NO345683B1

NO345683B1 - A mineral filter unit to filter water containing dissolved heavy metals, a mineral filter system and a method to filter water containing dissolved heavy metals through a mineral filter system

Info

Publication number: NO345683B1
Application number: NO20191423A
Authority: NO
Inventors: Nils-Per Sjåstad
Original assignee: Stadpipe As
Priority date: 2019-12-02
Filing date: 2019-12-02
Publication date: 2021-06-14

Description

TITLE:

A mineral filter unit to filter water containing dissolved heavy metals with a filter inlet end and a filter outlet end wherein water enters on filter inlet end and leaves on the filter outlet end and; a mineral filter system to filter water containing dissolved heavy metals and; a method to filter water containing dissolved heavy metals through a mineral filter system

Field of the invention

The present invention relates to a filter unit, system, and method to filter water containing heavy metals.

The present invention relates to a filter unit to filter water containing heavy metals with a filter inlet end and a filter outlet end wherein water enters on filter inlet end and leaves on the filter outlet end. The present invention also relates to a filter system to filter water containing heavy metals. The present invention further relates to a method to filter water containing heavy metals through a filter system.

Background of the invention.

Filtering of water is well known in the art. It is the process of removing undesirable contaminants from the water. The present invention focuses upon the reduction of heavy metals in water to an acceptable level to meet the requirements due to health requirements and/or local regulations. The invention is focused upon the reduction of heavy metals on the industrial level but could be used to filter water for home usage.

A common for removal of heavy metals is through the use of chemicals. Regardless its efficiency in comparison with other techniques, it can be a serious threat for the environments and the surrounding in-contact habitats. In aquaculture environments, these chemicals may put fish in danger to being poisoned. Death of fish has both an environmental impact, but also a financial one. It can be difficult to prevent a chemical from leaving the filter unit without extra steps and equipment in order to remove the chemical itself. This means that it is much easier for the chemical to escape into the environment.

Additionally, there is a problem with filtering more than a single heavy metal from the water. Filters are available that use multiple media in a single filter. This leads to disposal problems as different filter media need to be disposed in different ways. This can lead to extra expense as the disposal of the contaminant in the filter media will have to occur at the price of the most expensive contaminant. Another problem with the current filter media systems is that they are not able to provide efficient throughput. The lack of modular design removes the option of fine tuning the filter media amount and type depending upon a desired flow rate.

Another problem with the current design of filtering systems is that it is easy for the water to bypass a great deal of the filter media. It is not unusual for water to find paths through the filter media such that only 30% of the media is used. This results in a large waste of both material and associated costs. Additionally, it increases the size of the filter units (and associated systems) in order to compensate for the bypassing property of water.

Yet another problem with the current filtering systems is that changing of water purity concentration regulations can require a lot of work in order to retool and redesign the system. Most filter systems are designed for a specific purpose and do not have flexibility if a customer suddenly requires a different heavy metal to be removed.

The standard meaning of heavy metals is being used. Note that this is a short summary of the term and some important examples. The term has a well known meaning in the art. Heavy metals are generally defined as metals with relatively high densities, atomic weights, or atomic numbers. A wide ranges of elements in the periodic table are considered as heavy-metals, although there are several differentiations upon the importance of each heavy-metal class e.g. radioactivity, density, molecular weights, toxicity and so on. With regards to water science, an easier classification can be used that must meet the available water-quality standard like WHO.

With respect to water regulations, the term heavy metal refers to any metallic chemical element that has a relatively high density and is toxic or poisonous at low concentrations. Examples of some of the most important heavy metals are: mercury (Hg), cadmium (Cd), arsenic (As), chromium (Cr), thallium (Tl), lead (Pb), Iron (Fe), Manganese (Mn), Cupper (Cu), Zink (Zn), Silver (Ag), Cobalt (Co), and Nickel (Ni).

The acceptable concentration of these elements will be dependent upon the task. These regulations are known and are often changing.

An interested reader can consult a number of patent documents. FR 2870466A1 discloses a biofilter which uses microorganisms to remove suspended solids. US 5084175A discloses a filter for pool filtering of particulate and sediment. KR 20160138763A discloses a filter for wastewater filtration through the use of a membrane. DE 19504697A1 discloses a system for filtering of drinking water using separation. GB 2276330A discloses another pool filter that is similar to US 5084175A.

Objects and Advantages of the present invention

The present invention solves the above mentioned problems. One skilled in the art will also note that the present invention also provides other advantages and solves other technical problems than those that are explicitly disclosed above.

As chemicals can be very dangerous in aquatic environments, the present invention is focused upon the use of minerals. These remove the heavy metals in a different manner, are easier to form in a desired shape, and are easier to prevent from leaving the filter unit and escaping into the environment. If a mineral does escape into the environment it will usually be safer than a chemical that can perform the same heavy metal filtering.

The efficiency of the filter media’s ability to remove heavy metals from water is increased in at least two ways. The first is through designing of a filter unit such that the water is forced to pass through most, if not all, of the filter media. Another way is to design the components of the system such that the heavy metals form complexes. These complexes are larger and/or have more charge than the heavy metal by itself; making it easier for the filter media to remove the heavy metal. One way of forming these complexes is to add oxygen containing fluids to the system.

The filter unit of the present invention is of modular design. This allows for a customer to change the types of heavy metals that are removed without expensive costs of a re-design. If the heavy metals in the water changes, a new or additional filter unit can easily be added to the system. This gives the end user a great deal more control over the water quality compared to existing systems.

Short summary of the invention

In the first aspect, the present invention relates to a filter unit which is described by comprising:

a filter body;

one or more filter media;

a filter area;

a filter gap;

wherein:

the filter area is defined by the area between an filter inlet media retainer and the filter outlet media retainer; wherein:

the filter media retainers are arranged within the filter body such that water can flow through the filter area;

the filter inlet media retainer is arranged toward the filter inlet end and an filter outlet media retainer is arranged toward the filter outlet end; the filter media is arranged within the filter area such that the filter media does not exit the filter area;

the filter gap is arranged adjacent to and outside of the filter area; and the water entering the filter unit can pool within the filter gap.

An embodiment of the first aspect further comprising a filter port arranged on the filter body such that it provides access to the water in the filter unit, preferably to the filter gap.

An embodiment of the first aspect wherein the filter gap is arranged between the filter outlet end and the filter area.

An embodiment of the first aspect wherein the height of the filter area is between 150% and 450%, preferably between 200% and 400% of the height of the height of the filter gap.

An embodiment of the first aspect wherein height of the filter area 39 is between 50% to 90%, preferably between 60% and 80% of the height of the filter body 36.

An embodiment of the first aspect wherein the filter media is olivine.

An embodiment of the first aspect wherein the filter inlet media retainer is arranged at the filter inlet end.

In the second aspect, the present invention relates to a filter system which is described by comprising:

an inlet unit comprising an inlet end and a water inlet arranged upon an inlet body;

wherein water enters the filter system through the water inlet;

an outlet unit comprising an outlet end and a water outlet arranged upon an outlet body;

wherein water exits the filter system through the water outlet;

a filter unit according to the first aspect or embodiments thereof wherein,

the filter unit is arranged between the inlet unit and the outlet unit.

An embodiment of the second aspect wherein:

the inlet unit further comprises an inlet body and an inlet port arranged upon the inlet body such that it provides access to the water in the inlet unit; and/or the outlet unit further comprises an outlet body and an outlet port arranged upon the outlet body such that it provides access to the water in the outlet unit; and/or

the filter unit according to the first aspect or embodiments thereof which comprises a filter port arranged on the filter body such that it provides access to the water in the filter unit, preferably to the filter gap.

An embodiment of the second aspect wherein the filter system comprises two or more filter units arranged such that the filter inlet end of a first filter unit is in contact with the filter outlet end of a second filter unit.

An embodiment of the second aspect wherein the water inlet is arranged below the water outlet.

An embodiment of the second aspect wherein the inlet unit, outlet unit, an filter unit are held together using an assembly mechanism, preferably a plurality of clamps on the connections between the units.

An embodiment of the second aspect wherein:

the inlet unit further comprises a inlet air space wherein air is mixed with water inside the inlet unit; and/or

the outlet unit further comprises an outlet air space wherein air is mixed with water inside the inlet unit.

An embodiment of the second aspect wherein:

the height of the inlet air space is been 50% and four times, preferably between 75% and three times, most preferable between one and two times the diameter of the water inlet and/or

the height of the outlet air space is been 50% and four times, preferably between 75% and three times, most preferable between one and two times the diameter of the water outlet.

An embodiment of the second aspect wherein the filter inlet media retainer, filter outlet media retainer, inlet end, and/or outlet end comprises a grating with a plurality of circular openings, each with a diameter of between 50% to 250%, preferably between 100% and 200% of the diameter of the water inlet.

In the third aspect, the present invention relates to a method to filter water containing heavy metals through the any of the second aspects of the invention which is described by comprising the following steps:

1) obtaining a filter system according to the second aspect or any of the embodiments thereof and a filter unit according to the first aspect or any of the embodiments thereof;

2) allowing water to enter the filter system through the water inlet;

3) allowing water to exit the inlet unit through the inlet end and into the filter unit;

4) allowing water to enter the filter unit through the filter inlet end; and then a. allowing the water to travel through the filter media and pool in the filter gap; and/or

b. allowing the water to pool in the filter gap and then travel through the filter media;

5) allowing the water to exit the filter unit through the filter outlet end;

6) repeating steps 4-5 until the water exits all of the filter units;

7) allowing the water to enter the outlet unit through the outlet end;

8) allowing the water to exit the outlet unit through the water outlet.

An embodiment of the third aspect further comprising the step of measuring water characteristics through the before the water inlet, after the water outlet, within the inlet port, within the outlet port, and/or within the filter port, after or before any or all of the steps 1-8.

An embodiment of the third aspect further comprising repeating the steps until the water has the desired characteristics.

An embodiment of the third aspect further comprising the step of adding a fluid, preferably a fluid containing oxygen to the water through one more of the inlet port, outlet port, and/or filter port.

An embodiment of the third aspect wherein one or more filter units can be removed independently from the system and one or more filter units can be independently added to the system.

An embodiment of the third aspect wherein the flow of water through the filter system is temporarily stopped during one or more steps.

Concise Summary of the Invention

A filtering system to reduce heavy content of contaminated water will be disclosed. This is accomplished by bringing water into the system through the inlet unit, and through one or more filter units, and finally leaving the system through the outlet unit. A method for using the system was further disclosed.

The filter units will also be disclosed. The filter units contain a filter media to reduce the heavy metal content. The filter media is prevented from leaving the filtering area. This creates a filter gap inside of the filter unit where there is no filter material. This filter gap increases the efficiency of heavy metal removal by the filter media.

Brief description of the figures

The above and further features of the invention are a set forth with particularity in the appended claims and together with advantages thereof will become clearer from consideration of the following detailed description. Embodiments of the present invention will now be described, by way of example only, with reference to the following diagrams wherein:

FIG 1A discloses a perspective view of an embodiment of the system without filter media.

FIG 1B discloses a perspective view of an embodiment of the system with filter media.

FIG 2A discloses a longitudinal cross section of the embodiment of FIG 1B.

FIG 2B discloses an enlarged cross section of a connection between two filter units. FIG 3A discloses a perspective view of an embodiment of the filter unit.

FIG 3B discloses a cross section of the embodiment of FIG 3A.

FIG 3C discloses a perspective view two filter units in a stack.

FIG 4A discloses a perspective view of a preferred embodiment of an inlet unit. FIG 4B discloses a cross section of a preferred embodiment of the filter unit.

FIG 5A discloses a perspective view of a preferred embodiment of an outlet unit. FIG 5B discloses a cross section of a preferred embodiment of an outlet unit.

FIG 6 discloses the results of an experiment into how the removal percentage of olivine as a filter media 32 to different heavy metals is affected by the pH.

Reference Numbers and the Corresponding Annotations:

1 Inlet Unit

11 Inlet Air Space

15 Inlet Port

16 Inlet Body

18 Inlet End

181 Inlet End Opening

19 Water Inlet

2 Outlet Unit

21 Outlet Air Space

25 Outlet Port

26 Outlet Body

27 Outlet End

271 Outlet End Opening

29 Water Outlet

3 Filter Unit

31 Filter Gap

32 Filter Media

33 Filter Inlet Media Retainer

331 Filter Inlet Media Retainer Opening

34 Filter Outlet Media Retainer

341 Filter Outlet Media Retainer Opening

35 Filter Port

36 Filter Body

37 Filter Inlet End

38 Filter Out End

39 Filter Area

4 Assembly Mechanism

100 Filter System

Detailed description of the invention

Reference will now be made in detail to the present embodiments of the inventions, examples of which are illustrated in the accompanying drawings. Alternative embodiments will also be presented. The drawings are intended to be read in conjunction with both the summary, the detailed description, and an any preferred and/or particular embodiments, specifically discussed or otherwise disclosed. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided by way of illustration only. Several further embodiments, or combinations of the presented embodiments, will be within the scope of one skilled in the art.

Directional terms such as up, down, left, right, above, below, etc. are being used in reference to the orientation of the elements in the figures. In no way is this intended as limiting.

Reference is made to FIG 1A and FIG 1B. These figures disclose a perspective view

of a preferred embodiment of the system with and without filter media. Water will enter the system through the inlet unit 1, through one or more (three in this figure) filter units 3, and exit the system after passing through the outlet unit 2. In the preferred embodiment, an assembly mechanism 4 is used to hold the inlet unit 1, outlet unit 2, and filter units 3 together. To filter heavy metals from the water, a filter media 32 is arranged inside of the filter units 3. This will be discussed later.

While it is possible to simply bolt the units 1,2,3 together, another kind of assembly mechanism 4 is preferred. It is expected that during operation, that the filter units 3 are going to be changed more often than the inlet unit 1 or the outlet unit 2.

Additionally, the user should have the ability to add, remove, and exchange filter units 3 from the filter system 100 in an easy and fast manner. To that end, an assembly mechanism 4 is which preferably allows for the units 1,2,3 to be sufficiently tight together prevent water leaking from the system, but can be easy separated. The assembly mechanism 4 shown is a series of clamps that go around where the units 1,2,3 are in contact with each other.

Reference is made to FIG 2A. This figure discloses cross section view of the embodiment of FIG 1B. Water enters the inlet unit 1 through the water inlet 19 (not shown) and leaves the inlet unit 1 through the inlet end 18. The water will then enter the filter unit 3 on the filter inlet end 37 and exit on the filter outlet end 38. The water then enters the filter outlet unit 2 on the outlet end 27.

A filter media 32 is arranged between a filter inlet media retainer 33 and a filter outlet media retainer 34 where are adapted to prevent the filter media 32 from leaving the filter unit 3. The area between the filter inlet media retainer 33 and the filter outlet media retainer 34 is defined as the filter area 39. In other words, the filter media 32 is contained within the filter area 39. This creates a filter gap 31 between the filter area 39 and the filter outlet end 38. Note that while the filter media 32 can entirely fill the filter area 39, this is not a requirement.

Note that while the figures disclose a inlet media retainer 33 and an outlet media retainer 34 with a round opening 331,334, this is not a requirement. The only requirement is that the retainers 33,34 have to be able to hold the filter media 32 within the filter area 39 and allow water to flow through the filter unit 3 at a desired rate.

The filter media 32 is chosen such that particular contaminants can be removed from the water. Different contaminants may be filtered better with different filter media. In such a way, a series of filter units 3 with different filter medias 32 can be arranged to remove the specific heavy metals and other pollutants that are in the water. Once a filter media 32 can no longer filter the water to the desired level, it can be removed from the system by removing the filter unit 3 and replacing it with a new filter unit 3.

Additionally, the filter media 32 will be chosen based upon the operation parameters required to meet a customer’s needs. The conditions of the water affect the choice. These conditions include, but are not limited to the pH, pressure, temperature, flow rate, concentration of the contaminates, and required flow rate. Additionally, the properties of the filter media 32 itself play a role. These include, but are not limited to particulate size, pore size, hydraulic conductivity, particle charge, residence time of the water within the filter media 32 absorption capacity of the mineral, cost and availability of the filter media 32, effective removal rate.

A non-exhaustive list of preferable filter media 32 includes Olivin, Granulated Active Carbon, Potassium Permanganate, Silica-filter Sand, Quartz Sand, Anthracite, Silica, Manganese Dioxide, Clinoptilolite, Activated Carbon, Calcium Carbonate (Limestone), Clay and Expanded Clay, Aluminiumpillared-layered Montmorillonites, Kaolinite, and Goethite.

Other common filter media 32 that may work but may be less desirable include: Montmorillonite, Jordanian Bentonite, Verde-lodo Bentonite, Activated Bentonite, Chitosan-coated Bentonite, Mixture of Iron Pillared Layered Montmorillonite (80%) and Goethite (20%), Magnetite Nanoparticles, Hexagonal Birnessite, Hexagonal Birnessite Hydrous Mnoxide (HMO)-coated Clay, Camontmorillonite, Namontmorillonite, Heated Ball Clay Combination of Montmorillonite and Humic Acid, Acid-activated Form Kaolinite, Illite, Synthetic Magnesium Aluminium Layered Double Hydroxides Modified Palygorskite, Palygorskite-iron Oxide Nanocomposite, Fe-oxide Modified Smectites (Montmorillonite and Saponite) , Amine-magnetic Feoxide, Mixture of Goethite, Humic Acid and Kaolinite. This will be discussed further when presenting FIG 6.

The definition of heavy metals was discussed previously and is well known in the art. By changing the filter media 32 it is possible to remove a wide range of heavy metals depending upon the filter media 32 chosen and the number of filter units 3 used in the filter system 100. It is important to note that the previous list is for metals that suit the particular kinds of water that the filter system 100 is intended to be used with. Different kinds of applications may need to focus upon other kinds of heavy metals.

Finally, the water will exit the system through the water outlet 29 (not shown). A set of clamps act as the assembly mechanism 4 to hold the inlet unit 1, outlet unit 2, and filter unit(s) 3 together.

One of the purposes of the filter gap 31 is to prevent water from establishing only a few paths through the filter media 32. In normal operation of a filter, the water flows through in streams. This allows the water to bypass most of the filter media 32 by traveling at the edges and/or the through the middle of the filter media 32. However, in the present invention, the water will pool in the filter gap 31, and then flow into the next filter area 39 evenly. More of the filter media is used.

Depending on how the filter units 3 are connected to another unit, the inlet portion of that unit may protrude into the filter unit 3 on the filter outlet end 38. For example, in the embodiment shown, the second filter unit’s filter inlet end 37B protrudes into the first filter unit’s filter outlet end 38A. In such a case, the filter gap 31 would be considered to be between the filter area 39 of the first filter unit and the second filter unit’s filter inlet end 37B.

Reference is made to FIG 2B. This figure is a close up of the region N defined in FIG 2A wherein two filter units 3A and 3B are connected together by an assembly mechanism 4. The filter units 3A and 3B are arranged such the first filter unit 3A can stack upon the second filter unit 3B by the connection between the filter inlet end 37B of the second filter unit 3B making contact with the filter outlet end 38A of the first filter unit 3A.

In this manner, water flowing will pass through the filter media 32A of the first filter unit 3A, enter into the filter gap 31A of the first filter unit 3A, and subsequently enter the filter media 32B of the second filter unit 3B. In this way, the water is filtered by a filter unit 3A, before entering the next filter unit 3B, with a filter gap 31A between the first filter media 32A and the second filter media 32B. Note that the filter outlet media retainer 34A of the first filter inlet 3A prevents the filter media 32A from entering into the filter gap 31A from the inlet side of the first filter unit 3A, while the filter inlet media retainer 33B prevents the media from entire the filter gap 31A from the inlet side of the second filter unit 3B.

The assembly mechanism 4 is arranged such that it places force upon a portion of the filter outlet end 38A of the first filter unit 3A that is in contact with the filter inlet end 37B of the second filter unit 3B.

Reference is made to FIG 3A and FIG 3B. These figures discloses a preferred embodiment of the filter unit 3. The filter unit 3 comprises a filter body 36 with a filter inlet end 37 and a filter outlet end 38. The filter inlet end 37 and the filter outlet end 38 is the direction from which water will enter and exit the filter unit 3, respectfully. A filter area 39 is defined as the area between the filter inlet media retainer 33 (toward the filter inlet end 37) and the filter outlet media retainer 34 (toward the filter outlet end 38). A filter gap 31 is arranged between the filter area 39 and the filter outlet end 38.

The optimal size of the filter gap 31 to the filter area 39 is dependent upon a large number of factors. Note that when height of the filter area 39, the filter gap 31, or the filter body 36 is discussed this is in reference the cross sectional heights as disclosed in FIGs 2A, 2B, and 3B. Calculations have shown that the for common conditions that it is expected that the filter system 100 can experience that height of the filter area 39 is between 150% and 450%, preferably between 200% and 400% of the height of the height of the filter gap 31. In some situations, it is better to relate the height of the height of the filter area 39 to the height of the filter body 36.

Calculations have shown that height of the filter area 39 is preferably be between 50% to 90%, preferably between 60% and 80% of the height of the filter body 36.

Of course, depending on the scale of implementation for this filter which also highly related to our customer needs, these ranges could change and have in different optimum ranges.

In a preferred embodiment, a filter port 35 is arranged upon the filter body 36. This filter port 35 allows for access to the water in the filter unit 3 without having to disassemble the filter unit 3 or the filter system 100, or any resulting leakage that may occur from sampling the water in the filter unit 3. It is also preferable that the filter port 35 is arranged such that it can access the water in the filter gap 31 because there is no filter media 32 (or very little) in this portion of the filter unit 3.

When taking a water sample, this would make it easier to achieve accurate readings (the filter media 3 will have a higher concentration of the contaminants than the water in the filter gap 31 due to the filtering process). The filter port 35 can also be used to add supplements to the water. For example, the efficiency of the filtering could be increased by injecting oxygen-containing fluids (preferably air) into the filter port 35. Another advantage of having the filter port 35 in the filter gap 31 is that during processes of adding supplements in the water, the filter media is not disturbed. While this filter port 35 has advantages, the filter unit 3 will function without it.

Oxygen can greatly increase the efficiency of the filter system 100. Part of this is due to how heavy metals interact with oxygen in an aqueous environment. The dissolved heavy metal ions will form a metal oxide in the presence of oxygen by an oxidative process. What is surprising is that multiple heavy metals ions in a will adsorb to the surface of a heavy metal oxide. This is known in chemistry as Surface Complexation. In such a manner, the heavy metal oxide will aid in filtering out the heavy metal dissolved in water. In other words, the more heavy metal oxide, the more efficient the removal of the heavy metal ions will be.

While the filter medias 32 can and do remove heavy metal ions directly, it is more efficient to remove the complexes of larger heavy metal oxide with the adsorbed heavy metal ions. This can be due to the larger size of the complex makes it physically easier for the filter media 32 to latch onto the complex. It can also be due to the fact that the complex will take more time to travel through the filter media 32 than a smaller heavy metal ion, thus increasing retention time inside of the filter unit 3. An advantage, but not a requirement, of operating the system in a “bottom up” manner (where the inlet unit 1 is on the bottom and the outlet unit 2 is on the top) is that this will increase the chance of surface complexation.

The complexes can be become trapped within the filter media 32 by a direct chemical bond between the heavy metal ions or complexes and the filter media. This is known as chemisorption. Additionally, the complexes can be physical adsorbed in the pores and on the surface of the filter media 32. The preferred filter media 32 were chosen to maximize one or both of these trapping methods.

While it is preferable to add air (or other oxygen containing fluids) to the filter port 35 other materials and gasses could be added as well. The function of these would be to increase the efficiency of the filtering of the heavy metals inside of the filter unit 1. This could be, for example, by increasing the size of the complexes that are formed and the charge on the complex. Another reason for adding another fluid to the filter unit 3 is to increase the amount of oxygen that can dissolve in the water. Nitrogen is a common gas that would perform this task. More than one fluid can be injected through the same port, but it is preferable that at least one of them contains oxygen.

FIG 3C discloses a perspective view of two filter units in a stack. As in FIG 2B, a first filter unit 3A and a second filter unit 3B that are assembled together. In this embodiment, the filter outlet end of the first filter unit 37A is adapted such that the filter inlet end of the second filter unit 3B fits inside of it. Preferably, the two filter units 3A,3B have the same shape in order to reduce production costs. However, this construction is not required. It is important that when assembled, the filter units 3A,3B prevent the water from escaping between the filter units 3A,3B. This can be done through mated connections as shown in the figures or through sealing elements (such as gaskets) between the filter units 3A,3B.

FIGs 4A and 4B disclose a perspective view and a cross sectional view, respectively, of the preferred embodiment an inlet unit 1. The water enters the inlet unit 1 through the water inlet 19 (e.g. a pipe) and exits on the inlet end 18. The inlet unit 1 also comprises an inlet body 16. Arranged upon the inlet body 16 is an inlet port 15. As with the filter port 35, an inlet port 15 allows for access to the water within the inlet unit 1 without disassembling the inlet unit 1 or the filter system 100. It is preferable that within the filter unit 1 there is an inlet air space 11. This inlet air space 11 is a region or regions wherein air is available to mix with water that is within the inlet unit 1. The air will allow for better agitation of the water within the inlet unit 1. Additionally, this will expose the water to oxygen and increase the efficiency of the heavy metal filtering within the filter units 3.

There can be more than one inlet air space 11 within the inlet unit 1. This inlet air space 11 can be formed through the insertion of an oxygen containing fluid (e.g. air) into the inlet unit 1 through the inlet port 15, by oxygenating the water before it enters the water inlet 19, or through how the filter system 100 is assembled. Normally the inlet air space 11 will be present if the filter system 100 was not constructed under vacuum as air is usually within the filter unit 1 before water is brought into the inlet unit 1. The inlet unit 1 will function without the inlet air space 11 and the inlet port 15.

The height of the inlet air space 11 for convenience can be related to the size of the water inlet diameter 19. Note that by “height” we are referring to the height of the inlet air space 11 from a cross sectional view (e.g. FIG 4B). This height in reality defines a volume that would correspond to the product of the cross sectional area of inlet unit 1 and the height of the inlet air space 11. Calculations have shown that the height of the inlet air space 11 is effective been 50% and four times, preferably between 75% and three times, most preferable between one and two times the diameter of the water inlet 19.

FIGs 5A and 5B disclose a perspective view and a cross sectional view, respectively, of the preferred embodiment an outlet unit 2. The water enters the out unit 2 through the outlet end 27 and exits through the water outlet (e.g. a pipe) 29. The outlet unit 2 also comprises an outlet body 26. Arranged upon the outlet body 26 is an outlet port 25. As with the filter port 35 and the inlet port 15, an outlet port 25 allows for access to the water within the outlet unit 2 without disassembling the outlet unit 2 or the filter system 100. It is preferable that within the outlet unit 2 there is an outlet air space 21. This outlet air space 21 is a region or regions wherein air is available to mix with water that is within the out unit 2. The air will allow for better agitation of the water and exposure the water to oxygen within the out unit 2. In the case where the water that exits the outlet unit 2 is recirculated through the filter system 100, this outlet air space 21 will increase the efficiency of the heavy metal filtering within the filter units 3.

In a similar manner to the inlet air space 11, the outlet air space 21 can be defined in terms of the diameter of the water outlet. Calculations have shown that the height of the outlet air space 21 is effective been 50% and four times, preferably between 75% and three times, most preferable between one and two times the diameter of the water outlet 29. The same definition of “height” is used for the outlet air space 21, as for the inlet air space 11.

Olivine is a filter media 32 which is preferable. It can absorb a wide range of heavy metals at common operational conditions for purification of sea water. Additionally, it is readily available in Norway. Figure 6 discloses its effectiveness for removal of cadmium, copper, and lead. Further, Table 1 below shows the effectiveness of olivine for some common heavy metals found in water. Note that this is not an exhaustive list. Olivine can also be used to filter iron from water.

Table 1 – Heavy Metal Removal using Olivine in the Filter System 100

Some of the factors that determine the filter media 32 content are: water inlet pH, water inlet temperature, water inlet composition, heavy-metals concentrations, mineral adsorption capacity, mineral size, mineral arrangement, mineral heavy-metal removing capability, the required residence in-contact time (between mineral surface and water drop), and the expected end results determined by the customer needs. Customer needs can include the concentration of heavy metals of the water leaving the outlet and required flow rate of the water through the system.

To select the best filter media 32 content, a matrix analysis of these above factors is considered together to decide the most optimum heavy metal removal. All of the required information can found in the literature.

While the embodiment of the system shown in FIGs 1A-2B show three filter units 3, this is by example only. At least one filter unit 3 is required, but more than one filter unit 3 is acceptable. It is understood that during operation, that more than one filter unit 3 may be required to remove different metals and/or provide acceptable level of filtration. The modular nature of the filter units 3 makes this easily adaptable by one skilled in the art.

Note that while all of the filter units 3 are shown with the same height, this is not a requirement. In alternate embodiments, different filter units 3 could have different heights. This could be a function of how much filter media 32 is needed for a particular flow rate, the retention time needed, and the concentration of pollutants in the water.

Another parameter than can preferably be associated with the size of the inlet diameter 19 are portions or the entirety of the inlet end 18, outlet end 27, filter inlet media retainer 33, and/or the outlet media retainer 34. In the preferred embodiment, the inlet end 18, outlet end 27, filter inlet media retainer 33, and/or the outlet media retainer 34 comprise a grating with a plurality of equal diameter circular through openings 181,271,331,341. The diameter of these openings 181,271,331,341 has a diameter of between 50% to 250%, preferably between 100% and 200% of the diameter of the water inlet (10). Note that while preferable, it is not required that each of the diameters of the openings on a single grating be equal. There may be situations where due to the parameters of the system there may need to be different sized openings on different locations of the grating. Additionally, while it is preferable that the diameter of the openings 181,271,331,341 are equal, this is also not a requirement. Different units 1,2,3 may require a different diameter of the opening 181,271,331,341 depending upon the operation of each unit. Please note that each individual of the filter units 3 within the filter system 100, may have a different sized openings 331,341 on its outlet media retainer 34 or filter inlet media retainer 33. Each of the units 1,2,3 may have a grating (or not) that has been described above independently of any of the others. It is also possible for a single filter unit 3 to have a different grating (or none at all) from another filter unit 3.

While the usual operation of the filter system 100 is for the inlet unit 1 to be located on the bottom of the filter system 100, it is possible for the inlet unit 1 to be located on the top of the filter system. It may be advantageous to use an alternate embodiment, where there is a filter gap 31 between the filter area 39 and the filter inlet end 37. This could increase efficiency by allowing the water to pool in this filter inlet end 37 side before continuing through the system. Another advantage is that it can increase the likelihood of surface complexation. Please note that this filter gap could be in addition to that between the filter area 39 and the filter outlet end 38. The figures presented show that the inlet side of the filter area 39 is near the filter inlet end 37, it is possible for there to be a gap between the filter area 39 and the filter inlet end 37.

The filter system 100 both in both preferable and alternate embodiments is operated by bringing water into the inlet unit 1 through the water inlet. The water will flow into the filter unit 3 where it will flow through the filter media 32 contained with the filter area 39 and into the filter gap 31. The water will pool into the filter gap 31 and then flow into the next filter unit 3 and the associated next filter media 32 and filter area 39. The water will then exit the filter system 100 through the outlet unit 2.

The water can be monitored to make sure that it has the desired characteristics. These characteristics will normally be a low enough concentration of heavy metals. The water samples can be taken through the inlet port 15, outlet port 25, and/or filter port 35. The characteristics can be monitored by the insertion of a measuring device into the inlet port 15, outlet port 25, and/or filter port 35. The water can be recirculated through the filter system 100 one or more times until the desired water characteristics are achieved. It is also possible for the flow of water to be stopped in order to increase the retention time within the filter system 100 to allow for more heavy metals to be removed. This can be determined automatically from measurements, or through operational practices.

During standard operation, when a filter unit 3 is no longer removing enough of a heavy metal from the system, it will be replaced. Due to the modular nature of the system, this will not be a difficult process. It is also possible to add one or more filter units 3 can be added to the filter system 100. For example, operational tolerances or the water composition changes such that another filter unit is needed to meet the new demand. This can also be due to needed another filter unit 3 with the same filter media 32 is required to removing a large quantity of a contaminant during operation without changing filters as often. It is also possible to remove filter units 3 from the filter system 100. It is also possible to run a filter unit 3 that does not contain a filter media 32. This can be useful if it is desired to keep total number of filter units 3 the same (perhaps to keep the same total length), but it is not needed that all of the filter units contain a filter media 32. Individual filter units 3 can be independently added, removed, or exchanged in the filter system.

As discussed above, things can be introduced into the filter unit 3 through the filter port 35 to increase filtering efficiency. As an alternative, or in addition, the inlet unit 1 can have things introduced through the inlet port 15 and/or the outlet unit 2 can have things introduced through the outlet port 25. This item is preferably an oxygen containing fluid. Also note that there are several types and names for a port 15,25,35. One such that is in common usage is “nipple”. However, as defined previously the port 15,25,35 is something that allows access to the water in the units 1,2,3.

Another way that the efficiency of the filtering can be obtained is by adding a backwash system to decrease the retention time while increase the filter efficiency. The most preferable embodiment of the invention will now be disclosed. One or more filter units 3 (as disclosed in FIGs 3A and 3B) are arranged in a stack (if two or more filter units 3, arranged as disclosed in FIG 3C). These filter units 3 are arranged on top of a inlet unit 1 (as disclosed in FIGs 4A and 4B). On top of the stack of filter units 3 is arranged an outlet unit 2 (as disclosed in FIGs 5A and 5B). During operation, water will enter the inlet unit 1 through the water inlet 19, flow upwards through the one or more filter unit 3, and exit the outlet unit 2 through the water outlet 29.

Modifications to the embodiments previously described are possible without departing from the scope of the invention as defined by the accompanying claims. Numerals included within parentheses in the accompanying claims are intended to assist understanding of the claims and should not be construed in any way to limit the subject matter claimed.

Claims

1. A mineral filter unit (3) to filter water containing dissolved heavy metals with a filter inlet end (37) and a filter outlet end (38) wherein water enters on filter inlet end (37) and leaves on the filter outlet end (38) CHARACTERIZED in that it comprises:

a filter body (36);

one or more filter media (32);

a filter area (39);

a filter gap (31);

wherein:

the filter media comprises a mineral;

the filter area (39) is defined by the area between a filter inlet media retainer (33) and the filter outlet media retainer (34); wherein:

the filter media retainers (33,34) are arranged within the filter body (36) such that water can flow into the filter inlet media retainer (33), through the filter area (39), and out of the filter outlet media retainer (34);

the filter inlet media retainer (33) is arranged toward the filter inlet end (37) and a filter outlet media retainer (34) is arranged toward the filter outlet end (38);

the filter media (32) is contained within the filter area (39) wherein the filter media (32) cannot exit the filter area (39) through the filter outlet media retainer (34);

the filter gap (31) is arranged adjacent to and outside of the filter area (39); and

the water entering the filter unit can pool within the filter gap (31).

2. The filter unit (3) according to any of the previous claims, further comprising a filter port (35) arranged on the outside of the filter body (36) such that the filter port (35) has an at least temporary fluid connection to the water in the filter unit (3), preferably to the filter gap (31).

3. The filter unit (3) according to any of the previous claims, wherein the filter gap (31) is arranged between the filter outlet end (38) and the filter area (39).

4. The filter unit (3) according to any of the previous claims, wherein the height of the filter area (38) is between 150% and 450%, preferably between 200% and 400% of the height of the filter gap (31).

5. The filter unit (3) according to any of the previous claims, wherein height of the filter area (39) is between 50% to 90%, preferably between 60% and 80% of the height of the filter body (36).

6. The filter unit (3) according to any of the previous claims, wherein the filter media (32) is olivine.

7. The filter unit (3) according to any of the previous claims, wherein the filter inlet media retainer (33) is arranged at the filter inlet end (37).

8. A mineral filter system (100) to filter water containing dissolved heavy metals CHARACTERIZED in that it comprises:

an inlet unit (1) comprising an inlet end (18) and a water inlet (19) arranged upon an inlet body (16);

wherein water enters the filter system (100) through the water inlet (19);

an outlet unit (2) comprising an outlet end (27) and a water outlet (20) arranged upon an outlet body (26);

wherein water exits the filter system (100) through the water outlet (20);

a filter unit (3) according to any of claims 1-7;

wherein,

the filter unit (3) is arranged between the inlet unit (1) and the outlet unit (2).

9. The filter system (100) according to claim 8, wherein:

the inlet unit (1) further comprises an inlet body (16) and an inlet port (15) arranged upon the outside of the inlet body (16) wherein the outlet port (25) has an at least temporary fluid connection to the water in the inlet unit (1); and/or

the outlet unit (2) further comprises an outlet body (26) and an outlet port (25) arranged upon the outside of the outlet body (26) wherein the outlet port (25) has an at least temporary fluid connection to the water in the outlet unit (2); and/or

the filter unit (3) according to claims 1-7 which comprises a filter port (35) arranged on the outside of the filter body (36) wherein the filter port (35) has an at least temporary fluid connection to the water in the filter unit (3), preferably to the filter gap (31).

10. The filter system (100) according to any of claims 8-9, wherein the filter system (100) comprises two or more filter units (3) wherein the filter inlet end (37A) of a first filter unit (3A) is in contact with the filter outlet end (38B) of a second filter unit (3B).

11. The filter system (100) according to any of claims 8-10, wherein the water inlet (19) is arranged below the water outlet (29).

12. The filter system (100) according to any of claims 8-11, wherein the inlet unit (1), outlet unit (2), an filter unit (3) are held together using an assembly mechanism (4), preferably a plurality of clamps on the connections between the units (1,2,3).

13. The filter system (100) according to any of claims 8-12, wherein:

the inlet unit (10) further comprises a inlet air space (11) wherein air is mixed with water inside the inlet unit (10); and/or

the outlet unit (20) further comprises an outlet air space (21) wherein air is mixed with water inside the inlet unit (20).

14. The filter system (100) according to any of claims 8-13, wherein:

the height of the inlet air space (11) is between 50% and 400%, preferably between 75% and 300%, most preferable between 100% and 200% of the diameter of the water inlet (19) and/or

the height of the outlet air space (21) is between 50% and 400%, preferably between 75% and 300%, most preferable between 100% and 200% of the diameter of the water outlet (29).

15. The filter system (100) according to any of claims 8-14, wherein the filter inlet media retainer (33), filter outlet media retainer (34), inlet end (18), and/or outlet end (27) comprises a grating with a plurality of circular openings (311, 341, 181, and/or 271), each with a diameter of between 50% to 250%, preferably between 100% and 200% of the diameter of the water inlet (10).

16. A method to filter water containing dissolved heavy metals through a mineral filter system (100) CHARACTERIZED in that it comprises the following steps:

1) obtaining a mineral filter system (100) according to any claims 8-15 and a mineral filter unit (3) according to any of claims 1-7;

2) allowing water to enter the filter system (100) through the water inlet (19); 3) allowing water to exit the inlet unit (1) through the inlet end (18) and into the filter unit (3);

4) allowing water to enter the filter unit (3) through the filter inlet end (37); and then

a. allowing the water to travel through the filter media (32) and pool in the filter gap (31); and/or

b. allowing the water to pool in the filter gap (31) and then travel through the filter media (32);

5) allowing the water to exit the filter unit (3) through the filter outlet end (38); 6) repeating steps 4-5 until the water exits all of the filter units (3);

7) allowing the water to enter the outlet unit (2) through the outlet end (27); 8) allowing the water to exit the outlet unit (2) through the water outlet (29).

17. The method according to claim 16, further comprising the step of measuring water characteristics before the water inlet (19), after the water outlet (29), within the inlet port (15), within the outlet port (25), and/or within the filter port (35), after or before any or all of the steps 1-8.

18. The method according to any of claims 16-17, further comprising repeating the steps until the water has the desired characteristics.

19. The method according any of claims 16-18, further comprising the step of adding a fluid, preferably a fluid containing oxygen to the water through one more of the inlet port (15), outlet port (25), and/or filter port (35).

20. The method according to any of claims 16-19, wherein one or more filter units (3) can be removed independently from the system and one or more filter units can be independently added to the system.

21. The method according to any of claims 16-20, wherein the flow of water through the filter system (100) is temporarily stopped during one or more steps.

22. The filter unit (3) according to any of claims 1-7, wherein an oxygen containing fluid can be added to the water through the filter port (35).

23. The filter system (100) according to any of claims 9-15, wherein oxygen can be added to the water through the inlet port (15), the outlet port (24), and/or the filter port (35).

24. The method according any of claims 16-21, wherein the addition of the fluid contain oxygen increases the formation of heavy metal oxide complexes in the water.