WO2025254528A1

WO2025254528A1 - A method for the removal of microfibers and nanofibers from laundry wastewater

Info

Publication number: WO2025254528A1
Application number: PCT/NL2025/050277
Authority: WO
Inventors: Emmanouil CHATZIGIANNAKIS
Original assignee: Eindhoven Technical University
Current assignee: Eindhoven Technical University
Priority date: 2024-06-07
Filing date: 2025-06-06
Publication date: 2025-12-11
Anticipated expiration: 2026-12-07

Abstract

The present invention relates to a method for the removal of microfibers and nanofibers from laundry wastewater. The present invention also relates to an apparatus for the removal of microfibers and nanofibers from laundry wastewater and to a laundry machine provided with such an apparatus. An object of the present invention is to provide a method for the removal of microfibers and nanofibers from laundry wastewater in which the fibers can be disposed of as regular household waste.

Description

Title: A method for the removal of microfibers and nanofibers from laundry wastewater

Description:

The present invention relates to a method for the removal of microfibers and nanofibers from laundry wastewater. The present invention also relates to an apparatus for the removal of microfibers and nanofibers from laundry wastewater and to a laundry machine provided with such an apparatus.

Microplastics, defined as plastic particles under 5 mm, pose a significant environmental and health threat. Nanoplastics are extremely small plastic particles, typically defined as being smaller than 1 micrometre in size. These particles are even smaller than microplastics and are of increasing concern due to their potential to cause harm to the environment and health.

These micro plastic particles and nano plastic particles have infiltrated various ecosystems, including rivers and oceans, impacting marine life, and posing risks to human health. Consequently, addressing microplastic pollution has become an urgent priority. They can absorb toxins, be ingested by aquatic and terrestrial organisms, and enter the food chain, potentially impacting wildlife, and human health. Microfibers from synthetic clothing are a major contributor to this contamination, generated during laundering and ending up in aquatic environments. Microplastics have been found in virtually every ecosystem on Earth, from the peaks of mountains to the depths of the oceans. They are present in freshwater systems, marine environments, soil, and even airborne dust. Numerous species, including fish, birds, marine mammals, and invertebrates, ingest microplastics either accidentally or because the plastics are mistaken for food. Once ingested, these particles can cause physical harm, such as blockage of the digestive tract, or reduce the urge to eat, leading to malnutrition or starvation. Microplastics can attract and concentrate surrounding pollutants, such as pesticides, heavy metals, and persistent organic pollutants from the environment. The ingestion and accumulation of microplastics in the bodies of various organisms can lead to reduced reproductive success and increased mortality rates, impacting biodiversity. Humans can ingest microplastics through contaminated seafood, water, and even from the air. There is concern that these particles could contribute to inflammation, carry toxic contaminants, or even penetrate tissues and organs. Microplastics are increasingly being found in soil environments, particularly through the application of sewage sludge as fertilizer and the degradation of plastic mulch used in agriculture. Efforts to mitigate the environmental impact of microplastics include improving waste management practices, reducing plastic use and production, developing biodegradable alternatives, and enhancing public awareness and policy regulations aimed at plastic pollution control.

Korean application KR20220078989A relates to a washing machine filter for the reduction of microplastics using microbubbles. The washing machine drainpipe is formed in a cylindrical shape to allow sewage from the washing machine to pass through, and the upper part can be blocked to allow water to pass through the washing machine drainpipe to filter nm-sized microplastics coming from the laundry. A filter is installed to block the upper part of the washing machine drainpipe so that water can still pass through it, so that nm-sized microplastics from laundry can be filtered through a HEPA filter.

International application WO2023160755 relates to a fully automatic washing machine having an electrically driven fluid pump wherein the wash liquid contaminated with microplastic particles is actively filtered. A drain pump is operated, and a multiway valve is switched so that the wash liquid is conveyed to the filter device via a filter line. In addition, a brushless DC electric motor (BLDC) motor of the filter device is activated and in this way a filter insert rotates in the filter housing.

Chinese publication CN212102085 relates to a flotation device for separating microplastics in water, comprising a flotation mechanism, wherein the flotation mechanism comprises a reaction container, an air bag, and an air intake assembly. The reaction container contains a sample water body and is provided with a discharge port, wherein the air intake assembly is connected to the air bag. When a flotation agent is added to the sample water body of the reaction container, microplastics in the sample water body float to the water surface, wherein a collecting mechanism comprising a linear drive assembly and a scraper is used to drive the scraper to pass through the water surface for scraping the microplastics into a sample cup.

Recognizing the adverse effects of smaller microplastics and nanoplastics, there is a critical need to enhance the efficiency of such removal systems. This is however not feasible through the conventional route of filtration, because reducing the pore size in the incorporated membranes causes clogging and significant malfunctions. Moreover, the economic feasibility of these technologies is questionable as the regular replacement of filters adds to the operational costs, hindering implementation in settings such as laundromats and the textile industry.

As discussed, devices based on filtering have limitations. The minimum size of the microfibers that can be separated is set by the pore size of the filter. Reducing however the size of the pores is possible but considerable pressure drops will be generated, which will cause malfunctions in the laundry machine itself. Therefore, commercial filtering devices have a minimum microfiber size that can be separated of 30pm or larger. This will have the negative consequence that smaller microfibers and nanofibers will pass through and end up in aquatic environments.

Another approach is the use of washing bags. Such washing bags use the same filtering technology as mentioned above and are thus unable to capture the smaller microfibers and nano-fibers. In addition, the larger, yet also hazardous, microfibers trapped inside the washing bag have to be disposed of.

An object of the present invention is to provide a method for the removal of microfibers and nanofibers from laundry wastewater in which the fibers can be disposed of as regular household waste.

Another object of the present invention is to provide an apparatus for the removal of microfibers and nanofibers from laundry wastewater.

The present invention as mentioned above relates to a method for the removal of microfibers and nanofibers from laundry wastewater, the method comprising the following steps: providing a flow of laundry wastewater comprising microfibers and nanofibers, formation of a foam phase rich in microfibers and nanofibers, separating of the foam phase rich in microfibers and nanofibers from a flow of laundry wastewater depleted of microfibers and nanofibers.

On basis of the above method one or more objects are achieved.

In an example the formation of the foam phase comprises infusing the flow of laundry wastewater comprising microfibers and nanofibers with a gaseous phase thereby creating bubbles in the laundry wastewater.

In an example the infusion takes place via a continuous flow of compressed air or carbon monoxide. In another example the formation of the foam phase takes place by agitating the laundry wastewater comprising microfibers and nanofibers mechanically thereby creating bubbles in the laundry wastewater.

In an example infusing the flow of laundry wastewater comprising microfibers and nanofibers further comprises passing the gaseous phase through a porous element before the gaseous phase enters the flow of laundry wastewater.

In an example the formation of the foam phase comprises a combination of one or more of infusing the laundry wastewater with the gaseous phase and agitating the laundry wastewater.

In an example the foam phase rich in microfibers and nanofibers is further separated into at least a stream comprising laundry wastewater and a stream comprising microfibers and nanofibers.

In an example the stream comprising microfibers and nanofibers is further treated for isolating the microfibers and nanofibers from the stream comprising microfibers and nanofibers, the step of further treating comprises a drying step.

The present invention also relates to a method for washing clothes in a washing machine, wherein clothes are brought into contact with water and detergents and a flow of laundry wastewater comprising microfibers and nanofibers is formed, the method further comprising a method for the removal of microfibers and nanofibers from the laundry wastewater as discussed above.

Furthermore, the present invention relates to an apparatus for the removal of microfibers and nanofibers from laundry wastewater comprising: a container having an inlet for laundry wastewater, an outlet for laundry wastewater, a gaseous phase infusion assembly configured to infuse laundry wastewater passing from the inlet to the outlet with the gaseous phase thereby producing a foam phase, and an outlet for the foam phase.

In an example the gaseous phase infusion assembly comprises a gaseous phase inlet for a gaseous phase inflow.

In an example the gaseous phase infusion assembly further comprises a porous element in communication with the gaseous phase inlet.

In an example an average diameter of the pores is at least 0.1 pm, preferably at least 0.2 pm. In some embodiments, the pores of the porous element decrease in size from the inlet to the outlet. In some embodiments, the average diameter of the pores is no more than 1 mm.

In an example the infusion assembly comprises a mixing device, such as at least one stirring member.

In an example the infusion assembly comprises a mixing device comprising at least one of a porous member and a stirring member disposed at an inlet of a gaseous phase inflow.

In an example the infusion assembly comprises a mixing device comprising at least one of a porous member and a stirring member.

In an example the mixing device is disposed at a gaseous phase inlet for a gaseous phase inflow.

In an example the infusion assembly comprises a combination of one or more of an inlet for a gaseous phase inflow, a mixing device, and a porous element.

In an example the gaseous phase infusion assembly is disposed at a top portion or at a bottom portion of the container, while the outlet for the foam phase is disposed at a top portion of the container.

In an example the apparatus further comprises a foam collection compartment in fluid communication with the outlet for the foam phase.

In an example the apparatus further comprises a foam drying assembly in fluid communication with the foam collection compartment.

In addition, the present invention relates to a laundry machine provided with an apparatus for the removal of microfibers and nanofibers from laundry wastewater as discussed above.

The method of the present invention will be better understood by referring to the following detailed description of preferred embodiments and the drawings referenced therein, in which:

FIG. 1 illustrates one embodiment of the apparatus of the present invention.

FIG. 2 illustrates another embodiment of the apparatus of the present invention.

FIG. 3 illustrates another embodiment of the apparatus of the present invention.

FIG. 4A-4C illustrate front views of different embodiments of the apparatus of the present invention. FIG. 5A-5B illustrate in further detail a stirring member according to an embodiment of the present invention.

FIG. 6A-6B illustrate in further detail a stirring member according to an embodiment of the present invention.

FIG. 7A-7B illustrate in further detail a stirring member according to an embodiment of the present invention.

The present inventor found that introducing flotation as a separation method is an effective way in capturing particles, such as microfibers and nanofibers, with bubbles. In particular, 60% separation efficiency, and in some cases 80%, is expected to be achieved with embodiments described here, especially the embodiments illustrated in figures 1-3. For example, where the input laundry wastewater contains 200,000 microfibers/liter water, the output is expected to contain as little as 40,000 microfibers/liter water. The present inventor found that the pressure drop between the inlet and the outlet of the apparatus according to the present invention does not increase more than 20% after 60 washing cycles.

The present method utilizes the inherent surface activity of microplastics and residual detergents for their removal. According to the present method bubbles are continuously generated for capturing microfibers of all sizes. The resulting wet foam, which is rich in microfibers and nanofibers, is efficiently removed and collected in another compartment, thereby preventing microfibers and nanofibers from entering the environment and enabling, after in-situ draining, their disposal as regular household waste.

Microfibers can be defined as any natural or artificial fibrous materials of threadlike structure. Microfibers typically have a length ranging from 1 pm to 5 mm and a length to diameter ratio greater than 10. Nanofibers can be defined as any natural or artificial fibrous material of threadlike structure typically having a length in a range of 100 nm to 1 pm and a length to diameter ratio greater than 10.

Figure 1 illustrates an apparatus for the removal of microfibers and nanofibers from laundry wastewater. Container 1 has an inlet for laundry wastewater 3, an outlet for laundry wastewater 5, a gaseous phase infusion assembly 10 configured to infuse laundry wastewater passing from the inlet to the outlet with the gaseous phase thereby producing a foam phase in container 1 , and an outlet for the foam phase 9, different from the outlet for laundry wastewater 5. In this embodiment an additional mixing device, such as a stirrer 14, is provided in container 1. While many shapes and configurations of the stirrer are within the scope of the present invention, stirrer 14 exemplified in Figure 1 includes a shaft 14a and a stirring member 14b. Figures 4A-C, 5A-B, 6A-B, and 7A-B show different stirring members suitable for use in the present invention.

In compartment 15 the bubbling of the laundry wastewater takes place. In an example of a cylindrical compartment, the diameter of compartment 15 is about 5-15 cm and a height of about 5 -15 cm. The size of compartment 15 will depend on the water flow-rate and the required residence time of microfiber-rich water in compartment 15 for reaching the desired efficiency of separation. The shape of the compartment can vary depending on the application and the configuration of other elements of the apparatus. For example, the compartment 15 may have a generally rectangular tube shape, which can be advantageously used with a porous element 2 shaped as a plate.

At a bottom part of container 1 a porous element 2 having a specific pore size, for example with an average diameter of at least 0.2 pm, or at least 0.1 pm, is positioned. In other examples, the average diameter of the pores is at least 1 pm. In some embodiments, the pores decrease in size from the inlet to the outlet. In particular, porous element 2 can be characterized by a gradient in pore size, starting from larger size pores closer to the inlet (e.g., an average pore size having a diameter of 1 pm) to capture microfibers and then go down in size towards the outlet (e.g., to an average pore size having a diameter of 0.2 pm or as low as 0.1 pm) to capture nanofibers and nanoplastics. In some embodiments, the average diameter of the pores is no more than 1 mm.

Gaseous phase inlet 7 can be connected to a suitable source of gaseous phase, such as an air or carbon monoxide supply. Inlet 7 can be connected to a compressor of a neighbouring household drier (not shown). In such embodiments, at least one valve (not shown) may be provided in or at inlet 7, between the source of the compressed gaseous phase and the interior of the container 1.

Gaseous phase entering container 1 of Figure 1 via inlet 7 passes through a porous element 2. Bubbles are formed at the interface of porous element 2 and laundry wastewater 3, thereby infusing the laundry wastewater 3 with the gaseous phase. An optional additional stirrer 14 agitates laundry wastewater 3 with the bubbles of the gaseous phase, further facilitating the infusion and the formation of a foam phase. In other exemplary embodiments, one or both of porous element 2 and stirrer 14 may be absent and the bubble formation occurs at inlet 7.

In lower part 15 of container 1 bubbly water with microfibers and nanofibers is formed. In upper part 11 of container 1 a wet foam rich in microfibers and nanofibers is formed, where the microfibers and nanofibers would preferably constitute at least 10 wt.% of the entire weight of the wet foam. Foam is generated from bubbling laundry wastewater 3 that contains residual detergent and microfibers. Container 1 is configured such that the foam exits container 1 through a foam outlet 9, which is different from the laundry wastewater outlet 5. Foam from outlet 9 is sent to a second compartment (not shown), where the foam comprising microfibers and nanofibers is isolated and allowed to drain and/or dry. Once dried, the microfibers and nanofibers can be isolated and disposed of as regular household waste.

Figure 2 illustrates another apparatus for the removal of microfibers and nanofibers from laundry wastewater. The main difference between the apparatus according to Figure 1 and Figure 2 is the position of the inlet of the gaseous phase into container 1. Container 1 has an inlet for laundry wastewater 3, an outlet for laundry wastewater 5, a gaseous phase infusion assembly 10 configured to infuse laundry wastewater passing from the inlet to the outlet with the gaseous phase thereby producing a foam phase in container 1 , and an outlet for the foam phase 9, different from the outlet for the laundry wastewater 5. In this embodiment compressed air (or another gaseous phase) flow 7 enters container 1 via stirrer 14 and optionally a porous element 13. In such an embodiment, stirrer 14 has a passage extending therethrough, for example through a shaft 14a, to provide a fluidic communication between gaseous phase inlet 7 and laundry wastewater 3 in the interior of container 1 , via porous element 13, if present. In the latter case, the gaseous phase entering container 1 via inlet 7 passes through the passage in stirrer 14 and porous element 13. Porous element 13 can be assembled with the stirring member 14b of stirrer 14 to provide a fluidic communication between gaseous phase inlet 7 and laundry wastewater 3 in the interior of the container. Bubbles are formed at the interface of porous element 13 and laundry wastewater 3 thereby infusing laundry wastewater 3 with the gaseous phase. If the porous element is omitted, bubbles are formed at the end of the passage in the stirrer 14. The movement of the stirrer 14 further agitates laundry wastewater 3 with the bubbles of the gaseous phase further facilitating the infusion and the formation of foam.

In compartment 15 the bubbling of the laundry wastewater takes place. In an example of a cylindrical compartment, the diameter of compartment 15 is about 5-15 cm and a height of about 5 -15 cm. The size of compartment 15 will depend on the water flow-rate and the required residence time of microfiber-rich water in compartment 15 for reaching the desired efficiency of separation.

Gaseous phase inlet 7 can be connected to a suitable source of gaseous phase, such as an air or carbon monoxide supply. Inlet 7 can be connected to a compressor of a neighbouring household drier (not shown). In lower part 15 of container 1 bubbly water with microfibers and nanofibers is formed. In upper part 11 of container 1 a wet foam rich in microfibers and nanofibers is formed. Foam is generated from bubbling laundry wastewater 3 that contains residual detergent and microfibers and separated from the laundry wastewater, for example, via a separate foam outlet 9. Foam from outlet 9 is sent to a second compartment (not shown) were the foam comprising microfibers and nanofibers is isolated and allowed to drain and/or dry. Once dried, the microfibers and nanofibers can be isolated and disposed as regular household waste.

Figure 3 illustrates another apparatus for the removal of microfibers and nanofibers from laundry wastewater. Container 1 has an inlet for laundry wastewater 23, an outlet for laundry wastewater 25, a gaseous phase infusion assembly 20 configured to infuse laundry wastewater passing from the inlet to the outlet with the gaseous phase thereby producing a foam phase in container 1 , and an outlet for the foam phase 29, different from the outlet for laundry wastewater 25. In this embodiment no stirrer is present in container 1. In lower part 33 of container 1 the flotation takes place. The size of lower part 33 of container 1 will depend on the water flow-rate and the required residence time of microfiber-rich water in lower part 33 of container 1 for reaching the desired efficiency of separation. At the bottom part of lower part 33 of container 1 a porous element 35 having a specific pore size, for example 1 pm average pore diameter, is positioned.

Gaseous phase inlet 27 can be connected to a suitable source of gaseous phase, such as an air or carbon monoxide supply. Inlet 27 can be connected to a compressor of a neighbouring household drier (not shown), for example, via a valve. In lower part 33 of container 1 bubbly water with microfibers and nanofibers is formed. In upper part 31 of container 1 a wet foam rich in microfibers and nanofibers is formed. Foam is generated from bubbling laundry wastewater 23 that contains residual detergent and microfibers and separated from the laundry wastewater, for example, via a separate foam outlet 29. Foam from outlet 29 is positioned at the top of container 1 and sent to a second compartment (not shown) were the foam comprising microfibers and nanofibers is isolated and allowed to drain and/or dry. Once dried, the microfibers and nanofibers can be isolated and disposed of as regular household waste.

FIG. 4A-4C illustrate front views of different embodiments of the apparatus of the present invention. Fig 4A shows an embodiment of an apparatus of the present invention in which the gaseous phase inlet 7 is connected at a lower part 15 of a container. Fig 4B shows an embodiment of the of the apparatus of the present invention in which embodiment compressed air (or another gaseous phase) flow 7 enters container 1 via a top portion of the container, particularly a stirrer 14. In such an embodiment, stirrer 14 has a passage extending therethrough, for example through a shaft 14a, to provide a fluidic communication between gaseous phase inlet and laundry wastewater in lower part 15. Fig 4C shows an embodiment of the of the apparatus of the present invention in which embodiment compressed air (or another gaseous phase) flow 7 enters container 1 via stirrer 14 and a porous element 13. In such an embodiment, stirrer 14 has a passage extending therethrough, for example through a shaft 14a, to provide a fluidic communication between gaseous phase inlet 7 and laundry wastewater in the interior of a container, via porous element 13. In the latter case, the gaseous phase entering the container via inlet 7 passes through the passage in stirrer 14 and porous element 13. Porous element 13 can be assembled with the stirring member 14b of stirrer 14 to provide a fluidic communication between gaseous phase inlet 7 and laundry wastewater in the interior of the container.

Figure 5A shows a top view of exemplary stirring members suitable for use in the present invention. Stirrer 14 has a rotatable shaft 14a and a stirring member 14b. The exemplified stirring member 14b has one or more, and, preferably, a plurality of radially extending sections 14c. The radially extending sections 14c include projections and/or openings in a body portion of the stirring member 14b.

Figure 5B shows a plan view of exemplary stirring members suitable for use in the present invention. Stirrer 14 has a rotatable shaft 14a and a stirring member 14b. The exemplified stirring member 14b has one or more, and, preferably, a plurality of radially extending sections 14c. The radially extending sections 14c include projections and/or openings in a body portion of the stirring member 14b.

Figure 6A shows a top view of exemplary stirring members suitable for use in the present invention. Stirrer 14 has a rotatable shaft 14a and a stirring member 14b. The exemplified stirring member 14b has one or more, and, preferably, a plurality of radially extending sections 14c. The radially extending sections 14c include projections and/or openings in a body portion of the stirring member 14b.

Figure 6B shows a plan view of exemplary stirring members suitable for use in the present invention. Stirrer 14 has a rotatable shaft 14a and a stirring member 14b. The exemplified stirring member 14b has one or more, and, preferably, a plurality of radially extending sections 14c. The radially extending sections 14c include projections and/or openings in a body portion of the stirring member 14b.

Figure 7A shows a top view of exemplary stirring members suitable for use in the present invention. Stirrer 14 has a rotatable shaft 14a, a stirring member 14b and one or more porous elements 14d. The exemplified stirring member 14b has one or more, and, preferably, a plurality of radially extending sections 14c.

Figure 7B shows a plan view of exemplary stirring members suitable for use in the present invention. Stirrer 14 has a rotatable shaft 14a, a stirring member 14b and one or more porous elements 14d. The exemplified stirring member 14b has one or more, and, preferably, a plurality of radially extending sections 14c. The radially extending sections14c include projections and/or openings in a body portion of the stirring member 14b. In some exemplary embodiments, porous elements 14d are positioned between the plurality of radially extending sections 14c. In other exemplary embodiments one or more porous elements 14d is superimposed on the radially extending sections 14c, such as projections and/or openings, of the stirring member 14b.

The apparatus shown in Figures 1-3 will be implemented into commercial laundry machines in line, i.e. by connecting it to the wastewater tubing of the appliance, similar to the current practice of connecting filtering-based devices. A possibility is to implement the apparatus shown in Figures 1-3 as a stand-alone separation device. In another embodiment the apparatus shown in Figures 1-3 may be implemented in series with one or more filters and/or a commercial filtering device for capturing fibers below a lower limit of 30 pm. A synergy in microfiber removal and high efficiency in the whole microfiber size range can be attained which is a first step towards mitigating microplastics.

The present apparatus for the removal of microfibers and nanofibers from laundry wastewater aligns with anticipated Ell legislation and existing mandates for microfiber filters in laundry machines by 2025 (France). Recognizing the difficulty in achieving the required high removal efficiency with current technologies as discussed above, the system according to the present invention emerges as an advanced solution meeting evolving regulatory demands. The system according to the present invention can also be seen as supplementary to existing filtration techniques that cannot capture particles of smaller size.

It is clear that several embodiments as discussed can be combined and that the technical elements and features thus combined can be used in the present method for the removal of microfibers and nanofibers from laundry wastewater.

Claims

1. A method for the removal of microfibers and nanofibers from laundry wastewater, the method comprising the following steps: providing a flow of laundry wastewater comprising microfibers and nanofibers, formation of a foam phase rich in microfibers and nanofibers, separating of the foam phase rich in microfibers and nanofibers from a flow of laundry wastewater depleted of microfibers and nanofibers.

2. A method according to claim 1 , wherein the formation of the foam phase comprises infusing the flow of laundry wastewater comprising microfibers and nanofibers with a gaseous phase thereby creating bubbles in the laundry wastewater.

3. A method according to claim 2, wherein the infusion takes place via a continuous flow of compressed air or carbon monoxide.

4. A method according to claim 1 , wherein the formation of the foam phase comprises agitating the laundry wastewater comprising microfibers and nanofibers mechanically thereby creating bubbles in the laundry wastewater.

5. A method according to claim 2, wherein infusing the flow of laundry wastewater comprising microfibers and nanofibers further comprises passing the gaseous phase through a porous element before the gaseous phase enters the flow of laundry wastewater.

6. A method according to any one or more of the preceding claims, wherein the formation of the foam phase comprises a combination of one or more of infusing the laundry wastewater with the gaseous phase and agitating the laundry wastewater.

7. A method according to any one or more of the preceding claims, wherein the foam phase rich in microfibers and nanofibers is further separated into at least a stream comprising laundry wastewater and a stream comprising microfibers and nanofibers.

8. A method according to claim 7, wherein the stream comprising microfibers and nanofibers is further treated for isolating the microfibers and nanofibers from the stream comprising microfibers and nanofibers, the step of further treating comprises a drying step.

9. A method for washing clothes in a washing machine, wherein clothes are brought into contact with water and detergents and a flow of laundry wastewater comprising microfibers and nanofibers is formed, the method further comprising a method for the removal of microfibers and nanofibers from the laundry wastewater according to any one or more of the preceding claims.

10. An apparatus for the removal of microfibers and nanofibers from laundry wastewater comprising: a container having an inlet for laundry wastewater, an outlet for laundry wastewater, a gaseous phase infusion assembly configured to infuse laundry wastewater passing from the inlet to the outlet with the gaseous phase thereby producing a foam phase, and an outlet for the foam phase.

11. An apparatus according to claim 10, wherein the gaseous phase infusion assembly comprises a gaseous phase inlet for a gaseous phase inflow.

12. An apparatus according to claim 11 , wherein the gaseous phase infusion assembly further comprises a porous element in communication with the gaseous phase inlet.

13. An apparatus according to claim 12, wherein an average diameter of the pores is at least 0.1 pm, preferably at least 0.2 pm.

14. An apparatus according to any one or more of claims 10-13, wherein the infusion assembly comprises a mixing device, such as at least one stirrer.

15. An apparatus according to any one or more of claims 10-13, wherein the infusion assembly comprises a mixing device comprising at least one of a porous member and a stirring member.

16. An apparatus according to claim 14 or 15, wherein the mixing device is disposed at a gaseous phase inlet for a gaseous phase inflow.

17. An apparatus according to any one or more of claims 10-16, wherein the infusion assembly comprises a combination of one or more of an inlet for a gaseous phase inflow, a mixing device, and a porous element.

18. An apparatus according to any one or more of claims 10-17, wherein gaseous phase infusion assembly is disposed at a top portion or at a bottom portion of the container, while the outlet for the foam phase is disposed at a top portion of the container.

19. An apparatus according to any one or more of claims 10-18, further comprising a foam collection compartment in fluid communication with the outlet for the foam phase.

20. An apparatus according to claim 19, further comprising a foam drying assembly in fluid communication with the foam collection compartment.

21. A laundry machine provided with an apparatus according to any one or more of claims 10-20.