US20100300544A1

US20100300544A1 - Rainwater recovery and treatment system

Info

Publication number: US20100300544A1
Application number: US12/477,015
Authority: US
Inventors: Timothy Joseph Baldwin; Kevin C. Eberle
Original assignee: Waterdogs Water Recovery LLC
Current assignee: Waterdogs Water Recovery LLC
Priority date: 2009-06-02
Filing date: 2009-06-02
Publication date: 2010-12-02

Abstract

Embodiments of the invention relate to systems and methods for the harvesting and treatment of rainwater for secondary use within buildings. Rainwater is harvested utilizing a rainwater capturing device and stored in a cistern prior to treatment until a demand for secondary use is made. The rainwater may be combined with reclaimed water from a water treatment plant. Once a demand for secondary use is made, the water is subjected to treatment as it travels to the point of use. Treatment includes neutralizing the pH of the rainwater, filtering the rainwater to remove particulate matter, irradiating the rainwater with ultraviolet light, and introducing a chlorine solution into the rainwater.

Description

FIELD

In general, embodiments of the invention relate to systems and methods for the harvesting and treatment of rainwater.

BACKGROUND

In today's world, water is voraciously consumed with little thought to the devastating effects that result from such uncontrolled consumption. The excessive and inefficient use of water by the world's population does not reflect an adequate understanding of the fact that the amount of fresh water in this world is limited. No longer problems exclusively belonging to third world countries, lack of water supply and flawed water infrastructure plague communities across the globe. It is anticipated that these challenges will only become worse as the world's population grows. Increased demand for water places additional stress on water supplies and distribution systems, threatening both human health and the environment. Indeed, lower water levels due to depleting reservoirs and groundwater can contribute to higher concentrations of natural or human pollutants. Furthermore, it takes a considerable amount of energy to deliver and treat the water that we use everyday.
By using water more efficiently, individuals and communities can preserve water supplies for future generations, minimize the effects of droughts, save money, and protect the environment. Indeed, reducing the consumption of water from public water supplies reduces the energy required to supply and treat the water, which counters climate change and other threats to our environment. Moreover, consumers can save significant amounts of money that would otherwise be spent on water obtained from public water supplies. However, despite the fact that many are aware of the downfalls of excessive consumption of water and the benefits provided by adopting efficient behaviors with regard to water use, water conserving techniques are generally not implemented in favor of continuing to use outdated systems and methodologies that needlessly waste fresh water from our supplies and reservoirs. For example, substantial amounts of potable water are consumed in the course of uses that do not, in fact, require potable water, such as flushing toilets. In sum, the consumption of water from public supplies needs to be drastically reduced, and realistic and economical solutions that serve this goal are required.

SUMMARY OF EMBODIMENTS OF THE INVENTION

Embodiments of the present invention relate to systems and methods for the harvesting and treatment of rainwater for secondary use. More particularly some embodiments of the invention provide a rainwater recovery and treatment system for secondary use comprising the following elements: a rainwater capturing device configured to capture falling rainwater, a pump station configured to receive the rainwater captured by the rainwater capturing device, a pH adjustment device configured to neutralize the pH of the rainwater, a filtration device configured to remove particulate matter from the rainwater, an ultraviolet disinfection device configured to irradiate the rainwater with ultraviolet light, and a chemical disinfection device configured to introduce chlorine into the rainwater.
The system may further comprise a rainwater storage device configured to store water and connected via a first conduit to the rainwater capturing device and via a second conduit to the pump station, wherein the rainwater captured by the rainwater capturing device flows through the first conduit into the rainwater storage device for storage and then flows through the second conduit into the pump station.
In some embodiments, the rainwater storage device is a cistern. According to one embodiment, the rainwater storage device is buried underground and comprises an impervious liner and stone fill. In one embodiment, the rainwater storage device is integrated into another water management system. With regard to the rainwater capturing device, it may be located on the roof of a building, or even comprise the roof of a building.
In some embodiments, the pump station is configured to utilize at least one level measuring device and a pump station control system to maintain the level of water held by the pump station within a particular range of levels.
The system may also include a pressurizing device configured to pressurize the rainwater prior to it passing through any of the pH adjustment device, the filtration device, the ultraviolet disinfection device, or the chemical disinfection device. The pressurizing device may comprise a hydro-pneumatic tank. The pH adjustment device may comprise at least one calcite filter. In some embodiments, the filtration device comprises at least one of the following: a disc filter, a cartridge filter, or a membrane filter. According to some embodiments, the chemical disinfection device comprises an on-site hypochlorite generating system or a tablet chlorinator.
The system may further comprise a chlorine sensor configured to measure the level of chlorine present in water and a master control system configured to receive transmissions from the chlorine sensor and interface with the chemical disinfection device, wherein the master control system is configured to cause the chemical disinfection device to adjust the amount of chlorine introduced into the water based on a transmission from the chlorine sensor.
According to other embodiments of the invention, a water recovery and treatment system for secondary use is provided, the system comprising a rainwater storage device configured to store rainwater, a pump station configured to receive rainwater from the rainwater storage device and reclaimed water, wherein the pump station is further configured to receive reclaimed water only in the event the pump station is unsuccessful in receiving a predetermined volume of rainwater from the rainwater storage device, and a water treatment system.
In some embodiments, the rainwater storage device is a cistern. According to some embodiments, the rainwater storage device is buried underground and is comprised of an impervious liner and stone fill. The rainwater storage device may be integrated into another water management system.
According to some embodiments, the pump station is configured to utilize a level measuring device and a pump station control system to maintain the level of water held by the pump station within a particular range of levels. In some embodiments, the pump station control system is configured to receive signals from the level measuring device that cause the pump station to receive rainwater from the rainwater storage device. Indeed, the pump station control system may be configured to cause the pump station to receive reclaimed water in the event the pump station is unsuccessful in obtaining a predetermined volume of rainwater from the rainwater storage device.
In some embodiments, the water treatment system comprises a pH adjustment device configured to neutralize the pH of water, a filtration device configured to remove particulate matter from water, an ultraviolet disinfection device configured to irradiate water with ultraviolet light, and a chemical disinfection device configured to introduce a chlorine into water. The system may further include a pressurizing device configured to pressurize water prior to it passing through any of the pH adjustment device, the filtration device, the ultraviolet disinfection device, or the chemical disinfection device. In some embodiments, the pressurizing device comprises at least one hydro-pneumatic pump. In some embodiments, the pH adjustment device comprises at least one calcite filter. According to some embodiments, the filtration device comprises at least one of the following: a disc filter, a cartridge filter, or a membrane filter. In some embodiments, the chemical disinfection device comprises an on-site hypochlorite generating system or a tablet chlorinator.
The system may further comprise a chlorine sensor configured to measure the level of chlorine present in water and a master control system configured to receive signals from the chlorine sensor and interface with the chemical disinfection device, wherein the master control system is configured to cause the chemical disinfection device to adjust the amount of chlorine introduced into the water based on a signal from the chlorine sensor.
According to other embodiments of the present invention, a method of recovering and treating rainwater for secondary use within a building is provided, the method comprising: capturing rainwater utilizing a rainwater capturing device, storing the rainwater in a rainwater storage device, neutralizing the pH of the rainwater, filtering the rainwater to remove particulate matter, irradiating the rainwater with ultraviolet light, and introducing a chlorine solution into the rainwater. The method may further include obtaining reclaimed water and combining the reclaimed water with the rainwater. In some embodiments, the reclaimed water is obtained from a water treatment plant. According to some embodiments, the reclaimed water is combined with the rainwater prior to said neutralizing, filtering, irradiating, and introducing steps. In some embodiments, the reclaimed water and the rainwater are combined in a pump station.
According to some embodiments, the rainwater capturing device comprises a roof of a building. With regard to the rainwater storage device, it may be buried underground, and comprised of an impervious liner and stone fill.
Certain embodiments of the present invention provide a product comprising water produced by a method comprising: capturing rainwater utilizing a rainwater capturing device, storing the rainwater in a rainwater storage device, neutralizing the pH of the rainwater, filtering the rainwater to remove particulate matter, irradiating the rainwater with ultraviolet light, and introducing a chlorine solution into the rainwater.
Still other embodiments of the present invention provide a system for the supply of water for secondary use, the system comprising: a building comprising a rainwater capturing device and a rainwater treatment unit, a water storage device comprising a cistern and a pump station, wherein the water storage device is configured to receive rainwater from the rainwater capturing device and reclaimed water, combine the rainwater and the reclaimed water, and transfer the combined rainwater and reclaimed water to the building for treatment by the water treatment system. In some embodiments, the water treatment system comprises: a pH adjustment device configured to neutralize the pH of acidic water, a filtration device configured to remove particulate matter, an ultraviolet disinfection device configured to irradiate water with ultraviolet light, and a chemical disinfection device configured to introduce a chlorine solution into water.

BRIEF DESCRIPTION OF THE DRAWINGS

Having thus described embodiments of the invention in general terms, reference will now be made to the accompanying drawings:

FIG. 1 is a diagram illustrating a rainwater recovery system according to one embodiment of the present invention;

FIG. 2 is a diagram illustrating a rainwater treatment system according to one embodiment of the present invention;

FIG. 3 is a diagram illustrating a cistern system according to one embodiment of the present invention;

FIG. 4 is a flow chart illustrating an exemplary method of recovering and managing rainwater in anticipation of secondary use in buildings, according to one embodiment of the invention; and

FIG. 5 is a flow chart illustrating an exemplary method of treating rainwater for secondary use in buildings, according to one embodiment of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

As discussed above, there is a need to reduce the consumption of fresh water from public water supplies. To be certain, this goal may be achieved by an overall reduction in water use. On the other hand, and as reflected by the present invention, this goal may also be achieved without reducing water use, but by utilizing recovered rainwater or a combination of rainwater and treated reclaimed water as a substitute for water that would otherwise come from the public supplies. As used herein, the term “reclaimed water” means water treated to reuse/reclaimed water standards (i.e. reclaimed water from a wastewater treatment plant that produces effluent that may be classified as reclaimed or reuse water). The present invention reduces a building's consumption of water from public water supplies by eradicating the use of that water for secondary uses within the building, instead utilizing rainwater or a combination of rainwater and reclaimed water for such secondary uses. As used herein, the term “secondary use” means any use for which potable water is not required, such as toilet flushing, use in air conditioning systems, fire suppression etc. Therefore, according to some embodiments, once the invention is implemented, the water that runs in the sinks of the building is fresh water supplied by the city or other customary water source, while the water that runs in the toilets is rainwater or a combination of rainwater and reclaimed water that is treated and supplied by the systems of the present invention.
The present invention operates under the assumption that secondary uses do not require water having the highest level of purification, as is required for primary uses. By continually expending potable water for secondary uses, for example, in the process of flushing toilets, buildings and communities are wasting an opportunity to cut costs and decrease their carbon footprint. The present invention seeks to alter the status quo and capitalize on this opportunity by dividing the uses of water within a building into primary or secondary uses, and causing the supply of water of varying purification levels from distinct sources depending upon the use. Specifically, potable water from the building's traditional water source is supplied to the points of use corresponding to primary uses, while water from the recovery and treatment system of the present invention is supplied to the points of use corresponding to secondary use (i.e. toilets).
This bifurcation of the water infrastructure of a building advantageously allows the building to consume substantially less water from its conventional source, which is in many cases the public fresh water supply. Indeed, by eliminating a significant source of demand for water from public supplies (the demand for secondary uses), the present invention conserves potable water that would otherwise be needlessly consumed by secondary uses. This benefits the environment by preserving limited water resources and decreasing the amount of energy that must be expended to treat and deliver water from the public supply. Moreover, it reduces the financial expenses associated with the acquisition of water from the public supply.
With regard to how the present invention operates in practice, the present invention provides for the harvesting and storage of rainwater, the optional combination of this rainwater with reclaimed water, and the treatment of the combined water in anticipation of secondary use in a building. These processes and the systems utilized to effectuate these processes will be discussed in detail below. It should be noted that the use of rainwater is preferred to the use of reclaimed water, inasmuch as using rainwater is not only free, but also a more environmentally friendly practice. Indeed, reclaimed water is more environmentally friendly than fresh water because it is recycled, since it must be treated at a plant and delivered to the building, it has a number of the same energy costs as fresh water from public supplies. It should also be noted that the systems and methods of the present invention may be implemented on any scale, from single family houses to large commercial buildings to entire communities. The only requirement is that the plumbing of the house, building, community, etc. be configured such that points of use corresponding to secondary uses are connected directly or indirectly to the system of the present invention, rather than connected to the traditional water supply. Thus, when a demand for water is made for secondary use, the treated rainwater or the treated combination of rainwater and reclaimed water of the present invention is supplied, rather than the fresh water from the public water supply.
Embodiments of the present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all, embodiments of the invention are shown. Indeed, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.
FIG. 1 is a diagram that illustrates a rainwater recovery system 100 according to a preferred embodiment of the present invention. FIG. 2 is a diagram that illustrates a rainwater treatment system 200 according to a preferred embodiment of the present invention. Together, FIGS. 1 and 2 illustrate a rainwater recovery and treatment system in accordance with a preferred embodiment of the invention. The rainwater recovery system 100 and rainwater treatment system 200 are illustrated in separate figures for purposes of clarity and convenience only, and it should be understood that the subject matter presented in each figure may be combined to provide a complete rainwater recovery and treatment system according to some embodiments of the invention.
As shown in FIG. 1, at least one rainwater capturing device 110 is provided. In some embodiments, the rainwater capturing devices 110 is placed on or incorporated into the roof of a building in which the water treated by the rainwater treatment system 200 will be used. The roof itself may be the rainwater capturing device 110. In other embodiments, the rainwater capturing device 110 may be located on the roofs of other buildings and in other locations in addition to or instead of the roof of a building in which the water treated by the rainwater system 200 will be used. In different embodiments, the rainwater capturing device 110 is an open top tank, a sloped sheet made of metal, concrete or other material, a membrane or liner configured to collect rainwater, a gutter, or any combination of the foregoing. The rainwater capturing device 110, according to some embodiments, is configured such that rainwater captured thereby may be transferred to a rainwater storage device, such as the cistern 120 shown in FIG. 1, that is configured to store the rainwater until there is a demand for it. It should be understood that such a rainwater storage device is optional.
In some embodiments, and as illustrated in FIG. 1, the cistern 120 is located in a remote location in relation to the rainwater capturing device 110. In such embodiments, storage conduits 112 such as downspouts and pipes connect the rainwater capturing device 110 and the cistern 120 such that the rainwater captured by the rainwater capturing device 110 may travel to the cistern 120 through the storage conduits 112. In other embodiments, the cistern 120 may be directly attached to the rainwater capturing device 110. In still other embodiments, the cistern 120 and the rainwater capturing device 110 may be one and the same. Depending on the configuration of the rainwater capturing device 110 and the cistern 120, especially with regard to the elevation drop from the rainwater capturing device 110 to the cistern 120, a pressurizing device such as a pump may be provided to instigate the flow of rainwater from the rainwater capturing device 110 to the cistern 120. Alternatively, the rainwater capturing device 110 and the cistern 120 may be configured such that there is a sufficient elevation drop between them to allow hydrostatic pressure to cause the flow of rainwater from the rainwater capturing device 110 to the cistern 120. According to some embodiments of the present invention, the cistern 120 may be integrated into other water management systems separate from the rainwater recovery and treatment system that is the subject of embodiments of the present invention. For example, and as illustrated in FIG. 3, the cistern 120 may be integrated into a stormwater management system.
FIG. 3 provides a schematic drawing of an exemplary cistern 120 integrated with a stormwater management system according to some embodiments of the present invention. As shown in FIG. 3, concrete box culverts 310 are provided for detaining stormwater other than rainfall, for example, surface runoff. In some embodiments, the culverts 310 are buried beneath the ground and are encapsulated by a bed of washed stone fill 320. The empty volume within the bed of washed stone fill 320 (created by the space between stones) may be filled with the rainwater captured by the rainwater capturing device 110 such that the bed of washed stone fill 320 is the cistern 120 that stores the rainwater. An impervious liner 312 separates the bed of washed stone fill 320 from the surrounding ground to contain the rainwater and prevent exposure of the rainwater to contaminants that could be introduced by the surrounding ground. According to some embodiments, attached to the bed of washed stone fill 320 are two conduits—an incoming conduit 322 for carrying rainwater captured by the rainwater capturing apparatus 110 into the bed of washed stone fill 320 and an outgoing conduit 324 for carrying the rainwater stored in the bed of washed stone fill 320 out of the bed of washed stone fill 320 in anticipation of treatment and, ultimately, use. In some embodiments, the incoming conduit 322 and the outgoing conduit 324 are one and the same.
The foregoing example of a cistern 120 in accordance with some embodiments of the invention should not be construed to limit the type of cistern that may be utilized in embodiments of the present invention. Indeed, those skilled in the art will be capable of designing and implementing the cistern 120 in countless ways within the scope of the present invention, depending upon the particular environment in which the rainwater recovery and treatment system is being installed. For instance, the cistern 120 may take the form of an above-ground open top or closed top storage tank, a buried storage tank, or a lined reservoir or lake. The foregoing example was provided because it demonstrates one way in which the cistern 120 may be advantageously and seamlessly incorporated into a larger water management environment.
In the event a stormwater detention system and a rainwater recovery system are being constructed at the same time, by integrating the cistern 120 with stormwater storage devices such as the culverts 310, the work and expense associated with the construction of the stormwater and rainwater systems may be reduced or minimized. In that regard, in order to bury the culverts 310 under ground, a volume of earth much larger than the culverts 310 themselves must be excavated, and in some cases, removed and relocated to a remote location. In such instances, rather than hauling in compact fill to fill the excavated area surrounding the culverts 310 and constructing a separate cistern 120 for rainwater, it is advantageous to use the excavated area surrounding the culverts 310 as the cistern 120. Moreover, burying the cistern 120 underground is advantageous as it preserves space above ground and increases the elevation difference between the cistern 120 and the rainwater capturing device 110, which aids the travel of the rainwater from the rainwater capturing device 110 to the cistern 120. As discussed above, the cistern 120 may be created by utilizing an impervious liner 312 and washed stone fill of a minimum particulate size.
Referring again to FIG. 1, in some embodiments, a pump station 130 having a wet well therein is provided that is configured to receive rainwater from the cistern 120. The pump station 130 has a first incoming conduit 131 that is connected to the cistern 120, either directly or indirectly, and serves as a conduit for the rainwater arriving at the pump station 130 from the cistern 120. The pump station 130 may also have, according to some embodiments, a second incoming conduit 132 that serves as a conduit for reclaimed water arriving at the pump station 130 from a wastewater treatment plant 150. It should be understood that the second incoming conduit 132 bringing reclaimed water to the pump station 130 is optional, and in some embodiments the pump station 130 shall be configured such that the only water it receives is rainwater from the cistern 120. In some embodiments, the pump station 130 is configured to hold water that will be transferred to the rainwater treatment system 200 upon demand. Therefore, according to some embodiments, the pump station 130 is equipped with various pumps 133, level measuring devices 134, and a pump station control panel 135 that ensure that the wet well of the pump station 130 continually holds an adequate amount of water to meet the requirements at the point-of-use.
In some embodiments, the pump station control panel 135 is configured to receive indications from the level measuring devices 134 and operate the pumps 133 to pump water into the pump station from either the cistern 120 (through the first incoming conduit 131) or the wastewater treatment plant 150 (through the second incoming conduit 132). Alternatively, in other embodiments, the cistern 120 and the pump station 130 may be configured such that there is a sufficient elevation drop between them to allow hydrostatic pressure to cause the flow of stored rainwater from the cistern 120 to the wet well of the pump station 130. Indeed, the wastewater treatment plant 150 and the pump station 130 may be likewise configured such that the reclaimed water flows to the wet well of the pump station 130 due to hydrostatic pressure, rather than any pumping mechanism.
According to some embodiments, the pump station 130 is configured to prefer holding rainwater from the cistern 120 rather than reclaimed water from the wastewater treatment plant 150. In such embodiments, the pump station control panel 135 may be configured to either operate the pumps 133 to pump rainwater from the cistern 120 or allow the rainwater to flow in through the first incoming conduit 131 due to gravity, whenever the level measuring devices 134 indicate that the level of water within the pump station 130 has reached a predetermined minimum amount. Indeed, the pump station control panel 135 may be configured to operate the pumps 133 or otherwise allow the flow of rainwater through the first incoming conduit 131 until the level measuring devices 134 indicate that the level of water within the pump station 130 has reached a predetermined desired amount, at which point the pumping will cease. It should be understood that all processes of the pump station 130 may be controlled by one or more computer programs of the pump station control panel 135, as is appreciated by those skilled in the art. In such embodiments, the pump station 130 may be configured to only allow the rainwater from the cistern 120 to flow into the wet well of the pump station 130 until the water level in the wet well reaches a predetermined maximum amount.
In some embodiments, the pump station control panel 135 is further configured to allow reclaimed water to enter the pump station 130 only when the pump station 130 is unsuccessful in replenishing its storage of water to the desired level with rainwater alone, either by operating the pumps 133 or by opening the interface of the wet well and the first incoming conduit 131 to allow the reclaimed water to flow in due to gravity. Therefore, according to some embodiments, the pump station 130 will preferentially hold rainwater from the cistern 120, but may hold reclaimed water in the event the cistern 120 is low or dry, for example, during periods of little to no rainfall.
As described above, according to some embodiments, the pump station 130 is configured to maintain water (either rainwater, reclaimed water, or a combination of the two) inside the wet well of the pump station 130 within a specific level range or, alternatively, at a specific level until a demand for the water is made. In embodiments where the water is to be maintained at a specific level, the predetermined minimum level and the predetermined desired level are the same. It is necessary that the pump station 130 maintain water at or above a particular level so that there is enough water in the pump station 130 to be transferred to the rainwater treatment system 200 on the demand of users within the building. According to a preferred embodiment, the pump station 130 has a first outgoing conduit 136 that connects the pump station 130 to the rainwater treatment system 200 and carries water from the wet well of the pump station 130 to the rainwater treatment system 200 on demand from the point-of-use.
In some embodiments, the pump station also has a second outgoing conduit 137 that carries water (directly or through a series of conduits) from the pump station 130 to a particular point-of-use, without passing through any treatment system or undergoing any treatment process in between. Therefore, unlike secondary uses within a building, there may be some uses that do not require treatment of the water at all prior to use. For example, irrigation and agricultural uses do not require treated water. So while the primary uses require potable water and the secondary uses require non-potable water, but with some treatment to prevent compromising the building's plumbing, the agricultural and irrigation uses require no treatment whatsoever, and the water may be pumped directly to the point of use from the pump station 130. Therefore, in the event a demand is made for water at a point of use corresponding to agricultural or irrigation use, the water may be transferred from the pump station 130 to the point-of-use through the second outgoing conduit 137.
With reference now to FIG. 2, a rainwater treatment system 200 according to a preferred embodiment of the invention is provided. The rainwater treatment system 200 may be located within the building in which the treated water is to be used, or it may be located in a remote location. In some embodiments, one rainwater treatment system 200 supplies treated water for numerous buildings. The rainwater treatment system 200 includes a pressurizing device 210, a pH adjustment system 220, a filtration system 230, an ultraviolet disinfection system 240, and a chemical disinfection system 250. Each of the foregoing components of the rainwater treatment system 200 is connected via conduits to at least one other component such that water may flow from one component to another through the conduits. The direction of flow between components in accordance with some embodiments is indicated by the arrows in FIG. 2. Therefore, as illustrated in FIG. 2, in some embodiments, water may flow through the conduits from the pressurizing device 210 to the pH adjustment system 220 to the filtration system 230 to the ultraviolet disinfection system 240 to the chemical disinfection system 250. It should be understood, however, that the configuration of the components illustrated in FIG. 2 is not exclusive; indeed, there are numerous other potential configurations that may be recognized by those skilled in the art that are within the scope of the present invention. Thus, in other embodiments, and as discussed in greater detail below, water may not flow between components in the manner illustrated in FIG. 2.
In some embodiments, the pressurizing device 210 is configured to receive water originating in the pump station 130 through an incoming conduit. The pressuring device 210, according to some embodiments, is further configured to pressurize the incoming water such that it may pass through the remaining components of the rainwater treatment system 200 and be usable at the point-of-use within the building. Therefore, the degree of pressurization is dependent upon the particular environment and configuration of the rainwater treatment system 200 as well as the particular components utilized in the rainwater treatment system 200. In some embodiments, the pressurizing device 210 is one or more hydro-pneumatic tanks. In addition to the incoming conduit, the pressurizing device 210 also has an outgoing conduit that is configured to carry the pressurized water to another component in the rainwater treatment system 200, which is, in some embodiments, the pH adjustment system 220.
Rainwater is generally acidic in nature. In some embodiments, the pH adjustment system 220 is configured to neutralize the acidity of the rainwater by raising the pH level. This advantageously reduces the potential corrosive damage that could be caused to the metal conduits and devices employed within the rainwater treatment system 200, as well as the general plumbing of the building, due to contact with the acidic rainwater. For that reason, in some embodiments, and as illustrated in FIG. 2, the rainwater treatment system 200 is configured such that water is directed to the pH adjustment system 220 prior to any of the filtration or disinfection components. Alternatively, the pH adjustment system 220 may be positioned within the rainwater treatment system 220 such that the water must pass through various other filtration and/or disinfection components prior to reaching the pH adjustment system 220, but such a configuration would not be as advantageous, as it would reduce the anti-corrosion benefits provided by the pH adjustment system 220 to the other system components.
Any type of pH adjustment system 220 now known or hereafter developed may be utilized in accordance with embodiments of the present invention. In some embodiments, the pH adjustment system 220 is simply one or more calcite filters that allow the water arriving from the pressurizing device 210 to pass through calcite media. Calcite filters may be a good choice for the pH adjustment system 220 because they are inexpensive and easy to maintain. In some embodiments, the pH adjustment system 220 is configured to direct the water, once its pH has been neutralized, through a conduit to another component of the rainwater treatment system, which is, according to some embodiments, the filtration system 230.
According to some embodiments, the filtration system 230 is configured to remove particulate matter and suspended solids from the water. Any number of devices may be utilized in the filtration system 230, including filtration systems now known or hereafter developed. According to different embodiments, the filtration system 230 may include disc filters, cartridge filters, membranes, or other filter media designed to remove solids from the water. Indeed the filtration system 230 may include a combination of different types of filter media or a series of filter media of the same type, but designed to filter out solids of different sizes. In some embodiments, the filtration system 230 is configured to remove particulate matter at or above 5 microns in size. In addition to the filter media, the filtration system 230 may also include, according to some embodiments, a backwash system to remove the captured particulate matter from the filtration system 230 and a cleaning device to maintain the filter media free from blockages and build-up. In some embodiments, pressure indicators 232 are provided on the incoming and outgoing ends of the filtration system 230 to measure the pressure drop across the filter(s). These pressure indicators 232 transmit the pressure differential measurements to a master system control panel 280, which may utilize the measurements to determine when replacement filter media is required.
According to some embodiments, the rainwater treatment system 200 is configured such that the water, upon passing through the filtration system 230, is directed to an ultraviolet (UV) disinfection system 240. In some embodiments, the UV disinfection system 200 includes a UV lamp(s) that irradiates bacteria and microorganisms present in the water passing through the UV chamber. While it is possible that rainwater treatment system 200 may be configured such that the UV disinfection system 240 is positioned such that the water reaches the UV disinfection system 240 prior to passing through the filtration system 230, it is preferable that the rainwater treatment system 200 is configured such that the water arriving at the UV disinfection system 240 for irradiation has already been filtered by the filtration system 230, as the presence of particulate matter in the water, particularly large suspended solids, can negatively impact the effectiveness of the UV irradiation process. Indeed, bacteria and microorganisms may be buried within such solids so that they are shielded from the UV light and may pass through the unit without being destroyed. Therefore, to maximize the efficacy of the UV disinfection system 240, according to some embodiments, the UV disinfection system 240 is configured to receive water transferred to it through conduits from the filtration system 230.
In some embodiments, a chemical disinfection system 250 is provided within the rainwater treatment system 200 such that the chemical disinfection system 250 is configured to receive through conduits the water that has just passed through the UV disinfection system 240. Therefore, according to some embodiments, the disinfection of the water being treated by the rainwater treatment system 200 is a two-stage process. The chemical disinfection system 250 may simply inject a chemical disinfecting solution such as chlorine into the water that is traveling through the conduits to the point-of-use, or the chemical disinfection system 250 may redirect the water into a chemical disinfection unit of some type. In some embodiments, the chemical disinfection system 250 is an onsite sodium hypochlorite generation system that both generates a chlorine solution and introduces the chlorine solution to the water to be treated. In other embodiments, the chemical disinfection system 250 is another type of chlorine disinfection system, such as tablet chlorinator. The onsite hypochlorite generation system may include, for example, a brine tank, a generator, a chemical storage tank, and a metering pump and the chlorine solution generated may be a 0.8% sodium hypochlorite solution. Regardless of the particular instruments utilized by or incorporated into the chemical disinfection system 250, the chemical disinfection system 250 is configured to introduce a disinfecting chemical solution into the water to provide additional disinfection (beyond that provided by the UV disinfection system 240) and a residual concentration of disinfectant that will advantageously prevent regrowth of bacteria and microorganisms in the water downstream.
There are various locations within the rainwater treatment system 200 that the chemical disinfection system 250 may be positioned without affecting the efficacy of the chemical disinfection system 250. Therefore, according to different embodiments, the chemical disinfection system 250 may be configured to introduce the disinfecting solution to water traveling through the rainwater treatment system 200 either before or after the water passes through the pH adjustment system 220, the filtration system 230, or the UV disinfection system 240, again to prevent biogrowth on these components of the treatment system. Indeed, in some embodiments, the chemical disinfection system 250 may be configured to introduce the disinfecting solution at more than one point in the rainwater treatment system 200. According to other embodiments, the chemical disinfection system 250 may be positioned and implemented within the rainwater treatment system 200 such that it treats only a predetermined portion or amount of water that is passing through the conduits of the rainwater treatment system 200. In some embodiments, rainwater treatment system 200 is configured such that after the water has been treated by the pH adjustment system 220, the filtration system 230, and the UV disinfection system 240, a particular amount or portion of the water is redirected to the chemical disinfection system 250, also known as a “recirculation loop.” According to such embodiments, the rainwater treatment system 200 may be configured such that the portion of water treated by the chemical disinfection system 250 is, after treatment, directed to rejoin the water in the conduits on the way to point-of-use.
Alternatively, according to other embodiments and as illustrated in FIG. 2, the rainwater treatment system 200 may be configured such that the water treated by the chemical disinfection system 250 is, after treatment, directed to join the water that has not yet been fed to any of the pH adjustment system 220, the filtration system 230, or the UV disinfection system 240. This creates a loop that allows continuous circulation of water through the pH adjustment system 220, the filtration system 230, and the UV disinfection system 240, even when there is no demand for water at the point-of-use. This is advantageous as certain systems within the rainwater treatment system 200, such as the UV disinfection system 240, may require a minimum flow rate. It is also advantageous because the chlorine present in the water may help prevent biogrowth on the devices utilized in the pH adjustment system 220, the filtration system 230, and the UV disinfection system 240.
In connection with the chemical disinfection system 250, according to some embodiments, several chlorine sensors are provided within the rainwater treatment system 200 to measure the residual chlorine level in the water passing through the system. In some embodiments, the chlorine sensors communicate the chlorine level measurements to the master system control panel 280, which is configured to direct the chemical disinfection system 250 to add more or less chlorine solution depending on the measurements in order to maintain a residual chorine level sufficient to prevent regrowth of bacteria. For example, in the event water is continuously circulating in the rainwater treatment system 200 due to no demand at the point-of-use, the chlorine sensors may indicate that sufficient levels of chlorine are present in the water due to previous introduction. According to some embodiments, this indication from the chlorine sensors would be recognized by the master system control panel 280, which would cause the chemical disinfection system 250 to cease introduction of additional chlorine into the water as the water passes through the chemical disinfection system 250. In this way, the amount of chlorine present in the water at the point-of-use is maintained at a relatively constant level, even if the water is recirculating in the system.
In addition to the components described in detail above, various other measurement tools may be provided in the rainwater treatment system 200 that interface with the master system control panel 280, which utilizes the signals from the tools to manage the processes of the components of the rainwater treatment system 200 discussed above. As previously discussed, pressure indicators 232 are provided on either end of the filtration system 230 and chlorine sensors are provided prior to introduction of the water to the chemical disinfection system 250. In addition to these tools, additional pressure indicators, chlorine sensors, flow meters, pH sensors, and other measurement tools may be provided to monitor the processes taking place within the rainwater treatment system 200. The master system control panel 280 is configured to receive transmissions from each of these tools, process the transmissions based on predefined rules, and take specific action (or instruct particular components of the rainwater treatment system 200 to take specific action) based on specific transmissions. For the purposes of example only, in the event a flowmeter indicates reduced flow, the master system control panel 280 may initiate an increase of the pressurization caused by the pressurizing device 110. Advantageously, the master system control panel 280 allows the rainwater treatment system 200 to be somewhat automated and to be managed and controlled when necessary by individuals through use of a computer.
As the systems of embodiments of the present invention have been described above, exemplary embodiments of methods of recovering and treating rainwater shall now be described with reference to FIGS. 4 and 5. FIG. 4 is a flow chart that illustrates method of recovering and managing rainwater in anticipation of secondary use in buildings, according to some embodiments of the invention and FIG. 5 is a flow chart that illustrates a method of treating rainwater for secondary use in buildings, according to some embodiments of the invention.
As represented by block 402 of FIG. 4, falling rain is captured by a rainwater capturing device 110 on the roof of a building and conveyed via the storage conduits 112 to the cistern 120 for storage. From the cistern, as shown in block 404, the stored rainwater may be pumped into the pump station 130 through the first incoming conduit 131 of the pump station 130 in anticipation of use. In some embodiments, the operations of the pump station 130 are controlled by the pump station control panel 135. In certain embodiments, the pump station control panel 135 operates the pumps 133 within the pump station 130 in order to maintain the level of water stored in the pump station 130 at a particular level, as measured by the level measuring devices 134.
As represented by block 406, the pump station control panel 135 determines whether the rainwater pumped into the pump station 130 from the cistern 120 is sufficient to cause the level of water in the pump station 130 to meet the desired level. If it is not, as shown in block 408, the pump station control panel 135 operates the pumps 133 to pump reclaimed water originating in a wastewater treatment plant 150 into the pump station 135 to make up the deficit. In this way, there is always a certain amount of water (whether rainwater, reclaimed water, or a combination) in the pump station 130 to be transferred to the rainwater treatment system 200 on demand from a point-of-use in the building or elsewhere. Therefore, according to some embodiments, and as represented by block 410, in the event there is a demand for secondary use within the building, water is pumped from the pump station 130 to the rainwater treatment system 200 to be treated by the rainwater treatment system 200 prior to reaching the point of use. Alternatively, and also in accordance with block 410, in the event there is a demand for irrigation use, the water from the pump station 130 is pumped directly to the point of use.
Now referring to FIG. 5, when the water from the pump station 130 is pumped to the rainwater treatment system 200 for indoor secondary uses, it undergoes a method of treatment, an example of which is illustrated in FIG. 5. First, as represented by block 502, the water is pressurized by the pressurizing device 210 to ensure that the water may flow through the conduits and each component of the rainwater treatment system 200 and arrive at the point of use with enough pressure to be usable. Next, as represented by block 504, the water is neutralized by the pH adjustment system 220. In some embodiments, the water passes through calcite filters that reduce the acidity of the water. After the pH has been neutralized, and as represented by block 506, the water is filtered by a filtration system 230 to remove particulate matter and suspended solids at or above a certain size in diameter. From there, according to some embodiments and as shown in block 508, the water then flows through a UV disinfection system 240 that utilizes light from an ultraviolet lamp to irradiate bacteria and microorganisms.
In some embodiments, following UV disinfection, a chlorine sensor is utilized to measure the residual level of chlorine in the water and the master system control panel 280 compares the measurement to a specified desired amount of residual chlorine. As represented by block 510, the master system control panel 280 makes a determination as to whether the residual level of chlorine in the water is adequate. If it is determined that the chlorine level is not adequate, a chlorine solution is introduced into the water by a chemical disinfection system 240 such as an onsite sodium hypochlorite generation system or other chlorination systems, and as represented by block 512. In the event it is determined that the chlorine level is adequate, perhaps due to recirculation of water through the rainwater treatment system 200, no additional chlorine will be added. Once all of the foregoing actions have been taken, according to some embodiments and as shown in block 514, the water leaves the rainwater treatment system 200 and travels through the plumbing of the building to the point of secondary use.
While certain exemplary embodiments have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative of and not restrictive on the broad invention, and that this invention not be limited to the specific constructions and arrangements shown and described, since various other changes, combinations, omissions, modifications and substitutions, in addition to those set forth in the above paragraphs, are possible. Those skilled in the art will appreciate that various adaptations and modifications of the just described embodiments can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.

Claims

1. A rainwater recovery and treatment system for secondary use, the system comprising:

a rainwater capturing device configured to capture falling rainwater;

a pump station configured to receive the rainwater captured by the rainwater capturing device;

a pH adjustment device configured to neutralize the pH of the rainwater;

a filtration device configured to remove particulate matter from the rainwater;

an ultraviolet disinfection device configured to irradiate the rainwater with ultraviolet light; and

a chemical disinfection device configured to introduce chlorine into the rainwater.

2. The system of claim 1, further comprising:

a rainwater storage device configured to store water and connected via a first conduit to the rainwater capturing device and via a second conduit to the pump station, wherein the rainwater captured by the rainwater capturing device flows through the first conduit into the rainwater storage device for storage and then flows through the second conduit into the pump station.

3. The system of claim 2, wherein the rainwater storage device is a cistern.

4. The system of claim 2, wherein the rainwater storage device is buried underground and comprises an impervious liner and stone fill.

5. The system of claim 2, wherein the rainwater storage device is integrated into another water management system.

6. The system of claim 1, wherein the rainwater capturing device is located on the roof of a building.

7. The system of claim 1, wherein the rainwater capturing device comprises the roof of a building.

8. The system of claim 1, wherein the pump station is configured to utilize at least one level measuring device and a pump station control system to maintain the level of water held by the pump station within a particular range of levels.

9. The system of claim 1, further comprising:

a pressurizing device configured to pressurize the rainwater prior to it passing through any of the pH adjustment device, the filtration device, the ultraviolet disinfection device, or the chemical disinfection device.

10. The system of claim 9, wherein the pressurizing device comprises at least one hydro-pneumatic tank.

11. The system of claim 1, wherein the pH adjustment device comprises at least one calcite filter.

12. The system of claim 1, wherein the filtration device comprises at least one of the following: a disc filter, a cartridge filter, or a membrane filter.

13. The system of claim 1, wherein the chemical disinfection device comprises an on-site hypochlorite generating system or a tablet chlorinator.

14. The system of claim 1, further comprising a chlorine sensor configured to measure the level of chlorine present in water and a master control system configured to receive transmissions from the chlorine sensor and interface with the chemical disinfection device, wherein the master control system is configured to cause the chemical disinfection device to adjust the amount of chlorine introduced into the water based on a transmission from the chlorine sensor.

15. A water recovery and treatment system for secondary use, the system comprising:

a rainwater storage device configured to store rainwater;

a pump station configured to receive rainwater from the rainwater storage device and reclaimed water, wherein the pump station is further configured to receive reclaimed water only in the event the pump station is unsuccessful in receiving a predetermined volume of rainwater from the rainwater storage device; and

a water treatment system.

16. The system of claim 15, wherein the rainwater storage device is a cistern.

17. The system of claim 15, wherein the rainwater storage device is buried underground and is comprised of an impervious liner and stone fill.

18. The system of claim 15, wherein the rainwater storage device is integrated into another water management system.

19. The system of claim 15, wherein the pump station is configured to utilize a level measuring device and a pump station control system to maintain the level of water held by the pump station within a particular range of levels.

20. The system of claim 19, wherein the pump station control system is configured to receive signals from the level measuring device that cause the pump station to receive rainwater from the rainwater storage device.

21. The system of claim 20, wherein the pump station control system is configured to cause the pump station to receive reclaimed water in the event the pump station is unsuccessful in obtaining a predetermined volume of rainwater from the rainwater storage device.

22. The system of claim 15, wherein the water treatment system comprises

a pH adjustment device configured to neutralize the pH of water;

a filtration device configured to remove particulate matter from water;

an ultraviolet disinfection device configured to irradiate water with ultraviolet light; and

a chemical disinfection device configured to introduce a chlorine into water.

23. The system of claim 22, further comprising:

a pressurizing device configured to pressurize water prior to it passing through any of the pH adjustment device, the filtration device, the ultraviolet disinfection device, or the chemical disinfection device.

24. The system of claim 23, wherein the pressurizing device comprises at least one hydro-pneumatic pump.

25. The system of claim 22, wherein the pH adjustment device comprises at least one calcite filter.

26. The system of claim 22, wherein the filtration device comprises at least one of the following: a disc filter, a cartridge filter, or a membrane filter.

27. The system of claim 22, wherein the chemical disinfection device comprises an on-site hypochlorite generating system or a tablet chlorinator.

28. The system of claim 22, further comprising a chlorine sensor configured to measure the level of chlorine present in water and a master control system configured to receive signals from the chlorine sensor and interface with the chemical disinfection device, wherein the master control system is configured to cause the chemical disinfection device to adjust the amount of chlorine introduced into the water based on a signal from the chlorine sensor.

29. A method of recovering and treating rainwater for secondary use within a building, the method comprising:

capturing rainwater utilizing a rainwater capturing device;

storing the rainwater in a rainwater storage device;

neutralizing the pH of the rainwater;

filtering the rainwater to remove particulate matter;

irradiating the rainwater with ultraviolet light; and

introducing a chlorine solution into the rainwater.

30. The method of claim 28, further comprising,

obtaining reclaimed water; and

combining the reclaimed water with the rainwater.

31. The method of claim 29, wherein the reclaimed water is obtained from a water treatment plant.

32. The method of claim 29, wherein the reclaimed water is combined with the rainwater prior to said neutralizing, filtering, irradiating, and introducing steps.

33. The method of claim 31, wherein the reclaimed water and the rainwater are combined in a pump station.

34. The method of claim 28, wherein the rainwater capturing device comprises a roof of a building.

35. The method of claim 28, wherein the rainwater storage device is buried underground, and comprises an impervious liner and stone fill.

36. A product comprising water produced by a method comprising:

capturing rainwater utilizing a rainwater capturing device;

storing the rainwater in a rainwater storage device;

neutralizing the pH of the rainwater;

filtering the rainwater to remove particulate matter;

irradiating the rainwater with ultraviolet light; and

introducing a chlorine solution into the rainwater.

37. A system for the supply of water for secondary use, the system comprising:

a building comprising a rainwater capturing device and a rainwater treatment unit;

a water storage device comprising a cistern and a pump station, wherein the water storage device is configured to receive rainwater from the rainwater capturing device and reclaimed water, combine the rainwater and the reclaimed water, and transfer the combined rainwater and reclaimed water to the building for treatment by the water treatment system.

38. The system of claim 36, wherein the water treatment system comprises:

a pH adjustment device configured to neutralize the pH of acidic water;

a filtration device configured to remove particulate matter;

a chemical disinfection device configured to introduce a chlorine solution into water.