AU2017100442A4 - An Improved Module, System and Method for Treating Effluent - Google Patents

Abstract

Abstract The invention provides a module (1) for treating effluent (2) comprising a first chamber (4) and a second chamber (5). The first chamber (4) comprises an electrolytic cell (10, 28). The electrolytic cell (10, 28) may have a first electrode (17a) to remove contaminant particles (11) from the effluent and produce a treated effluent (12) and a second electrode (17b) to disinfect the treated effluent. The second chamber (5) may have a second electrolytic cell (30) to disinfect the treated effluent and a conduit (25) fluidly connecting the first and second chambers. A system (40) is provided where a sensor (50) detects the effluent level in a tank (41) and operates a pump (51) to transfer effluent into the module (1, 24) when a threshold level is reached in the tank. Methods for treating effluent are also provided by the invention. Figure 1 21 17b 7 11 clear water flows O to the outlet Figure 1

Description

-1 - 2017100442 24 Apr 2017 "An Improved Module, System and Method for Treating Effluent"

Field of the Invention [0001] The invention relates to a module, system and method for treating effluent and in a particular to a module, system and method for treating effluent from a collection well or a septic tank. The invention has been developed primarily for use in treating domestic wastewater will be described hereinafter by reference to this application.

Background of the Invention [0002] The following discussion of the prior art is intended to present the invention in an appropriate technical context and allow its advantages to be properly appreciated. Unless clearly indicated to the contrary, however, reference to any prior art in this specification should not be construed as an express or implied admission that such art is widely known or forms part of common general knowledge in the field.

[0003] For about the last 150 years, a collection well or a septic tank has been used to provide primary treatment of wastewater from human dwellings that are remote from or unconnected to sewage treatment networks. At present, around 20% of Australian homes are not connected to central sewer systems.

[0004] In a septic tank, the wastewater typically separates into three components. A first component generally comprises scum that floats to the top of the tank, a second component generally comprises solids settles towards the bottom of the tank and a third component generally comprises liquid between the first and second components. After sedimentation of the solids and other biological processes, the liquid (generally called effluent) is discharged from the septic tank into a designated transpiration area onsite. Further treatment of the effluent occurs in the soil.

[0005] However, the effluent is still septic in nature and thus has potential health risks with the potential to spread waterborne diseases. For this reason the installation and ongoing management of these wastewater treatment systems is highly regulated and must comply with Australian standards such as AS1546.3 and AS/NZS 1547. Also, regulators are increasingly requiring advanced secondary treatment of the effluent for virtually all new dwellings built in Australia today. Regulations now generally require that 2017100442 24 Apr 2017 -2- all new on site wastewater systems must use an additional biological treatment process generally employing an aeration stage (secondary treatment) after the septic tank (primary treatment).

[0006] Advanced secondary treatment domestic sewage plants are based on the activated sludge process, which uses a controlled application of bacteria and other microorganisms that feed on the organic sewage materials in the effluent to decompose them into sludge. These microorganisms are aerobic and require continuous aeration to supply them with oxygen. This biological process can take a long time for the bacteria to establish and act upon the solids.

[0007] The establishment of a suitable biological sludge can take several weeks and it can be susceptible to interference from foreign chemicals such as disinfectants, antibiotics and poisons in the wastewater draining into the system. Most systems accredited by the New South Wales State Health Department and other government health departments use a purpose built air blower which must operate 24 hours per day to supply oxygen and maintain the microorganisms that act on suspended organic matter. This air blower must also continue to operate whether the dwelling is occupied or not. For a household of up to 10 persons a typical air blower provides 80 litres of air per minute and requires about 50 to 80 watts of continuous electrical power. This equates to 115,000 litres of air daily that consumes 700 kWh of power annually.

[0008] These secondary systems often require the regular maintenance and the application of disinfectants such as chlorine, UV or ozone to kill harmful bacteria which can contribute to ground water contamination. For this reason, government regulations typically require that each system must be serviced 3 to 4 times annually by a trained and independent technician.

[0009] The Applicant developed a module, system and method for treating effluent that provided an improvement to existing systems and methods, and is the subject of Australian Innovation Patent No. 2014101038, whose specification as filed is hereby incorporated by reference in its entirely. While this module and system is effective, further alternative configurations would be beneficial to implementing this type of effluent treatment system and method. -3- 2017100442 24 Apr 2017 [0010] It is an object of the present invention to overcome or substantially ameliorate one or more of the disadvantages of prior art, or at least to provide a useful and/or improved alternative. It is an object of the invention in at least one preferred form to provide a treatment module, system and method for treating effluent from a domestic septic tank that is energy efficient without requiring an aeration system.

Summary of the Invention [0011] According to a first aspect of the invention, there is provided a module for treating domestic wastewater comprising effluent, the module comprising: a first chamber for receiving the effluent, the first chamber comprising an electrolytic cell for generating at least a first electrolytic reaction to remove contaminant particles from the effluent and produce a treated effluent; and a second chamber in fluid communication with the first chamber for receiving the treated effluent from the first chamber, wherein sludge is permitted to settle out of the treated effluent to produce clarified liquid, and an outlet for discharging the clarified liquid; wherein the electrolytic cell comprises a first electrode for generating the first electrolytic reaction and a second electrode for generating a second electrolytic reaction to substantially disinfect the treated effluent.

[0012] Preferably, the first electrode comprises a sacrificial electrode. In some embodiments, the sacrificial electrode comprises a first anode. In other embodiments, the sacrificial electrode comprises at least one of aluminium, iron, zinc, an aluminium compound, an iron compound and a zinc compound. In further embodiments, the sacrificial electrode comprises a waste metal, including aluminium cans or iron waste.

[0013] Preferably, the second electrode comprises at least partly a corrosion resistant material. More preferably, the second electrode comprises a second anode. In some embodiments, the second electrode is made from antimony-doped tin oxide, lead oxide or boron-doped diamond.

[0014] Preferably, the second electrode is made of a dimensionally stable material that forms on a surface of the second electrode bound by hydroxide cations. In some embodiments, the second electrode is made from platinum, iridium oxide, rubidium oxide or other noble metal. 2017100442 24 Apr 2017 -4- [0015] Preferably, the corrosion resistant material comprises a metal oxide, a semiconductor material or carbon in various forms. In some embodiments, the second electrode is made from graphene. In other embodiments, the corrosion resistant anode material comprises an array of mixed-metal oxide semiconductors.

[0016] Preferably, the second electrode comprises an inert cathode. In some embodiments, the second electrode is made from stainless steel or titanium. In other embodiments, the second electrode is made from titanium doped with rubidium and/or iridium.

[0017] Preferably, the second electrode is composed substantially of the corrosion resistant material. More preferably, the second electrode is composed of two or more corrosion resistant materials.

[0018] Preferably, the electrolytic cell comprises a third electrode for indicating a state of the electrolytic reaction. More preferably, the third electrode comprises an anode.

[0019] Preferably, the electrolytic cell comprises at least one cathode.

[0020] Preferably, the electrolytic cell comprises at least one cathode and a plurality of anodes. In other embodiments, the plurality of anodes comprises at least two anodes composed of different materials. In further embodiments, the plurality of anodes comprises at least one sacrificial anode and at least one non-sacrificial anode. In other embodiments, the electrolytic cell comprises at least the first electrode, the second electrode, the third electrode arranged as an electrode array. In yet another embodiment, the electrolytic cell comprises a plurality of the electrode arrays in the first chamber.

[0021] Preferably, the first electrolytic reaction generated by the first electrode produces electrically charged flocculants for attachment to the contaminant particles to remove the contaminant particles from the effluent. More preferably, the electrical flocculants comprise electrically charged gas bubbles, wherein the contaminant particles attached to the electrically charged gas bubbles float towards the surface of the effluent to form froth comprising the contaminant particles. -5- 2017100442 24 Apr 2017 [0022] Preferably, one or more of the electrodes are replaceable.

[0023] Preferably, the electrolytic cell is connected to an electrical source to generate the first and second electrolytic reactions. More preferably, the electrical source is a solar powered electrical source. In one embodiment, the solar powered electrical source comprises a solar PV panel. In another embodiment, the solar PV panel is mountable to the tank.

[0024] Preferably, the first and second chambers are partly defined by a common wall. More preferably, the common wall comprises an opening to place the first chamber in fluid communication with the second chamber. In some embodiments, the treated effluent flows through the opening from the first chamber to the second chamber. In other embodiments, the sludge flows from the second chamber through the opening to the first chamber for removal from the module.

[0025] Preferably, the second chamber has an inclined floor to remove the sludge from the second chamber. More preferably, the second chamber has a discharge outlet for removing the sludge from the module.

[0026] Preferably, the first chamber has an inclined floor to remove the sludge from the module. More preferably, the first chamber has a discharge outlet for removing the sludge from the module.

[0027] Preferably, the first and second chambers share a common floor. More preferably, the common floor is inclined to remove sludge from the module.

[0028] Preferably, the module comprises a conduit fluidly interconnecting the first chamber and the second chamber for transferring the treated effluent from the first chamber to the second chamber.

[0029] According to a second aspect of the invention, there is provided a module for treating domestic wastewater comprising effluent, the module comprising: a first chamber for receiving the effluent, the first chamber comprising a first electrolytic cell for generating a first electrolytic reaction to remove contaminant particles from the effluent and produce a treated effluent; and 2017100442 24 Apr 2017 -6- a second chamber in fluid communication with the first chamber for receiving the treated effluent from the first chamber, wherein sludge is permitted to settle out of the treated effluent in the first and/or second chambers to produce a clarified liquid; wherein the second chamber comprises a second electrolytic cell for generating a second electrolytic reaction to disinfect the treated effluent and/or the clarified liquid and an outlet for discharging the clarified liquid.

[0030] Preferably, a conduit fluidly connects the first and second chambers to convey the treated effluent to the second chamber. It is preferred that the conduit is configured to remove the sludge from the module. More preferably, the conduit comprises a discharge outlet for the sludge. In some embodiments, the conduit comprises a sump.

[0031] Preferably, the conduit, first chamber and second chamber form a U-shape. In one embodiment, the module comprises a U-shaped tube. More preferably, the first and second chambers comprise two arms of the U-shape. Alternatively, the conduit, first chamber and second chamber form a V-shape.

[0032] Preferably, the conduit fluidly connects the first and second chamber such that the treated effluent of the first chamber can be decanted to the second chamber. In one embodiment, the conduit comprises a decanting outlet.

[0033] Preferably, the first electrolytic cell comprises the first electrode of the first aspect of the invention.

[0034] Preferably, the second electrolytic cell comprises the second electrode of the second aspect of the invention.

[0035] The first and second electrolytic cells each preferably have the preferred features of the first aspect of the invention.

[0036] According to a third aspect of the invention, there is provided a system for treating domestic wastewater comprising effluent, the system comprising a plurality of modules according to the first or second aspect of the invention, wherein each of the modules are fluidly connected to each other. -7- 2017100442 24 Apr 2017 [0037] Preferably, the modules are connected in parallel. Alternatively, the modules are connected in series.

[0038] Preferably, the system comprises a tank for receiving the domestic wastewater, the tank being fluidly connected to one of the modules.

[0039] According to a fourth aspect of the invention, there is provided a system for treating domestic wastewater comprising effluent, the system comprising: a tank in fluid communication with the module of the first or second aspect of the invention, the tank for holding the domestic wastewater; a pump for transferring the effluent in the tank to the first chamber of the module; a pump controller for controlling operation of the pump; and a sensor for detecting the effluent level in the tank, the sensor being in electronic communication with the pump controller; wherein the pump controller operates the pump in response to the sensor detecting a first threshold level in the tank in order to transfer the effluent to the first chamber.

[0040] Preferably, the pump controller stops operation of the pump in response to the sensor detecting a second threshold level in the tank.

[0041] Preferably, the sensor actuates a switch in the pump controller when the detected effluent level reaches the first threshold level to operate the pump.

[0042] Preferably, the sensor actuates a switch in the pump controller when the detected effluent level reaches the second threshold level to cease operation of the pump.

[0043] Preferably, the sensor is a passive sensor.

[0044] Preferably, the sensor comprises a float sensor.

[0045] Preferably, the tank comprises a septic tank. Alternatively, the tank comprises a collection well. -8- 2017100442 24 Apr 2017 [0046] Preferably, an outlet of the tank is fluidly connected to the first chamber inlet.

[0047] Preferably, the module is located inside the tank. Alternatively, the module is located outside of the tank. In some embodiments, the module is located partly within the tank.

[0048] Preferably, the electrical source is mounted to the module. Alternatively, the electrical source is mounted to the tank. More preferably, the electrical source is a solar powered electrical source. In one embodiment, the solar powered electrical source comprises a solar PV panel.

[0049] Preferably, the tank comprises a septic tank. Alternatively, the tank comprises a collection well.

[0050] The system may also have the preferred features of the first, second or third aspects of the invention stated above, where applicable.

[0051] According to a fifth aspect of the invention, there is provided a method for treating domestic wastewater comprising effluent, the method comprising: receiving the effluent in a first chamber; generating a first electrolytic reaction in the first chamber with a first electrode to remove contaminant particles from the effluent and producing a treated effluent; generating a second electrolytic reaction in the first chamber with a second electrode to substantially disinfect the treated effluent; transferring the treated effluent from the first chamber into a second chamber; permitting sludge to settle out of the treated effluent to produce clarified liquid; and discharging the clarified liquid from an outlet of the second chamber.

[0052] Preferably, the method comprises using a sacrificial electrode as the first electrode. In some embodiments, the sacrificial electrode comprises a first anode.

[0053] Preferably, the method comprises using a corrosion resistant material to form at least part of the second electrode. More preferably, the second electrode comprises a second anode. In some embodiments, the method comprises using antimony-doped tin oxide, lead oxide or boron-doped diamond. 2017100442 24 Apr 2017 -9- [0054] Preferably, the method comprises using a dimensionally stable material to form the second electrode that forms on a surface of the second electrode bound by hydroxide cations. In some embodiments, the method comprises using platinum, iridium oxide, rubidium oxide or other noble metal.

[0055] Preferably, the method comprises using a metal oxide, a semiconductor material or carbon in various forms as the corrosion resistant material. In some embodiments, the method comprises using grapheme or an array of mixed-metal oxide semiconductors.

[0056] Preferably, the method comprises using an inert cathode as the second electrode. In some embodiments, the method comprises using stainless steel, titanium or titanium doped with rubidium and/or iridium.

[0057] Preferably, the method comprises providing the second electrode composed substantially of the corrosion resistant material. More preferably, the method comprises providing the second electrode composed of two or more corrosion resistant materials.

[0058] Preferably, the method comprises using a third electrode for indicating a state of the electrolytic reaction. More preferably, the method comprises using an anode as the third electrode.

[0059] Preferably, the method comprises using at least one cathode.

[0060] Preferably the method comprises using at least one cathode and a plurality of anodes. In other embodiments, the plurality of anodes comprises at least two anodes composed of different materials. In further embodiments, the plurality of anodes comprises at least one sacrificial anode and at least one non-sacrificial anode.

[0061] Preferably, the first electrolytic reaction generating step comprises producing electrically active flocculants for attachment to the contaminant particles to remove the contaminant particles from the effluent. More preferably, the first electrolytic reaction generating step comprises producing electrically charged gas bubbles, wherein the method further comprises permitting contaminant particles to attach to the electrically 2017100442 24 Apr 2017 -10- charged gas bubbles and float towards the surface of the effluent to form froth comprising the contaminant particles.

[0062] Preferably, the first electrolytic reaction generating step comprises providing an electrolytic cell in the first chamber. More preferably, the first electrolytic reaction generating step comprises providing at least two electrodes. In one embodiment, the first electrolytic reaction generating step comprises providing at least one sacrificial electrode. In some embodiments, the first electrolytic reaction generating step comprises providing a sacrificial electrode comprising at least one of aluminium, iron, zinc, an aluminium compound, an iron compound and a zinc compound. In other embodiments, the first electrolytic reaction generating step comprises providing a sacrificial electrode comprising a waste metal, including aluminium cans or iron waste.

[0063] Preferably, one or more of the electrodes are replaceable.

[0064] Preferably, the method comprises providing a plurality of electrodes. More preferably, the method comprises providing a plurality of anodes and a plurality of cathodes. In some embodiments, the method comprises providing a plurality of anodes and at least one cathode. In further embodiments, the method comprises providing the first anode, the second anode, the third anode and the at least one cathode as an electrode array. In other embodiments, the method comprises providing a plurality of the electrode arrays in the first chamber.

[0065] Preferably, the method comprises connecting the electrolytic cell to an electrical source. More preferably, the method comprises connecting the electrolytic cell to a solar powered electrical source. In one embodiment, the solar powered electrical source comprises a solar PV panel. In another embodiment, the method comprising mounting the solar PV panel to the tank.

[0066] Preferably, the method comprises providing a common wall partly defining the first and second chambers. More preferably, the method comprises providing an opening in the common wall to place the first chamber in fluid communication with the second chamber. In some embodiments, the method comprises permitting the treated effluent to flow through the opening from the first chamber to the second chamber. In 2017100442 24 Apr 2017 -11 - other embodiments, the method comprises permitting the sludge to flow from the second chamber through the opening to the first chamber for removal from the module.

[0067] Preferably, the method comprises providing the second chamber with an inclined floor to remove the sludge from the second chamber. More preferably, the method comprises providing the second chamber with a discharge outlet for removing the sludge from the module.

[0068] Preferably, the method comprises providing the first chamber with an inclined floor to remove the sludge from the module. More preferably, the method comprises providing the first chamber with a discharge outlet for removing the sludge from the module.

[0069] Preferably, the method comprises providing the first and second chambers with a common floor. More preferably, the method comprises providing an inclined common floor to remove sludge from the module.

[0070] Preferably, the method comprises providing the first and second chambers as a module and locating the module inside the tank. Alternatively, the method comprises providing the first and second chambers as a module and locating the module outside of the tank. In some embodiments, the method comprises providing the first and second chambers as a module and locating the module partly within the tank.

[0071] Preferably, the method comprises providing the module with a conduit fluidly interconnecting the first chamber and the second chamber for transferring the treated effluent from the first chamber to the second chamber.

[0072] Preferably, the method comprises mounting the electrical source to the module. Alternatively, the method comprises mounting the electrical source to the tank. In one embodiment, the electrical source is a solar powered electrical source.

[0073] The method may also have the preferred features of the first, second, third and/or fourth aspects of the invention stated above, where applicable. -12- 2017100442 24 Apr 2017 [0074] According to a sixth aspect of the invention, there is provided a method for treating effluent, comprising: receiving the effluent in a first chamber; generating a first electrolytic reaction in the first chamber to remove contaminant particles from the effluent and producing a treated effluent; transferring the treated effluent from the first chamber into a second chamber; permitting sludge to settle out of the treated effluent to produce clarified liquid; generating a second electrolytic reaction in the second chamber to disinfect the treated effluent and/or clarified liquid; and discharging the clarified liquid from an outlet of the second chamber.

[0075] Preferably, the method comprises configuring the conduit to remove the sludge from the module. More preferably, the method comprises providing the conduit with a discharge outlet for the sludge. In some embodiments, the conduit comprises a sump.

[0076] Preferably, the method comprises forming the conduit, first chamber and second chamber into a U-shape. In one embodiment, the module comprises a U-shaped tube. More preferably, the first and second chambers comprise two arms of the U-shape. Alternatively, the conduit, first chamber and second chamber form a V-shape.

[0077] Preferably, the method comprises providing the first electrolytic cell with the first electrode of the first aspect of the invention.

[0078] Preferably, the method comprises providing the second electrolytic cell with the second electrode of the first aspect of the invention.

[0079] The method preferably comprises has the preferred features of the first, second and fifth aspects of the invention.

[0080] According to a seventh aspect of the invention, there is provided a method for treating domestic wastewater comprising effluent, the method comprising providing a plurality of modules according to the first or second aspect of the invention, wherein each of the modules are fluidly connected to each other.

[0081] Preferably, the method comprises connecting the modules in parallel. Alternatively, the method comprises connecting the modules in series. -13- 2017100442 24 Apr 2017 [0082] According to an eighth aspect of the invention, there is provided a method for treating domestic wastewater comprising effluent, the method comprising: providing a tank to hold the effluent; detecting the level of the effluent in the tank; transferring the effluent into a first chamber in response to the effluent level in the tank reaching a threshold level; generating an electrolytic reaction in the first chamber to remove contaminant particles from the effluent and producing a treated effluent; transferring the treated effluent from the first chamber into a second chamber; permitting sludge to settle out of the treated effluent to produce clarified liquid; and discharging the clarified liquid from an outlet of the second chamber.

[0083] Preferably, the method comprising preventing transfer of the treated effluent from the first chamber into a second chamber in response to the effluent level in the tank falling below the threshold level.

[0084] The method may also have the preferred features of the fifth, sixth, seventh or eighth aspects of the invention stated above, where applicable.

[0085] Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.

[0086] Also, throughout this specification unless explicitly stated otherwise, the term “froth” means bubbles or foam, including any agglomeration of thereof. In addition, throughout this specification unless explicitly stated otherwise, the term “sacrificial electrode” means an electrode that is consumed during an electrolytic reaction.

[0087] Furthermore, as used herein and unless otherwise specified, the use of the ordinal adjectives "first", "second", "third", etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner. - 14- 2017100442 24 Apr 2017

Brief Description of the Drawings [0088] Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: [0089] Figure 1 is a schematic cross-sectional view of a module according to an embodiment of the invention; [0090] Figure 2 is a schematic drawing of the electrolytic reaction in the module of Figure 1; [0091] Figure 3 is a schematic drawing of a system according to another embodiment of the invention; [0092] Figure 4 is a schematic drawing of a system according to a further embodiment of the invention; [0093] Figure 5 is a schematic cross-sectional view of a module according to another embodiment of the invention; and [0094] Figure 6 is schematic cross-sectional view of a module and system according to a further embodiment of the invention.

Preferred Embodiments of the Invention [0095] The present invention will now be described with reference to the following examples which should be considered in all respects as illustrative and non-restrictive. In the Figures, corresponding features within the same embodiment or common to different embodiments have been given the same reference numerals. While the embodiments of the invention are described in the context of a septic tank, it will be appreciated that the invention is also applicable to other wastewater treatment units that produce an effluent, such as collection wells.

[0096] Referring to Figure 1, a module 1 for treating effluent 2 from a septic tank (not shown) comprises a first chamber 4 and a second chamber 5 in fluid communication via an opening 6 in a common wall 7 shared by the first and second chambers 4, 5. In this 2017100442 24 Apr 2017 - 15- embodiment, the opening 6 is formed adjacent the shared floor 8 of the first and second chambers 4, 5.

[0097] The first chamber 4 comprises an inlet 9 for receiving effluent 2 from the septic tank and an electrolytic cell 10 to generate an electrolytic reaction that removes contaminant particles 11 from the effluent 2 to produce a treated effluent 12 that flows through the opening 6 into the second chamber 5.

[0098] The second chamber 5 receives the treated effluent 12 and permits sludge 13 to settle from the treated effluent to produce a clarified liquid 14, which then flows upwardly as indicated by arrow 15 and is discharged from the second chamber via an outlet 16. The disinfected clarified liquid can then be used for garden irrigation, toilet flushing or other grey water applications.

[0099] The electrolytic cell 10 in this embodiment comprises a bi-polar electrode array having a plurality of electrodes arranged alongside each other, with positive electrodes (anodes) 17a, 17b, 17c with negative electrodes (cathodes) 18. Each of the anodes 17a, 17b, 17c perform a different function; the anode 17a produces electrically charged flocculants in the form of electrically charged gas bubbles 19, the anode 17b disinfects the effluent 2 and the anode 17c acts to monitor the electrolysis reaction and detect any faulty operation of the electrolytic cell.

[00100] The anode 17c is connected to an input to the PLC (Programmable Logic Controller) control system to monitor changes in the electrical current density and to activate an alarm if the current density falls below a pre-set level. This might indicate conditions such as the formation of a non-conductive oxide layer on an anode or that the sacrificial electrode has been dissolved and needs replacing.

[00101] Most of the contaminant particles 11 attach or adhere to the electrically charged gas bubbles 19. The contaminant particles 11 include colloidal particles and other solids in suspension, as well as bacteria. Depending on the composition of the anodes 17 and cathodes 18, the gas bubbles 19 are composed of oxygen or hydrogen. The gas bubbles 19 then float towards the surface of the effluent 2, as shown by arrows 20, carrying the contaminant particles 11 upwardly and forming froth at the top of the - 16- 2017100442 24 Apr 2017 effluent. The froth is then removed from the first chamber 4 by an overflow launder (not shown) as indicated by arrow 21.

[0100] Heavier contaminant particles that are flocculated by the gas bubbles 19 but are too heavy to be carried upwards by the gas bubbles 19 descend, as shown by arrows 22, and slowly settle at the bottom of the shared floor 8 of the first chamber 4. Thus, a relatively contaminant-free treated effluent 10 is produced in the first chamber 4. At the same time, the electrolytic reaction generated by the anode 17b substantially disinfects the treated effluent 12 due to oxidation of bacteria, pathogens and other microorganisms in the effluent.

[0101] The sludge 13 that settles out of the treated effluent 12 is then removed via a drainage outlet 23 in the form of a sump. Any residual sludge in the treated effluent 12 in the second chamber 5 will also descend to the bottom at the shared floor 8. The shared floor 8 of the first and second chambers 4, 5 is inclined to facilitate movement of the sludge 13 to the sump 23. While the sump 23 is located at the bottom of the first chamber 4, it will be appreciated that the sump or any other form of the outlet can be located at the bottom of the second chamber 5 at the opposite end. In this case, the shared floor 8 will be inclined in the opposite direction to encourage movement of the sludge to the sump 23. The discharged sludge 13 may be transported to an onsite transpiration site or used as fertiliser for gardening or agricultural purposes.

[0102] Each of the anodes 17a, 17b, 17c have a different voltage (Voltage 1, Voltage 2, Voltage 3) due to their different composition, as they are each composed of different materials to perform their different functions, as described above, as best shown in Figure 2. The anode 17a is a sacrificial electrode is designed to gradually corrode, deplete or is otherwise consumed during the electrolytic reaction. In this embodiment, the anode 17a is made of aluminium and dissolves to form alum. The benefit of using aluminium is that the alum is insoluble and thus settles after flocculation. In addition, sacrificial aluminium plates (and iron plates) are known to produce Ions which attract all negatively charged particles including bacteria, causing their coagulation and sedimentation. This results in the effective removal of COD (chemical oxygen demand), SS (suspended solids), and turbidity from the wastewater system. Hence, the use of sacrificial electrodes advantageously reduces the risk of electrode fouling that can occur in electrolytic water treatment. - 17- 2017100442 24 Apr 2017 [0103] The amount of aluminium dissolved in the solution can be accurately determined with Faraday’s Law so that excessive alum generation can be avoided by controlling the electrical current supplied to the electrodes. Thus it is possible to adjust the life of the aluminium electrodes by varying the magnitude and duration the voltage applied to the aluminium anode(s).

[0104] The anode 17b is composed of a corrosion resistant material in order to disinfect the treated effluent 12. In this embodiment, the anode 17b is made of platinised titanium. However, other corrosion resistant material can be used, such as noble metals like iridium and ruthenium, similar transition metals to titanium, such as niobium and tantalum, or rubidium. The anode 17b can be made of a single corrosion resistant material or be an alloy or other composite as in the described embodiment. The titanium electrodes are not consumed and have an expected life of 5 years before replacement is required. Thus, the disinfection process can be greatly extended by varying the duration and voltage of electrical energy supplied to the titanium anodes.

[0105] It is preferred that disinfection is achieved by electrodes containing noble metals, such as using activated titanium anodes plated with platinum, rubidium or iridium among others. It has been recently demonstrated that electrolysis using these metals is a particularly effective disinfection mechanism which can inactivate bacteria by damaging bacterial cells and impairment of intracellular components especially the loss of DNA integrity. The reaction time for this process in for example toilet wastewater can inactivate microorganisms such as E. Coli and result in a 5-log10 reduction in viable E. Coli within 20 minutes of exposure.

[0106] The anode 17c is composed of carbon to monitor the electrolytic reaction and indicate when there is a fault or disruption to the electrolytic reaction.

[0107] The electrolytic cell 10 is powered by an electric source, which in this embodiment is a solar powered electrical source, such as a solar PV panel. In this way, the electrolytic cell 10 can operate without consuming electrical power from the electricity supply grid or other electrical generator. Thus, the module 1 is highly energy efficient and minimises electrical consumption compared to a standard aeration system. The electrical power for the module 1 is typically controlled with a PLC (programmable logic controller) to vary the polarity, frequency of the electrical pulse cycles, current density -18- 2017100442 24 Apr 2017 and voltage. It is possible to individually control the current density and duration of the electrical energy supplied to each electrode.

[0108] The electrolytic cell 10 is arranged so that each electrode 17, 18 is generally elongated so that one end protrudes from above the water level of the first chamber 4 while the other end forms part of the submerged treatment cell. The major benefit of this arrangement is that each electrode 17, 18 can be easily connected to the surface mounted bus bars (not shown) from the electrical power source. These bus bars hold the electrodes 17, 18 in place and because they are above or outside the water level, electrode replacement is greatly simplified.

[0109] Is generally known that, unless otherwise protected, the risk of corrosion occurs at the junction of dissimilar metals at the terminal junctions immersed in a liquid is a direct result of the electrolysis process. This corrosion effect can result in a significant impact on the long term reliability of the junction with dissimilar metals. It has been demonstrated that the electrochemistry between various electrodes can produce electrical power as a result of differences in the electric potential of each metal. The electrolysis process is not unlike that occurring in a typical chargeable lead acid battery.

It is contemplated that in other embodiments, a future configuration of electrodes using suitable materials can be constructed to provide rechargeable reserve power for the electrolytic cell 10 at times when solar or other power is interrupted.

[0110] Another embodiment of the invention is illustrated in Figure 3, in which the first chamber 4 and the second chamber 5 are configured as two arms of a U-shaped tube 24 fluidly connected by a conduit 25. In this embodiment, the treated effluent 12 flows through the conduit 25 in the form of a pipe form the first chamber 4 to the second chamber 5. The pipe 25 is located towards the bottom of the first chamber 4 to ensure that the froth containing the flocculated contaminate particles is not accidentally transferred into the second chamber 5.

[0111] Each of the first and second chambers 4, 5 have an electrolytic cell 28, 30 comprising anodes and cathodes. The electrolytic cell 28 in the first chamber 4 comprises aluminium anodes to produce the electrically charged flocculants in the form of electrically charged gas bubbles 19 to remove contaminant particles. The resulting froth 32 ascends to the top of the first chamber 4, as shown by arrows 20, where it is 2017100442 24 Apr 2017 -19- removed via an overflow launder (not shown). The sludge 13 descends, as shown by arrows 22, and collects in the pipe 25 for removal via the outlet 23. The treated effluent 12 then flows though the pipe 25 into the second chamber 5, where it is disinfected by the electrolytic cell 30 comprising the titanium anodes 17b as described above in relation to Figure 1. Any residual sludge 13 in the treated effluent 12 will also descend in the second chamber 5 into the pipe 5 for removal.

[0112] The module 24 operates in substantially the same manner as described in relation to the first embodiment. Hence, this second embodiment also avoids the need to use a filter to ensure separation of the settled sludge. However, the electro-flocculation and disinfection of the effluent in this embodiment occurs in separate stages, rather than being together as in the first embodiment.

[0113] The benefit in separating the flocculent and disinfection stages is that it is possible to return the foam and sludge generated by the sacrificial anodes to the primary collection well where they will react and settle with the incoming wastewater stream. The disinfection stage can be located within the storage chamber for the treated effluent without generating any significant sludge. In addition the anodes in the disinfection stage do not decompose and can be operated for longer periods to ensure continued disinfection of the treated effluent. That is, the flocculent stage carries out the coagulation of the effluent and forms the floating foam and combines with contaminants such as phosphorous to form insoluble sludge which settles to the bottom of the chamber. In contrast, the disinfection stage produces very little floating floes or settled sludge. Hence, it is preferable to separate these stages. Also, it is well known that human urine contains beneficial chemicals such as chloride and reactive oxygen species that form electrolytes that can enhance the overall disinfection efficiency thus eliminating the need to add any chemicals.

[0114] It will be appreciated that the conduit 25 can adopt a variety of configurations. For example, the conduit 25 can be inclined to direct or encourage the sludge 13 to flow towards the outlet 23. In another example, the conduit 25 can be V-shaped with a sump or outlet at the apex of the V-shape. The sharp inclination of the V-shape results in the sludge 13 flowing more quickly towards the sump or outlet for removal from the module. -20- 2017100442 24 Apr 2017 [0115] This embodiment operates under a “flooded plug flow” where the incoming effluent from the septic tank displaces an equal amount or equal volume of the electrolytic treated settled effluent 12 in the first chamber 4 into the second chamber 5 via the conduit 25. Thus, the volume of the effluent 2 being treated in the first chamber 5 is quiescent and balanced hydraulically across the module 24 (i.e. with the second chamber 5). The treated effluent 12 that flows into the second chamber 5 is disinfected by electrolytic cell 30 and does not mix with the treated effluent 12 in the first chamber 4. This is due to the fact that constant hydrostatic pressure exists at every level across the module 24 whenever the tank is in a quiescent state. The volume of the disinfected treated effluent 12 in second chamber 5 that overflows into the outlet 16 is equal to the volume of treated effluent 12 that enter the second chamber 5. It will be appreciated that in other embodiments, the module 24 shown in Figure 3 can be replaced with the module shown in Figure 1.

[0116] A variation to the conduit 25 in another embodiment is illustrated in Figure 4.

In this embodiment, the conduit 25 is configured to enable the treated effluent from the first chamber 4 to be decanted into the second chamber 5. In this embodiment, the conduit takes a general S-shape, with an inlet pipe 33, an elongate body 34, decanting pipe 35 and decanting outlet 36. The conduit 25 has a relatively smaller diameter to facilitate decanting of the treated effluent 12 and preventing the sludge 13 from inadvertently entering the conduit 25 at the inlet pipe section 31. The treated effluent 12 will flow through the conduit 25 due to displacement by the untreated effluent 3 entering the first chamber 4, as described in the paragraph above, up the elongate body 34, along the decanting pipe 35 and discharge out of the decanting outlet 36 and flow down into the second chamber 5, as shown by arrow 37. Air is optionally supplied through a tube or hose 38 connected to the conduit 25 (preferably at the elongate body 34) to assist in the decanting process. The settled sludge 13 collects at the bottom of the first chamber 4 for removal through an outlet indicated by arrow 39.

[0117] In other embodiments, the second chamber 5 is a vertical tube wholly located in a much larger first chamber 4. In this configuration the pipe 25 forms a sump into which the settled sludge accumulates.

[0118] Referring to Figures 5 and 6, an embodiment of a system according to the invention is illustrated, the system 40 comprising a septic tank 41 and the module 1 of -21 - 2017100442 24 Apr 2017 the first embodiment of the invention. The system 40 also comprises a sensor assembly 50 in electronic communication with a pump 51 fluidly interconnecting the tank 41 and the module 1 via conduits 53, 54. The sensor assembly 50 comprises an electronic controller 55 (such as a PLC) connected to a float 57 via a pivotable arm 58 that controls operation of the pump 51. Figures 4 and 5 illustrate the float 57 and arm 58 in an operative and inoperative position, as discussed in more detail below.

[0119] Movement of the float 57 up and down the tank 41 causes the pivotable arm 58 to rotate, activating a switch (not shown) in the controller 55 that operates the pump 51 to transfer effluent 2 from the tank 41 to the first chamber 4 of the module 1. Thus, when the level of the untreated effluent 2 in the tank 41 is at a minimum level, as indicated by dotted line 60, the switch in the controller 55 prevents operation of the pump 51. When the effluent level rises to a threshold level, as indicated by dotted line 61, the pivotable arm 58 triggers the switch in the controller 55 to actuate the pump 51 and transfer the effluent 2 into the first chamber 4 of the module 1.

[0120] In operation, wastewater generated within a home or human dwelling drains into the septic tank or a collection well, where some larger particles separate out from the wastewater and either float (such as fats) or settle as sludge to the base of the tank 41. This wastewater is generated by the normal usage of water utilities, such as grey water from washing, flushed toilet water and water used for baths and showers. As the effluent level rises in the tank 41, this causes the float 57 to rise and move the pivotable arm 58. Once the level of effluent in the tank 41 (and hence the float 57) reaches the threshold level, the pivotable arm 58 actuates the switch in the controller 55, causing the pump 51 to transfer the effluent 2 into the first chamber 4 of the module 1. When the effluent level in the tank 41 (and hence the float 57) falls to the minimum level 60, the pivotable arm 58 triggers the switch again and the controller 55 ceases operation of the pump 51, stopping further flow of effluent 2 into the first chamber 4.

[0121] The controller 55 may optionally then send a signal to the electrical power source in response to actuation of the pump 51. Where the electrical power source is a solar PV panel 25, it transmits electrical power to the electrolytic cell 10, which applies a low electrical voltage applied to electrodes 17,18 to generate an electrolytic reaction within the first chamber 4 using the effluent 2 as an electrolyte. The electrolytic reaction neutralises the electric charge and removes the contaminant particles 11 from the -22- 2017100442 24 Apr 2017 effluent 2 by creating small bubbles 19 of hydrogen and oxygen at the electrodes 17a, 18. These bubbles 19 bond to the charged contaminant particles 11 and float to the surface of the effluent in the first chamber 4 and form the froth 32. Simultaneously, the electrolytic reaction also disinfects the effluent 2 through oxidation of the bacteria. The froth 32 is removed from the treated effluent via a skimmer (not shown) and/or an overflow launder, leaving a relatively clear solution which, after sufficient exposure, becomes free of contaminants and any bacteria are disinfected.

[0122] The treated effluent 10 then flows through the opening 6 into the second chamber 15. The treated effluent 10 settles in the second chamber 5 to produce sludge 13 comprising any remaining insoluble scum that descends due to gravity to the bottom, leaving the clarified liquid 14 to be discharged through the outlet 16. The sludge 13 is removed by the sump or outlet 23 and can be periodically returned to the septic tank 41 via a return passage (not shown). The clarified liquid 14 can either be disposed on a transpiration area onsite for return back to the environment or, subject to meeting specified water quality standards, reclaimed and recycled for non-potable uses such as toilet flushing, car washing and garden irrigation.

[0123] The benefit of the system 40 is that it can detect when no wastewater is generated such as when the family is on vacation or the home is otherwise unoccupied. In this mode, the system 40 draws no power and does not smell. When wastewater flow is detected the system 40 immediately starts to operate and produces treated effluent within 1 hour. This is a considerable advantage over the conventional biological aeration treatment systems where the air blower must run continually to maintain the biological process. Without this air supply the conventional system starts to smell.

[0124] In some embodiments, the electrodes can simply be replaceable rather than sacrificial or otherwise are standard electrodes, such as chemically inert electrodes like carbon, zinc, platinum and semiconductors. The electrodes 17, 18 may also be made from cast iron slabs, various aluminium extrusions (such as bar, plate, box channel and tubular), perforated mesh or metal plate. It is envisaged that the electrolytic cell 10 may also have a combination of sacrificial, replaceable and/or chemically inert electrodes. However, it is preferred that aluminium or iron is used for at least one of the electrodes 17, 18 for the electrolytic cell 10 as they form aluminium or ferric compounds which are insoluble and thus settle after flocculation. 2017100442 24 Apr 2017 -23- [0125] In further embodiments, the electrodes are made from scrap or waste metal of suitable composition, such as aluminium cans or iron waste. This ability to use recyclable metal further reduces metal waste. In this case, either the consumed sacrificial electrode is removed and replaced with a fresh sacrificial electrode in the electrolytic cell 10 via an access opening (not shown) in the top of the first chamber 4 and/or second chamber 5. Alternatively, the entire electrolytic cell 10 is removed through the access opening and any consumed sacrificial electrodes are simply removed and replaced, and the electrolytic cell 10 is reinserted into the module 1,24.

[0126] Yet another embodiment uses electrodes 17, 18 composed of different materials to generate the electrolytic reaction. For example, the electrolytic cell 8 may comprise a series array with one zinc electrode and one carbon electrode. When the effluent flows between these electrodes a voltage is generated and electrolytic reaction commences. A further embodiment uses the electrodes as a storage battery that is charged during daylight hours using the solar PV panel and treats the effluent 2 during the night as it flows between the charged electrodes, such as lead plates.

[0127] It will be appreciated by those skilled in the art that the module 1 in the described embodiments advantageously enhances the natural settling action of the contents of the septic tank using electrolytic treatment in which sacrificial metal anode(s) and cathode(s) generate electrically active flocculants and produce tiny bubbles of hydrogen and oxygen to float and separate from the contaminated water comprising the effluent. This is achieved without the need to add chemical coagulating agents to settle out the organic and inorganic compounds.

[0128] The electrolytic reaction thus induces a flotation process that naturally achieves greatly enhanced water quality by removing colloidal particles and other suspended matter to reduce the TSS (total suspended solids), BOD (biochemical oxygen demand), nutrients such as TN (total nitrogen) and TP (total phosphorous). A significant advantage is that the treated effluent is disinfected without the need to add additional chemicals such as chlorine or treat with ozone or UV due to oxidation of bacteria, pathogens and other microorganisms during the electrolytic reaction. Various components of household wastewater (such as urine) already contain sufficient salts to ensure the electrolysis process operates directly on virtually all wastewater flows. The -24- 2017100442 24 Apr 2017 process is robust enough to treat wastewater containing bleach and other products which can inhibit the biological treatment processes.

[0129] In addition, the module 1 takes advantage of the diurnal cycle that typically occurs within a family home by not using any batteries to store the electrical power generated by the solar PV panel. That is, most activity takes place in daylight hours while less activity occurs at night when most family members are asleep. This diurnal cycle generally coincides or matches the period in which the module 1 is powered by sunlight falling on the solar PV panel 25. After sunset, solar power is unavailable and so the electrolysis treatment process ceases, further enabling the heavier contaminant particles to settle out of the effluent in the first chamber 4, as well as the sludge 13 to settle out of the flocculated effluent in the second chamber 5. This non-active period allowed the heavier flocculated contaminant particles time to settle, leaving a clear, odourless body of clarified water 14 ready for reuse, such as toilet flushing or irrigation onto the garden.

[0130] While the embodiment shown in Figures 4 and 5 take the form of a module 1 external of the septic tank 41, it will be appreciated that in other embodiments, the module 1,24 may be located within or partly within and partly without the tank 41, as described in Australian Innovation Patent No. 2014101038.

[0131] In other embodiments, electrical power to the module can be supplied electrical power sources other than a solar PV panel. For example, the electrical power for the module 1 can be obtained from any electricity grid connected source, local battery charger (such as a recreational vehicle or boat), stand alone wind or other solar power source. However, it is preferred that a solar powered electrical source is used as it is the most energy efficient option for operating the module and thus reduce consumption of electrical power and hence costs. Also, there is a plurality of solar panels instead of a single solar panel in other embodiments for larger scale applications. In addition, one or more storage batteries are used in other embodiments to permit the module 1 to operate where there is insufficient sunlight or at night, if desired.

[0132] In some embodiments, the module 1 can operate in continuous or batch mode. In other embodiments, a plurality of modules 1 can be provided to scale up or expand the system. The modules 1,24 are interconnected in series or parallel and can either have 2017100442 24 Apr 2017 -25- substantially the same size or have different sizes as required. Each module may have one or more first chambers fitted with various electrodes to perform differing functions, such as sacrificial electrodes made of aluminium or iron, or inert electrodes made of carbon, semiconductor or purpose designed alloys. The plurality of the modules 1,24 that are connected in parallel enhances the capacity to process higher volumes of wastewater while the plurality of modules connected in series may improve the quality of the clarified water.

[0133] In other embodiments, other forms and types of electrolytic cells are used instead of a bipolar electrode array, such as monopolar electrode arrays, alternating switched composite arrays, sequentially switched composite arrays, charged liquid injection, charged gas injection and various combinations of these electrolytic cells. Furthermore, the electrodes in some embodiments may be mounted anywhere in the first chamber 4 and/or second chamber 5, and in any orientation, aside from the mounting location and orientation shown in the Figures.

[0134] In some embodiments, the shape of the module 1,24 is hexagonal in plain view and each acts as a vertical column to provide additional strength and assist with mounting each module 1,24 to the outer water treatment tank. The diameter of each module 1,24 is such that it can be inserted into or removed from an existing septic tank through a universal tank access cover 600mm or more. This simplifies the ongoing maintenance of the module 1,24 and avoids any of the risks associated with working in confined spaces contaminated with dangerous sewage fumes.

[0135] In other embodiments, it is possible to mount additional electrolytic cells 10 alongside a single central cell in the module 1,24. By interconnecting connecting the electrolytic cells 10 the treatment volume can be increased and/or the additional stages can be added to increase final effluent quality. It is well known from the nature that the honeycomb structure achieved by grouping identically sized hexagonal shaped structures produces considerable advantages in increased strength without additional weight or fittings to support the structure. The hexagonal shape of each cell also counteracts the hydrostatic pressures resulting from the water pressure at depth in the tank. -26- 2017100442 24 Apr 2017 [0136] Also, in some embodiments, the module 1 has a plurality of first and/or second chambers so that there are several stages of treatment. Furthermore, one of the plurality of first chambers may use sacrificial electrodes in the electrolytic cell while another of the plurality of first chambers may use non-sacrificial electrodes (such as carbon, platinum, semiconductors, etc.) to achieve further treatment such as disinfection.

[0137] In other embodiments, the module 1 acts as a pre-treatment stage for further stages of treatment and/or microfiltration. In this case, the electrolytic based flotation process according to the invention is assisted with applied aeration either using separate air diffusers or introducing air through internal tubes in the electrodes 17, 18 of the electrolytic cell 10.

[0138] It is also contemplated that the module, system and method of the invention is applicable to the treatment of other types of contaminated water besides wastewater, such as water contaminated by fats, oils or even wine waste. For example, it is envisaged that the invention could also be used as a pre-treatment stage for a grease arrestor or grease trap, or to treat the output from some other contaminated water treatment unit.

[0139] While the embodiments of the invention employ conduit 25 and/or opening 6 placing the first and second chambers 4 and 5 into fluid communication, it will be appreciated that in other embodiments any combination of the opening or conduit may be used.

[0140] It will further be appreciated that any of the features in the preferred embodiments of the invention can be combined together and are not necessarily applied in isolation from each other. For example, the module 1 in the first embodiment may use the electrodes 30 from the second embodiment in the second chamber 5. Also, the module 1,24 can have both a solar powered electrical source as a primary power source and an electrical source connected to an electricity grid as a backup power source. Similar combinations of two or more features from the above described embodiments or preferred forms of the invention can be readily made by one skilled in the art.

[0141] By providing an electrolytic process to treat effluent from a septic tank, the invention removes contaminant particles and purifies the effluent without requiring -27- 2017100442 24 Apr 2017 expensive secondary treatment by biological stages such as aeration systems that consume significant electrical power. Thus, the invention significantly improving the treatment of effluent using less electrical power and at less cost while complying with regulations requiring secondary treatment of effluent.

[0142] Another advantage of the invention is that since the electrolytic reaction creates flocculants to bond to the contaminant particles, there is no need to add any chemicals such as aluminium sulphate, ferrous sulphate and ferric chloride, or other coagulating agents, to settle the organic and inorganic compounds in the effluent. Similarly, a further advantage of the invention is that the electrolytic reaction disinfects the treated effluent without the need to add additional chemicals such as chlorine, hydrogen peroxide or to treat with ozone or UV.

[0143] Yet another advantage of the invention is that the electrolysis time is also very fast (often less than 60 minutes) as against biological treatment (often taking more than 12 hours). As a consequence, this facilitates the use of smaller tanks to treat any given volume of effluent.

[0144] It thus be observed that by incorporating a U-shaped or V-shaped tube (as in Figure 3) or an under/over baffle (as in Figures 1 and 2) while placing the electrodes 17, 18 in at least the first chamber (i.e. at the top of the inlet side of the U-shaped or V-shaped tube), the hydrostatic pressure will naturally transfer treated clear water from the zone below the electrodes (this zone being separated by a baffle in Figures 1 and 2) to the second chamber 5. The treated water outlet is then slowly decanted from the top of second chamber 5 (such as the return arm of the U-shaped or V-shaped tube, or the conduit of Figure 4) thus eliminating all floating floes and without disturbing the settled solids.

[0145] In some embodiments, another advantage of the invention is that appropriate recycled waste metal (such as aluminium cans) is used for the sacrificial electrodes 17a (such as aluminium or iron) of the electrolytic cell 10, hence reducing the environmental impact of such waste.

[0146] A further advantage of the invention is that the module can be powered with low power, low voltage electricity supplied from the dwelling, local batteries or solar 2017100442 24 Apr 2017 -28- power where access to the grid is not possible. It is particularly advantageous to use solar power as this minimises or eliminates consumption of the electrical power from the gird, human dwelling or fossil fuelled electrical generator. As a single solar panel is sufficient to power the module 1, the solar panel can be simply contained in the lid of the tank or located nearby if necessary. The use of a solar panel enables a wastewater treatment system comprising the septic tank and module to be installed in locations or isolated places where access to the electrical grid is not available. For example, self-contained toilet facilities employing the wastewater treatment system can be provided as roadside toilets and similar facilities in national parks.

[0147] A major advantage of the module and system of the invention that the floes and settled solids after treatment are stable and do not recombine or smell in the treated water. This means the module or system can be switched off and then resume operation when power is restored. This mechanism also ensures that the diurnal cycle, solar power and the vacation modes can restart and operate reliably at any point in the treatment cycle. In contrast, typical biological treatment systems are not able to restore operation and will ultimately smell when the aeration process is interrupted for a significant time.

[0148] Also, due to its modular nature, the module 1 can be easily retrofitted to preexisting septic tanks as well as included as part of a new septic tank. Finally, the module is inherently low cost and involves low maintenance as it has no moving parts. In all these respects, the invention represents a practical and commercially significant improvement over the prior art. Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

Claims (69)

1. Claims

   1. A module for treating domestic wastewater comprising effluent, the module comprising: a first chamber for receiving the effluent, the first chamber comprising an electrolytic cell for generating at least a first electrolytic reaction to remove contaminant particles from the effluent and produce a treated effluent; and a second chamber in fluid communication with the first chamber for receiving the treated effluent from the first chamber, wherein sludge is permitted to settle out of the treated effluent to produce clarified liquid, and an outlet for discharging the clarified liquid; wherein the electrolytic cell comprises a first electrode for generating the first electrolytic reaction and a second electrode for generating a second electrolytic reaction to substantially disinfect the treated effluent.
2. 2. The module of claim 1, wherein the second electrode comprises at least partly a corrosion resistant material.
3. 3. The module of claim 2, wherein the corrosion resistant material comprises a metal oxide, a semiconductor material or carbon.
4. 4. The module of claim 1, the second electrode is made of a dimensionally stable material that forms on a surface of the second electrode bound by hydroxide cations.
5. 5. The module of claim 1, the second electrode comprises an inert cathode.
6. 6. The module of claim 1, wherein the second electrode comprises at least one of antimony-doped tin oxide, lead oxide, boron-doped diamond, graphene, platinum, iridium oxide, rubidium oxide, a noble metal, stainless steel, titanium or titanium doped with rubidium and/or iridium..
7. 7. The module of any one of the preceding claims, wherein the second electrode is composed of two or more corrosion resistant materials.
8. 8. The module of any one of the preceding claims, wherein the second electrode comprises a second anode.
9. 9. The module of any one of the preceding claims, wherein the first electrode comprises a sacrificial electrode.
10. 10. The module of claim 9, wherein the sacrificial electrode comprises a first anode.
11. 11. The module of any one of the preceding claims, wherein the electrolytic cell comprises a third electrode for indicating a state of the electrolytic reaction.
12. 12. The module of claim 11, wherein the third electrode comprises an anode.
13. 13. The module of any one of the preceding claims, wherein the electrolytic cell comprises at least one cathode and a plurality of anodes.
14. 14. The module of claim 13, wherein the plurality of anodes comprises at least one sacrificial anode and at least one non-sacrificial anode.
15. 15. The module of any one of claims 1 to 12, wherein the electrolytic cell comprises the first electrode, the second electrode and the third electrode arranged as an electrode array.
16. 16. The module of claim 15, wherein the electrolytic cell comprises a plurality of the electrode arrays in the first chamber.
17. 17. The module of any one of the preceding claims, wherein the first and second chambers are partly defined by a common wall.
18. 18. The module of claim 17, wherein the common wall comprises an opening to place the first chamber in fluid communication with the second chamber.
19. 19. The module of claim 17, wherein the treated effluent flows through the opening from the first chamber to the second chamber.
20. 20. The module of claim 17, wherein the sludge flows from the second chamber through the opening to the first chamber for removal from the module.
21. 21. The module of any one of the preceding claims, wherein the second chamber has an inclined floor to remove the sludge from the second chamber.
22. 22. The module of any one of the preceding claims, wherein the first chamber has an inclined floor to remove the sludge from the module.
23. 23. The module of claim 21 or 22, wherein the first or second chamber has a discharge outlet for removing the sludge from the module.
24. 24. The module of any one of the preceding claims, wherein the first and second chambers share a common floor.
25. 25. The module of claim 24, wherein the common floor is inclined to remove sludge from the module.
26. 26. The module of any one of the preceding claims, further comprising a conduit fluidly interconnecting the first chamber and the second chamber for transferring the treated effluent from the first chamber to the second chamber.
27. 27. A module for treating domestic wastewater comprising effluent, the module comprising: a first chamber for receiving the effluent, the first chamber comprising a first electrolytic cell for generating a first electrolytic reaction to remove contaminant particles from the effluent and produce a treated effluent; and a second chamber for receiving the treated effluent from the first chamber, wherein sludge is permitted to settle out of the treated effluent in the first and/or second chambers to produce a clarified liquid; wherein the second chamber comprises a second electrolytic cell for generating a second electrolytic reaction to disinfect the treated effluent and/or the clarified liquid and an outlet for discharging the clarified liquid; and wherein a conduit fluidly connects the first and second chambers to convey the treated effluent to the second chamber.
28. 28. The module of claim 27, wherein the conduit is configured to remove the sludge from the module.
29. 29. The module of claim 27 or 28, wherein the conduit comprises a discharge outlet for the sludge.
30. 30. The module of any one of claims 27 to 29, wherein the first chamber is fluidly connectable to the tank for recycling settled contaminant particles from the first chamber to the tank.
31. 31. The module of any one of claims 27 to 30, wherein the conduit, first chamber and second chamber form a U-shape.
32. 32. The module of any one of claims 27 to 31, wherein the conduit is inclined to facilitate removal of the sludge from the module.
33. 33. The module of claim 32, wherein the conduit comprises an outlet for removing the sludge from the module.
34. 34. The module of any one of claims 27 to 33, wherein the first electrolytic cell comprises a first electrode comprising a sacrificial electrode.
35. 35. The module of any one of claims 27 to 34, wherein the second electrolytic cell comprises a second electrode comprising at least partly a corrosion resistant material.
36. 36. The module of claim 35, wherein the corrosion resistant material is selected from the group consisting essentially of metal oxide, a semiconductor material, carbon and a dimensionally stable material that forms on a surface of the second electrode bound by hydroxide cations.
37. 37. The module of claim 27, wherein the second electrolytic cell comprises a second electrode, the second electrode comprising comprises an inert electrode.
38. 38. The module of claim 27, wherein the second electrolytic cell comprises a second electrode, the second electrode comprising at least one of antimony-doped tin oxide, lead oxide, boron-doped diamond, graphene, platinum, iridium oxide, rubidium oxide, a noble metal, stainless steel, titanium or titanium doped with rubidium and/or iridium.
39. 39. The module of any one of claims 35 to 38, wherein the second electrode is composed of two or more corrosion resistant materials.
40. 40. The module of any one of claims 27 to 39, wherein the second electrolytic cell comprises a sacrificial electrode.
41. 41. The module of any one of claims 27 to 40, wherein the first and/or second electrolytic cell comprises a third electrode for indicating a state of the electrolytic reaction.
42. 42. The module of any one of claims 27 to 41, wherein the first and/or second electrolytic cell comprises at least one cathode and a plurality of anodes.
43. 43. The module of claim 42, wherein the plurality of anodes comprises at least one sacrificial anode and at least one non-sacrificial anode.
44. 44. The module of any one of claims 35 to40, wherein the first and/or second electrolytic cell comprises a first electrode, the second electrode and a third electrode arranged as an electrode array, wherein the first electrode is a sacrificial electrode for producing electrically charged flocculants for attachment to the contaminant particles to remove the contaminant particles from the effluent and the third electrode is for indicating a state of the electrolytic reaction.
45. 45. The module of claim 44, wherein the electrolytic cell comprises a plurality of the electrode arrays in the first chamber.
46. 46. A system for treating domestic wastewater comprising effluent, the system comprising a plurality of modules according to any one of the preceding claims, wherein each of the modules are fluidly connected to each other.
47. 47. The system of claim 46, wherein the modules are connected in parallel.
48. 48. The system of claim 46, wherein the modules are connected in series.
49. 49. The system of any one of claim 46 to 48, wherein a tank for receiving the domestic wastewater is in fluid communication with at least one of the modules.
50. 50. A system for treating domestic wastewater comprising effluent, the system comprising: a tank in fluid communication with the module of any one of claims 1 to 45, the tank for holding the domestic wastewater; and a pump for transferring the effluent in the tank to the first chamber of the module; a pump controller for controlling operation of the pump; and a sensor for detecting the effluent level in the tank, the sensor being in electronic communication with the pump controller; wherein the pump controller operates the pump in response to the sensor detecting a first threshold level in the tank in order to transfer the effluent to the first chamber.
51. 51. The module of claim 50, the pump controller stops operation of the pump in response to the sensor detecting a second threshold level in the tank.
52. 52. A method for treating domestic wastewater comprising effluent, the method comprising: receiving the effluent in a first chamber; generating a first electrolytic reaction in the first chamber with a first electrode to remove contaminant particles from the effluent and producing a treated effluent; generating a second electrolytic reaction in the first chamber with a second electrode to substantially disinfect the treated effluent; transferring the treated effluent from the first chamber into a second chamber; permitting sludge to settle out of the treated effluent to produce clarified liquid; and discharging the clarified liquid from an outlet of the second chamber.
53. 53. The method of claim 52, comprising using a corrosion resistant material to form at least part of the second electrode.
54. 54. The method of claim 52, comprising using a dimensionally stable material to form the second electrode that forms on a surface of the second electrode bound by hydroxide cations.
55. 55. The method of claim 52, comprising using a metal oxide, a semiconductor material or carbon to form the second electrode.
56. 56. The method of claim 52, comprising using, to form the second electrode, at least one of antimony-doped tin oxide, lead oxide, boron-doped diamond, graphene, platinum, iridium oxide, rubidium oxide, a noble metal, stainless steel, titanium or titanium doped with rubidium and/or iridium.
57. 57. The method of any one of claims 52 to56, comprising using the first electrode to produce electrically active flocculants for attachment to the contaminant particles to remove the contaminant particles from the effluent.
58. 58. The method of any one of claims 52 to 57, comprising using a third electrode for indicating a state of the electrolytic reaction.
59. 59. The method of any one of claims 52 to 58, comprising providing a common wall partly defining the first and second chambers.
60. 60. The method of claim 59, comprising providing an opening in the common wall to place the first chamber in fluid communication with the second chamber.
61. 61. The method of any one of claims 52 to 60, comprising providing the first and/or second chamber with an inclined floor to remove the sludge from the first and/or second chamber.
62. 62. A method for treating domestic wastewater comprising effluent, the method comprising: receiving the effluent in a first chamber; generating a first electrolytic reaction in the first chamber to remove contaminant particles from the effluent and producing a treated effluent; transferring the treated effluent from the first chamber into a second chamber; permitting sludge to settle out of the treated effluent to produce clarified liquid; generating a second electrolytic reaction in the second chamber to disinfect the treated effluent and/or clarified liquid; and discharging the clarified liquid from an outlet of the second chamber.
63. 63. The method of claim 62, comprising configuring the conduit to remove the sludge from the module.
64. 64. The method of claim 62 or 63, comprising providing the conduit with an inclined floor to remove the sludge.
65. 65. The method of any one of claims 62 to 64, comprising forming the conduit, first chamber and second chamber into a U-shape.
66. 66. The method of any one of claims 62 to 65, comprising using sacrificial electrode in the first chamber to generate the electrolytic reaction and produce electrically active flocculants for attachment to the contaminant particles to remove the contaminant particles from the effluent.
67. 67. The method of any one of claims 62 to 66, comprising using an electrode composed of a corrosion resistant material to disinfect the treated effluent.
68. 68. The method of one of claims 62 to 66, comprising using an electrode composed of at least one of antimony-doped tin oxide, lead oxide, boron-doped diamond, graphene, platinum, iridium oxide, rubidium oxide, a noble metal, stainless steel, titanium or titanium doped with rubidium and/or iridium.
69. 69. The method of any one of claims 62 to 68, comprising using a third electrode for indicating a state of the electrolytic reaction.