Systems and methods of gas infusion for aquaculture

Abstract

Gas infusion systems for aquaculture are provided. A recirculating aquaculture system (RAS) allows for a nearly closed-loop water circulation, with waste products managed or converted into non-toxic compounds. The RAS provides oxygenation and nitrogen removal in aquaculture applications. A gas infusion system employs advanced oxygenation technology to ensure optimal oxygen levels within a fish well, thereby enhancing the health and vitality of live fish during storage or transport. A gas stripping device utilizing microporous hollow fiber technology efficiently removes dissolved gases, such as CO2, from water to improve water quality, enhancing aquatic organism health, and optimizing aquaculture productivity.

Description

SYSTEMS AND METHODS OF GAS INFUSION FOR AQUACULTUREINCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

[0001] Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet as filed with the present application are hereby incorporated by reference under 37 CFR 1.57. This application claims priority to U.S. Provisional Patent Application No. 63 / 650,804, filed May 22, 2024.BACKGROUNDField

[0002] The present disclosure is directed to gas infusion systems and methods, and more particularly to gas infusion systems and methods for aquaculture, including for removal of carbon dioxide and / or oxygenation of water.Description of the Related Art

[0003] In a recirculating aquaculture system of various sizes from hatcheries to growing fish for market, the aquaculture water is purified and reused continuously. The produced waste products: solid waste, ammonium, and CO2, are either removed or converted into non-toxic products by the system components. It is, however, not possible to design a fully closed recirculating system. The non-degradable waste products must be removed and evaporated water must be replaced.

[0004] The utilization of live baitfish is integral to the success of recreational and competitive fishing, attracting predatory fish with their lively movements and enticing behavior. However, maintaining optimal oxygen levels within live fish wells is imperative for ensuring the health and vitality of baitfish. Inadequate oxygenation can lead to stressed or deceased baitfish, diminishing their efficacy as bait and undermining the overall fishing experience. Existing oxygenation systems may lack efficacy in oxygen transfer or overlook the critical task of removing nitrogen and CO2, thereby jeopardizing water quality and baitfish health.

[0005] Aquaculture systems face persistent challenges associated with the accumulation of dissolved gases, particularly CO2, which can significantly impact waterquality and aquatic organism health. Elevated concentrations of CO2 can lead to acidification, respiratory distress, altered behavior, and even mortality in aquatic species.SUMMARY

[0006] In accordance with one aspect of the disclosure, a recirculating aquaculture system (RAS) is provided that contains the following benefits or advantages: fully controlled environment for fish, low water usage, innovative water treatment design & processes, higher energy efficiency versus competitors, industry leading oxygen delivery to the fish environment that enhances fish health and growth rates, disease control, industry leading degassing processes, technologically advanced fish waste treatment, organic material management, scalable so that it can be used for small hatcher systems all the way through to growth-phase systems, and increased density, increased growth rates and lower mortality rates of fish.

[0007] In accordance with another aspect of the disclosure, micro-porous hollow fiber membrane technology is used to simultaneously oxygenate the water while removing nitrogen and CO2, guaranteeing high oxygen concentrations and a stable total gas pressure conducive to baitfish wellbeing in a live fish well.

[0008] In accordance with one aspect of the disclosure, a gas stripping device utilizing microporous hollow fiber technology efficiently removes dissolved gases from aquaculture systems. The oxygenation system for live fish wells on recreational boats or transport vessels harnesses the power of micro-porous hollow fiber membrane technology to efficiently transfer oxygen into the water while simultaneously removing nitrogen and CO2. This synergistic process ensures water with remarkably high levels of dissolved oxygen and sustains a consistent total gas pressure, thereby fostering the health and vitality of live baitfish. By extending the lifespan of baitfish and augmenting their allure to predatory fish, the system substantially enhances the likelihood of successful fishing trips for anglers. Notable features of the system include the utilization of a refillable compressed air tank for oxygen supply, adaptability to various live fish well configurations, user-friendly installation process, robust stainless steel construction ensuring longevity, virtually maintenance-free operation, resilient long-life motor, self-cleaning functionality, lightweight design facilitating effortless redeployment, preservation of total gas pressure in the water, and reduction of nitrogen levels within the aquatic environment.

[0009] In some aspects, the techniques described herein relate to a gas removal system for aquaculture, including: an elongated hollow housing having a mixing chamber; a water inlet at a distal portion of the housing; a water outlet at a proximal portion of the housing; a gas outlet at a proximal end of the housing; a disc with a plurality of hollow fibers extending therethrough, the disc disposed distal to the water inlet so that the water inlet is disposed between the disc and the mixing chamber; and a gas inlet in fluid communication with a plenum distal of the disc, the gas inlet being connectable to a gas source to deliver gas into the plenum and through the disc via the plurality of hollow fibers to generate a plurality of gas streams into the mixing chamber to mix with a water flow into the mixing chamber from the water inlet to strip carbon dioxide from the water flow and return the water flow via the water outlet, the stripped gas exiting via the gas outlet.

[0010] In some aspects, the techniques described herein relate to a gas removal system for aquaculture, including: a gas infusion unit configured to be disposed in a live fish well or fish tank containing fresh or salt water, the gas infusion unit having a housing with a water inlet, a water outlet and a plurality of micro-porous hollow fibers disposed in the housing; a pump mounted to a proximal end of the gas infusion unit and operable to flow the water through the water inlet into the housing; a compressed gas supply tank; and a gas flow meter in fluid communication with the supply tank and with a gas inlet of the gas infusion unit, wherein the supply tank delivers gas into the gas infusion unit and through the plurality of micro-porous hollow fibers to mix with and infuse a water flow flowed into the housing via the water inlet with the gas and to simultaneously extract nitrogen and carbon dioxide from the water flow before returning the water flow to the tank.

[0011] In some aspects, the techniques described herein relate to a gas removal system for aquaculture, including: a fish tank with fresh or salt water; a drum filter in fluid communication with and downstream of the fish tank and configured to receive a flow of water therefrom, the drum filter operable to separate coarse solids from the water flow; a sedimentation filter in fluid communication with and downstream of the drum filter, the sedimentation filter operable to separate non-soluble solid particles from the water flow; a biological aerated reactor in fluid communication with and downstream of the sedimentation filter, the reactor operable to convert organic matter to carbon dioxide and ammonia to nitrogen dioxide and nitrate; one or more gas infusion membranes in fluid communication with thebiological aerated reactor and configured to receive at least a portion of an outflow from the biological aerated reactor and configured to saturate the outflow with oxygen before returning the outflow to the biological aerated reactor; an ultraviolet light system in fluid communication with and downstream of the biological aerated reactor, the ultraviolet light system operable to disinfect the water flow from the biological aerated reactor before flowing said water flow to the fish tank; and one or more gas infusion membranes in fluid communication with the fish tank and configured to receive at least a portion of a water flow from the fish tank and configured to saturate said water flow with oxygen before returning the water flow to the fish tank.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic view of a gas infusion system for aquaculture.

[0013] Figure 2 is a schematic view of a gas infusion system installed in a live fish well tank.

[0014] Figure 3 is a schematic perspective view of an air lift assembly.

[0015] Figure 4A is a schematic perspective view of the air lift assembly.

[0016] Figure 4B is a schematic side view of the air lift assembly.

[0017] Figure 4C is a schematic front view of the air lift assembly.

[0018] Figure 4D is a schematic cross-sectional view of the air lift assembly along line A-A in FIG. 4C.

[0019] Figure 4E is a schematic top view of an air lift assembly.

[0020] Figure 5A is a schematic perspective view of an air lift assembly.

[0021] Figure 5B is a schematic enlarged partial perspective view of the air lift assembly.

[0022] Figure 5C is a schematic enlarged cross-sectional side view of the air lift assembly in FIG. 5B.

[0023] Figure 6 is a schematic perspective view of the air lift assembly.

[0024] Figure 7 is a schematic view of a gas infusion module prior to cutting of a disc therefrom.

[0025] Figure 8 is a schematic perspective view of the gas infusion disc following to cutting of the gas infusion module.

[0026] Figure 9 is a top view of the disc of FIG. 8.

[0027] Figure 10 is a cross-sectional view of the disc of FIG. 8 along the midline of the disc in FIG. 9.DETAILED DESCRIPTIONRecirculating Aquaculture System (RAS)

[0028] In the realm of aquaculture, effective removal of organic matter and nutrients, particularly nitrogen, from fish tanks is paramount. The utilization of oxygeninfusion technology facilitates highly efficient treatment, achieving up to 97% oxygen transfer to liquid, thus minimizing pure oxygen usage and energy consumption. This technology also saturates purified water with oxygen before returning it to the fish tanks, ensuring optimal conditions for aquatic life. A recirculating aquaculture system (RAS) 1 allows for a nearly closed-loop water circulation, with waste products managed or converted into non-toxic compounds. The inventive RAS system emphasizes controlled environments for fish, innovative water treatment, energy efficiency, and enhanced oxygen delivery, among other goals. Various stages in the RAS process, including preliminary treatment, sedimentation, biological filtration, and disinfection, are detailed. Automation, pH control, waste management, and UV disinfection are integrated for comprehensive water treatment. Ultimately, the inventive system described herein contributes significantly to oxygenation and nitrogen removal in aquaculture applications, offering diverse benefits for fish health and system efficiency.

[0029] The first process step of a RAS system 1 (see FIG. 1) is a preliminary treatment for the steps downstream. A Drum Filter 10 is necessary for coarse solids separation from the Fish Tanks 20. This step is important to protect the following or downstream operational units. The equipment is designed to operate with Level controls up and downstream. Due to the clogging of the filter screen the water level inside the drum will rise. As a result, the flushing mechanism 30 is put into operation. The drum starts to rotate, and from the outside of the drum water is sprayed under high pressure from nozzles through the filter cloth, hereby flushing the waste particles from the screen. Together with the waste particles the water is discarded in the gutter or dumpster 40. Different filter screens can be chosen depending on fish species and fish size.

[0030] The water flowing from the Drum Filters 10 is led through a sedimentation tank 50. In the sedimentation tank 50 the non-soluble, solid particles are separated from thesystem water using gravity. The sedimentation tank 50 is filled with a specially adapted polypropylene filter pack. The solids are allowed to settle on these filters. The settled particles form a layer of silt on the bottom of the sedimentation tank 50. This silt is biologically very active: up to 60% of the nitrates produced by a biological aerated reactor or biological filter or biofilter 60 are denitrified by the bacteria in the silt and turned into nitrogen gas. Therefore, for the total nitrogen purposes (nitrate removal purposes) it is an important process step to be considered. Some parameters can be monitored, such as final nitrate and nitrite levels, oxidation reduction potential (ORP) and the Dissolved Oxygen (DO) inside it (as the environment should be controlled as anoxic - ORP between a-50 and +50 mV and Dissolved Oxygen close to zero).

[0031] The step after is the biological aerated reactor or biological filter 60 is followed by a secondary clarifier 70, which is optional depending on the type of reactor adopted. This step in the process (e.g., of operation of the biological aerated reactor 60) is basically an aeration biological treatment, in which organic matter is converted into carbon dioxide (CO2), and ammonia (NH3) (that is toxic to fishes in high concentrations) is converted into nitrogen dioxide (NO2) and nitrate (NO3) by nitrifying bacteria. This process can be done in many different ways, like with a MBBR (Moving Bed Biological Reactor), FBR (Fixed Bed Biological reactor), Activated Sludge with Suspended Solids, and others. The inventive Gas Infusion technology is applied exactly in this process step of the RAS system 1. Part of the Biological Filter outflow is recirculated through Gas Infusion membranes 80 (e g., having a plurality of microporous hollow fibers, such as those described herein), which is also connected to a source of pure oxygen 90 (e.g., conventionally oxygen generators, such as pressure swing adsorption (PSA) or vacuum swing adsorption (VSA) equipment). After crossing the Gas Infusion membranes 80 in one single pass, this flow is now oversaturated of oxygen (60-400 ppm), providing the necessary oxygen demand for the biological activity and, consequently, for the removal of organic matter and ammonia ionized, and the flow is returned to the biological aerated reactor or biological filter 60.

[0032] The automation of the process is, in one example, based on the set point control of the Dissolved Oxygen inside the biological filter 60: if the measured Dissolved Oxygen rises, the valves from the oxygen generators 90 to the Gas Infusion membranes 80reduces its opening. Other monitoring probes, like ammonia (NH3), total suspended solids (TSS), Turbidity, Total Phosphorus and pH, can also be applied.

[0033] As the nitrification reaction reduces the pH, some automation can be added connecting this probe with an alkalinity source, in order to keep the pH level around 7.0.

[0034] From the biological treatment there is a waste solid stream to be dewatered and disposed. For this purpose, a centrifuge 75 and a polymer dosing 77 are necessary in order to achieve, in one example, around 20-25% dry solids and reduce the amount of volume to be transported and disposed.

[0035] Following the biological process in the biological aerated reactor or biological filter 60, an ultraviolet (UV) light system 100 can be used for disinfection purposes, before the liquid stream is directed to the fish tanks 20. The solids were eliminated at the clarifier of the step before and now, a monitoring of the Turbidity downstream of the clarifier 70 is also recommended as UV lights have a better disinfection performance with low turbidity levels. This light is electromagnetic radiation just below the visible light spectrum. The wavelength of UV-C light is 200-280 nanometers.

[0036] UV-C light is highly germicidal and has an antiseptic effect. With the use of irradiation of UV-C light to a contaminated surface, or in running water, it is possible to control excessive growth of micro-organisms including bacteria. UV disinfection is a proven method to kill off bacteria, viruses and fungi, but first and foremost to keep the system water clear and free of small particles even at low dosage.

[0037] At the final step of the liquid stream, the water from the fish tanks 20 passes through the Gas Infusion membranes 85 (e.g., having a plurality of microporous hollow fibers, such as those described herein) where the oxygenation process for the fish tanks 20 occurs in a recirculation of a portion of the total flow of the RAS system 1. Part of the water flow from the fish tanks 20 or the final purified water of the stream pass though the Gas Infusion membranes 85, also connected to the pure oxygen source 90 (oxygen generators) and returns back to the fish tanks 20, bringing the fish oxygen needed to support respiration, health and growth. The inventive Gas Infusion’s advantages of the RAS system 1 for this use include: o Removes nitrogen and ammonia in aquaculture applications, while simultaneously infusing oxygen at desired levels.o Does not increase the Total Gas Pressure of the water used in the aquaculture growth system. o Does not cause Fish Bubble Disease. o Reduces Mortality rates of fish and aquatic life in warm water environments. o Effective in both fresh and saltwater. o The invented technology is the unique technology with the capability of degassing carbon dioxide (CO2), nitrogen gas (N2), non-ionized water at the same time that dissolves and introduces significant and stable amounts of oxygen (02).Live Fish Well

[0038] Disclosed herein is a gas infusion system 100A, such as an oxygenation system, specifically designed for live fish wells on recreational boats or other fish holding vessels used for recreational or competitive fishing, or for commercial transport. The system employs advanced oxygenation technology to ensure optimal oxygen levels within the fish well, thereby enhancing the health and vitality of live fish during storage or transport. Advantageous features include adjustable oxygen output, compact design, user-friendly operation, energy efficiency, and durability.

[0039] FIG. 2 shows a gas infusion system 100A in a live fish well or fish tank 101 A that contains fresh or salt water 105 A. The system can receive power via an electrical power cord 102A. In another example, the system can (additionally or alternatively) receiver power from a battery pack. The system can have a gas flow meter 103 A for controlling the flow of compressed air or oxygen from the compressed air or oxygen supply tank 104A (e.g., with a regulator) to the gas infusion unit 106A. The gas infusion unit 106A can be an oxygen infuser which contains (a plurality of) micro-porous hollow fibers that transfers oxygen into water at 75% efficiency or greater (e.g., 80%, 85%, 97%) into either fresh or salt water. The oxygen infuser or gas infusion unit 106A has a small pump 107A mounted to the top of the gas infusion unit 106A that circulates water through the module(s) of the gas infusion unit 106A and over the fiber(s), while oxygen is introduced through the microporous hollow fibers in the gas infusion unit 106A and exit the fibers through their micropores (e.g., sized between 0.01 gm and 5 pm, such as 0.1 pm, 1 pm, etc.) into the water flow to infuse the water flow (in a bubbleless manner) with gas (e.g., oxygen). In one example, water enters via inlet 109A intothe housing of the gas infusion unit 106A and the oxygen infused water exits the gas infusion unit 106A via apertures 108 A in a housing of the gas infusion unit 106A. Gas enters the gas infusion unit 106A via a gas inlet 110A and flows through the micro-porous hollow fibers in the housing of the gas infusion unit 106, the gas exiting the fibers via the micropores in the walls of the fibers to infuse the water flowing through the gas infusion unit 106A with gas (e.g., air, oxygen) and simultaneously displace nitrogen and carbon dioxide from the water before the water exists the gas infusion unit 106A via the water outlet or apertures 108A.1. Oxygenation and Gas Removal Mechanism:

[0040] The system 100A employs a micro-porous hollow fiber membrane infuser (inside the gas infusion unit 106A) to adeptly facilitate the transfer of oxygen into the water (e g., in a bubbleless manner) while simultaneously extracting nitrogen and carbon dioxide from the water (CO2). The gas transfer of oxygen into the water is achieved by the gas infusion unit 106A at a transfer efficiency of 75% or greater into either fresh or salt water. This dual functionality (e.g., of infusion the water with oxygen while simultaneously removing nitrogen and carbon dioxide) advantageously ensures water with extraordinarily high levels of dissolved oxygen and maintains a stable total gas pressure (e.g., of the water 105A in the tank 101A), thereby creating an optimal environment for the health and vitality of live baitfish.2. Refillable Compressed Air Tank:

[0041] To ensure continuous oxygenation of the water within the tank 101A (e.g., live fish well tank), the system 100A integrates a refillable compressed air tank 104A as the oxygen source. This ensures uninterrupted oxygen supply, enhancing the system's efficiency and reliability. In another example, the tank 104A is filled with pure oxygen.3. Heat Loss Prevention:

[0042] Unlike conventional oxygenation systems that may experience heat loss due to degassing, the micro-porous hollow fiber membrane technology effectively prevents heat dissipation, thereby preserving water temperature stability and minimizing stress on live baitfish.4. Compatibility and Deployment:

[0043] The system 100A is designed to seamlessly integrate into any type of live fish well or water reservoir commonly found on recreational boats or hand transport water vessels, accommodating diverse sizes and configurations. Its versatile design ensures optimal performance in various aquatic environments.5. Installation and Construction:

[0044] Installation of the system 100A is straightforward and user-friendly, requiring minimal tools and expertise. Constructed from robust materials, the system 100A boasts exceptional durability and corrosion resistance, ensuring longevity even in harsh marine conditions.6. Maintenance and Longevity:

[0045] With its virtually maintenance-free operation, the system 100 A minimizes the need for user intervention, providing anglers with hassle-free fishing experiences. Its longlife (pump) motor and self-cleaning functionality further contribute to its reliability and longevity.7. Nitrogen Reduction:

[0046] By effectively removing nitrogen from the aquatic environment, the system 100A advantageously mitigates the accumulation of harmful compounds and preserves water quality in the aquatic environment, benefiting both baitfish and gamefish populations. This reduction in nitrogen levels fosters a healthier ecosystem within the live fish well, promoting the overall wellbeing of aquatic life.

[0047] In conclusion, the gas infusion (e.g., oxygenation) system 100A for live fish wells on recreational boats represents a significant advancement in live baitfish management and fishing technology. Its innovative design, coupled with versatile functionality and user- friendly features, not only enhances the fishing experience but also contributes to the conservation of aquatic ecosystems. By ensuring the health and vitality of live baitfish while maintaining water quality and stability, the system empowers anglers to enjoy successful and sustainable fishing excursions.Air lift and Gas Removal System

[0048] Aquaculture systems frequently encounter challenges arising from elevated concentrations of dissolved gases, particularly carbon dioxide (CO2), which can detrimentally affect water quality and aquatic organism health. To address these issues, a novel gas stripping device utilizing microporous hollow fiber technology has been developed, which employs a specially designed potted disk containing over 10,000 microporous hollow fibers, ranging from 250 to 450 microns (pm) in diameter, to efficiently remove dissolved gases from water.

[0049] With reference to FIGS. 3-10, an air lift system 250 includes a housing 251 (e.g., hollow tube, hollow elongate pipe) a water injection point or inlet 210, a mixing chamber 220, a water outlet 230, a gas outlet 240, and a gas stripping device 200. In conjunction with an air lift pump (not shown) that can be connected to a gas inlet 205, the gas stripping device 200 facilitates the stripping of CO2 and other dissolved gases from the water. The gas stripping device’s 200 compact footprint, minimal disruption to the aquatic environment, and ability to maintain CO2 levels below 20 mg / liter make it a valuable tool for improving water quality, enhancing aquatic organism health, and optimizing aquaculture productivity.

[0050] The gas stripping device 200 consists of a specially designed disc 200 (potted disc) containing, in one example, over 10,000 microporous hollow fibers (MHF) 202. The MHF 202 can each range in diameter from 250 to 450 microns. In one example, each of the microporous hollow fibers 202 can have an inner diameter of 0.1 pm. These hollow fibers 202 are arranged in a densely packed configuration within the disc 200, creating a narrow vertical pathway for the source gas passing through the hollow fibers 202 in order to create a multitude of narrow vertical streams of gas that rise through the water column (e.g., through the mixing chamber 220 as the water flows from the water inlet 210 to the water outlet 230). The disc 200 is disposed or installed proximate (e.g., adjacent) the water injection point 210, with the water injection point 210 being between the disc 200 and the mixing chamber 220 within an air lift system 250. An air lift pump (not shown) can be connected to an inlet 205 (gas inlet coupling) attached to the housing 251 of the air lift system 250 to deliver gas (e.g., air, oxygen) into a plenum 207 between the disc 200 and the bottom end of the air lift system 250. The disc 200 (e.g., potted disk) can be made by dipping the fibers 202 into epoxy in a mold, allowing the epoxy to solidify into a solid block, and then machining the solid block of epoxy (e.g., with a lathe) to provide the completed disc 200 (e.g., so that the fibers 202 extendcompletely through the block so that openings of the fibers 202 are exposed on both sides of the block of the disc 200). The block can be encased in or surrounded by a ring 201, which in one example can have a diameter of three inches. In one example, the ring 201 can be a schedule 40 polyvinyl chloride (PVC) pipe portion; however, the ring 201 can be made of other suitable materials. Further details on the potting process can be found in in PCT Application Nos. PCT / US2023 / 076987 filed 10 / 26 / 2023, which is incorporated herein by reference in its entirety.

[0051] The disc 200 is advantageously compact and can have a thickness T that can, in some examples, be between about 14 inch and about 1 inch, such as about 14 inch. However, the thickness T can have other suitable values. In one example, the block of the disc 200 can have an outer diameter OD of about 3 14 inches and have a section with the fibers 202 with a diameter ID of about 3 inches. However, the block of the disc 200 can have other suitable outer diameters OD and diameters ID.

[0052] The air lift system 250 can have a height L, in one example, of between about 4 feed and about 6 feet (e.g., about 5 feet, 64 inches or 16.25 m). However, the air lift system 250 can have other suitable lengths. In one example, the housing 251 can be a three inch schedule 40 pipe. However, the housing can have other suitable diameters. In one example, the housing 251 can be made of polyvinyl chloride (PVC). However, the housing 251 can be made of other suitable materials (e.g., other suitable plastic materials, suitable metals, etc.).

[0053] With reference to FIG. 5C, the water injection point or inlet 210, disc 200 and plenum 207 can be in a sleeve portion 252 that can be attached to the housing 251 (e.g., attached over a distal portion of the housing 251), facilitating the assembly of the air lift system 250. The water outlet 230 and gas outlet 240 can be part of a T-shaped connector 253 (see FIG. 5A) that can be attached to the housing 251 (e.g., attached over a proximal portion of the housing 251), facilitating the assembly of the air lift system 250.

[0054] In use, water enters the housing 251 of the air lift system 250 via one or more (e.g., a plurality of) apertures 212 of the water injection point or inlet 210 (e.g., a circumferential mesh, a circumferential grill) and flows upward within the housing 251 toward the water outlet 230 (e.g., pumped by a pump, not shown, into the water injection point or inlet 210). A gas (e.g., air, oxygen, etc.) is injected into the plenum 207 via the inlet 205 (e.g., thatis connected to an air lift pump or gas source). Said gas passes from the plenum 207 into the disc 200 via the fibers 202 and passes through the disc 200 via the fibers 202 and into the mixing chamber 220 as a plurality of gas (e.g., air) columns, where the gas mixes with the water flowing through the housing 251. As water flows through the mixing chamber 220, dissolved gases, such as CO2, are stripped from the water column as said injected air or other infused gases rise through the mixing chamber 220 of the air lift system 250 in one or more (e.g., a plurality of) streams of nano bubbles. The stripped water then continues through the housing 251 of the air lift system 250, free from excess gases and exits through the water outlet 230, thereby improving water quality and creating a more hospitable environment for aquatic organisms. The stripped gas (e.g., CO2) exits the housing 251 of the air lift system 250 via a gas outlet 240 that is separate from the water outlet 230. In one example, the gas outlet 240 is at 90 degrees to the water outlet 230 (e.g., the gas outlet 240 and water outlet 230 can be part of a T-junction in a pipe connector attached to the housing 251).Advantages:

[0055] 1. Efficient Gas Stripping: The microporous hollow fiber gas stripping disc200 enables efficient removal of dissolved gases, ensuring optimal water quality in aquaculture systems.

[0056] 2. Compact and Space-Efficient: The device's compact footprint allows for easy integration into existing aquaculture environments without requiring significant additional space.

[0057] 3. Minimal Disruption to Aquatic Environment: The design of the gas stripping device ensures smooth water flow and does not interfere with fish movement or cause harm to aquatic organisms.

[0058] 4. Versatile Application: The device can be adapted to various aquaculture configurations and scaled to accommodate different water volumes and flow rates.

[0059] 5 Consistent CO2 Levels: The gas stripping device maintains CO2 levels below 20 mg / liter, promoting optimal conditions for aquatic species health and growth.Additional Embodiments

[0060] In examples of the present disclosure, a gas removal system for aquaculture and method of operation may be in accordance with any of the following clauses:

[0061] Clause 1 . A gas removal system for aquaculture, comprising: an elongated hollow housing having a mixing chamber; a water inlet at a distal portion of the housing; a water outlet at a proximal portion of the housing; a gas outlet at a proximal end of the housing; a disc with a plurality of hollow fibers extending therethrough, the disc disposed distal to the water inlet so that the water inlet is disposed between the disc and the mixing chamber; and a gas inlet in fluid communication with a plenum distal of the disc, the gas inlet being connectable to a gas source to deliver gas into the plenum and through the disc via the plurality of hollow fibers to generate a plurality of gas streams into the mixing chamber to mix with a water flow into the mixing chamber from the water inlet to strip carbon dioxide from the water flow and return the water flow via the water outlet, the stripped gas exiting via the gas outlet.

[0062] Clause 2. The system of clause 1, wherein the water inlet comprises a screen with a plurality of apertures.

[0063] Clause 3. The system of any preceding clause, wherein the water outlet and gas outlet are part of a T-shaped connector attached to the housing.

[0064] Clause 4. The system of any preceding clause, wherein the water outlet and the gas outlet are at 90 degrees to each other.

[0065] Clause 5. The system of any preceding clause, wherein each of the plurality of hollow fibers has an inner diameter of about 0.1 pm.

[0066] Clause 6. The system of any preceding clause, wherein water inlet and disc are part of a sleeve portion attached to the housing.

[0067] Clause 7. The system of any preceding clause, wherein the disc has a thickness of about ‘ inch.

[0068] Clause 8. The system of any preceding clause, wherein the plurality of hollow fibers are encased in a block of cured material.

[0069] Clause 9. A gas removal system for aquaculture, comprising: a gas infusion unit configured to be disposed in a live fish well or fish tank containing fresh or salt water, the gas infusion unit having a housing with a water inlet, a water outlet and a plurality of micro- porous hollow fibers disposed in the housing; a pump mounted to a proximal end of the gas infusion unit and operable to flow the water through the water inlet into the housing; a compressed gas supply tank; and a gas flow meter in fluid communication with the supply tank and with a gas inlet of the gas infusion unit, wherein the supply tank delivers gas into the gasinfusion unit and through the plurality of micro-porous hollow fibers to mix with and infuse a water flow flowed into the housing via the water inlet with the gas and to simultaneously extract nitrogen and carbon dioxide from the water flow before returning the water flow to the tank.

[0070] Clause 10. The system of clause 9, wherein the water outlet is a plurality of apertures.

[0071] Clause 11. The system of any of clauses 9-10, wherein the pump is powered via an electrical power cord.

[0072] Clause 12. The system of any of clauses 9-11, wherein the gas is oxygen or air.

[0073] Clause 13. The system of any of clauses 9-12, wherein the micro-porous hollow fibers transfer the gas into the water at an efficiency of 75% or greater.

[0074] Clause 14. The system of any of clauses 9-13, wherein the micro-porous hollow fibers have a pore size of between 0.01 pm and 5 pm.

[0075] Clause 15. The system of any of clauses 9-14, wherein the gas infusion unit operates to infuse the water flow with the gas and to remove nitrogen and carbon dioxide from the water flow to maintain a stable total gas pressure in the water in the tank.

[0076] Clause 16. A gas removal system for aquaculture, comprising: a fish tank with fresh or salt water; a drum filter in fluid communication with and downstream of the fish tank and configured to receive a flow of water therefrom, the drum filter operable to separate coarse solids from the water flow; a sedimentation filter in fluid communication with and downstream of the drum filter, the sedimentation filter operable to separate non-soluble solid particles from the water flow; a biological aerated reactor in fluid communication with and downstream of the sedimentation filter, the reactor operable to convert organic matter to carbon dioxide and ammonia to nitrogen dioxide and nitrate; one or more gas infusion membranes in fluid communication with the biological aerated reactor and configured to receive at least a portion of an outflow from the biological aerated reactor and configured to saturate the outflow with oxygen before returning the outflow to the biological aerated reactor; an ultraviolet light system in fluid communication with and downstream of the biological aerated reactor, the ultraviolet light system operable to disinfect the water flow from the biological aerated reactor before flowing said water flow to the fish tank; and one or more gas infusion membranes influid communication with the fish tank and configured to receive at least a portion of a water flow from the fish tank and configured to saturate said water flow with oxygen before returning the water flow to the fish tank.

[0077] Clause 17. The system of clause 16, further comprising a secondary clarifier in fluid communication with and downstream of the biological aerated reactor, and upstream of the ultraviolet light system.

[0078] Clause 18. The system of any of clauses 16-17, further comprising an oxygen generator operable to supply the gas infusion membranes in fluid communication with the fish tank and the gas infusion membranes in fluid communication with the biological aerated reactor with oxygen.

[0079] Clause 19. The system of any of claims 16-18, wherein the gas infusion membranes operate to infuse the water flow from the fish tank with oxygen while maintaining a stable total gas pressure in the water in the fish tank.

[0080] Clause 20. The system of any of clauses 16-19, wherein the gas infusion membranes transfer oxygen to the water flow at an efficiency of up to 97%.

[0081] While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the disclosure. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions and changes in the systems and methods described herein may be made without departing from the spirit of the disclosure. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosure. Accordingly, the scope of the present inventions is defined only by reference to the appended claims.

[0082] Features, materials, characteristics, or groups described in conjunction with a particular aspect, embodiment, or example are to be understood to be applicable to any other aspect, embodiment or example described in this section or elsewhere in this specification unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. The protection is not restricted tothe details of any foregoing embodiments. The protection extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

[0083] Furthermore, certain features that are described in this disclosure in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations, one or more features from a claimed combination can, in some cases, be excised from the combination, and the combination may be claimed as a subcombination or variation of a subcombination.

[0084] Moreover, while operations may be depicted in the drawings or described in the specification in a particular order, such operations need not be performed in the particular order shown or in sequential order, or that all operations be performed, to achieve desirable results. Other operations that are not depicted or described can be incorporated in the example methods and processes. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the described operations. Further, the operations may be rearranged or reordered in other implementations. Those skilled in the art will appreciate that in some embodiments, the actual steps taken in the processes illustrated and / or disclosed may differ from those shown in the figures. Depending on the embodiment, certain of the steps described above may be removed, others may be added. Furthermore, the features and attributes of the specific embodiments disclosed above may be combined in different ways to form additional embodiments, all of which fall within the scope of the present disclosure. Also, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described components and systems can generally be integrated together in a single product or packaged into multiple products.

[0085] For purposes of this disclosure, certain aspects, advantages, and novel features are described herein. Not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art willrecognize that the disclosure may be embodied or carried out in a manner that achieves one advantage or a group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.

[0086] Conditional language, such as “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, and / or steps. Thus, such conditional language is not generally intended to imply that features, elements, and / or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements, and / or steps are included or are to be performed in any particular embodiment.

[0087] Conjunctive language such as the phrase “at least one of X, Y, and Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to convey that an item, term, etc. may be either X, Y, or Z. Thus, such conjunctive language is not generally intended to imply that certain embodiments require the presence of at least one of X, at least one of Y, and at least one of Z.

[0088] Language of degree used herein, such as the terms “approximately,” “about,” “generally,” and “substantially” as used herein represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms “approximately”, “about”, “generally,” and “substantially” may refer to an amount that is within less than 10% of the stated amount. As another example, in certain embodiments, the terms “generally parallel” and “substantially parallel” refer to a value, amount, or characteristic that departs from exactly parallel by less than or equal to 15 degrees.

[0089] The scope of the present disclosure is not intended to be limited by the specific disclosures of preferred embodiments in this section or elsewhere in this specification, and may be defined by claims as presented in this section or elsewhere in this specification or as presented in the future. The language of the claims is to be interpreted broadly based on the language employed in the claims and not limited to the examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive.

[0090] Of course, the foregoing description is that of certain features, aspects and advantages of the present invention, to which various changes and modifications can be made without departing from the spirit and scope of the present invention. Moreover, the devices described herein need not feature all of the objects, advantages, features and aspects discussed above. Thus, for example, those of skill in the art will recognize that the invention can be embodied or carried out in a manner that achieves or optimizes one advantage or a group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein. In addition, while a number of variations of the invention have been shown and described in detail, other modifications and methods of use, which are within the scope of this invention, will be readily apparent to those of skill in the art based upon this disclosure. It is contemplated that various combinations or subcombinations of these specific features and aspects of embodiments may be made and still fall within the scope of the invention. Accordingly, it should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the discussed devices.

Claims

WHAT IS CLAIMED IS:

1. A gas removal system for aquaculture, comprising: an elongated hollow housing having a mixing chamber; a water inlet at a distal portion of the housing; a water outlet at a proximal portion of the housing; a gas outlet at a proximal end of the housing; a disc with a plurality of hollow fibers extending therethrough, the disc disposed distal to the water inlet so that the water inlet is disposed between the disc and the mixing chamber; and a gas inlet in fluid communication with a plenum distal of the disc, the gas inlet being connectable to a gas source to deliver gas into the plenum and through the disc via the plurality of hollow fibers to generate a plurality of gas streams into the mixing chamber to mix with a water flow into the mixing chamber from the water inlet to strip carbon dioxide from the water flow and return the water flow via the water outlet, the stripped gas exiting via the gas outlet.

2. The system of claim 1, wherein the water inlet comprises a screen with a plurality of apertures.

3. The system of any preceding claim, wherein the water outlet and gas outlet are part of a T-shaped connector attached to the housing.

4. The system of any preceding claim, wherein the water outlet and the gas outlet are at 90 degrees to each other.

5. The system of any preceding claim, wherein each of the plurality of hollow fibers has an inner diameter of about 0.1 pm.

6. The system of any preceding claim, wherein water inlet and disc are part of a sleeve portion attached to the housing.

7. The system of any preceding claim, wherein the disc has a thickness of about 14 inch.

8. The system of any preceding claim, wherein the plurality of hollow fibers are encased in a block of cured material.

9. A gas removal system for aquaculture, comprising:a gas infusion unit configured to be disposed in a live fish well or fish tank containing fresh or salt water, the gas infusion unit having a housing with a water inlet, a water outlet and a plurality of micro-porous hollow fibers disposed in the housing; a pump mounted to a proximal end of the gas infusion unit and operable to flow the water through the water inlet into the housing; a compressed gas supply tank; and a gas flow meter in fluid communication with the supply tank and with a gas inlet of the gas infusion unit, wherein the supply tank delivers gas into the gas infusion unit and through the plurality of micro-porous hollow fibers to mix with and infuse a water flow flowed into the housing via the water inlet with the gas and to simultaneously extract nitrogen and carbon dioxide from the water flow before returning the water flow to the tank.

10. The system of claim 9, wherein the water outlet is a plurality of apertures.

11. The system of any of claims 9-10, wherein the pump is powered via an electrical power cord.

12. The system of any of claims 9-11, wherein the gas is oxygen or air.

13. The system of any of claims 9-12, wherein the micro-porous hollow fibers transfer the gas into the water at an efficiency of 75% or greater.

14. The system of any of claims 9-13, wherein the micro-porous hollow fibers have a pore size of between 0.01 pm and 5 pm.

15. The system of any of claims 9-14, wherein the gas infusion unit operates to infuse the water flow with the gas and to remove nitrogen and carbon dioxide from the water flow to maintain a stable total gas pressure in the water in the tank.

16. A gas removal system for aquaculture, comprising: a fish tank with fresh or salt water; a drum filter in fluid communication with and downstream of the fish tank and configured to receive a flow of water therefrom, the drum filter operable to separate coarse solids from the water flow; a sedimentation filter in fluid communication with and downstream of the drum filter, the sedimentation filter operable to separate non-soluble solid particles from the water flow;a biological aerated reactor in fluid communication with and downstream of the sedimentation filter, the reactor operable to convert organic matter to carbon dioxide and ammonia to nitrogen dioxide and nitrate; one or more gas infusion membranes in fluid communication with the biological aerated reactor and configured to receive at least a portion of an outflow from the biological aerated reactor and configured to saturate the outflow with oxygen before returning the outflow to the biological aerated reactor; an ultraviolet light system in fluid communication with and downstream of the biological aerated reactor, the ultraviolet light system operable to disinfect the water flow from the biological aerated reactor before flowing said water flow to the fish tank; and one or more gas infusion membranes in fluid communication with the fish tank and configured to receive at least a portion of a water flow from the fish tank and configured to saturate said water flow with oxygen before returning the water flow to the fish tank.

17. The system of claim 16, further comprising a secondary clarifier in fluid communication with and downstream of the biological aerated reactor, and upstream of the ultraviolet light system.

18. The system of any of claims 16-17, further comprising an oxygen generator operable to supply the gas infusion membranes in fluid communication with the fish tank and the gas infusion membranes in fluid communication with the biological aerated reactor with oxygen.

19. The system of any of claims 16-18, wherein the gas infusion membranes operate to infuse the water flow from the fish tank with oxygen while maintaining a stable total gas pressure in the water in the fish tank.

20. The system of any of claims 16-19, wherein the gas infusion membranes transfer oxygen to the water flow at an efficiency of up to 97%.

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