HK1165396B - A rainwater treatment unit - Google Patents

Description

Rainwater treatment device

Technical Field

The invention relates to the treatment of rainwater into drinking water.

Background

It has been the practice for many years to collect rainwater and process the collected rainwater and finally use the treated rainwater for household appliances such as dishwashers, washing machines, toilets and other appliances. This water is called greywater and its hygiene standard does not have to be the same as drinking water. Most domestic water is used as grey water, so most domestic water does not need to reach drinkable standards. Different methods and systems are known in the art for treating stormwater to grey water. Many of which are directed to household devices that collect rain water on the roof to provide grey water for use in the home. Since most households use quite a lot of grey water, methods and systems for treating rainwater to grey water are useful and have proven to be very effective in reducing the cost of supplying water to households.

In addition, many industrial processes require large amounts of water to perform many different processes. Sometimes water becomes a raw material or ingredient of a product, in which case the water quality must meet certain criteria. However, in most cases, water is used to assist in carrying out certain process steps, for example as a coolant in the drilling step or as a cleaning agent before the assembly or painting step, and grey water is used for this purpose. Many known systems are used to collect rainwater and process it into grey water for use in industrial processes.

It is clear that even though there are many known methods and systems for providing greywater for domestic and industrial use, these methods and systems are completely unsuitable for treating rainwater to potable water.

The treatment of rainwater to potable water is far more difficult than the treatment of rainwater to grey water because the rainwater must be thoroughly treated to remove all bacteria harmful to the drinker of the treated water. Sanitation is an important part of the process of treating rainwater into drinking water. Furthermore, it is also important to prevent the growth of bacteria in the water that has been treated and is ready for use. Methods and systems have been developed in recent years to treat rainwater into potable water.

One of these methods and systems is the applicant's own european patent publication number EP1652823, wherein the method and system is described for use in homes for providing drinking water to the homes. The method and system provide potable water to a home using a biocide which is ozone that is injected into the rain at predetermined time intervals. The system comprises a number of standard components which are found in any rainwater treatment system, such as drainage channels and even similar rainwater guide channels, and collecting devices connected to rainwater collection tanks, etc. In addition, the processing means of the system also comprise a series of components, among which processing tanks, pumps, control devices and different valves and level switches. It can be seen from the patented disclosure of the system that a large number of components are installed and interconnected to implement the rainwater treatment system.

In addition to the above systems, there are other rainwater treatment systems for producing drinking water, many of which include a large number of separate components, so that the system is heavy and takes up a large amount of space after installation, and such a large number of components are distributed in different places of a living room, and must be installed separately in the whole living room and then connected to form the rainwater treatment system.

Therefore, in any case of installing the rainwater treatment system, a relatively large engineering project is involved, and it is conceivable that the involved steps are many. In fact, the system installation of the aforesaid patent extends from the living room to an outside room and also to an underground cabinet, where connections are required to be installed and also monitored regularly to ensure that the connections operate properly. Since the process of connecting all the components of the rainwater treatment system to each other is complicated, the installation work costs are high and time is also consumed. Furthermore, since the different components of the system need to be located in different parts of the dwelling, existing parts of the dwelling may either need to be temporarily removed and/or displaced for installation of the rainwater treatment system.

Furthermore, since the rainwater treatment systems of the known art are heavy, installation works can affect rooms and places in and around the living room. Thus, in addition to being costly and time consuming, the large construction can be a serious nuisance to the occupants of the living room during the installation process.

As briefly mentioned above, the connections between the various components of the stormwater treatment system may extend from the living room to an outside room to an underground storage tank. Thus, the connections between the components can be relatively lengthy and can be subject to external weather conditions and, from time to time, to damage. Therefore, such a system connection of the known art requires supervision and maintenance.

The bulky volume of existing storm water treatment systems has the disadvantage that some components are relatively far apart. For example, the treatment device in the rainwater treatment system may be disposed outdoors, and the treated water storage tank may be disposed underground. From the above patents, it is known that both the treatment device and the treated water storage tank require an ozone injector. The treatment device requires an ozone injector to disinfect rainwater to produce potable water, while the treated water storage tank requires an ozone injector to maintain the treated water at a sanitary standard suitable for drinking. Because the treatment device and treated water storage tank are located separate from each other, two separate ozone injectors are required, which in turn requires two ozone supplies, or one at the expense of a large number of pipes, to provide ozone to two different locations. In addition, other components of existing stormwater treatment systems also need to be duplicated within the system, increasing the cost of the stormwater treatment system. The multiplicity of parts also complicates existing storm water treatment systems too much. Due to this complexity, maintenance costs are increased and failure is more likely.

A more compact, simple, easily installed and easily maintained rainwater treatment system is a sought after goal.

There is also a problem with existing storm water treatment systems.

Many existing stormwater treatment systems include a treated water storage tank that functions to hold treated water until use by the user. Treated water is supplied from the treated water storage tank to a potable water supply network when required by a user. If the treated water remains stationary in the treated water storage tank for too long a period of time, the sanitation quality may become less than optimal. Therefore, it is important to use a control system to maintain the treated water at a sanitary level.

As described above, the treated water storage tank is provided therein with the ultraviolet lamp and/or the aeration device, which is disposed in the treated water storage tank, so that the treated water is kept clean and sanitary. However, if the treated water has been stored in the treated water tank for too long, the use of aeration devices and/or ultraviolet lamps in the treated water storage tank has been indicated to be unable to completely maintain water quality hygiene. Such solutions are not ideal when the treated water is left still too long, for example during holidays, because of the room or industrial facility being emptied, and the water quality is still poor even with the uv lamp and/or the aeration device.

Many rainwater treatment systems are installed for use in non-primary dwellings that are emptied for long periods of time, so that any treated water in the treated water storage tank becomes undrinkable due to standing too long, bacterial growth. If the entire tank of treated water in the treated water tank is standing still for a long period of time, the use of an aerator and/or ultraviolet lamp to clean the treated water according to a predetermined time interval is insufficient to inhibit bacterial growth.

It is an object of the present invention to provide a stormwater treatment apparatus and method that addresses at least some of the disadvantages described above.

Disclosure of Invention

The invention relates to a method for treating rainwater into drinking water, which comprises the following steps: storing the collected rainwater in a rainwater containing box; providing collected rainwater from a rainwater containing tank through an inlet of a rainwater treatment device; filling rainwater with gas; irradiating the aerated rainwater with Ultraviolet (UV) rays to completely sterilize the rainwater; storing the sterilized water in a treated water tank of a rainwater treatment device; the sterilized water is pumped out of the treated water tank through the outlet of the rainwater treatment unit.

The advantage of using a gas to aerate the filtered rainwater to partially disinfect the rainwater and then using ultraviolet radiation to irradiate the aerated rainwater to completely disinfect the rainwater is that the rainwater can be completely disinfected in two simple steps to meet the strict sanitary standard required by drinking water. The gas cleans rainwater, and the ultraviolet ray sterilizes aerated water. Since the method uses such simple but effective steps, the method can be easily applied to a rainwater treatment apparatus which is compact in structure, small in size, and easy to install. None of the above-mentioned disadvantages of the known systems appear in any rainwater treatment system applying the method according to the claims. The components of the rainwater treatment system do not need to be connected in a large quantity, and the rainwater treatment system does not need a large quantity of installation engineering because the simplified method can be accommodated in a single rainwater treatment device, the rainwater treatment device can be transported to a destination singly and only comprises a rainwater inlet and a drinking water supply outlet. Since all connections between components have been previously provided in such storm water treatment devices, the installation and maintenance costs are substantially reduced compared to prior known storm water treatment systems.

In a further embodiment, the step of aerating the filtered stormwater with a gas comprises aerating the stormwater with a biocide formed using ultraviolet lamps.

The advantage of using a bactericide formed using an ultraviolet lamp to aerate rainwater is that the ultraviolet light can be used to make the bactericide and also as an irradiator. Thus, using the same ultraviolet light for both separate tasks makes the rainwater treatment system more compact and less cumbersome to construct. The ultraviolet rays do not need to be repeated in the rainwater system, and the space occupied by the whole rainwater treatment device is reduced due to fewer required components. Since this method avoids duplication of parts in the rainwater treatment system, the cost of the rainwater treatment system as a whole may be reduced. The operating costs of the rainwater treatment system are lower than those of the conventionally known rainwater systems because only one ultraviolet lamp is required to irradiate and produce the bactericide.

In a further embodiment, the sterilant is ozone formed by circulating air or oxygen adjacent the ultraviolet lamp.

In a further embodiment, the step of irradiating the aerated rainwater comprises delivering the aerated rainwater adjacent to a quartz tube housing an ultraviolet lamp. Such a feature is particularly advantageous as it allows the production of a biocide in a rainwater treatment unit by very compact and fine components and as an irradiator.

In a further embodiment, the method of the present invention also includes the step of monitoring the amount of water in the rainwater tank, and adding water from an additional water supply to increase the amount of water in the rainwater tank when the amount of water in the rainwater tank falls through a predetermined value.

This step is advantageous for the implementation of the method according to the invention, since the rainwater treatment system will not lack water to be delivered to the rainwater treatment unit, since either the collected rainwater or the water supplied to the rainwater tank, either, will be used for supplying water to the rainwater treatment unit.

In a further embodiment, the method of the present invention also includes evaluating the condition of the disinfected water in the treated water tank and, upon assessing that the disinfected water is not ideal, pumping water from the rainwater tank to the rainwater treatment unit, intentionally overflowing the treated water tank to recirculate the non-ideal disinfected water back through at least a portion of the rainwater treatment unit.

This has the advantage that the quality of the treated water is maintained at a desired sanitary level by recirculating the treated water through the treatment process. The treated water never comes to rest in the treated water tank to a point where harmful bacteria can grow in the treated water. This method is also advantageous in that it allows the treated water to be maintained at a strict sanitation level and quality without the need for a separate aeration device and/or irradiator within the treated water storage tank. The same aerator and/or irradiator that was used to disinfect the water may also be used to maintain the treated water at a desired sanitary level. Reusing these components in the rainwater treatment apparatus avoids duplication of components, and therefore, the rainwater treatment apparatus of the present invention is reduced in cost as compared to known rainwater treatment systems that occupy a large space after being installed in large quantities, and can also be provided in a housing that is easy to install and relatively simple to maintain and compact.

In a further embodiment, the non-ideal sterilized water is recirculated through an overflow pipe connecting the treated water tank and returned to the rainwater tank.

In a further embodiment, the method of the present invention also includes the steps of evaluating the condition of the disinfected water in the treated water tank and, upon evaluating that the disinfected water is not ideal, pumping the water from the treated water tank and recirculating it in at least a portion of the storm water treatment facility. This also avoids wasting water, as water with less than optimal quality will flow back to the rainwater tank.

In a further embodiment, the undesired sterilized water is recirculated into the stormwater treatment device before the step of aerating the filtered stormwater.

In a further embodiment, the undesired disinfected water is recycled into the rainwater treatment unit before the step of irradiating the aerated rainwater.

The invention also relates to a rainwater treatment combination for making rainwater into drinking water, which comprises a rainwater containing tank and a rainwater treatment device, wherein the rainwater treatment device comprises an inlet connected with an inlet filter and is used for eliminating redundant particles in rainwater; also included is a breather connected to the inlet filter, wherein the breather receives filtered rainwater from the inlet filter and aerates the filtered water with a gas; the irradiation device is connected with the ventilation device and comprises an ultraviolet lamp source for irradiating the aerated water and comprehensively disinfecting the rainwater; also includes a treated water tank connected to the irradiator for storing the fully disinfected water; a supply pump in the treated water tank is also included for pumping the disinfected water through an outlet filter to a rainwater treatment outlet.

The rainwater treatment device can be provided by a small compact, easily installed single piece, thus eliminating the disadvantages of the large size and bulkiness of the rainwater treatment systems of the prior art. The rainwater treatment unit includes an inlet for receiving rainwater and an outlet for supplying drinking water from the rainwater treatment unit. Thus, the rainwater treatment of the present invention consists of only one unit, and all necessary connections between the various components, such as the aerator, the irradiator, the treated water storage tank and the supply pump, etc., are complete. Furthermore, in a further preferred embodiment, the rainwater treatment unit may also be provided with a flow meter, inlet and outlet particle filters, control valves, and a control unit, and all necessary connections are already present. For example, the control device preferably receives data from different components, such as a level member, a flow meter member, a pump, a pressure calculator, etc., in order to evaluate the overall operational status of the storm water treatment device and then react, such as opening or closing valves, or initiating the operation of a pump, etc.

In a further embodiment, the gas entraining the filtered stormwater includes a germicide formed by using a source of ultraviolet light.

Such a feature is particularly advantageous because the ultraviolet lamp can be used to form a germicide and can also be used as an irradiator. The uv lamp is not duplicated in the rainwater treatment apparatus and the costs associated therewith are reduced. In addition, the maintenance is not so frequent, and the operating cost of the rainwater treatment apparatus is also reduced. Most importantly, because of the avoidance of component duplication, the rainwater treatment apparatus can be of compact and compact design, can be installed at a point in a dwelling or industrial facility, and can significantly reduce installation costs and time relative to prior art rainwater treatment systems. Since the time required for installing the rainwater treatment system is greatly shortened, nuisance to any resident in a living room or user of industrial facilities is greatly reduced.

In a further embodiment, the sterilant is ozone formed by circulating air or oxygen adjacent to the ultraviolet light source.

In a further embodiment, the source of ultraviolet light is housed within a quartz tube so that the gas-entrained water flows adjacent the quartz tube and is disinfected throughout by the irradiator.

In a further embodiment, the rainwater treatment assembly also includes a monitoring element for monitoring the level of water in the rainwater tank and an additional water supply valve operable to add additional water from the additional water supply to the rainwater tank to increase the volume of water.

In a further embodiment, the rainwater treatment assembly also includes an overflow conduit connected to the treated water tank, also connected to the additional water supply via an additional water supply valve.

In a further embodiment, the rainwater treatment assembly also includes a control assembly for assessing the health of the disinfected water in the treated water tank, and a rainwater supply pump for pumping water from the rainwater tank to the rainwater treatment unit, thereby deliberately overflowing the treated water tank to recirculate the water in the treated water tank back through at least a portion of the rainwater treatment unit.

This is a particularly simple but effective way to ensure that the treated water stored in the treated water tank does not stand still and does not flow, but instead can be recirculated throughout the stormwater treatment system. The treated water tank does not require additional aeration or irradiation and avoids duplication of parts. Thus, the associated financial expenditure involved in purchasing, installing, maintaining and operating the storm water treatment system is saved.

In a further embodiment, the rainwater treatment assembly also includes an overflow conduit extending from the treated water tank to the rainwater holding tank. This is a simple way of pumping disinfected water from the treated water tank back into the stormwater treatment system for recirculation. This requires only a small amount of additional plumbing, and keeps the rainwater treatment unit compact, small and easy to install.

In a further embodiment, the rainwater treatment assembly also includes a control assembly for assessing the sanitation of the disinfected water in the treated water tank and a recirculation pump for recirculating the disinfected water in at least a portion of the rainwater treatment apparatus.

In a further embodiment, a recirculation pump supplies disinfected water from a treated water tank to the aerator.

In a further embodiment, a recirculation pump supplies sterilized water from the treated water tank to the irradiator.

Depending on the time the treated water is stationary in the treated water tank or simply by pumping the treated water to the irradiator, the uv lamps clean the water. Passing the treated water through only the irradiators for cleaning purposes reduces the operating cost of the stormwater treatment system compared to other embodiments where the treated water is recirculated throughout the system.

Drawings

The invention will be more clearly understood from the following description of some specific embodiments thereof, given by way of example only, with reference to the accompanying drawings.

Fig. 1 is a diagrammatic side view of a stormwater treatment device according to the invention.

Fig. 2 is a diagrammatic plan view of the storm water treatment unit of fig. 1.

Fig. 3 is a diagrammatic front view of an irradiator for use in the stormwater treatment device of fig. 1.

Detailed Description

As shown in fig. 1 and 2, a stormwater treatment device is provided and is generally indicated by the reference numeral 100. Rainwater treatment apparatus 100 includes an inlet 102 and an outlet 104.

The rainwater is collected by a conventional method using a drain channel, a pipe, etc., and then sent to a rainwater tank 140. Such a system can be found in the granted european patent owned by the applicant under the grant EP1652823B 1. Rainwater is preferably supplied from the rainwater tank to the rainwater treatment apparatus 100 by a pump (not shown). Rainwater enters rainwater treatment apparatus 100 through inlet 102. An inlet valve 126 is provided to facilitate servicing of the rainwater treatment apparatus 100. A flow meter 128 is provided to ensure that the pump (not shown) is able to achieve the optimum flow rate. A particle filter 106 is used to remove excess particles from the rainwater. The size of the filter is preferably 5 μm or less. The filtered rainwater then enters an aerator, which in this embodiment is a venturi injector 108. Alternatively still, the venting means may be an air syringe pump or an air intake valve. The venturi injector 108 entrains filtered rainwater with a gas. The gas enters the venturi injector 108 through a gas inlet 109. In a preferred embodiment, the gas comprises ozone, but it will be appreciated that other gases, such as air, may be used to aerate the filtered stormwater. The aerated and filtered water then enters an irradiator 110. In this embodiment, the gas inlet is connected to the irradiator 110, but it will be appreciated that one end of the gas inlet may be open to allow air to be drawn into the venturi injector 108.

In a further embodiment, filtered rain water may enter an irradiator 110. The irradiated water then enters the aeration device, which in this embodiment is a venturi injector 108. The venturi injector 108 entrains filtered rainwater with a gas. The gas enters the venturi injector 108 through a gas inlet 109. In a preferred embodiment, the gas comprises ozone, but it will be appreciated that other gases, such as air or oxygen, may be used to aerate the filtered stormwater. Alternatively still, the venting means may be an air syringe pump or an air intake valve. The aerated and irradiated water flows down treated water tank supply pipe 112 into treated water tank 114.

Referring now to FIG. 3, wherein like parts are designated by like reference numerals. The applicator 110 includes an ultraviolet lamp source 302 received within a quartz tube 304 received within a housing 306 of the applicator 110. A water inlet 308 is provided in the lower portion of the housing 306 of the applicator 110 and a water outlet 310 is provided in the upper portion of the housing 306 of the applicator 110. The water outlet 310 is positioned (extending to the back of the page) at a right angle to the water inlet 308. A gas inlet 312 is provided below the housing 306 of the applicator 110 and a gas outlet 314 is provided above the housing 306 of the applicator 110. The uv lamp source 302 may be used to produce ozone by delivering air or oxygen into the gas inlet 312, spreading over the uv lamp source 302 in the quartz tube 304, and exiting through the gas outlet 314. The uv light source 302 functions to sterilise the gas-filled and filtered water entering via water inlet 308 by passing it between the outer envelope 306 and the quartz tube 304 along the length of the applicator 110 and then exiting it through the water outlet 314. The quartz tube 304 is sealed so that all liquid passing through the applicator 110 cannot enter the interior of the quartz tube 304. An electrical connection 316 to the uv lamp source 302 is also shown.

By creating free radicals of oxygen in the air and combining these radicals with oxygen molecules in the air, the oxygen in the air is converted into ozone:

O₂+UV→2O

filtered rainwater is composed of ozone (O)₃) Air is added to locally disinfect the rain. The aerated and filtered, partially disinfected rainwater then enters the irradiator 110 and flows out of the quartz tube 304. The ultraviolet rays of the ultraviolet lamp source irradiate the aerated and filtered rainwater through the quartz tube 304. The irradiation procedure disinfects the aerated and filtered rainwater.

Reference is now additionally made to fig. 1 and 2. Treated water exits the radiator 110 and flows down a treated water tank supply pipe 112 into a treated water tank 114. The treated water remains in the treated water tank 114 until a supply of potable water (not shown) is needed for extraction. A pump 116 pumps the treated water through an outlet filter supply line 118 to an outlet filter 120. The exit filter 120 preferably includes carbon, zeolites, or other like minerals as a catalyst to convert residual ozone to oxygen and/or to incorporate minerals into the water to improve the taste of the treated water. In addition, a colloidal silver, mineral or metal removal member may also be included as part of the outlet filter 120 to remove contaminants such as lead that may not have been removed during the process.

The treated water is sent to the drinking water supply through outlet 104. An isolation outlet valve 130 is disposed adjacent the outlet 104, and a pump control device 122 is disposed adjacent the isolation outlet valve 130. The pump control device 122 is used to control the pump 116 or to supply water through the outlet 104 according to a preset discharge pressure. For example, 2 bar is a typical output pressure. The means for controlling the speed of the pump 116 is located within the pump control device 122 or a controller 124.

The controller 124 is used to control the pump 116. The controller may also be used to monitor the level of rainwater in the rainwater tank 140 via a level indicator (not shown). The controller may top up the rainwater in the rainwater tank 140 from an external water supply, such as a main throat water supply. A main throat supply inlet 132 is connected to a conventional main throat supply. If the controller 124 detects that the amount of rain drops through a predetermined threshold, a controller activates the main throat supply valve 136 to allow water to flow from the main throat supply into the rain water tank 140. In a preferred embodiment, a filter 134 is disposed between the main throat supply inlet 132 and the main throat supply valve 136. Therefore, the rainwater tank 140 always has a reasonable amount of water supplied to the rainwater treatment apparatus 100.

In a preferred embodiment, water supplied from the main throat is added to the rain water tank 140 by supplying water from the rain water treatment device 100 through an overflow pipe 138 back to the rain water tank 140. An opening (not shown) in the treated water tank 114 leads to an overflow conduit 138.

In addition, the controller 124 may also monitor the amount and/or quality of treated water in the treated water tank 114. If the quality of the treated water drops through an acceptable level and becomes poor or undesirable, the controller may initiate the removal of poor quality treated water from the treated water tank 114. The suboptimal treated water is forced to flow through at least a portion of rainwater treatment apparatus 100. In a preferred embodiment, the suboptimal treated water flows into overflow conduit 138, which returns from rainwater treatment apparatus 100 to rainwater tank 140, back to rainwater tank 140. Therefore, pumping water into the rainwater treatment apparatus 100 causes a deliberate overflow, thereby overflowing the treated water tank 114. The overflow water flows down the overflow conduit 138 and the freshly treated water replaces the still, less preferred treated water. Thus, the treated water can be more clean.

The controller activates and deactivates the inlet pump (not shown) and/or acts as the uv light source 302 of the ozone generator. The uv lamp source 302 may be used to produce ozone by delivering air or oxygen into the gas inlet 312, spreading over the uv lamp source 302 within the quartz tube 304, and exiting through the gas outlet 314.

It is contemplated that in further embodiments, the main throat supply valve 136 may be used to close off the main throat supply inlet during the regeneration process.

The quality of treated water can be evaluated by the controller 124 by calculating the time for rainwater to enter the rainwater treatment apparatus 100. Flow meters (not shown) may optionally be provided on the inlet 102 and outlet 104 of the stormwater treatment device 100 before or after other components of the stormwater treatment device 100, such as the particulate filter 106, the venturi injector 108, the irradiator 110, the pump 116 and the outlet filter 120.

In a further embodiment (not shown), it is contemplated that the overflow conduit 138 may be connected to the particulate filter 106, the venturi injector 108, and/or the inlet of the irradiator 110. This embodiment does not require treated water of poor quality to flow through the entire rainwater treatment apparatus 100 again. This can reduce the operating cost of the rainwater treatment apparatus 100.

The words "comprise" or variations thereof in this specification are to be understood as being fully interchangeable and are to be given the broadest interpretation.

The invention is not limited to the foregoing embodiments, but may be varied in construction and detail within the scope of the appended claims.

Claims (17)

1. A method of treating stormwater for the production of potable water, comprising the steps of:

storing the collected rainwater in a rainwater containing box;

supplying the collected rainwater from the rainwater tank through an inlet of a rainwater treatment device;

irradiating rainwater with an Ultraviolet (UV) lamp;

adding gas into the irradiated rainwater to comprehensively disinfect the rainwater; storing the fully disinfected rainwater in a treated water tank of the rainwater treatment device;

pumping disinfected rainwater out of the treated water tank through an outlet of the rainwater treatment unit;

the method is characterized in that: the rainwater treatment method further comprises the following steps:

evaluating a state of disinfected rainwater in the treated water tank; and

when the disinfected rainwater is assessed to be at a sanitary level which does not meet the criteria, water is pumped from the rainwater tank to the rainwater treatment device, the treated water tank is deliberately overflowed, and the disinfected rainwater whose sanitary level does not meet the criteria is recirculated in at least a part of the rainwater treatment device.

2. A rainwater treatment method according to claim 1, characterised in that: the step of aerating the irradiated rainwater with a gas includes aerating the rainwater with a bactericide formed using an ultraviolet lamp.

3. A rainwater treatment method according to claim 2, characterised in that: the sterilant is ozone formed by the adjacent circulation of air or oxygen to the uv lamp.

4. A method of stormwater treatment as claimed in any preceding claim, wherein: the step of irradiating the rainwater includes transferring the rainwater adjacent a quartz tube housing the ultraviolet lamp.

5. A rainwater treatment method according to claim 1, characterised in that: it also includes the following steps:

monitoring the water quantity in the rainwater containing tank; and

when the amount of water in the rainwater containing tank falls through a preset value, the amount of water in the rainwater containing tank is increased by adding water from an additional water supply.

6. A rainwater treatment method according to claim 1, characterised in that: disinfected rainwater whose sanitary level does not meet the criteria of the assessment is returned to the rainwater tank through an overflow pipe connecting the treated water tank for recirculation.

7. A rainwater treatment method according to claim 1, characterised in that: disinfected rainwater, the hygiene level of which does not meet the requirements of the assessment criteria, is recirculated to the rainwater treatment unit before the step of aerating the irradiated rainwater.

8. A rainwater treatment method according to claim 1, characterised in that: disinfected rainwater, which does not meet the criteria for the hygiene level, is recirculated to the rainwater treatment unit before the step of irradiating the rainwater.

9. A rainwater treatment assembly for producing rainwater as potable water, the assembly comprising a rainwater tank and a rainwater treatment unit, wherein the rainwater treatment unit comprises:

an inlet connected to an inlet filter for removing any excess particles from the rainwater;

an irradiator connected to the inlet filter, the irradiator including an ultraviolet lamp source for irradiating rainwater; a breather connected to the irradiator, the breather receiving the irradiated rainwater from the irradiator and aerating the irradiated rainwater with a gas to completely disinfect the rainwater;

a treated water tank connected to the aeration device for storing the fully disinfected rainwater;

a supply pump in the treated water tank for pumping the disinfected rainwater through an outlet filter to an outlet of the rainwater treatment device;

the rainwater treatment combination is characterized in that: the rainwater treatment assembly further includes a control assembly for evaluating the health of disinfected rainwater in the treated water tank and a rainwater supply pump for pumping water from the rainwater containing tank to the rainwater treatment unit to cause deliberate overflow of the treated water tank and recirculation of water from the treated water tank back to at least a portion of the rainwater treatment unit.

10. A stormwater treatment combination as claimed in claim 9, wherein: the gas for aerating the irradiated stormwater includes a germicide formed using an ultraviolet light source.

11. A stormwater treatment combination as claimed in claim 10, wherein: the sterilant is ozone formed by the adjacent circulation of air or oxygen gas to the uv light source.

12. A stormwater treatment combination as claimed in claim 11, wherein: the ultraviolet lamp source is housed in a quartz tube so that rainwater flows adjacent to the quartz tube and is irradiated by the irradiator.

13. A stormwater treatment combination as claimed in any one of claims 9 to 12, wherein: the combination also includes a monitoring element for monitoring the level of water in the rainwater tank and an additional water supply valve which can be opened to allow an additional supply of water to be added to the rainwater tank to increase the amount of water.

14. A stormwater treatment combination as claimed in claim 13, wherein: the combination also includes an overflow conduit connected to the treated water tank and also connected to an additional water supply via an additional water supply valve.

15. A stormwater treatment combination as claimed in claim 9, wherein: the combination also includes an overflow conduit extending from the treated water tank to the rainwater tank.

16. A stormwater treatment combination as claimed in claim 9, wherein: the rainwater treatment assembly further includes an overflow conduit extending from the treated water tank to the inlet of the aeration device.

17. A stormwater treatment combination as claimed in claim 9, wherein: the rainwater treatment assembly further includes an overflow conduit extending from the treated water tank to the inlet of the irradiator.