Activated carbon chemical injection system and activated carbon chemical injection method

Abstract

To provide an activated carbon chemical injection system and an activated carbon chemical injection method that can easily and quickly measure an odor component generated from raw water, and that can stably suppress an odor generation from treated water for a long period of time while suppressing excessive injection of activated carbon.SOLUTION: There is provided an activated carbon chemical injection system including: an odor sensor 3 that detects an odor component emitted from raw water; an odor calculation unit 41 that calculates a type and a concentration of the odor component based on a detection result of the odor sensor 3; an activated carbon injection unit 25 that injects activated carbon into raw water to adsorb and remove the odor component; an injection rate calculation unit 42 that calculates an injection rate of the activated carbon to be injected into the raw water based on a calculation result of the odor component and water quality information of the raw water; and an injection control unit 43 that controls the injection rate of the activated carbon based on the calculation result of the injection rate.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a chemical injection system for activated carbon and a method for injecting chemicals into activated carbon.

Background Art

[0002] Conventionally, water purification treatment for making raw water such as river water, dam water, or lake water (hereinafter simply referred to as "raw water") into drinking water and the like is known. However, when cyanobacteria (blue-green algae), actinomycetes, mold, fungi, slime molds, etc. inhabit these raw waters, geosmin, which is a mold odor-causing substance, 2-methylisoborneol (2-MIB), and the like are generated. Therefore, the Waterworks Law sets a water quality standard that the concentration of 2-MIB or geosmin contained in the produced water is 10 ng / L or less, and proper treatment is required.

[0003] Normally, in raw water containing these substances, it is common to inject activated carbon for removal. Depending on the properties of the activated carbon, the injection equipment for activated carbon includes equipment for injecting wet powdered activated carbon (wet carbon), dry powdered activated carbon (dry carbon), and micronized activated carbon. Wet carbon contains about 50% moisture and is usually mixed with water to form a slurry liquid of a predetermined concentration (2.5 - 5%), which is injected by an injector, a pump, or the like. For dry carbon, for example, injection of dry activated carbon powder with a moisture content of 5% or less is carried out. As a device for injecting this dry activated carbon powder into a grit chamber, a well intake, etc., a powder supply device is known. The dry carbon is weighed as powder, mixed with water in a mixing layer to create a slurry liquid, and is similarly injected by an injector or a pump. Generally, activated carbon is injected through this powder supply device in accordance with the occurrence of mold odor.

[0004] As a powder supply device for dry carbon, for example, Japanese Patent Application Laid-Open No. 2007-69180 (Patent Document 1) proposes an example of a powder injection device provided with a powder injection mechanism that can maintain a rotor at an appropriate water depth for injecting powder even when the water level fluctuates, and can efficiently inject powder.

Prior Art Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2007-69180 [Overview of the project] [Problems that the invention aims to solve]

[0006] As mentioned above, the water quality standards for tap water stipulate that the concentrations of geosmin and 2-MIB should be 10 ng / L or less. However, in reality, some citizens who use tap water report that they can still detect an odor even at 10 ng / L, and therefore, lower concentrations are sometimes required. Some water treatment plants have voluntarily set lower concentrations, preferably 2 ng / L or less, for their management.

[0007] However, since it is impossible to control the substances that cause moldy odors when they flow in from river water or dam water, if these substances flow in at high concentrations, it becomes necessary to take measures to reduce their concentration within the water treatment plant. Normally, this is done by controlling the injection rate of activated carbon, but in order to control it more effectively, it is preferable to measure the concentrations of geosmin and 2-MIB, which cause moldy odors, quickly or in real time and take countermeasures.

[0008] However, in order to continuously measure the substances that cause these musty odors, it is necessary to use expensive analytical equipment such as gas chromatography-mass spectrometers (GC-MS) and to create a system to continuously or semi-conductively introduce the water to be treated into these devices. This is a considerable cost burden and is therefore not implemented in many water treatment plants.

[0009] Therefore, many water treatment plants employ a method of taking sample water at predetermined intervals and measuring it on a spot basis. However, the challenge with this method is that the data is discrete and not real-time, so the activated carbon injection rate must be determined by anticipating fluctuations in the concentrations of geosmin and 2-MIB. In reality, the injection rate may be excessive even when the concentrations of geosmin and 2-MIB are low. This leads to increased chemical costs and increased disposal costs for the amount of sludge generated.

[0010] In view of the above issues, the present invention provides an activated carbon chemical injection system and an activated carbon chemical injection method that can easily and quickly measure odor components generated from raw water and stably suppress the generation of odors from treated water over a long period of time while suppressing excessive injection of activated carbon. [Means for solving the problem]

[0011] In order to solve the above problems, the inventors of this invention conducted diligent research and found that it is useful to use an odor sensor that detects odor components emitted from raw water.

[0012] Based on the above findings, the present invention is, in one aspect, an activated carbon chemical injection system comprising: an odor sensor for detecting odor components emitted from raw water; an odor calculation unit for calculating the type and concentration of odor components based on the detection results of the odor sensor; an activated carbon injection unit for injecting activated carbon into the raw water to adsorb and remove odor components; an injection rate calculation unit for calculating the injection rate of activated carbon to be injected into the raw water based on the odor component calculation results and raw water quality information; and an injection control unit for controlling the injection rate of activated carbon based on the injection rate calculation results.

[0013] In one embodiment, the activated carbon chemical injection system according to the present invention further comprises a pre-treatment unit for performing pre-treatment to amplify odor components emitted from raw water.

[0014] In another embodiment of the chemical injection system according to the present invention, the pre-treatment section includes an oxidizing agent addition section for adding an oxidizing agent to raw water.

[0015] In another embodiment of the chemical injection system according to the present invention, the pretreatment unit uses one or more of the following methods on the raw water: ultrasonic treatment, reduced pressure treatment, jet impact, high pressure treatment, and ultraviolet irradiation treatment.

[0016] In yet another embodiment, the chemical injection system according to the present invention comprises an activated carbon injection unit which includes a storage tank for storing activated carbon, a mixing tank for mixing activated carbon and air to generate an activated carbon mixed fluid, a dispensing machine for dispensing a fixed amount of activated carbon from the storage tank and supplying it to the mixing tank, a dispensing control unit for controlling the dispensing amount of the dispensing machine based on an injection rate determined by an injection rate calculation unit, a transfer pipe for transferring the activated carbon mixed fluid generated in the mixing tank, and an injection mechanism connected to the transfer pipe for injecting activated carbon into raw water.

[0017] In yet another embodiment, the chemical injection system according to the present invention comprises an odor sensor comprising a plurality of adsorption membranes capable of interacting with specific odor components and detection units capable of detecting the adsorption state of odor components onto the adsorption membranes, and an odor calculation unit that identifies the type of odor component based on the detection pattern of the adsorption membrane detected by the detection unit and identification information of the detection pattern.

[0018] In yet another embodiment, the chemical injection system according to the present invention comprises at least one of geosmin or 2-methylisoborneol as an odor component.

[0019] In another aspect, the present invention is a chemical injection method for activated carbon, which includes introducing odor components emitted from raw water into an odor sensor, calculating the type and concentration of odor components based on the detection results of the odor sensor, calculating the injection rate of activated carbon to be injected into the raw water based on the calculation results of the odor components and the water quality information of the raw water, and injecting activated carbon into the raw water to the calculated injection rate. [Effects of the Invention]

[0020] According to the present invention, there can be provided an activated carbon chemical injection system and an activated carbon chemical injection method capable of simply and quickly measuring odor components generated from raw water and stably suppressing the generation of odor from treated water for a long period while suppressing excessive injection of activated carbon.

Brief Description of Drawings

[0021] [Figure 1] It is a schematic diagram showing an activated carbon chemical injection system according to an embodiment of the present invention. [Figure 2] It is a schematic diagram showing an example of an activated carbon injection part according to an embodiment of the present invention. [Figure 3] It is a schematic diagram showing a configuration example around a storage tank, a mixing tank, a cutter, and a transfer pipe included in an activated carbon injection part according to an embodiment of the present invention. [Figure 4] It is a block diagram showing a configuration example of an injection rate calculation part according to an embodiment of the present invention. [Figure 5] It is a flowchart showing an example of an activated carbon chemical injection method according to an embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0022] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. The embodiments shown below are examples of devices and methods for embodying the technical idea of this invention, and the technical idea of this invention does not specify the structure, arrangement, etc. of the components as the following.

[0023] (Activated Carbon Chemical Injection System) As shown in Figure 1, the chemical injection system 100 according to an embodiment of the present invention includes an odor sensor 3 for detecting odor components emitted from raw water, an odor calculation unit 41 for calculating the type and concentration of odor components based on the detection results of the odor sensor 3, an activated carbon injection unit 25 for injecting activated carbon into the raw water to adsorb and remove odor components, an injection rate calculation unit 42 for calculating the injection rate of activated carbon to be injected into the raw water based on the odor component calculation results and raw water quality information, and an injection control unit 43 for controlling the injection rate of activated carbon based on the determination result of the injection rate.

[0024] The following example describes a water treatment plant 200 in which activated carbon is injected into the raw water to remove odor components such as moldy odors within the water purification facility. However, it can of course be used in various other water treatment systems that also involve injecting activated carbon into the raw water.

[0025] The water treatment plant 200 includes, for example, an intake well 21, a rapid stirring tank 22, a flocculation tank 23, a sedimentation tank 24, an activated carbon injection unit 25, a rapid filtration tank 26, a water purification tank 27, and a distribution tank 28. The intake well 21 adjusts the amount and level of the raw water taken in. The rapid stirring tank 22 performs mixing treatment by rapidly stirring after injecting chemicals such as coagulants. The flocculation tank 23 injects a coagulant into the raw water, causes flocs to form, and coagulates the turbidity.

[0026] The sedimentation tank 24 allows coarse flocs formed in the floc formation tank 23 to settle by sedimentation separation. The rapid filtration tank 26 rapidly filters the supernatant water obtained from the sedimentation tank 24. The water purification tank 27 stores the purified water after it has undergone a predetermined sterilization treatment. The distribution reservoir 28 stores the purified water supplied from the water purification tank 27 and distributes it to various facilities such as homes, schools, and factories by gravity flow or other means.

[0027] Each piece of equipment in the water treatment plant 200 is equipped with measuring instruments (not shown). While not limited to the following, various measuring instruments may be provided to measure, for example, temperature, turbidity, clarity, color, pH, alkalinity, particulate matter count, TOC (total organic carbon), COD (chemical oxygen demand), ultraviolet absorbance, organic matter fractionation, etc.

[0028] The activated carbon injection unit 25 is equipment for injecting activated carbon to remove odor components emitted from raw water. The activated carbon injection unit 25 includes, for example, a storage tank 51 for storing activated carbon, a mixing tank 53 for mixing activated carbon and air to generate an activated carbon mixed fluid, a dispensing machine 52 for dispensing a fixed amount of activated carbon from the storage tank 51 and supplying it to the mixing tank 53, a dispensing control unit 54 for controlling the dispensing amount of the dispensing machine 52 based on the injection rate calculation unit 42 in Figure 1, a transfer pipe 55 for transferring the activated carbon mixed fluid generated in the mixing tank 53, and an injection mechanism 56 connected to the transfer pipe 55 for injecting activated carbon into the raw water.

[0029] The activated carbon stored in the storage tank 51 can be, for example, activated carbon produced by reacting coconut shells, coal, or charcoal with steam at 800-1000°C. By using activated carbon, it is possible to obtain activated carbon with many pores and a large specific surface area, typically 800-2500 m². 2 Activated carbon with a specific surface area of ​​approximately / g can be used. Odor components and organic matter that cause fouling, such as geosmin and 2-MIB, are adsorbed into the pores of the activated carbon, thereby removing them. Typically, for odor components with small molecular weights, such as moldy odors and trihalomethanes (disinfection by-products), activated carbon made from coconut shells with micropores of 2 nm or less in diameter is often used. On the other hand, for trihalomethane precursors such as humic substances with large molecular weights, activated carbon made from coal is often used. As the activated carbon stored in the storage tank 51, powdered charcoal with a particle size of approximately 0.15 mm or less is preferably used. The particle size of the activated carbon refers to the effective diameter (10% passage diameter) based on the activated carbon test method of JIS K1474.

[0030] As shown in Figure 3, the mixing tank 53 is provided with an air inlet 121 at the lower end of its side wall. An air inlet pipe 122 is connected to the air inlet 121 to allow air to flow into the mixing tank 53. The air introduced into the mixing tank 53 via the air inlet pipe 122 rises while moving from the bottom surface of the mixing tank 53 along the side wall, reverses direction at the ceiling surface of the mixing tank 53, and moves downward towards the side wall on the opposite side from the introduction side, thereby forming a swirling airflow in the vertical direction within the mixing tank 53, as shown by the dotted line in Figure 3. As a result, the activated carbon and the airflow in the mixing tank 53 are uniformly mixed, and an activated carbon mixed fluid is produced. One or more transfer pipes 55 are connected to the side wall of the mixing tank 53. Through these transfer pipes 55, the activated carbon mixed fluid produced in the mixing tank 53 is transferred to the injection mechanism 56 by pressurization or suction using air. In the injection mechanism 56, activated carbon is injected into the raw water.

[0031] The dispensing machine 52 is a mechanism for supplying powdered charcoal, such as dry activated carbon, stored in the storage tank 51 to the mixing tank 53 in fixed amounts. A dispensing control unit 54 is connected to the dispensing machine 52. Preferably, the dispensing control unit 54 controls, for example, the amount and interval of dispensing by the dispensing machine 52 so that activated carbon is injected into the raw water at the injection rate calculated by the injection rate calculation unit 42 in Figure 1. By controlling the injection rate with the dispensing control unit 54, dry charcoal can be weighed in powder form to create a slurry liquid, making it suitable for large-scale injection and enabling automatic addition.

[0032] As the odor sensor 3, a device called an odor sensor, olfactory sensor, or e-nose is preferably used, which has multiple sensor elements, each of which has an adsorption membrane that adsorbs odor substances in the air and a detection unit that detects the state of adsorption of odor substances to the adsorption membrane. Gas molecules are adsorbed onto each adsorption membrane of the odor sensor 3, and the detection unit electrically detects the state of adsorption, making it possible to distinguish odors. By using the odor sensor 3, it is possible to distinguish odors even when multiple odor components are mixed together.

[0033] The odor sensor 3 may be a dedicated detection device equipped with the aforementioned sensor elements for identifying multiple odors generated in the water treatment plant 200, or a small chip equipped with sensor elements may be incorporated into a portable device or mounted on an unmanned aerial vehicle such as a drone. This allows for simple and rapid measurement of odor components generated from raw water.

[0034] The adsorption film of each sensor element is formed from a thin film made of a polymeric substance such as resin. This thin film can contain, for example, at least one of inorganic acids, organic acids, or ionic liquids as a dopament. By changing the type and amount of dopament, the properties of the adsorption film can be changed, thereby obtaining an adsorption film that reacts specifically to a particular odor component. By arranging multiple adsorption films, for example, in a row or array, detecting the adsorption state of the films with a detection unit, and mapping this state, pattern information related to a specific odor can be obtained.

[0035] The detection unit is a device equipped with a signal conversion function that detects changes in the physical, chemical, or electrical properties of an adsorption film caused by the adsorption of odor substances onto the surface of the adsorption film, and outputs this detection data as, for example, an electrical signal. The information output by the detection unit can include electrical signals, light emission, changes in electrical resistance, changes in vibration frequency, etc. As for the detection unit, for example, a quartz crystal oscillator sensor (QCM), a surface acoustic wave sensor, a field-effect transistor (FET) sensor, a charge-coupled element sensor, a MOS field-effect transistor sensor, an organic conductive polymer sensor, an electrochemical sensor, etc., can be used and are selected according to the characteristics of the target odor component. By using such an odor sensor 3, the presence and concentration of odor components can be detected inexpensively, simply, quickly, and in real time, compared to conventional concentration measurement methods using GC-MS, etc., or by periodically sampling and measuring gas.

[0036] The detection result of the odor sensor 3 is output to the information processing device 4 connected to the odor sensor 3. The information processing device 4 can be configured with a general hardware configuration, and may include, for example, a processor, memory (e.g., RAM), storage medium (e.g., HDD, SSD), and a communication module. The information processing device 4 may function as a server device or as a client device, and may constitute a single hardware unit or be distributed across multiple hardware units.

[0037] As shown in Figure 1, the information processing device 4 includes, for example, an odor calculation unit 41, an injection rate calculation unit 42, and an injection control unit 43. The odor calculation unit 41 identifies the type and concentration of odor components based on the detection results of the odor sensor 3. For example, the odor calculation unit 41 identifies the type of odor component based on the detection patterns of multiple adsorption membranes detected by the detection unit of the odor sensor 3 and predetermined detection pattern identification information. The detection pattern identification information includes various detection pattern information for identifying various odor components contained in the raw water.

[0038] The various odor components contained in the raw water preferably include, for example, at least geosmin or 2-MIB, which cause moldy odors. Other odor components include ozone, ammonia, off-flavors, and oil. In addition to odors, turbidity, organic matter, trace amounts of oil, metals, etc., which may adversely affect water purification, may also be included as identification information in the detection pattern so that they can be detected by the odor sensor 3.

[0039] The identification information is pre-stored in a memory device (not shown) provided by the information processing device 4. The odor calculation unit 41 reads this identification information and compares it with the detection pattern of the adsorption film detected by the odor sensor 3 to identify the type of odor component. The concentration of the odor component can be calculated, for example, by detecting the detection sensitivity of the adsorption film and comparing it with the identification information.

[0040] The injection rate calculation unit 42 calculates the injection rate of activated carbon to be injected into the raw water based on the odor component calculation results by the odor calculation unit 41 and the water quality information of the raw water. For example, the injection rate calculation unit 42 can calculate the optimal injection rate by performing statistical analysis or simulation based on water quality information including odor component information of raw water treated in the water treatment plant 200 in the past, information on the injection rate of activated carbon injected in the past to remove those odor components, and the calculation results of the odor calculation unit 41.

[0041] Preferably, the injection rate calculation unit 42 predicts the injection rate of activated carbon to be injected into the raw water using a machine learning algorithm that employs a trained model to acquire predetermined explanatory variables and output a predetermined target variable. By using a machine learning algorithm, the injection rate calculation unit 42 can predict the injection rate with high accuracy, and activated carbon can be injected into the raw water at an injection rate that is more suitable for the properties of the raw water. As shown in Figure 4, the injection rate calculation unit 42 includes an information acquisition unit 421, a prediction unit 422, a database storage unit 423, and a trained model storage unit 424.

[0042] The information acquisition unit 421 is directly or indirectly connected to the aforementioned measuring instruments (not shown) provided in the water treatment plant 200, and acquires water quality data of treated water and raw water measured by the measuring instruments. The water quality data includes, for example, water temperature, pH, alkalinity, turbidity, and water volume data of the raw water and treated water from each facility in the water treatment plant 200, as well as at least one of the picoplankton concentration, algae concentration, and particulate matter concentration of the raw water. The water quality data is acquired before and after the injection of activated carbon. In addition to water quality data, the information acquisition unit 421 also acquires, for example, weather information (weather, temperature, humidity, rainfall, typhoon wind speed, central pressure, etc.).

[0043] For example, odor components such as moldy odors are known to be caused by the proliferation of phytoplankton, algae, and microorganisms in response to the influence of the surrounding environment, such as temperature. Therefore, by acquiring information on the temporal changes in meteorological information in addition to water quality data such as picoplankton concentration, algae concentration, and particulate matter concentration, the prediction unit 422, described later, can make more accurate predictions of the activated carbon injection rate. Furthermore, it is preferable that the information acquisition unit 421 acquires various parameters related to the operation of the water treatment plant 200, such as operating condition data including the amount of raw water flowing into each piece of equipment, stirring time, and stirring speed.

[0044] The prediction unit 422 acquires predetermined explanatory variables and predicts the injection rate of activated carbon to be injected into the raw water using a machine learning algorithm with a trained model capable of outputting the optimal injection rate of activated carbon to be injected into the raw water as the target variable. The explanatory variables include the results of odor component calculation by the odor calculation unit 41, raw water quality data acquired by the information acquisition unit 421, weather information, and operating condition data. When predicting moldy odor in the raw water, it is preferable that the explanatory variables acquired by the prediction unit 422 include, for example, at least one of the following: water temperature, pH, alkalinity, turbidity, water volume data of the water treatment plant 200, picoplankton concentration, algae concentration, and particulate matter concentration of the raw water. The prediction unit 422 can generate a plot diagram showing the relationship between the explanatory variables and the target variable. The prediction unit 422 may further convert the activated carbon injection rate into an amount to be added, etc.

[0045] The machine learning algorithm used by the prediction unit 422 is not particularly limited, but can be appropriately selected from various known analytical tools such as SVR (Support Vector Regression), PLS (Partial Least Squares), neural network methods (ANN, RNN), and random forest methods. In particular, for predicting the activated carbon injection rate, it is preferable to use LSTM or GRU among RNNs, and even more preferable to use LSTM, but it is not limited to these.

[0046] The database storage unit 423 can store various data acquired by the information acquisition unit 421. The database storage unit 423 may store past operational data of the water treatment plant 200, specifically, data including raw water data, operating condition data, and treated water treatment result data, or it may store a combination of operational data from multiple water treatment plants 200, or it may store a combination of operational data from at least one water treatment plant 200 and operational data from at least one other water treatment plant 200. The database storage unit 423 may also store, for example, water quality data measured by measuring instruments and activated carbon injection rates. There are no particular restrictions on the format in which the data is stored, and it is typically stored in a table format. The trained model storage unit 424 can store trained models created by the prediction unit 422, training data for constructing trained models, and various data necessary for creating trained models.

[0047] Based on the calculation result of the activated carbon injection rate by the injection rate calculation unit 42 in Figure 1, the injection control unit 43 outputs the calculation result of the injection rate to the activated carbon injection unit 25, which injects activated carbon into the raw water, and controls the injection rate of the activated carbon injection unit 25. In this embodiment, the activated carbon injection rate refers to the ratio of the activated carbon injection rate (mg) to the amount of raw water flowing in (L). The control of the injection rate depends on the method of the activated carbon injection unit 25, but is performed, for example, by controlling the valves, pumps, etc., provided in the activated carbon injection unit 25. This makes it possible to suppress the generation of odors from the treated water stably over a long period of time while suppressing the injection of excessive activated carbon.

[0048] Before the odor components of the raw water introduced into the odor sensor 3 are detected by the odor sensor 3, pretreatment is performed to amplify the odor components emitted from the raw water, thereby enabling more accurate detection of the odor components. For this reason, as shown in Figure 1, it is preferable that the activated carbon chemical injection system 100 according to the embodiment of the present invention further comprises a pretreatment unit 2 connected to the water intake pipe 1 for raw water.

[0049] The pre-processing unit 2 preferably includes a sample container for holding raw water. The flow rate of the raw water introduced into the sample container can be any desired rate. The raw water may be introduced continuously, in batches, or in semi-batches. Any device such as an air pump or blower can be used for introduction. It is preferable that odor components from the raw water diffuse into the gas phase in the sample container, and this gas phase is introduced into the odor sensor 3.

[0050] The pre-processing unit 2 may include, for example, an oxidizing agent addition unit (not shown) for adding an oxidizing agent to the raw water in the sample container, a heating unit (not shown) for heating the raw water in the sample container, and a pH adjustment unit (not shown) for adding a pH adjusting agent such as an alkaline agent to the raw water in the sample container. By heating with the heating unit and adjusting the pH with the pH adjustment unit, odor components generated from the raw water, especially moldy odors, are made more volatile, thereby increasing the detection concentration and enabling accurate measurements.

[0051] The pre-treatment unit 2 preferably includes an injection unit for an oxidizing agent such as sodium hypochlorite into the raw water in the sample container. The oxidizing agent injected by the injection unit preferably includes sodium hypochlorite, calcium hypochlorite (bleaching powder), chlorine dioxide, etc. Here, sodium hypochlorite will be used as an example. Adding sodium hypochlorite has the effect of decomposing cyanobacteria such as Formidium, Oscillatoria, and Anabaena, or actinomycetes, contained in the raw water. By decomposing these cyanobacteria or actinomycetes and eluting the geosmin or 2-MIB contained within them, which is then diffused into the gas phase in the sample container, odor components can be amplified more efficiently. This improves the detection accuracy of the odor sensor 3.

[0052] The method of addition can be any method. For example, the addition can be done according to the amount of raw water introduced, or it can be added each time the raw water in the sample container is replaced. The amount of oxidizing agent to be added can be selected at any concentration. In this embodiment, by adding 0.1 to 10 mg / L, or even 0.5 to 2 mg / L, to the raw water, the moldy odor in the raw water can be easily volatilized into the gas phase, thereby enabling more accurate measurement of odor components.

[0053] In particular, when detecting moldy odor as an odor component with the odor sensor 3, it is also preferable to decompose fine cyanobacteria or actinomycetes in the pre-treatment stage 2 using at least one of the following: ultrasonic treatment, reduced pressure treatment, jet impact, high pressure treatment, or ultraviolet irradiation treatment. It is also preferable to use this in combination with an oxidizing agent such as sodium hypochlorite.

[0054] According to the activated carbon chemical injection system 100 of the present invention, the type and concentration of odor components generated from raw water can be calculated using the odor sensor 3, thereby enabling easy and rapid measurement of odor components generated from raw water. Furthermore, the injection rate of activated carbon to be injected into the raw water can be determined by simulation or prediction using a machine learning algorithm, based on the measurement results of these odor components. As a result, even if there are rapid changes in the properties of the raw water, it becomes possible to stably suppress the generation of odors from treated water over a long period of time while suppressing excessive injection of activated carbon.

[0055] (Method of injecting chemicals into activated carbon) The activated carbon chemical injection method according to an embodiment of the present invention includes introducing odor components emitted from raw water into an odor sensor 3, calculating the type and concentration of odor components based on the detection results of the odor sensor 3, calculating the injection rate of activated carbon to be injected into the raw water based on the calculation results of the odor components and the water quality information of the raw water, and injecting activated carbon into the raw water to the calculated injection rate, and can be carried out, for example, according to the flowchart shown in Figure 5.

[0056] In step S1, raw water is sampled. In the example shown in Figure 1, the raw water stored in the intake well 21 is brought into the pre-treatment unit 2, which is equipped with a sampling container, via the water conduit 1. Note that the raw water sample may be obtained from any equipment other than the intake well 21. Next, in step S2, the pre-treatment unit 2 performs pre-treatment to amplify odor components emitted from the raw water, if necessary. For example, an oxidizing agent such as sodium hypochlorite is added at a rate of 0.1 to 10 mg / L to the raw water introduced into the sampling container.

[0057] In step S3, the gaseous components of the raw water are introduced into the odor sensor 3, and the odor sensor 3 is used to detect odor components generated from the raw water. Various types of sensors can be used as the odor sensor 3 as described above. In step S4, based on the detection results of the odor sensor 3, the odor calculation unit 41 in Figure 1 calculates the type and concentration of the odor components.

[0058] In step S5 of Figure 5, the injection rate calculation unit 42 of Figure 1 calculates the injection rate of activated carbon to be injected into the raw water based on the odor component calculation results and the raw water quality information. The injection rate calculation unit 42 calculates the injection rate of activated carbon by performing statistical analysis or simulation based on the odor component calculation results and past operational data, etc. Alternatively, the injection rate calculation unit 42 predicts the injection rate using a machine learning algorithm.

[0059] When predicting the injection rate using a machine learning algorithm, the injection rate calculation unit 42 receives data from the information acquisition unit 421 (Figure 4) to obtain water quality data and operating condition data for the raw water treated at the water treatment plant 200. The prediction unit 422 then receives the odor component calculation results from the odor calculation unit 41, raw water temperature, pH, alkalinity, turbidity, and water volume data acquired by the information acquisition unit 421, raw water picoplankton concentration, algae concentration, and particulate matter concentration water quality data, weather information, and operating condition data as explanatory variables, and inputs these into a trained model to predict the optimal injection rate of activated carbon. In step S5, the injection control unit 43 (Figure 1) receives the calculation or prediction result of the injection rate and, in step S6, outputs control information for the activated carbon injection rate to the activated carbon injection unit 25, and the activated carbon injection unit 25 performs activated carbon injection control.

[0060] As described above, according to the activated carbon chemical injection method of the embodiment of the present invention, the odor sensor 3 can easily and quickly detect the generation of odor components in the raw water, such as moldy odors. Based on this detection result, the optimal injection rate of activated carbon for removing odor components can be obtained by calculating the injection rate of activated carbon or predicting the injection rate using machine learning. As a result, odor components generated from the raw water can be measured easily and quickly, and the generation of odors from the treated water can be stably suppressed for a long period of time while suppressing the injection of excessive activated carbon.

[0061] Although the present invention has been described by the embodiments described above, the descriptions and drawings that constitute part of this disclosure should not be understood as limiting the invention. That is, this disclosure is not limited to the embodiments described above, and it goes without saying that the components can be combined and modified to embody the invention without departing from its essence.

[0062] For example, in this embodiment, a water purification plant was shown as the water treatment plant 200, but it can of course be used in various water treatment plants such as pure water production plants, wastewater treatment plants, sewage treatment plants, human waste treatment (sludge recycling) plants, leachate treatment plants, seawater desalination plants, and sludge treatment plants. Furthermore, although an example of detecting geosmin and 2-MIB, which cause moldy odors, was described, it is also possible to place odor sensors 3 that can detect various odor components generated in the water treatment plant 200. In addition, although this embodiment focuses on the injection rate of activated carbon, it can of course be applied to ozone concentration and other chemicals for removing moldy odors other than activated carbon. [Explanation of Symbols]

[0063] 1…Water conduit 2…Pre-treatment section 3...Sensor 4…Information Processing Devices 21…Waterfall well 22…Rapid stirring pond 23…Flocculation pond 24...Sedimentation tank 25...Activated carbon injection part 26…Rapid filtration pond 27…Water purification reservoir 28…Distribution reservoir 41... Odor calculation unit 42...Injection rate calculation section 43…Injection Control Unit 51…Storage tank 52...Cutting machine 53…Mixing tank 54...Cutting control section 55...Transfer pipe 56...Injection mechanism 100... Drug injection system 121...Air inlet 122... Air inlet pipe 200...Water treatment plant 421…Information acquisition department 422…Prediction section 423...Database storage unit 424...Storage for trained models

Claims

1. An odor sensor comprising multiple sensor elements, each having an adsorption membrane for adsorbing odor components emitted from raw water and a detection unit for detecting the adsorption state on the adsorption membrane, An odor calculation unit calculates the type of odor component based on the detection pattern of the adsorption membrane detected by the detection unit and the identification information of a predetermined detection pattern, detects the detection sensitivity of the adsorption membrane, and calculates the concentration of the odor component by comparing it with the identification information. An activated carbon injection unit for injecting activated carbon into the raw water to adsorb and remove odor components, An injection rate calculation unit calculates the injection rate of activated carbon to be injected into the raw water based on the calculation results of odor components and the water quality information of the raw water, Based on the calculation result of the injection rate, an injection control unit controls the injection rate of the activated carbon. A chemical injection system for activated carbon equipped with [a specific feature].

2. The activated carbon chemical injection system according to claim 1, further comprising a pre-treatment unit for performing pre-treatment to amplify the odor components emitted from the raw water.

3. The activated carbon chemical injection system according to claim 2, wherein the pretreatment unit includes an oxidizing agent addition unit for adding an oxidizing agent to the raw water.

4. The activated carbon chemical injection system according to claim 2, characterized in that the pretreatment unit uses one or more of the following means on the raw water: ultrasonic treatment, reduced pressure treatment, jet impact, high pressure treatment, and ultraviolet irradiation treatment.

5. The activated carbon injection section, A storage tank for storing the activated carbon, A mixing tank for mixing the activated carbon and air to produce an activated carbon mixed fluid, A dispensing machine that dispenses a quantitative amount of activated carbon from the storage tank and supplies it to the mixing tank, Based on the injection rate determined by the injection rate calculation unit, the cutting control unit controls the amount of material cut from the cutting machine, A transfer pipe for transferring the activated carbon mixed fluid generated in the mixing tank, An injection mechanism connected to the transfer pipe for injecting the activated carbon into the raw water, A chemical injection system for activated carbon according to any one of claims 1 to 4, comprising:

6. The activated carbon chemical injection system according to any one of claims 1 to 4, wherein the odor component comprises at least one of geosmin or 2-methylisoborneol.

7. Odor components emitted from raw water are introduced into an odor sensor equipped with multiple sensor elements, each of which comprises an adsorption membrane that adsorbs the odor components and a detection unit that detects the state of adsorption on the adsorption membrane. Based on the detection pattern of the adsorption film detected by the detection unit and the identification information of a predetermined detection pattern, the type of odor component is calculated. The detection sensitivity of the adsorption membrane is detected and compared with the identification information to calculate the concentration of the odor component. Based on the calculation results of the odor components and the water quality information of the raw water, the injection rate of activated carbon to be injected into the raw water is calculated. Inject activated carbon into the raw water so that the calculated injection rate is achieved. A method for injecting chemicals into activated carbon having the following characteristics.

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