weight organic acids, fulvic acid and humic acid, using an anode and a cathode whose surfaces are made of metallic iron.

[0086] As an example, a method for producing bio-based iron materials may include the steps of: extracting high-molecular-weight organic acids from biomass under alkaline conditions to obtain an alkaline aqueous solution containing at least one of high-molecular-weight organic acids, fulvic acid and humic acid; storing the alkaline aqueous solution in a container divided into a liquid chamber where an anode made of iron is located and a liquid chamber where a cathode is located, via a cation exchange member; and reacting the alkaline aqueous solution with iron to produce bio-based iron materials by applying an electric current to the alkaline aqueous solution until the pH and ion concentration of the alkaline aqueous solution in the liquid chamber where the anode is located reach a predetermined target value.

[0087] (Extraction of high molecular weight organic acids) First, prepare the biomass from which high-molecular-weight organic acids are extracted. Examples of biomass include, but are not limited to, forest humus, river, dam, and lake bottom sediment, and artificial humus such as compost.

[0088] Next, an alkaline aqueous solution (the alkaline aqueous solution 240 described above) is prepared for extracting high molecular weight organic acids from biomass. Examples of alkaline aqueous solutions include, but are not limited to, sodium hydroxide aqueous solution and potassium hydroxide aqueous solution. By immersing biomass in the alkaline aqueous solution and dissolving the soluble components, high molecular weight organic acids such as fulvic acid and humic acid can be extracted into the aqueous solution, thereby obtaining an alkaline aqueous solution (the alkaline aqueous solution 40 described above) containing high molecular weight organic acids.

[0089] It is presumed that the insoluble impurities remaining in the alkaline aqueous solution after extracting high molecular weight organic acids from biomass include high molecular weight organic acid components that are insoluble in alkali. These alkali-insoluble impurities may be removed by known methods such as filtration and precipitation, or they may be used in the process of producing bio-based iron materials, as described later.

[0090] (Generation of bio-based iron materials) In the process of producing bio-grade iron materials, a manufacturing apparatus is used to electrically supply iron ions to an alkaline aqueous solution containing a high-molecular-weight organic acid. This apparatus precipitates hydroxide ions in the alkaline aqueous solution as iron hydroxide and simultaneously forms chelates between the high-molecular-weight organic acid and iron ions in the alkaline aqueous solution, thereby producing bio-grade iron materials. An example of such a manufacturing apparatus is, but is not limited to, the bio-grade iron material manufacturing apparatus 10.

[0091] (Biological iron materials produced) The bio-ferrous iron material produced in this reaction is created by precipitating hydroxide ions from the alkaline aqueous solution used to extract high-molecular-weight organic acids as iron hydroxide. As a result, the pH and ion concentration of the alkaline aqueous solution decrease in proportion to the time the bio-ferrous iron material production reaction takes place. Therefore, by continuing the bio-ferrous iron material production reaction until the pH and ion concentration of the bio-ferrous iron material reach predetermined target values, it is possible to produce bio-ferrous iron material that is less stressful for organisms or has high absorption efficiency.

[0092] (Fractionalization of iron materials for biological use) In the process of fractionating iron materials for biological use, the materials are fractionated based on their solubility in high-molecular-weight organic acids. Iron humic acid precipitates as a solid under neutral and acidic conditions, while iron fulvic acid remains water-soluble and dissolved in aqueous solutions under the same conditions. Therefore, iron humic acid can be fractionated by recovering the solid in the manufacturing equipment, and iron fulvic acid can be fractionated by recovering the aqueous solution.

[0093] Bio-grade iron materials can be manufactured, for example, by the methods described above.

[0094] Furthermore, in the above-described method for producing iron materials for biological use, air may be supplied to the liquid chamber where the anode is located. This oxidizes the iron ions in the alkaline aqueous solution in the liquid chamber where the anode is located from divalent to trivalent, promoting the formation of iron oxide precipitate. By promoting the formation of iron oxide precipitate, hydroxide ions can be removed more efficiently from the alkaline aqueous solution in the liquid chamber on the anode side, thereby promoting a decrease in pH and ion concentration.

[0095] Furthermore, in the above-mentioned method for manufacturing the bio-based iron material, the treated alkaline aqueous solution may be discharged from the liquid chamber where the cathode is located, and the untreated alkaline aqueous solution may be supplied to the liquid chamber where the cathode is located.

[0096] As explained in the above description of the operation of the biological iron material manufacturing apparatus 10, in the liquid chamber where the cathode is located, the hydroxide ion concentration of the alkaline aqueous solution increases due to the hydroxide ions generated by the reduction of water at the cathode. Therefore, by replacing the alkaline aqueous solution in the liquid chamber on the cathode side with an untreated alkaline aqueous solution, the increase in the hydroxide ion concentration of the alkaline aqueous solution in the liquid chamber on the cathode side can be suppressed. This promotes the movement of cations to the liquid chamber on the cathode side via the cation exchange member, and improves the rate of decrease in pH and ion concentration in the liquid chamber 31 on the anode side.

[0097] (Iron materials for solid biological applications) The solid biological iron material of the present invention is a solid containing iron chelated with humic acid, and is a solid biological iron material in which humic acid and iron are uniformly dispersed. Conventionally, humic acid is known to be usable as an agricultural fertilizer. Furthermore, as mentioned above, iron is attracting attention for its potential to contribute to improving the productivity of commercially valuable organisms such as marine products and agricultural crops. The solid biological iron material of this embodiment can be used as an iron material containing humic acid and iron.

[0098] Furthermore, as described above, the solid biological iron material of this embodiment forms a precipitate in an aqueous solution. This precipitate is thought to be the result of humic acid and iron taking a stable form in the aqueous solution. Moreover, it is thought that humic acid and iron precipitate in an aqueous solution at a constant reaction ratio. Therefore, the resulting solid biological iron material is thought to have humic acid and iron uniformly dispersed and maintain a stable state. In such a solid biological iron material, compared to a mixed sample prepared by separately preparing and mixing humic acid and iron, for example, it is thought that iron and humic acid remain stable without separating during storage, making it possible to use it as an iron material that always contains humic acid and iron in a constant ratio.

[0099] Such biological iron materials can be used, for example, as feed additives or as iron-supplying materials in the ocean, but are not limited to these uses.

[0100] (Iron materials for aqueous biological applications) The present invention relates to an aqueous biological iron material containing iron chelated with fulvic acid (iron fulvic acid). The pH and salt concentration of the present invention's aqueous biological iron material can be adjusted to any value, but considering its use in crops and livestock, for example, a pH of 4 to 10 and a salt concentration such that the electrical conductivity is 100 μS / cm or less are preferred. Such a biological iron material can be used, for example, as a hydroponic fertilizer or a foliar spray, but is not limited to these applications.

[0101] Preferred embodiments of the present invention have been described above with reference to the attached drawings, but the present invention is not limited to these examples. The shapes and combinations of the constituent members shown in the above examples are merely examples, and can be modified in various ways based on design requirements, etc., without departing from the spirit of the present invention. [Examples]

[0102] <Example 1> Riverbed sediment was prepared as biomass. The biomass was immersed in a 0.1 mol / L sodium hydroxide aqueous solution at 20°C for several days, and solid-liquid separation was repeated to obtain an alkaline aqueous solution of high molecular weight organic acid. The pH of this solution was 12.5, and the EC value was 1700 μS / cm.

[0103] Next, in a manufacturing apparatus, iron ions were electrically supplied to an alkaline aqueous solution containing a high molecular weight organic acid, and a reaction was carried out to produce iron material for biological use while precipitating excess hydroxide ions as iron hydroxide. The power supply voltage was 20V and the current was 0.1~0.3A.

[0104] The following evaluations were conducted on the obtained bio-based iron materials.

[0105] <Measurement of time-dependent changes in pH and ion concentration of alkaline aqueous solutions> The pH and ion concentration of an alkaline aqueous solution containing a high-molecular-weight organic acid supplied to the manufacturing apparatus were measured over time, and the relationship between the time required for the reaction to produce the bio-grade iron material and the pH and ion concentration of the alkaline aqueous solution was determined. The results are shown in Figure 3.

[0106] <Measuring iron concentration after aqua regia decomposition> The solution from the reaction was centrifuged to obtain the supernatant solution of the biological iron material. The supernatant solution was subjected to aqua regia decomposition, and the dissolved iron concentration was quantified by atomic absorption spectrometry as a nitric acid solution.

[0107] Measurement results confirmed the dissolution of 50-150 mg Fe / L of iron in the aqueous solution of the bio-based iron material of the present invention. Since the concentration of iron treated with aqua regia in soil solution (20 kg / 10a) under standard soil fertilization conditions for iron sulfate is approximately 0.5-1 mg Fe / L, it was confirmed that the aqueous solution of the present invention can dissolve a larger amount of iron compared to conventional bio-based iron materials. [Explanation of Symbols]

[0108] 10...Biological iron material manufacturing apparatus, 12...Container, 21...Anode, 22...Cathode, 23...Power supply, 30...Cation exchange component, 40...Alkaline aqueous solution, 50...Aeration pipe, 60...Agitation section, 70...Discharge supply device, 71...Supply pipe, 72...Discharge pipe, 73...Pump section, 80...Solid material discharge section, 90...Liquid material discharge section, 200...High molecular weight organic acid extraction apparatus, 210...Reaction vessel, 220...Alkaline aqueous solution supply section, 230...Biomass supply section, 240...Alkaline aqueous solution, 250...Biomass, 260...Produced solution discharge section, 300...Control device, 100...Manufacturing system

Claims

1. A biological iron material manufacturing apparatus for producing biological iron materials that supply iron to living organisms, A container for holding an alkaline aqueous solution containing at least one of fulvic acid, humic acid, and a high molecular weight organic acid extracted from biomass, The anode placed inside the container, A cathode placed inside the aforementioned container, A power supply connecting the anode and the cathode, A cation exchange member divides the space inside the container into two parts: an anode-side liquid chamber containing the anode and a cathode-side liquid chamber containing the cathode. Equipped with, A biological iron material manufacturing apparatus, wherein the anode is made of a material that contains iron and does not contain any metals with a higher ionization tendency than iron, and the cathode is made of a material that does not dissolve or leach when an electric current is passed through the alkaline aqueous solution.

2. The apparatus for producing iron materials for biological use according to claim 1, wherein the cathode is made of stainless steel.

3. The apparatus for producing biological iron materials according to claim 1, further comprising an aeration pipe for supplying air to the alkaline aqueous solution, which is held in the anode-side liquid chamber within the container.

4. The apparatus for producing biological iron materials according to claim 1 or 3, wherein the cation exchange member is a cation exchange membrane.

5. The biological iron material manufacturing apparatus according to claim 1 or 3, further comprising a discharge and supply device that discharges the treated alkaline aqueous solution from the cathode-side liquid chamber and supplies the untreated alkaline aqueous solution to the cathode-side liquid chamber.

6. The biological iron material manufacturing apparatus according to claim 1 or 3, further comprising a solid material discharge section for discharging the settled biological iron material from the anode side liquid chamber.

7. The biological iron material manufacturing apparatus according to claim 1 or 3, further comprising a liquid material discharge section for discharging the biological iron material dissolved in the alkaline aqueous solution from the anode-side liquid chamber.

8. The biological iron material manufacturing apparatus according to claim 7, wherein the anode side liquid chamber is provided with an alkaline aqueous solution supply unit for supplying the untreated alkaline aqueous solution in addition to the liquid material discharge unit.

9. The biological iron material manufacturing apparatus according to claim 1 or 3, further comprising a control device that generates and supplies control signals to control the operation of each component of the biological iron material manufacturing apparatus.

10. The process involves using an anode that contains iron and does not contain any metal with a higher ionization tendency than iron, and a cathode that does not dissolve or dissolve when energized, and passing an electric current through an alkaline aqueous solution containing at least one of fulvic acid, humic acid, and a high-molecular-weight organic acid extracted from biomass. The aforementioned alkaline aqueous solution is stored in a container divided into two liquid chambers via a cation exchange member. The anode is placed in one liquid chamber, and the cathode is placed in the other liquid chamber. The aforementioned alkaline aqueous solution is obtained by extracting the polymeric organic acid from biomass. A method for producing iron materials for biological use, wherein in the step of applying electricity, electricity is applied until the pH and salt concentration of the alkaline aqueous solution in the liquid chamber where the anode is installed reach predetermined target values.

11. A method for producing a biological iron material according to claim 10, wherein air is supplied to the liquid chamber in which the anode is located.

12. A method for producing a biological iron material according to claim 10 or 11, comprising discharging the treated alkaline aqueous solution from the liquid chamber in which the cathode is located, and supplying the untreated alkaline aqueous solution to the liquid chamber in which the cathode is located.

13. A method for producing a biological iron material according to claim 10 or 11, wherein the precipitated biological iron material is discharged from the liquid chamber in which the anode is located.

14. A method for producing a biological iron material according to claim 10 or 11, wherein the biological iron material dissolved in the alkaline aqueous solution is discharged from the liquid chamber in which the anode is located.

15. A method for producing a biological iron material according to claim 10 or 11, comprising discharging the biological iron material dissolved in the alkaline aqueous solution from the liquid chamber in which the anode is located, in addition to supplying the untreated alkaline aqueous solution.

16. An aqueous solution containing iron chelated with fulvic acid or a biomass-extracted high-molecular-weight organic acid soluble in water under neutral and acidic conditions, The pH is between 4 and 10. The electrical conductivity is 100 μS / cm or less. Iron materials for biological applications.

17. A solid containing iron chelated with humic acid or a biomass-extracted high-molecular-weight organic acid that is insoluble in water under neutral and acidic conditions. Iron materials for biological applications.

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