HK1157733B - Apparatus for purifying liquids, in particular ballast water - Google Patents

Description

Device for purifying liquids, in particular ballast water

Technical Field

The present invention relates to a device for purifying liquids, in particular ballast water.

Background

The ballast water is carried by the marine vessel to stabilize the vessel and ensure its seaworthiness during airborne driving. For this purpose, seawater or river water is contained in special ballast tanks or, in the case of double hulls as is common today, in a cavity between the two hull walls of the hull. By taking ballast water at a first location and releasing the same ballast water at a second location, it is often the case that organic organisms are spread into foreign ecosystems (invasive species problem).

To compensate, marine vessels are often equipped with coarse mechanical filters for filtering the contained ballast water. The disadvantage here is that filters, for example consisting of a pipeline network grid, require regular maintenance and cleaning.

In some cases, the ballast water may be stored for several weeks to some extent, and sterilized by ultraviolet rays during its discharge. It is disadvantageous here that, for example, young animals or larvae are introduced into the ballast water tank, where organisms such as fish or crabs can develop into adult animals, which survive the uv treatment relatively intact. Furthermore, the microbial and algal flora has increased to some extent over a large number of weeks, requiring high uv intensity resulting in high energy consumption. Instead of the ultraviolet treatment, the ballast water is treated with chlorine in some cases. However, the release of strongly chlorine-contaminated water also represents a very significant intervention in the local ecosystem.

Therefore, the most advanced methods and devices for ballast water purification are known to also provide only low flexibility, reliability and/or environmental safety when treating ballast water. Furthermore, the known methods and devices for ballast water treatment require relatively high maintenance expenditure and do not provide adequate protection against biological transmission in foreign ecological systems.

Disclosure of Invention

It is therefore an object of the present invention to provide a device for purifying liquids, in particular for purifying ballast water, which can be operated reliably at low cost and with high flexibility and which ensures a sufficient degree of purification of the stored liquid.

This object is solved by a combination of the features according to claim 1. Preferred embodiments are described in the appended claims.

The device according to the invention for the purification of liquids, in particular for the purification of ballast water, comprises at least two filter modules and a reactor with at least one uv source. Each filter module comprises an inlet for liquid to be purified, a first outlet, a filter, and a second outlet for purified liquid, wherein for liquid input in the filter module the first outlet is arranged before the filter and the second outlet is arranged after the filter. Thus, the first outlet and the second outlet are arranged on different sides of the filter.

Thus, liquid to be purified, which is fed into the respective filter module via the inlet, can flow out of the filter module via the first outlet without passing through the filter. The liquid to be purified, which is input through the inlet, may pass through the filter and leave the filter module through the second outlet.

The reactor of the device is connected to the first outlet by a first line, through which a first flow can be directed to the reactor. The reactor is connected to the second outlet by a second line through which the second flow can be directed to the reactor. In addition, the reactor is adapted to expose both the first and second flow rates to radiation from the ultraviolet source.

The advantageous effect of this device is its high flexibility, in particular in the following three possibilities for purifying liquids, in particular ballast water:

first, the device allows the liquid to be purified to flow unfiltered out of the filter module through the first outlet and subsequently be supplied to the (only) uv treatment at a first flow rate.

Furthermore, the device allows the liquid to be purified to be freed from animals, organisms and other particular objects of a particular size by filtration in the filter module before subsequent UV treatment. Thus, the direct (spatial as well as temporal) subsequent uv treatment is not burdened, so that the purification can be run with lower energy costs.

Furthermore, in a third possibility, the advantageous effects of the other two possibilities can be combined: in a first flow, part of the liquid to be purified, which leaves the respective filter module through the first outlet, reaches the reactor and is treated therein with uv light. At the same time, in the second flow rate, the remaining flow rate of the liquid to be purified, which flows out of the respective filter module through the second outlet, can be conducted to the reactor in the form of the second flow rate and treated separately from the first flow rate by means of uv light.

By providing separate flow rates, the contact time for example for each flow rate to be exposed to ultraviolet radiation can be flexibly and independently adjusted to each other. It is thus possible to flexibly treat the liquid to be purified in the first flow rate and/or the second flow rate depending on the degree of impurities and/or the degree of purity of the liquid to be achieved.

Preferably, the first flow rate and the second flow rate are directed through the reactor independently of each other. Preferably, the first and second flow rates are delivered to the uv source of the reactor separately as close as possible.

In a preferred embodiment, the second outlets are connected to each other by a backflush line, so that backflushing of the filters of one filter module can be performed using the filtered liquid of the other filter module. The advantageous effect of the device is mainly that during operation, the backflushing of one filter module can take place while the other filter modules continue to function normally. Thus, reliable continuous operation is possible.

Preferably, the inlet of each filter module has a valve. Preferably, the first outlet of each filter module has its own valve. Controlled and flexible regulation of the input and output flows in the individual filter modules is possible. For backflushing of the filters of the above one filter module, its feed valve is closed and the valve of its first outlet is opened. Furthermore, each second outlet may be provided with a controllable valve.

Preferably, the apparatus is arranged to direct liquid backflushed through the filter of one filter module to the reactor at a first flow rate through the first line. The device according to the invention thus has the advantageous effect that the backflushing liquid is conducted through the reactor separately via the first line and can be exposed to a separate treatment compared to the filtered liquid, which can flow to the reactor via the second line.

Preferably, the device has a first reservoir for storing the liquid to be purified, the first reservoir being connected to the inlet. Furthermore, it is particularly preferred that the device has a second container arranged in the first line, the second container being suitable for a buffer liquid. Thus, the (backflush) liquid may be buffered and guided through the reactor at, for example, a very low throughput rate, thereby increasing the contact time of the backflush liquid (i.e. the strongly contaminated and infected liquid).

Further, it is particularly preferred that the reactor further comprises an ultrasonic source for applying ultrasound to the first and second flow rates. The cavitation effect caused by ultrasound can damage and kill microorganisms and other organic/inorganic substances not dissolved or suspended in the liquid to be purified, which were not removed in the previous filtration. The achievable degree of liquid purification and the performance of the device are thus further improved, as is the flexibility of the overall device.

In a particularly preferred embodiment, the reactor comprises an inlet opening into the interior of the reactor and an outlet opening out of the interior of the reactor. Preferably, the uv source and/or the ultrasound source are arranged inside the reactor. In addition to the purification of the inflowing liquid, the admission of ultrasound into the interior of the reactor ensures continuous purification of the surfaces of any precipitate in contact with the liquid, and therefore reliable continuous operation.

In a preferred embodiment, the second line is connected to the inlet of the reactor such that the second flow passes through the inlet, into the reactor interior and out of the reactor interior through the outlet. Depending on the size of the reactor, it may be achieved that the filtered liquid passes through the reactor interior at a relatively high passage rate. Particularly preferably, the reactor also comprises a liquid line which passes through the reactor interior, in particular the liquid line is closed in a liquid-tight manner from the reactor interior in the reactor interior. The liquid line thus provides the possibility of conducting the flow of the liquid to be purified through the reactor interior, isolated from the reactor interior, and does not allow the liquid to be purified to come into direct contact with the reactor interior or with the liquid present therein, respectively.

For this purpose, it is particularly preferred that the liquid line through the reactor is connected to the first line, through which the first flow flows through the interior of the reactor. Thus, it is ensured that the first flow is separated from the second flow through the reactor interior and guided past the uv source and optionally past the ultrasound source, so that a separate treatment of the first flow and the second flow is possible, so that a mixing of the first flow and the second flow in the reactor is avoided.

Particularly preferably, the liquid line is composed of a material which is transparent to ultraviolet rays. In particular, the liquid line may comprise one or more quartz tubes.

In particular, the quartz tubes may be placed in parallel. Alternatively, the quartz tubes may be connected to each other to be placed in series. In the case of quartz tubes placed in parallel, there is an advantageous effect in that a relatively high throughput rate can be achieved. In the case of quartz tubes placed in series, the advantageous effect is that the liquid as it flows through the quartz tubes and through the interior of the reactor is subjected to a plurality of purifications.

Preferably, the reactor is also traversed by at least one quartz tube, in each of which an ultraviolet source is arranged.

In a particularly preferred embodiment, the filter of each filter module comprises a membrane. Preferably, each filter module further comprises an ultrasound source for irradiating the membrane with ultrasound. To this end, the membrane is formed of a material capable of withstanding ultrasonic treatment, such as stainless steel or other metal alloys. By irradiating the membrane with ultrasound during operation and backflushing, clogging of the membrane by sediment is avoided. Preferably, the ultrasound source for the liquid flowing into the filter module is arranged in front of the filter, i.e. on the side of the filter which is usually more contaminated.

The membrane may have pores of less than 1000 μm, preferably less than 100 μm, most preferably less than 50 μm. In the case of ballast water, it is advantageous if the pore size is at most about 30 μm. For microfiltration, pores with pore sizes down to 0.1 μm may be used.

In particular, the device may also comprise more than two filter modules, which are connected to one another in the manner described above for backflushing.

Furthermore, two filter modules (each) may be connected in series with each other, the first outlet of the (each) first filter module being connected with the inlet of the (each) second filter module. In particular, in the case of strong contamination, the liquid to be purified can be pre-purified in a first filter module and main purification/filtration in a second filter module.

Particularly preferably, the entire plant is suitable for the treatment of brackish water, in particular seawater.

In particular, one application of the above-described device for liquid purification according to the invention is the treatment of ballast water. Thus, each of the filter modules may be backflushed in turn.

Drawings

Further features and advantages of the invention will be described in the following description of embodiments with reference to the drawings and in the claims.

Fig. 1 shows a schematic view of a device for liquid purification according to the invention;

FIG. 2 shows a detailed view of an embodiment of the device according to the invention;

3-7 illustrate the use of the embodiment of the apparatus according to the invention shown in FIG. 2 in the treatment of ballast water;

fig. 8 shows an embodiment with filter modules aligned in pairs in series.

Detailed Description

Fig. 1 schematically shows an embodiment of a device for liquid purification.

The device 100 comprises two filter modules 10, each having the shape of a hollow cylinder and consisting of a stainless steel tube closed at both ends. At the upper end of each filter module an inlet 12 for the liquid to be purified is provided, and at the lower end a first outlet 14 for the liquid is provided. In addition, a second outlet 16 is provided in the duct housing of the filter module 10 near the upper end of the module.

A stainless steel membrane with pores of about 30 μm was provided inside the filter module 10. The stainless steel membrane 18 also has the shape of a hollow cylinder, which is arranged substantially coaxially (i.e. concentrically in cross-section) in the stainless steel tube of the filter module 10, wherein the diameter of the stainless steel membrane is smaller than the diameter of the filter module 10. The inlet 12 and the first outlet 14 are disposed about midway between the rounded upper or lower ends (i.e., the lid or bottom, respectively) of the filter module 10. Thus, liquid flowing into the interior of the filter module 10 via the inlet 12 can flow out of the filter module 10 via the outlet 14 without passing through the cylindrical filter membrane 18. In this sense, the first outlet 14 is therefore arranged before the filter membrane 18. In contrast thereto, liquid flowing into the filter module 10 via the inlet 12 can only flow out of the filter module 10 via the second outlet 16 if it has previously passed through the filter membrane 18. In this sense, each second outlet 16 is located after the filter membrane 18.

The two second outlets 16 are connected to each other by a back flush line 20 for exchanging liquid.

As shown in fig. 1, each filter module 10 is connected at its upper end by an inlet 12 to a liquid supply 30, which liquid supply 30 is supplied by a first container 32 (not shown in fig. 1, see fig. 2) in the form of a ballast water tank.

At the other end, each filter module 10 is connected to a first line 34 through a first outlet 14. In the first line 34, a second container 36 is provided as a buffer for the liquid.

The first line 34 leads to an elongated reactor 40, the reactor 40 surrounding a reactor interior 41. The reactor interior 41 is traversed longitudinally by a liquid line 42 consisting of a quartz tube. Further, an elongated UV source 44 extends within reactor interior 41, UV source 44 being disposed substantially parallel to the longitudinal axis of reactor 40 like a quartz tube. The first line 34 opens into a quartz tube-shaped liquid line 42 at the longitudinal lower end of the reactor 40. At the other end of the reactor 40, a liquid line 42 leads out of the reactor interior 41 into another liquid line, for example made of quartz or glass fibers. Although only a straight run is shown in the figures, a spiral or spirally interlaced configuration is conceivable, in particular for the liquid lines 42, in which, for example, each liquid line 42 surrounds the uv source 44 arranged in a quartz tube at an absolutely close distance (not shown).

The reactor 40 has a substantially hollow cylindrical shape with an inlet 46 near the lower end and an outlet 48 near the upper end of its shell surface. The second outlet 16 of the filter module 10 is connected via a second line 50 to the inlet 46 into the reactor interior 41.

Furthermore, each filter module 10 is provided with a substantially rod-shaped ultrasound source 60, the ultrasound source 60 being arranged slightly offset (i.e. eccentric) to its longitudinal axis in the hollow cylindrical shape of the filter module 10. In the same way, an eccentric ultrasound source (not shown) is arranged in the reactor interior 41. Each ultrasonic source provides for the purification of the liquid and the purification of the filter module 10, in particular the filter 18 or the reactor 40.

Further details of the apparatus 100 and the function and effect of the elements of the apparatus 100 will be described separately and jointly with respect to fig. 2-7.

Fig. 2 shows an embodiment of the apparatus 100 used as a device for purifying ballast water. As shown in fig. 2, a ballast water pump 70 is provided in the liquid supply 30 to pump water from the sea or from the ballast tank 32 into the inlet 12 of the filter module. Each inlet 12 of the four filter modules 10 as shown includes a water inlet valve 72 for controlling the amount of inflow into the respective filter module 10. In addition, each first outlet 14 has a valve 74 for controlling the flow of liquid out of the first outlet 14. Furthermore, the embodiment as shown in fig. 2 has a first bypass line 76 and a second bypass line 78. The first bypass line connects the liquid supply 30 with the second line 50. Thus, with the water inlet valves 72 of all filter modules 10 closed, the liquid to be treated can be directed by-pass into the reactor 40 without being filtered. A second bypass line 78 connects the liquid supply 30 with the liquid line connected to the outlet 48 of the reactor 40. With the inlet valves 72 of all the filter modules 10 closed and the first bypass valve 77 provided in the first bypass 76 closed, the liquid does not flow through the filter modules 10 or the uv reactor 40 but is pumped back to the sea.

As shown in FIG. 2, the reactor 40 has a cavitation chamber 80 at its lower end, the cavitation chamber 80 having a smaller diameter than the upper portion of the reactor 40, and the liquid inlet 46 of the reactor 40 opens into the cavitation chamber. In the reactor interior 41, a rod-shaped ultrasound source 82 extends throughout the entire length of the reactor 40, i.e. through the cavitation chamber 80 and the upper part of the reactor 40 connected thereto, the ultrasound source being arranged slightly offset from the longitudinal axis of the reactor 40, i.e. eccentrically in the sectional view. In addition, two quartz tubes, one uv source 44 per quartz tube as shown in fig. 2, pass through the reactor interior 41 (not shown in fig. 2) at the upper portion of the reactor 40. The reactor interior 41 is penetrated by the other two quartz tubes 84 constituting the liquid line 42, and the lower end of one quartz tube 84 is connected to the first line 34. The other end of the quartz tube 84 is connected to the corresponding end of the second quartz tube 84 by a tube connector 86. Thus, liquid, such as highly contaminated backwash liquid, passing through the first line 34 to the reactor 40 may be guided twice through the reactor interior 41, i.e., during the ascent in the first quartz tube 84 and the descent through the second quartz tube 84. During each passage through the interior of the housing, the liquid is exposed to ultraviolet radiation because the quartz is ultraviolet radiation-permitting, and likewise, the liquid is subjected to ultrasound because the quartz tube transmits ultrasound to the liquid flowing through the tube. Thus, a very efficient purification of the first flow through the first line 34 to the reactor can be ensured. Depending on the number of quartz tubes 84 arranged in series, various treatments of the liquid may be achieved, depending on the number of quartz tubes 84 arranged. The present invention is not limited to two quartz tubes 84 and may include any number of quartz tubes 84 depending on the results to be achieved. In addition, purification may be enhanced by the spiral or helical intermesh configuration of liquid lines 42 described above, wherein lines 42 surround one UV source 44 in the form of quartz tube 84.

A second flow (main flow) flows into the reactor interior 41 through the second line 50 and the inlet 46 into the cavitation chamber 80 of the reactor 40. In the cavitation chamber 80, the second flow of input liquid is fully exposed to ultrasound from an ultrasound source 82. The second flow in the interior of the reactor flows from the inlet 46 to the outlet 48 and thus from the cavitation chamber 80 into the upper portion of the reactor 40. In this upper portion, the second flow is again exposed to ultrasound and also to uv radiation from a uv source 44 disposed in the quartz tube. The second flow then exits the reactor 40 through the outlet 48 and is injected into the recycle line 90. The first flow that has passed through the quartz tube 84 is also injected into the recirculation line 90 through the injector nozzle. The first and/or second flow of the respective treated purified liquid is passed through the recirculation line 90 either back to the ballast tank 32 or into the ocean (according to the adjustment of the valve located in the recirculation line 90 as shown in fig. 2).

Fig. 3 shows an embodiment of the apparatus 100 during ballast water loading.

The inlet valves 72 of the first three (left-hand) filter modules 10 as shown in fig. 3 are fully open. Furthermore, the valves 74 of the first outlets 14 of the first three filter modules 10 are each at least partially open. The inlet valve 72 of the fourth filter module 10, i.e. the filter module on the right, and the valve 74 of the first outlet are both closed. The ballast water pump 70 ensures that water from the ocean reaches each of the first three filter modules 10, as indicated by the arrows of the arms leading to the ocean's liquid supply 30. In each of the first three filter modules 10, a first portion of the water reaching the lower end of the filter module does not pass through the filter 18, passes through the first outlet 14 of each filter module 10, and larger objects and organisms present in the water in the first portion of the water are flushed from each filter module 10 back to the ocean by branching off of the first line 34 shown in fig. 3. A second portion of the water entering each filter module 10 passes through the filter 18 and through each second outlet 16 and second line 50 to the interior of the reactor 40. In the interior 41 of reactor 40, the liquid is irradiated by ultrasound from ultrasound source 82 (after the liquid has been exposed to ultrasound from ultrasound source 60 in filter module 10) and by ultraviolet radiation from ultraviolet source 44 (not shown in fig. 3). Water flowing through outlet 48 flows from reactor interior 41 into ballast water tank 32 through recirculation line 90. The water contained and directed into the ballast water tank 32 is filtered, disinfected and purified using ultraviolet radiation and ultrasound.

In fig. 4, an embodiment of the device 100 is shown during circulation of the water present in the ballast water tank 32.

Of the four filter modules 10 shown, three on the right are connected to the supply 30 (i.e., each feed valve 72 is open) and are in a filtering operation. The left filter module 10 is disconnected (the water inlet valve 72 is closed) and in a purification mode, wherein the filter module is filled with water which is treated by ultrasound from the ultrasound source 60 for purification of the filter membrane 18.

Water from the ballast tank 32 is led by means of the ballast water pump 70 to the three filter modules 10 on the right, where it is filtered. The filtered water then flows accordingly into the reactor 40 where it is exposed to ultrasonic and ultraviolet treatment. The purified water flows back to the ballast water tank 32 through the recirculation line 90.

Alternatively, in the embodiment shown in fig. 4, the filter module 10 may be bypassed by a bypass valve 77, using only reactor 40 for sterilization.

Fig. 5 shows an embodiment of the device 100 during purification of water from the ballast water tank 32, similar to the purification according to fig. 4.

As in the embodiment according to fig. 4, the filter module 10 on the right is in the filtration mode and the filter module 10 on the left is in the cleaning mode. Fig. 5 shows the backflushing of the first filter module 10. In contrast to fig. 4, the valve 74 of the first outlet 14 of the first filter module 10 (i.e. the filter module on the left) is at least partially open, so that filtered liquid flows through the second outlet 16 of the first filter module 10 via the backflush line 20, which is shown as connecting the second outlets 16 of the four filter modules, back through the filter membranes 18 of the first filter module 10, and back into the ocean via the first outlet 14 of the first filter module 10. Optionally, the backwash liquid may also be directed to reactor 40 via line 34 and through reactor interior 41 via liquid line 42 to provide additional purification for the backwash water (as shown in fig. 7) if the level of purification is not sufficient to be immediately discharged back to the sea. Thus, the second container 36 may act as a buffer for the back flush volume of water, such that the back flush may be directed through the interior 41 of the reactor 40, for example, with a lower throughput rate and longer contact time.

Fig. 6 shows an embodiment of the apparatus 100 during purification and subsequent discharge of ballast water from the tank 32 back to the ocean.

In addition, water from the tank 32 is pumped by a pump 70 into the three filter modules 10 located on the right. If the valve 74 of each first outlet 14 of the three modules located on the right is closed, the ballast water passes through each filter membrane 18 and through the second line 50 to the reactor interior 41. After treatment with ultraviolet and ultrasound in the reactor interior 41, the ballast water exits the reactor through the second outlet 16 and outlet 48 and may be discharged into the ocean as purified water.

Fig. 7 shows an embodiment of the apparatus 100 during discharge of stored ballast water and simultaneous backflushing of the filter module 10.

As shown, three of the four filter modules 10 from the right are in the filtration mode, while the left filter module 10 is disconnected from the supply 30 and is in the backflush mode. By means of the first line 34 and the second container 36 arranged therein, the backwash water reaches the reactor 40 as a first flow through the first module and is guided twice through its interior 41 and purified as described above by means of the liquid line 42 consisting of two quartz tubes 84. The filtered water from the three modules located on the right reaches the reactor 40 through the second line 50 and flows immediately into and through its interior 41, so that this second flow is purified.

Thus, the first flow of backwash water from the first filter module 10 and the second flow of filtered water from the other three filter modules 10 are separated from each other and sterilized in the reactor 40 due to the different flow rates, and then discharged to the sea without any problems.

Fig. 8 shows other embodiments of the device 100. The first (left-hand) filter module has a branch 92 from the first outlet. This branch 92 is connected to the inlet 12 of the second (left-hand) filter module, so that unpurified liquid from the first filter module can be treated and purified in the second filter module. The third and fourth filter modules are arranged in series in the same manner.

By using valves 74, 74' as shown in fig. 8, liquid passing through the first outlet may be directed to the first line 34 and/or through the branch 92.

Furthermore, the inlet of the second filter module may also be connected to the liquid supply by an optional line with a valve 72'. The apparatus 100 shown in fig. 8 may also operate as described above with respect to fig. 1-7 when the valve 74' is closed.

The features disclosed above, the claims and the drawings can be combined independently and arbitrarily, the different embodiments of which are important for the realization of the invention.

Claims (27)

1. Apparatus for purifying a liquid, comprising:

at least two filter modules (10); and

a reactor (40) with at least one UV source (44),

wherein each filter module (10) comprises an inlet (12) for liquid to be purified, a first outlet (14), a filter (18), and a second outlet (16) for filtered liquid, wherein for liquid input through the inlet (12), the first outlet (14) is arranged before the filter (18), the second outlet (16) is located after the filter (18),

wherein the reactor (40) is connected with the first outlet (14) by a first line (34) and with the second outlet (16) by a second line (50), and

wherein the reactor (40) is adapted to expose a first flow to the reactor (40) through the first line (34) and a second flow to the reactor (40) through the second line (50) to UV light from the UV light source (44).

2. The apparatus of claim 1, adapted to separately direct the first flow and the second flow through the reactor.

3. The device according to claim 1, wherein the second outlets (16) are connected by a backflush line (20) such that backflushing of the filters (18) of a filter module (10) can be performed by filtered liquid from other filter modules (10).

4. The apparatus of claim 1, wherein the inlet (12) of each filter module (10) comprises a water inlet valve (72).

5. The apparatus of claim 4, wherein the first outlet (14) of each filter module (10) comprises an output valve (74).

6. A device according to claim 5, wherein the second outlets (16) are connected to each other by a backflush line (20) such that backflushing of the filters (18) of one filter module (10) can be performed by filtered liquid of another filter module (10) when the inlet valve (72) of the inlet (12) of one filter module (10) is closed and the outlet valve (74) of the first outlet (14) of one filter module (10) is open.

7. An apparatus according to claim 3, adapted to direct backflushing liquid as a first flow rate by the filter (18) of one filter module (10) through the first line (34) to the reactor (40).

8. The device according to claim 1, further comprising a first container (32) for storing the liquid to be purified, the first container (32) being connected to the inlet (12) of the filter module (10).

9. The device according to claim 8, further comprising a second container (36), said second container (36) being arranged in said first line (34) and being adapted for buffering a liquid.

10. The device according to claim 8, further comprising a second container (36), said second container (36) being arranged in said first line (34) and being adapted to buffer the backflushing liquid.

11. The apparatus of claim 1, wherein the reactor (40) further comprises an ultrasound source (82) for exposing the first and second flows to ultrasound.

12. The apparatus of claim 1, wherein the reactor (40) comprises an inlet (46) to the interior (41) of the reactor (40), and an outlet (48) out of the interior (41) of the reactor (40).

13. The apparatus of claim 11 wherein said ultraviolet source (44) and said ultrasound source (82) are disposed within said reactor (40).

14. The apparatus of claim 12, wherein the second line (50) is connected to the inlet (46) of the reactor such that the second flow can flow into the interior (41) of the reactor (40) through the inlet (46) and can flow out of the interior of the reactor (40) through the outlet (48) of the reactor.

15. The apparatus of claim 1, wherein the reactor (40) comprises a liquid line (42) passing through the interior (41) of the reactor (40) and being closed in the interior (41) of the reactor (40) with respect to the interior (41) of the reactor (40).

16. The apparatus of claim 15, wherein the liquid line (42) is connected with the first line (34) such that the first flow flows through the interior (41) of the reactor (40) through the liquid line (42).

17. The device of claim 15, wherein the liquid line (42) is constructed of a material that is ultraviolet transparent.

18. The apparatus of claim 15, wherein the liquid line (42) comprises one or more quartz tubes (84) passing through the interior (41) of the reactor (40) and arranged in parallel or in series.

19. Apparatus according to claim 1, wherein the interior (41) of the reactor (40) is traversed by at least one quartz tube, wherein the or each uv source (44) is arranged in the quartz tube, respectively.

20. The apparatus of claim 1, wherein the filter (18) of each filter module (10) comprises a membrane.

21. The apparatus of claim 1, wherein each filter module (10) comprises an ultrasound source (60) for irradiating the filter (18) with ultrasound.

22. The device according to claim 1, wherein the filter (18) has pores smaller than 100 μm.

23. The device according to claim 1, wherein the filter (18) comprises pores as small as 0.1 μm.

24. The apparatus of claim 1, wherein the apparatus is adapted to purify ballast water.

25. The device according to claim 1, wherein two filter modules (10) are connected in series by connecting the first outlet (14) of a first filter module to the inlet (12) of a second filter module.

26. Use of a device according to any one of the preceding claims for treating ballast water.

27. Use of a device according to any one of the preceding claims for treating ballast water, wherein each filter module (10) is backflushed in succession.