Measurement system and measurement method

Abstract

To improve the accuracy of total nitrogen measurement and total phosphorus measurement.SOLUTION: A measurement system according to an embodiment includes a measurement device to which a sample is supplied and which electrically performs oxidation treatment on the sample using a first electrode, a measurement device to which the oxidation-treated sample is supplied and which electrochemically performs total nitrogen measurement or total phosphorus measurement on the sample using a second electrode, a cleaning device to which the measured second electrode is moved and which cleans the second electrode, a storage device to which the cleaned second electrode is moved and which stores the second electrode, and a transporter which moves the second electrode to the measurement device, the cleaning device, and the storage device in this order.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION Embodiments of the present invention relate to a measurement system and method for measuring total nitrogen and total phosphorus. [Background technology]

[0002] The concentrations of total nitrogen and total phosphorus in a solution are generally measured by absorptiometry (ultraviolet oxidation method). Absorptiometry has difficulty measuring substances at lower concentrations. Electrochemical measurement is a method that can measure substances at lower concentrations than absorptiometry. Electrochemical measurement can measure substances at very low concentrations, making it a suitable measurement method for obtaining more accurate information.

[0003] For example, at sewage treatment plants, total nitrogen and total phosphorus in sewage are measured. However, unlike laboratories, the measurement environment at sewage treatment plants can be poor. When electrochemical measurements are performed at sewage treatment plants, the accuracy of the measurements is reduced due to electrode contamination, water flow, and electrode deterioration. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4691266 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-83083 [Patent Document 3] Japanese Patent Application Laid-Open No. 2009-294063 [Patent Document 4] Japanese Patent Application Laid-Open No. 2004-184132 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a measurement system and a measurement method that can improve the accuracy of total nitrogen and total phosphorus measurements. [Means for solving the problem]

[0006] The measurement system according to the embodiment comprises a pretreatment device to which a sample is supplied and which performs an electrical oxidation treatment on the sample using a first electrode; a measurement device to which the oxidized sample is supplied and which performs electrochemical total nitrogen or total phosphorus measurement on the sample using a second electrode; a cleaning device to which the second electrode is moved after the measurement and which cleans the second electrode; a storage device to which the second electrode is moved after the cleaning and which stores the second electrode; and a transporter that moves the second electrode from the measurement device to the cleaning device and then to the storage device in that order. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic configuration diagram of a measurement system according to an embodiment. [Figure 2] FIG. 2 is a perspective view illustrating the configuration of the pretreatment device. [Figure 3] FIG. 3 is a perspective view illustrating the configuration of the measurement module. [Figure 4] FIG. 4 is a diagram illustrating the electrodes and their surrounding structure. [Figure 5] FIG. 5 is a perspective view illustrating the configuration of the flush water tank. [Figure 6] FIG. 6 is a flowchart illustrating the operation of the measurement system. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments will be described with reference to the drawings. However, the drawings are schematic or conceptual, and the dimensions and proportions of each drawing are not necessarily the same as those of the actual drawing. Furthermore, even when the same parts are shown in different drawings, the dimensional relationships and proportions may be different. In particular, the following embodiments are illustrative of devices and methods for embodying the technical concept of the present invention, and the shape, structure, arrangement, etc. of the components do not specify the technical concept of the present invention. In the following description, elements having the same function and configuration are designated by the same reference numerals, and redundant description will be omitted.

[0009] [1] Configuration of measurement system 1 1 is a schematic diagram of a measurement system 1 according to an embodiment. The measurement system 1 is a system for measuring total nitrogen and total phosphorus in a sample.

[0010] Total nitrogen (TN) refers to the total amount of nitrogen compounds contained in water, and consists of inorganic nitrogen (IN) and organic nitrogen (ON). Inorganic nitrogen consists of ammonia nitrogen (NH4-N), nitrite nitrogen (NO2-N), and nitrate nitrogen (NO3-N). Total phosphorus (TP) refers to the total amount of phosphorus compounds contained in water, and consists of inorganic phosphorus and organic phosphorus.

[0011] The measurement system 1 includes a pump 10, a pretreatment device 20, a measurement module 30, a cleaning water tank 40, a pump 41, and a control device 50.

[0012] A sample S is supplied to the pump 10. The sample S is a solution to be measured, such as treated water from a sewage treatment plant or industrial wastewater. The pump 10 is connected to a pretreatment device 20. The pump 10 has the function of transporting the sample S to the pretreatment device 20.

[0013] The pretreatment device 20 is a device that performs pretreatment on the sample S. Pretreatment is a process that converts nitrogen compounds or phosphorus compounds in the sample S into measurement substances prior to measuring total nitrogen and total phosphorus. In this embodiment, the pretreatment is performed using an electrochemical reaction. The pretreatment device 20 has a structure that allows the sample S to be stored. An electrode 21 for the electrochemical reaction is disposed in the pretreatment device 20. The electrode 21 has, for example, a cylindrical shape. The electrode 21 is supported by a support member 22 disposed above the pretreatment device 20. The sample S that has been pretreated by the pretreatment device 20 is supplied to the measurement module 30 (specifically, the measurement device 33 described below).

[0014] The measurement module 30 is an apparatus for measuring total nitrogen and total phosphorus in the sample S. In this embodiment, the total nitrogen and total phosphorus measurements are performed using electrochemical reactions. An electrode 31-1 for measuring total nitrogen and an electrode 31-2 for measuring total phosphorus are disposed in the measurement module 30. In this embodiment, when there is no need to distinguish between the electrode 31-1 and the electrode 31-2, they will be referred to as electrode 31 in the following description.

[0015] The measurement module 30 includes a measurement device that measures total nitrogen and total phosphorus using electrodes 31-1 and 31-2, a cleaning device that cleans the electrodes 31-1 and 31-2, and a storage device that dries and stores the electrodes 31-1 and 31-2. The electrodes 31-1 and 31-2 are supported by a transporter 32 disposed above the measurement module 30 and can be moved between the devices.

[0016] The cleaning water tank 40 stores cleaning water supplied from the measurement module 30. In this embodiment, the cleaning water is reused by circulating between the measurement module 30 and the cleaning water tank 40. The pump 41 has the function of transferring the cleaning water in the cleaning water tank 40 to the measurement module 30.

[0017] The control device 50 comprehensively controls the operation of the entire measurement system 1. The control device 50 includes one or more processors, such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), and a memory unit that stores programs executed by the processor. The control device 50 also includes a power supply circuit, and supplies voltage to the pre-processing electrodes and the measurement electrodes via wiring (not shown). The control device 50 also performs pre-processing and measurement processes. The control device 50 also controls the operations of the pumps 10, 41, and the transporter 32.

[0018] [1-1] Configuration of pre-processing device 20 Next, a specific configuration of the pre-treatment device 20 will be described. FIG.

[0019] The pretreatment device 20 is configured as, for example, a cylindrical container. The pretreatment device 20 has a hemispherical bottom. By configuring the bottom of the pretreatment device 20 to be hemispherical, the fluidity of the sample S can be improved.

[0020] The pretreatment device 20 has one or more rotors 23 at its bottom. The rotors 23 are configured so that a propeller rotates, and have the function of stirring the sample S. The operation of the rotors 23 is controlled by the control device 50.

[0021] The pretreatment device 20 configured in this manner can agitate the sample S and mix the sample S in various directions, thereby accelerating the electrochemical reaction using the electrodes 21 in the pretreatment.

[0022] [1-2] Configuration of measurement module 30 Next, a specific configuration of the measurement module 30 will be described. Fig. 3 is a perspective view illustrating the configuration of the measurement module 30. The measurement module 30 includes a measurement device 33, a cleaning device 34, and a storage device 35.

[0023] The measuring device 33 is a device for measuring total nitrogen and total phosphorus of a sample S. The measuring device 33 has a structure capable of storing the sample S for measuring total nitrogen and total phosphorus. The measuring device 33 is composed of, for example, a cylindrical container. The measuring device 33 is supplied with the sample S from the pretreatment device 20. An electrode 31 (electrode 31-1 for measuring total nitrogen or electrode 31-2 for measuring total phosphorus) is arranged in the measuring device 33.

[0024] A valve 36 is connected to the bottom of the measuring device 33 via a flow path. The sample S measured in the measuring device 33 is discharged as waste liquid using the valve 36. The operation of the valve 36 is controlled by the control device 50.

[0025] The cleaning device 34 is a device for cleaning the electrode 31 used in the measurement. The cleaning device 34 has a structure capable of storing cleaning water. The cleaning device 34 is composed of, for example, a cylindrical container. The electrode 31 used in the measurement is placed in the cleaning device 34. Cleaning water is supplied to the cleaning device 34 from a cleaning water tank 40. The electrode 31 placed in the cleaning device 34 is cleaned using the cleaning water. The cleaning water stored in the cleaning device 34 is returned to the cleaning water tank 40.

[0026] The storage device 35 is a device for storing the cleaned electrode 31. The storage device 35 is formed, for example, of a cylindrical container. The storage device 35 allows the electrode 31 to air dry. The storage device 35 may store a storage solution. In this modification, the electrode 31 is stored immersed in the storage solution stored in the storage device 35. The storage device 35 stores the electrode 31 until the next measurement is performed.

[0027] The transporter 32 moves the electrode 31 to the measuring device 33, the cleaning device 34, and the storage device 35 in that order, and circulates the electrode 31 among the measuring device 33, the cleaning device 34, and the storage device 35. The transporter 32 moves the electrode 31 at predetermined time intervals, for example.

[0028] 4 is a diagram illustrating the electrode 31 and its surrounding structure. In addition to the electrode 31, the measurement system 1 includes a cleaning line 61, an airline 62, and a wave protection pipe 63.

[0029] The electrode 31 is an electrode for measuring total nitrogen or total phosphorus in the sample S. The electrode 31 has, for example, a cylindrical shape.

[0030] The cleaning line 61 is attached to the upper part and side of the electrode 31, and is arranged along the extension direction of the electrode 31. Cleaning water is supplied to the cleaning line 61 from the cleaning water tank 40. The cleaning line 61 supplies cleaning water to the electrode 31. The cleaning line 61 is driven when the electrode 31 is placed in the cleaning device 34.

[0031] The airline 62 is attached to the upper part and side of the electrode 31, and is arranged along the extension direction of the electrode 31. Air is supplied to the airline 62 from an air pump 64. The operation of the air pump 64 is controlled by the control device 50. The airline 62 supplies air to the electrode 31. The airline 62 is driven when the electrode 31 is placed in the storage device 35.

[0032] The wave protection tube 63 has, for example, a cylindrical shape. The wave protection tube 63 is configured to surround the side surface of the electrode 31. The wave protection tube 63 has the function of suppressing movement of the sample around the electrode 31. In electrochemical measurements, if the sample to be measured is moving, noise is generated, which may result in inaccurate measurements. By providing the wave protection tube 63, it is possible to improve measurement accuracy.

[0033] [1-3] Configuration of flush water tank 40 Next, we will explain the specific configuration of the flush water tank 40. Figure 5 is a perspective view that explains the configuration of the flush water tank 40.

[0034] The flush water tank 40 has a structure capable of storing flush water. The flush water tank 40 is connected to the bottom of the cleaning device 34 using a flow path 42. The flow path 42 allows the flush water accumulated in the cleaning device 34 to flow into the flush water tank 40. The flow path 42 is equipped with a filtration membrane for removing foreign matter. The flush water flowing through the flow path 42 is purified by the filtration membrane.

[0035] A pump 41 is connected to the cleaning water tank 40 via a flow path. The pump 41 transfers the cleaning water stored in the cleaning water tank 40 to a cleaning line 61 for the electrode 31.

[0036] In this embodiment, the cleaning water is recycled, which eliminates the need to provide a flow path for cleaning water outside the measurement system 1, allowing the size of the measurement system 1 to be reduced.

[0037] [2] Operation 6 is a flowchart illustrating the operation of the measurement system 1. Total nitrogen measurement and total phosphorus measurement are performed alternately using different electrodes 31 (electrodes 31-1, 31-2). For example, the measurement operations are performed in the order of total nitrogen measurement and total phosphorus measurement.

[0038] The control device 50 uses the pump 10 to transfer the sample S to the pretreatment device 20 (step S100). Subsequently, the control device 50 places the pretreatment electrode 21 in the pretreatment device 20 (step S101).

[0039] Next, the control device 50 electrically oxidizes the sample S in the pretreatment device 20 (step S102). Specifically, the control device 50 applies a voltage to the electrode 21 to oxidize the sample S. The oxidation treatment is performed separately for the total nitrogen measurement and the total phosphorus measurement, and an oxidation treatment appropriate for each measurement is performed.

[0040] The ion reaction formula for inorganic nitrogen and organic nitrogen in total nitrogen measurement is as follows: inorganic nitrogen NH4 + + 2O2 → NO3 - + 2H + + H2O NO2 - + 1 / 2O2 → NO3 - organic nitrogen R-NH3 + + H2O → RH + NH4 + + 1 / 2O2 R: organic side chain The ionic reaction formula for inorganic and organic phosphorus in total phosphorus measurement is as follows: Inorganic phosphorus P2O7 4- + H2O → 2PO4 3- + 2H + P3O 10 5- + 2H2O → 3PO4 3- + 4H + Organic phosphorus R-PO3 2- + H2O → RH + PO4 3- + H + R: organic side chain Next, the control device 50 moves the sample S from the pretreatment device 20 to the measurement device 33 (step S103). Next, the transporter 32 places the electrode 31-1 for measuring total nitrogen in the measurement device 33 (step S104).

[0041] Subsequently, the control device 50 measures the total nitrogen in the sample S in the measurement device 33 (step S105). Specifically, the control device 50 applies a voltage to the electrode 31-1 to measure the total nitrogen in the sample S.

[0042] Subsequently, the control device 50 drains the sample S from the measuring device 33 (step S106). Specifically, the control device 50 uses the valve 36 attached to the lower part of the measuring device 33 to drain the sample.

[0043] Next, the transporter 32 moves the electrode 31-1 from the measuring device 33 to the cleaning device 34 (step S107).

[0044] Next, the control device 50 cleans the electrode 31-1 in the cleaning device 34 (step S108). Specifically, the control device 50 uses the pump 41 to supply cleaning water to the cleaning line 61 attached to the electrode 31-1, thereby cleaning the electrode 31.

[0045] Next, the transporter 32 moves the electrode 31-1 from the cleaning device 34 to the storage device 35 (step S109).

[0046] Next, the control device 50 dries the electrode 31-1 in the storage device 35 (step S110). Specifically, the control device 50 uses the air pump 64 to supply air to the airline 62 attached to the electrode 31-1, thereby drying the electrode 31-1.

[0047] In this way, total nitrogen measurement is performed. Subsequently, the control device 50 performs total phosphorus measurement (step S111). The total phosphorus measurement is performed using the electrode 31-2 for total phosphorus measurement. The process of total phosphorus measurement is the same as steps S100 to S110.

[0048] Thereafter, the above steps are repeated to perform the measurement.

[0049] [3] Effects of the embodiment According to this embodiment, the sample S can be pretreated using an electrochemical reaction. In addition, the total nitrogen and total phosphorus measurements can be performed using an electrochemical reaction. This improves the accuracy of the total nitrogen and total phosphorus measurements.

[0050] The system also includes a measuring device 33 for performing measurements, a cleaning device 34 for cleaning the electrodes 31, and a storage device 35 for drying and storing the electrodes 31. The electrodes 31 for measurement can be moved in this order using a transporter 32 from the measuring device 33 to the cleaning device 34 and then to the storage device 35. This allows repeated measurements to be performed using the same electrodes 31.

[0051] Furthermore, since unused electrodes 31 can be stored in the storage device 35, total nitrogen measurement and total phosphorus measurement can be performed in sequence. This allows total nitrogen and total phosphorus to be measured using the same measurement device. Furthermore, deterioration of the electrodes 31 can be suppressed, allowing the electrodes 31 to be used for a long period of time.

[0052] Furthermore, the measurement electrode 31 can be washed and dried after each measurement, thereby improving the accuracy of the total nitrogen and total phosphorus measurements.

[0053] Furthermore, since the electrode 31 can be washed in a location separate from the measuring device 33, it is possible to prevent the sample from being mixed with the washing water, thereby enabling the electrode 31 to be washed sufficiently.

[0054] Furthermore, cleaning water can be circulated to the cleaning device 34 by using the cleaning water tank 40. This reduces the cost of the measurement.

[0055] In addition, a wave-proof tube 63 is provided around the electrode 31. This reduces the influence of the water flow in the measuring device 33 during measurement, thereby improving the measurement accuracy.

[0056] Furthermore, by measuring total nitrogen and total phosphorus without using chemicals, it is possible to return the wastewater to the sewer.

[0057] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0058] 1...measurement system, 10...pump, 20...pretreatment device, 21...electrode, 22...support member, 23...rotating body, 30...measurement module, 31...electrode, 32...transporter, 33...measuring device, 34...cleaning device, 35...storage device, 36...valve, 40...cleaning water tank, 41...pump, 42...flow path, 50...control device, 61...cleaning line, 62...air line, 63...breakwater pipe, 64...air pump.

Claims

1. a pretreatment device to which a sample is supplied and which performs an electrical oxidation treatment on the sample using a first electrode; a measuring device to which the oxidized sample is supplied and which electrochemically measures total nitrogen or total phosphorus of the sample using a second electrode; a cleaning device to which the second electrode is moved after the measurement and which cleans the second electrode; a storage device to which the second electrode after cleaning is transferred and which stores the second electrode; a transporter that moves the second electrode through the measuring device, the cleaning device, and the storage device in this order; A measurement system comprising:

2. The apparatus further includes a first pump for transferring the sample to the pretreatment device. The measurement system of claim 1 .

3. The second electrode further includes a cleaning line for supplying cleaning water thereto. The measurement system of claim 1 .

4. a cleaning water tank connected to the bottom of the cleaning device and configured to store the cleaning water; a second pump connected to the flushing water tank for transferring the flushing water to the flushing line; Further comprising The measurement system of claim 3 .

5. a flow path connecting the bottom of the cleaning device and the cleaning water tank; The flow path includes a filtration membrane. The measurement system of claim 4 .

6. The storage device includes an airline that delivers air to the second electrode. The measurement system of claim 1 .

7. The pretreatment device includes a rotor that stirs the sample. The measurement system of claim 1 .

8. The second electrode further includes a wave-proof tube configured to surround the side surface of the second electrode. The measurement system of claim 1 .

9. and a valve connected to the bottom of the measuring device for draining the sample. The measurement system of claim 1 .

10. The measuring device repeatedly measures total nitrogen and total phosphorus. The measurement system of claim 1 .

11. a sample is supplied to a pretreatment device, and the sample is electrically oxidized using a first electrode; the oxidized sample is supplied to a measurement device, and total nitrogen or total phosphorus is measured electrochemically on the sample using a second electrode; In a cleaning device, the second electrode after the measurement is moved and the second electrode is cleaned; the second electrode after cleaning is moved to a storage device, and the second electrode is stored; a transporter for transporting the second electrode to the measuring device, the cleaning device, and the storage device in this order; Measurement method.

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