WO2010092600A1

WO2010092600A1 - Water purification by ozone

Info

Publication number: WO2010092600A1
Application number: PCT/IS2010/000004
Authority: WO
Inventors: Arni Bergmann Petursson
Original assignee: Raf Ehf.
Priority date: 2009-02-13
Filing date: 2010-02-15
Publication date: 2010-08-19

Abstract

This invention relates to water purification systems using ozone. More specifically, it relates to an apparatus and method to treat waste water by injecting ozone into the apparatus of the present invention. The device of the present invention includes a purification tank, which can be compartmentalised where ozone is injected in one or more of the compartments. The method of present invention discloses treating waste water with sequential and stepwise injections of ozone to reduce or eliminate microorganisms in the liquid.

Description

WATER PURIFICATION BY OZONE

Field of the Invention

This invention relates to a method and apparatus of treating waste water using ozone. More specifically, it relates to an apparatus and method to purify water from sewage systems by injecting ozone into purification apparatus of the present invention.

Background of the Invention

Ozone has been widely used in water purification, sewage treatment and toxic waste treatment. When used in high doses, ozone will inactivate viruses, bacteria, moulds, and fungus as well as oxidising toxic substances. Furthermore, it is known that ozone is very effective at eliminating odours and killing bacteria and viruses.

US 2007248488 discloses a method for subjecting a microorganism to a combination treatment using ozone and UV light. It is claim that a synergistic effect is obtained for reducing concentration of microorganism, which are considered to be resistant to either ozone or UV light alone. It was shown that both Adenovirus and Naegleria fowleri were significantly more reduced when subjected with a combined and simultaneous treatment by ozone and UV light, than when subjected only to ozone or UV light.

US3680704 discloses an apparatus for secondary treatment of sewage effluent. The apparatus has an ozone contact chamber, which is connected to a tile field with a vent to the atmosphere at a point remote from the connection to the chamber. Ozone is produced by a geneator in compressed air and discharged into sewage effluent in the chamber. The ozone passes through the tile field and vent to the atmosphere to treat the sewage effluent in both the chamber and the tile field. The purpose of this device is to provide a secondary treatment apparatus of sewage effluent in order to eliminate offensive odors and increase the useful life of a sewage effluent tile field systems as well as increasing the capacity of a previously installed systems.

Summary of the Invention

It is the objective of the present invention to provide an apparatus and method for purifying waste water using ozone which is easy to maintain and preferably suitable to be buried in the ground. Preferably, the apparatus is able to transfer the liquid from one reaction chamber to another without needing a pump. The device of the present invention includes a purification tank, which comprises one or more serial compartments for purifying waste water where sequential and stepwise injections of ozone are used to reduce or eliminate microorganisms from the sewage. The apparatus is able to transfer the liquid from one serial compartment to another without pumping the liquid through the tank, even when blockage occurs in the course of transfer.

In a first aspect of the present invention a process is disclosed for reducing microorganisms in water such as waste water. The process comprises conducting water into a purification tank, where the tank comprises two or more adjacent compartments. The water is conducted into to the first compartment through an inlet positioned at the upper portion of the first compartment. The water is then transferred from the first compartment into to the second compartment through a first transfer pipe. The transfer pipe extends from the bottom portion of the first compartment and upwardly in the second compartment. Then ozone is injected into the tank from the bottom of the in least one of the compartments. The flow of water from the top of compartment against the injected ozone water and gas from the bottom of the compartment creates a circulation of the liquid in the compartment resulting in an increased contact time and contact surface. The outlet of the transfer pipe is positioned below the inlet into the first tank. The process is a sequential purification of water, such as sewage water using a multicompartment tank and ozone injection into each tank. The outlet of each consecutive transfer pipe is positioned each gradually below the inlet into the tank, from which the transfer pipe leads from creating a receding flow line. Therefore, for each compartment, water flows from that compartment into the next compartment automatically as the outlet of the transfer pipe is positioned below the corresponding outlet in the previous compartment. An airway or vent hole is provided for at the upper portion of each compartment, above the water surface, allowing un-reacted ozone to flow from one compartment to the next. Each air duct in the airway is positioned below the air duct from the previous compartment in order to create receding flow line of ozone from the first compartment to the last.

In a second aspect of the present invention an apparatus is disclosed for reducing microorganisms in water. The apparatus comprises a purification tank, further comprising two or more compartments, where the first compartment comprises an inlet on the upper portion of said first compartment and the second compartment is adjacent to the first compartment. A first transfer pipe extends from the bottom of the first compartment and upwardly into the second compartment, and at least on of the compartments comprises at least one ozone-injector for feeding ozone into the tank from the bottom of the compartment. The apparatus is characterised in that outlet the transfer pipe in each compartment is positioned below the inlet into the previous compartment. In a third aspect of the present invention a method is provided for reducing microorganisms in water by sequential purification. The method comprises conducting water into a purification tank, where the tank comprises at least two or more adjacent compartments. The water is conducted from one compartment to the next through transfer pipes and then ozone is injected into the tank from the bottom of the at least on of the compartments. The method is characterised by guiding the water through transfer pipes extending from the bottom of a previous compartment and upwardly into the next compartment. The method is further characterised by positioning the outlet of each consecutive transfer pipe below the inlet into the tank, from which the transfer pipe leads from, creating a receding flow line. In a fourth aspect of the present invention, a pumpless sewage treatment apparatus is provided. The apparatus comprises separating walls defining a plurality of serial treatment compartment where an ozone injector is located at the bottom. Each treatment compartment has an inlet at its upper portion and a outlet at its lower portion, as well as a vertical transfer pipe connecting the outlet of a treatment compartment to the inlet of a next serial compartment. The transfer pipe delivers waste water from one compartment upwardly to the next serial compartment. The inlet of a treatment compartment is preferably higher than the inlet of a next serial compartment.

In a fifth aspect of the present invention, a pumpless purification tank is provided.

Accordingly, a purification tank comprises a first treatment compartment which receives waste water from an inlet at its upper portion. It also comprises one or more serial treatment compartments which have an opening at its lower portion, through which waste water from previous treatment compartment can be received. The serial compartments additionally comprising a vertical transfer pipe having an intake-end and a release-end. The intake end is connected to the opening located at the lower portion of the same compartment. The release-end of the vertical transfer pipe is preferably higher than the release-end of the transfer pipe in the next serial compartment. Additionally, an ozone injector is located at the bottom of at least one of the treatment compartments.

In a sixth aspect of the present invention, a process for treating waste water with ozone is provided. The process comprises:

- conducting water into a first treatment compartment at a first height, - conducting the water from the first treatment compartment from the bottom upwardly via transfer pipe and discharging the water in the second treatment compartment at a second height,

- conducting the water from the second treatment compartment from the bottom upwardly via transfer pipe and discharging the water in the third treatment compartment at a third height,

wherein the first height is higher than the second height, and wherein the second height is higher than the third height,

- injecting ozone into the tank from the bottom of the said treatment compartments,

- transferring excess ozone from the first treatment compartment through a first vent hole to the second compartment,

- transferring excess ozone from the second treatment compartment through a second vent hole to the third compartment,

wherein the first vent hole is higher than the second vent hole.

Description of the Invention

In the present context the term "process for reducing microorganisms" refers to reducing, inactivating or eliminating viruses, bacteria, moulds, and fungus,

In the present context the term "purifying sewage using ozone" refers to reducing, inactivating or eliminating viruses, bacteria, moulds, and fungus as well as oxidising toxic substances and decreasing odours.

In the present context the term "pumptess" refers to the flow of liquid through the device of the present invention where water flows automatically through the multi-compartment tank, due to the construction of the tank, without pumping the water through the tank.

As defined herein, a compartment or a treatment compartment is a chamber where a liquid may be treated by ozone.

As defined herein, an air duct is a structure allowing ventilation which is useful for the release of excess ozone or other types of gas generated in the compartments. According to the present invention, an air duct may be in any forms, for example in the form of a duct or an opening for the air to flow through, also termed herein as vent hole.

As defined herein, water, liquid, waste water or sewage refers to a liquid which contains microorganisms for treatment. In the present context the term "ORP" is a definition for oxidation-reduction potential. ORP is measured in millivolts by ORP sensors or ORP measurement devices, measuring the dissolved oxygen. An ORP value represents the potency of a chemical substance to oxidize or reduce another chemical substance. Higher concentrations of contaminants (microorganisms or toxins) in the water result in less dissolved oxygen, resulting in a lower the ORP level. An increased ORP level, raises the potency of the water to destroy contaminants such as microorganisms or toxins. The ORP level in water can also be inicative of the level of bacterial activity in water, as there is a direct link between ORP level and bacterial count in water.

The following embodiments relate to the system, the method and the apparatus of the above mentioned aspects of the present invention.

In an embodiment of the present invention an ORP meter is positioned in the outlet from the last compartment of the purification tank for determining the amount of microorganisms after the purification.

In another embodiment of the present invention the outlet from the last compartment of the purification tank is an outlet pipe extending from the bottom of the last compartment and upwardly into a draining line and where the end of the outlet pipe is below the inlet into the last compartment. As defined herein, a draining line refers to piping leading away from the tank and into a stream of water or ocean. In an embodiment of the present invention vent holes above the water surface forming air duct connecting all compartments. In one embodiment, each vent hole is positioned lower than the vent hole in the previous compartment, whereas in another embodiment, all the vent holes are positioned in the same height (see figures). Furthermore, the last compartment comprises an air valve for exiting air from the tank.

In another embodiment of the present invention ozone is injected into the reaction compartments of the purification tank as ozone gas or as ozone saturated water.

In another embodiment of the present invention the process, method or apparatus is designed for reducing microorganisms in waste water such as sewage. In such a setup a septic tank may pre-treat the sewage before it enters into the purification tank. A pothole may be positioned between the septic tank and the purification tank. Settling or precipitation compartments can also be placed between, before or after ozone-reaction compartments providing a filter-free purification step.

In another embodiment of the present invention the flow of water from in inlet in each reaction compartment is guided into the compartment from the upper portion of compartment.

When the water is discharged to the bottom of the compartment it is met by the injected ozone from the bottom of the compartment providing an increased contact time and contact surface in each reaction compartment due to the circulation of the liquid in the compartment.

In another embodiment of the present invention the outlet from the last compartment of the purification tank comprises an ORP meter for determining the amount of microorganisms after the purification. In a specific embodiment of the ORP meter is positioned at the end of (near the outlet of) the outlet pipe.

In another embodiment of the present invention the outlet from each compartment of the purification tank is a transfer pipe extending from the bottom of a forgoing compartment and upwardly into the next compartment, where the outlet of the transfer pipe is below the inlet into the forgoing compartment with a height difference of preferably at least the radius of the transfer pipe, and most preferably equal to the diameter of the transfer pipe.

Furthermore, the outlet from the last compartment of the purification tank is an outlet pipe extending from the bottom of the last compartment and upwardly into a draining line, where the end of the outlet pipe is below the inlet into the last compartment.

In an embodiment of the present invention the process for killing bacteria and other microorganisms relates to the purification of sewage.

In an embodiment of the present invention one or more compartments can contain one or more layers of stones or gravel at the bottom of the compartment. The stone layers can serve as a filter, to filter out unwanted objects in the compartments and prevent them from entering the transfer pipe. The inlet of the transfer pipe can be positioned below the stone layers and then no solids should be transferred from one compartment to the next. The ozone injectors and the connection pipes connecting the injectors and the ozone generator can be designed as one pipe with outlets positioned in the pipe, as it extends along the bottom of the compartment. The injected ozone water/gas then migrates through the stone layer and into the compartment, meeting the flow of liquid from the transfer pipe.

One advantage of the present invention is providing the possibility of pump elimination. Many conventional treatment systems employ pump for the transferring of the waste water from one chamber to another. The presence of a pump may cause turbulence in the settling of microorganism or other substances in the liquid. Therefore, in may be in some instances desirable to avoid using a pump, for example, when costs and maintenances are taken into considerations.

Another advantage of the present invention is the prolonged reaction time of the ozone to the microorganism in the liquid. While such apparatus is generally designed to be buried in the ground, a compact but effective design is often desired. By using the counter flow system of ozone flow and liquid flow, as well as directing the liquid through a tortuous path, the purification efficiency is enhanced.

Detailed description of the Invention

The present invention will now be described with reference to the drawings and the specific embodiments in the drawings will be described using reference numbers to indicate the individual components of the invention.

Figure 1 is a schematic drawing of an embodiment of an ozone purification device according to the invention.

Figure 2 is a schematic drawing of the system of the present invention.

Figure 3 is a transactional view (perspective drawing) of an ozone purification tank according to the present invention.

Figure 4 shows a schematic drawing of an embodiment of the invention where one of the compartments is a precipitation compartment.

Figure 5 is a side view of the embodiment in Fig. 2, shown as a perspective drawing.

Figure 6 is a perspective drawing of an ozone purification device according to one embodiment of the present invention with a stone bottom layers. Figure 1 shows a schematic drawing of an ozone purification device for sequential purification of water. The device/apparatus comprises a multi-compartment purification tank 1, comprising (in this embodiment) four adjacent compartments 2a - 2d. The tank comprises an inlet 3 and an outlet 11, the inlet being in the first compartment 2a and the outlet in the last compartment 2d. The water is conducted into to the first compartment through the inlet 3 positioned on the upper portion of the first compartment. When water is being built up in the first compartment, the relatively cleaner water would enter the transfer pipe, termed also as the intake end, and gradually fill up the pipe due to atmospheric pressure. When it reaches to the top, also termed also as the release-end, of the transfer pipe, the water would be discharged downwardly into the next compartment. In this figure, the water is transferred from the first compartment into to the second compartment through a first transfer pipe 4a.

The discharged water from the pipe causes a swirl in the liquid already in the compartment. Ozone is injected into the tank from the bottom of the compartments by ozone injectors 5 creating flow of water against the injected ozone. The transfer pipe 4 extends from the bottom of the first compartment and upwardly into the second compartment. The outlet of the first transfer pipe 4a is positioned below the inlet 3 into the first tank (see broken line L2 for comparison). The ozone injectors 5 in each compartment are connected to a ozone generator 10 through a connection pipe 9 transporting ozone gas or ozone saturated water. The outlet of each consecutive transfer pipe 4a - 4c is positioned below the inlet into the tank, from which the transfer pipe leads from creating a receding flow line (see broken line L2 for comparison). An airway is positioned at the upper portion of each compartment consisting of an air duct 7 between each two adjacent compartment, where each air duct 7 in the airway is positioned below the air duct from the previous compartment in order to create receding flow line of ozone from the first compartment to the last (see broken line Ll for comparison).

Such arrangement of airway is termed herein as having a cascaded arrangement. This enables a cascaded delivery of ozone or other gas. When any of the transfer pipe is blocked, the liquid in the compartment may be delivered unidirectional into the next compartment. The outlet 11 from the last compartment of the purification tank is an outlet pipe extending from the bottom of the last compartment and upwardly, where the end of the outlet pipe is below the inlet into the last compartment (see broken line L2 for comparison). The outlet pipe further comprises an ORP meter/sensor 6 for monitoring the effectivity of the water purification device. Access openings 8 with a lid are provided at the top of each compartment for cleaning purposes or for pumping of precipitation from the compartments. The lid of the access opening in the last compartment further comprises an air valve 12 for exiting air from the system.

Figure 2 shows a schematic drawing of the ozone purification system of the present invention. Sewage enters the system through pipes 13 and is collected in a septic tank 14. Sewage water flows from the tanks through pipes to the purification tank 1 for sequential ozone purification as disclosed above. Wells 15, 16 are positioned in the pipeline for taking samples before and after the ozone purification process as well as for cleaning the pipe-lines and filtering out solid materials. The wells can also function to prevent vacuum in the system. The outlet from the last compartment of the purification tank is an outlet pipe extending from the bottom of the last compartment and upwardly into a draining line 17. The draining line is in this embodiment a piping structure leading away from the tank and into a stream of water or ocean.

Figure 3 is a transactionai view shown with a perspective drawing of an ozone purification tank according to one embodiment for purifying water from sewage systems. The tank has four compartments 2, an inlet 3 four intake of water into the First compartment and an outlet 11 for exiting water from the last compartment 2. Access openings 8 are positioned on top of each compartment 2 and on top of the access opening on the last compartment there is a air valve 12. The compartments 2 are connected by three transfer pipes 4.

Figure 4 shows a schematic drawing of an ozone purification device for sequential purification of water, where one of the compartments may be a precipitation or a settling compartment 2c. The precipitation compartment 2c has the function of filter-free sieving (filtration). The precipitate in the compartment can then be removed with a suction unit through the access opening 8 of the compartment. The reaction compartments 2a, 2b and 2d all have ozone injector 5 connected to an ozone generator 10, whereas the precipitation compartment 2c has not.

Figure 5 is a side view of the embodiment in Fig. 2, shown as a perspective drawing. The figure shows the position of the transfer pipes 4a - 4c and how the outlet of each consecutive transfer pipe is lower than the outlet of the previous pipe. (See line L2 for comparison)

Figure 6 shows a further embodiment which contains two layers of stones or gravel 18, 19 at the bottom of each compartment. The stone layers can serve as a filter, to filter out unwanted objects in the compartments and prevent them from entering the transfer pipe, as the inlet of the transfer pipe is positioned below the stone layers. In this embodiment, the ozone injectors 5 and the connection pipes 9 are shown and designed as the same component going into the tank from the top, penetrating the stone layers in each compartment. The injected ozone water/gas then migrates through the stone layer and into the compartment, meeting the flow of liquid from the transfer pipe.

Claims

1. Apparatus for reducing microorganisms in water, the apparatus comprising:

- a purification tank, said tank comprising two or more compartments, - the first compartment comprising an inlet on the upper portion of said first compartment,

- a second compartment adjacent to the first compartment

- a first transfer pipe extending from the bottom portion of the first compartment and upwardly into the second compartment, - at least one ozone-injector for feeding ozone into the tank from the bottom portion of the at least on of the compartments; characterised in that the outlet the transfer pipe in each compartment is positioned below the inlet of the previous compartment.

2. The apparatus according to claim 1 wherein an ORP meter for determining the amount of microorganisms after the purification is positioned at the outlet end of the apparatus.

3. The apparatus according to claim i, wherein the outlet from each compartment of the purification tank is a transfer pipe extending from the bottom portion of a forgoing compartment and upwardly into the next compartment, where the outlet of the transfer pipe is below the inlet into the forgoing compartment.

4. The apparatus according to claim 1, wherein walls separating each compartment have a vent hole.

5. The apparatus according to claim 1, wherein the vent hole of a forgoing compartment is higher than the vent hole of the next compartment, thereby causing a cascaded delivery of excess ozone or waste water into next serial treatment compartment.

6. The apparatus according to claim 1, wherein the apparatus is a part of a system to reduce microorganisms in sewage water.

7. The apparatus according to claim 1, wherein the last compartment comprises an air- valve. 010/000004

12

8. The apparatus according to claim 1, wherein a settling or precipitation compartment is placed between ozone-reaction compartments providing a filter-free purification step.

9. The apparatus according to claim 1, wherein the apparatus further comprises a filter unit at the bottom of at least one of the compartments.

10. The apparatus according to claim I₁ wherein each compartment has a closable access opening.

11. The apparatus according to claim 1, wherein the purification tank comprises at least 3 serial compartments.

12. A method for reducing microorganisms in water, the method comprising:

- conducting water into a purification tank, the tank comprising two or more adjacent compartments,

- conducting the water from one compartment to the next through transfer pipes,

- injecting ozone into the tank from the bottom portion of the at least on of the compartments;

characterised in

- creating a receding flow of water from one compartment to the next using gu transfer pipes extending from the bottom portion of a previous compartment and upwardly into the next compartment, wherein the outlet of each consecutive transfer pipe is positioned below the inlet into the tank, from which the transfer pipe leads from,

- wherein the flow of water from the upper portion of the compartment meets the injected ozone from the bottom portion of the compartment creating circulation of the water in the compartment and providing increased contact time for the ozone and the microorganisms.

13. The method according to claim 12 wherein an ORP measurement is performed in the outlet from the last compartment of the purification tank for determining the amount of microorganisms after the purification.

14. The method according to claim 12, wherein air or un-reacted ozone is conducted through vent holes connecting the compartments, being positioned above the water surface.

15. The method according to claim 12, wherein the method Is to reduce microorganisms in sewage water.

16. The method according to claim 12, wherein air from the purification is exited through an air valve in the last compartment of the tank.

17. The method according to claim 12, wherein a filter-free purification step is added to the method using a settling or precipitation compartment.

18. A process for reducing microorganisms in water, the process comprising :

- conducting water to a purification tank, said tank comprising two or more compartments,

- conducting the water into to the first compartment through an inlet at the upper portion of said first compartment, - transferring the water from the first compartment into to the second compartment through a first transfer pipe,

- injecting ozone into the tank from the bottom of the at least on of the compartments; characterised in that the transfer pipe extends from the bottom of the first compartment and upwardly into the second compartment, where the outlet of the transfer pipe is below the inlet into the first tank.

19. The process according to claim 18, wherein a septic tank is positioned before the purification tank.

20. The process according to claim 18, wherein a pothole is positioned between the septic tank and the purification tank.