Water quality improvement member, water quality improvement method, and shellfish growth method

Abstract

To provide a water quality improvement member capable of easily and stably supplying iron ions and improving the quality of iron-deficient environmental water, a water quality improvement method capable of improving the quality of environmental water, and a shellfish growth method using water quality improvement member.SOLUTION: A laminated member 1, which is submerged in environmental water O to improve the quality of the environmental water O, has a water quality improvement body 10 configured in the form of a plate. The water quality improvement body 10 includes a graphite-structured carbon material 40 having a hexagonal mesh laminate structure, and an iron material 30 adhered to the carbon material 40, with a first protruding piece 32 and a second protruding piece 33 that adhere and bond the iron material 30 and the carbon material 40.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a water quality improving member for improving the quality of environmental water such as seawater, a water quality improving method, and a shellfish production method. [Background technology]

[0002] In recent years, coastal barrenness, the decline of seaweed beds such as kelp in coastal waters, has become a problem. Various causes of coastal barrenness have been cited, including rising sea temperatures and seawater pollution, but one of the causes has also been pointed out to be a lack of iron, which is necessary for the absorption of nutrients and photosynthesis.

[0003] As a method for improving the quality of such seawater that is deficient in iron by supplying iron to the seawater, for example, Patent Document 1 discloses a method in which a fishing reef having a layer of easily soluble iron is dropped into the sea to supply iron to the seawater. In more detail, it is said that by pouring molten slag made by heating and melting waste into a hydrous iron-containing material that is made by mixing red mud, which contains a lot of iron, and pulse sludge, which is a hydrous material, and then heating and molding it, an iron layer that allows the iron contained in the hydrous iron-containing material to easily dissolve and ionize can be formed on the surface of the molten slag. Molten slag with such an iron layer can be thrown into the sea as a fishing reef, and it is said that it can supply iron to seawater as iron ions and improve the water quality of seawater that is lacking in iron.

[0004] However, the method disclosed in Patent Document 1 required a lot of effort to produce the fishing reef, and the amount of iron layer adhering to the molten slag varied depending on the amount of iron contained in the original red mud, so that iron ions could not be supplied stably and the water quality could not be sufficiently improved. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2005-021014 A Summary of the Invention [Problem to be solved by the invention]

[0006] The object of the present invention is to provide a water quality improvement component that can easily and stably supply iron ions and improve the water quality of environmental water that is deficient in iron, a water quality improvement method that can improve the water quality of environmental water, and a method for growing shellfish using the water quality improvement component. [Means for solving the problem]

[0007] The present invention is a water quality improvement component that is immersed in environmental water to improve the water quality of the environmental water, and is characterized in that it has a plate-shaped component body that is composed of a carbon material with a graphite structure having a hexagonal mesh-like laminated structure and an iron material adhered to the carbon material, and a water-resistant adhesive layer is provided at least in part between the carbon material and the iron material.

[0008] The present invention also relates to a water quality improvement component that is immersed in environmental water to improve the water quality of the environmental water, the component body having a plate-like structure, the component body being composed of a carbon material with a graphite structure having a hexagonal mesh-like laminated structure and an iron material in close contact with the carbon material, and a joint is provided to join the iron material and the carbon material in close contact with each other. Furthermore, the present invention is characterized in being a water quality improving method for improving the quality of the environmental water by immersing the above-mentioned water quality improving member in the environmental water and dissolving the iron material in the environmental water.

[0009] The environmental water includes water from public and private water bodies such as the sea, rivers, and lakes, as well as groundwater. The graphite structure having the above-mentioned hexagonal mesh-like laminated structure is a structure based on graphite that has free electrons and is conductive, and includes, for example, powder, particle, nodule, or plate-like graphite, carbon graphite sheets, and mixtures of graphite with other materials.

[0010] The member body includes a structure in which powder, particle, lump or plate-like iron material is adhered to a plate-like carbon material, and a structure in which powder, particle, lump or lump-like iron material is adhered to a carbon material. Here, "close contact" refers not only to a state in which the carbon material and the iron material are in contact with each other without any gaps, but also to a state in which there is a partial gap between the carbon material and the iron material.

[0011] The joint refers to a structure that can physically or mechanically adhere the iron material to the carbon material, and includes, for example, an engagement structure in which an engagement piece provided on at least one of the iron material and the carbon material engages with an engagement portion provided on the other material, and a structure in which a protrusion provided on one material is pressed into an insertion hole provided on the other material to join them.

[0012] The iron material and the carbon material may be in a bonded state so long as they can ensure electrical conductivity between the iron material and the carbon material. For example, this includes a case where the adhesive layer is provided in a portion between the iron material and the carbon material, and the iron material and the carbon material are in contact with each other in a portion where the adhesive layer is not provided, and a case where the adhesive layer having electrical conductivity is provided over the entire area between the iron material and the carbon material.

[0013] According to this invention, since the carbon material having a graphite structure with a hexagonal mesh-like laminated structure is conductive, by immersing the member body in which the carbon material and the iron material are bonded together by a water-resistant adhesive layer or joint in environmental water, a potential difference is generated at the contact portion between the carbon material and the iron material, and iron ions can be easily and stably eluted into the environmental water. Therefore, iron ions can be easily and stably supplied to the environmental water, and the water quality of environmental water lacking iron can be improved. In addition, since the amount of iron material bonded to the carbon material can be easily adjusted, the amount of iron ions eluted into the environmental water and the elution period can be easily and stably adjusted.

[0014] In this way, the water quality improving member, which is a structure in which a carbon material with a graphite structure having a hexagonal mesh-like laminated structure and an iron material are bonded together by a water-resistant adhesive layer or joint, can easily and stably increase the amount of iron ions in environmental water and easily adjust the amount of iron ions eluted into the environmental water. Therefore, the water quality of the environmental water can be easily and stably improved, and phytoplankton can be propagated in the environmental water, or the growth of shellfish, seaweed, etc. can be promoted.

[0015] As an aspect of the present invention, the carbon material and the iron material may be formed in a planar shape, and the iron material may be sandwiched between the carbon materials from both main surfaces. According to this invention, iron ions are eluted from the ends of the iron material sandwiched between the planar carbon materials so as to dissolve toward the center. That is, the iron material is immersed in environmental water while being sandwiched between the carbon materials and in close contact with them, so that iron ions can be eluted stably over a long period of time. Therefore, water quality can be improved stably over a long period of time.

[0016] As another aspect of the present invention, the thickness of the iron material may be greater than 0.1 mm and smaller than 0.3 mm. According to the present invention, iron ions can be eluted efficiently over a long period of time.

[0017] More specifically, when the thickness of the iron material is 0.1 mm or less, the iron material dissolves in a short period of time when submerged in environmental water, and therefore sufficient iron ions cannot be dissolved over the period required for the growth of, for example, phytoplankton, or shellfish and seaweed. On the other hand, when the thickness of the iron material is 0.3 mm or more, the iron material in the central part in the thickness direction may peel off from the carbon material during the process of dissolving the iron ions from the contact area with the iron material, and there is a risk that the iron ions cannot be efficiently dissolved.

[0018] In contrast, by making the thickness of the planar iron material sandwiched between the carbon materials greater than 0.1 mm and smaller than 0.3 mm, the iron material can maintain its adhesion to the carbon material even if it dissolves when submerged in environmental water, and iron ions can be stably eluted for a period required for the growth of phytoplankton, shellfish, seaweed, etc. Therefore, the environment of the environmental water can be stably improved for a period sufficient for the growth of phytoplankton, shellfish, seaweed, etc.

[0019] In another aspect of the present invention, a plurality of the component bodies may be stacked in the plate thickness direction, a stacking section may be provided for maintaining the stacked state, and at least one of the stacked component bodies may be bent in the plate thickness direction. The laminated portion may be a rod-shaped or string-shaped body that penetrates and connects the multiple component bodies stacked in the plate thickness direction, or may be configured as a frame that supports a portion of the multiple component bodies stacked in the plate thickness direction.

[0020] According to this invention, among the multiple component bodies stacked in the thickness direction, a gap can be formed between the component body bent in the thickness direction and the other component bodies. As a result, when the component body is immersed in environmental water, the environmental water flows through the formed gap, and iron ions can be efficiently eluted from the bent component body, the adjacent component bodies, and the bent component body. Therefore, the water quality of the environmental water can be more efficiently improved.

[0021] In another aspect of the present invention, a stacking section is provided for stacking a plurality of the component bodies in the plate thickness direction and maintaining the stacked state, and spacing sections are provided between the stacked component bodies to separate the component bodies at a predetermined interval. The separating portion may be provided on some or all of the stacked member bodies so as to separate the member bodies from each other at a predetermined interval and form a gap between the member bodies through which environmental water can flow.

[0022] According to this invention, gaps can be formed between the multiple member bodies stacked in the plate thickness direction, so that environmental water can flow through the formed gaps when the member bodies are submerged in environmental water. Therefore, iron ions can be efficiently eluted from the member bodies separated by the separation portions, and the water quality of the environmental water can be more efficiently improved.

[0023] As a further aspect of the present invention, the laminated portion may be made of a biodegradable material. According to the present invention, the iron ions are eluted, so that the carbon material and the laminated portion remaining in the environmental water can be naturally decomposed in the environmental water. Therefore, there is no need to recover the carbon material and the laminated portion, which improves workability and prevents the laminated portion from deteriorating the water quality of the environmental water.

[0024] In another aspect of the present invention, the component body may be housed inside a container through which the environmental water flows when the component body is submerged in the environmental water, and a plurality of the component bodies may be housed in the container, with at least one of the component bodies being bent in the thickness direction.

[0025] The container may be of any shape as long as it is capable of containing the main body of the component and is configured to allow the environmental water to flow through it when submerged in the environmental water, and may be a cylindrical bag with an opening through which the environmental water can flow from one side of the container to the other, or a mesh bag or box-shaped body configured to allow the environmental water to flow from multiple directions.

[0026] According to this invention, a gap can be formed between the member main body bent in the thickness direction and the other member main bodies housed inside the housing. This allows the environmental water flowing through the housing in a state where it is submerged in environmental water to flow through the gap formed between the bent member main body and the other member main bodies. Therefore, iron ions can be efficiently eluted from the bent member main body, the stacked member main bodies, and the bent member main body, and the water quality of the environmental water can be more efficiently improved.

[0027] As a further aspect of the present invention, the container may be configured in a mesh shape. According to the present invention, the environmental water can be circulated around the bent member body more reliably, so that the iron ions eluted from the iron material can be carried by the environmental water and dispersed around. Therefore, the water quality improvement member configured in this way can improve the water quality more efficiently.

[0028] As a further aspect of the present invention, the container may be made of a biodegradable material. According to the present invention, the iron ions are eluted, so that the carbon material and the laminated portion remaining in the environmental water can be naturally decomposed in the environmental water. Therefore, there is no need to recover the carbon material and the laminated portion, which improves workability and prevents the container from deteriorating the water quality of the environmental water.

[0029] The present invention is also characterized in that it is a method for growing shellfish by immersing the above-mentioned water quality improvement member in the environmental water and growing shellfish on the carbon material constituting the water quality improvement member. According to the present invention, the amount of iron ions in environmental water can be easily and stably increased and the amount of iron ions eluted into the environmental water can be easily adjusted by simply bonding a carbon material having a graphite structure with a hexagonal mesh-like laminated structure and an iron material with a water-resistant adhesive layer or joint. Therefore, for example, around shellfish such as oysters, iron ions that serve as nutrients for phytoplankton can be easily and stably dispersed in the environmental water, thereby allowing the proliferation of phytoplankton necessary for the growth of the shellfish.

[0030] In addition, the iron material is sandwiched between the carbon material, which not only creates a potential difference between the iron material and the carbon material but also allows the oysters to easily attach eggs. This allows iron ions to be eluted around the oysters that have attached eggs to the carbon material, which allows phytoplankton to grow around the oysters. This further promotes the growth of the oysters by feeding on the grown phytoplankton. Effect of the Invention

[0031] The present invention makes it possible to provide a water quality improvement component that can easily and stably supply iron ions and improve the water quality of environmental water that is deficient in iron, a water quality improvement method that can improve the water quality of environmental water, and a shellfish cultivation method using the water quality improvement component. [Brief description of the drawings]

[0032] [Figure 1] Schematic diagram of a method for improving water quality using laminated materials. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] An explanatory diagram of iron materials. [Diagram 5] An explanatory diagram of a water quality improvement body. [Figure 6] Graph of iron ion elution versus immersion time. [Figure 7] Graph of phytoplankton counts for laminated members. [Figure 8] A photo showing the growth status of oysters. [Figure 9] FIG. 11 is an explanatory view of a laminated member according to another embodiment. [Figure 10] FIG. 11 is a schematic front view of a laminated member according to another embodiment. [Figure 11] FIG. 11 is a schematic perspective view of a laminated member according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] An embodiment of the present invention will now be described with reference to the drawings. Fig. 1 shows a schematic diagram of a method for improving the water quality of environmental water O such as seawater using a laminated member 1. Fig. 2 shows a schematic perspective view of the laminated member 1, and Fig. 3 shows an enlarged schematic side view of the water quality improver 10. Fig. 4 shows an explanatory diagram of the iron material 30, and Fig. 5 shows schematic cross-sectional views of the water quality improver 10 and the water quality improver 10a. Fig. 6 shows a graph of the elution of iron ions versus the immersion time, and Fig. 7 shows a graph showing the number of plankton with and without the laminated member 1. Fig. 8 shows a photograph of oysters K grown in the water quality improver 10. Figs. 9 to 11 show explanatory diagrams of other embodiments of the laminated member 1.

[0034] As shown in Figures 1 and 2, the laminated member 1 is composed of a plurality of water quality improvement bodies 10 and connecting members 20 that connect the plurality of water quality improvement bodies 10 so that they are stacked, and is used by immersing it in environmental water O, such as seawater.

[0035] 2, the water quality improvement body 10 is a flat plate having a disk shape in plan view with a through hole 11 passing through the center in the plan view along the plate thickness direction. The through hole 11 passing through the center of the water quality improvement body 10 in plan view is configured so that a connecting member 20 can be inserted therethrough.

[0036] A detailed description will be given of the water quality improver 10. As shown in Fig. 3, the water quality improver 10 is composed of an iron material 30, which is a flat iron plate, and a pair of carbon materials 40 sandwiched between the iron material 30 on both main surfaces. As shown in Figure 4(a), the iron material 30 is a flat plate having an iron material through hole 31 with a predetermined inner diameter penetrating the central portion when viewed from above, and a first protruding piece 32 protruding toward one side of the main surface and a second protruding piece 33 protruding toward the other side of the main surface are provided at equal intervals around the iron material through hole 31.

[0037] In this embodiment, a zinc-plated steel plate (Silver Top TE-90: Toyo Kohan Co., Ltd.) is used as the iron material 30, but the iron material 30 is not limited to this. For example, in consideration of the impact on health hazards, it is preferable that the iron material 30 does not contain heavy metals, etc.

[0038] In this embodiment, the thickness of the iron material 30, which is a flat plate having a substantially circular shape in a plan view, is 0.2 mm. However, the thickness of the iron material 30 may be greater than 0.1 mm and less than 0.3 mm, and is not limited to this thickness.

[0039] As shown in FIG. 4(b), the first protruding piece 32 is a cylindrical protruding piece formed by processing the iron material 30 so as to protrude from the other side of the main surface to one side, and the tip is slightly curved radially outward. The second protruding piece 33 has a configuration similar to that of the first protruding piece 32, except that it protrudes toward the other side of the main surface, and therefore a description thereof will be omitted.

[0040] The first protruding pieces 32 and the second protruding pieces 33 thus configured are alternately provided at a predetermined interval on the surface of the iron material 30. That is, the first protruding pieces 32 and the second protruding pieces 33 protrude evenly toward both main surfaces of the iron material 30.

[0041] The carbon material 40 is a so-called carbon graphite sheet having a graphite structure with a hexagonal mesh-like laminated structure. That is, the carbon material 40 has a structure based on conductive graphite having free electrons inside. In addition, a carbon through hole 41 having the same diameter as the iron material through hole 31 is provided in the approximate center of the carbon material 40 in a plan view.

[0042] In this embodiment, the thickness of the carbon material 40 is 0.5 mm, but may be changed appropriately according to the thickness of the iron material 30. For example, when the thickness of the iron material 30 is 0.1 to 0.15 mm, the thickness of the carbon material 40 may be 0.4 mm, and when the thickness of the iron material 30 is 0.25 to 0.3 mm, the thickness of the carbon material 40 may be 0.6 mm.

[0043] The carbon material 40 configured in this manner is placed against both main surfaces of the iron material 30 and pressed against the iron material 30, whereby the main surfaces of the carbon material 40 are closely adhered to both main surfaces of the iron material 30 and the first protruding piece 32 and the second protruding piece 33 can be embedded into the surface of the carbon material 40.

[0044] This allows the iron material 30 and the carbon material 40 to be physically bonded together, thereby producing a water quality improver 10 in which the iron material 30 and the carbon material 40 are tightly adhered and integrated together (see FIG. 5(a)). By physically bonding the iron material 30 and the carbon material 40 in this manner, electrical conductivity between the iron material 30 and the carbon material 40 can be ensured.

[0045] In the above-mentioned water quality improver 10, the main surfaces of the iron material 30 and the carbon material 40 are in close contact with each other without any gaps. In this way, in the water quality improver 10, it is preferable that the entire surfaces of the iron material 30 and the carbon material 40 are in contact with each other without any gaps, but this is not limited, and for example, only a portion may be in contact with each other without any gaps. In other words, it is preferable that the iron material 30 and the carbon material 40 are in sufficient contact with each other so that conductivity can be ensured between the iron material 30 and the carbon material 40 for a long period of time.

[0046] In the above-mentioned water quality improver 10, the iron material 30 and the carbon material 40 are physically bonded together by having the first protruding piece 32 and the second protruding piece 33 protruding from the main surface of the iron material 30 bite into the carbon material 40, but the invention is not limited to this configuration. For example, as shown in FIG. 5(b), the main surfaces of the iron material 30 and the carbon material 40 may be chemically bonded together via a water-resistant and conductive adhesive. By chemically bonding the main surfaces of the iron material 30 and the carbon material 40 together with an adhesive, a water quality improver 10a in which the iron material 30 and the carbon material 40 are integrated can be manufactured. In addition, the water quality improver 10a in which the iron material 30 and the carbon material 40 are bonded together via the adhesive layer 50 can ensure electrical conductivity between the iron material 30 and the carbon material 40.

[0047] Here, the iron material 30 and the carbon material 40 are adhered to each other via the adhesive layer 50 having electrical conductivity, but the adhesive layer 50 does not necessarily have to be electrically conductive. For example, the iron material 30 and the carbon material 40 may be adhered to each other via the adhesive layer 50 having no electrical conductivity so that parts of the iron material 30 and the carbon material 40 are in direct contact with each other.

[0048] The connecting member 20 is a string-like body having a thickness that allows it to be inserted into the through-hole 11, and is made of a biodegradable material. One end of such a long connecting member 20 is provided with a floating part 21, which has a specific gravity lighter than water. In addition, a knotted part 22 that can be engaged with the through-hole 11 is provided in the center of the connecting member 20 (see FIG. 2).

[0049] Next, a method for manufacturing the laminated member 1 in which the connecting member 20 is inserted into the water quality improver 10 will be described. First, at a position spaced a predetermined distance from the floating portion 21, the other end of the connecting member 20 is inserted into the through hole 11, and the connecting member 20 is tied at the other end of the water quality improver 10 to form the knotted portion 22. This allows the water quality improver 10 to be locked to the knotted portion 22, and movement of the water quality improver 10 to the other end of the connecting member 20 can be restricted.

[0050] Similarly, at a position spaced a predetermined distance from the water quality improvement body 10 engaged with the connecting member 20, the other end of the connecting member 20 is inserted into the through hole 11, and the connecting member 20 is knotted at the other end of the water quality improvement body 10 to form a knotted portion 22. By repeating this process, a laminated member 1 can be manufactured in which a plurality of water quality improvement bodies 10 are stacked at predetermined intervals along the longitudinal direction of the connecting member 20.

[0051] The laminated member 1 configured in this manner can easily and stably supply iron ions to the environmental water O, such as seawater, which is deficient in iron, by immersing the water quality improvement body 10 in the environmental water O, thereby improving the water quality of the environmental water O which is deficient in iron. Specifically, by placing the laminated member 1 in the environmental water O, the floating portion 21 floats on the water surface, and the multiple water quality improvers 10 are arranged in parallel at a predetermined interval in the vertical direction. That is, the balling portion 22 exerts a function of maintaining the intervals between the laminated water quality improvers 10 when the water quality improvers 10 are submerged in water.

[0052] By arranging the water quality improvers 10 at a predetermined interval in this manner, the environmental water O flows between the adjacent water quality improvers 10. That is, the environmental water O comes into contact with the main surface of the carbon material 40 that sandwiches and adheres closely to the main surface of the iron material 30.

[0053] Here, since the iron material 30 is in close contact with the carbon material 40, a potential difference is generated between the iron material 30 and the carbon material 40. Therefore, divalent iron ions are easily dissolved into the environmental water O from the end face of the iron material 30 that is in close contact with the carbon material 40, more specifically, from the side surface of the iron material 30 (see FIG. 6).

[0054] Here, when the thickness of the iron material 30 is 0.1 mm or less, the iron material 30 dissolves in a short period of time when immersed in the environmental water O, and therefore sufficient iron ions cannot be eluted over a long period of time. On the other hand, when the thickness of the iron material 30 is 0.3 mm or more, the iron material 30 in the central portion in the thickness direction peels off from the carbon material 40 during the process of elution of iron ions from the contact portion with the iron material 30, and therefore the iron ions cannot be eluted efficiently.

[0055] In contrast, by setting the thickness of the planar iron material 30 sandwiched between the carbon materials 40 to 0.2 mm, which is greater than 0.1 mm and smaller than 0.3 mm, the iron material 30 can maintain its adhesion to the carbon material 40 even if the iron material 30 dissolves when immersed in environmental water O.

[0056] As described above, iron ions are eluted from the iron material 30, so that iron ions can be supplied to the environmental water O that is deficient in iron ions. This allows phytoplankton in the environmental water O to grow.

[0057] In fact, experiments were conducted in Lake Hamana (hereinafter referred to as Lake A) and Kesennuma (hereinafter referred to as Sea B), where fresh water and seawater mix, on the dissolution of iron when a 0.2 mm thick iron material 30 and a water quality improvement body 10 consisting of a 0.2 mm thick iron material 30 sandwiched between carbon material 40 were submerged in water.

[0058] More specifically, a laminated member 1 having a water quality improver 10 in which 0.2 mm iron material 30 is sandwiched between carbon materials 40, and 0.2 mm iron material 30 connected with connecting members 20 were submerged in lake A and ocean B, respectively, and the masses of the iron material 30 and the iron plate were measured for a specified month. Then, the reduction rates of the masses of the iron material 30 and the iron plate relative to the submersion period (months) in which the laminated member 1 and the iron plate were submerged were calculated (see FIG. 6).

[0059] As a result of this experiment, when the iron plate was submerged, the mass of the iron plate increased slightly in both Lake A and Ocean B. On the other hand, the mass of the iron material 30 used in the laminated member 1 decreased significantly in both Lake A and Ocean B, and the decrease was stable for a long period of time.

[0060] In detail, when the laminated member 1 is submerged in water for one month, the mass of the iron material 30 is reduced by approximately 5% in both Lake A and Ocean B. When the laminated member 1 is submerged in water for two months, the mass of the iron material 30 is reduced by just over 10% in Lake A and by just under 10% in Ocean B.

[0061] The results of the above experiments clearly show that in Lake Hamana and Kesennuma, a larger amount of iron ions are eluted from the iron material 30 sandwiched between the carbon materials 40 than when only the iron material 30 is submerged in water. In other words, more iron ions can be eluted from the iron material 30 when the iron material 30 is sandwiched between the carbon materials 40 than when only the iron material 30 is submerged in water.

[0062] Moreover, since at least the weight of the laminated member 1 is significantly reduced and is steadily reduced over a long period of time, it is clear that a sufficient amount of iron ions is eluted from the iron material 30 sandwiched between the carbon materials 40. Therefore, it is suggested that the water quality improver 10 in which the iron material 30 is sandwiched between the carbon materials 40 can have a sufficient amount of iron ions eluted therefrom by immersing it in environmental water O, thereby improving the water quality of the environmental water O.

[0063] In addition, a comparison was made between the case where the laminated member 1 was not submerged in Lake Hamana and the case where the laminated member 1 was submerged in Lake Hamana. More specifically, the laminated member 1 was submerged in a specified location (point C) in Lake Hamana for three months, and then 1 L of brackish water was collected as a sample. On the same day, 1 L of brackish water was also collected as a sample at a location (point D) approximately 10 m away from point C. The number of phytoplankton in the samples collected at points C and D was measured.

[0064] Measuring phytoplankton is a common method. In simple terms, the collected sample is left to stand for at least one day, the supernatant is removed, the sample is concentrated, and then left to stand for at least one day again. Next, the concentrated sample is stirred evenly, and 1 ml is dispensed onto a plankton counting plate and counted under an optical microscope. The number of plankton counted is then multiplied by 1000 to obtain the number of plankton contained in the sample.

[0065] At point D where the laminated member 1 was not submerged, the number of phytoplankton was approximately 7 M / L, as shown in Figure 7, whereas at point C where the laminated member 1 was submerged, the number of phytoplankton was approximately 11 M / L. In other words, when the water quality improving body 10 was submerged, the number of phytoplankton increased by approximately 1.5 times compared to when the water quality improving body 10 was not submerged.

[0066] As such, since there is a significant difference in the number of phytoplankton between the nearby point C where the water quality improvement body 10 was submerged, and point D where the water quality improvement body 10 was not submerged, it is suggested that submerging the water quality improvement body 10 causes phytoplankton to proliferate in the area around the submerged water quality improvement body 10.

[0067] As described above, the laminated member 1 configured in this manner can be immersed in environmental water O to allow iron ions to elute from the iron material 30 constituting the water quality improver 10. This allows iron ions, which are nutrients for phytoplankton, to be easily and stably dispersed in the environmental water O, allowing the phytoplankton necessary for shellfish growth to proliferate. In addition, the carbon material 40 sandwiching the iron material 30 is a material on which young shellfish such as oysters K are likely to lay eggs.

[0068] For example, a laminated member 1 using the carbon material 40 on which oyster K juveniles are attached is submerged in environmental water O for a predetermined period of time. This allows phytoplankton to grow around the shellfish such as oysters K that have attached eggs to the carbon material 40, and the oysters K grow by feeding on the proliferated phytoplankton (see FIG. 8).

[0069] In this way, by using the carbon material 40 on which the oyster K juveniles can easily attach eggs to sandwich the iron material 30, iron ions can be eluted around the oyster K juveniles that have attached eggs to the carbon material 40, and phytoplankton can be multiplied around the oyster K juveniles. Therefore, the oysters K can grow efficiently by feeding on the multiplied phytoplankton.

[0070] In the above embodiment, the laminated member 1 is provided with the beaded portion 22 so that the water quality improvers 10 are stacked at a predetermined interval, but this configuration is not necessarily required. For example, as shown in FIG. 9(a), instead of providing the beaded portion 22 on the connecting member 20, a separate member, an insulating material 60, may be provided between adjacent water quality improvers 10. This allows the connecting member 20 to maintain the stacked state of the water quality improvers 10 and to maintain the interval between the water quality improvers 10. In this way, the laminated member 1b, which maintains the interval between the water quality improvers 10 via the insulating material 60, can achieve the same effect as the laminated member 1 by immersing it in environmental water O. Similarly to the connecting members 20, the spacing members 60 are made of a biodegradable material.

[0071] 9(b), for example, instead of providing the connecting member 20 with the beaded portion 22, the water quality improver 10 may be curved to provide a gap between adjacent water quality improver bodies 10. This allows the connecting member 20 to maintain the stacked state of the water quality improver bodies 10, and also allows gaps to be formed between the water quality improver bodies 10 so that the environmental water O can flow. A stacked member 1c formed by inserting the connecting member 20 into the curved water quality improver bodies 10 in this way can achieve the same effect as the stacked member 1 by immersing it in the environmental water O.

[0072] Furthermore, in the laminated member 1, multiple water quality improvement bodies 10 are laminated by inserting a string-like connecting member 20 into the through holes 11 provided in the multiple water quality improvement bodies 10, but this shape is not necessarily required, and for example, as shown in Figure 10, a frame-shaped connecting member 20 may hold some of the multiple water quality improvement bodies 10.

[0073] More specifically, the connecting member 20d is composed of a plurality of support columns 24 arranged along the circumferential direction of the water quality improver 10. The support columns 24 are each formed of a columnar body, and a plurality of clamping portions 25 capable of clamping the water quality improver 10 facing inward in the circumferential direction are provided at predetermined intervals in the height direction.

[0074] By clamping the water quality improver 10 between the multiple clamping parts 25 provided in the height direction in this manner, it is possible to manufacture a laminated member 1d in which the laminated water quality improver 10 are held at intervals. By immersing this laminated member 1d in environmental water O, the environmental water O can flow between the water quality improver 10, thereby achieving the same effect as the laminated member 1.

[0075] In the laminated members 1, 1b, and 1c, a plurality of water quality improvers 10 are laminated by inserting a string-like connecting member 20 into through holes 11 provided in the plurality of water quality improvers 10, but it is not necessary to laminate the water quality improvers 10. For example, as shown in FIG. 11, a plurality of water quality improvers 10 may be housed in a box-shaped container 70 formed in a mesh pattern. At least one of the water quality improvers 10 is bent in the plate thickness direction. The container 70 is made of a biodegradable material.

[0076] In this way, the laminated member 1e, in which a plurality of water quality improvers 10 are accommodated in the accommodation body 70, can achieve the same effect as the laminated member 1 by immersing it in environmental water O, whereby the environmental water O that has passed through the accommodation body 70 configured in a mesh shape flows between the water quality improvers 10. In addition, because the accommodation body 70 is configured in a mesh shape, iron ions eluted from the iron material 30 can be placed on the environmental water O and dispersed around.

[0077] Here, the container 70 has a mesh shape configured to allow the environmental water O to flow from multiple directions, but may have any shape as long as it is capable of containing the water quality improving body 10 therein and is configured to allow the environmental water O to flow inside when submerged in the environmental water O. For example, the container 70 may be a cylindrical bag having an opening through which the environmental water O can flow from one side to the other.

[0078] In this way, the laminated members 1, 1a, 1b, 1c, 1d, 1e that are immersed in environmental water O such as seawater to improve the water quality of the environmental water O have a water quality improver 10 configured in a plate shape. The water quality improver 10 is composed of a carbon material 40 with a graphite structure having a hexagonal mesh-like laminated structure, and an iron material 30 in close contact with the carbon material 40, and is provided with a first protruding piece 32 and a second protruding piece 33 that join the iron material 30 and the carbon material 40 in close contact with each other.

[0079] Furthermore, in the laminated members 1, 1a, 1b, 1c, 1d, and 1e, the laminated member 1a that is immersed in the environmental water O to improve the water quality of the environmental water O may have a water quality improver 10a configured in a plate shape, instead of the water quality improver 10. The water quality improver 10a is composed of a carbon material 40 having a graphite structure with a hexagonal mesh-like laminated structure and an iron material 30 adhered to the carbon material 40, and a water-resistant adhesive layer 50 is provided at least partially between the carbon material 40 and the iron material 30. A water quality improvement method using such laminated members 1, 1a, 1b, 1c, 1d, and 1e is a method in which the laminated members 1, 1a, 1b, 1c, 1d, and 1e are immersed in environmental water O, and the iron material 30 is dissolved in the environmental water O, thereby improving the water quality of the environmental water O.

[0080] In the water quality improver 10, 10a, the carbon material 40 having a graphite structure with a hexagonal mesh-like laminated structure is conductive, so that by immersing the water quality improver 10, 10a in which the carbon material 40 and the iron material 30 are adhered to each other by the water-resistant adhesive layer 50 or the first protruding piece 32 and the second protruding piece 33 in the environmental water O, iron ions can be easily and stably eluted into the environmental water O. Therefore, iron ions can be easily and stably supplied, and the water quality of the environmental water O in which iron is deficient can be improved. In addition, since the amount of the iron material 30 adhered to the carbon material 40 can be easily adjusted, the total amount of iron ions eluted into the environmental water O can be easily and stably eluted.

[0081] In this way, the amount of iron ions in the environmental water O can be easily and stably increased and the amount of iron ions eluted into the environmental water O can be easily adjusted by simply bonding the carbon material 40 having a graphite structure with a hexagonal mesh-like laminated structure and the iron material 30 with the water-resistant adhesive layer 50 or the first protruding piece 32 and the second protruding piece 33. Therefore, the water quality of the environmental water O can be easily and stably improved, and phytoplankton can be propagated in the environmental water O, or the growth of shellfish, seaweed, and the like can be promoted.

[0082] Furthermore, since the main surfaces of the carbon material 40 and the iron material 30 are in close contact with each other, even if the volume of the iron material 30 decreases due to being immersed in environmental water O for a long period of time, iron ions can be eluted stably over the long term.

[0083] Moreover, the carbon material 40 and the iron material 30 are configured in a planar shape, and the iron material 30 is sandwiched between the carbon materials 40 from both of its main surfaces. This allows iron ions to be eluted so as to dissolve from the ends of the iron material 30 sandwiched between the planar carbon materials 40 toward the center. That is, the iron material 30 is immersed in the environmental water O while being sandwiched between the carbon materials 40 and in close contact with the carbon materials 40, and therefore iron ions can be eluted stably over the long term. This allows the water quality to be improved stably over the long term.

[0084] Furthermore, the plate thickness of the iron material 30 is set to 0.2 mm, which is greater than 0.1 mm and smaller than 0.3 mm, thereby enabling iron ions to be eluted efficiently over a long period of time.

[0085] More specifically, when the thickness of the iron material 30 is 0.1 mm or less, the iron material 30 dissolves in a short period of time when submerged in environmental water O, and therefore sufficient iron ions cannot be dissolved over the period required for the growth of, for example, phytoplankton, shellfish, seaweed, etc. On the other hand, when the thickness of the iron material 30 is 0.3 mm or more, the iron material 30 in the central portion in the thickness direction peels off from the carbon material 40 during the process of dissolving the iron ions from the contact portion with the iron material 30, and therefore the iron ions cannot be efficiently dissolved.

[0086] In contrast, by setting the plate thickness of the planar iron material 30 sandwiched between the carbon materials 40 to 0.2 mm, which is greater than 0.1 mm and smaller than 0.3 mm, the iron material 30 can maintain a state of being in close contact with the carbon material 40 even if the iron material 30 dissolves when submerged in the environmental water O, and iron ions can be stably eluted for a period required for the growth of phytoplankton, shellfish, seaweed, etc. Therefore, the environment of the environmental water O can be stably improved for a period sufficient for the growth of phytoplankton, shellfish, seaweed, etc.

[0087] In addition, the connecting member 20 is made of a biodegradable material. Therefore, by dissolving the iron ions, the carbon material 40 and the connecting member 20 remaining in the environmental water O can be naturally decomposed in the environmental water O. Therefore, there is no need to perform an operation for recovering the carbon material 40 and the connecting member 20, which improves workability and prevents the connecting member 20 from deteriorating the water quality of the environmental water O.

[0088] In addition, in the laminated members 1, 1a, 1d, multiple water quality improvement bodies 10 are stacked in the plate thickness direction and have connecting members 20 that maintain the stacked state, and between the stacked water quality improvement bodies 10, there are provided balling sections 22 and clamping sections 25 that separate the water quality improvement bodies 10 at a predetermined interval.

[0089] Furthermore, in the laminated member 1b, multiple water quality improvement bodies 10 are stacked in the plate thickness direction and have connecting members 20 that maintain the stacked state, and between the stacked water quality improvement bodies 10, separating members 60 are provided to separate the water quality improvement bodies 10 at a predetermined interval.

[0090] This allows gaps to be formed between the multiple water quality improvers 10 stacked in the plate thickness direction, so that the environmental water O can flow through the formed gaps when the water quality improvers 10 are submerged in the environmental water O. Therefore, iron ions can be efficiently eluted from the water quality improvers 10 separated by the beading portions 22, and the water quality of the environmental water O can be more efficiently improved.

[0091] Similarly, in the laminated member 1c, a plurality of water quality improvers 10 are laminated in the plate thickness direction, a connecting member 20 is provided for maintaining the laminated state, and at least one of the laminated water quality improvers 10 is bent in the plate thickness direction. In this manner, among the plurality of water quality improvers 10 laminated in the plate thickness direction, a gap can be formed between the water quality improver 10 bent in the plate thickness direction and the other water quality improvers 10. As a result, when the laminated member 1c is immersed in environmental water O, the environmental water O flows through the formed gap, and iron ions can be efficiently eluted from the bent water quality improver 10, the adjacent water quality improver 10, and the bent water quality improver 10. Therefore, the water quality of the environmental water O can be improved more efficiently.

[0092] Furthermore, the laminated member 1e has a container 70 that can house the water quality improvement body 10 and through which the environmental water O flows when submerged in the environmental water O, and the container 70 houses a plurality of water quality improvement bodies 10, with at least one of the water quality improvement bodies 10 being bent in the thickness direction of the plate.

[0093] This allows a gap to be formed between the water quality improver 10 bent in the plate thickness direction and the other water quality improvers 10 housed inside the housing 70, so that when submerged in environmental water O, the environmental water O flowing through the housing 70 can flow through the gap formed between the bent water quality improver 10 and the other water quality improvers 10. Therefore, iron ions can be efficiently eluted from the bent water quality improver 10, the stacked water quality improver 10, and the bent water quality improver 10, and the water quality of the environmental water O can be improved more efficiently.

[0094] Furthermore, since the container 70 is configured in a mesh shape, the environmental water O flows more reliably around the bent water quality improver 10, so that the iron ions eluted from the iron material 30 can be carried by the environmental water O and dispersed around. Therefore, the water quality can be improved more efficiently.

[0095] Furthermore, since the container 70 is made of a biodegradable material, the iron ions are eluted, and the carbon material 40 and the connecting member 20 remaining in the environmental water O can be naturally decomposed in the environmental water O. Therefore, there is no need to perform an operation for recovering the carbon material 40 and the connecting member 20, improving workability and preventing the container 70 from deteriorating the water quality of the environmental water O.

[0096] As a method for growing shellfish using the laminated members 1, 1a, 1b, 1c, 1d, and 1e configured in this manner, the laminated members 1, 1a, 1b, 1c, 1d, and 1e are immersed in environmental water O, and shellfish such as oysters K can be grown on the carbon material 40 that constitutes the laminated members 1, 1a, 1b, 1c, 1d, and 1e.

[0097] As a result, the amount of iron ions in the environmental water O can be easily and stably increased and the amount of iron ions dissolved in the environmental water O can be easily adjusted with a structure in which the carbon material 40 having a graphite structure with a hexagonal mesh-like laminated structure and the iron material 30 are simply adhered to each other by the water-resistant adhesive layer 50 or the first protruding piece 32 and the second protruding piece 33. Therefore, the iron ions serving as nutrients can be easily and stably dispersed in the environmental water O around the oysters K, so that phytoplankton necessary for the growth of the oysters K can be multiplied. In addition, the juvenile oysters K stick to the depressions in the water quality improvement body 10 formed by the elution of the iron ions, and the growth of the oysters K can be promoted by feeding on the multiplied phytoplankton.

[0098] In the configuration of the present invention and the above-mentioned embodiment, the environmental water of the present invention corresponds to the environmental water O. The water quality improvement members correspond to the laminated members 1, 1a, 1b, 1c, 1d, and 1e. The member body corresponds to the water quality improvement body 10, 10a, The carbon material corresponds to carbon material 40, The iron material corresponds to iron material 30, The adhesive layer corresponds to adhesive layer 50, The joint portion corresponds to the first protruding piece 32 and the second protruding piece 33, The laminated portion corresponds to the connecting member 20, The spaced portion corresponds to the ball portion 22, The container corresponds to the container 70, but the present invention is not limited to the configuration of the above-mentioned embodiment, and many embodiments can be obtained.

[0099] For example, in this embodiment, the target water quality to be improved by the laminated member 1 is environmental water O such as seawater, but the environmental water O is not limited to seawater and may be water from public and private water bodies such as rivers and lakes, as well as groundwater.

[0100] In addition, the carbon material 40 is a carbon graphite sheet, but is not limited to a carbon graphite sheet as long as it has a structure based on graphite that has free electrons and is conductive. For example, it may be graphite in the form of powder, particle, nodule, or plate, or a mixture of graphite and other materials. [Explanation of symbols]

[0101] 1, 1a, 1b, 1c, 1d, 1e...Laminated members 10, 10a...Water quality improvement materials 20, 20d…Connecting member 23…Knotted part 30…Iron 32...First protruding piece 33...Second protruding piece 40…Carbon material 50...adhesive layer 70…Containment Unit

Claims

1. A water quality improving member that is immersed in environmental water to improve the water quality of the environmental water, A member body having a plate shape, The member body is The carbon material has a graphite structure having a hexagonal mesh-like laminated structure, and the iron material is bonded to the carbon material. A water-resistant adhesive layer is provided between at least a portion of the carbon material and the iron material. Water quality improvement materials.

2. A water quality improving member that is immersed in environmental water to improve the water quality of the environmental water, A member body having a plate shape, The member body is A carbon material having a graphite structure with a hexagonal mesh-like laminated structure; and an iron material adhered to the carbon material, A joint is provided to join the iron material and the carbon material in close contact with each other. Water quality improvement materials.

3. The carbon material and the iron material are configured in a planar shape, The iron material is sandwiched between the carbon materials on both main surfaces. The water quality improving member according to claim 1 or 2.

4. The thickness of the iron material is greater than 0.1 mm and smaller than 0.3 mm. The water quality improving member according to claim 3.

5. A laminated portion is provided for laminating a plurality of the member bodies in a plate thickness direction and maintaining the laminated state, At least one of the laminated member bodies is bent in the plate thickness direction. The water quality improving member according to claim 1 or 2.

6. A laminated portion is provided for laminating a plurality of the member bodies in a plate thickness direction and maintaining the laminated state, Between the stacked member bodies, a spacing portion is provided to space the member bodies at a predetermined distance. The water quality improving member according to claim 1 or 2.

7. The laminated portion is made of a biodegradable material. The water quality improving member according to claim 5.

8. a container capable of housing the member main body therein and through which the environmental water flows when the member is submerged in the environmental water; The housing contains a plurality of the member bodies, At least one of the member bodies is bent in the plate thickness direction. The water quality improving member according to claim 1 or 2.

9. The container is configured in a mesh shape. The water quality improving member according to claim 8.

10. The container is made of a biodegradable material. The water quality improving member according to claim 8.

11. The water quality improving member according to claim 1 or 2 is immersed in the environmental water, the iron material is dissolved in the environmental water, and the water quality of the environmental water is improved. How to improve water quality.

12. The water quality improving member according to claim 1 or 2 is immersed in the environmental water, The carbon material constituting the water quality improvement member is allowed to grow shellfish. How shellfish grow.

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