WO2013141820A2

WO2013141820A2 - Fountain with safe drinking water

Info

Publication number: WO2013141820A2
Application number: PCT/SI2013/000014
Authority: WO
Inventors: Domen LEŠTAN; Gorazd LAKOVIČ; Marko Gerl; Neža FINŽGAR
Original assignee: Arhel, Projektiranje In Inženiring D.O.O.
Priority date: 2012-03-23
Filing date: 2013-03-21
Publication date: 2013-09-26
Also published as: SI24019A; WO2013141820A3

Abstract

Stationary and mobile embodiment of the water fountain for preparation of safe drinking water solves the problem of polluted tap water or water from sources where water quality control is not adequately assured. Removal of pollutants from drinking water in the container of the fountain is achieved in electrolytic cell with boron doped diamond anode. The required time of electrolysis is for expected water pollutant or mixture of thereof specified in the operating system of the device. The stationary embodiment of the fountain enables continuous refill of the container from the working vessel and allows consumer the uninterrupted supply of safe clean water. The mobile embodiment of the fountain operates in a batch mode in three cycles: water cleaning, water availability, and the cycle of cleaning of device. Existing drinking fountains can be converted into fountains according to invention by replacing old with new components according to invention.

Description

FOUNTAIN WITH SAFE DRINKING WATER

The invention relates to the device "Fountain with safe drinking water" with function of removal of water pollutants in the water container of the fountain. Pollutants are removed by electrochemical oxidation using boron doped diamond anode and by electro-precipitation of metals on electrodes. Use of safe, clean drinking water from the fountain is possible after sufficient water treatment time, pre-determined in accord with the type and concentration of pollutants in the source water, before treated water is fed into the container of the fountain.

In terms of invention, the device belongs to C02F 1/461 and C02F1 1/78B67D1/00 according to the international patent classification.

Nationals and international legislature on drinking water stipulate permissible concentrations of pollutants in tap and drinking water which are not necessary completely safe for human and animal consumption. Problematic are drinking waters from sources where water quality is not regularly monitored and controlled such are small and privately owned water sources, sources in remote locations and water sources in countries with poorly developed and controlled system of the water supply. Potentially hazardous are possible synergistic toxic effects of otherwise individually permissible concentrations of pollutants which are present in the water source simultaneously. Increasing problem are residuals of human and animal pharmaceuticals and phyto-pharmaceuticals in drinking waters and their biologically resistant metabolites which can act as hormone disruptors even in very low concentrations. Frequent problem is pollution of drinking water sources with fecal wastes and bacteria. Drinking waters sources in tropical countries are frequently contaminated with carcinogenic cyanotoxins. In tap-water preparation plants water is treated to comfort legislative requirements, jet only small portion of this water is used for human and animal consumption, where presence of pollutants is much more important than in other water uses. Novel device according to invention is stationary or mobile water fountain or water bar or water dispenser or water vending machine and provides for safe drinking water. CURRENT DEVICES FOR PREPARATION OF SAFE DRINKING WATER

Current devices for preparation of safe drinking water include:

a. Water fountain which uses UV-irradiation (U.S. Pat. No. 2011260077) and UV-irradiation in combination with active charcoal (U.S. Pat. No. 6953523).for degradation and removal of pollutants from water.

b. Water fountain which uses filtration (CN. Pat. No. 102115218; CN. Pat. No. 102115217; WO. Pat. No. 201 1 150604) and filter combined with absorbent for removal of toxic metals from drinking water CN. Pat. No. 201890819).

c. Water fountain which uses ozone for degradation and removal of pollutants (U.S. Pat. No.

8007666).

d. Water fountain which uses ozone and UV-irradiation, an advanced oxidation process, for degradation and removal of pollutants CN. Pat. No. 201890786; CN. Pat. No. 102060360). e. Water fountain which uses electrochemical processes, mostly electrochemical advanced oxidation processes where water is cleansed in the electrolytic cell with one or several anodes and cathodes (U.S. Pat. No. 5744028; U.S. Pat. No. 5647969; JP. Pat. No. 2000279964).

Among devices for preparation of safe drinking water devices which use electrochemical advanced oxidation processes for degradation and removal of pollutants are the most similar to the water fountain according to our invention. The main characteristics that distinguish the device according to our invention from known devices are:

a. In known devices water from tap, faucet, tank, container or other source flows through electrolytic cell only once. The device according to our invention is designed to circulate water between water container and working vessel until pollutants in the water are completely degraded and removed.

b. In known devices with single water pass through the electrolytic cell the water cleansing capacity is pre-determined by cell geometry, electrode materials, active electrode surfaces, electric current and potential between electrodes and contact time between treated water and electrodes. Insufficient capacity of these fixed parameters can results in incomplete pollutant degradation and removal. In the device according to invention the water-treatment capacity is not restrained and is regulated by increasing the number of water passes through the electrolytic cell by circulating water between the electrolytic cell and container or working vessel and thus increasing the water treatment time to comfort complete degradation of pollutants. In this way for the known volume of the water container and working vessel the required time of water circulation is pre-determined in advance for each pollutant separately, to ensure complete pollutant degradation and removal.

c. In known devices the mode and volume of drinking water to be taken from the device are not related to the water treatment process. In mobile embodiment of the device according to invention water can be taken from the container only after predetermined time of water treatment. After treatment time the whole volume of water in the container is available for consumption (except for the small volume of water which is used for device self-cleaning). When the volume of water in the container is spent the tank can be filled again from the Water source and new cycle of water treatment recommence. Stationary embodiment of the device according to invention enables continuous refill of the container with cleansed water from the working vessel and thus uninterrupted supply of safe water, i.e. for drinking and cooking.

d. In known device the time of water treatment and cleansing is pre-determined for each pollutant or mixture of thereof present or suspected to be present in the source water and up-loaded into the operational software system of the device.

e. None of the known water fountains uses boron doped diamond as anode material as is used in the water fountain according to invention. Boron doped diamond anode is chemically inert and thus safe for processing drinking water and has among all other known anode materials the highest over-potential for production of hydroxyl radicals for oxidative degradation of inert and resistant organic pollutants.

DESCRIPTION OF THE PREFFERED EMBODIMENT OF THE INVENTION

The preferred embodiments of device according to invention; water fountain, water bar, water dispenser or water vending machine is stationary as shown in Figure 1 and mobile as shown in Figure 2. Water fountain is comprised from water container 1, which can be in mobile embodiment separated from the device, exchanged and refilled from the water source. Water container 1 is in stationary embodiment of the device connected directly to water source and refilled through electro-magnetic valve 3. Container 1 can be equipped with gas exhaust 4 for removal of gases generated during electrolytic water treatment and to allow necessary air inflow when water from the container 1 is consumed. Device according to invention can comprise water cooling, heating and filtration systems as known to one skilled in the art. Water container 1 of device according to invention is with system of pipes and electromagnetic valve 5 connected to electrolytic cell 6 and settler 7 and with another electromagnetic valve 8 to the faucet 9 from which clean safe drinking water is consumed; for example to fill the drinking jar 10. Treated water is circulated by pump 12 from container 1 through the system of pipes which are connecting electrolytic cell 6, settler 7 and electromagnetic valve 11, back to the water container 1. Electrolytic cell is supplied with electric current from the power supply 13. Precipitate collected in container 1 and settler 7 is in mobile embodiment of the device removed through electromagnetic valve 14 into the waste-water vessel 15 which is periodically emptied. In the stationary embodiment of the device according to invention water circulates through systems of pipes through electrolytic cell 6, settler 7 and working vessel 16 which enables continuous refill of container 1 with the cleansed water. In stationary embodiment of the device precipitate collected in settler 7 can be flushed directly into the drain.

Stationary embodiment of the drinking fountain

In stationary embodiment of the device according to invention water cleansing commence when volume of cleansed water, taken from water container as shown in Figure 1, is equal or exceeding the volume of the working vessel 16. This is detected by optical or conductometric probe or other means known to one skilled in the art. Working vessel 16 with volume several- times smaller compared to volume of the water container 1 is filled from the water source through electromagnetic valve 3. During this operation all other valves except electromagnetic valve 8 remain closed. Supply of safe clean drinking water from container 1 remains uninterrupted. Once working vessel 16 is filled the water treatment cycle commences. During water treatment in the working vessel 16 only valves 5 and 8 are opened; water pump 12 and electric power supply 13 are operational. Water circulates through electrolytic cell 6 and settler 7 back to the working vessel 16. Electrolytic cell comprise one or more boron doped diamond anodes and one or more cathodes preferably made of titanium or stainless steel or other conductive materials known to one skilled in the art. Electrodes are positioned in mono or bi-polar mode, distance between electrodes vary between 0.5 and 10 mm. Electric current supply can be parallel or sequential, potential between electrodes between 0 and 40 V, electric current between 0.1 and 100 A. Electric current supply can be constant or pulsing. Conditions in electrolytic cell enable generation of hydroxyl radicals ·ΟΗ which are known to be capable of oxidative degradation and mineralization of organic pollutants and destruction of pathogenic bacteria and other microorganisms. In electrolytic cell metallic species are ionized and electro-participate. Boron doped diamond anode is chemically inert and does not interact in any way with drinking water. Hydroxyl radicals are short-lived and do pollute drinking water. During electrolysis oxygen 0₂ and hydrogen H₂ are formed and are removed from working vessel 16 and water container 1 through the gas exhaust 4, 17. The amount of generated gases is small due to the extreme > 3 V over-potential of boron doped anode before H₂ (cathode) and 0₂ (anode) formation. This electrolytic window allows for production of hydroxyl radicals directly from water with a high current efficiency according to equation:

H₂0→•OH + e^"+ H⁺

During electrolysis pH of the treated water increases which, however, does not affect the quality of the drinking water. On the contrary, drinking and cooking with slightly alkaline water has known therapeutic effects.

Water circulates between working vessel 16 and electrolytic cell 6 in the closed process loop until pollutants are completely degraded and removed. This is achieved by pre-determined time of water treatment, required for expected concentration of pollutant and mixtures of thereof in the source water in a given volume 1 - 10 L of the working vessel. The required cleansing times are pre-loaded into the operational software system of the water fountain according to invention. In some embodiment of the water fountain required cleansing time is selected automatically after pollutants present or suspected to be present in the source water are selected from the displayed menu. After water treatment is completed clean water from working vessel 16 is transferred into water container 1. During this process all valves except valve 11 remain closed, including valve 8 which remains closed only during clean water transfer process to avoid build of pressure on faucet 9. Stationary embodiment of the water fountain allow for continuous refill of the water container 1 and thus for un-interrupted supply of large quantities of safe clean water for consumer.

The self-cleaning of Water fountain is activated automatically after defined number of transfers of clean water from working vessel 16 into container 1. The defined number of water transfers, which triggers cleaning of the device depends and is determined from the volume ratio of working vessel 1 and container 1. Before cleaning of fountain commence the working vessel 16 is filled with water from the water source through valve 3 during which all valves except valve 8 remain closed; During cleaning of fountain all valves except valves 14 and 8 are closed. Valve 14 can be periodically opened for short time intervals. During cleaning of fountain the polarity of electrodes is reversed by electric power supply 13 and water from the working vessels flows through electrolytic cell 6 and settler 7 into the drain or in some embodiments into the waste water vessel 15. The current of flowing water washes particles and debris electrodeposited on electrodes and particles collected in settler 7. During cleaning of fountain the valve 8 remains open and the supply of safe clean drinking water for consumer is not interrupted.

Depiction of the device according to invention in Figure 1 is symbolic and does not represent limitation to embodiments of the water fountain. The water fountain can be self-standing or placed for example in the kitchen furniture cabinets. If device is placed beneath the kitchen desk and gravitational flow of water from the container 1 is not possible than water can be taken from the container by pumping or by other mean known to one skilled in art.

Mobile embodiment of the drinking fountain

Mobile embodiment of the drinking fountain according to invention, as shown in Figure 2, functions in a batch mode in three consecutive cycles: water cleansing, availability of safe drinking water for consumption, and cleaning of the fountain. Interruption of these cycles by consumer is prevented. Existing drinking fountains can be converted into fountains according to invention by replacing old with new components according to invention. .

In mobile embodiment of the device according to invention the water cleaning cycle commences when clean drinking water is spent from the container 1 and container is exchanged or re-filled with water from the source. During water cleaning cycle valves 5 and 1 1 remain open, valves 8 and 14 closed, water pum 12 and electric power supply 13 are operational. Water is circulated from and back to container 1 through electrolytic cell 6 and settler 7. Electrodes are placed and powered in the same way as in stationary embodiment of the fountain. The volume of the container is between 5 and 50 L; according to this volume the time required for degradation and removal of pollutants and mixtures of thereof is determined. The required treatment time is pre-loaded into the operational software system of the fountain according to invention and is selected automatically after pollutants present or suspected to be present in the source water are selected from the displayed menu.

In mobile embodiment of the fountain according to invention water can be taken from the container 1 only after water cleaning cycle is completed. After cycle is completed almost the whole volume of water in the container 1 is available for consumption. When faucet 9 is opened to take safe clean drinking water from the container 1 into the drinking jar 10 the valve 8 remains open and valves 5, 11 and 14 closed. The cycle in which safe drinking water is available from the fountain for consumption is completed when small part of clean water, between 0.1 and 2 L, remains in the water container 1. This is detected by optical or conductometric probe or other means known to one skilled in the art.

Cycle of cleaning of device commences when small part of clean water, between 0.1 and 2 L, remains in the water container 1. Valves 8 and 11 remain closed. The polarity of electrodes in electrolytic cell 6 is reversed by electric power supply 13. Valve 14 opens and clean water from container 1 flows through electrolytic cell 6 and settler 7 into the waste-water vessel 15. During operation valve 14 can be opened for short time intervals. The current of flowing water washes particles and debris electrodeposited on electrodes and particles collected in settler 7. After waste water vessel 15 is filled, as detected by optical or conductometric probe or other means known to one skilled in the art, the waste water is discharged. The cycle of cleaning of fountain is completed when all water from the container 1 flowed into the waste water vessel 15. This marks the end of the batch and new cycle of water cleaning commences.

Examples of removal of pollutants from drinking water with water fountain according to invention

In stationary and mobile embodiment of the water fountain is for given volumes of working vessel from 1 to 10 L and container from 10 to 50 L the required water cleaning time determined and up-loaded into the operational software system of the device for expected concentration of pollutant and mixtures of thereof in the source water. Figure 3 presents dynamics of removal of herbicide atrazine during the water cleaning cycle, and Figure 4 removal of desethyl-atrazine. Atrazine and desethly-atrazine are well known pollutants present in drinking water sourced from groundwater in areas with intensive farming activities. Figure 5 depicts decrease of concentration of ethylenediamine tetraacetate (EDTA) in during drinking water treatment in the fountain according to invention. Sources of EDTA in drinking waters are mainly waste industrial detergents.

DESCRIPTION OF DRAWINGS

Figure 1

Presentation of stationary embodiment of water fountain for preparation of safe drinking water. Presentation is symbolic and does not represent limitation to embodiments of the device.

Figure 2

Presentation of mobile embodiment of water fountain for preparation of safe drinking water. Presentation is symbolic and does not represent limitation to embodiments of the device.

Figure 3 Decrease of concentration of atrazine in water in the container of the water fountain during the water cleaning cycle. The active surface area of boron doped anode was 200 m², potential between electrodes was 10 V, average current 1.35 A and current density 6.7 mA cm^"2.

Figure 4

Decrease of concentration of desethly-atrazine in water in the container of the water fountain during the water cleaning cycle. The active surface area of boron doped anode was 200 m², potential between electrodes was 14 V, average current 2.39 A and current density 11.9 mA cm^"2.

Figure 5

Decrease of concentration of ethylenediamine tetraacetate (EDTA in water in the container of the water fountain during the water cleaning cycle. The active surface area of boron doped anode was 100 m², potential between electrodes was 9 V, average current 1.5 A and current density 15.0 mA cm^"2.

Claims

1. Fountain with safe drinking water for removal of pollutants from drinking water in water container characterized in that the water container (1) is with the system of pipes through electromagnetic valve (5) connected to electrolytic cell (6) and settler (7) and through another electromagnetic valve (8) to the faucet (9) from where safe drinking water is available for consumption (10), and where pump (12) circulates water through electrolytic cell (6), settler (7) and electromagnetic valve (11) back to container (1), and where water flow through the electrolytic cell (6) is repeated several times and precipitate is washed from settler (7) of mobile embodiment of fountain through valve (14) into the waste-water vessel (15), and where in stationary embodiment of fountain water circulates between electrolytic cell (6), settler (7) and working vessel (16) which enables constant filling of the container (1) with clean water from the working vessel (16).

2. Fountain according to claim 1 characterized in that the boron doped anode is preferably used in the electrolytic cell (6)

3. Fountain according to claims 1 and 2 characterized in that the water from container (1) circulates between electrolytic cell (6) and container (1) or working vessel (16) in a closed process loop and flows through electrolytic cell (6) in multiple times until pollutants are completely degraded and removed.

4. Fountain according to previous claims characterized in that for every expected water pollutant or mixture of thereof the water treatment time is pre-determined and up-loaded in the operational system of the fountain.

5. Fountain according to previous claims characterized in that in stationary embodiment of the fountain cleaning of water commences when volume of safe clean drinking water taken from water container (1) equals or exceeds the volume of the working vessel (16) and where volume of the working vessel (16) is several-times smaller compared to volume of the water container (1).

6. Fountain according to claim 5 characterized in that the water cleaning commences after the working vessel (16) is filled with source water and starts to circulate through the electrolytic cell (16) and settler (7) back to the working vessel (16) and that after water cleaning is completed the Water is transferred from the working vessel (16) into the container (1) from where sufficiently large quantities of safe clean drinking water is always available to consumer.

7. Fountain according to claims 5 and 6 characterized in that the fountain self-cleaning function is activated after determined number of transfers of clean water from the working vessel (16) into the container (1) after which the working vessel (16) is refilled from the water source and electric power supply (13) reverse the polarity in the electrolytic cell (6) and water flows from the working vessel (16) through electrolytic cell (6) and settler (7) in a drain or waste- water vessel (15) and in this way cleans the electrode surfaces and washes the settler (7).

8. Fountain according to claims 1, 2, 3, 4 and 5 characterized in that the mobile embodiment of the fountain operates in a batch mode in three sequential cycles where water cleaning cycle is followed by cycle of availability of safe drinking water from the fountain and this is followed by the cycle of cleaning of fountain, and where these cycles can not be interfered nor interrupted by the consumer.

9. Fountain according to claim 8 characterized in that the cycle of water cleaning commences with filling the container (1) and water is circulated between electrolytic cell (6), settler (7) and container (1) until pollutants are degraded and clean safe drinking water remains in the Container (1) from where it is available to consumer after the water cleaning cycle is completed.

10. Fountain according to claims 8 and 9 characterized in that during the cycle of availability of safe drinking water almost the whole volume of clean water in the container (1) is available for drinking and other uses except for the small part of the volume which is used for cleaning the fountain after the cycle of water availability is completed.

11. Fountain according to claims 8, 9 and 10 characterized in that cycle of cleaning the fountain commences after small part of the clean water remains in the container (1) and polarity of electrodes in the electrolytic cell (6) is reversed and water flows from the container (1) through the electrolytic cell (6) and settler (7) into the waste water vessel (15) and with this ends the cycle of cleaning of the fountain and new water cleaning cycle commences in the mobile embodiment of the fountain.