NL1017428C2 - Purification process testing method, e.g. for drinking water installations, comprises determining purification performance of several purification method combinations - Google Patents

Abstract

Steps of providing a fluid for purification, purifying the fluid using a combination of fluid purification processes, removing the fluid and determining the purity of the purified fluid are repeated steps for one or more combinations of fluid purification processes, and the purification performance of each of the fluid purification process combinations is determined. A method for testing the purification performance of a number of fluid purification processes comprises the following steps: (a) providing a fluid for purification; (b) purifying the fluid using a combination of fluid purification processes; (c) removing the fluid; (d) determining the purity of the purified fluid; (e) repeating steps (a)-(d) for one or more combinations of fluid purification processes; and (f) determining the purification performance of each of the fluid purification process combinations. Independent claims are included for the following: (1) testing apparatus used to carry out this method; and (2) an arrangement comprising a container (1) which contains the testing apparatus and has connections (2, 3) in its wall for the purification unit fluid inlet and outlet (6, 11).

Description

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APPARATUS, COMPOSITION AND METHOD FOR TESTING THE PURIFYING POWER OF DIFFERENT PURIFICATION UNITS RESPECTIVE PURIFICATION METHODS

Water comes in various purities.

The purity depends on the (pre) treatment that the water has undergone. Groundwater, tap water and rainwater have a different spectrum of pollutants due to the differences in the form of the water and the environmental processes that affect the water. Due to the difference in purity, the water is used in various applications.

Tap water is often used if relatively pure water is needed. In special applications, however, it may also be necessary to further purify tap water.

Many techniques have been developed for purifying a fluid in general and water in particular. Depending on the starting composition and the intended purity, the fluid undergoes a treatment in which impurities are removed. The purification techniques are often overlapping. This means that several types of contamination can often be removed with a technique. For example, a bag filter can be used for floating dirt in water. However, a sand bed filter can also remove a combination of coarse and floating dirt by filtration.

Each technique as indicated above has its specific characteristics with regard to effectiveness, reliability, costs and the like. If a water stream needs to be purified, a number of alternatives are often available in principle. If a purification cannot be achieved with one purification technique, then several techniques must be cascaded.

The search for the correct method of purification (purification techniques) or the correct cascade of purification techniques is usually done on a theoretical basis, for example by having an engineering firm carry out a theoretical design method.

The drawback of this is that in practice it often appears that a certain purification technique or a certain cascade of purification techniques does not realize the desired purity of the fluid to be treated. Components occurring in low concentrations can have a disruptive effect in practice, because their influence has not been recognized during the design phase or has been estimated at least incorrectly.

A further drawback is that in practice it appears that the purity of the treated fluid is amply exceeded. Although the fluid technically meets the quality requirements, there is a non-optimum situation since the chosen cascade has a greater purification capacity than is required. This can lead to too high investment costs, as a result of which a purification project or reuse project (the latter ie a project in which water that has been polluted by use is purified for reuse) does not meet the economic criteria set in the design phase.

From the European patent application EP 0 976 684 A1 a device is known in which a number of groundwater purification units placed one after the other can be tested with the aid of a test installation reconstructed on a very small scale. A drawback of this device, however, is that the order of purification units and therefore the order of the purification techniques carried out one after the other is fixed. The known device is therefore unsuitable for searching for the optimum cascade of purification techniques. A further drawback is that the scale size of the known device is too small (capacity in the order of magnitude of 600 ml / hour) to ensure reliable extrapolation to a full-scale purification plant.

It is an object of the present invention to provide an apparatus, assembly and method for testing the purifying power of purifying units or. to provide purification methods in which at least one of the above-mentioned drawbacks is overcome.

According to a first aspect of the invention, a method is provided for testing the purifying power of combinations of a number of purification methods for purifying a fluid, comprising - supplying a fluid to be purified; - purifying the supplied fluid in a combination of purification methods 15; - discharging the purified fluid; - determining the purity of the purified fluid for the combination of purification methods; - repeating the steps of supplying fluid to be purified, purifying fluid, draining the fluid and determining the purity of the fluid for one or more other combinations of purification methods; and deriving from the purities determined for the various combinations of purification methods the purifying power of each of said combinations of purification methods.

According to a second aspect of the invention, there is provided a device for testing the purifying power of combinations of a number of purification units for purifying a fluid, comprising: - a feed for supplying a fluid to be purified; - purifying means 35 connectable to the supply for purifying the supplied fluid; - drain connected to the purification means for discharging purified fluid; wherein the purifying means comprises: 1017428 4 - two or more purification units for purifying the fluid in two or more purification methods; - guide means for guiding the fluid from the feed through a first combination of purification units connected in series to the outlet and subsequently guiding the fluid from the feed through a second combination of purification units connected in series to the outlet; determining means for determining the purities of the fluid purified by the first combination and the second combination of purification units at one or more positions.

A device is also provided for testing the purifying capacity of combinations of a number of purification units for purifying a fluid, comprising: a supply for supplying a fluid to be purified; - purifying means 20 connectable to the supply for purifying the supplied fluid; - drain connected to the purification means for discharging purified fluid; the purifying means comprising: - a first purification unit for purifying fluid according to a first purification method; - a second purification unit for purifying fluid according to a second purification method; - guide means for guiding the fluid from the supply via a series connection from the first and second purification unit to the output; - determining means for determining the purity of the fluid at one or more positions, the guide means also being adapted to guide the fluid from the supply through the first purification unit to the outlet and / or to guide the fluid from the fluid supply through the second purification unit to the output.

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With the method and device according to the invention described above, a number of predetermined sequences of series-connected purification methods can be tested in practice within a relatively short time. Moreover, different purification units can be run through during testing, whereby the effects on the end result and also the economic return can be determined quickly. As a result, critical details become visible in practice and the final design of a purification plant can be realized with a relatively small uncertainty.

According to a preferred embodiment of the invention, the device has a capacity in the order of magnitude of 1000 liters per hour. Too small a test installation has the disadvantage that the results of the measurements of the purities of the fluid cannot be extrapolated with sufficient reliability to purification plants of actual size. Too large a test installation has other drawbacks, including the high costs thereof and the lack of mobility. In practice it has been found that with a test installation with a capacity of approximately 1000 liters per hour a sufficient scale size is provided, on the basis of which an extrapolation to a purification installation on a full scale can take place.

According to a preferred embodiment, the supply comprises a storage device for storing the fluid. Such a storage device, for example in the form of a supply tank or storage tank, promotes product equalization.

By this is meant that any fluctuations in the composition of the supplied fluid are "damped" in order to be able to carry out the determination of the effect of the different purification methods in a more stable manner.

According to a further preferred embodiment, the device comprises adding means for adding additives to the supplied fluid in order to influence the purification process. For example, acids 1017428 6 or bases for pH corrections or additives for coagulation.

According to a further preferred embodiment, the device comprises a stirring mechanism for keeping the fluid in the storage member in motion, the bottom of the storage member being conical or with a circular bottom so that blind spots are avoided.

According to further preferred embodiments of the invention, the device comprises one or more of the following purification units: - mechanical filtration means for removal of relatively coarse parts from the fluid; bag filter filtration means for removing smaller parts from the fluid; Sand bed filtration means for removing relatively fine parts from the fluid; microfiltration means for removing micro-fine parts from the fluid; aerobic treatment means for degradation of organic substances in the fluid; adsorbents for removal by adsorption of parts of a desired type; ion exchange means for removing ions of a desired type; - disinfectants for removal of microbiological contamination; and / or reverse osmosis means for removing further parts from the fluid.

According to a further preferred embodiment, the test device is reduced in scale, preferably by a factor of two or more, with respect to a water purification plant. The device is so reduced that it can be received in a container, for example a standard sea container, and can therefore be transported easily.

According to a further aspect of the invention, an assembly is provided for testing the purifying power of different purification units comprising: - a container; - a device 5 of the type described above arranged in the container; - connections for supply and disposal provided in the container wall. By using such a (sea) container, the device is easily transportable and the purification units are protected against external influences. The connections are provided in the container wall for connecting a fluid flow to be tested to the supply in a simple manner and connecting the discharge to a possibly provided discharge element outside the container.

According to a further preferred embodiment, the assembly comprises control means for controlling the guide means and purifying means from outside the container. From the outside, that is, without entering the container, the different purification methods can be tested either separately or in cascade.

Further advantages, features and details of the present invention will be elucidated in the following description of a preferred embodiment of the invention, in which reference is made to the accompanying figure.

Figure 1 shows a preferred embodiment of an assembly according to the invention; and Figure 2 shows a schematic diagram of 30 possible purification units according to the invention.

Figure 1 shows a container 1 in which a connection 2 for connecting a supply pipe 6 and a connection 3 for connecting a discharge pipe 11 are provided. Supply tube 6 is connected to purification units 5 and 4 by means of tubes 7 and 8, respectively. Between purification unit 4 and discharge tube 11 a tube 10 is provided and between purification unit 5 and discharge tube 11 a tube 9 is provided. By means of 1017428 8 of a number of (schematically shown) valves 13 and 15, supply flow through supply tube 6 can be purified via either the purification unit 4 or the purification unit 5.

To enable a series connection of purification units 4 and 5, a connecting tube 12 is provided between them. The flow through this tube 12 can be controlled with the aid of valve mechanism 14. This makes it possible to first feed a feed stream via purification unit 4 and then via purification unit 5, so that the effect of two purification methods connected in series can be measured one after the other. It is, of course, also possible to reverse the sequence, that is to say that the supplied stream is first of all passed through purification unit 5 and then through purification unit 4.

Figure 1 shows diagrammatically that a measuring element 16 is provided in the supply pipe 6, a measuring element 17 in discharge pipe 11 and a measuring element 18 in connecting pipe 12. The purity of the water can be measured with the measuring members 16, 17 and 18. For measuring purity, standard measuring equipment known in the art can be used.

The valve mechanisms 13, 14 and 15 can be controlled by an operator by means of control means 19, preferably located outside the container. In some preferred embodiments, the measuring means 16, 17 and 18 can also be read remotely by the control means 19.

It is noted that in another preferred embodiment, not shown, the manner of connecting the purification units in series takes place with the aid of hose connections. With such hose connections, any combination of purification units, that is, any order of the purification units arranged in series, can be achieved.

In another preferred embodiment, not shown, the purity of the water can be determined by analyzing a sample that has been taken manually. The water can hereby be selectively analyzed for those parameters that are relevant in the relevant application.

Figure 2 shows a schematic diagram of a number of different purification methods used in the invention. Purifying member 20 is intended for the separation of coarse particles. In this case, a coarse filter with a filter basket can be used, whereby the mesh size can be varied from approximately 1 mm to approximately 10 mm by using other filter baskets. The second filtration step 21 is a fine filter, in which use is made of filter bags. The mesh size is, for example, between 100 and approximately 1200 microns. The mesh size of the bag filter will be approximately 10% of the mesh size of the coarse filter (ie 5 mm for the coarse filter and, for example, 500 microns for the bag filter). The choice of mesh size in both filters depends on the particle size and the solids content of the water flow offered.

Purification step 22 relates to a continuous self-cleaning sand bed filter, whereby the size of the sand particles, the filtration speed and the design of the washer can be varied. The sand filter has a filtering surface of 0.2 m2. The pore size of a sand filter varies in practice from a few microns to about 50 microns, depending on the medium and the accumulated dirt layer.

Purifier 23 comprises a test skid that can test both micro, ultra and nanofiltration in a single membrane filtration, both a cross flow and a dead end configuration. With a so-called cross-flow configuration, the fluid is transported along the filter surface at a relatively high speed. With a so-called dead-end configuration, the fluid is constantly pressed against the filter surface. The flux, the type of cleaning chemicals and the durability of the membranes are the parameters that can be determined with this skid.

1/10/10

Purifier 24 is a trickle bed column in which organic contamination is oxidized in an aerobic manner with the aid of biomass and by the addition of oxygen (usually in the form of air). The column is filled with polystyrene. Variables that can be tested are flow rate and the biologist's dependence on the input pH. Herein it can be determined what the efficiency of the technology is when using the water flow offered, how often regeneration must take place and how much sludge is formed during regeneration. It can also be determined which and how many nutrients are required for the addition of nitrogen and phosphorus.

The purifier 25 is a technology in which different resins (cationic or anionic) can be used. The system is equipped with a storage tank (not shown) for dosing the regenerant. The test exchanger can also serve as a softener. In this case, a resin is used for calcium removal and is regenerated with a common salt solution.

Purifier 26 relates to a unit filled with active carbon. The unit is intended for adsorption of organic compounds that occur in low concentrations.

Purifier 27 relates to a method of purification based on the principle of exposure of the water stream to UV light, with a wavelength of 254 nm. Living (micro) organisms are killed by this.

Purification unit 28 is a unit in which reverse osmosis is achieved.

On the basis of an input purity, that is, the purity of the water to be purified, and a target purity, that is, the purity of the finally purified water, a certain combination of purification units is selected and tested in practice. Should it be found that the target purity is not achieved, which may not only mean that the purity of the purified water is smaller than the purity, but also that the purity of the purified water is greater than the purity, a other combination of purification methods tested in practice.

With the change of the cascade combination, the results already obtained with the first cascade combination can be involved in the choice of the next cascade combination.

In practice it has been found that a test installation with a capacity of approximately 1000 liters per hour provides a sufficient scale, on the basis of which an extrapolation to a purification plant can take place on a full scale. In this connection, it should be noted that the flow rate is equal to the capacity of the test installation. Partial flows and / or circulation flows may exist per purification unit that are larger or smaller.

In the preferred embodiment of figures 1 and 2, purification of a water stream is involved. However, it is equally conceivable to clean streams other than water stream.

The present invention is not limited to the described preferred embodiments thereof; the rights sought are defined by the following claims, within the scope of which many modifications can be envisaged.

1017428

Claims (13)

5 A method for testing the purifying power of combinations of a number of purification methods for purifying a fluid, comprising: 10. supplying a fluid to be purified; - purifying the supplied fluid in a combination of purification methods; - discharging the purified fluid; - determining the purity of the purified fluid for the combination of purification methods; characterized by repeating the steps of supplying fluid to be purified, purifying fluid, draining the fluid and determining the purity of the fluid for one or more other combinations of purification methods; and deriving from the purities determined for the various combinations of purification methods the purifying power of each of said combinations of purification methods. 2. Device for testing the purifying power of combinations of a number of purifying units for purifying a fluid, comprising: - a feed for supplying a fluid to be purified; - purifying means connectable to the supply for purifying the supplied fluid; - drain connected to the purification means for discharging purified fluid; Wherein the purifying means comprise: - two or more purification units for purifying the fluid in two or more purification methods; characterized by 1017428 - guiding means for guiding the fluid from the supply through a first combination of series-connected purification units to the output and subsequently guiding the fluid from the supply through a second combination of series-connected purification units to the output; determining means for determining the purities of the fluid purified by the first combination as well as the second combination of purification units at one or more positions. Apparatus for testing the purifying power of a number of purifying units for purifying a fluid, preferably according to claim 2, comprising: 15. a supply for supplying a fluid to be purified; - purifying means connectable to the supply for purifying the supplied fluid; drain 20 connected to the purification means for discharging purified fluid; the purifying means comprising: - a first purification unit for purifying fluid according to a first purification method; - a second purification unit for purifying fluid according to a second purification method; - guide means for guiding the fluid from the supply via a series connection from the first and second purification unit to the output; determining means for determining the purity of the fluid at one or more positions. characterized in that the guide means are also adapted to guide the fluid from the supply through the first purification unit to the outlet and / or to guide the fluid from the supply through the second purification unit to the outlet. Device according to claim 2 or 3, wherein the capacity is in the order of magnitude of 1000 liters per hour. 1017428 Device as claimed in claim 2, 3 or 4, wherein the supply comprises a storage device for storing the fluid. Device as claimed in claim 2, 3 or 4, 5, comprising a stirring mechanism for keeping the fluid in the storage member in motion. Device as claimed in claim 5 or 6, wherein the storage member has a conical bottom. 8. Device as claimed in any of the claims 2-7, 10 comprising adding means for adding additives to the supplied fluid. 9. Device as claimed in any of the claims 2-8, wherein a purification unit comprises: - mechanical filtration means for removal of relatively coarse parts from the fluid; bag filter filtration means for removing smaller parts from the fluid; - sand bed filtration means for removing relatively fine parts from the fluid; 20. microfiltration means for removing microfine portions from the fluid; aerobic treatment agents for degradation of organic substances in the fluid; adsorbents for removal by adsorption of parts of a desired type; ion exchange means for removing ions of a desired type; - disinfectants for removal of microbiological contamination; and / or 30. reverse osmosis means for removing further parts from the fluid. Device as claimed in any of the claims 2-9, wherein the test device is reduced in scale, preferably by a factor of two or more, with respect to a water purification plant. An assembly for testing the purifying power of purifying units for purifying a fluid, comprising: 1017428 - a container; - a device arranged in the container according to any one of claims 2-10; - connections 5 provided in the container wall for the supply and discharge. 12. Assembly as claimed in claim 11, comprising control means for controlling the guide means and purifying means from outside the container. 13. Method as claimed in claim 1, wherein a device or assembly according to one of claims 2-11 is applied. 1 01 7426