Harmful algae bloom mitigation system

Abstract

A large-scale harmful algae bloom mitigation system that is environmentally safe, cost-effective, and scalable utilizing a hyperoxic nanobubble treatment and remote brevetoxin screening, without relying on heavy laboratory equipment. The hyperoxic nanobubble treatment and remote brevetoxin screening system is configured for installation within a narrow cross-section of an area of a body of water. The system is a stationary, high oxygen concentration, gas flow system that injects a large amount of oxygen enriched nanobubbles underwater at a small cross-section of a body of water, thereby controlling a large amount of water rapidly and in an environmentally-safe manner.

Claims

1. A hyperoxic nanobubble water treatment system for use within a body of water, the system comprising: a first end proximate to a first shoreline of the body of water, and a second end opposite the first end, the second end proximate to a second shoreline of the body of water; and a nanobubble generator spanning from the first end to the second end, the nanobubble generator including: a linear tube disposed between the first end and the second end, the linear tube defining at least one aperture therein; and at least one nozzle disposed through the at least one aperture defined by the linear tube, the at least one nozzle extending in a direction away from the linear tube and into the body of water, wherein the nanobubble generator, via the at least one nozzle, generates a plurality of hyperoxic nanobubbles and ejects the plurality of hyperoxic nanobubbles into the body of water, such that each of the plurality of hyperoxic nanobubbles forms an absorption and reaction site on a surface thereof to bind to a brevetoxin cell, thereby reducing brevetoxin growth and photosynthesis.

2. The system of claim 1, further comprising a plurality of apertures defined within the linear tube.

3. The system of claim 2, further comprising a plurality of nozzles, each of the plurality of nozzles disposed through one of the plurality of apertures defined within the linear tube.

4. The system of claim 3, wherein each of the plurality of nozzles includes a diameter of between 5 nanometers and 500 nanometers.

5. The system of claim 3, wherein each of the plurality of nozzles is angled with respect to the linear tube, the angle being between 45 and 135.

6. The system of claim 1, wherein the first end and the second end of the system are spaced apart by a length of 10-1000 meters.

7. The system of claim 1, wherein at least one of the first end and the second end is disposed on at least one of the first shoreline and the second shoreline.

8. The system of claim 1, wherein the linear tube extends from the first end to the second end of the system.

9. The system of claim 1, wherein the linear tube includes a length of between 10 meters and 30 meters.

10. The system of claim 1, wherein the linear tube includes a first portion having a first diameter and a second portion having a second diameter, the second diameter being smaller than the first diameter, thereby creating a gradient from the first portion to the second portion of the linear tube.

11. The system of claim 1, further comprising a plurality of linear tubes disposed between the first end and the second end, each of the plurality of linear tubes defining at least one aperture therein, with a nozzle disposed through each of the at least one aperture of each of the plurality of linear tubes.

12. The system of claim 11, wherein each of the plurality of linear tubes is arranged proximate to at least one of the plurality of linear tubes, such that the plurality of linear tubes are arranged in a sequential series.

13. The system of claim 11, wherein at least one of the plurality of linear tubes is disposed within another of the plurality of linear tubes.

14. The system of claim 1, wherein each of the plurality of hyperoxic nanobubbles includes a diameter of between 40 nanometers and 300 nanometers.

15. The system of claim 1, wherein the nanobubble generator further comprises a pressure swing adsorption separation system that utilizes an air input and separates oxygen from nitrogen within the air input, thereby generating a high concentration hyperoxic oxygen nanobubble output.

16. The system of claim 1, further comprising a tank including an air mixture, the tank fluidically coupled to the nanobubble generator.

17. The system of claim 16, further comprising a pump intermediately secured to the tank and to the nanobubble generator, the pump configured to receive the air mixture from the tank and transmit the air mixture to the nanobubble generator.

18. The system of claim 16, wherein the tank is disposed on at least one of the first shoreline and the second shoreline.

19. The system of claim 1, wherein the nanobubble generator is stationary within the body of water.

20. The system of claim 1, further comprising a portable screening device disposed on at least one of the first shoreline and the second shoreline, the portable screening device in electronic communication with the nanobubble generator, the portable screening device including a Raman spectroscopy component to detect a presence of a brevetoxin within the body of water.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For a fuller understanding of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which:

(2) FIG. 1 is a perspective view of a hyperoxic nanobubble treatment and remote brevetoxin screening, in accordance with an embodiment of the present invention.

(3) FIG. 2 is a perspective view of a hyperoxic nanobubble treatment and remote brevetoxin screening showing a tank, a pump, and a nanobubble generator, in accordance with an embodiment of the present invention.

(4) FIG. 3 is a perspective isolated view of a nanobubble generator including an approximately consistent diameter throughout a length thereof, in accordance with an embodiment of the present invention.

(5) FIG. 4 is a perspective isolated view of a nanobubble generator including different diameters throughout a length thereof, in accordance with an embodiment of the present invention.

(6) FIG. 5A is a perspective isolated view of a nanobubble generator including a plurality of approximately linear tubes that are adjacent, in accordance with an embodiment of the present invention.

(7) FIG. 5B is a perspective isolated view of a nanobubble generator including a plurality of approximately linear tubes that are spaced apart, in accordance with an embodiment of the present invention.

(8) FIG. 5C is a perspective isolated view of a nanobubble generator including nozzles arranged in a parallel configuration to one another on opposing sides of an approximately linear tube, in accordance with an embodiment of the present invention.

(9) FIG. 6 is a section view of a nanobubble generator, in accordance with an embodiment of the present invention.

(10) FIG. 7 depicts a graphical comparison of untreated and treated water, plotting algae cell counts per liter over time, in accordance with an embodiment of the present invention.

(11) FIG. 8 is a schematic view showing the use of surface enhanced Raman spectra to identify toxins in the presence of a mixture of thiourea and acid, in accordance with an embodiment of the present invention.

(12) FIG. 9A is a graphical representation showing results of brevetoxin Raman spectra, in accordance with an embodiment of the present invention.

(13) FIG. 9B is a graphical representation showing results of brevetoxin Raman spectra, in accordance with an embodiment of the present invention.

(14) FIG. 10 is a graphical representation showing results of brevetoxin Raman spectra, in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

(15) In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings, which form a part thereof, and within which are shown by way of illustration specific embodiments by which the invention may be practiced. It is to be understood that other embodiments may be utilized, and structural changes may be made without departing from the scope of the invention.

(16) As used in this specification and the appended claims, the singular forms a, an, and the include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term or is generally employed in its sense including and/or unless the context clearly dictates otherwise.

(17) The phrases in some embodiments, according to some embodiments, in the embodiments shown, in other embodiments, and the like generally mean the particular feature, structure, or characteristic following the phrase is included in at least one implementation. In addition, such phrases do not necessarily refer to the same embodiments or different embodiments.

(18) All numerical designations, such as measurements, efficacies, physical characteristics, forces, and other designations, including ranges, are approximations which are varied up or down by increments of 1.0 or 0.1, as appropriate. It is to be understood, even if it is not always explicitly stated that all numerical designations are preceded by the term about. As used herein, about or approximately refers to being within an acceptable error range for the particular value as determined by one of ordinary skill in the art, which will depend in part on how the value is measured or determined. As used herein, the term about refers to +15% of the numerical; it should be understood that a numerical including an associated range with a lower boundary of greater than zero must be a non-zero numerical, and the term about should be understood to include only non-zero values in such scenarios.

(19) The present invention includes a hyperoxic nanobubble treatment and remote brevetoxin screening system that is configured for installation within a body of water, such as a narrow cross-section of an area of a body of water. The system is a stationary, high oxygen concentration, gas flow system that injects a large amount of oxygen enriched nanobubbles underwater at a small cross-section of a body of water, thereby controlling a large amount of water rapidly and in an environmentally-safe manner. Embodiments of the system will be described in greater detail in the sections herein below.

(20) As shown in FIG. 1, hyperoxic nanobubble treatment and remote brevetoxin screening system 10 (alternatively referred to as system 10) is configured for installation within body of water 12. System 10 includes first end 14 opposite second end 16; in an embodiment, first end 14 is separated from second end 16 by a length of approximately between 10 m and 1,000 m to define a lateral expanse of system 10, In an embodiment, first end 14 of system 10 is proximate to first shoreline 32 of body of water 12, and second end 16 of system 10 is proximate to second shoreline 34 of body of water 12. As such, embodiments of system 10 are secured to opposing shorelines 32, 34 (such as via a winch and a cable disposed at opposing first and second ends 14, 16 of system 10), thereby allowing system 10 to be installed, removed, and reinstalled within body of water 12. In other embodiments, at least one of first end 14 and second end 16 is disposed on a shoreline; for example, in an embodiment, first end 14 is disposed on first shoreline 32, with second end 16 being disposed within body of water 12. It should be appreciated that embodiments of system 10 can include second end 16 being disposed on second shoreline 34, and can include first end 14 being disposed on first shoreline 32 and second end 16 being disposed on second shoreline 34. In addition, in an embodiment, system 10 is anchored to a floor of body of water 12 to further stabilize system 10, such that system 10 is approximately stationary during a flow of water within body of water 12.

(21) System 10 includes nanobubble generator 20 spanning from first end 14 to second end 16. Nanobubble generator 20 includes linear tube 18 disposed between first end 14 and second end 16, with linear tube 18 defining at least one aperture therein. Nanobubble generator 20 also includes at least one nozzle 22 (alternatively referred to as a plurality of nozzles 22 in embodiments including more than one nozzle 22) that is receivable through the at least one aperture, such that nozzle 22 extends in a direction away from linear tube 18 and extends at least partially into body of water 12. In an embodiment, nozzle 22 includes a lateral expanse of between approximately 5 mm and 500 mm.

(22) In an embodiment, nozzle 22 extends approximately perpendicularly away from linear tube 18 (i.e., an embodiment of nozzle 22 is oriented at an angle of approximately 90 with respect to linear tube 18); however, it should be appreciated that other angles of nozzle 22 with respect to linear tube 18 are contemplated (i.e., angles between approximately 0 and 180 with respect to linear tube 18, including an approximately 45 angle, an approximately 120 angle, and an approximately 135 angle, as well as a parallel configuration of nozzles 22 as shown in particular in FIG. 5C), so long as nozzle 22 extends through an aperture and in a direction away from linear tube 18. Each nozzle 22 is capable of bubble delivery within body of water 12, such as through pressurized dissolution, rotational flow, turbulent static mixing, ejector nozzles, ultrasonic vibrations, oscillation, venturi systems, mixed vapor direct contact condensation, and similar delivery methods. While the embodiment of system 10 shown in FIG. 1 includes linear tube 18 spanning partially between first end 14 and second end 16, it should be appreciated that embodiments of system 10 can include linear tube 18 extending from first end 14 to second end 16.

(23) Nanobubble generator 20 is capable of injecting billions of charged nanoparticles per cubic millimeter, dissolving oxygen with a 90% efficiency; accordingly, nanobubble generator 20 is configured to inject nanobubbles of enriched air into body of water 12. Enriched air is helpful for humans and other animals, but has a negative effect on algae, since high oxygen concentrations reduce algae growth and photosynthesis, ultimately decreasing the number of algae cells in water without directly killing algae cells. As such, system 10, via nanobubble generator 20, injects nanobubbles into body of water 12 to reduce algae growth while maintaining a presence of algae within body of water 12, thereby contributing to a healthier ecosystem by maintaining the helpful presence of an amount of algae within body of water 12.

(24) Exhaled bubbles are different in size and have unique physical and chemical propertieslarger bubbles have a small surface area, rising rapidly within a body of water (such as body of water 12), resulting in low oxygen conversion rate between the gas and liquid phases. However, since nanobubbles are ultrafine bubbles that can stay underwater for weeks, nanobubbles generated via nanobubble generator 20 possess 1000 greater surface area/mL as compared to larger bubbles created without the use of nozzle 22, and are capable of increasing oxygen conversion of the bubbles by 800% as compared to larger bubbles created without the use of nozzle 22 (Li 2014; Meegoda 2018); in an embodiment, nanobubbles generated via nanobubble generator 20 include a diameter of approximately between 40 nm and 300 nm. Research has shown that an average size of 90 nm of bubbles can remain intact for a long period of time (such as between 1-2 weeks), and the bubbles include a large surface area to transfer a large amount of oxygen. A high stagnation time of bubbles underwater within body of water 12 increases physical absorptions and chemical reactions on the surface of the bubbles, ultimately aiding the oxygen transport between the gas and liquid phase. Moreover, nanobubbles can exist for several weeks in an aqueous solution since the electrically charged liquid-gas interface of nanobubbles creates repulsive forces that prevent bubble coalescence.

(25) Enriched air can be produced via nanobubble generator 20 in different ways; in an embodiment, pressure swing adsorption is utilized to produce a large amount of hyperoxic air for system 10. Hyperoxia occurs when organisms, cells, and tissues are exposed to an excess amount of oxygen or a higher-than-normal partial pressure of oxygen. System 10 uses a large amount of oxygen during the proliferation reduction process of algae, with air serving as the gas mixture as the initial gas and oxygen are separated from the nitrogen gas as a product. In an embodiment, system 10 converts air including approximately 78% N.sub.2, 21% O.sub.2, and 1% other gases (such as CO.sub.2) into an O.sub.2 concentration of greater than approximately 90%, and an N.sub.2 and other gas concentration of less than approximately 10%. In another embodiment, system 10 converts an air mixture to include a concentration of O.sub.2 gas of at least 80%.

(26) In an embodiment, pressure swing adsorption is used for the separation within system 10. Pressure swing adsorption utilizes high pressure to trap gases onto solid surfaces as air passes alternatively over a molecular sieve that is designed to adsorb nitrogen. The reusable adsorption bed can be recovered and used continuously; an additional advantage is that a high concentration of oxygen can be generated for use within system 10. However, it should be appreciated that other separation systems can be used within system 10, including membrane separation.

(27) Turning to FIG. 2, embodiments of system 10 include one or more subunits. In an embodiment, pump 24 utilizes air stored within tank 26 to generate a desired gas mix that is pumped into linear tube 18. In an embodiment, pump 24 is disposed on at least one of first shoreline 32 and second shoreline 34. Embodiments of the gas mix include oxygen and nitrogen gases; however, it should be appreciated that other gases can be used alone or in combination, including trace amounts of gases such as argon and carbon dioxide. In an embodiment, a high oxygen concentration is generated including a 100 ultra-high purity O.sub.2 gas directly connected to a gas tank, such as tank 26; it should be appreciated that oxygen can also be concentrated from atmospheric gases. In an embodiment, pump 24 delivers the gas mixture to linear tube 18 at a pressure of approximately between 1 bar and 10 bar, and at a flow rate of approximately between 0.1 liters/minute and 30 liters/minute.

(28) As shown in FIGS. 3-6, different embodiments of nanobubble generator 20 include different orientations of linear tube 18. For example, in an embodiment (as shown in FIG. 3), nanobubble generator 20 includes a single linear tube 18 including a plurality of nozzles 22, with linear tube 18 including an approximately consistent diameter throughout a length of linear tube 18. However, as shown in FIG. 4, an alternative embodiment of nanobubble generator 20 includes first linear tube portion 18a and second linear tube portion 18b, with first linear tube portion 18a having a greater diameter than second linear tube portion 18b (forming a gradient tube). Moreover, as shown in FIG. 5A, an embodiment of nanobubble generator 20 includes a plurality of linear tubes 18a, 18b, 18c, and 18d; while the plurality of linear tube tubes 18a, 18b, 18c, and 18d are shown having an approximately equal diameter and length, it should be appreciated that one or more of the plurality of linear tube tubes 18a, 18b, 18c, and 18d can vary in diameter and/or length as compared to other linear tubes in the plurality of linear tubes 18a, 18b, 18c, and 18d. Similarly, as shown in FIG. 5B, an embodiment of nanobubble generator 20 includes a plurality of linear tubes 18a, 18b, 18c, and 18d that are each spaced apart from and independent from the remaining plurality of linear tubes, with an end of each of the plurality of linear tubes 18a, 18b, 18c, and 18d being disposed on a shoreline (such as first shoreline 32, as shown in FIG. 5B, although it should be appreciated that the plurality of linear tubes 18a, 18b, 18c, and 18d can be at least partially disposed on second shoreline 34). Moreover, as shown in FIG. 5C, nozzles 22 can be arranged parallel to one another in a branching relationship to linear tube 18.

(29) Turning to FIG. 6, embodiments of nanobubble generator 20 include linear tube 18c embedded within linear tube 18b, such that linear tube 18c includes a diameter that is smaller than a diameter of linear tube 18b. Moreover, embodiments of nanobubble generator 20 include linear tube 18b embedded within linear tube 18a, such that linear tube 18b includes a diameter that is smaller than a diameter of linear tube 18a. In an embedded linear tube 18 system, any kind of gas and liquid mixture at any pressure can be delivered. Linear tube(s) 18 may be connected multiple times and the length of any one linear tube 18 can span between approximately 10 m and 30 m. Linear tube(s) 18 may be connected through an isobaric or gradient pressure fashion. For example, in the case of an isobaric tube, the pressure in linear tube 18 is equal at any point. In the case of gradient tubing, the diameters of different portions of linear tube(s) 18 may be modified to create a delivery system to provide the desired pressure of the gas.

(30) As noted above, system 10 is configured for installation within body of water 12. The position of system 10 within body of water 12 is important given that narrow cross-sections of areas of body 12 including enriched air bubbles increase waterflow rates, acting as a funnel for the waterflow (whereas in larger areas of water, the enriched air bubbles intermix at a lower flow rate). As such, system 10 is positioned at narrow water flow ports, such as small passes or water inlets (such as those between the Gulf of Mexico and bay areas) through nanobubble generator 20. Naturally occurring tides in such narrow water flow bodies of water 12 continuously move water therethrough to completely exchange bay water every 5-6 days.

(31) In particular, since system 10 is stationary and does not include propelling units, such as underwater turbines, system 10 is designed to utilize natural tidal movements to generate nanobubbles via nanobubble generator 20. Since high and low tides move a large amount of water within body of water 12 over a small cross-section, an example of body of water 12 includes Sarasota Bay (or a substantially equivalent body of water) which spans an area of approximately 91.1 km.sup.2 at an average depth of 2 m. The average volume of such an example of body of water 12 is approximately 1.82108 m.sup.3. The mean range of tides in such an example of body of water 12 is approximately 0.38 m; as such, a total of 3.5107 m.sup.3 of water can be filtered within body of water 12 during a single tidal cycle, representing approximately 20% of the total volume in body of water 12. Placement of system 10 within such an example of body of water 12 is such that system 10 operates at a small cross-section of a body of water, thereby controlling a large amount of water rapidly and in an environmentally-safe manner.

(32) In addition, in an embodiment, system 10 spans approximately 200 m from first end 14 to second end 16 within body of water 12 having an average depth of approximately 3.6 m, with a high tide water flow rate of approximately 0.27 m/s. Within such an embodiment, system 10 can treat an average volume of approximately 11,664 m.sup.3/min, generating approximately 10010.sup.3 nanobubbles/liter.

(33) In embodiments, system 10 includes portable screening device 30 (as shown in FIG. 1, with portable screening device 30 being disposed on second shoreline 34); in an embodiment, portable screening device 30 utilizes Raman spectroscopy (including a surface enhanced Raman scattering technique, alternative known as SERS). While SERS has been used in other industries to identify items such as pharmaceuticals, pesticides, toxins, and heavy metals, SERS have not been extended for use in the detection of brevetoxins. As such, as shown in FIG. 8, portable screening device 30 includes nanoparticles (such as gold or silver nanoparticles) to create binding sites for brevetoxin samples within portable screening device 30. When portable screening device 30 receives a sample (such as via a strip of hydrophilic paper, such as cotton), any brevetoxin molecules within the sample interact with the nanoparticles within portable screening device 30, generating a strong signal enhancement that is detectable via a laser light emitted from portable screening device 30.

EXPERIMENTAL METHOD

(34) Portable screening device 30 was tested to determine whether brevetoxins could be identified by portable screening device 30 in a field-based setting. Silver colloidal nanoparticles were synthesized, with a final product being a greyish-yellow colloid in methanol, which was deposited on the surface of small paper strips. During the experimental method, one brevetoxin solution was utilized, containing five major brevetoxins (PbTx-1, PbTx-2, PbTx-3, PbTx-CBA, and Brevenal). After the deposition and after a ten-minute drying period, SERS Raman spectra were acquired via portable screening device 30 of the background, the brevetoxins with a low concentration of silver nanoparticles, and the brevetoxins with a high concentration of silver nanoparticles (as shown graphically in FIGS. 9A-9B).

(35) To confirm that the signals detected by portable screening device 30 were produced by the brevetoxins, prior research results were compared to the results shown in FIGS. 9A-9B. For example, ten different characteristic vibrational modes were observable as shown in FIG. 8, including at 715, 1048, 1088, 1209, 1269, 1326, 1376, 1448, 1683, and 1783 cm.sup.1. The ten published vibrational frequencies for brevetoxins are 729, 1058, 1080, 1206, 1262, 1314, 1374, 1454, 1686, and 1790 cm.sup.1, thereby indicating a match between the brevetoxins identified via portable screening device 30 and those known in prior research. In addition, as shown in FIG. 10, brevetoxins were identified via portable screening device 30 at the approximately 150 ppm concentration level.

REFERENCES

(36) Li, H.; Hu, L.; Song, D.; Al-Tabbaa, A. Subsurface Transport Behavior of Micro-Nano Bubbles and Potential Applications for Groundwater Remediation. International Journal of Environmental Research and Public Health. 2014, pp 473-486.

(37) Meegoda, J. N.; Aluthgun Hewage, S.; Batagoda, J. H. Stability of Nanobubbles. Environ. Eng. Sci. 2018, 35 (11), 1216-1227.

(38) All referenced publications are incorporated herein by reference in their entirety. Furthermore, where a definition or use of a term in a reference, which is incorporated by reference herein, is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.

(39) The advantages set forth above, and those made apparent from the foregoing description, are efficiently attained. Since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

(40) It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention that, as a matter of language, might be said to fall therebetween.