Method and apparatus for treating wastewater to generate non-potable water

Abstract

The present invention relates to a method and apparatus for treating wastewater to produce non-potable water, wherein the method and apparatus perform a purification treatment including coarse filtration of the wastewater, preferably aerobic biopurification with sedimentation of particles and suspended solids, followed by ultrafiltration, preferably ultrafiltration by a membrane filter, and the purification treatment is controlled according to the contamination of the wastewater, at least with respect to biopurification and ultrafiltration.

Description

Technical Field

[0001] The present invention relates to a method for treating miscellaneous wastewater to produce miscellaneous water.

Background Art

[0002] Using miscellaneous wastewater from households (drainage from bathtubs, showers, washing machines, kitchens) for purposes such as toilet flushing water, garden watering, and cleaning is a means of saving drinking water resources. The requirements for purified miscellaneous wastewater (= miscellaneous water) are defined as follows in the relevant regulations and DIN / EN standards. · It must be completely hygienic. · The water should be transparent, odorless, and contain no other residues.

[0003] Since this water may be stored in, for example, a toilet tank for up to four weeks, it must be suitable for storage.

[0004] In Germany, such water is also called "Pflegewasser (care water)", and it is considered that with an appropriate legal framework, it will be possible to use it for showering and bathing in the future.

[0005] As prior art, various methods are known, ranging from chlorine treatment and ultraviolet (UV) treatment of miscellaneous wastewater to membrane filtration. The treatment results of miscellaneous wastewater based on the prior art are not satisfactory, and the reason is that different influencing factors / parameters interfere with each other.

[0006] As prior art, only Patent Document 1 is cited as an example. The method disclosed therein has room for improvement regarding the quality of miscellaneous water.

[0007] A key point to consider here is that, as water resources become increasingly scarce, it will become necessary to purify at least mildly contaminated water for reuse. Defining terms is crucial to providing a broader explanation of the underlying circumstances.

[0008] Non-potable water refers to water that can be used for commercial, industrial, agricultural, or similar purposes, depending on different quality requirements. The basis for this definition is specified in DIN 4046.

[0009] Graywater refers to wastewater discharged from showers, bathtubs, washbasins, kitchens, and even household washing machines. It should be noted that wastewater from toilets and other drainage systems is not included in the category of graywater.

[0010] Rainwater refers to natural precipitation such as rain, snow, dew, and fog. The rainwater is not contaminated by use. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] German Patent Application Publication No. 102008049970 Specification [Overview of the Initiative] [Problems that the invention aims to solve]

[0012] The objective of the present invention is to treat wastewater and / or rainwater in order to produce non-potable water of sufficiently good quality without discharging the wastewater as wastewater.

[0013] Efforts to treat wastewater and / or rainwater to generate non-potable water are based on the assumption that the average German citizen consumes approximately 120 liters of drinking water per day. The majority of these are used for personal hygiene purposes. The resulting wastewater, commonly known as "graywater," could account for approximately 50% of all household wastewater. Typically, these are flushed down the drain without being reused. In particular, in today's world, where climate change and the resulting heat waves and droughts are becoming increasingly severe, such actions constitute a significant waste of precious resources.

[0014] Proper and effective wastewater treatment contributes to environmental protection and also leads to cost reduction. The collected and treated wastewater can be used for toilet flushing, washing machine water, or garden watering. By utilizing wastewater, the consumption of drinking water can be significantly reduced. As a result, cost reductions related to drinking water and wastewater can be achieved. [Means for solving the problem]

[0015] Therefore, a method for treating wastewater to produce non-potable water, and a corresponding apparatus are provided, thereby enabling sufficiently good wastewater treatment and a reliable supply of non-potable water for the aforementioned uses by simple means.

[0016] The above-mentioned objective is achieved by the method according to the present invention as described in claim 1. In other words, the method according to the present invention comprises coarse filtration of wastewater, preferably aerobic bioremediation with sedimentation of particles and suspended matter, and subsequent ultrafiltration (preferably carried out by a membrane filter). Essential to the present invention is that the purification process is controlled in a closed loop according to the contamination of the wastewater, at least with respect to bio-purification and ultrafiltration.

[0017] According to the present invention, coarse debris such as hair is removed from the wastewater to be purified. This takes place within the coarse filter. The raw wastewater after rough filtration then undergoes preliminary sedimentation treatment, during which sediment such as dust and sand settles down. Preliminary bio-sedimentation is carried out. This preliminary bio-sedimentation is carried out before actual ultrafiltration. Ultrafiltration is understood as a specific form of membrane filtration.

[0018] Regarding membrane filtration, the lifespan of the membrane and the quality of membrane filtration are particularly important. According to the closed-loop control described in the claims, considering particularly the operation that does not burden the membrane filter, the load on the membrane filter is adjusted under closed-loop control according to the existing raw wastewater. After ultrafiltration, clean reclaimed water can be obtained.

[0019] Regarding the raw wastewater system according to the present invention, the above object is further achieved by the configuration of independent claim 16.

[0020] The raw wastewater system according to the present invention, from the perspective of the method according to the present invention described above, includes closed-loop control of the purification treatment according to the pollution of the raw wastewater, at least regarding bio-purification and ultrafiltration. The quality or composition of the raw wastewater is determined in the preliminary sedimentation tank and the raw wastewater tank. This is especially because water is transferred between these tanks by pumping and aerated in each tank. The pumping transfer speed, the aeration speed, and the residence time in each tank are continuously adjusted according to the treatment to ensure the least possible burden on the membrane filter arranged on the downstream side. What is important here is, on the one hand, to protect the membrane filter, and on the other hand, to supply sufficiently good quality of the treated raw wastewater, that is, sufficiently clean reclaimed water. [[ID=3']]

[0021] Preferably, water is supplied to the membrane filter by a self-priming pump, and this self-priming pump may be frequency-controlled. The closed-loop control circuit is configured based on the pressure and flow rate within the membrane filter.

[0022] Furthermore, in order to maintain excellent filtration performance during the implementation of this method, the membrane filter is periodically backwashed. The backwash water is sent back to the wastewater tank, where it is also reused for treatment. Therefore, no water loss occurs. Here again, closed-loop control comes into play.

[0023] It should be noted at this point that the method according to the present invention does not use any harmful chemicals that could affect or damage the environment. Instead, biodegradation occurs. The collected contaminant particles are removed as solid matter. Furthermore, these methods are optimized overall from an energy and economic standpoint through closed-loop control, with the primary objective being the production of sufficiently clean non-potable water.

[0024] Regarding closed-loop control, it is particularly important to emphasize that processing parameters are continuously acquired and recorded as needed. This acquisition and recording can be performed via the cloud on a central server. Unauthorized access to acquired data can be effectively prevented by conventional security measures.

[0025] The method according to the present invention employs advanced open-loop control technology, which makes it possible to individually control and monitor each step of the wastewater treatment process in a closed loop. The treatment process is carried out while correcting any changes in the inflow of wastewater using closed-loop control, and is continuously optimized according to the quality of the wastewater at each point in time. The operator of the wastewater system can access and operate this system online.

[0026] In open and / or closed-loop control, this wastewater system is equipped with a wide variety of sensors to obtain information about the state and quality of the water at each point in time. This allows for the measurement of various values, such as oxygen concentration, turbidity, total organic carbon, temperature including the surrounding area, spectral extinction coefficient, chromaticity, and filtrate volume, in both wastewater and recycled wastewater (e.g., non-potable water), and these values ​​are used for open / closed loop control of the treatment process. For this purpose, the sensors required are preferably installed in combination with each other, and at the bottom of each tank. The measurements obtained by the sensor system are suitable for use in AI applications, such as opening and closing loop control using AI-specific algorithms.

[0027] Downstream of the method and apparatus according to the present invention, further water treatment may be performed, which also includes a sensor system according to the above-mentioned viewpoint. This makes it possible to use non-potable water, for example, by using bacteria, as so-called "care water" for showering and bathing. Therefore, the aforementioned sensor system can also be used with non-potable water.

[0028] It is also conceivable to utilize wastewater and non-potable water for heat recovery, which can be done, for example, in front of or inside the wastewater recovery tank, or in front of or inside the non-potable water recovery tank. Ultimately, depending on the specific configuration of this sensor system, it may be possible to perform heat recovery either before or inside all recovery tanks.

[0029] Generally, heat is extracted via heat exchangers and, if necessary, heat pumps, allowing the existing heat to be utilized as efficiently as possible.

[0030] The heat obtained in this way can be supplied to, for example, a drinking water system, but for sanitary reasons, the piping system must be isolated. This necessity is based on legal requirements.

[0031] Regarding the degree of contamination and / or wear, it is also possible to monitor the membrane filter by, for example, checking the flow rate and / or water quality after filtration. This allows us to predict the lifespan of the membrane filter and indicate when it should be replaced.

[0032] Similarly, it is also conceivable to filter rainwater as needed using the method and apparatus according to the present invention. In this case, the bio-treatment process can be omitted. Through aeration and membrane filtration (ultrafiltration), even highly polluted rainwater can be treated to produce non-potable water that meets the required standards. This can be carried out independently of the treatment of wastewater.

[0033] To improve the overall efficiency of the system, a particularly advantageous approach is to alternately treat wastewater and rainwater; however, in this case, the membrane system needs to be operated alternately. Within the scope of this membrane system's expansion, a separate tank will be required to act as a rainwater buffer. A particular advantage here is that the device switches automatically or on demand to the appropriate water source (greasewater buffer or rainwater buffer).

[0034] Based on the above considerations, it is important that treated wastewater (non-potable water) not only conforms to the guidelines for bathing water, but also falls below the standards specified therein, and moreover, that this is achieved without the use of additional auxiliary measures such as UV disinfection. In the future, it is envisioned that water treated in this way will be used as "care water" for showers and baths. A legal amendment to permit this use is currently under consideration. [Brief explanation of the drawing]

[0035] [Figure 1] This figure shows a schematic configuration of a wastewater treatment system according to the present invention, which uses a method for treating wastewater to generate non-potable water according to the present invention. [Modes for carrying out the invention]

[0036] There are various possibilities for defining and developing the spirit of this invention. For this purpose, on the one hand, we refer to the claims dependent on claim 1, and on the other hand, we refer to the following description of embodiments of the present invention with reference to the drawings. In connection with the description of embodiments of the present invention with reference to the drawings, generally preferred configurations and developments relating to the spirit of the invention will also be described. The drawing shows a schematic configuration of a wastewater treatment system according to the present invention, which uses a method for treating wastewater to generate non-potable water, as a single figure. Closed-loop control as defined in the patent claims plays a crucial role.

[0037] The diagram schematically shows how wastewater from a shower, bathtub, washbasin, or kitchen is introduced through a coarse filter. However, a filter with an integrated overflow pipe may be used as the coarse filter.

[0038] From there, the wastewater after coarse filtration enters a wastewater recovery tank equipped with an aeration unit. The sediment is discharged into the drainage channel or disposed of by another method.

[0039] A batch pump is installed inside the wastewater tank. This batch pump circulates the wastewater after preliminary treatment by pumping, and sends it to, for example, a wastewater filtration tank. Furthermore, the wastewater filtration tank is also equipped with an aeration section. From there, the filtered wastewater enters the ultrafiltration station.

[0040] The ultrafiltration station is equipped with at least one membrane filter, which is periodically backwashed and cleaned, but the backwashing is performed at time intervals under closed-loop control. The wastewater used for backwashing, along with the dirt particles removed from the membrane filter, is sent to either a coarse filtration filter or a wastewater recovery tank for further treatment.

[0041] The wastewater obtained from the ultrafiltration station after purification, for example, water intended for use as non-potable water, is sent to a non-potable water storage tank equipped with a backwash pump.

[0042] The diagram shows that the water level in the non-potable water storage tank is monitored, and if the water level is too low, it is replenished with drinking water or, alternatively, rainwater (in accordance with the provisions of EN1717 Category 5 or national regulations). This ensures a constant supply of non-potable water. The non-potable water is then supplied via a pumping system to suitable users for purposes such as watering gardens, flushing toilets, washing clothes, and cleaning. It can handle all conceivable uses of non-potable water.

[0043] This method is implemented through closed-loop control using relevant processing parameters.

[0044] Further configurations of the apparatus according to the present invention are referred to in the general portion of the description and the appended claims to avoid repetition.

[0045] Finally, the embodiments of the apparatus according to the present invention are merely examples for illustrating the claimed technical idea and do not limit the technical idea to these embodiments. [Explanation of Symbols]

[0046] 1. Coarse filtration filter 2. Replenishment with drinking water 3. Wastewater batch pump 4... Channels 5. Wastewater recovery tank equipped with aeration section 6. Wastewater filtration tank with aeration section 7. Ultrafiltration Station 8. Non-potable water storage tank equipped with a backwash pump. 9. Pressure booster system

Claims

1. A method for treating wastewater in order to produce non-potable water, The purification process includes coarse filtration of the wastewater, preferably aerobic bio-purification with sedimentation of particles and suspended solids, and subsequent ultrafiltration, preferably ultrafiltration by a membrane filter. The purification process is characterized in that, with respect to at least the bio-purification and ultrafiltration, it is controlled in a closed loop according to the contamination of the wastewater.

2. The method according to claim 1, characterized in that the overflow pipe is an integrated filter used in the coarse filtration.

3. The method according to claim 1 or claim 2, characterized in that the wastewater after coarse filtration is aerated in a wastewater recovery tank and sent to another tank (wastewater tank) for bio-purification.

4. The method according to claim 3, characterized in that the bio-purification is carried out in the wastewater tank together with the addition of wastewater bacteria and aeration.

5. The wastewater after bio-purification is sent to an ultrafiltration station. The method according to claim 4, characterized in that the ultrafiltration is performed by a hollow fiber membrane filter.

6. The method according to any one of claims 1 to 5, characterized in that the wastewater generated by the purification process is stored in a wastewater tank and the wastewater is sent to one or more usable consumption destinations via a pressure booster system.

7. A backwash pump is provided inside or on the aforementioned miscellaneous water tank. The method according to any one of claims 1 to 6, characterized in that the backwash pump is used to backwash the membrane filter of the ultrafiltration station, and the backwash water is sent back to the wastewater to be purified.

8. The method according to any one of claims 1 to 7, characterized in that the closed-loop control is designed to treat wastewater in order to generate non-potable water, is performed only when actually needed, and thereby the pressure booster system is used efficiently.

9. The method according to any one of claims 1 to 8, characterized in that if a sufficient amount of non-potable water is not generated in the non-potable water tank, drinking water is supplied via a water level gauge under the closed-loop control.

10. The method according to any one of claims 1 to 9, characterized in that rainwater is the target of the purification treatment.

11. The method according to any one of claims 1 to 10, characterized in that at least the bio-purification and / or ultrafiltration, or their tanks, can be modularly expanded or supplemented by the respective equipment.

12. The method according to any one of claims 1 to 11, characterized in that the wastewater and / or at least partially treated wastewater / non-potable water are used for heat recovery.

13. The method according to any one of claims 1 to 12, characterized in that the closed-loop control affects the residence time of the wastewater at each station, the transfer speed by pumps between stations, and the aeration at each station in the purification treatment.

14. The method according to any one of claims 1 to 13, characterized in that the closed-loop control ensures that wastewater treatment is carried out without burdening the filter, by continuously adjusting the method parameters.

15. The method according to any one of claims 1 to 14, characterized in that the local network controlling the pressure booster system by the closed-loop control is connected to a central network via a LAN or WLAN connection.

16. The method according to any one of claims 1 to 15, characterized in that the closed-loop control can be operated or controlled by remote access via a mobile application or desktop, and optionally via sanitation technology.

17. An apparatus for treating wastewater in order to generate non-potable water, applicable to carrying out the method described in any one of claims 1 to 16.

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