Apparatus and Method for Removing Hydrocarbons from a Body of Water

Abstract

The present invention relates to a device and an apparatus and relative method for removing hydrocarbons from a water body, in particular for the remediation of hydrophobic contaminated hydrocarbons present as a demixed phase. The device of the invention is equipped with at least one sensor which determines its position with respect to the demixed phase in the body of water, allowing automated modification of the position of the device with respect to the demixed phase in optimising its separation and recovery.

Claims

1. Apparatus (10) for the removal of a demixed organic phase (40), which extends from a lower interface surface (WO) with a heavier phase to an upper interface surface (GO), with a lighter phase in a contaminated body of water, comprising a mobile device (20) immersible in the contaminated body of water, comprising a selectively petmeable filter element (130) constituting a separation cavity (100), a collection tank (210) constituting a collecting cavity (200) suitable for containing hydrocarbons filtered by the filter element (130), the said separation cavity (100) and collecting cavity (200) being fluidically connected to each other, suspension and handling means (140) of the mobile device (20) for the automatic control of its positioning with respect to the demixed organic phase (40) to be removed, the apparatus (10) being characterised in that it comprises at least one means of determination of the relative position of the mobile device (20) with respect to the upper interphase surface (GO) of the demixed organic phase (40) to be removed, a surface device (30) comprising a remote control and handling unit (700) of the mobile device (20), a motor (600) controlled by the unit (700) and connected to the means of suspension and handling (140), the means of determination of the relative position being connected to the unit (700) and exchanging the detected information with it.

2. Apparatus (10) according to claim 1, wherein the means of determination of the mobile device (20) of the relative position with respect to the upper interface surface (GO) of the demixed organic phase (40) is a level sensor (400), installed in a predetermined position relative to the mobile device (20), configured to measure its distance from the upper interface surface (GO) of at least one demixed organic phase (40) to be removed.

3. Apparatus (10) according to claim 1, wherein the means of determination of the relative position of the mobile device (20) with respect to the upper interface surface (GO) of the demixed organic phase (40) is a phase sensor (500), installed in a predetermined position relative to the mobile device (20), configured to detect the phase of the fluid in which it is immersed.

4. Apparatus (10) according to claim 1, comprising as a means of determination of the relative position of the mobile device (20) with respect to the demixed organic phase (40) to be removed a level sensor (400), installed in a predetermined position of the mobile device (20), configured to measure its distance from the upper interface surface (GO) of at least one demixed organic phase (40) to be removed and one phase sensor (500), installed in a predetermined position with respect to the mobile device (20), configured to detect the phase of the fluid in which it is immersed and to determine the thickness of the residual demixed organic phase (40).

5. Apparatus (10) according to claim 1 comprising at least one first phase sensor (500) and one second phase sensor (501) as means of determining the position of a mobile device (20) with respect to the upper interface surface (GO), the first phase sensor (500) being installed in a predetermined position relative to the mobile device (20) and configured to obtain its distance from the upper interface surface (GO) of at least one demixed organic phase (40) to be removed, and the second phase sensor (501) being installed in a lower position on the first phase sensor (500) in a predetermined position relative to the mobile device (20) and configured to identify the presence of the demixed organic phase (40).

6. Apparatus (10) according to claim 1 comprising at least one level sensor (400), installed in a predetermined position from the mobile device (20), configured to measure its distance from the upper interface surface (GO) of at least one demixed organic phase (40) to be removed, at least one first phase sensor (500) and at least one second phase sensor (501), the first phase sensor (500) being installed in a predetermined position relative to the mobile device (20) and configured to detect the presence of at least one demixed organic phase (40) to be removed, and the second phase sensor (501) being installed in a lower position on the first phase sensor (500) in a predetermined position relative to the mobile device (20) and configured to detect the presence of the demixed organic phase (40).

7. Apparatus (10) according to claim 1 in which the selectively permeable filter element (130) is a hydrophobic filter.

8. Apparatus (10) according to claim 1 characterised in that it comprises a pump (300), fluidically connected to the collecting cavity (200), configured for emptying the collection tank (210) by means of an evacuation duct (320) upon command of a level sensor (310) installed inside the collection tank (210).

9. Apparatus (10) according to claim 1, wherein the remote control and handling unit (700) comprises at least one rechargeable battery (800), installed on the surface device (30), for the feeding of apparatus (10) without the use of additional external power supply sources.

10. (canceled)

11. Apparatus (10) according to claim 1 wherein at least one of the sensors (400, 500, 501, 310) is connected to the control and handling unit (700) by means of wireless technology.

12. (canceled)

13. Apparatus (10) according to claim 1, wherein the mobile device (20) has maximum size of transverse dimensions, measured orthogonally to a longitudinal axis (A), less than 100 mm.

14. An automatic process for the removal of a demixed organic phase (40) which extends from a lower interface surface (WO) with a heavier phase at a higher interface surface (GO), with a lighter phase in the contaminated body of water comprising the phases of: a) providing an apparatus according to claim 1; d) lowering the mobile device (20) into the contaminated body of water; e) determining the position of the mobile device (20) with respect to the upper interface surface (GO) of the demixed organic phase (40) on the basis of the information from one or more sensors (400,500,501) of the mobile device (20); f) selectively filtering the demixed organic phase (40); g) automatically changing the position of the mobile device (20) on the basis of the information from one or more sensors (400,500,501) of the mobile device (20), by acting on the motor (600) controlled by the remote control and handling unit (700); h) removing the mobile device (20) from the contaminated body of water.

15. Process as claimed in claim 14 comprising the phases of: b) defining a threshold value (LS), a lower value (L2), an upper reference value (L1) and a normal operating value (Lopt), comprised within the lower value (L2) and the upper value (L1), of the distance of the level sensor (400) from the upper interface surface (GO) of the demixed organic phase (40) to be removed; c) programming the control and handling unit (700) by inserting the predefined threshold values (LS), upper (L2), lower (L1) and of normal operation (Lopt) of the distance of the level sensor (400) from the higher interface surface (GO) of the demixed organic phase (40) to be removed; wherein phase g) is carried out when the distance of the level sensor (400) from the upper interface surface (GO) of the demixed organic phase (40) to be removed is less than the higher value (L1) or is greater than the lower value (L2) predefined, maintaining the position of the mobile device (20) at the normal operating value (Lopt).

16. Process as claimed in claim 15 wherein phase d) is performed with a vertical rapid handling speed (Vr) of the mobile device (20), ranging from 50 mm/s to 300 mm/s, until the sensor level (400) does not measure a distance from the upper interface surface (GO) of the demixed organic phase (40) equal to or higher of the threshold value (LS);

17. Process as claimed in claim 15 wherein phase h) is carried out with a vertical rapid handling speed (Vr) of the mobile device (20), comprising between 50 mm/s and 300 mm/s, from when the level sensor (400) measures a distance from the upper interface surface (GO) of the demixed organic phase (40) equal to or less than the threshold value (LS);

18. The process as claimed in claim 15 wherein phase g) is carried out with a vertical slow moving speed (Vl) of the mobile device (20) ranging from 5 mm/s to 15 mm/s;

19. Process as claimed in claim 14 comprising the steps of: i) defining a time interval of standing (T1) of the mobile device (20) and programming the timer accordingly (710); j) lowering the mobile device (20) with a fast vertical handling speed Vr of handling until detecting the demixed organic phase (40) by the phase sensor (500); k) lifting the mobile device (20) with a slow vertical handling speed (Vl) until its complete disengagement from the liquid phase on the basis of the information from the phase sensor (500); l) lowering the mobile device (20) with a slow vertical handling speed of (Vl) until detection of the demixed organic phase (40) by the phase sensor (500); m) starting the programmable timer (710) and counting the mobile (20) standing time interval (T1) in the demixed organic phase (40); n) repeating for a predetermined number of times phases k) to m) previously described at the expiry time of the temporary standing interval (T1).

20. Process as claimed in claim 19 comprising the phases of: o) lifting the mobile device (20) with a vertical slow handling speed (Vl) until its complete disengagement from the liquid phase on the basis of the phase sensor information (500), when the phase sensor (500) does not detect the demixed organic phase (40); p) keeping the mobile device (20) stationary in the position of complete disengagement from the liquid phase for a predetermined pause time (Tp); q) repeating for a predetermined number of times phases j) to p) described above.

21. Process as claimed in claim 19 comprising the phases of: p) lifting the mobile device (20) with a vertical slow handling speed (Vi) until its complete disengagement from the liquid phase, when the phase sensor (500) does not detect the demixed organic phase (40); pp) keeping the mobile device (20) stationary in a fully disengaged position from the liquid phase when the second phase sensor 501 does not detect the presence of the demixed organic phase (40); q) repeating for a predetermined number of times phases j) to p) described above.

22. The process as claimed in claim 15 comprising the phases of: p) lifting the mobile device (20) with a slow vertical handling speed Vi until its complete disengagement from the liquid phase on the basis of the information from the phase sensor 500, when the phase sensor 500 does not detect the demixed organic phase (40); pp) keeping the mobile device (20) stationary in a fully disengaged position from the liquid phase when the second phase sensor 501 does not detect the presence of the demixed organic phase (40); r) repeating for a predetermined number of times the phases from d) to g).

Description

[0028] The characteristics and advantages of the present invention will become apparent from the following description of a non-limiting example of it with reference to the figures in the accompanying drawings, in which:

[0029] FIG. 1 is a simplified diagrammatic view of apparatus 10 comprising the mobile device 20 and the surface apparatus 30 with at least one level sensor 400 and the principal elements required for operation and with parts omitted for clarity;

[0030] FIG. 2 is a simplified diagrammatic view of the apparatus 10 comprising the mobile device 20 and the surface apparatus 30 with at least one phase sensor 500 and the principal elements required for operation and with parts omitted for clarity;

[0031] FIG. 2A is a simplified diagrammatic view of the apparatus 10 comprising the mobile device 20 and the surface apparatus 30 with at least one level sensor 400, at least one phase sensor 500 and the principal elements required for operation and with parts omitted for clarity;

[0032] FIG. 2B is a simplified diagrammatic view of apparatus 10 comprising the mobile device 20 and the surface apparatus 30 with at least two phase sensors 500, 501 and the principal elements required for operation and with parts omitted for clarity;

[0033] FIG. 2C is a simplified diagrammatic view of the apparatus 10 comprising the mobile device 20 and the surface apparatus 30 with at least two phase sensors 500, 501, at least one level sensor 400 and the principal elements required for operation and with parts omitted for clarity;

[0034] FIG. 3 is a simplified diagrammatic view of the mobile device 20 with reference to its optimal positioning with respect to the demixed GO gas/phase interface;

[0035] FIGS. 4 and 5 illustrate diagrammatically the mobile device 20 in two different operating conditions, indicating how the automatic positioning unit acts to optimise the recovery performance of the demixed phase 40;

[0036] FIG. 6 shows diagrammatically the LS, L1, Lopt and L2 predetermined level values with parts omitted for clarity;

[0037] In the scope of the present invention, a phase separated by other phases (for example from the aqueous or possibly from a gaseous phase) is defined as a demixed phase, present in a body of water.

[0038] In the scope of the present invention, the term upper is meant as an indication of a position within the body of water closest to the atmosphere, while the term lower is intended as an indication of a position within of the body of water closest to the bottom B. The present invention applies in a context in which a contaminated body of water contains at least one demixed organic phase 40, delimited by a lower phase interface WO with a heavier liquid 50 (e.g., water) and a upper phase interface GO with a lighter liquid or a gas 60. The bottom B delimits in a lower way the development of the body of water.

[0039] With reference to FIG. 1, the subject of the present invention is an apparatus 10 for removing a demixed organic phase 40 comprising a mobile device 20, which is immersed in the contaminated body of water and a surface apparatus 30 which controls and handles the mobile device 20. The mobile device 20 comprises a selectively permeable filtering element 130 configuring a separation cavity 100. When the apparatus is immersed in the body of water, the selectively permeable filter element 130 separates the demixed organic phase 40 into the separation cavity 100. The mobile device 20 further also comprises a collecting cavity 200 in fluid communication with the separation chamber 100 which stores the previously separated demixed organic phase 40 in the separation chamber 100. The connection between the separation chamber 100 and the collection chamber 200 is made in such a way as to allow the emptying of the separation chamber 100 and respective filling of the collection chamber 200, preferably by gravity.

[0040] The mobile device 20 has no means of floating which allows it to retain its position once immersed in the contaminated body of water.

[0041] The mobile device 20 comprises at least one means for determining the relative position of the apparatus 20 with respect to the demixed gas/phase interface GO. The apparatus 20 is provided with suspending and handling means 140 for automatic control of its positioning with respect to the demixed gas/phase interface GO.

[0042] The surface apparatus 30 comprises a remote control and handling unit 700 of the mobile device 20 and a motor 600 which, by means of the suspension and handling means 140, modifies the position of the mobile device 20 based on the commands received from the control 700. The suspension and handling means 140 can be selected from ropes, cables, belts, strands, chains whose materials may be selected from metals or their alloys, plastics, organic fibres or inorganic fibres. At least one means of determining the relative position of the apparatus 20 with respect to the demixed gas/phase interface GO is connected to the control and handling unit 700 and exchanges the detected information with this. The control 700, based on the received data and predefined reference values, implements independently the logics needed to automatically change the position of the mobile device 20 by selectively assigning the commands to the 600 motor.

[0043] In a preferred configuration of the invention, the means for determining the relative position of the mobile device 20 with respect to the demixed gas/phase interface GO is a level sensor 400 installed in a predetermined position with respect to the mobile device 20 and configured to measure its distance from the surface of the upper GO interface of at least one demixed organic phase 40 to be removed. Since the position of the level sensor 400 is known with respect to the mobile device 20, based on the detection of the distance of the level sensor 400 from the upper interface surface GO, it is possible to determine the position of the selectively permeable filter element 130 with respect to the demixed organic phase 40 to be removed.

[0044] With reference to FIG. 2, in a further preferred configuration of the invention, the means for determining the relative position of the mobile device 20 with respect to the upper demixed gas/phase interface GO is a phase sensor 500, installed in a predetermined position relative to the mobile device 20, configured to detect the presence of demixed organic phase 40 in the fluid in which it is immersed. The signal of detection by the phase sensor 500 of demixed organic phase 40 is sent to the control and handling unit 700. In case of detection by the 500 sensor phase of the water phase, the remote control and handling unit 700 commands the motor 600 independently to modify the positioning of the mobile apparatus 20 by lifting it out of the liquid phase.

[0045] It will be apparent from the description that the combination of information from the level sensor 400 and the phase sensor 500 is particularly advantageous to make the independent handling behaviour of the mobile device 20 more precise and effective. In a preferred configuration of the invention as in FIG. 2A, therefore, apparatus 10 comprises, as a means for determining the relative position of the mobile apparatus 20 with respect to the demixed gas/phase interface GO, at least one level sensor 400, installed in a predetermined position of the mobile device 20, configured to measure its distance from the upper surface interface GO of at least one demixed organic phase 40 to be removed and at least one phase sensor 500 installed in a predetermined position with respect to the mobile device 20, configured to detect the phase of the fluid in which it is immersed and to determine the thickness of the demixed organic phase 40.

[0046] In a preferred configuration of the invention as in FIG. 2B, apparatus 10 comprises at least a first phase sensor 500 and a second phase sensor 501 as means for determining the relative position of the mobile device 20 with respect to the surface of the upper interface GO; the first phase 500 sensor is installed in a predetermined position with respect to the mobile device 20 and configured to obtain its distance from the upper interface surface GO of at least one demixed organic phase 40 to be removed and the second phase sensor 501 is installed below the first phase sensor 500 in a predetermined position with respect to the mobile device 20 and configured to detect the presence of demixed organic phase 40.

[0047] In a further preferred configuration of the invention as in FIG. 2C, the apparatus 10 comprises, as a means for determining the relative position of the mobile device 20 with respect to the demixed gas/phase interface GO, at least one level sensor 400, installed in a predetermined position of the mobile device 20, configured to measure its distance from the surface of the upper interface GO of at least one demixed organic phase 40 to be removed, at least one first phase sensor 500 and at least one second phase sensor 501; the first phase sensor 500 is installed in a predetermined position with respect to the mobile device 20 and configured to detect the presence of a minimum demixed organic phase 40 to be removed and the second phase sensor 501 is installed below the first phase sensor 500 in a predetermined position with respect to the mobile device 20 and configured to detect the presence of demixed organic phase 40.

[0048] The selectively permeable hydrophobic filter elements are known per se; they are also known selectively permeable oleophilic filtering elements.

[0049] In a preferred configuration of the invention, the selectively permeable filter element 130 of the apparatus 10 is a hydrophobic filter. In this configuration, the capacity for removal of the demixed organic phase 40 is greatly improved by reducing the water trapped downstream of the separation. The hydrophobic filter is susceptible to prolonged contact with an aqueous phase which results in its premature deterioration and drop in selective filtration capacity; it is therefore important that the mobile device 20 in which the hydrophobic filter is installed is always positioned optimally with respect to the demixed organic phase 40 and in respect to the lower phase interface WO.

[0050] The invention described above allows for a proper control of the positioning of the mobile device 20 automatically and continuously without the intervention of the operator based on the information detected by the sensors installed on the mobile device 20.

[0051] The demixed organic phase 40, once captured in the separation cavity 100 by means of the selectively permeable filter element 130, is conveyed into the collecting cavity 200 where it accumulates. In order to avoid the blockage of the mobile device 20 when the collection cavity 200 is full, the collecting tank 210 must be emptied periodically; with a view to the object of the invention having an apparatus 10 in automatic operation, the emptying of the collection tank 210 is effected by means of a pump 300 controlled by a level sensor 310 installed inside the collection tank 210.

[0052] In a preferred configuration of the invention, the apparatus 10 comprises a pump 300, fluidly connected to the collecting cavity 200, configured to empty the collecting tank 210 by means of an evacuation duct 320 on the command of a level sensor 310 installed inside the collection tank 210.

[0053] The apparatus 10, for its proper operation, needs to be electrically powered for the functions of the control and handling unit 700, for the actuation of the motor 600, for the functions of the sensors 310, 400, 500 and for any further additional components.

[0054] The necessary power supply can be made by connecting to an electrical network or by using batteries. The solution of supply via batteries, preferably rechargeable, allows the apparatus 10 to be even more versatile and independent of the context in which it is used without the need for an external power supply.

[0055] In a preferred configuration of the invention, therefore, the surface apparatus 30 of the apparatus 10 comprises at least one rechargeable battery 800 for supplying the apparatus 10 without the use of additional external power sources.

[0056] In a further preferred configuration of the invention, in order to increase the independence of operation and improve availability, the apparatus 10 comprises at least one solar panel 900 configured to recharge at least one rechargeable 800 battery.

[0057] As previously advanced, in some operational situations related to the contaminated levels of the body of water or to the thickness of the demixed organic phase 40, it is desirable to be able to automatically lift the mobile device 20 from the body of water for a programmed time period. To this end, it is necessary to provide a programmable timer which, connected to the control and handling unit 700, cooperates in the selective timing of the mobile device 20 from the body of water.

[0058] In a preferred configuration of the invention, the remote control and handling unit 700 of the apparatus 10 comprises at least one programmable timer 710.

[0059] The adoption of a configuration of apparatus 10 comprising at least two phase sensors 500, 501 appropriately positioned as described above, allows the implementation of a control over the amount of demixed organic phase 40 present and over the method of engagement and disengagement of the mobile device 20 with respect to the body of water. In particular, the first sensor 501 detects the presence of demixed organic phase 40 in the fluid in which it is immersed by sending the signal of detection of demixed organic phase 40 to the control and handling control 700.

[0060] In case of detection by the phase sensor 500 of the water phase, the remote control and handling unit 700 independently controls the motor 600 to modify the positioning of the mobile apparatus 20 by lifting it out of the liquid phase. When the mobile device 20 is lifted out of the liquid phase to a distance preferably between 10 and 30 cm from the upper phase interface GO with respect to the lower part of the mobile device 20, the second phase sensor 501, located below the first phase 500 sensor, remains in contact with the liquid phase; the said sensor 501 sends a signal to the control and handling control unit 700 in the case of the detection of a demixed organic phase 40 so that the positioning of the mobile device 20 is automatically modified by returning the mobile device 20 to immersion in the liquid phase to continue with the filtering operations. In this way, the second phase sensor 501 acts as a control sensor which guarantees the re-immersion of the mobile device 20 in the liquid phase only when there is once again present an appropriate amount of demixed organic phase 40 to be removed.

[0061] As described above, the level sensor 400, the phase sensors 500 and 501 are connected to the control and handling unit 700 respectively by the wiring 410, 510, and 511. The information detected by the sensors 400, 500 and 501 is thereby conveyed to the control 700 for processing. The use of wireless technology for the connection of the sensors 400, 500, 501 to control panel 700 represents a preferred and advantageous implementation for apparatus 10, enabling the construction of a simplified mobile device 20 and easier handling in operation.

[0062] The bodies of water contaminated by demixed organic phases can be of various types; the use of apparatus 10 in the remediation of contaminated water is frequent. Normally aquifers are equipped with piezometric wells whose diameter ranges from 50 mm to 150 mm. The use of the apparatus 10 of the present invention in piezometric wells is particularly advantageous as it allows the remediation of polluted water by using existing infrastructures speeding up and simplifying operations.

[0063] In a preferred configuration of the invention, mobile device 20 has a maximum cross-sectional dimension, measured orthogonally to a longitudinal axis A, equal to or less than 100 mm, preferably between 45 mm and 95 mm.

[0064] Another object of the present invention is an automatic process for removing a demixed organic phase 40 from a contaminated body of water; the automatic process object of the invention utilises the apparatus 10 which may be provided with one or more sensors to determine the position of the mobile apparatus 20 with respect to the demixed gas/phase interface GO. Based on the information received from one or more sensors installed in the mobile device 20, the control and handling unit 700 determines which action is most appropriate between the partial lifting or lowering, the complete disengagement or the standing of the apparatus 20 immersed in the contaminated fluid. The apparatus may operate on the basis of the measurements of at least one level sensor 400 or at least one phase sensor 500 or at least two phase sensors 500, 501 or combining the information from at least two level sensors 400 and phase sensors 500 or combining the information from at least three level sensors 400, phase sensors 500 and 501. In preferred configurations the apparatus may be provided with additional sensors, preferably configured to determine the position of the apparatus 20 in the contaminated body of water.

[0065] It is therefore an object of the present invention to provide for an automatic process for removing a demixed organic phase 40 extending from a lower interface surface WO with a heavier phase at an upper surface GO with a lighter phase in the contaminated body of water comprising the phases of: [0066] a) providing an apparatus 10 as claimed in any of the claims 1 to 13; [0067] d) lowering the mobile device 20 into the contaminated body of water; [0068] e) determining the position of the mobile device 20 with respect to the upper interface GO of the demixed organic phase 40 on the basis of the information from one or more sensors 400, 500, 501 of the mobile device 20; [0069] f) selectively filtering the demixed organic phase 40; [0070] g) automatically modifying the position of the mobile device 20 based on the information from one or more sensors 400, 500, 501 of the mobile device 20 acting on the motor 600 controlled by the remote control and handling unit 700; [0071] h) removing the mobile device 20 from the contaminated body of water.

[0072] The above-described process allows the position of the selectively permeable filter element 130 to be automatically adjusted in such a way as to maintain it in an effective operating range. The apparatus 10 is thus completely independent and operates with a reduced need for maintenance and surveillance by the operator.

[0073] The positioning of the selectively permeable filtering element 130 can be made more effective by defining a predetermined optimum operating value Lopt and by an interval around the Lopt value determined by a lower value L2 and a upper value L1, in which Lopt is included; a threshold value LS is also defined used to optimise the positioning process of the mobile device 20 with respect to the demixed gas/phase interface GO. The LS, Lopt, L1, and L2 values are values measured from the upper interface surface GO of the demixed organic phase 40 to be removed.

[0074] Preferably the value of LS varies between 20 mm and 100 mm, the value of L1 varies between 340 mm and 440 mm and the value of L2 varies between 350 mm and 450 mm. The control and handling unit 700 is then programmed by entering the predefined values of LS, L1 and L2 and Lopt.

[0075] During the selective filtration phase of the demixed organic phase 40, when at least one level sensor 400 is present, the automatic modification of the position of the mobile device 20 is performed on the basis of reading the values measured by the level sensor 400 with respect to the surface of the upper interface GO. When the value measured by the sensor 400 is lower than the upper value L1, the mobile device 20 is lowered to the depth of the water body, while when the value measured by the sensor 400 is greater than the lower value L2, the mobile device 20 is lifted in the body of water in order to keep the mobile device 20 at normal operating value Lopt.

[0076] In a preferred configuration of the invention, the automatic process for removing a demixed organic phase 40 which extends from a lower interface surface WO with a heavier phase to an upper interface surface GO with a lighter phase in the body of contaminated water further comprises the phases of: [0077] b) defining a threshold value LS, a lower value L2, an upper reference value L1 and a normal operation value Lopt, between the lower value L2 and the upper value L1, of the distance of the level sensor 400 from the surface of the upper interface GO of the demixed organic phase 40 to be removed; [0078] c) programming the control and handling unit 700 by inserting the predefined threshold LS, lower L2, upper L1 and normal operation Lopt values of the distance of the level sensor 400 from the upper surface GO of the demixed organic phase 40 to be removed;
in which phase g) described above is carried out when the distance of the level sensor 400 from the upper interface GO of the demixed organic phase 40 to be removed is less than the upper value L1 or greater than the lower value L2, maintaining the position of the mobile device 20 at the normal operating value Lopt.

[0079] In order to make the operations of the apparatus 10 rapid and more efficient, it has been found advantageous to be able to move the mobile device 20 at a vertical velocity which may vary; in particular, a rapid vertical handling velocity Vr, whose value is between 50 mm/s and 300 mm/s, is defined and a slow vertical handling speed Vl whose value is between 5 mm/s and 15 mm/s. In a preferred configuration of the invention, it is possible to determine for which phases the mobile device 20 is moved with the velocity Vr or Vl. In a preferred configuration of the invention, phase d) of the above-described process is carried out at a rapid vertical handling velocity Vr of the mobile device 20, comprised between 50 mm/s and 300 mm/s, until the level sensor 400 measures a distance from the upper interface surface GO equal to or greater than the threshold value LS.

[0080] In a further preferred configuration of the invention, phase h) is carried out at a rapid vertical handling velocity Vr of the mobile device 20, between 50 mm/s and 300 mm/s, when the level sensor 400 measures a distance from the upper interface surface GO equal to or less than the LS threshold value.

[0081] In a further preferred configuration of the invention, phase g) is carried out with a slow vertical handling speed Vl of the mobile device 20 between 5 mm/s and 15 mm/s.

[0082] The automatic process for removing a demixed organic phase 40 may be performed by using at least one phase detector 500 to determine the position of the mobile device 20 with respect to the upper interface surface GO. In the configuration of the apparatus 10 comprising at least one phase sensor 500, readings from the sensor 500 are used to establish whether the mobile device 20 is immersed in a gaseous zone or in an ambient air, in an organic phase zone or in a predominantly aqueous zone. The mobile device 20 is then moved on the basis of the information received from the phase sensor 500, identifying the descent speed based on the position of the device 20 itself. Since the control of the position of the mobile device 20 via the sensor 500 is based solely on the detection of the phase in which the device is immersed, it is necessary to define a time period of standing of the device T1 to define the time period in which the device 20 stays immersed in the demixed organic phase 40.

[0083] In a preferred configuration of the invention, the automatic process for removing a demixed organic phase 40 extending from a lower WO interface surface with a heavier phase to an upper surface interface GO with a lighter phase in the body of contaminated water further comprises the steps of: [0084] i) defining a time interval T1 of the mobile device 20 and consequently programming the timer 710; [0085] j) lowering the mobile device 20 with a rapid vertical handling velocity Vr up to detecting the demixed organic phase 40 by means of the phase sensor 500; [0086] k) lifting the mobile device 20 with a slow vertical handling velocity Vl up to its complete disengagement from the liquid phase based on the information from the phase sensor 500; [0087] l) lowering the mobile device 20 with a slow vertical handling speed Vl up to detecting a demixed organic phase 40 by means of the phase sensor 500; [0088] m) activating the programmable timer 710 and counting the T1 timing interval of the standing of the mobile device 20 in the demixed organic phase 40; [0089] n) repeating for a number of times the phases from k) to m) previously described at the end of the T1 standing time interval.

[0090] When the equipment 10 operates by means of the phase sensor 500, at the moment when the demixed organic phase 40 is not detected, the mobile device 20 is lifted to its complete disengagement from the liquid phase and kept stationary in the air or gas phase for a pre-determined pause time Tp. At the end of the pause time Tp, the mobile device 20 is again lowered according to the modes already described.

[0091] In the preferred configuration of equipment 10 in which at least one first phase sensor 500 and a second phase sensor 501 are installed, the position control of the mobile device 20 when disengaged from the liquid phase is dependent on the signal from the second phase sensor 501, being installed below the first phase sensor 500, it remains immersed in the liquid phase even when the mobile device 20 is completely disengaged from the liquid phase. The remote control and handling control unit 700, based on the indication of demixed organic phase 40 performed by the second phase sensor 501, controls the motor 600 independently to modify the positioning of the mobile device 20 by immersing it in the liquid phase to continue the operation of the filtration and removal of the demixed organic phase 40.

[0092] In a preferred configuration of the invention, the automatic process for removing a demixed organic phase 40 extending from a lower WO interface surface with a heavier phase to an upper interface surface GO with a lighter phase in the body of contaminated water further comprises the phases of: [0093] o) lifting the mobile device 20 with a slow vertical handling velocity Vl until its complete disengagement from the liquid phase based on the information from the phase sensor 500, when the phase sensor 500 does not detect the demixed organic phase 40; [0094] p) keeping the mobile device 20 stationary in a complete disengaged position from the liquid phase for a predetermined pause time Tp; [0095] q) repeating the previously described phases j) to p) for a number of times

[0096] In a further preferred configuration of the invention, the automatic removal process of a demixed organic phase 40 extending from a lower WO interface surface with a heavier phase to an upper surface interface GO with a lighter phase in the body of contaminated water comprises, alternatively, phase p) described above, phase pp) of keeping the device 20 stationary, in a position of complete disengagement from the liquid phase, when the second phase sensor 501 detects the presence of demixed organic phase 40. At the moment when the phase sensor 501 again detects the demixed organic phase 40, the remote control and handling unit 700 is given a modification consensus indication for the position of the mobile device 20 to return it to immersion in the liquid phase.

[0097] The process described allows effective management of the selectively permeable filter element 130 by drastically reducing exposure for extended periods of time, thereby avoiding potential deterioration of its surface structure; furthermore, as previously described, the filtering element 130 is operative only when it is necessary, or when there is a demixed organic phase 40 with thicknesses greater than or equal to 1 mm.

[0098] An additional advantage of the present invention is that the mobile device 20 is not provided with continuous moving parts; this feature reduces energy consumption and enhances the operating independence of the equipment 10 when energised by rechargeable batteries.

[0099] As previously described, the combination of the measurements made by the level sensor 400 and the phase sensor 500 is particularly effective in determining the handling logic of the mobile device 20 with respect to the upper interface surface GO.

[0100] The combination of measurements made by the level sensor 400, the phase sensor 500, and the phase sensor 501 further helps to optimise the automatic positioning of the mobile device 20 with respect to the upper interface surface GO.

[0101] Using the information from sensors 400, 500, 501 individually or in combination, it is possible not only to keep the mobile device around the optimum Lopt position but also to avoid excessive exposure of the hydrophobic filter to water under certain specific conditions by disengaging it from the body of water.

[0102] In the preferred configuration of the above-described invention, in which the equipment 10 comprises at least one level sensor 400, one phase sensor 500 and one phase sensor 501, the mobile device 20 is lowered into the body of contaminated water and the level sensor 400 adjusts its automatic positioning based on the measurements made and of the upper L2 and lower L1 values. Based on the information from the level 400 sensor, the mobile device 20 is automatically positioned so as to stay around the normal operating level Lopt. The phase sensor 500, when detecting the water phase, determines the disengagement of the mobile device 20 from the body of water; the phase sensor 501, when it detects demixed organic phase 40, determines the immersion of the mobile device 20 for re-starting the filtering operations.

[0103] Consequently, in a preferred configuration, the automatic process for removing a demixed organic phase 40 which extends from a lower interface surface WO with a heavier phase to an upper interface surface GO with a lighter phase in the body of the contaminated water also comprises the phases of: [0104] o) lifting the mobile device 20 with a slow vertical velocity Vl until its complete disengagement from the liquid phase based on the information from the phase sensor 500, when the phase sensor 500 does not detect the demixed organic phase 40; [0105] pp) keeping the mobile device (20) stationary in the fully disengaged position of the liquid phase when the second phase sensor 501 does not detect the presence of the demixed organic phase 40; [0106] r) repeating phases d) to g) for a number of times.

[0107] The apparatus 10, for removing a demixed organic phase 40 in a contaminated water body, of the present invention as conceived is susceptible in every case to numerous modifications and variants, all of which fall within the same inventive concept; Moreover, all details can be replaced by technically equivalent elements. In practice, the materials used, as well as the shapes and the sizes, may be any according to the technical requirements.

[0108] The scope of protection of the invention is therefore defined by the appended claims.