NL2027905B1

NL2027905B1 - A method for producing tailored quality water.

Info

Publication number: NL2027905B1
Application number: NL2027905A
Authority: NL
Inventors: Gijsbertus Joseph Van Der Meer Walterus; Antonius Boere Jozef; Peter Wessels Leo; Robin Cornelissen Emile
Original assignee: Allied Waters B V
Priority date: 2021-04-01
Filing date: 2021-04-01
Publication date: 2022-10-17

Abstract

The present invention relates to a method for producing tailored quality water, as well as to an apparatus for producing tailored quality water. The method for producing tailored quality water comprises: i) a step of measuring the concentration of oxygen in the feed water, ii) a step of comparing the concentration of i) with a reference value, iii) a step of lowering the concentration of oxygen in the feed water when the concentration of i) is higher than the reference value, iv) repeating the step of lowering the concentration of oxygen in the feed water until the concentration of oxygen in the feed water is equal to or lower than the reference value.

Description

Title: A method for producing tailored quality water. Description The present invention relates to a method for producing tailored quality water, as well as to an apparatus for producing tailored quality water.

The presence of emerging pollutants in aquatic environment poses great challenges for drinking water treatment plants. In the last decades, water supply companies are confronted with an increasing amount of new emerging pollutants or contaminants of emerging concern. This fact, combined with an ongoing improvement of laboratory equipment that are able to detect more compounds at increasingly lower detection limits, and a highly sensitive intuitive public repulsion against the idea of pharmaceuticals in drinking water, led to an ongoing improvement of existing water purification technologies. The challenges of the water sector in a changing world underline the need for updating the existing water purification technologies to use water resources sustainably in the future.

Emerging pollutants e.g. pharmaceuticals, personal care productions, UV filters, endocrine disruptors, illicit drugs, additives, metabolites, disinfection by-products, fire retardants and pesticides, are surplus results of chemical and/or biological substances generated mainly by human activities. Once released into the aquatic environment (e.g. groundwater and surface water), these emerging pollutants are subject to chemical photochemical and biodegradation which change their environmental behaviour and ecotoxicological profile. The bioaccumulation, bio magnification, persistency and toxicity of emerging pollutants are harmful for both aquatic organisms and humans, causing endocrine disturbing effects, estrogenic or hormone disruption, foetal malformation, or even DNA damages [5].

To ensure drinking water safety, worldwide legal water quality standards have been established for a limited number of anthropogenic compounds. For instance, the US Environmental Protection Agency (EPA) has recently established a health advisory levels at 70 parts per trillion (70 ng/L = 0.07 mg/L) for PFOA and PFOS in drinking water, which is incredibly low compared to the generally accepted threshold of the toxicological concern (TTC), where values below 0.1 mg/L were found to be insignificant. In the Netherlands, where non-chlorinated drinking water is distributed, the prevention of regrowth of bacteria in the distribution network is an extra topic of concern.

Research implicates strongly that less particles and less nutrients in the drinking water leads to less risks of the growth of opportunistic pathogens.

The high standards for drinking water production and distribution result in adding extra purification steps to the existing treatment plant.

The emerging pollutants in the water source due to the industrial development potentially affect human health, while the removal of trace concentrations of the emerging individual compounds or chemical mixtures using conventional drinking water treatment series are not fully achieved.

Advanced oxidation processes including UV/H20O2, O3/H20O2 UV/Os-based applications, Fenton processes, and photocatalytic oxidative processes seem to be effective in removing natural organic matter and mitigating disinfection by-products.

However, advanced oxidation only breaks down the natural organic matter into small aliphatic and hydrophilic compounds, among other compounds, without complete oxidation.

The low-molecule hydrophilic compounds could be either degradable or persistent and toxic, and the development of unwanted by-products pose challenges to large-scale application.

In addition, granular or powdered activated carbon adsorption is also used for removing emerging pollutants in drinking water facilities, while the energy consumption and adsorbents cost are very high.

Moreover, the impact of each stage of the drinking water treatment plant (e.g. construction, operation, chemical use, treatment processes) on the climate change (i.e. energy consumption and greenhouse gas emission) plea for improvements for more sustainable techniques for water supply.

A drinking water purification process comprises a step of the uptake of water from surface waters or groundwater and storage.

Aeration of groundwater and natural treatment of surface water are in some processes standard activities.

Often softening and pH-adjustments already takes place during these processes.

Pre-filtration may comprise so called rapid sand filtration or in some cases microfiltration in drum filters.

In some situations the addition of chemicals may be necessary, for example pH adjustment through addition of calcium hydroxide and sodium hydroxide.

In some cases there is FeCl; addition to induce flocculation for the removal of humic acids and suspended particulate matter, if necessary with the addition of an extra flocculation aid.

Flocs are then formed and may be removed through settling in lamellae separators or flotation.

After that the flocs are concentrated in sludge and pumped to the exterior for safe removal of the particulates and sludge dewatering.

In the Netherlands infiltration of the pre-treated surface water may take place in sand dunes for natural purification. In some cases a step of disinfection by chlorination, ozonation or UV disinfection is used. Ozone not only inactivates or kills bacteria and viruses; it may also improve taste and odour properties and breaks down micro pollutants. An additional step is fine filtration, i.e. slow sand (media) filtration for the removal of the residual turbidity and harmful bacteria. Activated carbon filtration is used for further removal of matter affecting taste and odour and remaining micro pollutants. The drinking water thus obtained will eventually be distributed to users through pipelines and distribution pumps. Untreated or raw water may be stored in reservoirs, such as the Biesbosch (NL), where it undergoes natural treatment.

Japanese patent publication No. 58 011091 relates to a method for de-aerating water, wherein first a flocculation agent and an auxiliary substance are injected into the liquid to be treated, which contains oxygen. Then the flow of water thus pre-treated is passed through a sand filter, after which the obtained filtrate is continuously passed through a de-aeration unit. The water thus obtained, from which the oxygen has been removed, is mixed with a reduction agent, for example a sulphite compound, and subsequently supplied to a membrane unit.

Japanese patent No. 06 126299 relates to a water treatment plant which is successively provided with an active carbon filter, a de-aeration element, as well as a membrane filtration unit of the reverse osmosis type, whereby the water to be treated, which contains dissolved oxygen, is continuously passed through the de- aeration element.

Fouling of the membrane surface may be of a reversible or of an irreversible nature. In the case of reversible fouling, the membrane surface can be cleaned by rinsing it with a special solution, for example a soap, acid or lye solution. From practice it is known, however, that frequent, that is, monthly cleaning may reduce the life of the membranes considerably, so that the cost of the plant may increase considerably. In the case of irreversible fouling, it is not possible to clean the membrane surface with the above-mentioned agents. Fouling cannot be removed at all and, depending on the rate of contamination, this may result in a very short life time of the membranes, which is generally accompanied with a decrease in the productivity. Thus, the cost of the plant will increase considerably. A way of preventing or strongly reducing fouling which is frequently used in practice is to subject the water to be purified to a pre-treatment scheme. In the embodiment wherein ground water is purified, such a pre-treatment generally consists of an aeration step and one or more filtration steps. In the embodiment wherein surface water is purified, such a pre-treatment consists of a coagulation step, a flocculation step and a filtration step. In both filtration steps, which are carried out under aerobic conditions, suspended substances and iron and manganese flocks, which flocks are considered as iron and manganese hydroxides, are removed to a considerable degree from the starting material to be treated. Although the iron content and the manganese content can thus be reduced to < 0.02 and < 0.0005 mg/l respectively, the membranes must still be cleaned two to four times a year on average in order to maintain a reasonable water production per membrane element.

One drawback of such a pre-treatment is the fact that additional plants must be built, so that the total cost will increase. Besides, such plants require the possible addition of further chemicals, which chemicals may have an adverse effect on the quality of the eventual drinking water. Moreover, malfunctions do occur with such plants, which malfunctions may disturb the production of the eventual drinking water.

The water production facilities are usually equipped with pre- treatment steps for conditioning and modifying the feed water to prevent clogging and fouling of the membrane modules. Biofouling is problematic biofilm formation and is caused by bacteria in combination with nutrients and oxygen in feed water which need extra attention and maintenance. Moreover, the feed water containing both Fe? and O: will always lead to the precipitation of Fe(OH)s, especially when feed water containing Fe?" is contacted with air, for example during aeration of the feed water. This precipitation can seriously hinder the performance of reverse osmosis membranes, which need an extra pre-treatment step of the feed water e.g. trickling filter before the membrane filtration unit.

An object of the present invention is to provide a method for producing high tailored quality water, wherein feed water is purified via a purification system based on membranes chosen from the group of reverse osmosis and nanofiltration.

Another object of the present invention is to provide a method for producing tailored quality water, wherein several types of feed water can be directly supplied to a purification system based on membranes chosen from the group of reverse osmosis and nanofiltration.

5 Another object of the present invention is to provide a method for producing tailored quality water, wherein the feed water to be purified is pre-treated in such a way that the formation of biofilms on the surface of the membranes is reduced or minimized.

The present invention thus relates to a method for producing tailored quality water, wherein feed water is purified via a purification system based on membranes chosen from the group of reverse osmosis and nanofiltration, or a combination thereof, to supply tailored quality water, wherein the concentration of oxygen in the feed water is less than 0.10 mg O?/I feed water.

The present inventors found that the concentration of oxygen in the feed water is a critical parameter for operating the membranes chosen from the group of reverse osmosis and nanofiltration, especially the reverse osmosis membranes. For a continuous production of tailored quality water without clogging and fouling of the membrane modules the concentration of oxygen in the feed water needs to be less than 0.10 mg O:/ feed water. If the concentration of oxygen in the feed water is higher than 0.10 mg O:/ feed water, biofouling from nutrients and oxygen may occur in a short period of operating time. Biofouling is caused by bacterial growth as a result of enough nutrients and oxygen in the case of aerobic biofilm growth. Aerobic biofilm growth is known to be significantly faster than anaerobic biofilm growth.

The term “feed water” means the flow of water that is to be fed to the purification system.

The term “tailored quality water’ comprises water to be used for a specific purpose. For example, the requirements for producing drinking water are different for producing, for example, industrial process water, such as boiler feed water. Examples of tailored quality water include drinking water, water for the food and beverage industry, industrial process water (e.g. boiler feed water, ultra-pure water), water for horticulture and other agricultural applications and infiltration for aquifer recharge, but are not limited thereto. In an example tailored quality water is drinking water.

The present method can be carried out on a continuous basis and on a discontinuous basis. In this context “a continuous basis” means that during the whole process of producing tailored quality water the concentration of oxygen in the feed water is less than 0.10 mg O>/I feed water.

In this context “a discontinuous basis” means that only during a certain time period of the process of producing tailored quality water the concentration of oxygen in the feed water is less than 0.10 mg Ol feed water. For example, in a 24 hours operation, the purification system is operated during a period of at least 30 minutes, preferably at least 45 minutes, more preferably 60 minutes with a feed water having a concentration of oxygen in the feed water of less than

0.10 mg O/I feed water. This means that during the other hours of 24 hours operation the purification system is operated with a feed water having a concentration of oxygen in the feed water of more than 0.10 mg O,/l feed water. The present inventors assume that even a short period of run time with a feed water having a concentration of oxygen in the feed water of less than 0.10 mg O>/I feed water is effective in preventing the formation of biofilms on the membrane surfaces.

In an example of the present method for producing tailored quality water the concentration of oxygen in the feed water is less than 0.05 mg O./I feed water, preferably less than 0.02 mg O./I feed water. The present inventors found that such a low concentration of oxygen in the feed water provides a maintenance free operation of the membrane modules with regard to the formation of biofilm on the surface of the membrane modules.

In an example of the present method for producing tailored quality water the method further comprises: i) a step of measuring the concentration of oxygen in the feed water, ii) a step of comparing the concentration of i) with a reference value, iii) a step of lowering the concentration of oxygen in the feed water when the concentration of i) is higher than the reference value, iv) repeating the step of lowering the concentration of oxygen in the feed water until the concentration of oxygen in the feed water is equal to or lower than the reference value.

The present inventors found that in some sources of feed water the concentration of oxygen is higher than a reference value, e.g. 0.10 mg O./l feed water. In such a case it is necessary to lower the concentration of oxygen in the fed water before supplying the feed water to the membrane modules. For a continuous production of tailored quality water the concentration of oxygen in the feed water is measured and the measured value is compared with the reference value. If the measured concentration of oxygen in the feed water is too high, i.e. above the reference value, the concentration of oxygen in the feed water needs to be lowered. Such a lowering of the concentration of oxygen in the feed water can be carried out in different ways, or a combination of different measurements, as will be discussed now. For example, the feed water can flow through a soil passage to the collection wells before abstracted as water source. Such a passage may also lead to a removal of particles. In another example the feed water is subjected to biological activated carbon (BAC) filtration or (rapid) sand filtration. In some cases BAC treatment or (rapid) sand filtration of surface water may need the addition of nutrients. In another example the feed water is subjected to vacuum degassing or N2 stripping. Another example of lowering of the concentration of oxygen in the feed water is the dosage of oxygen scavengers to the feed water. Examples of oxygen scavengers are sodium bisulphite and hydrazine. Sodium Bisulfite (SBS) can be used as a non-oxidizing inhibitor of biological growth at higher doses, particularly for aerobic bacteria. SBS at higher doses may be considered to have biostatic properties that inhibit biological growth, in part by removing available oxygen to aerobic bacteria, which in turns creates a hostile environment for bacteria, algae, and fungi to grow. To control biological growth with sodium bisulfite, it is preferably applied at a dosing rate of at least 100 ppm, preferably at least 300, more preferably 500 ppm for 30 to 60 minutes daily.

The step of lowering of the concentration of oxygen in the feed water is continued until the concentration of oxygen in the feed water is equal to or lower than the reference value. The afore mentioned steps i) —iv) are carried out with measurement and control systems based on computers.

In an example of the present method for producing tailored quality water the reference value is 0.10 mg O?/l feed water, preferably less than 0.05 mg Ol feed water, more preferably less than 0.02 mg O:/I feed water.

In an example of the present method for producing tailored quality water the feed water is chosen from the group of salt water, brackish water, groundwater, surface water, seawater, sewage treatment plant effluent, storm water, rainwater, and process water, or a combination thereof.

In an example of the present method for producing tailored quality water the purification system further comprises one or more pre-treatment units chosen from the group of dry sand filtration, softening, rapid sand filtration, activated carbon filtration and UV disinfection, wherein the pre-treatment units are located upstream with respect to the membranes chosen from the group of reverse osmosis and nanofiltration, or a combination thereof. It is to be noted that the pre-treatment units are operated in such way that favourable conditions for the formation of biofilms on the surface of the membranes are minimized.

In an example of the present method for producing tailored quality water the purification system further comprises one or more post-treatment units chosen from the group of ion exchange, dosing of CO, dosing of lime, calcite filtration, degasification and aeration, wherein post-treatment units are located downstream with respect to the membranes chosen from the group of reverse osmosis and nanofiltration, or a combination thereof.

The present invention also relates to an apparatus for producing tailored quality water, the apparatus comprises: a) an inlet for feed water into a purification system, b) a purification system comprising membranes chosen from the group of reverse osmosis and nanofiltration, or a combination thereof, and c) an outlet for tailored quality water from the purification system. In an example the apparatus also comprises a cleaning system for cleaning the membranes.

In an example the present apparatus for producing tailored quality water further comprises means for measuring the concentration of oxygen in the feed water before the feed water is supplied to the purification system, means for comparing the measured concentration of oxygen in the feed water with a reference value, and means for lowering the concentration of oxygen in the feed water before the feed water is supplied to the purification system when the measured concentration of oxygen in the feed water is higher than the reference value.

The commonly used methods of dissolved oxygen detection include iodometric titration, electrochemical detection, and optical detection. Electrochemical detection is a common measurement method of dissolved oxygen. Electrochemical dissolved oxygen sensors can realize in situ online measurements. Detection mechanisms and materials of electrochemical and optical detection methods are reviewed in an article written by Yaoguang Wei, Yisha Jiao, Dong An, Daoliang Li ‚Wenshu Li and Qiong Wei, “Review of Dissolved Oxygen Detection Technology:

From Laboratory Analysis to Online Intelligent Detection”, Sensors 2019, 19, 3995; doi:10.3390/s19183995 http://www.mdpi.com/journal/sensors. The content of that document, i.e. the dissolved oxygen sensors, is hereby incorporated by reference. In an example the means for lowering the concentration of oxygen in the feed water comprise means for subjecting the feed water to soil infiltration. Another example of the means for lowering the concentration of oxygen in the feed water comprise subjecting the feed water to biological activated carbon (BAC) filtration. Another example of the means for lowering the concentration of oxygen in the feed water comprise subjecting the feed water to sand filtration, vacuum degassing or Ns stripping. Another example of the means for lowering the concentration of oxygen in the feed water comprise the dosage of oxygen scavengers, such as sodium bisulphite, to the feed water. In an embodiment of the present apparatus it is also possible to combine one or more of the aforementioned means for lowering the concentration of oxygen in the feed water.

The present apparatus for producing tailored quality water can be used for closing the water loop. Surface water and groundwater are purified for municipal, agricultural, industrial use, which finally end up as wastewater. The collected wastewater is further treated to meet the requirement to be discharged into the surface water or recharged into the underground aquifer, which could be reuse for producing tailored quality water. Moreover, rainwater, storm and high flow flood streams can also be reserved in the groundwater base flow to augment domestic and industrial supply via managed aquifer recharge. This finally leads to a closed water loop that recycling the water source to meet the increasing water demand as well as reduce the volume of waste water.

The present invention relates to the use of the apparatus as discussed above for producing tailored quality water, too.

In an example the purification system comprises reverse osmosis membranes only. In an example the purification system comprises nanofiltration membranes only.

In an example the purification system comprises reverse osmosis membranes and nanofiltration membranes.

The present invention will be explained in more detail hereunder based on an example, wherein it must be clear that the example is not to be seen as a limitation of the scope of protection but merely as an explanation of the present invention.

Figure 1 shows a flow diagram of the present for producing tailored quality water.

A water source 2, chosen from the group of salt water, brackish water, groundwater, surface water, seawater, sewage treatment plant effluent, storm water, rainwater, and process water, or a combination thereof, especially surface water, is used for the production of tailored quality water 7. The raw water 1 of the water source 2 is fed as stream 3 to a purification system 6 based on membranes chosen from the group of reverse osmosis and nanofiltration, or a combination thereof. Before stream 3 is supplied to the purification system 6 the concentration of oxygen is measured in unit 9. If the concentration of oxygen is higher than a reference value, e.g. 0.10 mg O2/I , then it is necessary to lower the concentration of oxygen before supplying stream 3 to the purification system 6. Measuring of the concentration of oxygen can take place continuously or intermittently.

In a process for the production of tailored quality water the concentration of oxygen is measured and the measured value is compared with the reference value. If the measured concentration of oxygen is too high, i.e. above the reference value, the concentration of oxygen needs to be lowered. Such a lowering of the concentration of oxygen can be carried out in different ways as mentioned above.

In the present example the concentration of oxygen is lowered via a dosage unit 11, i.e. the dosage of sodium bisulphite. The step of lowering of the concentration of oxygen is continued until the concentration of oxygen is equal to or lower than the reference value. The permeate flow of the membrane modules (not shown) purification system 6 is high quality water 7, i.e. tailored quality water. For legibility reasons, pumps, valves, pre-treatment units and post treatment units have been omitted.

In case the concentration of oxygen in stream 8, measured in unit 9, is too high, a signal 10 is sent to dosage unit 11. In this example dosage unit 11 provides a dosage of sodium bisulphite 12 to the stream 3, resulting in a stream 4 having a lowered concentration of oxygen. The concentration of oxygen in stream 4 is measured again via stream 8. Stream 5 having a lowered concentration of oxygen is supplied to purification system 6.

In case the concentration of oxygen in stream 8, measured in unit 9, is below a reference value, there will be no signal 10 sent to dosage unit 11. Thus, there will be no dosage of sodium bisulphite 12 to stream 3. Stream 3 is supplied to purification system 6. In an example the concentration of oxygen in the feed stream supplied to the purification system is continuously maintained on a level lower than

0.10 mg Oy/I feed water. In another example, the concentration of oxygen in the feed stream supplied to the purification system is only during a certain time period maintained on a level lower than 0.10 mg O./I feed water. This means that during the other period of operation the purification system is operated with a feed water having a concentration of oxygen of more than 0.10 mg Oz feed water. The present inventors assume that even a short period of run time with a feed water having a concentration of oxygen in the feed water of less than 0.10 mg O?>/l feed water is effective in preventing the formation of biofilms on the membrane surfaces.

Claims

CONCLUSIONS

A process for preparing tailor-made quality water, wherein feed water is purified via a purification system, based on membranes, selected from the group of reverse osmosis and nanofiltration, or a combination thereof, to provide tailor-made quality water, wherein the concentration of oxygen in the feed water is less than 0.10 mg O:/l feed water.

A method for preparing tailor-made quality water according to claim 1, wherein the concentration of oxygen in the feed water is less than 0.05 mg of feed water, preferably less than 0.02 mg of O 2 feed water.

A method for preparing tailor-made quality water according to any one of the preceding claims, the method further comprising: i) a step of measuring the concentration of oxygen in the feed water, iy a step of comparing the concentration of i) with a reference value, iii) a step of decreasing the concentration of oxygen in the feed water when the concentration of i) is higher than the reference value, iv) repeating the step of decreasing the concentration of oxygen in the feed water until the concentration of oxygen in the feed water is equal to or lower than the reference value.

Method for preparing tailor-made quality water according to claim 3, wherein the reference value is less than 0.10 mg O:/l feed water, preferably less than 0.05 mg O 2 feed water, in particular preferably less than 0.0. 02 mg O:>l feed water.

The method of preparing quality tailor-made water according to any one of claims 3-4, wherein the step of decreasing the concentration of oxygen in the feedwater comprises treating the feedwater with one or more of the group consisting of from soil infiltration,

biologically activated carbon (BAC) filtration, sand filtration, vacuum degassing, N: stripping and dosing of oxygen scavengers, such as sodium bisulfite.

A method for preparing tailor-made quality water according to any one of the preceding claims, wherein during the entire process of preparing tailor-made quality water the concentration of oxygen in the feed water is less than 0.10 mg O: feed water.

The method of preparing quality tailor-made water according to any one of claims 1-6, wherein the concentration of oxygen in the feedwater is less than 0 only during a certain period of time of the process of preparing quality tailor-made water. 10 mg O?2/I feed water.

Process for preparing tailor-made quality water according to one or more of claims 6-7, wherein the reference value of step ii) is less than 0.10 mg O)/l feed water, preferably less than 0.05 mg O2/I feed water, especially preferably less than 0.02 mg O./L feed water.

A method for preparing tailor-made quality water according to any one of the preceding claims, wherein the feed water is selected from salt water, brackish water, groundwater, surface water, sea water, effluent from a sewage treatment plant, storm water, rain water and process water, or a combination of this.

A method for preparing tailor-made quality water according to any one of the preceding claims, wherein the purification system further comprises one or more pre-treatment units selected from the group of dry sand filtration, softening, rapid sand filtration, activated carbon filtration and UV disinfection, wherein the pre-treatment units are located upstream with respect to the membranes selected from the group of reverse osmosis and nanofiltration, or a combination thereof.

Method for preparing tailor-made quality water according to one or more of the preceding claims, wherein the purification system further comprises one or more after-treatment units selected from the group of ion exchange, dosing of lime, dosing of CO 2 , calcite filtration, degassing and aeration, wherein the after-treatment installations are located downstream with respect to the membranes selected from the group of reverse osmosis and nanofiltration, or a combination thereof.

A method for preparing quality tailor-made water according to one or more of the preceding claims, wherein the tailor-made quality water is selected from the group consisting of drinking water, water for the food and beverage industry, industrial process water such as boiler feed water, high purity water , water for agricultural and horticultural applications and infiltration for aquifer recharge, or a combination of these.

The method of preparing quality tailor-made water according to claim 12, wherein tailor-made quality water is drinking water.

Apparatus for preparing tailor-made quality water, comprising an inlet for feed water in a purification system, the purification system comprises membranes selected from the group consisting of reverse osmosis and nanofiltration, or a combination thereof, and an outlet for tailor-made quality water from the purification system.

Apparatus for preparing tailor-made quality water according to claim 14, further comprising means for measuring the concentration of oxygen in the feedwater before the feedwater is supplied to the purification system, means for comparing the measured concentration of oxygen in the feedwater with a reference value, means for reducing the concentration of oxygen in the feed water before the feed water is supplied to the purification system when the measured concentration of oxygen in the feed water is higher than the reference value.

An apparatus for preparing quality tailor-made water according to claim 15, wherein the means for decreasing the concentration of oxygen in the feedwater comprises treating the feedwater with one or more of the group consisting of soil infiltration, biologically activated carbon ( BAC) filtration, sand filtration, vacuum degassing, N: stripping, dosing of oxygen scavengers, such as sodium bisulfite.

Use of a device according to one or more of the claims 14-16 for the preparation of tailor-made quality water.

Use according to claim 17, wherein the tailor-made quality water is selected from the group consisting of drinking water, water for the food and beverage industry, industrial process water, such as boiler feed water, high purity water,

water for agricultural and horticultural applications and infiltration for aquifer recharge, or a combination of these.

Use according to any one of claims 17-18, wherein custom quality water is drinking water.