Plant filtration and growing system

Abstract

The invention relates to a system for filtering and growing plants (1), the system being partially submerged in an aquatic zone and comprising: a growth bioreactor (10) comprising an inlet (E), at least one outlet (S), and a tank (100) for holding the plants which is arranged between the inlet (E) and the outlet (S); at least one first filter pump (11) that comprises at least one first filter (110) is positioned at the inlet of the bioreactor (10) and is intended to supply the bioreactor (10) with water, and at least one second pump (12) that comprises at least one second filter (120) is positioned at the outlet (S) of the bioreactor (10) and is intended to discharge the wastewater from the bioreactor (10). The system is characterised in that the first filter (110) and the second filter (120) each comprise a monofilament membrane, the second filter (120) having a lower porosity than the porosity of the first filter (110).

Description

Description Title of the invention: Plant filtration and cultivation system Technical field

[0001] The invention relates to the technical field of filtration and cultivation systems. State of the art

[0002] Currently, the hydrosphere is polluted by agricultural fertilizers (nitrate and phosphate) and by CO2, which causes the oceans to become acidic and suffocates the most sensitive fauna. Indeed, seas, rivers, and oceans are the largest storage sites for CO2 emitted by fossil fuels.

[0003] Thus, microalgae cultivation plays an essential role in many areas, such as food, energy, health, and the environment. However, it presents major challenges, including the energy and water consumption of different cultivation systems, which hinders the development of their market.

[0004] The invention is therefore placed in this context and seeks to resolve all of the aforementioned drawbacks. Thus, the invention seeks to propose a system for filtering and growing plants that can guarantee precise and efficient filtration of the growing water for said plants. Presentation of the invention.

[0005] The invention relates to a plant filtration and cultivation system adapted to be partially submerged in an aquatic zone comprising: a plant cultivation bioreactor comprising an inlet, a tank and at least one outlet, said tank being arranged between the inlet and the outlet and intended to contain the plants, said bioreactor being configured so that water from the aquatic zone can pass through it from the inlet towards the outlet; at least one first filter pump comprising at least one first filter, said first pump being positioned at the inlet of the bioreactor and intended to supply said bioreactor with water from the aquatic zone and at least one second pump comprising at least one second filter, said second pump being positioned at the outlet of the bioreactor and intended to evacuate the wastewater from the bioreactor.The system is remarkable in that the first filter and the second filter each comprise a single-filament membrane, the second filter having a porosity lower than the porosity of the first filter.

[0006] The system can be partially submerged, so that water from the aquatic area can pass through it.

[0007] The bioreactor can be a membrane bioreactor.

[0008] The first filter of the first pump may include a nitrocellulose membrane or, but not limited to, a tangential filter, for example an Automatic “HYDROMATIC®” membrane marketed by the company AZ-industrie. The first pump can be adapted to inject water from the aquatic zone into the bioreactor. The first pump can limit the clogging of the first inlet filter.

[0009] The second filter of the second pump may comprise a monofilament filter. The second monofilament filter may limit clogging. The entire second filter may have identical porosity over the entire surface of said filter. The porosity of the second filter may have a lower porosity than the first filter, to prevent microalgae from exiting through the bioreactor outlet.

[0010] In one embodiment, the second filter comprises a tangential filtration system. Using a tangential filtration system can allow the liquid to be evacuated and all particles whose size is smaller than the porosity of said filter to be retained. This filtration system can reduce the problems of clogging of said filter, particularly compared to other more conventional filtration systems of the frontal filtration type.

[0011] The tank may have a circular cross-section. In another embodiment, the tank may have an elliptical or parallelepipedal cross-section. The tank may comprise polyethylene. In one embodiment, the tank may, for example, have dimensions of 10 meters in diameter and 1.5 meters in depth. The geometry of the tank may allow the growth of heterotrophic organisms, i.e., organisms that feed on organic substances. The geometry of the tank may allow the growth of phototrophic organisms, i.e., organisms that feed on light.

[0012] The filter pump can filter water from the hydrosphere, for example seas, oceans, lakes and rivers.

[0013] The first filter can be used to remove pathogens and natural predators of microalgae. The first filter can be monofilament.

[0014] Plants can be microalgae. Microalgae can recycle agricultural fertilizers circulating in water. In particular, microalgae can recycle nitrate and phosphates. Microalgae can use the CO2 naturally present in water to grow.

[0015] The system can operate in a closed circuit.

[0016] This device can remove impurities in seawater, freshwater and brackish water such as sediment and zooplankton, to create an optimal cultivation environment for microalgae.

[0017] The dimensions of the system can be adapted according to the environment in which the system is installed. Thus, a system installed in a river may have smaller dimensions than a system installed in a lake, which in turn may have smaller dimensions than a system installed in the sea. The larger the device, the more it may be possible to reduce the production costs, thanks in particular to economies of scale and very low variable costs.

[0018] Advantageously, the first filter has a porosity of between 0.1 pm and 1000 pm.

[0019] The porosity of the first filter may be between 0.1 pm and 1000 pm, in particular between 5 pm and 25 pm, in particular it may be 20 pm.

[0020] Advantageously, the second filter has a porosity of between 1 pm and 1500 pm.

[0021] The porosity of the second filter can be between 1 and 1500 pm, in particular between 5 pm and 15 pm, in particular it can be 10 pm.

[0022] The second filter may have a porosity less than the diameter of the microalgae.

[0023] Advantageously, the second filter is treated with an anti-clogging substance.

[0024] The anti-clogging substance can prevent the filters from clogging. The anti-clogging substance can be adapted to release copper oxide-based biocides capable of slowing the proliferation of biofilms. Clogging can be due in particular to the presence in the hydrosphere of microorganisms producing viscous exopolysaccharides which can produce biofilms that clog said filter. Thus, the use of an anti-clogging substance can limit the proliferation of biofilm and therefore can limit the clogging of said filter. Therefore, limiting clogging can facilitate and / or increase the flow rate of water passing through the second pump equipped with the second filter. It may therefore be possible, thanks to this system, to use only water from the hydrosphere.

[0025] Advantageously, the tank includes a sensor adapted to determine a level of nitrate contained in the water of said tank.

[0026] Advantageously, the tank includes a sensor adapted to determine a level of CO2 contained in the water of said tank.

[0027] Advantageously, the tank comprises a control unit adapted to cooperate with the nitrate sensor and the CO2 sensor and to control the first filter pump so that when one of the sensors detects a level of nitrate and / or CO2 below a threshold value, it activates the first pump.

[0028] When the nitrate sensor and / or the CO2 sensor detect a nitrate and / or CO2 concentration in the tank above a threshold value, the control unit can be adapted to control the first filter pump so that the incoming water flow is limited.

[0029] Conversely, when the nitrate sensor and / or the CO2 sensor detect a nitrate and / or CO2 concentration in the tank below a threshold value, the control unit can be adapted to control the first filter pump so that the incoming water flow rate is increased.

[0030] The pH of the water in the tank may be alkaline. CO2 consumption can cause the pH in the tank to increase. Activating the first pump and the second pump by the control unit can allow the water in the tank to be renewed and can therefore regulate the pH.

[0031] Therefore, the regulation of the water inlet and outlet in the bioreactor tank can be carried out automatically. This automated regulation can reduce energy consumption to a strict minimum.

[0032] The carbon to nitrogen ratio is an element that can be decisive for the cultivation of microalgae, it is this which can guide the growth of the strains or on the contrary the accumulation of reserve or resistance molecules. A high ratio, for example a ratio greater than or equal to 50:1, can limit the growth of the cells and increase the quantity of reserve or resistance molecules, a ratio that can be found in the depths of marine environments due to the increase in CO2 in deep waters. A low ratio, for example a ratio less than or equal to 6:1, can allow for a high growth rate and reduce the quantity of reserve or resistance molecules, a ratio that can be found in the surface waters of marine environments, due to the decrease in CO2 and the high presence of nitrogen. The sensors as well as the control unit can regulate this ratio by controlling the first pump and the second pump.

[0033] Advantageously, each of the first and second pumps comprises a pre-filtration device.

[0034] The pre-filtration device may include a strainer. The strainer may include a perforated sheet metal used to stop foreign matter at the opening of a pipe. The strainer may help limit the clogging of the filter in front of which it is installed. Each of the filters in the system may include a strainer.

[0035] Advantageously, the pre-filtration device has a porosity greater than the first and second filters.

[0036] The strainer may have a higher porosity than the filter in front of which it is installed.

[0037] Advantageously, the tank comprises a water level detection device and a draining device adapted to cooperate with the control unit so that when the water level is below or above a threshold value, the control unit activates the first pump or the second pump.

[0038] The drain device may include an overflow from the tank.

[0039] When the detection device detects a water level in the tank below a threshold value, the control unit can be adapted to control the first filter pump so that water enters the tank.

[0040] Conversely, when the detection device detects a water level in the tank above a threshold value, the control unit can be adapted to control the first filter pump so that the entry of water into the tank is stopped and / or to control the water level detection device so that water exits the tank.

[0041] Advantageously, the plants contained in the tank include microalgae.

[0042] Microalgae cultivation can reduce atmospheric CO2 levels by absorbing CO2 from the microalgae. Microalgae may include a specific strain of Haematococcus Pluvalis with a high astaxanthin yield. Brief description of the figures.

[0043] Other advantages and characteristics of the present invention are now described with the aid of examples which are purely illustrative and in no way limitative of the scope of the invention, and from the appended drawings, drawings in which the various figures represent:

[0044] [Fig. 1] schematically represents a system for filtering and growing plants according to one embodiment.

[0045] In the following description, elements which are identical, by structure or by function, appearing in different figures retain, unless otherwise specified, the same references. Description of an embodiment.

[0046] [Fig. 1] shows a diagram of the plant filtration and cultivation system 1 according to one embodiment.

[0047] [Fig. 1] depicts a plant filtration and cultivation system 1. System 1 is installed in an aquatic area, so that water from the aquatic area can flow through it.

[0048] The system 1 comprises a plant culture bioreactor 10 comprising an inlet E, a tank 100 and at least one outlet S. The tank 100 is arranged between the inlet E and the outlet S and is intended to contain the plants. The bioreactor 10 is configured so that water from the aquatic zone passes through it from the inlet E towards the outlet S. The bioreactor 10 is a membrane bioreactor.

[0049] The plants contained in the tank include microalgae.

[0050] The system 1 comprises a first filter pump 11 comprising at least one first filter 110. The first pump 11 is positioned at the inlet E of the bioreactor 10 and intended to supply said bioreactor 10 with water from the aquatic zone.

[0051] The first filter 110 of the first pump 11 comprises a nitrocellulose membrane. The first pump 11 is adapted to inject water from the aquatic zone into the bioreactor 10. The first pump 11 makes it possible to limit the fouling of the first filter 110 at the inlet E. The filter pump 11 makes it possible to filter the water coming from the hydrosphere in which the system 1 is installed. The first filter 110 makes it possible to eliminate pathogens and natural predators from the microalgae. The first filter 110 is monofilament. The first filter 110 has a porosity of 20 pm.

[0052] The system 1 comprises a second pump 12 comprising at least one second filter 120, said second pump 12 being positioned at the outlet S of the bioreactor 10 and intended to evacuate the waste water from said bioreactor 10.

[0053] The second filter 120 of the second pump 12 comprises a monofilament filter. The second filter 120 of the second pump comprises a tangential filtration system. The second filter 120 makes it possible to limit clogging. The entire second filter 120 has an identical porosity over the entire surface of said filter 120. The porosity of the second filter 120 has a lower porosity than the first filter 110, to prevent the microalgae from exiting through the outlet S of the bioreactor 10. The second filter 120 has a porosity of 10 μm. The second filter 120 has a porosity smaller than the diameter of the microalgae. The second filter 120 is treated with an anti-clogging substance to prevent the filters from clogging.

[0054] The first filter 110 and the second filter 120 each comprise a single-filament membrane. The second filter 120 has a porosity lower than the porosity of the first filter 110.

[0055] Each of the first and second pumps comprises a pre-filtration device (not shown). The pre-filtration device comprises a strainer. The strainer comprises a perforated sheet metal used to stop foreign bodies at the opening of a pipe. The strainer makes it possible to limit the fouling of the filter 110, 120 in front of which it is installed. Each of the filters 110, 120 of the system comprises a strainer. The pre-filtration device has a porosity greater than the first 110 and second 120 filters.

[0056] The tank 100 has a circular cross-section. The tank 100 comprises polyethylene. The tank has dimensions of 10 meters in diameter and 1.5 meters in depth. The tank 100 comprises a sensor 100.1a adapted to determine a level of nitrate contained in the water of said tank 100. The tank 100 comprises a sensor 100.1b adapted to determine a level of CO2 contained in the water of said tank 100.

[0057] The tank 100 comprises a control unit adapted to cooperate with the nitrate sensor 100.1a and the CO2 sensor 100.1b and to control the first filter pump 11 so that when one of the sensors 100.1a, 100.1b detects a level of nitrate and / or CO2 below a threshold value, it activates the first pump 11.

[0058] When the nitrate sensor 100.1a and / or the CO2 sensor 100.1b detect in the tank 100 a concentration of nitrate and / or CO2 greater than a threshold value, the control unit is adapted to control the first filter pump 11 so that the incoming water flow rate is limited.

[0059] Conversely, when the nitrate sensor 100.1a and / or the CO2 sensor 100.1b detect in the tank 100 a concentration of nitrate and / or CO2 lower than a threshold value, the control unit is adapted to control the first filter pump 11 so that the incoming water flow rate is increased.

[0060] The pH of the water in the tank is alkaline. The consumption of CO2 causes the pH in the tank 100 to increase. The activation of the first pump 11 and the second pump 12 by the control unit allows the water in the tank 100 to be renewed and therefore allows the pH to be regulated.

[0061] The regulation of the inlet and outlet of water in the tank 100 of the bioreactor 10 is carried out in an automated manner.

[0062] The tank 100 comprises a water level detection device 100.2 and a draining device 100.3 adapted to cooperate with the control unit so that when the water level is lower or higher than a threshold value, the control unit activates the first pump 11 or the second pump 12. The draining device 100.3 comprises an overflow of the tank 100.

[0063] When the detection device 100.2 detects a water level in the tank 100 below a threshold value, the control unit is adapted to control the first filter pump 11 so that water enters the tank 100. Conversely, when the detection device 100.2 detects a water level in the tank 100 above a threshold value, the control unit is adapted to control the first filter pump 11 so that the entry of water into the tank 100 is stopped and / or to control the water level detection device 100.2 so that water leaves the tank 100.

[0064] The foregoing description clearly explains how the invention achieves the objectives it sets for itself, namely to propose a system for filtering and cultivating plants making it possible to guarantee precise and efficient filtration of the water used to cultivate said plants, by proposing a system for filtering and cultivating plants adapted to be partially submerged in an aquatic zone comprising: a plant cultivation bioreactor comprising an inlet, a tank and at least one outlet, said tank being arranged between the inlet and the outlet and intended to contain the plants, said bioreactor being configured so that water from the aquatic zone can pass through it from the inlet towards the outlet;at least one first filter pump comprising at least one first filter, said first pump being positioned at the inlet of the bioreactor and intended to supply said bioreactor with water from the aquatic zone and at least one second pump comprising at least one second filter, said second pump being positioned at the outlet of the bioreactor and intended to evacuate the waste water from the bioreactor; the first filter and the second filter each comprise a monofilament membrane, the second filter having a porosity lower than the porosity of the first filter.;

[0065] In any event, the invention cannot be limited to the embodiments specifically described in this document, and extends in particular to all equivalent means and to any technically effective combination of these means.

Claims

Claims

1. Plant filtration and cultivation system (1) adapted to be partially submerged in an aquatic zone comprising: • A bioreactor (10) for growing plants comprising an inlet (E), a tank (100) and at least one outlet (S), said tank (100) being arranged between the inlet (E) and the outlet (S) and intended to contain the plants, said bioreactor (10) being configured so that water from the aquatic zone can pass through it from the inlet (E) towards the outlet (S); • At least one first filter pump (11) comprising at least one first filter (110), said first pump (11) being positioned at the inlet of the bioreactor (10) and intended to supply said bioreactor (10) with water from the aquatic zone and at least one second pump (12) comprising at least one second filter (120), said second pump (12) being positioned at the outlet (S) of the bioreactor (10) and intended to evacuate the waste water from the bioreactor (10); Characterized in that the first filter (110) and the second filter (120) each comprise a single-filament membrane, the second filter (120) having a porosity lower than the porosity of the first filter (110).

2. Filtration system (1) according to the preceding claim, characterized in that the first filter (110) has a porosity of between 0.1 pm and 1000 pm.

3. Filtration system (1) according to one of the preceding claims, characterized in that the second filter (120) has a porosity of between 1 pm and 1500 pm.

4. Filtration system (1) according to one of the preceding claims, characterized in that the second filter (120) is treated with an anti-clogging substance.

5. Filtration system (1) according to one of claims 1 to 4 characterized in that the tank (100) comprises a sensor (100.1a) adapted to determine a level of nitrate contained in the water of said tank (100).

6. Filtration system (1) according to one of claims 1 to 4 characterized in that the tank (100) comprises a sensor (100.1b) adapted to determine a level of CO? contained in the water of said tank (100).

7. Filtration system (1) according to one of claims 5 or 6 characterized in that the tank (100) comprises a control unit adapted to cooperate with the nitrate sensor (100.1a) and the CO2 sensor (100.1b) and to control the first filter pump (11) so that when one of the sensors (100.1a; 100.1b) detects a level of nitrate and / or CO2 lower than a threshold value, it activates the first pump (11). [Claim s] Filtration system (1) according to one of the preceding claims, characterized in that each of the first (11) and second (12) pumps comprises a pre-filtration device.

9. Filtration system (1) according to the preceding claim, characterized in that the pre-filtration device has a porosity greater than the first (110) and second filters (120).

10. Filtration system (1) according to one of claims 7 to 9 characterized in that the tank (100) comprises a water level detection device (100.2) and a draining device (100.3) adapted to cooperate with the control unit so that when the water level is lower or higher than a threshold value, the control unit activates the first pump (11) or the detection device (100.2). [Claim ll]Filtration system (1) according to one of the preceding claims, characterized in that the plants contained in the tank (100) comprise microalgae.

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