FIELD OF THE INVENTION

[0001 ] The present invention relates to a system and a method for growing one or more biological organisms and in particular to a system and a method for utilising carbon dioxide for enhancement of growing one or more biological organisms contained in a liquid.

[0002] The invention has been developed primarily to facilitate the growth of biological organisms such as algae contained in a flow of the liquid and will be described herein with reference to that application. Moreover, in the preferred embodiments, the growth of the algae is, in part, to assist with the absorption of carbon dioxide from the atmosphere or from a supply of waste gasses and for the production of bio-fuels and other products derivable from algae. While some embodiments will be described herein with particular reference to those technical applications, it will be appreciated that the invention is not limited to such a field of use, and is applicable in broader contexts including the growth of other biological organisms, such as bacteria, zooplankton and marine organisms contained in a liquid.

BACKGROUND

[0003] Any discussion of the background art throughout the specification should in no way be considered as an admission that such art is widely known or forms part of common general knowledge in the field.

[0004] Micro and macro algae species inhabit most marine environments, lakes, rivers and surface water reservoirs and, under certain conditions, cause contamination of those water bodies. For example, it is known for an algal species to "bloom" and dominate the flora and fauna of a river or other waterway. During a bloom, the elements present allow the algae to multiply at a very fast rate. Current techniques to grow algae species attempt to replicate these environmental conditions which cause the algae to bloom and rapidly multiply. Examples of current commercial means for growing algae include open race ponds and photo bioreactors.

[0005] Algae species have been grown in open raceway type ponds for the past fifty years using both freshwater species and salt water species. These ponds contain water that is treated with nutrients and carbon dioxide either initially or over time to encourage the growth of the algae. However, due to the low yield and lengthy periods of time to achieve commercial algal densities provided by these existing methodologies there is a need for extremely large ponds which severely limits the sites suitable for the ponds and increases the capital cost of the project. There are also the problems around harvesting of the algae from these large ponds and dealing with the large volumes of water and relatively small quantities of algae.

[0006] In an effort to at least partially address these issues use has been made of bio reactors in which the algae is grown. Whilst there has been possible to achieve for very small scale operations, the capital cost and running costs of these bioreactors are prohibitive and make the commercial application of the technology difficult if not impossible. In any event, such bioreactors also provide only a relatively low yield of algae for a given volume of water.

[0007] Overall, the known systems are often too expensive or otherwise unsuitable to install and operate on a commercial basis, and/or too space intensive to be commercially viable for other than a very small number of sites.

SUMMARY OF THE INVENTION

[0008] It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

[0009] It is an object of the invention, in its preferred form, to provide an improved or alternative system for growing one or more biological organism in a liquid.

[0010] According to a first aspect of the invention there is provided a system for growing one or more forms of biological organisms contained in a liquid, the system including:

a first passage for directing a first flow of the liquid;

a second passage for directing a second flow of the liquid, wherein the second flow is derived at least in part from the first flow and the first flow is derived at least in part from the second flow; and

a third passage for directing a third flow of the liquid, wherein the third flow is derived from the second flow and, in the third passage, at least some of the one or more forms of biological organisms is removed from the liquid.

[0011 ] In an embodiment the system also includes a fourth passage for directing a fourth flow of the liquid, wherein the fourth flow is directed into the first , second and third flow by aspirating jets to create turbulence and the introduction of carbon dioxide in predetermined amounts to increase the growth of the algae and biological organisms within the first and second flow.

[0012] In an embodiment the passages each include an upstream end and a downstream end, and the downstream end of the first passage is connected to the upstream end of the second passage.

[0013] In an embodiment the second flow is derived substantially entirely from the first flow at the downstream end of the first passage.

[0014] In an embodiment the upstream end of the second passage is directly connected to the downstream end of the first passage.

[0015] In an embodiment the downstream end of the second passage is connected to the upstream end of the third passage.

[0016] In an embodiment the third flow is derived substantially entirely from the second flow at the downstream end of the second passage.

[0017] In an embodiment the upstream end of the third passage is directly connected to the downstream end of the second passage.

[0018] In an embodiment the first flow is made to be turbulent in predetermined regions by the injection of the fourth stream carrying carbon dioxide gas and water.

[0019] In an embodiment the first passage includes a first channel having a substantially uniform width and which extends from the upstream end of the first passage.

[0020] In an embodiment the first channel has a substantially uniform depth.

[0021 ] In an embodiment the first passage includes a plurality of successively linked first channels.

[0022] In an embodiment the plurality of successively linked first channels extend from the upstream end to the downstream end of the first passage.

[0023] In an embodiment the second passage includes a second channel having a substantially uniform width and which extends from the upstream end of the second passage.

[0024] In an embodiment the second channel has a substantially uniform depth.

[0025] In an embodiment the second passage includes a plurality of successively linked second channels.

[0026] In an embodiment the third passage includes a third channel that extends from the upstream end of the third passage and a sump that is adjacent to the downstream end of the third passage.

[0027] In an embodiment the third channel has a substantially uniform width.

[0028] In an embodiment the third channel has a substantially uniform depth.

[0029] In an embodiment the third passage includes a plurality of successively linked third channels.

[0030] In an embodiment the fourth passage includes a pressure pipe positioned along the perimeter of first and subsequent channels that extends from the upstream end of the first passage to the downstream end of the final passage which delivers the water from the harvesting sump to a series of jets and aspirators at intervals alone the channels.

[0031 ] In an embodiment the pressure pipe delivers water via a high pressure water pump to the first second and third channels through a venturi jet, which in turn creates a negative pressure in a carbon dioxide manifold delivery system from the carbon dioxide source. The introduction of high pressure water and carbon dioxide gas into the channel creates turbulence and assists in directing the flow of water in the channel.

[0032] In an embodiment the sump is downstream of the or all of the third channels.

[0033] In an embodiment the system includes a flow controller for creating the first flow at or adjacent to the upstream end of the first passage.

[0034] In an embodiment the flow controller, to create the first flow, draws from the third flow.

[0035] In an embodiment the flow controller draws from the third flow at or adjacent to the downstream end of the third passage.

[0036] In an embodiment the flow controller, to create the first flow, draws from the second flow.

[0037] In an embodiment the flow controller draws from the second flow at other than adjacent to the upstream end of the second passage.

[0038] In an embodiment the first passage, between the upstream and downstream ends, defines a first growing zone and the flow controller creates the first flow at the upstream end of the first passage such that the first flow takes a first predetermined period to progress through the first growing zone.

[0039] In an embodiment the second passage, between the upstream and downstream ends, defines a second growing zone and the second flow takes a second predetermined period to progress through the second growing zone.

[0040] In an embodiment the third passage, between the upstream and downstream ends, defines a harvesting zone in which at least some of the one or more forms of biological organisms are removed from the liquid.

[0041 ] In an embodiment, in the harvesting zone, substantially all of the one or more forms of biological organisms are removed from the liquid.

[0042] In an embodiment the system includes a plurality of sensors for providing sensor signals indicative of selected characteristics of one or more of the first, second and third flows.

[0043] In an embodiment the system includes at least one additive station for allowing one or more additives to be introduced into one or more of the first, second and third flows.

[0044] In an embodiment the additives are selected from the group consisting of: a nutrient for at least one of the one or more forms of biological organisms in the respective flow; and a flocculant for aggregating at least one of the one or more forms of biological organisms in the respective flow.

[0045] In an embodiment: the additive introduced into the first flow is selected to be a first nutrient; the additive introduced into the second flow is selected to be a second nutrient; and the additive introduced into the third flow is selected to be a flocculant.

[0046] In an embodiment the flow controller is responsive to the sensor signals for one or more of: creating the first flow; drawing from the second flow; and drawing from the third flow.

[0047] In an embodiment the flow controller is responsive to the sensor signals for controlling one or more characteristics of the additive or additives being introduced into one or more of the first, second or third flow.

[0048] In an embodiment the one or more characteristics include one or more of: the quantity of the given additive; the type of the given additive; the rate of introduction of the given additive; and the timing of the introduction of the given additive.

[0049] According to a second aspect of the invention there is provided a biological organism grown in the system of any one or more of the embodiments described above.

[0050] According to a third aspect of the invention there is provided a product derived from the biological organism of the second aspect.

[0051 ] According to a fourth aspect of the invention there is provided an algal species grown in the system of any one or more of the embodiments of the first aspect of the invention described above.

[0052] According to a fifth aspect of the invention there is provided an algal cake derived from the algal species of the fourth aspect of the invention.

[0053] According to a sixth aspect of the invention there is provided an oil extracted from the algal species of the fourth aspect of the invention.

[0054] According to a seventh aspect of the invention there is provided a method for growing one or more forms of biological organisms contained in a liquid, the method including the steps of:

directing a first flow of the liquid;

directing a second flow of the liquid, wherein the second flow is derived at least in part from the first flow and the first flow is derived at least in part from the second flow; and directing a third flow of the liquid, wherein the third flow is derived from the second flow and, in the third flow, at least some of the one or more forms of biological organisms is removed from the liquid.

[0055] In an embodiment the method also includes the step of directing the fourth flow to deliver the desired amount of carbon dioxide to the first and second flow of the water.

BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Preferred embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a schematic plan view of a system for growing algae in a liquid according to one embodiment of the present invention;

Figure 2 is an enlarged schematic cross sectional side view of the third passage of Figure 1 near the downstream end of that passage;

Figure 3 is a reproduction of the schematic plan view of the system of Figure 1 illustrating the sensor network;

Figure 4 is a reproduction of the schematic plan view of the system of Figures 1 and 3 illustrating the additive outlets;

Figure 5 is a perspective view of a barrier used in the embodiment of Figure 1 ;

Figure 6 is an end view of another barrier used in other embodiments;

Figure 7 is a schematic plan view of an alternative system for growing algae;

Figure 8 is an enlarged view of the adjacent upstream and downstream ends of the system of

Figure 7;

Figure 9 is a schematic top view of a further system for growing microorganisms;

Figure 10 is a schematic plan view of a system for growing algae in a liquid according to another embodiment of the present invention

Figure 1 1 is a reproduction of the schematic plan view of the system of Figure 10 illustrating a liquid and gas distribution system ;

Figure 12 is a perspective view of an exemplary venturi tee for sparging carbon dioxide into the channels;

Figure 13 is a perspective view of a venturi jet; and

Figure 14 is a schematic side view of a venturi jet illustrating the principle of operation of the jet. DETAILED DESCRIPTION

[0057] It will be appreciated whilst the drawings are illustrative of the underlying principles of operation of the embodiments those drawings are not to scale unless expressly stated.

[0058] Referring to Figure 1 there is provided a system 1 for growing one or more forms of biological organisms in the form of green algae. The algae are contained in a liquid which, in this embodiment, is water. System 1 includes a first passage, in the form of four successively linked alternately directed substantially parallel and coextensive open channels 3, 4, 5 and 6, for directing a first flow 8 (represented by a broken line) of the liquid. A second passage, in the form of four successively linked alternately directed substantially parallel and coextensive open channels 1 1 , 12, 13 and 14, directs a second flow 15 of the liquid (also represented with a broken line). The second flow 15 is derived at least in part from the first flow 8 and the first flow 8 is derived at least in part from the second flow 15. A third passage, in the form of three successively linked alternately directed substantially parallel and coextensive open channels 22, 23 and 24, directs a third flow 25 of the liquid (represented as a broken line). The third flow is derived from the second flow 15 and, in the third passage, at least some of the algae are removed from the liquid.

[0059] The water used in system 1 is fresh surface water and requires no specific treatment prior to use. In other embodiments a pre-treatment is provided to remove any high concentrations of contaminants that are present and which, if left, would be detrimental to the growth of the algae in the water. In further embodiments use is made of saline ground water, or a combination of the above.

[0060] System 1 is suitable for growing a wide range of algae, although the selection of that algae will be based upon many factors such as the location of system 1 , the use or not of any coverings for the passages, the water type and temperature, and other factors that will be appreciated by those skilled in the art. It has been found by the present inventor that green algae selected from the division of Chlorophita are well suited to use in system 1 in the low to mid-latitudes and near a coastal area. Species of this division that have been found to be particularly suited include Chlorella Vulgaris and Nannochloropsis Occulata.

[0061 ] The first, second and third passages include respective upstream ends 31 , 33 and 35 and respective downstream ends 36, 38 and 40. The downstream end 36 of the first passage is connected directly to the upstream end 33 of the second passage. That is, flow 8 at end 36 converts, in its entirety, into flow 15 at end 33. In other embodiments, flow 15 at end 33 includes only a portion of flow 8. Whilst in further embodiments, flow 15 includes all of flow 8 plus some or all of one or more other flows. In still further embodiments, end 36 is spaced apart from end 33 and flow 8 is conveyed from end 36 to end 33 via one or more intermediate pipes, channels, conduits or other flow directing devices (none of which are explicitly illustrated).

[0062] The downstream end 38 of the second passage is connected directly to the upstream end 35 of the third passage. That is, flow 15 at end 38 converts, in its entirety, into flow 25 at end 35. In other embodiments, flow 25 at end 35 includes only a portion of flow 15. Whilst in further embodiments, flow 25 includes all of flow 15 plus some or all of one or more other flows. In still further embodiments, end 38 is spaced apart from end 35 and flow 15 is conveyed from end 38 to end 35 via one or more intermediate pipes, channels, conduits or other flow directing devices (none of which are explicitly illustrated).

[0063] All the channels are contained within the bounds of a pond system 45 and define a single continuous body of water and algae that moves progressively along the sequential flows that are described above. In this embodiment the pond system 45 includes four substantially impermeable and linked peripheral concrete walls 46, 47, 48 and 49. Also included are ten longitudinally extending and equally transversely spaced apart interdigitated substantially parallel concrete internal walls 50 that extend alternately from one of walls 48 and 49 and toward the other. The transverse distance between adjacent walls 50 defines the width of the channels. In this embodiment the transverse distance between all adjacent walls 50 is about 5 metres. In other embodiments different transverse spacing between the walls is used. In still further embodiments use is made of different spacing between different pairs of adjacent walls 50.

[0064] The longitudinal spacing between walls 48 and 49 is about 200 metres, although in other embodiments different spacing is utilised. In a further specific embodiment, the longitudinal spacing between the walls is 250 metres. Whilst in further embodiments, other longitudinal spacing includes 100 metres, 120 metres, 150 metres, 180 metres, 220 metres, 280 metres and 300 metres. It will be appreciated by those skilled in the art, with the benefit of the teaching herein, that other longitudinal spacing is also available.

[0065] The number of channels used in each of the passages is able, in other embodiments, to be selected differently. For example, the available land may necessitate different numbers of channels, or differently configured channels. It will also be appreciated that in other embodiments the channels need not be interdigitated or parallel.

[0066] With the exception of the downstream end of channel 24, the channels each include a substantially planar base or floor, and spaced apart and opposed upwardly extending parallel sidewalls that have a substantially uniform height of about 800 mm. The depth of the liquid contained within those channels at any given time is a substantially constant 500 mm. The channels provide a very gentle gradient between end 33 and end 40 to slightly bias the movement of the liquid along the flow paths illustrated. In other embodiments the channels are constructed to be substantially level - that is, the bases of the channels are substantially horizontal and the progress along the illustrated flow paths is affected substantially entirely by the selective ingress and egress of liquid from pond system 45 at selected points. This selective ingress and egress will be described in more detail below.

[0067] Channels 3, 4, 5 and 6 define a first growing zone 55 for the algae, whilst channels 1 1 , 12, 13 and 14 define a second growing zone 56 for the algae. Channels 22, 23 and 24 define a harvesting zone 57 for the algae. It will be appreciated that the zones are sequentially and successively arranged.

[0068] Channels 1 1 , 12, 13 and 14 - that is, the channels in the second growing zone 56 - are lined with a reflective material in the form of with a reflective material in the form of a metallised Mylar® material to increase the amount of sunlight passing through and being reflected back into the second flow 15. For in zone 56 the algae at the top surface of the water in the channels is increasingly absorbing the light and reducing the amount of light energy that is penetrating further into the water. Accordingly, for the light that does enter from above and which impinges upon the sidewalls and base, it is advantageous to have it redirected back into the water and the algae.

[0069] Other embodiments make use of other reflective materials such as a white PVC plastic membrane or the like. In further embodiments, use is made of a combination of those materials.

[0070] In other embodiments less than all of channels 1 1 , 12, 13 and 14 are lined with a reflective material. In further embodiments, one or more of the other channels are also lined with such a material.

[0071 ] For the present embodiment, the volume of liquid contained in each of zones 55 and 56 is about 2 mega-litres - that is, each contains about 2,000,000 litres. Whereas the volume of liquid contained within zone 57 is about 1 .6 mega-litres - that is, about 1 ,600,000 litres.

[0072] As best shown in Figure 2, channel 24 includes a substantially planar and horizontal base 60 that extends from wall 49 to a sump 61 . Sump 61 is adjacent end 40 and includes a substantially planar base 62 having two opposite upstream and downstream edges 63 and 64. An upstream sidewall 65 extends upwardly from edge 63 of base 62 and terminates in a downstream edge 66 of base 60. A downstream sidewall 67 extends upwardly from edge 64 of base 62 and terminates at end 40.

[0073] In other embodiments sump 61 is shaped other than as specifically illustrated in the drawings. For example, in another embodiment, base 62 of sump 61 is other than substantially planar. In further embodiments, sump 61 is spaced apart from channel 24 and the liquid in the flow is separately transported to the sump. In still further embodiments, the sidewalls 65 and 67 are more steeply inclined to create a more sudden drop in pressure in flow 25 as it passes into the sump.

[0074] Base 62 of sump 61 extends across substantially all of the width of passage 24 is about three metres below base 60 and extends upstream of end 41 about ten metres. In other embodiments different dimensions are used.

[0075] System 1 includes a flow controller in the form of a pump, pipe and control system for, amongst other things, creating the first flow 8 at the upstream end 31 of the first passage. The flow controller includes a first centrifugal pump 71 disposed adjacent to end 40 that draws liquid from sump 61 via a flared inlet 72 - that is submerged just below the level of the fluid in sump 61 - and an intermediate pipe 73. Pump 71 conveys the drawn liquid via a perimeter pipe 74 to an outlet 75 that is adjacent to end 31 . Upon exiting the outlet, the liquid forms part of flow 8. That is, the flow controller, and more specifically pump 71 , to create the first flow 8, draws from the third flow 25.

[0076] Inlet 72 is disposed adjacent to end 40 such that pump 71 draws from the third flow 25 adjacent to end 40 of the third passage. In other embodiments, the inlet is disposed elsewhere in the third passage. In further embodiments, pump 71 draws from a number of spaced apart inlets in the third passage.

[0077] The flow controller includes a second centrifugal pump 81 disposed adjacent to wall 48 and within channel 1 1 for drawing liquid from zone 56 via a flared inlet 82 - that is submerged just below the level of the fluid in channel 1 1 - and an intermediate pipe 83. Pump 81 conveys the drawn liquid via a perimeter pipe 84 to an outlet 85 that is adjacent to end 31 and outlet 75. Upon exiting outlet 85, the liquid also forms part of flow 8 together with the liquid from outlet 75. That is, the flow controller, to create the first flow 8, draws from the second flow 15 and the third flow 25.

[0078] Inlet 82 is located intermediate ends 33 and 38 and, more particularly, downstream of end 33 by about one quarter of the flow path length between ends 33 and 38. In other embodiments, inlet 82 is located elsewhere within zone 56. The positioning is typically selected based upon factors such as the rate at which the liquid is drawn into inlet 82, the proportion of flow 8 that is provided by outlet 85, the type of algae being cultivated within system 1 , the concentration of that algae at inlet 82, and others. Preferentially, inlet 82 is located to draw from the second flow 15 at other than adjacent to end 33.

[0079] The flow controller includes a central computer controller 91 that provides control signals to pumps 71 and 81 to regulate the operation of those pumps. This regulation encompasses the timing of actuation and deactivation of the pumps, and the rate at which the pumps respectively draw fluid from the corresponding inlets when activated. In other embodiments less or more operational factors for the pumps are regulated by controller 91 .

[0080] Controller 91 is part of a computer network that allows communication to the elements within that network, and communication to elements external to the network. This allows for remote control and monitoring of system 1 . Parts of this network include communications links in the form of network communications cables 92 and 93 that link pumps 71 and 81 to controller 91 to allow communications between these components. In other embodiments use is made of additional or alternative communications links such as wireless links.

[0081 ] In other embodiments, each of pumps 71 and 81 include dual pumps (not shown) that are independently operated by controller 91 to provide an overall required rate of liquid being delivered to end 31 from outlets 75 and 85. In further embodiments, either or both of pumps 71 and 81 are other than centrifugal pumps.

[0082] In further embodiments, controller 91 is omitted and pumps 71 and 81 are set to operate continuously at a predetermined rate of flow. More particularly, that rate of flow for pump 71 is three times the rate of flow for pump 81 . For a system of the size of system 1 , it has been found that having a continuous rate of flow for pump 71 at about 75,000 litres per hour and a continuous rate of flow for pump 81 at about 25,000 litres per hour allows for continuous operation of the system. This is on the basic assumption that the algae used in the system is selected to be suitable for growth in the geographic location of the system. In more hostile environments it is also possible to erect a canopy or other shelter above the ponds to make the immediate environment of the pond more suitable to the growth of the algae contained within the liquid.

[0083] In other embodiments, the rates of flow from pumps 71 and 81 are in a different proportion that the 3:1 ratio mentioned above. Other usable ratios include 2:1 , 4:1 , 5:1 , 6:1 , 7:1 , 8:1 , 9:1 , 10:1 and 1 1 :1 . The ratio for use in a given installation is selected based upon the concentration of algae required at end 31 to provide sufficient yield at end 40. That in turn will be dependent upon environmental factors (and hence the time of year etc), the size of the passages, the dwell time of the liquid within the passages, the type of algae, the rate of growth of the algae (which is also dependent upon the nutrient loading and content of the liquid), and many other factors as will be apparent to those skilled in the art and having the benefit of the teaching herein.

[0084] The first flow 8 is created by combining the liquid entering end 31 from outlets 75 and 85. In this embodiment that equates to about 100,000 litres of liquid per hour. This rate of introduction of fluid at end 31 is selected such that the dwell time of that liquid within the first passage is a predetermined period. Given that the volume of liquid in the first passage - that is, the combined volume of liquid within channels 3, 4, 5 and 6 - is about 2,000,000 litres, the dwell time of the liquid within the first passage is about 20 hours. This first passage, between the ends 31 and 36, defines the first growing zone 55 in which the algae are maintained within flow 8, which is relatively steady and constant.

[0085] The second passage, between ends 33 and 38, defines the second growing zone 56. In the first part of this passage - that is, in channel 1 1 - the rate of flow 15 is the same as the rate of flow 8, and the dwell time within channel 1 1 is about five hours. At the downstream end of channel 1 1 , pump 81 removes about 25,000 litres per hour from flow 15. Accordingly, flow 15 includes, at the upstream end of channel 12, about 75,000 litres an hour. Accordingly, the dwell time of flow 15 in each of channels 12, 13 and 14 is about six hours and forty minutes. Accordingly, the dwell time of the liquid within zone 56 is about twenty five hours in total.

[0086] In other embodiments different dwell times are used within either or both of zones 55 and 56. Moreover, in further embodiments inlet 82 is placed elsewhere within zone 56.

[0087] The third passage, between ends 35 and 40, defines the harvesting zone 57 in which at least some of the algae is removed from the liquid. In this embodiment, substantially all of the algae are removed from the fluid by drawing it from sump 61 , and this will be described in more detail below. The liquid drawn into inlet 72 by pump 71 has a very low algal content.

[0088] Reference is now made to Figure 3, which is a reproduction of Figure 1 but omitting some features of Figure 1 to allow the clearer illustration of additional features, those additional features being omitted from Figure 1 for the converse reason. It will be appreciated that Figures 1 and 3 are composite Figures that should be taken together to more fully describe system 1 and are separated out for the purpose of clarity of description. It will also be appreciated that corresponding features are denoted by corresponding reference numerals.

[0089] As best shown in Figure 3, system 1 includes a plurality of sensors in the form of eleven arrays 101 of sensors 102 (not all numbered for the sake of clarity) that extend along respective channels 3, 4, 5, 6, 1 1 , 12, 13, 14, 22, 23 and 24. The arrays 101 of sensors 102 are connected via a communications network for providing sensor signals indicative of selected characteristics of one or more of the first, second and third flows. In the embodiment, sensors 102 are disposed on the base of the channels and provide respective first signals indicative of the intensity of visible light impinging upon those sensors. Those first signals are packaged and relayed via the network to controller 91 . In particular, the network includes two wireless stations 103 and 104 for allowing wireless communication across the network. Controller uses the first signals as an indicator of the density of the algae within the water at the different locations along the flow paths and, hence, as one input into determining the rate of flow of the water into end 31 , and the rate of withdrawal of water from the flow at inlet 82.

[0090] In other embodiments different or additional sensor types and locations are used. For example, other sensors include one or more flow sensors at different locations along the flow paths to provide signals indicative of the rate of flow of the liquid, one or more nutrient sensors to provide an indication of the nutrient load in the flow at one or more locations, one or more oxygen sensors or C0 ₂ sensors, and others.

[0091 ] Reference is now made to Figure 4, which is a reproduction of Figures 1 and 3 but omitting some features of Figures 1 and 3 to allow the clearer illustration of additional features, where those additional features were omitted from Figures 1 and 3 for the converse reason. It will be appreciated that Figures 1 , 3 and 4 are composite Figures that should be taken together to more fully describe system 1 and are separated out for the purpose of clarity of description. It will also be appreciated that corresponding features are denoted by corresponding reference numerals.

[0092] System 1 includes at four spaced apart additive stations in the form of a first nutrient station 1 1 1 , a second nutrient station 1 12, a first flocculant station 1 13 and a second flocculant station 1 14. These stations allow additives to be selectively introduced into the first, second and third flows.

[0093] Station 1 1 1 includes a reservoir (not shown) of nutrient, a peristaltic pump (not shown) for drawing predetermined doses of the nutrient from the reservoir at predetermined time intervals, and an outlet 1 15 for directing the doses into the first flow at end 31 . In this embodiment, where the algae population has a density of at least about 10 grams per litre the nutrient is a balanced NPK fertiliser having a concentration of 5,000 parts per million. The dosage of the nutrient is about 0.83 litres/minute given the first flow at the downstream end of channel 6 is about 100,000 litres of liquid per hour. It will be appreciated that in other embodiments different nutrients and dosages of nutrients are used to optimise the growing conditions and costs associated with system 1 .

[0094] Station 1 1 1 is linked to controller 91 via cables 92 to allow communications between the two. This includes the communications of control signals from controller 91 to station 1 1 1 , and the communication of sensor or other data signals from station 1 1 1 to controller 91 . These communications, as with all the communications on the network, are formatted in accordance with one or more communications protocols that are in use on that network.

[0095] Station 1 1 1 is responsive to the control signals for adjusting the dosage of the nutrient or the type of the nutrient that is being added to the first flow. For example, in some embodiments, station 1 1 1 has a plurality of reservoirs for housing different nutrients, and station 1 1 1 is responsive to the control signals from controller 91 to select which of the nutrients is to be added, and at what rate.

[0096] Station 1 12 includes a reservoir (not shown) of nutrient, a peristaltic pump (not shown) for drawing predetermined doses of the nutrient from the reservoir at predetermined time intervals, and an outlet 1 16 for directing the doses into the second flow at the downstream end of channel 12. In this embodiment, where the algae population typically has a concentration of greater than 10 grams per litre, the nutrient is a nitrogen enhanced NPK fertiliser having a concentration which is same as provided by station 1 1 1 . However, the dosage of the nutrient is about 0.6 litres/minute given the second flow at the downstream end of channel 12 is about 75,000 litres of liquid per hour.

[0097] In other embodiments the nutrient added at station 1 1 1 is different to the nutrient added at station 1 12. [0098] Station 1 12 is also linked to controller 91 via cables 92 to allow communications between the two. As with station 1 1 1 , this includes the communications of control signals from controller 91 to station 1 12, and the communication of sensor or other data signals from station 1 12 to controller 91 . Station 1 12 is responsive to the control signals for adjusting the dosage of the nutrient or the type of the nutrient that is being added to the second flow. For example, in some embodiments, station 1 12 has a plurality of reservoirs for housing different nutrients, and station 1 12 is responsive to the control signals from controller 91 to select which of the nutrients is to be added, and at what rate.

[0099] Station 1 13 includes a reservoir (not shown) of flocculant, a peristaltic pump (not shown) for drawing predetermined doses of the flocculant from the reservoir at predetermined time intervals, and an outlet 1 17 for directing the doses into the third flow at the upstream end of channel 23. In this embodiment, the flocculant is an organic coagulant having a concentration of 50 parts per million. Moreover, the dosage of the flocculant is about 0.062 litres/minute given the third flow is about 75,000 litres of liquid per hour.

[00100] Station 1 13 is linked to controller 91 via cables 92 to allow communications between the two. This includes the communications of control signals from controller 91 to station 1 13, and the communication of sensor or other data signals from station 1 13 to controller 91 .

[00101 ] Station 1 13 is responsive to the control signals for adjusting the dosage of the flocculant or the type of the flocculant that is being added to the third flow. For example, in some embodiments, station 1 13 has a plurality of reservoirs for housing different flocculants, and station 1 13 is responsive to the control signals from controller 91 to select which of the flocculants is to be added, and at what rate.

[00102] Station 1 14 includes a reservoir (not shown) of flocculant, a peristaltic pump (not shown) for drawing predetermined doses of the flocculant from the reservoir at predetermined time intervals, and an outlet 1 18 for directing the doses into the third flow at the upstream end of channel 24. In this embodiment, the algae has a harvestable density in the third zone and the flocculant is an organic coagulant having a concentration of 25 parts per million which is different to that provided by station 1 13. Moreover, the dosage of the organic coagulant is about 0.031 litres/minute, which is also different to that provided by station 1 13.

[00103] In other embodiments stations 1 13 and 1 14 add different flocculants or different dosages of flocculants that those specified above. In further embodiments, the type, concentration and dosage of the flocculant at stations 1 13 and 1 14 is substantially identical.

[00104] Station 1 14 is also linked to controller 91 via cables 92 to allow communications between the two. As with station 1 13, this includes the communications of control signals from controller 91 to station 1 14, and the communication of sensor or other data signals from station 1 14 to controller 91 . Station 1 14 is responsive to the control signals for adjusting the dosage of the flocculant or the type of the flocculant that is being added to the third flow. For example, in some embodiments, station 1 14 has a plurality of reservoirs for housing different flocculant, and station 1 14 is responsive to the control signals from controller 91 to select which of the flocculants is to be added, and at what rate.

[00105] In further embodiments, the flocculant added to the third flow at one or both of stations 1 13 and 1 14 includes a combination of different flocculants.

[00106] In further embodiments, stations 1 1 1 , 1 12, 1 13 and 1 14 include more than one peristaltic pump. In further embodiments, one or more of the stations includes another form of pump in addition to or instead of one or more peristaltic pumps.

[00107] In other embodiments, one or more of stations 1 1 1 , 1 12, 1 13 and 1 14 are located other than as illustrated in the described embodiments. In further embodiments, use is made of a different number of such stations.

[00108] It will be appreciated that the addition of one or more nutrients to the flows is to contribute to optimal growth conditions for the algae in the flow. Accordingly, for different algae, climatic conditions, prevailing weather conditions, etc. the type and dosage of the nutrient varies. In some embodiments the dosage of the nutrients is regularly recalibrated by controller 91 in response to one or more of the above factors, and/or other factors. However, in other embodiments a standard dosage is determined for the given location and added uniformly.

[00109] The addition of the flocculant at stations 1 13 and 1 14 is to aggregate at least one of the one or more forms of biological organisms in the third flow. The aggregated organisms will continue to move within the flow and into sump 61 for collection. Due to the aggregation, the organisms will progressively settle toward base 62 of sump 61 where they will be available for ease of collection. The dosage of the flocculant is such that substantially all the algae (or other organisms being grown) will aggregate and move toward base 62. Accordingly, the water or other liquid drawn into inlet 72 will be substantially algae free, or will at least have a low algal concentration.

[00110] In use, controller 91 is responsive to the various sensor signals described for the first flow; drawing from the second flow; and drawing from the third flow. The selective drawing of the liquid from the different locations provides for a substantially closed system once system 1 is operational. That is, in zone 1 the first flow includes both the water drawn from the third flow - which is substantially free of algae - and water drawn from the second flow - which has a relatively high concentration of algae. The combination of the two, together with the nutrient from station 1 1 1 , provides a favourable environment for the growth of the algae in the first flow.

[00111 ] It will be appreciated by those skilled in the art, having considered the disclosure in this specification, that there will be a need to provide additional water (or other liquid) to the flow to compensation for liquid losses in system 1 . Those losses are relatively minor typically and include losses due to evaporation to atmosphere, through seeping from the channels, and any spillage or leakage from the various pipes used to move the water from one part of the system to another. In other embodiments where one or more the channels are lined, the lining is selected to be of a water impermeable material to further limit the losses through seepage.

[00112] In some embodiments the bases and sidewalls of the channels are at least in part constructed from concrete. In other embodiments, the bases are constructed from concrete and the walls from plastics or composite materials. In other embodiments both the bases and sidewalls are constructed from composite materials. In further embodiments, the bases of the channels include compacted earth, whilst in still further embodiments, the bases of the channels include compacted particulate material.

[00113] It will also be appreciated that the first, second and third flows are relatively gentle and the upper surface of the water is not overly disturbed or aerated. This allows for movement of the water whilst still providing good growing conditions within that water for the algae in the first and second flows, and for gradual movement of the aggregated algae in the third flow to sump 61 .

[00114] Also included in the channels in zones 55 and 56 are a plurality of spaced apart barriers for providing sub-surface turbulence. An example of such a barrier is illustrated in Figure 5 and designated with reference numeral 125. More particularly, barrier 125 includes a generally rectangular laterally elongate lower surface 126 that, in use, is abutted to the base of the channel in which the barrier is placed. Barrier 125 extends between a first end 127 and a second end 128 and has a substantially uniform cross section. The barrier includes an upstream segmented surface that is collectively defined by a substantially vertical side face 129 and a substantially horizontal top face 130 that intersect at a common leading edge 131 . Face 130 also intersects with a trailing substantially vertical face 133 at a common edge 134 that is substantially parallel with edge 131 . The spacing between ends 127 and 128 is about 100 mm less than the width of channels in which the barrier is to be placed. In other embodiments, the spacing between those ends is much less than the width of the relevant channel, whilst in others it is substantially the same.

[00115] In use, barrier 125 extends laterally across a channel and normal to the flow and is secured to the adjacent base. Ends 127 and 129 are opposed with and substantially parallel with the adjacent sidewalls of the channel. The barrier is about 50 mm high and extends about 100 mm in the direction of the flow. A plurality of like barriers is disposed within the channel at equal intervals of about 1 metre. In other embodiments different spacing and barrier dimensions are used. Moreover, in some embodiments, one or more of the barriers are disposed at other than normal to the flow.

[00116] The placement of the barriers within the channel creates a light agitation within the flow due to the turbulence arising from the discontinuities introduced to the otherwise substantially planar base. This agitation allows for some movement of the algae to: encourage a relatively homogenous content within the flow in a given channel; reduce the risk of unwanted localised concentrations of nutrients. Importantly, whilst the agitation is sufficient to give rise to gradual and incremental change, it is not so vigorous as to break the surface of the water and aerate that water.

[00117] Reference is now made to Figure 6 where there is illustrated an alternative barrier 137, where corresponding features are denoted by corresponding reference numerals. In particular, barrier 137 includes a substantially uniform generally triangular cross section rather than the substantially uniform generally rectangular cross section of barrier 125. Barrier 137 includes only inclined upstream face 129 and inclined downstream face 133 that intersect at a common edge 138.

[00118] In other embodiments barriers having different cross sectional shapes are use. Moreover, the cross section of the barriers need not be uniform.

[00119] A further embodiment of a system for growing one or more forms of biological organisms is illustrated in Figure 6, where corresponding features are denoted by corresponding reference numerals. More particularly, system 140 is similar to system 1 and many of the like features from Figures 1 , 2, 3 and 4 have been omitted for the sake of clarity. System 140 includes a different configuration for channel 24 and a consequential different configuration of walls 46 to 49. There is also included an additional concrete wall 141 that defines one sidewall of channel 24 and one end of each of the other channels. Wall 141 includes adjacent to one end a first opening 143 for allowing relatively unimpeded passage of flow 25 between channels 23 and 24. As best shown in Figure 8, wall 141 includes at its other end, adjacent end 40 of channel 24, a second opening (not explicitly shown) that lies wholly but just below the water level in channel 24. Extending through this second opening is pipe 73. In this embodiment, pump 71 is substituted with a submersible propeller pump 145. As pump 145 is not required to lift the water that is being transferred from end 40 of channel 24 to end 31 of channel 3, its energy usage is lessened relative to that of pump 71 .

[00120] The above embodiments allow the performance of a method for growing one or more forms of biological organisms contained in a liquid. This method includes the steps of: directing the first flow of the liquid; directing the second flow of the liquid, wherein the second flow is derived at least in part from the first flow and the first flow is derived at least in part from the second flow; and directing the third flow of the liquid, wherein the third flow is derived from the second flow and, in the third flow, at least some of the one or more forms of biological organisms is removed from the liquid.

[00121 ] Reference is now made to Figure 9 where corresponding features are denoted by corresponding reference numerals. In particular, there is illustrated a system 150 for growing one or more biological organisms. This system includes sixteen systems 1 arranged in a 4 x 4 array on a site 151 that is relatively flat, has good access to water supplies and is in a mild environment best suited to growing algae. Each of systems 1 is able to operate independently, or to be centrally controlled. Accordingly, in some embodiments, the owner of site 151 is also the operator of each and all of systems 1 . However, in other embodiments, the owner of site 151 is different to one or more of the operators of the respective systems 1 .

[00122] Although system 150 is shown as having sixteen systems 1 , in other embodiments a different number of systems 1 are used.

[00123] The close location of the array of systems 1 facilitates the provision of electrical power for each system , as well as simplifying the stock of spare parts, nutrients and other consumables used during the normal operation of systems 1 . In this particular embodiment, site 151 includes a site office 152 in which is located a computer system (not shown) that performs centrally the operation of controller 91 for all systems 1 . Also separately located within office 152 are reserves of nutrients, spare parts for pumps, pipes and fitting and other hardware, and replacement equipment so that any breakdowns or failures are able to be quickly resolved.

[00124] The growth of the algae in all systems 1 is centrally managed and monitored by the operator of site 151 . This operator also manages the harvesting of the algae from the separate systems 1 , and the harvested algae are taken to office 152 for weighing, packaging and identification. The packaged algae are then transported to an algae processing factory 155. In this embodiment, factory 155 is close to site 151 and processes the algae to derived both oil and algal cake. [00125] Referring now to Figure 10, there is illustrated a further embodiment system 160 for growing one or more forms of biological organisms. System 160 includes a pond system 162 having the majority of the features described in relation to system 45. Corresponding features of system 45 are designated with the same reference numerals in system 162. The primary differences between system 45 and system 162 are described below.

[00126] System 162 includes a further open channel 26 for directing a fourth flow 164 of the liquid. Channel 26 is linked to channel 24 at end 40 and is alternately directed substantially parallel and coextensive to channel 24. Channel 26 is defined by external walls 46, 48 and 49, and a longitudinally extending concrete internal wall 50 that is equally transversely spaced apart and substantially parallel to other internal walls 50. The fourth flow 164 is derived at least in part from the third flow 25 of the liquid.

[00127] Channel 26 includes a downstream end 166 that is linked with a substantially longitudinal open channel 27 that extends substantially 90 ^s to channels 3, 4, 5, 6, 1 1 , 12, 13, 14, 22, 23 and 24 for returning fourth flow 164 to end 31 of channel 3 and providing a substantially continuous flow of the liquid through system 162. Channel 27 is defined by external walls 46, 47 and 49, as well as an internal wall 167, which extends substantially parallel with wall 49 and connects with ends of each internal wall 50 Channel 27 includes a sump 168 at a downstream end 170 adjacent end 31 of channel 3. Sump 168 is similar in shape and profile to that of sump 61 illustrated in Figure 2.

[00128] Sump 168 is positioned to collect algae after a flocculation process of the liquid (through the controlled addition of flocculants) in a similar manner as that described above in relation to system 45. In system 162, flocculant station 1 14 is located in channel 27. A pump 172 having an inlet draws at least some of the liquid via a flared inlet 174 from channel 27 through an extracting pipe 176 to harvest the algae within the liquid. The clarified liquid at sump 168 in channel 27 passes from channel 27 to channel 3 to continue the dynamic flow through pond system 162 and the precipitated algae are removed from sump 168 for external processing.

[00129] The volume of liquid contained within zone 57, including channels 26 and 27 is about 2.2 mega-litres - that is, about 2,200,000 litres.

[00130] The systems for growing one or more forms of biological organisms described herein have the capability to sequester and utilise large amounts of carbon dioxide gas. Figure 1 1 illustrates a reproduction of Figure 10 but omitting some features of Figure 10 to allow the clearer illustration of additional features in the form of a liquid and gas distribution system for injecting liquid and carbon dioxide gas into the various systems. It will be appreciated that Figures 1 and 1 1 are composite Figures that should be taken together to more fully describe the systems and are separated out for the purpose of clarity of description. It will also be appreciated that corresponding features are denoted by corresponding reference numerals. While Figure 1 1 illustrates system 160, it will be appreciated that an equivalent liquid and gas distribution manifold system is able to be applied to system 1 .

[00131 ] The distribution manifold system includes a carbon dioxide delivery pipe 178 that is connected to a supply of flue gas or raw carbon dioxide from a source 180 some distance from system 160. Pipe 178 traverses system 160 substantially parallel to and approximately midway between external walls 48 and 49. Pipe 178 distributes the gas into smaller 300 mm diameter pipes 182, which extend along each channel and are attached to the top of each of walls 50 through a series of tee joints (not shown). In other embodiments, pipes 182 are maintained in position along each channel by supporting cables or wires. Pipes 182 include a plurality of spatially separated gas jets (not shown) that distribute the gas to the liquid along each channel. The manifold system supplies the carbon dioxide gas in an even distribution to the total growing area of the system.

[00132] The manifold system also includes a liquid delivery pipe 184 disposed adjacent and below delivery pipe 178 across and along the dividing walls within the channels. This second manifold is for the delivery of high pressure liquid to a series of venturi jets (not shown) positioned along each channel. Three schematic illustrations of exemplary venturi jet devices are shown in Figures 12 to 14.

[00133] The venturi jets are positioned about 50 mm below the surface of the liquid in the channels and are pointed in a direction congruent with the flow of the liquid within each channel. The high liquid pressure delivery to the venturi jets causes a pressure drop as the liquid exits the venturi jets into the ambient pressure of the liquid in the channel, this liquid pressure drop causes a negative pressure or vacuum as the liquid passes through the venturi jets. In some embodiments, each jet includes a tube (not shown) connecting the venturi jets to pipes 182 to also introduce carbon dioxide to the liquid and cause micro bubbles to be dispersed into the liquid in the channels. Further to enhancing the gas to liquid ratio, the velocity of the liquid and gas entering the main flow of the channels causes turbulence in the liquid which aids the mixing of the gas and liquid and improving the flow of the liquid along the channels.

[00134] A series of high pressure pumps 186 collect the inlet liquid for pipe 184 and venturi jets from a corresponding series of suction manifolds 188 positioned at the end of each channel, as illustrated in Figure 1 1 . Each pump 186 includes a ball valve to regulate the suction from each channel. A pump station 190 delivers the liquid to the liquid distribution manifold positioned adjacent and under the carbon dioxide manifold and connected to walls 50. Pump station 190 is also at least partially responsible for regulating the flow of carbon dioxide along pipe 178.

[00135] The liquid flow from the venturi jets is balanced by the liquid being removed from the channels through the suction line positioned at the end of each channel. This configuration improves the turbulence of the liquid and mixing capability of the carbon dioxide in the liquid. The flow dynamics of the whole system is not disturbed as the constant flow of liquid from position 31 to sump 61 is constant and is not interfered with by the recirculation of water through the venturi jets.

[00136] In some embodiments, the flow of liquid and carbon dioxide in the distribution system is monitored and/or controlled by a control system 192, which is in communication with external computers and processors through wireless station 104.

[00137] In another embodiment the fourth passage includes a pressure pipe positioned along the perimeter of first and subsequent channels that extends from upstream end 31 of passage 3 to a downstream end of the third passage which delivers the water from the harvesting sump to a series of jets and aspirators at intervals along the channels.

[00138] It will be appreciated that the illustrated system for growing algae provides an improved or alternative means for growing algae. The present invention allows for efficient growing of large quantities of algae suitable for pharmaceuticals, bio diesel and high protein animal feed stock. The present invention produces algae using a smaller carbon footprint than bio reactors and has much smaller land requirements than open ponds.

[00139] The present invention provides other advantages in growing algae over the known methods of open ponds and bio reactors, including:

Highly efficient production of algae.

Accommodates the cultivation and growth of algae of different species and divisions, and allow the use of fresh water, saline water, treated water, or a combination of the three.

Continuous production of algae within a substantially closed system.

Relatively intense use of available area.

Relatively low capital costs.

Reduced reliance upon moving mechanical agitators.

Short culturing time compared to open single race ponds

Substantially less contamination from dust and airborne debris due to the short growing cycle Low energy usage.

Substantial carbon dioxide absorption as elevated amounts of carbon dioxide are readily available to the algae culture for sequestration by photosynthesis.

Applicable to non-arable land, or to stony or sandy soils.

Allows continuous automated harvesting of algae.

[00140] Reference throughout this specification to "one embodiment", "some embodiments" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, appearances of the phrases "in one embodiment", "in some embodiments" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[00141 ] As used herein, unless otherwise specified the use of the ordinal adjectives "first", "second", "third", etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.

[00142] In the claims below and the description herein, any one of the terms comprising, comprised of or which comprises is an open term that means including at least the elements/features that follow, but not excluding others. Thus, the term comprising, when used in the claims, should not be interpreted as being limitative to the means or elements or steps listed thereafter. For example, the scope of the expression a device comprising A and B should not be limited to devices consisting only of elements A and B. Any one of the terms including or which includes or that includes as used herein is also an open term that also means including at least the elements/features that follow the term, but not excluding others. Thus, including is synonymous with and means comprising.

[00143] It should be appreciated that in the above description of exemplary embodiments of the disclosure, various features of the disclosure are sometimes grouped together in a single embodiment, Fig., or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claims require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this disclosure.

[00144] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the disclosure, and form different embodiments, as would be understood by those skilled in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[00145] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the disclosure may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

[00146] Similarly, it is to be noticed that the term coupled, when used in the claims, should not be interpreted as being limited to direct connections only. The terms "coupled" and "connected," along with their derivatives, may be used. It should be understood that these terms are not intended as synonyms for each other. Thus, the scope of the expression a device A coupled to a device B should not be limited to devices or systems wherein an output of device A is directly connected to an input of device B. It means that there exists a path between an output of A and an input of B which may be a path including other devices or means. "Coupled" may mean that two or more elements are either in direct physical, electrical or optical contact, or that two or more elements are not in direct contact with each other but yet still co-operate or interact with each other.

[00147] Thus, while there has been described what are believed to be the preferred embodiments of the disclosure, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the disclosure, and it is intended to claim all such changes and modifications as fall within the scope of the disclosure. For example, any formulas given above are merely representative of procedures that may be used. Functionality may be added or deleted from the block diagrams and operations may be interchanged among functional blocks. Steps may be added or deleted to methods described within the scope of the present disclosure.