Marine life food generator

Abstract

To provide a feed generation device that filters and processes seawater pumped from a sewage discharge area where treated sewage is discharged, and feeds plankton and treated liquid obtained after filtration to shellfish and seaweed.SOLUTION: A feed generation system for marine organisms which utilizes seawater in a sea area where treated sewage treated in a water treatment facility is discharged for the growth of marine organisms, includes: a conveyance part 3 which draws seawater in the sewage discharge area and supplies it to a filtration device 2; the filtration device 2 which separates seawater into suspended matters and treated liquid; a feeding part 4A which feeds the treated liquid to seaweed in a seaweed culturing area; and a feeding part 4B that feeds the shellfish in a shellfish culturing area with the suspended matters that have been separated by cleaning liquid supplied from a cleaning liquid supply pipe 5 connected to the filtration device 2 together with the cleaning effluent. Therefore, the system can produce feed for multiple marine organisms with one device at the same time.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a feed producing device for marine organisms that produces feed for marine organisms such as shellfish and seaweed using a filtering device. [Background technology]

[0002] In the past, oligotrophy has occurred in marine areas where shellfish, seaweed, and other marine organisms live due to a lack of nutrients such as nitrogen and phosphorus. This oligotrophy has led to a decrease in plankton, causing problems such as the insufficient growth of oysters, which feed on plankton, and discoloration of seaweed, which grows by absorbing nutrients, causing problems for aquaculture.

[0003] Patent Document 1 discloses a technology that uses a filtration device with an alternating layer structure of filter media / culture medium layers and void layers as a feed concentration device, and describes that plankton attached to the filter media / culture medium layers is used as food for bivalve mollusks such as clams and mussels.

[0004] Patent Document 2 discloses a technology in which nitrogen and phosphorus components are dissolved from a fertilizer into water, suspended solids are filtered from the resulting eluate, and the filtered eluate is then supplied to seaweed such as Enteromorpha serrata and Sargassum species. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-171353 [Patent Document 2] Patent No. 6316579 Summary of the Invention [Problem to be solved by the invention]

[0006] Traditionally, seaweed grows by absorbing nutrients, so it can be said that it has a close relationship with oysters, which prey on phytoplankton that feed on nutrients. Therefore, there has been a need to develop a feed production system that can simultaneously produce nutrients and plankton and feed the produced feed to seaweed and oysters separately.

[0007] Patent Document 1 discloses a technology for concentrating seawater and using the plankton attached to a filter medium and culture medium layer as food. However, the inside of the filter device used has a complex structure with alternating filter medium layers and void layers, and since it is used submerged, inspection of the device is time-consuming. Furthermore, since aquatic organisms are cultivated inside the device, the device becomes large. Furthermore, in marine areas where oligotrophy is serious, there is a limit to how much plankton can be concentrated using only the capacity of the filter device.

[0008] Patent Document 2 discloses a technology for supplying seaweed with leaching water containing nitrogen and phosphorus components leached from a fertilizer material, thereby maintaining an appropriate concentration of nutrients in seawater. However, this technology requires separate preparation of fertilizer material to generate the leaching water, which is costly.

[0009] The present invention has been made in consideration of the above-mentioned problems, and provides a food production device for marine organisms, which is characterized by supplying seawater pumped from a sewage discharge area into which treated sewage containing nutrients such as nitrogen and phosphorus generated in the final sedimentation tank of a water treatment facility is discharged to a filtration device, and feeding the treated liquid containing plankton and nutrients obtained after the filtration process to oysters and seaweed, respectively. [Means for solving the problem]

[0010] This marine organism feed production system uses seawater from an area of ​​the ocean into which treated sewage treated at a water treatment facility is discharged to cultivate marine organisms.The system is equipped with a conveying section that takes in seawater from the sewage discharge area and supplies it to a filtration device, a filtration device that separates the seawater into suspended matter and a treated liquid, a feeding section that feeds the treated liquid to seaweed in a seaweed cultivation area, and a feeding section that feeds suspended matter removed by a cleaning fluid supplied from a cleaning fluid supply pipe connected to the filtration device to shellfish in a shellfish cultivation area together with the cleaning waste liquid.By doing so, it is possible to simultaneously produce food for seaweed and shellfish using a single filtration device.

[0011] The feeding section is configured to supply suspended matter detached by backwashing the filter layer to the shellfish cultivation area together with the cleaning wastewater, thereby enabling the suspended matter detached from the filter layer to be efficiently fed to the shellfish cultivation area.

[0012] The filtration device is configured so that a foam separation device is installed below the seawater supply pipe connected above, and the foam obtained by foam separation of the supplied seawater is supplied to the shellfish cultivation area from the feeding section, thereby allowing suspended matter contained in the stable foam to be fed to the shellfish cultivation area. [Effects of the Invention]

[0013] The feed production device of the present invention produces feed for seaweed and shellfish by filtering seawater pumped from a sewage discharge area into which treated sewage from a water treatment facility is discharged. This single device can produce feed for multiple marine organisms. The generated feed is fed to the aquaculture area, not the filtration device itself, so the device does not become too large. Furthermore, the filtration device has a simple configuration with filter media filled inside, making maintenance easy. It can also be easily applied to existing fishing grounds, as it only requires installation in any sea area. Furthermore, since the treated liquid is seawater from a sea area into which treated sewage containing nutrients is discharged, there is no need for additional fertilizers, and a treated liquid with the desired amount of plankton and the desired concentration of nutrients can be obtained, even in oligotrophic sea areas. Furthermore, the device is configured to perform foam separation during the filtration process, which prevents clogging of the filter media by suspended solids and allows for continuous filtration over long periods of time, enabling continuous feed production. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic diagram of a feed production device according to the present invention. FIG. [Figure 2] It is also a downward flow filtration device. DETAILED DESCRIPTION OF THE INVENTION

[0015] FIG. 1 is a schematic diagram of a feed production apparatus according to the present invention, and FIG. 2 is a downward flow filtration apparatus according to the present invention. As shown in Figure 1, the feed production device 1 of this embodiment includes a transport unit 3 that takes in treated liquid (seawater) from a sewage discharge area into which treated sewage treated in a water treatment facility is discharged and supplies it to a filtration device 2, the filtration device 2 that separates seawater into suspended matter and treated liquid, a feeding unit 4A that feeds the treated liquid to seaweed in a seaweed cultivation area, and a feeding unit 4B that feeds suspended matter removed by a cleaning fluid supplied from a cleaning fluid supply pipe 5 connected to the filtration device 2 together with the cleaning wastewater to shellfish in a shellfish cultivation area. Each component is described in detail below.

[0016] The transport section 3 consists of a seawater pump (not shown) installed in the sewage discharge area and a seawater supply pipe 6 connected to the seawater pump at one end and the filtration device 2 at the other end, and is configured to pump up seawater in the sewage discharge area and supply it to the filtration device 2.

[0017] Treated sewage discharged into sewage discharge areas is a liquid that has been biologically treated after solids have been removed from wastewater containing nutrients (such as nitrogen and phosphorus) such as human waste, sewage, and wastewater from food production and processing. Specifically, the liquid to be treated flowing into a sewage treatment plant is separated by sedimentation in a primary sedimentation tank, and the separated supernatant is biologically treated in a reaction tank supplied with oxygen, followed by further sedimentation in a final sedimentation tank. The supernatant may be disinfected and then used as treated sewage.

[0018] The supernatant liquid discharged from water treatment facilities is generally discharged into the sea, but the treatment methods described above cannot completely remove the nutrients contained in the treated liquid. For this reason, it can be said that the sewage discharge area into which treated sewage is discharged has a relatively high concentration of nutrients compared to other sea areas. In addition, sewage discharge areas with high nutrient concentrations also see the proliferation of phytoplankton (hereinafter referred to as plankton), which feed on nutrients, resulting in a high plankton concentration.

[0019] In this embodiment, seawater is pumped from a sewage discharge area where concentrations of nutrients and plankton are high, and the pumped seawater is supplied to the filtration device 2. The sewage discharge area in this embodiment is a closed water area with little water flowing in or out of the area from the outside, and is an ocean area where nutrients tend to accumulate.

[0020] As shown in Figure 2, the filtration device 2 is a downward flow filtration device in which a seawater supply pipe 6 is connected above a filtration tank 7, and seawater is supplied from above the filtration tank 7 and discharged from below. Inside the filtration tank 7, a filter media outflow prevention screen 8 is disposed at a predetermined height from the bottom of the tank, and a filter media layer 9 having a predetermined thickness is formed above the screen.

[0021] The filter layer 9 is formed by filling irregular granular fiber filter media, and captures suspended matter contained in seawater supplied from above the filter layer 9. Plankton is included in the suspended matter in the seawater, and by filtering the seawater, plankton can be obtained in the filter tank 7. Suspended matter in the seawater also includes organic matter derived from the carcasses and feces of living organisms, but the purpose of this embodiment is to obtain plankton, which serves as food for marine organisms (bivalves).

[0022] The filter material is not limited to fiber material, and other filter materials such as resin filter material and sand may be used. The diameter and shape may also be selected appropriately depending on the application. Depending on the conditions, the filter device 2 may be placed on a raft or the like to make it a floating type.

[0023] A cleaning fluid supply pipe 5 is connected below the filter tank 7, so that cleaning fluid can be supplied from below the filter tank 7 when cleaning the filter media. In this embodiment, a cleaning liquid supply pipe is used as the cleaning fluid supply pipe 5, and seawater (cleaning liquid) is supplied from below the filter tank 7 to clean the filter media, but if necessary, compressed air, a stirring blade, or the like may also be used in combination to agitate and clean the filter media. Furthermore, the cleaning fluid is not limited to seawater.

[0024] Furthermore, the filtration device 2 has a foam separation device 10 installed above the filtration tank 7. The foam separation device 10 is disposed below the seawater supply pipe 6 connected above the filtration tank 7, and is configured to perform foam separation on the seawater supplied from the seawater supply pipe 6.

[0025] The foam separator 10 is composed of an air diffuser pipe connected at one end to an air supply source such as a blower or compressor (not shown), and by driving the air supply source, fine bubbles are sprayed into the seawater from a large number of nozzle holes 12 formed at the top of the air diffuser pipe. By supplying the fine bubbles to the seawater, suspended matter in the seawater floats up and is separated, forming stable foam on the water surface.

[0026] The stable foam is supplied to the shellfish cultivation area from the feeding section 4B, which will be described in detail later. Since this stable foam contains plankton, the recovery rate of plankton can be increased by performing foam separation. Note that the foam separator 10 is not limited to the aeration tube type, as long as it generates fine bubbles.

[0027] The feeding section 4A is a pipe connected at one end to the bottom of the filtration tank 7 and at the other end to the seaweed cultivation area, and is configured to supply seawater (treated liquid) discharged after filtration to the seaweed cultivation area. The treated liquid supplied to the seaweed cultivation area has a high concentration of nutrients because it is seawater pumped from a sewage discharge area and filtered, where the concentration of nutrients is relatively high.

[0028] Nori grown in seaweed farming areas absorbs nutrients to grow, so supplying a treatment solution with a high concentration of nutrients promotes the growth of the nori, resulting in the production of high-quality nori that does not lose its color.

[0029] Meanwhile, feeding section 4B is a pipe with one end connected to the top of filter tank 7 and the other end connected to the shellfish cultivation area, and is configured so that plankton contained in the stable foam and plankton detached during cleaning of filter layer 9 can be supplied to the shellfish cultivation area together with the cleaning wastewater. The cleaning wastewater supplied to the shellfish cultivation area has a high plankton concentration because it is seawater pumped from a sewage discharge area and filtered, where the plankton concentration is relatively high.

[0030] Oysters cultivated in shellfish farming areas grow by capturing plankton, so supplying the oysters with effluent containing high concentrations of this plankton promotes their growth. [Example]

[0031] The feed production method according to this embodiment will be described in detail below with reference to FIGS. <Discharge process> In the discharge process, the treated sewage (supernatant) obtained after gravity settling in the final settling tank of the water treatment facility is discharged into any seawater (sewage discharge area).

[0032] <Transportation process> In the transport process, seawater is pumped up from the sewage discharge area by driving a seawater pump installed in the sewage discharge area, and the seawater is supplied to the filtration device 2 via the seawater supply pipe 6. At this time, the valve V1 installed in the seawater supply pipe 6 and the valve V2 installed in the feeding section 4A are open.

[0033] <Filtration process> In the filtration process, the pumped seawater is supplied to the filtration device 2 for filtration. Seawater is supplied from the seawater supply pipe 6 into the filtration tank 7, and fine bubbles are supplied from the nozzles 12 of the foam separator 10 toward the top of the filtration tank 7, while suspended solids are captured by the filter media layer 9 filled in the filtration tank 7. At this time, the valve V3 installed in the feeding section 4B is open.

[0034] The many fine bubbles that are ejected adsorb suspended matter mixed in the seawater supplied from above, as well as suspended matter that has naturally separated from the filter layer 9 due to the influence of water pressure, and rise to the water surface. Then, the bubbles that adsorb the suspended matter that rise one after another gather on the water surface, forming a stable foam on the water surface.

[0035] The stable foam formed on the water surface is supplied to the shellfish cultivation area from the feeding section 4B connected above the filtration tank 7. Since the stable foam contains plankton, which serves as food for the shellfish, it can be said that by performing foam separation during the filtration process, the food can be efficiently fed to the shellfish.

[0036] Foam separation is performed continuously during the filtration process, but the timing for starting the supply of compressed air is determined appropriately. The method for supplying stable foam from the feeding section 4B to the shellfish cultivation area can be selected appropriately, for example, by maintaining a constant water level in the filtration tank 7 and discharging the water by overflow during the filtration process. Depending on the conditions, the foam separation device 10 may be omitted and only the normal filtration process may be performed.

[0037] During the filtration process, plankton contained in the seawater passing through the filter layer 9 gradually accumulates on the filter layer 9. Meanwhile, the seawater that has passed through the filter layer 9 is supplied as a treated liquid from the feeding unit 4A to the seaweed cultivation area. The treated liquid supplied from the feeding unit 4A to the seaweed cultivation area contains fine bubbles sprayed from the foam separator 10, and supplying this treated liquid to the seaweed cultivation area promotes the growth of seaweed.

[0038] In this embodiment, the feed is produced using a downflow filtration device, but an upflow filtration device may also be used. In this case, the liquid to be treated (seawater) is supplied from the bottom of the filtration tank 7, the treated liquid discharged from the top of the filtration tank 7 is supplied to the seaweed cultivation area, and the plankton detached from the filter material by the cleaning liquid (seawater) supplied from above is supplied from the bottom of the filtration tank 7 to the shellfish cultivation area.

[0039] <Filter cleaning process> In the filter media cleaning process, the filter media layer 9 filled in the filter tank 7 is cleaned. A cleaning liquid is supplied from the downstream side of the filter media layer 9, and the water is passed through the filter media layer 9, and then discharged from the upstream side. This backwashing separates the plankton captured by the filter media layer 9. The separated plankton, together with the cleaning wastewater (seawater that has passed through the filter media layer 9) discharged from upstream of the filter media layer 9, is supplied to the shellfish cultivation area via the feeding section 4B.

[0040] The filter media cleaning process is performed, for example, when the filtration pressure increases due to clogging caused by suspended matter captured in the filter media layer 9 during the filtration process, when the cumulative operating time reaches a predetermined time or a predetermined time, or when the treated liquid no longer meets a predetermined standard. When cleaning the filter media, valves V1 and V2 are closed, and valve V4 installed in the cleaning liquid supply pipe 17 is opened.

[0041] Since seawater is used for washing, if a compressed air supply line is added below the washing fluid supply pipe 5, foam separation of the seawater supplied from the washing fluid supply pipe 5 will occur simultaneously with the agitation washing. Plankton is separated from the filter material by the agitation washing, and stable foam containing the plankton can be supplied from the feeding section 4B to the shellfish cultivation area, allowing for efficient production of feed.

[0042] In this embodiment, seaweed and oysters are listed, but the present invention is applicable to other marine organisms that feed on nutrients and plankton.

[0043] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. [Industrial Applicability]

[0044] This invention is a feed production device that filters seawater pumped from a sewage discharge area into which treated sewage containing nutrients is discharged, to produce nutrients and plankton that serve as feed for seaweed and shellfish. Because one filtration device can simultaneously produce feed for two or more types of marine organisms, this technology is effective for the aquaculture of all marine organisms that feed on nutrients and plankton. Furthermore, because it can be implemented using existing filtration devices, it can be easily applied to existing fishing grounds. [Explanation of symbols]

[0045] 2. Filtration equipment 3. Conveyor 4A, 4B feeding section 5. Cleaning fluid supply pipe 6 Seawater supply pipe 9 Filter layer 10 Foam separator

Claims

1. A marine organism feed production system that uses seawater from an area of ​​the ocean into which treated sewage treated at a water treatment facility is discharged for the cultivation of marine organisms, a conveying section (3) that takes in seawater from a sewage discharge area and supplies it to a filtration device (2); a filtration device (2) for separating seawater into suspended solids and a treated liquid; a feeding unit (4A) that feeds the treated liquid to seaweed in the seaweed cultivation area; a feeding section (4B) for feeding suspended matter separated by a cleaning fluid supplied from a cleaning fluid supply pipe (5) connected to the filtering device (2) together with the cleaning wastewater to shellfish in the shellfish cultivation area; A food production device for marine organisms.

2. The feeding section (4B) is configured to supply suspended matter separated by backwashing of the filter layer (9) together with the washing wastewater to the shellfish cultivation area.

2. The marine organism food production device according to claim 1.

3. The filtering device (2) is configured such that a foam separator (10) is installed below the seawater supply pipe (6) connected to the upper part, and the foam obtained by foam separation of the supplied seawater is supplied to the shellfish cultivation area from the feeding section (4B).

3. The marine organism food production device according to claim 2.

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