Water treatment system

Abstract

This invention enhances the efficiency of decomposing organic pollutants while ensuring treatment safety by monitoring the abundance of aquatic plants in real time and optimizing the amount of hydrogen peroxide produced. [Solution] Aquatic plants that produce hydrogen peroxide used in the Fenton reaction are introduced into the water treatment facility. The water treatment system is equipped with a control device that performs control over the amount of aquatic plants. The control device is equipped with a data acquisition unit that acquires data. The control device is equipped with a control unit that performs control over the amount of aquatic plants. The data acquisition unit acquires data on the amount of aquatic plants present. The control unit performs control over the amount of aquatic plants so that the amount of aquatic plants present is kept within the range of the permissible amount of aquatic plants determined by the correlation between the amount of aquatic plants and the amount of hydrogen peroxide.

Description

Technical Field

[0001] The present invention relates to a water treatment system.

Background Art

[0002] Patent Document 1, which is the prior art, proposes a water treatment method for decomposing and removing refractory organic substances present in water by the Fenton reaction. In this method, aquatic plants are utilized, and hydrogen peroxide and iron ions present in the plant body react to generate hydroxyl radicals, which oxidize and decompose organic substances. Different from the existing Fenton reaction, in this method, since hydrogen peroxide in aquatic plants is utilized, excessive chemical addition is unnecessary, and low-cost and efficient water treatment becomes possible.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to further improve the problems of the prior art. Specifically, by controlling the amount of aquatic plants and adjusting the generation of hydrogen peroxide, the efficiency of the Fenton reaction is improved, and the treatment cost and the problem of chemical residue are reduced. Further, the present invention monitors the living amount of aquatic plants in real time and optimizes the generation amount of hydrogen peroxide, thereby enhancing the decomposition efficiency of organic pollutants while ensuring the safety of treatment.

Means for Solving the Problems

[0005] One aspect of the present invention is a water treatment system that decomposes organic pollutants that may be present in the water of a water treatment facility using hydroxyl radicals generated by the Fenton reaction. Aquatic plants that produce hydrogen peroxide used in the Fenton reaction are introduced into the water treatment facility. The water treatment system includes a control device that performs control over the amount of aquatic plants. The control device includes a data acquisition unit that acquires data. The control device includes a control unit that performs control over the amount of aquatic plants. The data acquisition unit acquires data on the amount of aquatic plants present. The control unit performs control over the amount of aquatic plants so that the amount of aquatic plants present is kept within the range of an acceptable amount of aquatic plants determined by the correlation between the amount of aquatic plants and the amount of hydrogen peroxide. [Effects of the Invention]

[0006] This invention utilizes aquatic plants to generate hydrogen peroxide and efficiently controls the Fenton reaction, thereby enabling the appropriate supply and management of the required amount of hydrogen peroxide. As a result, water treatment facilities can reduce the addition of unnecessary chemical substances, enabling efficient and low-cost water treatment. [Brief explanation of the drawing]

[0007] [Figure 1] This figure shows an example of a water treatment system 100. [Figure 2] This figure shows an example of the control device 120. [Figure 3] This figure shows an example of the processing performed by the control device 120 in the example shown in Figure 1 and Figure 2. [Figure 4] This figure shows an example of the correlation between the amount of aquatic plant AP and the amount of hydrogen peroxide. [Figure 5] This figure shows another example of the water treatment system 100. [Figure 6] This figure shows an example of the processing performed by the control device 120 in the example shown in Figure 5. [Figure 7] This figure shows an example of the processing performed by the control device 120 in the example shown in Figure 5. [Figure 8]This figure shows another example of the water treatment system 100. [Figure 9] This figure shows an example of the processing performed by the control device 120 in the example shown in Figure 8. [Figure 10] This figure shows another example of the water treatment system 100. [Figure 11] This figure shows an example of the processing performed by the control device 120 in the example shown in Figure 10. [Modes for carrying out the invention]

[0008] The present invention will be described below through embodiments, but these embodiments are not intended to limit the invention as defined in the claims. Furthermore, not all combinations of features described in the embodiments are necessarily essential to the solution of the invention. In addition, identical or similar parts may be given the same reference numeral in the drawings to omit redundant descriptions.

[0009] Figure 1 shows an example of a water treatment system 100. The water treatment system 100 is a system that decomposes organic contaminants that may be present in the water of a water treatment facility using hydroxyl radicals generated by the Fenton reaction.

[0010] Hydroxyl radicals are highly effective in breaking down organic pollutants in water treatment plants. Hydroxyl radicals are powerful oxidizing agents with the ability to break down organic pollutants into harmless substances.

[0011] Organic pollutants targeted for decomposition include, for example, pharmaceutical residues. Pharmaceuticals such as antibiotics, hormones, and painkillers discharged from hospitals and homes often remain in the water environment and can be decomposed by hydroxyl radicals. Hydroxyl radicals can decompose substances that are particularly difficult to remove by conventional biological treatment.

[0012] The organic pollutants to be decomposed include, for example, pesticides and herbicides. Agricultural wastewater contains a large amount of pesticides and herbicides. Pesticides and herbicides are regarded as a problem because they have an adverse impact on the environment. Hydroxyl radicals are effective in reducing the residual concentration in water by oxidizing and decomposing the molecular structures of pesticides and herbicides.

[0013] The organic pollutants to be decomposed include, for example, industrial chemicals such as dyes and surfactants. Factory wastewater may contain industrial chemicals such as dyes and surfactants. Hydroxyl radicals can efficiently decompose and mineralize complex organic compounds of industrial chemicals.

[0014] The organic pollutants to be decomposed include, for example, persistent organic pollutants such as perfluoroalkyl substances. Perfluoroalkyl substances are pollutants that are difficult to decompose and are difficult to treat in water treatment. However, in recent years, oxidative decomposition using hydroxyl radicals has attracted attention. Perfluoroalkyl substances require advanced treatment for complete decomposition. The scenarios where hydroxyl radicals enhance the decomposition efficiency are increasing.

[0015] The organic pollutants to be decomposed include, for example, phenols and benzene ring compounds. Phenols and benzene ring compounds contained in factory and urban wastewater are difficult to remove by normal treatment. Hydroxyl radicals are effective in improving water quality in order to promote decomposition.

[0016] As a method of using hydroxyl radicals in a water treatment facility, an advanced oxidation process is used. The advanced oxidation process generates hydroxyl radicals using ozone, ultraviolet rays, hydrogen peroxide, etc., and decomposes refractory organic pollutants. The water treatment system 100 generates hydroxyl radicals using hydrogen peroxide.

[0017] The water treatment system 100 is introduced into the water treatment facility of the water treatment solution. The water treatment solution is a series of processes and technologies for purifying the sewage discharged from households, factories, etc., and safely reusing it or discharging it into the natural environment. The water treatment solution prevents water pollution and promotes the reuse of precious water resources. The water treatment solution includes a primary sedimentation tank WT1, a reaction tank WT2, and a final sedimentation tank WT3. In addition, the water treatment solution includes at least one of the sewage reuse facility WT4 and the disinfection facility WT5.

[0018] The primary sedimentation tank WT1 is a facility installed at the initial stage of the sewage treatment process and is responsible for removing solids such as floating substances and sediment from the inflowing sewage. When the sewage enters the primary sedimentation tank WT1, the sediment sinks to the bottom under the action of gravity. The floating substances float to the surface. By removing the solids in this way, the primary sedimentation tank WT1 reduces the load on the subsequent reaction tank WT2.

[0019] The reaction tank WT2 is a facility for biodegrading organic substances and pollutants in sewage. In the reaction tank WT2, microorganisms are responsible for decomposing organic substances and treating them as sludge. Generally, in the reaction tank WT2, the activated sludge process is used, and the supply of oxygen promotes the activities of microorganisms. In the reaction tank WT2, as microorganisms grow by taking the organic substances in the sewage as food, the pollutants are decomposed and purified.

[0020] The final sedimentation tank WT3 is a facility for separating microorganisms and sludge from the sewage treated in the reaction tank WT2. The sewage passing through the reaction tank WT2 contains particles of activated sludge. In the final sedimentation tank WT3, these sludges settle, and the clarified water floats on the top. This supernatant water is sent to the next treatment process. Some of the settled sludge may be returned to the reaction tank WT2 and reused as microorganisms.

[0021] The WT4 wastewater recycling facility is designed to further treat water that has passed through the final sedimentation tank WT3, making it suitable for reuse. Depending on the intended reuse, the WT4 facility employs advanced treatment technologies such as membrane separation, activated carbon treatment, and reverse osmosis. Water treated in the WT4 facility can be reused for irrigation, industrial purposes, and even general-purpose water in urban areas.

[0022] The WT5 disinfection facility is designed to remove harmful microorganisms such as pathogens and viruses from wastewater in the final treatment stage. The WT5 facility primarily uses chlorine disinfection and ultraviolet disinfection to ensure safe water quality. By passing through the WT5 facility, the treated water becomes even safer, reducing the risks associated with discharge and reuse.

[0023] The primary sedimentation tank (WT1), reaction tank (WT2), final sedimentation tank (WT3), wastewater reuse facility (WT4), and disinfection facility (WT5) are the main treatment facilities in the water treatment solution. The water treatment solution utilizes different methods at each stage to treat wastewater efficiently and safely, minimizing its environmental impact.

[0024] In the example shown in Figure 1, the water treatment system 100 is installed in the final sedimentation tank WT3. The final sedimentation tank WT3 is an example of a water treatment facility.

[0025] By introducing the water treatment system 100 to the final sedimentation tank WT3, the system can further decompose organic pollutants that were not completely broken down in the reaction tank WT2, in addition to the microorganisms and sludge that are normally separated by sedimentation in the water that has passed through the reaction tank WT2. As a result, the water quality in the final treatment stage of the final sedimentation tank WT3 is further improved, and the quality of effluent and recycled water is enhanced.

[0026] Furthermore, by introducing the water treatment system 100 to the final sedimentation tank WT3, the hydroxyl radicals in WT3, possessing strong oxidizing power, can be expected to not only decompose organic matter but also kill bacteria and pathogens. This reduces the burden on the disinfection process in the water treatment solution and may even reduce the amount of disinfectant used. Since the water treatment system 100 uses hydrogen peroxide, it also offers an environmentally friendly disinfecting effect.

[0027] Furthermore, in the final sedimentation tank WT3, odors can normally be generated during the decomposition of settled organic matter by microbial activity. By introducing the water treatment system 100 to the final sedimentation tank WT3, the oxidative decomposition of organic matter by hydroxyl radicals in the final sedimentation tank WT3 makes it easier to remove odor-causing substances, leading to an improvement in the surrounding environment.

[0028] Furthermore, by introducing the water treatment system 100 to the final sedimentation tank WT3, the water treatment solution provides higher quality water suitable for reuse through additional decomposition treatment in the final sedimentation tank WT3. This increases the reliability of the reused water, as the water treatment solution can provide safe water free from harmful organic pollutants when reused for irrigation, industrial use, or general-purpose water in cities.

[0029] Water treatment system 100 generates hydroxyl radicals using the Fenton reaction. The Fenton reaction is a chemical reaction that generates hydroxyl radicals through the reaction of hydrogen peroxide and iron ions. The Fenton reaction is known as an oxidation reaction used for the decomposition of organic pollutants and water purification. In the Fenton reaction, iron ions decompose hydrogen peroxide, generating hydroxyl radicals and hydroxide ions.

[0030] The water treatment system 100 generates hydrogen peroxide using aquatic plant AP. Therefore, the water treatment system 100 introduces aquatic plant AP into the final sedimentation tank WT3. For example, floating aquatic plant AP such as water hyacinth or duckweed is introduced into the final sedimentation tank WT3.

[0031] The mechanism by which aquatic plant AP produces hydrogen peroxide is mainly related to the defense response and stress response such as oxidative stress of aquatic plant AP.

[0032] When aquatic plants (APs) are exposed to external stressors such as ultraviolet light, pollutants, and pathogens, a stress response occurs. During this stress response, highly reactive molecules called reactive oxygen species are produced. Hydrogen peroxide is one such molecule. Within the cells of aquatic plants (APs), there is an enzyme called superoxide dismutase. Superoxide dismutase uses oxygen to produce hydrogen peroxide.

[0033] Water treatment system 100 triggers a stress response by excessively increasing the amount of aquatic plant AP. Aquatic plant AP, which floats on the water surface, reproduces rapidly when environmental conditions are favorable. However, when the amount of aquatic plant AP becomes excessive, a stress response can be triggered in the AP itself and the entire ecosystem. Several factors are involved in this phenomenon.

[0034] For example, oxygen deficiency is involved in the phenomenon where an excessive increase in the amount of aquatic plants AP triggers a stress response. When aquatic plants AP completely cover the water surface, light transmission into the water is hindered, and photosynthesis in the water is suppressed. As a result, oxygen supply becomes insufficient, and the oxygen concentration in the water decreases, especially at night. This oxygen deficiency also triggers a stress response in the aquatic plants AP themselves. Therefore, oxygen deficiency is involved in the phenomenon where an excessive increase in the amount of aquatic plants AP triggers a stress response.

[0035] Furthermore, nutrient deficiencies are involved in the phenomenon where an excessive increase in the amount of aquatic plant AP triggers a stress response. When the amount of aquatic plant AP increases, competition for nutrients intensifies. When the amount of aquatic plant AP increases, individual aquatic plant APs cannot obtain sufficient nutrients due to the competition for limited nutrients, resulting in a deficiency of elements necessary for growth and causing stress. Therefore, nutrient deficiencies are involved in the phenomenon where an excessive increase in the amount of aquatic plant AP triggers a stress response.

[0036] Furthermore, waste accumulation is involved in the phenomenon where an excessive increase in the amount of aquatic plant AP triggers a stress response. When a large amount of aquatic plant AP is present in the same body of water, waste products accumulate in the water. The decomposition of these organic materials consumes oxygen, which can further worsen oxygen depletion. In addition, the organic acids and harmful chemicals produced by decomposition are stressors to aquatic plant AP. Therefore, waste accumulation is involved in the phenomenon where an excessive increase in the amount of aquatic plant AP triggers a stress response.

[0037] Thus, when the number of aquatic plants (AP) increases and becomes overcrowded, factors such as oxygen deficiency, nutrient deficiency, and waste accumulation interact with each other, putting stress on the aquatic plants (AP).

[0038] The water treatment system 100 includes a recovery device 110 and a control device 120. In the example shown in Figure 1, the water treatment system 100 also includes an imaging device 130.

[0039] The recovery device 110 is a device for recovering aquatic plants AP. The recovery device 110 is installed in the final sedimentation tank WT3. In the example shown in Figure 1, the recovery device 110 has the shape of a U-shaped waterway with an opening at the top in cross-sectional view, and is installed so that the position of the opening and the water level are at approximately the same height. The recovery device 110 is equipped with a watertight wall 111. The watertight wall 111 is a plate-shaped member that prevents water from the final sedimentation tank WT3 from flowing into the recovery device 110. The watertight wall 111 is provided to be movable vertically and is driven by a drive unit DU.

[0040] The drive unit DU is a device that moves the watertight wall 111 up and down. The drive unit DU is electrically or communicatively connected to the control device 120 and drives the watertight wall 111 according to control signals transmitted from the control device 120. The drive unit DU is configured, for example, using an electric motor or a hydraulic system.

[0041] The drive unit DU, which uses an electric motor, uses electrical energy to power the electric motor, which in turn moves the watertight wall 111 via gears, chains, or a screw mechanism. The drive unit DU, which uses an electric motor, precisely controls the watertight wall 111 by rotating the electric motor in the forward direction when raising it and in the reverse direction when lowering it. The drive unit DU, which uses an electric motor, is relatively easy to maintain and allows for quick adjustment of the position of the watertight wall 111.

[0042] The hydraulic drive unit DU moves the watertight wall 111 up and down via a hydraulic cylinder. Because the hydraulic drive unit DU can generate very strong force, it is suitable for driving large or heavy watertight walls 111. The hydraulic drive unit DU is applied, for example, when the flow rate is high or the size of the watertight wall 111 is large. Furthermore, because of the hydraulic system, the hydraulic drive unit DU allows for precise positional adjustment.

[0043] When the watertight wall 111 is lowered, the water from the final sedimentation tank WT3 flows into the recovery device 110. When the water from the final sedimentation tank WT3 flows into the recovery device 110, the aquatic plants AP flow into the recovery device 110 along with the water and are recovered.

[0044] On the other hand, when the watertight wall 111 is raised, the water in the final sedimentation tank WT3 is blocked by the watertight wall 111 and does not flow into the recovery device 110. When the water in the final sedimentation tank WT3 does not flow into the recovery device 110, the aquatic plants AP are blocked by the watertight wall 111 and are not recovered by the recovery device 110.

[0045] The control device 120 is a computer that performs control over the amount of aquatic plants AP. As described above, the control device 120 is electrically or communicatively connected to the drive device DU. The control device 120 is also electrically or communicatively connected to the output device OD. The output device OD is a device that presents the information handled by the control device 120 in a format that can be recognized by the user. The control device 120 is also electrically or communicatively connected to the imaging device 130.

[0046] The imaging device 130 is a device for imaging the water surface of the final sedimentation tank WT3. The imaging device 130 is positioned so that aquatic plants AP floating on the water surface of the final sedimentation tank WT3 are within its field of view. The imaging device 130 images the water surface of the final sedimentation tank WT3 when it receives a control signal from the control device 120 to instruct it to image. The imaging device 130 also images the water surface of the final sedimentation tank WT3 at predetermined time intervals, for example. The imaging device 130 also images the water surface of the final sedimentation tank WT3 at predetermined times, for example.

[0047] Figure 2 shows an example of the control device 120. The control device 120 includes a CPU 121, main memory 122, input / output interface 123, communication device 124, and storage 125.

[0048] The CPU 121 is a central device that performs program execution and calculation processing. Based on the installed water treatment program, the CPU 121 functions as a data acquisition unit SM1, an aquatic plant quantity estimation unit SM2, an aquatic plant quantity determination unit SM3, and a control unit SM4. The water treatment program is a computer program that enables the computer to function as the control device 120.

[0049] The data acquisition unit SM1 is a software module that acquires data.

[0050] The aquatic plant quantity estimation unit SM2 is a software module that estimates the amount of aquatic plants AP inhabiting the final sedimentation tank WT3.

[0051] The aquatic plant quantity determination unit SM3 is a software module that determines whether the amount of aquatic plants AP inhabiting the final sedimentation tank WT3 is within the permissible range.

[0052] The control unit SM4 is a software module that performs control over the amount of aquatic plant AP.

[0053] Main memory 122 is a storage device that temporarily holds programs and data.

[0054] The input / output interface 123 is a device for exchanging data between the CPU 121 and devices. In the example shown in Figure 2, the communication device 124, storage device 125, and output device OD are electrically connected to the input / output interface 123.

[0055] The communication device 124 connects the control device 120 to the network NW and enables data communication with other devices and the internet. In the example shown in Figure 2, the communication device 124 enables communication with the drive unit DU and the imaging device 130.

[0056] Storage 125 is a device for storing data and programs for a long period of time. For example, data acquired by the data acquisition unit SM1 is stored in storage 125.

[0057] Figure 3 shows an example of the processing performed by the control device 120 in the example shown in Figures 1 and 2.

[0058] The data acquisition unit SM1 of the control device 120 acquires image data of the water surface of the final sedimentation tank WT3 from the imaging device 130 (S101). In S101, the data acquisition unit SM1 acquires image data, for example, when the imaging device 130 images the water surface of the final sedimentation tank WT3. The data acquisition unit SM1 also acquires image data, for example, at predetermined time intervals. The data acquisition unit SM1 also acquires image data, for example, at predetermined times. The data acquisition unit SM1 also acquires image data, for example, when instructed by a user of the water treatment system 100. The data acquisition unit SM1 stores the image data acquired from the imaging device 130 in the storage 125.

[0059] The control device 120 executes the processes from S102 onward at any time. For example, the control device 120 executes the processes from S102 onward when it acquires image data from the imaging device 130. The control device 120 also executes the processes from S102 onward at predetermined time intervals, for example. The control device 120 also executes the processes from S102 onward at predetermined times, for example. The control device 120 also executes the processes from S102 onward when instructed by a user of the water treatment system 100, for example.

[0060] First, the aquatic plant quantity estimation unit SM2 of the control device 120 estimates the amount of aquatic plants AP inhabiting the final sedimentation tank WT3 using image data of the water surface of the final sedimentation tank WT3 (S102). Here, the aquatic plants AP floating on the water surface of the final sedimentation tank WT3 include both living and dead plants. Living aquatic plants AP, when actively metabolizing, increase the production and discharge of hydrogen peroxide. On the other hand, dead aquatic plants AP tend to decrease the production and discharge of hydrogen peroxide. Therefore, in S102, the aquatic plant quantity estimation unit SM2 analyzes the image data of the water surface of the final sedimentation tank WT3 to estimate the amount of aquatic plants AP inhabiting the final sedimentation tank WT3.

[0061] In step S102, the aquatic plant mass estimation unit SM2 first performs image normalization as a preprocessing step to improve the accuracy of image analysis, and adjusts the brightness and color tone of the image. The aquatic plant mass estimation unit SM2 also performs processing to minimize the effects of shadows and reflections.

[0062] Next, the aquatic plant mass estimation unit SM2 extracts features to distinguish between living aquatic plants AP and dead aquatic plants AP.

[0063] The aquatic plant quantity estimation unit SM2 extracts features such as color and texture to distinguish between living aquatic plant APs and dead aquatic plant APs. Living aquatic plant APs and dead aquatic plant APs generally differ in color and texture. For example, living aquatic plant APs are often green or bluish-green. On the other hand, dead aquatic plant APs tend to be brown or blackish. Therefore, the aquatic plant quantity estimation unit SM2 performs color space conversion, for example, from RGB to HSV, and extracts a specific color range.

[0064] Furthermore, the aquatic plant quantity estimation unit SM2 extracts features, such as shape characteristics, to distinguish between living aquatic plants AP and dead aquatic plants AP. There can be differences in shape between living aquatic plants AP and dead aquatic plants AP. For example, living aquatic plants AP tend to have clearly defined leaves and stems and a smooth shape. On the other hand, dead aquatic plants AP may have a distorted shape. Therefore, the aquatic plant quantity estimation unit SM2 extracts these shape characteristics using, for example, contour extraction or edge detection.

[0065] Next, the aquatic plant quantity estimation unit SM2 classifies aquatic plant APs into thriving and depleted aquatic plant APs by applying, for example, a machine learning model or a deep learning model. Users of the water treatment system 100 prepare, for example, images of thriving and depleted aquatic plant APs and construct a machine learning model or a deep learning model based on these. Then, users of the water treatment system 100 train the machine learning model or a deep learning model to classify thriving and depleted aquatic plant APs using, for example, extracted color, texture, and shape features. When using a deep learning model, features of aquatic plant APs can be automatically extracted, so more accurate classification can be expected.

[0066] Next, the aquatic plant quantity estimation unit SM2 extracts, for example, the region of the aquatic plant AP present in the image. The aquatic plant quantity estimation unit SM2 estimates the amount of the aquatic plant AP present by, for example, calculating the area of ​​this region.

[0067] Next, the aquatic plant mass estimation unit SM2 calculates the area ratio and density in order to quantify the estimated amount. Furthermore, the aquatic plant mass estimation unit SM2 can also evaluate the overall population by determining the ratio of the number of pixels corresponding to the aquatic plant AP to the total number of pixels in the image.

[0068] In this way, the aquatic plant quantity estimation unit SM2 can effectively estimate the amount of aquatic plants AP inhabiting the water surface through image analysis.

[0069] Furthermore, users of the water treatment system 100 can improve the accuracy of their machine learning or deep learning models by regularly conducting on-site observations and retraining with additional data to reduce misjudgments caused by reflections and shadows, for example.

[0070] Furthermore, users of the water treatment system 100 can, for example, statistically process estimated values ​​obtained from multiple images to verify their accuracy and reproducibility.

[0071] Next, the aquatic plant quantity determination unit SM3 of the control device 120 determines whether the amount of aquatic plants AP inhabiting the final sedimentation tank WT3 is within the permissible range (S103). Here, the permissible amount for the amount of aquatic plants AP is determined by the correlation between the amount of aquatic plants AP and the amount of hydrogen peroxide.

[0072] Figure 4 shows an example of the correlation between the amount of aquatic plant AP and the amount of hydrogen peroxide. The solid curve C1 shows the amount of aquatic plant AP as it changes with the number of days elapsed since the introduction of aquatic plant AP. The dashed curve C2 shows the amount of hydrogen peroxide as it changes with the number of days elapsed since the introduction of aquatic plant AP.

[0073] Here, organic pollutants are not sufficiently decomposed if there is insufficient hydroxyl radicals. Hydroxyl radicals are not sufficiently generated if there is insufficient hydrogen peroxide, which is used in the Fenton reaction. Hydrogen peroxide is not sufficiently generated if there is insufficient aquatic plant AP. Therefore, organic pollutants will not be sufficiently decomposed if there is insufficient aquatic plant AP present. Thus, the lower limit of the permissible amount LL is set based on the relationship between the amount of aquatic plant AP and the amount of organic pollutants in the water of the final sedimentation tank WT3. For example, the lower limit of the permissible amount LL represents the amount of aquatic plant AP present when the amount of organic pollutants in the water flowing into the final sedimentation tank WT3 and the amount of organic pollutants in the water flowing out of the final sedimentation tank WT3 are the same.

[0074] Furthermore, if aquatic plants (AP) increase excessively, they will die. Hydrogen peroxide is not produced sufficiently when aquatic plants (AP) die. Therefore, even if the amount of aquatic plants (AP) present increases excessively, organic pollutants will not be sufficiently decomposed. Thus, the upper limit of the permissible amount (UL) is set based on the relationship between the amount of aquatic plants (AP) and the amount of hydrogen peroxide. For example, the upper limit of the permissible amount (UL) indicates the amount of aquatic plants (AP) present when the amount of hydrogen peroxide is on a downward trend.

[0075] Returning to the explanation of Figure 3, in S103, the aquatic plant quantity determination unit SM3 determines, for example, whether the amount of aquatic plants AP inhabiting the final sedimentation tank WT3 is within the range from the lower limit LL to the upper limit UL of the permissible amount shown in Figure 4.

[0076] If the amount of aquatic plants AP present in S103 is within the permissible range (S103; YES), the control device 120 terminates the process shown in Figure 3.

[0077] If the amount of aquatic plants AP present in S103 is not within the permissible range (S103; NO), then the amount of aquatic plants AP present is either less than the lower limit LL of the permissible range or greater than the upper limit UL of the permissible range.

[0078] Therefore, if the amount of aquatic plants AP present is not within the permissible range (S103; NO), the aquatic plant quantity determination unit SM3 determines whether the amount of aquatic plants AP present exceeds the upper limit UL of the permissible range (S104). In S104, the aquatic plant quantity determination unit SM3 determines, for example, whether the amount of aquatic plants AP present in the final sedimentation tank WT3 exceeds the upper limit UL of the permissible range shown in Figure 4.

[0079] If the amount of aquatic plants AP present in S104 exceeds the upper limit UL of the permissible amount (S104; YES), the control unit SM4 executes control to recover the aquatic plants AP with the recovery device 110 (S105). In S105, the control unit SM4 transmits a first control signal to the drive unit DU instructing it to lower the watertight wall 111. Upon receiving the first control signal from the control device 120, the drive unit DU drives the watertight wall 111 to lower it. As described above, when the watertight wall 111 is lowered, the water from the final sedimentation tank WT3 flows into the recovery device 110. When the water from the final sedimentation tank WT3 flows into the recovery device 110, the aquatic plants AP flow into the recovery device 110 along with the water and are recovered. After a specific time has elapsed since transmitting the first control signal, the control unit SM4 transmits a second control signal to the drive unit DU instructing it to raise the watertight wall 111. When the drive unit DU receives a second control signal from the control device 120, it drives the watertight wall 111 to rise. As described above, when the watertight wall 111 is raised, the water in the final sedimentation tank WT3 is blocked by the watertight wall 111 and does not flow into the recovery device 110. When the water in the final sedimentation tank WT3 does not flow into the recovery device 110, the aquatic plants AP are blocked by the watertight wall 111 and are not recovered by the recovery device 110. Here, the amount of aquatic plants AP recovered can be adjusted by the time the watertight wall 111 is lowered. Therefore, the specific time between transmitting the first control signal and transmitting the second control signal is set so that the desired amount of aquatic plants AP is recovered.

[0080] Here, the amount of aquatic plants AP present is not within the permissible range (S103; NO), and if it does not exceed the upper limit UL of the permissible range (S104; NO), it is less than the lower limit LL of the permissible range.

[0081] Therefore, if the amount of aquatic plants AP present in S104 does not exceed the upper limit UL of the permissible amount, the control unit SM4 notifies that the amount of aquatic plants AP present is not within the permissible range (S106). In this case, in S106, the control unit SM4 notifies, for example, via the output device OD that the amount of aquatic plants AP present is less than the lower limit LL of the permissible amount. When a user of the water treatment system 100 is notified that the amount of aquatic plants AP present is less than the lower limit LL of the permissible amount, they add aquatic plants AP to the final sedimentation tank WT3.

[0082] On the other hand, even after the process in S105 has been executed, the control unit SM4 will execute the process in S106. If the process in S105 is being executed, the amount of aquatic plants AP present will exceed the upper limit UL of the permissible amount. In this case, in S106, the control unit SM4 will notify, for example, via the output device OD that the amount of aquatic plants AP present has exceeded the upper limit UL of the permissible amount.

[0083] In summary, the water treatment system 100 is a system that decomposes organic pollutants that may be present in the water of the final sedimentation tank WT3 using hydroxyl radicals generated by the Fenton reaction. Aquatic plant AP, which generates hydrogen peroxide used in the Fenton reaction, is introduced into the final sedimentation tank WT3. The water treatment system 100 includes a control device 120 that performs control over the amount of aquatic plant AP. The control device 120 includes a data acquisition unit SM1 that acquires data. The control device 120 includes a control unit SM4 that performs control over the amount of aquatic plant AP. The data acquisition unit SM1 acquires data on the amount of aquatic plant AP present. The control unit SM4 performs control over the amount of aquatic plant AP so that the amount of aquatic plant AP present is kept within the range of the permissible amount of aquatic plant AP determined by the correlation between the amount of aquatic plant AP and the amount of hydrogen peroxide.

[0084] With this configuration, the water treatment system 100 can appropriately supply and manage the required amount of hydrogen peroxide by generating hydrogen peroxide using aquatic plant AP and efficiently controlling the Fenton reaction. As a result, the addition of unnecessary chemicals in the final sedimentation tank WT3 is suppressed, enabling efficient and low-cost water treatment.

[0085] Furthermore, the water treatment system 100 is installed in the final sedimentation tank WT3 and includes a recovery device 110 for recovering aquatic plant AP. When the amount of aquatic plant AP present exceeds the upper limit UL of the permissible amount, the control unit SM4 executes control to recover the aquatic plant AP using the recovery device 110.

[0086] With this configuration, the water treatment system 100 can optimize the population size and maintain a stable response by introducing a recovery device 110 to avoid the overgrowth of aquatic plants AP.

[0087] Furthermore, the control unit SM4 performs control to notify the user that the amount of aquatic plants AP present is outside the acceptable range.

[0088] With this configuration, the water treatment system 100 can prevent excessive or insufficient hydrogen peroxide production by providing a function to notify of population levels exceeding acceptable limits, and can manage the Fenton reaction to proceed continuously under optimal conditions.

[0089] Furthermore, aquatic plants AP floating on the water surface are introduced into the final sedimentation tank WT3. The water treatment system 100 includes an imaging device 130 for imaging the water surface of the final sedimentation tank WT3. The data acquisition unit SM1 acquires image data of the water surface of the final sedimentation tank WT3 captured by the imaging device 130. The control unit SM4 analyzes the image and, based on the estimated amount of aquatic plants AP present, performs control over the amount of aquatic plants AP to keep the amount of aquatic plants AP within an acceptable range.

[0090] With this configuration, the water treatment system 100 monitors the abundance of aquatic plants AP through image analysis using water surface imaging, and by maintaining an appropriate amount, stabilizes the amount of hydrogen peroxide produced, enabling efficient water treatment.

[0091] Figure 5 shows another example of the water treatment system 100. Unlike the example shown in Figure 1, the water treatment system 100 in Figure 5 includes an organic pollutant measuring device 140.

[0092] The organic pollutant measuring device 140 is a device for measuring the amount of organic pollutants contained in the water of the final sedimentation tank WT3.

[0093] Users of the water treatment system 100 can, for example, use a total organic carbon meter as an organic pollutant measuring device 140 to measure the amount of organic pollutants in the water of the final sedimentation tank WT3. A total organic carbon meter is a device that measures the amount of organic pollutants in water as total organic carbon. Total organic carbon meters are widely used for industrial water management, monitoring of environmental water quality in rivers and lakes, and drinking water management. Since organic matter contains carbon, users of the water treatment system 100 can use the amount of organic matter present in the water as an indicator of organic pollution by estimating the carbon concentration. A total organic carbon meter oxidizes the organic matter in a water sample to convert it into carbon dioxide, and then detects the converted carbon dioxide to measure the amount of carbon in the sample.

[0094] Furthermore, users of the water treatment system 100 can, for example, use a liquid chromatograph-mass spectrometer as an organic pollutant measuring device 140 to measure the amount of organic pollutants contained in the water of the final sedimentation tank WT3. A liquid chromatograph-mass spectrometer is a device that analyzes individual components of organic pollutants contained in water and measures their concentrations with high precision. Liquid chromatograph-mass spectrometers are used in various fields, such as the analysis of tap water and groundwater, the detection of environmental pollutants, and the safety management of food and beverages. Liquid chromatograph-mass spectrometers are excellent at detecting specific chemical substances and are particularly suitable for the analysis of trace pollutants such as pesticides, pharmaceuticals, and chemicals. A liquid chromatograph-mass spectrometer separates compounds in a sample using liquid chromatography and measures the mass of each component with a mass spectrometer to identify each component and determine its concentration. Even when multiple organic pollutants are present, a liquid chromatograph-mass spectrometer can detect them as individual components.

[0095] Furthermore, users of the water treatment system 100 may, for example, use a gas chromatograph-mass spectrometer as an organic pollutant measuring device 140 to measure the amount of organic pollutants contained in the water of the final sedimentation tank WT3. A gas chromatograph-mass spectrometer is a device specifically designed for the detection of volatile organic compounds.

[0096] Furthermore, users of the water treatment system 100 may, for example, use a spectrophotometer as an organic pollutant measuring device 140 to measure the amount of organic pollutants contained in the water of the final sedimentation tank WT3. A spectrophotometer is a device for simply measuring indicators of organic pollutants, mainly using color and turbidity as indicators.

[0097] Figures 6 and 7 show an example of the processing performed by the control device 120 in the example shown in Figure 5.

[0098] In the example shown in Figure 6, if the amount of aquatic plant AP present in S104 exceeds the upper limit UL of the permissible amount (S104; YES), the control unit SM4 reads out data that can identify the amount of organic pollutants (S107). Users of the water treatment system 100 input data that can identify the amount of organic pollutants contained in the water of the final sedimentation tank WT3, measured using the organic pollutant measuring device 140, into the control device 120. When the data acquisition unit SM1 acquires the data input by the user of the water treatment system 100, it stores it in the storage 125. In S107, the control unit SM4 reads out the data stored in the storage 125, for example.

[0099] Next, the control unit SM4 determines whether the amount of organic pollutants in the water of the final sedimentation tank WT3 is less than the standard value (S108). In S108, the control unit SM4 determines whether the amount of organic pollutants identified by the data read in S107 is less than the standard value.

[0100] Standard values ​​for the amount of organic pollutants are set by, for example, scientifically evaluating the effects of organic pollutants on the human body and establishing safe concentrations for ingestion and contact. For example, standard values ​​are set by considering the possibility of carcinogenicity, toxicity, and long-term effects. Also, for example, standard values ​​are set with consideration for the impact on particularly susceptible people, such as children and the elderly.

[0101] Furthermore, standard values ​​for the amount of organic pollutants are set, for example, by evaluating the impact of organic pollutants on aquatic organisms and ecosystems. For example, standard values ​​are set based on the results of toxicity tests on fish and plants. Also, for example, standard values ​​are set taking into consideration the biodiversity and water purification capacity of the water body.

[0102] Furthermore, standard values ​​for the amount of organic pollutants are set within a range that can be measured using currently available analytical techniques, for example. This is because standard values ​​that cannot be detected are less effective.

[0103] Furthermore, standard values ​​for the amount of organic pollutants are set by referring to, for example, past pollution incidents, monitoring results, and existing domestic and international standards. For example, standard values ​​are set by referring to Japan's environmental standards and wastewater standards based on the Water Pollution Control Act. Alternatively, for example, standard values ​​are set by referring to WHO drinking water standards and regulatory values ​​in other countries.

[0104] Furthermore, standard values ​​for the amount of organic pollutants are set appropriately according to the use of the water, such as drinking water, agricultural water, and industrial water. For example, when used for drinking water, the standard value is set strictly, taking into account the direct impact on the human body. On the other hand, when used for industrial water, the standard value is set more leniently, according to the purpose of use.

[0105] Furthermore, the standard values ​​for the amount of organic pollutants are set to feasible values, taking into account the treatment capacity achievable by the water treatment system 100, because excessively strict standards could place an undue burden on operations.

[0106] Furthermore, standard values ​​for the amount of organic pollutants are set by, for example, comparing the increased treatment costs associated with stricter standards with the environmental protection benefits.

[0107] Furthermore, the standard values ​​for the amount of organic pollutants are set to be consistent with other regulatory values, such as industrial wastewater standards and river water quality standards.

[0108] Furthermore, standard values ​​for the amount of organic pollutants are set by taking into account the opinions of local residents, businesses, government agencies, and other stakeholders, and by striving to build social consensus.

[0109] If, in S108, the amount of organic pollutants in the water of the final sedimentation tank WT3 is greater than the standard value (S108; NO), the control unit SM4 executes the process in S105.

[0110] If, in S108, the amount of organic pollutants in the water of the final sedimentation tank WT3 is less than the standard value (S108; YES), the control unit SM4 does not perform the treatment in S105. If the control to recover aquatic plants AP in the recovery device 110 is not performed, the aquatic plants AP will grow beyond the upper limit of the permissible amount UL. In other words, the water treatment system 100 exceptionally allows aquatic plants AP to grow beyond the upper limit of the permissible amount UL when the amount of organic pollutants in the water of the final sedimentation tank WT3 is less than the standard value.

[0111] If the process in S105 is not executed, the control unit SM4 determines whether the conditions for recovering aquatic plant AP have been met (S109). For example, the conditions for recovering aquatic plant AP are when the amount of growing aquatic plant AP exceeds a specific amount greater than the upper limit UL of the allowable amount. Another example is when the aquatic plant AP has grown excessively and begins to wither and die.

[0112] If the conditions for recovering aquatic plant AP are met in S109 (S109; YES), the control unit SM4 executes control to recover the aquatic plant AP with the recovery device 110 (S110). In S110, the control unit SM4 transmits a first control signal to the drive unit DU instructing it to lower the watertight wall 111. Upon receiving the first control signal from the control device 120, the drive unit DU drives the watertight wall 111 to lower it. As described above, when the watertight wall 111 is lowered, the water from the final sedimentation tank WT3 flows into the recovery device 110. When the water from the final sedimentation tank WT3 flows into the recovery device 110, the aquatic plant AP flows into the recovery device 110 along with the water and is recovered. After a specific time has elapsed since transmitting the first control signal, the control unit SM4 transmits a second control signal to the drive unit DU instructing it to raise the watertight wall 111. Upon receiving the second control signal from the control device 120, the drive unit DU drives the watertight wall 111 to raise it. As mentioned above, when the watertight wall 111 is raised, the water in the final sedimentation tank WT3 is blocked by the watertight wall 111 and does not flow into the recovery device 110. When the water in the final sedimentation tank WT3 does not flow into the recovery device 110, the aquatic plants AP are blocked by the watertight wall 111 and are not recovered by the recovery device 110. Here, the amount of aquatic plants AP recovered can be adjusted by the time the watertight wall 111 is lowered. Therefore, the specific time between transmitting the first control signal and transmitting the second control signal is set so that the desired amount of aquatic plants AP is recovered.

[0113] Next, the control unit SM4 notifies via the output device OD that it has collected aquatic plants AP that have grown beyond the upper limit UL of the permissible quantity (S111).

[0114] If the conditions for recovering the aquatic plant AP are not met in S109 (S109; NO), the control unit SM4 terminates the process shown in Figure 7. In other words, if the conditions for recovering the aquatic plant AP are not met, the recovery device 110 does not execute the control to recover the aquatic plant AP, and the aquatic plant AP continues to grow and multiply. In other words, the aquatic plant AP continues to grow and multiply until the conditions for recovering the aquatic plant AP are met.

[0115] Users of the water treatment system 100 can, for example, utilize aquatic plant APs (Aquatic Plant Aquatic Plants) collected after their levels have continued to increase beyond the permissible limit UL as biofuels. Using aquatic plant APs as biofuels offers several advantages. For example, aquatic plant APs such as water hyacinths, water lilies, and reeds grow quickly, allowing for the production of large quantities of biofuels in a shorter time compared to other plants. Furthermore, aquatic plant APs absorb carbon dioxide during their growth process, making them a nearly carbon-neutral energy source.

[0116] Users of the water treatment system 100, in order to utilize aquatic plant AP as biofuel, for example, dry the aquatic plant AP to an appropriate moisture content, enzymatically decompose the cellulose within the aquatic plant AP, and ferment it to produce ethanol. Then, users of the water treatment system 100 can, for example, distill and purify the fermented ethanol and use it as fuel.

[0117] Furthermore, when users of the water treatment system 100 utilize aquatic plant AP as biofuel, for example, they dry the aquatic plant AP to an appropriate moisture content and perform anaerobic digestion to produce biogas such as methane and carbon dioxide. Then, users of the water treatment system 100 can, for example, purify the biogas to increase its energy density.

[0118] Users of the water treatment system 100 can, for example, supply biofuels such as ethanol or biogas as fuels that can be used in automobiles or power generation equipment.

[0119] In the examples shown in Figures 5 to 7 above, the water treatment system 100 includes an organic pollutant measuring device 140 for measuring the amount of organic pollutants contained in the water of the final sedimentation tank WT3. The data acquisition unit SM1 acquires identifiable data on the amount of organic pollutants measured by the organic pollutant measuring device 140. The control unit SM4 performs control over the amount of aquatic plants AP so that, if the amount of organic pollutants contained in the water of the final sedimentation tank WT3 is less than the standard value, it exceptionally allows the growth of aquatic plants AP beyond the upper limit of the permissible amount UL.

[0120] With this configuration, the water treatment system 100 exhibits various significant advantages compared to existing technologies.

[0121] For example, the water treatment system 100 can be made more flexible by allowing control to temporarily exceed the permissible growth limit of aquatic plants AP when the amount of organic pollutants is below the standard value. This allows the water treatment system 100 to increase the amount of hydrogen peroxide produced under specific conditions and make the Fenton reaction more efficient.

[0122] Furthermore, for example, the water treatment system 100 can maximize the reduction effect of organic pollutants by temporarily allowing the growth of aquatic plants AP, which would be considered excessive under normal standards. In addition, by avoiding the removal of unnecessary aquatic plants AP, the water treatment system 100 is expected to reduce environmental impact and management costs.

[0123] Furthermore, for example, the water treatment system 100 can improve its ability to maintain stable water quality even in environments with minor pollution by flexibly adjusting the amount of aquatic plant AP. This allows the water treatment system 100 to ensure a certain treatment capacity and appropriately manage the amount of hydrogen peroxide produced and the supply of hydroxyl radicals.

[0124] Furthermore, for example, the water treatment system 100 utilizes data from the organic pollutant measuring device 140 to dynamically adjust the system according to the amount of organic pollutants, thereby further enhancing the efficiency of the Fenton reaction. This allows the water treatment system 100 to optimize the use of energy and materials, enabling low-cost and effective water treatment.

[0125] Furthermore, for example, the water treatment system 100 has strong adaptability to changes in the external environment and water quality conditions because the system reacts dynamically according to the level of pollution. As a result, the water treatment system 100 contributes to the realization of sustainable water treatment.

[0126] Thus, with this configuration, the water treatment system 100 is superior to existing fixed aquatic plant AP management in that it allows for advanced control according to the status of organic pollutants, and greatly contributes to the overall efficiency of the system and the reduction of environmental impact.

[0127] Figure 8 shows another example of the water treatment system 100. Unlike the example shown in Figure 1, the water treatment system 100 in Figure 8 does not include an imaging device 130. Also, unlike the example shown in Figure 1, the water treatment system 100 in Figure 8 includes a hydrogen peroxide measuring device 150.

[0128] The hydrogen peroxide measuring device 150 is a device for measuring the amount of hydrogen peroxide produced by the aquatic plant AP.

[0129] Users of the water treatment system 100 can, for example, use a hydrogen peroxide measuring device 150 to measure the amount of hydrogen peroxide produced within the aquatic plant AP. The hydrogen peroxide measuring device 150, which measures the amount of hydrogen peroxide produced within the aquatic plant AP, includes, for example, a sample collection system, a chemical sensor, and a data processing unit. The sample collection system is a micromanagement tool, such as a microslice or cell disruptor, for extracting samples from the tissues and cells of the aquatic plant AP. The sample collection system obtains internal substances without damaging the structure of the aquatic plant AP. The chemical sensor is, for example, a sensor equipped with an electrochemical sensor or fluorescent probe that specifically reacts to hydrogen peroxide. The chemical sensor measures the concentration of hydrogen peroxide with high sensitivity based on oxidation-reduction reactions. The data processing unit is software that records and analyzes the measured values ​​in real time.

[0130] Furthermore, users of the water treatment system 100 can, for example, use a hydrogen peroxide measuring device 150 to measure the amount of hydrogen peroxide generated and discharged by aquatic plants AP. The hydrogen peroxide measuring device 150, which measures the amount of hydrogen peroxide generated and discharged by aquatic plants AP, comprises, for example, a sample collection system, a measuring cell, a sensor system, and a data recording device. The sample collection system is, for example, a pump and filter device for collecting a sample from the water in the final sedimentation tank WT3. The sample collection system has a sealed design to prevent contamination of the sample by external factors. The measuring cell contains, for example, a reagent that chemically reacts with hydrogen peroxide in the water. The measuring cell detects physical changes such as color, current, and fluorescence resulting from the reaction. The sensor system is, for example, a highly sensitive chemical sensor such as an electrode or fluorescence detector specifically for hydrogen peroxide. The sensor system can be combined with a water flow sensor to enable continuous measurement. The data recording device is a monitoring system for recording and analyzing measurement data in real time.

[0131] Figure 9 shows an example of the processing performed by the control device 120 in the example shown in Figure 8. In the example shown in Figure 9, unlike the example shown in Figure 1, the control device 120 performs the processes S201 and S202 instead of the processes S101 and S102.

[0132] The data acquisition unit SM1 of the control device 120 acquires data that can identify the amount of hydrogen peroxide (S201). In S201, the user of the water treatment system 100 inputs data that can identify the amount of hydrogen peroxide measured using the hydrogen peroxide measuring device 150 to the control device 120. The data acquisition unit SM1 acquires the data input by the user of the water treatment system 100.

[0133] The control device 120 executes the processes from S202 onward at any time. For example, the control device 120 executes the processes from S202 onward when it obtains data that allows it to identify the amount of hydrogen peroxide. The control device 120 also executes the processes from S202 onward at predetermined time intervals, for example. The control device 120 also executes the processes from S202 onward at predetermined times, for example. The control device 120 also executes the processes from S202 onward when instructed by a user of the water treatment system 100, for example.

[0134] First, the aquatic plant quantity estimation unit SM2 of the control device 120 estimates the amount of aquatic plants AP inhabiting the final sedimentation tank WT3 using data that can identify the amount of hydrogen peroxide (S202). As mentioned above, the aquatic plants AP floating on the surface of the final sedimentation tank WT3 include both living and dead plants. Living aquatic plants AP, when actively metabolizing, increase the amount of hydrogen peroxide produced and discharged. On the other hand, dead aquatic plants AP tend to decrease the production and discharge of hydrogen peroxide. Therefore, in S202, the aquatic plant quantity estimation unit SM2 uses this characteristic to estimate the amount of living aquatic plants AP.

[0135] The aquatic plant quantity estimation unit SM2 estimates the amount of surviving aquatic plants AP by, for example, referring to a reference value. The reference value is set by, for example, comparing the amount of hydrogen peroxide in surviving aquatic plants AP and dead aquatic plants AP. The reference value is set as a threshold that, for example, can be considered as surviving if it exceeds a certain amount.

[0136] In S202, the aquatic plant quantity estimation unit SM2 first compares the amount of hydrogen peroxide identified by the data obtained in S201 with a reference value. Then, if the amount of hydrogen peroxide is above the reference value, the aquatic plant AP is determined to be present.

[0137] Next, the aquatic plant quantity estimation unit SM2 estimates the proportion of aquatic plants AP present in the sample collected by the hydrogen peroxide measuring device 150, and calculates the total amount of aquatic plants AP present in the final sedimentation tank WT3.

[0138] In step S202, the aquatic plant quantity estimation unit SM2 improves estimation accuracy by, if necessary, using image analysis processing of image data of the water surface captured by the imaging device 130 shown in the example in Figure 1. Furthermore, in step S202, the aquatic plant quantity estimation unit SM2 improves estimation accuracy by, if necessary, using other indicators such as chlorophyll content and oxygen release.

[0139] After executing the process in S202, the control device 120 performs control on the amount of aquatic plant AP in the processes from S103 onward to keep the amount of aquatic plant AP within an acceptable range.

[0140] In the examples shown in Figures 8 and 9, the water treatment system 100 includes a hydrogen peroxide measuring device 150 for measuring the amount of hydrogen peroxide produced by aquatic plants AP. The data acquisition unit SM1 acquires identifiable data on the amount of hydrogen peroxide measured by the hydrogen peroxide measuring device 150. Based on the amount of hydrogen peroxide, the control unit SM4 performs control over the amount of aquatic plants AP to keep the amount of aquatic plants AP present within an acceptable range.

[0141] With this configuration, the water treatment system 100 can improve reaction efficiency by directly monitoring the amount of hydrogen peroxide produced by aquatic plants AP through the introduction of a hydrogen peroxide measuring device 150.

[0142] Figure 10 shows another example of the water treatment system 100. Unlike the example shown in Figure 1, the water treatment system 100 in Figure 10 does not include an imaging device 130. Also, unlike the example shown in Figure 1, the example in Figure 10 includes an ion measuring device 160.

[0143] The ion measuring device 160 is a device for measuring the amount of ions produced by the Fenton reaction.

[0144] Users of the water treatment system 100, for example, use a spectrophotometer as an ion measuring device 160 to measure the amount of trivalent iron ions produced by the Fenton reaction. Iron ions react with certain reagents, such as phenanthroline and ammonium thiocyanate, to form colored complexes. For example, the complex of trivalent iron ions with ammonium thiocyanate turns red, and the concentration can be quantified by measuring the absorbance. Users of the water treatment system 100, for example, add an appropriate amount of ammonium thiocyanate to the sample. Then, after the reaction, users of the water treatment system 100 measure the absorbance of the red color with a spectrophotometer. Then, users of the water treatment system 100 determine the amount of trivalent iron ions by concentration calculation.

[0145] Furthermore, users of the water treatment system 100 can, for example, use an inductively coupled plasma mass spectrometer as an ion measuring device 160 to measure the amount of trivalent iron ions produced by the Fenton reaction. An inductively coupled plasma mass spectrometer is a highly sensitive device for analyzing solutions containing iron ions. An inductively coupled plasma mass spectrometer can directly quantify the trivalent iron ions produced by the Fenton reaction.

[0146] Furthermore, users of the water treatment system 100 can, for example, use a pH meter as an ion measuring device 160 to measure the hydroxide ions produced by the Fenton reaction. The generation of hydroxide ions is accompanied by an increase in the pH of the solution. Users of the water treatment system 100 can, for example, indirectly estimate the amount of hydroxide ions by monitoring the pH of the reaction system in real time. Users of the water treatment system 100 can, for example, install a pH meter in the final sedimentation tank WT3. Then, users of the water treatment system 100 record the pH changes during the reaction. Then, users of the water treatment system 100 calculate the amount of hydroxide ions produced from the pH changes.

[0147] Furthermore, users of the water treatment system 100 can measure hydroxide ions produced by the Fenton reaction using, for example, an electrochemical measuring device such as an ion-selective electrode as an ion measuring device 160. Users of the water treatment system 100 can directly measure the hydroxide ion concentration in the water of the final sedimentation tank WT3 using, for example, an electrode with hydroxide ion selectivity. This method minimizes the influence of other ions.

[0148] Furthermore, users of the water treatment system 100 can, for example, use a titrator as an ion measuring device 160 to measure hydroxide ions produced by the Fenton reaction. This method measures the hydroxide ion concentration using acid-base titration. Users of the water treatment system 100 can, for example, titrate with a strong acid such as hydrochloric acid and calculate the hydroxide ion concentration from the amount of acid consumed.

[0149] Figure 11 shows an example of the processing of the control device 120 in the example shown in Figure 10. In the example shown in Figure 11, unlike the example shown in Figure 1, the control device 120 executes processes S301 and S302 instead of processes S101 and S102.

[0150] The data acquisition unit SM1 of the control device 120 acquires data that can identify the amount of ions generated by the Fenton reaction (S301). In S301, the user of the water treatment system 100 inputs data that can identify the amount of ions generated by the Fenton reaction, measured using the ion measuring device 160, into the control device 120. The data acquisition unit SM1 acquires the data input by the user of the water treatment system 100.

[0151] The control device 120 executes the processes from S302 onward at any time. For example, the control device 120 executes the processes from S302 onward when it acquires data that can identify the amount of ions. Also, the control device 120 executes the processes from S302 onward at predetermined time intervals, for example. Also, the control device 120 executes the processes from S302 onward at predetermined times, for example. Also, the control device 120 executes the processes from S302 onward when instructed by a user of the water treatment system 100, for example.

[0152] First, the aquatic plant quantity estimation unit SM2 of the control device 120 estimates the amount of aquatic plant AP inhabiting the final sedimentation tank WT3 using data that can identify the amount of ions produced by the Fenton reaction (S302). As mentioned above, the aquatic plant AP floating on the surface of the final sedimentation tank WT3 includes both living and dead plants. Living aquatic plant AP, when actively metabolizing, increases the production and discharge of hydrogen peroxide. On the other hand, dead aquatic plant AP tends to decrease the production and discharge of hydrogen peroxide. The amount of ions produced by the Fenton reaction increases in proportion to the increase in hydrogen peroxide production. The aquatic plant quantity estimation unit SM2 quantifies the amount of living aquatic plant AP by comparing the measured amount of ions with a standard curve that shows the relationship between the amount of ions produced by the Fenton reaction and the amount of aquatic plant AP.

[0153] In S302, the aquatic plant mass estimation unit SM2 improves estimation accuracy by, if necessary, using image analysis processing of image data of the water surface captured by the imaging device 130 shown in the example in Figure 1. Furthermore, in S302, the aquatic plant mass estimation unit SM2 improves estimation accuracy by, if necessary, using processing that allows for the identification of the amount of hydrogen peroxide measured by the hydrogen peroxide measuring device 150 shown in the example in Figure 8. Also, in S302, the aquatic plant mass estimation unit SM2 improves estimation accuracy by, if necessary, using other indicators such as chlorophyll content and oxygen release.

[0154] After executing the process in S302, the control device 120 performs control on the amount of aquatic plant AP in the processes from S103 onward to keep the amount of aquatic plant AP within an acceptable range.

[0155] In the examples shown in Figures 10 and 11, the water treatment system 100 includes an ion measuring device 160 for measuring the amount of ions produced by the Fenton reaction. The data acquisition unit SM1 acquires identifiable data on the amount of ions measured by the ion measuring device 160. The control unit SM4 performs control over the amount of aquatic plants AP to keep the amount of aquatic plants AP present within an acceptable range, based on the amount of ions.

[0156] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the embodiments. It will be apparent to those skilled in the art that various modifications or improvements can be made to the embodiments. Furthermore, to the extent that it is not technically contradictory, matters described for a particular embodiment can be applied to other embodiments. In addition, each component may have the same characteristics as other components that have the same name but different reference numerals. It will be clear from the claims that such modified or improved forms may also be included within the technical scope of the present invention.

[0157] In the example shown in the embodiment, the water treatment system 100 is introduced into the final sedimentation tank WT3. However, the water treatment system 100 can be introduced into the water treatment facility of the water treatment solution. The water treatment system 100 can be introduced into at least one of the following facilities of the water treatment solution: the primary sedimentation tank WT1, the reaction tank WT2, the final sedimentation tank WT3, the wastewater reuse facility WT4, and the disinfection facility WT5.

[0158] For example, the water treatment system 100 may be introduced into the primary sedimentation tank WT1.

[0159] By introducing the water treatment system 100 into the primary sedimentation tank WT1, the water treatment solution generates hydroxyl radicals in the primary sedimentation tank WT1, thereby breaking down organic pollutants in the wastewater in an early stage. In the water treatment solution, normally only solid matter settles in the primary sedimentation tank WT1 due to gravity, but by adding the decomposition reaction here, the amount of organic matter is reduced, and the load on the next treatment stage is significantly reduced.

[0160] Furthermore, by introducing the water treatment system 100 into the primary sedimentation tank WT1, the water treatment solution partially decomposes organic pollutants in the primary sedimentation tank WT1, reducing the load on microorganisms in the reaction tank WT2 and improving treatment efficiency. In the reaction tank WT2, the high concentrations of organic pollutants that burden microorganisms are reduced beforehand, allowing for smoother decomposition of organic matter by microorganisms and increasing overall treatment efficiency.

[0161] Furthermore, by introducing the water treatment system 100 to the primary sedimentation tank WT1, the amount of odor-causing substances and sludge generated in the primary sedimentation tank WT1 is suppressed through the decomposition of organic matter, making odor control within the facility more effective. In addition, since the amount of organic matter in the sediment decreases in the primary sedimentation tank WT1, the amount of sludge generated also decreases, easing the burden of sludge treatment.

[0162] Furthermore, by introducing the water treatment system 100 to the primary sedimentation tank WT1, the water treatment solution can reduce pollutants in the primary sedimentation tank WT1, thereby reducing the amount of chemicals used in subsequent treatment processes and lowering the total cost. In addition, the water treatment solution is expected to reduce the costs associated with sludge treatment and odor control, resulting in an overall reduction in operating costs.

[0163] For example, the water treatment system 100 may be introduced into the reaction tank WT2.

[0164] By introducing the water treatment system 100 to reaction tank WT2, the treatment capacity is further improved. Normally, biological treatment by microorganisms is carried out in reaction tank WT2, but by using the water treatment system 100 in conjunction, the treatment capacity is further enhanced. In reaction tank WT2, the strong oxidizing power of hydroxyl radicals makes even recalcitrant organic pollutants easier to decompose, converting them into a form that can be easily decomposed by microorganisms, thus efficiently reducing the total amount of organic matter.

[0165] Furthermore, by introducing the water treatment system 100 into reaction tank WT2, the hydroxyl radicals generated by the Fenton reaction in reaction tank WT2 facilitate the decomposition of organic matter, supporting microbial activity and improving the effectiveness of biological treatment. In reaction tank WT2, chemical substances and complex organic matter that are difficult for microorganisms to process are decomposed in advance, reducing the burden on microorganisms and enabling sustained and stable treatment.

[0166] Furthermore, by introducing the water treatment system 100 into reaction tank WT2, the decomposition reaction by hydroxyl radicals proceeds rapidly in reaction tank WT2, accelerating the decomposition of organic matter. As a result, the residence time in reaction tank WT2 is shortened in the water treatment solution, the treatment capacity is increased, and the efficiency of the facility is improved. In particular, the treatment capacity of the water treatment solution is improved during high load and peak times, expanding the overall capacity of wastewater treatment.

[0167] Furthermore, by introducing the water treatment system 100 into reaction tank WT2, the decomposition of organic matter progresses in reaction tank WT2, and the generation of malodorous components such as hydrogen sulfide and ammonia is suppressed. As a result, the surrounding environment of reaction tank WT2 is improved, and the working environment is made more comfortable. In addition, the water treatment solution reduces the level of sewage pollution, which also reduces the need for odor control in the treatment processes after reaction tank WT2.

[0168] Furthermore, by introducing the water treatment system 100 to reaction tank WT2, the amount of sludge is reduced in reaction tank WT2 due to the decomposition effect of the Fenton reaction, thereby lowering the costs of sludge treatment and sludge management. In addition, the microbial load in reaction tank WT2 is reduced, allowing for stable treatment, which in turn reduces the consumption of chemicals and energy, and lowers operating costs.

[0169] For example, the water treatment system 100 may be installed in the wastewater recycling facility WT4.

[0170] By introducing the water treatment system 100 to the WT4 wastewater recycling facility, the WT4 can decompose trace contaminants such as recalcitrant organic matter, chemical residues, and hormones that could not be broken down by conventional treatment. As a result, the quality of the final recycled water in the WT4 wastewater recycling facility is significantly improved, enabling the provision of safe and reliable water.

[0171] Furthermore, by introducing the water treatment system 100 to the WT4 wastewater recycling facility, the WT4 wastewater recycling facility can supply recycled water to a wider range of uses once high water quality is achieved through advanced treatment. For example, recycled water can be used for a variety of purposes, including irrigation, industrial water, and general-purpose water in cities, as well as cooling water, washing water, and even toilet flushing water. This water treatment solution promotes the efficient use of local water resources and contributes to the protection of water resources with limited supply.

[0172] Furthermore, by introducing the water treatment system 100 to the WT4 wastewater recycling facility, harmful organic substances and pathogenic microorganisms are removed from the WT4 wastewater recycling facility through the powerful oxidizing action of hydroxyl radicals, dramatically improving the safety of the recycled water. Particularly for uses such as non-potable water in cities where people come into direct contact, this reduces the risk of pathogens and enables the supply of safe and hygienic water.

[0173] Furthermore, by introducing the water treatment system 100 to the WT4 wastewater recycling facility, problems such as membrane fouling and scaling will be reduced, and the lifespan of the filters and membrane systems will be extended. As a result, the frequency of maintenance for the WT4 wastewater recycling facility will be reduced, ensuring the long-term stable operation of the facility.

[0174] For example, the water treatment system 100 may be installed in the disinfection equipment WT5.

[0175] By introducing the water treatment system 100 to the disinfection equipment WT5, the WT5 can effectively remove bacteria and viruses that are difficult to remove with existing disinfection methods such as chlorine and ultraviolet light. As a result, the WT5 can perform more advanced disinfection by adding treatment using hydroxyl radicals, improving the reliability of disinfection.

[0176] Furthermore, while existing disinfection methods often utilize chlorine-based chemicals, the introduction of the water treatment system 100 into the WT5 disinfection facility significantly reduces the amount of chlorine used. This not only lowers chemical costs but also minimizes the environmental impact of chemical residues, resulting in an ecologically sound disinfection process.

[0177] Furthermore, chlorine disinfection can produce harmful by-products such as trihalomethanes. By introducing the water treatment system 100 to the disinfection equipment WT5, the generation of such by-products is almost eliminated, making it a safe and healthy disinfection method. Suppressing by-products also contributes to the safety of recycled water and the quality of effluent.

[0178] Furthermore, by introducing the water treatment system 100 to the disinfection facility WT5, the WT5 disinfection facility will also remove odor-causing substances by decomposing organic matter through the powerful oxidizing action of hydroxyl radicals. As a result, the WT5 disinfection facility will reduce odors, especially in water before discharge and when it is reused, enabling water quality management that is considerate of the surrounding environment.

[0179] Furthermore, by introducing the water treatment system 100 to the disinfection facility WT5, the WT5 disinfection facility will more effectively remove residual organic matter and pathogens, further improving the quality of the discharged water. If the water released into the environment is clean, the disinfection facility WT5 will have less impact on the surrounding ecosystem and can maintain safe discharged water.

[0180] In the example shown in Figure 8, the water treatment system 100 does not have an organic pollutant measuring device 140. However, in the example shown in Figure 8, the water treatment system 100 may be equipped with an organic pollutant measuring device 140. In that case, the control device 120 performs control over the amount of aquatic plants AP to exceptionally exceed the upper limit UL of the permissible amount when the amount of organic pollutants is less than the standard value.

[0181] In the example shown in Figure 10, the water treatment system 100 does not have an organic pollutant measuring device 140. However, in the example shown in Figure 10, the water treatment system 100 may be equipped with an organic pollutant measuring device 140. In that case, the control device 120 performs control over the amount of aquatic plants AP so that, exceptionally, if the amount of organic pollutants is less than the standard value, the aquatic plants AP are grown beyond the upper limit UL of the permissible amount.

[0182] The execution order of operations, procedures, steps, and stages in the system described in the claims, specification, and drawings is not explicitly stated as "before" or "prior to." Furthermore, it should be noted that the execution order of each process can be any order, unless the output of a previous process is used in a later process. Even if the execution order of each process is described using terms such as "first" and "next" for convenience in relation to the operation flow in the claims, specification, and drawings, this does not mean that it is essential to perform them in that order. [Explanation of symbols]

[0183] 100 Water Treatment Systems 110 Recovery device 111 Watertight wall 120 Control device 121 CPU 122 Main Memory 123 Input / Output Interfaces 124 Communication equipment 125 storage 130 Imaging device 140 Organic pollutant measuring device 150 Hydrogen peroxide measuring device 160 Ion measuring device AP Aquatic plants C1 Solid curve C2 dashed curve DU drive unit LL lower limit NW (Network Communication Network) OD output device SM1 Data Acquisition Unit SM2 Aquatic Plant Volume Estimation Department SM3 Aquatic plant amount determination section SM4 Control Unit UL upper limit WT1 Primary sedimentation tank WT2 reaction vessel WT3 Final sedimentation tank WT4 Sewage reuse equipment WT5 disinfection equipment

Claims

1. A water treatment system that decomposes organic contaminants that may be present in the water of a water treatment facility by utilizing hydroxyl radicals generated by the Fenton reaction, The aforementioned water treatment facility is equipped with aquatic plants that produce hydrogen peroxide used in the Fenton reaction. It is equipped with a control device that performs control over the amount of aquatic plants, The control device is A data acquisition unit that acquires data, It comprises a control unit that performs control over the amount of aquatic plants, The data acquisition unit acquires data on the amount of aquatic plants present, The control unit performs control over the amount of aquatic plants so as to keep the amount of aquatic plants present within a range determined by the correlation between the amount of aquatic plants and the amount of hydrogen peroxide, in a water treatment system.

2. The aforementioned water treatment facility is equipped with a recovery device for collecting aquatic plants, The water treatment system according to claim 1, wherein the control unit executes a control to collect aquatic plants using the collection device when the amount of aquatic plants present exceeds the upper limit of the allowable amount.

3. The water treatment system according to claim 1, wherein the control unit performs control to notify that the amount of aquatic plants present is not within the allowable range when the amount of aquatic plants present is not within the allowable range.

4. The aforementioned water treatment facility has aquatic plants that float on the water surface introduced. The facility is equipped with an imaging device for imaging the water surface of the water treatment facility, The data acquisition unit acquires image data of the water surface of the water treatment facility captured by the imaging device, The water treatment system according to claim 1, wherein the control unit performs control over the amount of aquatic plants to keep the amount of aquatic plants present within the range of the allowable amount, based on the amount of aquatic plants present estimated by analyzing the image.

5. Equipped with a hydrogen peroxide measuring device for measuring the amount of hydrogen peroxide produced by aquatic plants, The data acquisition unit acquires data that can identify the amount of hydrogen peroxide measured by the hydrogen peroxide measuring device. The water treatment system according to claim 1, wherein the control unit performs control over the amount of aquatic plants based on the amount of hydrogen peroxide, so as to keep the amount of aquatic plants present within the range of the allowable amount.

6. Equipped with an ion measuring device for measuring the amount of ions produced by the Fenton reaction, The data acquisition unit acquires data that can identify the amount of ions measured by the ion measuring device. The water treatment system according to claim 1, wherein the control unit performs control over the amount of aquatic plants based on the amount of ions, so as to keep the amount of aquatic plants present within the range of the allowable amount.

7. The water treatment facility is equipped with an organic pollutant measuring device for measuring the amount of organic pollutants contained in the water, The data acquisition unit acquires data that can identify the amount of organic pollutants measured by the organic pollutant measuring device. The water treatment system according to claim 1, wherein the control unit performs control over the amount of aquatic plants so as to exceptionally allow the growth of aquatic plants to exceed the upper limit of the permissible amount when the amount of organic pollutants contained in the water of the water treatment facility is less than a standard value.

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