CN115340173B - Operation index calculation method and device, and drainage treatment method and device - Google Patents
Operation index calculation method and device, and drainage treatment method and device Download PDFInfo
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- 238000004364 calculation method Methods 0.000 title claims description 17
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- 239000007789 gas Substances 0.000 claims abstract description 165
- 239000002351 wastewater Substances 0.000 claims abstract description 68
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 44
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- 230000033116 oxidation-reduction process Effects 0.000 claims abstract description 12
- 230000020477 pH reduction Effects 0.000 claims abstract 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 410
- 239000001569 carbon dioxide Substances 0.000 claims description 203
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 203
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- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- IOVCWXUNBOPUCH-UHFFFAOYSA-N Nitrous acid Chemical compound ON=O IOVCWXUNBOPUCH-UHFFFAOYSA-N 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 1
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- 238000009825 accumulation Methods 0.000 description 1
- 238000005273 aeration Methods 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 150000003863 ammonium salts Chemical class 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
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- 229910052748 manganese Inorganic materials 0.000 description 1
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- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 235000018343 nutrient deficiency Nutrition 0.000 description 1
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- 239000002245 particle Substances 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F3/00—Biological treatment of water, waste water, or sewage
- C02F3/006—Regulation methods for biological treatment
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2209/00—Controlling or monitoring parameters in water treatment
- C02F2209/08—Chemical Oxygen Demand [COD]; Biological Oxygen Demand [BOD]
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2209/00—Controlling or monitoring parameters in water treatment
- C02F2209/24—CO2
- C02F2209/245—CO2 in the gas phase
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2209/00—Controlling or monitoring parameters in water treatment
- C02F2209/38—Gas flow rate
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2305/00—Use of specific compounds during water treatment
- C02F2305/06—Nutrients for stimulating the growth of microorganisms
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W10/00—Technologies for wastewater treatment
- Y02W10/10—Biological treatment of water, waste water, or sewage
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Molecular Biology (AREA)
- Biodiversity & Conservation Biology (AREA)
- Microbiology (AREA)
- Hydrology & Water Resources (AREA)
- Health & Medical Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Activated Sludge Processes (AREA)
- Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)
Abstract
When the organic wastewater is biologically treated by the biological treatment tank (10), an operation index is calculated based on a relationship (model or relationship) previously obtained for the treatment amount (for example, concentration) of the gas discharged from the water in the biological treatment tank (10), the water quality of the water in the biological treatment tank (10), and the water quality of the water to be treated flowing into the biological treatment tank (10), based on the treatment amount of the gas measured by the gas measuring unit (31) and the water quality measured by the water quality measuring unit (32). The water quality measured for the water within the biological treatment tank (10) includes at least one of water temperature, pH, and oxidation-reduction potential (ORP). The operation index is at least one of the concentration of organic matters, the concentration of nitrogen, the concentration of phosphorus, the concentration of dissolved oxygen and the ORP in the water to be treated.
Description
Technical Field
The present invention relates to treatment of organic wastewater by biological treatment, and more particularly to a method and a device for calculating an operation index for biological treatment, a method for treating wastewater, and a device for treating wastewater.
Background
As a wastewater treatment performed before organic wastewater, which is wastewater containing organic matters, is discharged to the environment, biological treatment using microorganisms is widely used. In biological treatment, organic wastewater is introduced into a biological treatment tank as a treatment target water. In biological treatment, in order to maintain high decomposition activity of organic substances by microorganisms, it is necessary to optimize environmental conditions such as water temperature and pH and to add nutrients such as nitrogen, phosphorus and trace metals to a biological treatment tank. In the drain from the factory, the nutrients are liable to be insufficient as compared with the drain in the public sewer where the domestic drain flows in. In particular, in the drainage from chemical plants and semiconductor manufacturing plants, the shortage of nutrients required for biological treatment is significant. The wastewater treatment method and the wastewater treatment apparatus based on biological treatment are also called a biological treatment method and a biological treatment apparatus, respectively.
The amount of the nutrient added to the water to be treated as the organic wastewater is recommended to be proportional to the concentration of the organic matter in the water to be treated. The organic matter concentration in the water to be treated is expressed as Biochemical Oxygen Demand (BOD), and the preferable addition amounts of nitrogen (N) and phosphorus (P) in the wastewater treatment by the aerobic microorganisms, that is, in the aerobic treatment, are, for example, BOD on a mass basis: n: p=100: 5:1. in order to determine the amount of nutrient added, it is necessary to obtain the BOD value of the water to be treated flowing into the biological treatment tank. Although it is difficult to perform BOD measurements on-line or in a short time, measurement of Total Organic Carbon (TOC) concentration in water can be performed on-line. As an example, patent document 1 discloses that correlation between TOC concentration and BOD in water to be treated is obtained in advance, and the TOC concentration of the water to be treated is monitored by an online TOC concentration meter, and then converted into a BOD value, and the addition amount of nitrogen and phosphorus is controlled based on the obtained BOD value. Here, when biological treatment is performed in a biological treatment tank, the BOD value is used as an operation index for determining an operation condition such as an amount of nutrient added.
When the amount of nutrient added is controlled based on the online TOC concentration, clogging may occur in the piping of the online TOC concentration meter due to Suspended Substances (SS), accumulation of oil, formation of biofilm, and the like, and the measured value becomes unstable. As a method of estimating a BOD value without using a TOC concentration meter, patent document 2 discloses that, when organic wastewater is biologically treated to obtain wastewater, the concentration of carbon dioxide generated by the biological treatment is measured, and the BOD value in the wastewater is estimated based on the carbon dioxide concentration. Patent document 2 also discloses control of biological treatment by using an estimated BOD value as an operation index, for example, by increasing the amount of returned sludge.
The method disclosed in patent document 2 is a method of estimating a BOD value based on a rate of production of inorganic carbonic acid by biological treatment in proportion to a concentration of organic substances in discharged water, and adjusting treatment using the estimated BOD value as an operation index. However, the inorganic carbonic acid in water is dependent on the pH of the water, carbon dioxide (CO 2 ) Bicarbonate ion (HCO) 3 - ) Carbonate ion (CO) 3 2- ) And its form changes, bicarbonate ions and carbonate ions remain in water, so measuring only the carbon dioxide concentration is insufficient to infer the amount of carbon dioxide produced in biological treatment. Further, in general, the solubility of a dissolved gas depends on the temperature, and there is an inorganic carbonic acid component remaining in water in the form of carbon dioxide, and the amount thereof depends on the temperature, so it is difficult to accurately estimate the carbon dioxide generation rate generated in biological treatment by measuring only the carbon dioxide concentration in the gas phase. As a result, it is difficult to obtain an accurate BOD value by the method described in patent document 2, and the calculation method as an operation index is not suitable.
In the method described in patent document 2, the treatment by the activated sludge process is adjusted based on the BOD value of the discharged water, for example, by increasing the amount of returned sludge. However, this method does not estimate the BOD value of the influent water to be treated, but estimates the BOD value of the discharged water, and thus causes a time delay when the treatment by the activated sludge process is adjusted. As a result, the BOD value calculated by the method described in patent document 2 is not suitable as an operation index. Further, in the method described in patent document 2, the ventilation amount is adjusted based on the BOD value of the discharged water, for example. When the ventilation amount is adjusted to increase, the carbon dioxide generated in the biological treatment is diluted, and it is difficult to accurately estimate the increase or decrease in the carbon dioxide generated in the biological treatment. In this regard, it is also difficult to obtain an accurate BOD value by the method described in patent document 2, and a calculation method as an operation index is not suitable.
[ Prior Art literature ]
[ patent literature ]
Patent document 1: japanese patent laid-open No. 2001-334285
Patent document 2: japanese patent laid-open No. 54-60765
Disclosure of Invention
Problems to be solved by the invention
As described above, in the method of controlling the amount of nutrient addition by measuring the TOC concentration on line during the biological treatment, the measured value of the TOC concentration may become unstable, and as a result, the amount of nutrient addition cannot be optimized. Further, as described in patent document 2, in the case of estimating the BOD value from the concentration of carbon dioxide generated by biological treatment, it is difficult to accurately estimate the BOD value, and the amount of nutrient added cannot be optimized.
The present invention aims to provide a drainage treatment method and a drainage treatment device, which can optimize the addition amount of nutrient substances to organic drainage when the organic drainage is treated by biological treatment.
Another object of the present invention is to provide a calculation method and a calculation device capable of rapidly estimating an accurate operation index for controlling biological treatment when performing organic wastewater treatment by biological treatment, and a wastewater treatment method and a wastewater treatment device for performing controlled biological treatment based on the calculated operation index.
Means for solving the problems
In the method for calculating an operation index used when biological treatment of organic wastewater is performed by a biological treatment tank, the operation index is calculated based on a relationship obtained in advance for a treatment amount of gas discharged from water in the biological treatment tank, a water quality of water in the biological treatment tank, and a water quality of water to be treated flowing into the biological treatment tank, the treatment amount of gas is at least one of a concentration of gas, a flow rate, a volume, a pressure, and a substance amount, the water quality of water in the biological treatment tank includes at least one of a water temperature, a pH, and an oxidation-reduction potential, and the operation index is at least one of a concentration of organic substance in the water to be treated, a nitrogen concentration, a phosphorus concentration, a dissolved oxygen concentration, and an oxidation-reduction potential.
The drainage treatment method according to the present invention is a method for biologically treating organic drainage, in which an operation index is calculated by the calculation method according to the present invention, and control is performed in accordance with the calculated operation index, and biological treatment of water to be treated is performed in a biological treatment tank.
Another wastewater treatment method according to the present invention is a method for biologically treating organic wastewater in a biological treatment tank, comprising: a first measurement step of measuring a carbon dioxide concentration in a gas discharged from water in the biological treatment tank; a second measurement step of acquiring 1 or more measurement values related to the water quality of the water in the biological treatment tank; and a control step of controlling the amount of nutrient added to the organic wastewater based on the measured value of the carbon dioxide concentration obtained in the first measurement step and the measured value of 1 or more obtained in the second measurement step.
Still another wastewater treatment method according to the present invention is a method for biologically treating organic wastewater in a biological treatment tank, comprising: a first measurement step of measuring a concentration of a specific gas in a gas discharged from water in the biological treatment tank; a second measurement step of measuring a flow rate of the gas supplied to the biological treatment tank or a flow rate of the gas discharged from the biological treatment tank; and a control step of controlling the amount of nutrient added to the organic wastewater based on the measured value of the concentration obtained in the first measurement step and the measured value of the flow rate obtained in the second measurement step.
The calculation device according to the present invention is a calculation device for calculating an operation index used when biological treatment is performed on organic wastewater in a biological treatment tank, and includes: a gas measurement unit that measures a treatment amount of gas discharged from water in the biological treatment tank; a water quality measuring unit for measuring the water quality of the water in the biological treatment tank; an operation unit that calculates an operation index from a measured value in the gas measurement unit and a measured value in the water quality measurement unit based on a relationship obtained in advance for a treatment amount of gas discharged from water in the biological treatment tank, a water quality of water in the biological treatment tank, and a water quality of water to be treated flowing into the biological treatment tank, the treatment amount of gas being at least one of a concentration, a flow rate, a volume, a pressure, and an amount of a substance of the gas, the water quality of water in the biological treatment tank including at least one of a water temperature, a pH, and an oxidation-reduction potential, and the operation index being at least one of an organic substance concentration, a nitrogen concentration, a phosphorus concentration, a dissolved oxygen concentration, and an oxidation-reduction potential in the water to be treated.
The drainage treatment device according to the present invention is a device for biological treatment of organic drainage, comprising: a computing device according to the invention; and an adding unit that adds a nutrient to the water to be treated and/or a gas dispersing unit that disperses gas into the biological treatment water tank, at least one of the adding unit and the gas dispersing unit being controlled in accordance with the calculated operation index.
Another drainage treatment device according to the present invention includes: a biological treatment tank for biologically treating organic wastewater; an adding unit that adds a nutrient to the organic wastewater; a first measurement unit having a first sensor that measures a carbon dioxide concentration in a gas discharged from water in the biological treatment tank; a second measurement unit that acquires 1 or more measurement values related to the water quality of the water in the biological treatment tank; and a control unit that controls the addition amount of the nutrient added by the addition unit based on the carbon dioxide concentration value obtained by the first measurement unit and 1 or more measurement values obtained by the second measurement unit.
A further drainage treatment device according to the present invention includes: a biological treatment tank for biologically treating organic wastewater; an adding unit that adds a nutrient to the organic wastewater; a first measurement unit that measures a concentration of a specific gas among gases discharged from water in the biological treatment tank; a second measurement unit that measures a flow rate of the gas supplied to the biological treatment tank or a flow rate of the gas discharged from the biological treatment tank; and a control unit that controls the addition amount of the nutrient added by the addition unit based on the measured value of the concentration obtained by the first measurement unit and the measured value of the flow rate obtained by the second measurement unit.
Drawings
Fig. 1 is a view showing a drainage treatment device according to a first embodiment of the present invention.
Fig. 2 is a view showing another example of the drainage treatment device according to the first embodiment.
Fig. 3 is a view showing still another example of the drainage treatment device according to the first embodiment.
Fig. 4 is a view showing a drainage treatment device according to a second embodiment.
Fig. 5 is a view showing another example of the drainage treatment device according to the second embodiment.
Fig. 6 is a view showing still another example of the drainage treatment device according to the second embodiment.
Fig. 7 is a diagram showing a drainage treatment device according to a third embodiment provided with a computing device according to the present invention.
Fig. 8 is a flowchart showing a calculation process of the operation index.
Fig. 9 is a diagram showing an example of the structure of a database.
Fig. 10 is a view showing another example of the drainage treatment device according to the third embodiment.
Fig. 11 is a view showing still another example of the drainage treatment device according to the third embodiment.
Detailed Description
Next, embodiments of the present invention will be described with reference to the drawings.
The present invention relates to a technology for decomposing and removing organic substances in water to be treated, which is organic wastewater, by biological treatment using microorganisms. The organic drainage to be used in the present invention is not particularly limited as long as it can be biologically treated, and includes, for example, drainage from public sewage, food factories, chemical factories, semiconductor manufacturing factories, liquid crystal manufacturing factories, pulp factories, and drainage from business places in other fields than those. In the wastewater from a civil factory, a nutrient necessary for maintaining the decomposition activity of microorganisms used in biological treatment is liable to be insufficient, as compared with the wastewater from a public sewer, and in particular, in the wastewater from a chemical factory, a semiconductor manufacturing factory, or a liquid crystal manufacturing factory, the nutrient deficiency is remarkable. The organic wastewater to which an external organic source such as methanol is added when denitrification is performed by adding the external organic source to inorganic nitric acid wastewater (or inorganic nitrous acid wastewater) containing no organic matter is also the organic wastewater to which the present invention is directed. The biological treatment in the present invention includes aerobic treatment, anaerobic treatment, denitrification treatment, etc., which are performed by an activated sludge process, a membrane separation activated sludge process (MBR), a fluidized bed or fixed bed biofilm process, a particle process, etc.
First embodiment
Fig. 1 shows a drainage treatment device according to a first embodiment of the present invention. The wastewater treatment apparatus shown in fig. 1 includes a fluidized-bed type biological treatment tank 10 for storing water to be treated as organic wastewater and performing biological treatment of the organic wastewater under aerobic conditions. The treated water from which the organic matter is decomposed and removed by the biological treatment is discharged from the biological treatment tank 10. The biological treatment tank 10 is filled with a carrier 11, and a gas diffusing device 12 for blowing air into the biological treatment tank 10 for supplying oxygen, that is, for ventilation is provided at the bottom of the biological treatment tank 10. An inlet pipe 13 for supplying water to be treated to the biological treatment tank 10 is connected to the biological treatment tank 10. A gas pipe 14 for supplying air to the air diffusing device 12 is connected to the air diffusing device 12, and a blower 15 for supplying air is provided in the gas pipe 14. Examples of the carrier 11 that can be used here include plastic carriers, sponge carriers, gel carriers, and the like, and among them, sponge carriers are preferably used from the viewpoints of cost and durability. The biological treatment tank 10 may be provided with a stirring device for stirring the carrier 11.
In biological treatment, in order to maintain the decomposition activity of microorganisms high and to reproduce them, a nutrient is required, and when the nutrient in the water to be treated is insufficient, it is necessary to add a nutrient to the water to be treated in the biological treatment tank 10 or at a stage preceding the biological treatment tank 10. In the drainage treatment device according to the first embodiment, a nutrient tank 21 for storing a nutrient solution (i.e., nutrient solution) is provided, and the nutrient tank 21 and the inlet pipe 13 are connected via a nutrient solution pipe 22. The pump 23 for supplying the nutrient solution is provided in the nutrient solution piping 22. Therefore, in this drain treatment apparatus, a nutrient can be added to the organic drain flowing through the inlet pipe 13 and supplied to the biological treatment tank 10, and the amount of the nutrient added to the organic drain can be controlled by controlling the pump 23. Nutrient substances are roughly classified into nutrient salts containing nitrogen and phosphorus and trace elements which are required in a smaller amount than nitrogen and phosphorus. The microelements comprise alkali metals such as sodium, potassium, calcium and magnesium, metals such as ferrum, manganese and zinc, etc. As the nitrogen source, urea and ammonium salts can be used. As the phosphorus source, phosphoric acid and phosphate can be used.
In the wastewater treatment apparatus according to the first embodiment, the amount of nutrient added is controlled based on the carbon dioxide concentration in the gas discharged from the water in the biological treatment tank 10 by the biological treatment and the BOD concentration of the water to be treated calculated from 1 or more measurement values related to the water quality of the water in the biological treatment tank 10. Therefore, the biological treatment tank 10 is provided with: a carbon dioxide concentration sensor 31 that measures the concentration of carbon dioxide in the gas discharged from the water in the biological treatment tank 10; and a water quality measuring unit 33 that measures water quality for 1 or more items. The biological treatment tank 10 is covered with a cover 16, and the carbon dioxide concentration sensor 31 is provided in a gas phase portion in the biological treatment tank 10, a pipe connected to the gas phase portion, and the like. Since dew condensation of the carbon dioxide concentration sensor 31 needs to be avoided, when the moisture separator is provided in the pipe, heat preservation of the pipe and the like can be achieved, and the moisture separator can be provided at a position immediately in front of the carbon dioxide concentration sensor 31. In addition, a desulfurization device or the like for removing corrosive gas may be provided. In the case where the biological treatment tank 10 is an open system, in order to reduce the influence of the outside air in the measurement result, a cylindrical pipe or the like can be inserted under the water surface in order to minimize the open portion in the upper portion of the biological treatment tank 10, and the carbon dioxide concentration sensor 31 can be disposed at a position on the water surface in the pipe. As the carbon dioxide concentration sensor 31, for example, an electrochemical sensor or a semiconductor sensor can be used, and a sensor by a non-dispersive infrared absorption method (NDIR) is particularly preferably used. The measurement of the carbon dioxide concentration may be performed manually (manual) or on-line.
Examples of the water quality of the water in the biological treatment tank 10 include pH (hydrogen ion concentration index), water temperature, dissolved oxygen concentration (DO), oxidation-reduction potential (ORP), conductivity, turbidity, and the like, as items measured by the water quality measuring unit 33. The water quality measuring unit 33 is configured to be able to measure 1 or more items. It is well known that the form of inorganic carbonic acid in water changes to CO according to pH 2 ，HCO 3 - ，CO 3 2- It is therefore considered that the relationship between pH and the carbon dioxide concentration in the gas discharged from the water in the biological treatment tank 10 by the biological treatment is particularly large. Further, since the solubility water temperature of carbon dioxide varies depending on the water temperature, the water temperature is also greatly related to the carbon dioxide concentration in the gas discharged from the water in the biological treatment tank 10. In the first embodiment, the measured value including the concentration of carbon dioxide discharged by the biological treatment is used instead of actually measuring the BOD of the water to be treated, and therefore, the items measured by the water quality measuring unit 33 preferably include pH and water temperature. The measurement in the water quality measuring section 33 may be performed manually or on-line.
Although there is also an online TOC concentration meter that measures the Total Organic Carbon (TOC) concentration in water online, the online TOC concentration meter is provided with a thin piping for introducing a small amount of sample water into the measuring device, and is prone to clogging and unstable in measurement value. On the other hand, since the carbon dioxide concentration sensor 31 performs measurement without being in contact with water, the stability of the measured value is very high. The water quality measuring unit 33 for measuring pH, water temperature, and the like is also a sensor immersed in the biological treatment tank 10, and thus the stability of the measured value is high.
Next, control of the amount of nutrient added to the drainage treatment device shown in fig. 1 will be described. It is recommended that the amount of nutrient (nutrient salt and trace metal) added to the water to be treated be proportional to the concentration of organic matter in the water to be treated, preferably to BOD. For example, it is recommended that the addition amounts of nitrogen (N) and phosphorus (P) in the aerobic treatment be defined as BOD on a mass basis: n: p=100: 5:1. in the first embodiment, the BOD of the water to be treated is not measured by an online TOC concentration meter or the like, but instead, the carbon dioxide concentration in the gas discharged from the water in the biological treatment tank 10 by the biological treatment and the water quality of the water in the biological treatment tank 10 are measured. Further, a BOD value of the water to be treated is calculated from the measured value of the carbon dioxide concentration and 1 or more measured values related to the water quality, and the addition amount of the nutrient is determined based on the calculated BOD value. For this purpose, in the first embodiment, a combination of the carbon dioxide concentration measured by the carbon dioxide concentration sensor 31 and the measured value obtained by the water quality measuring unit 33 is first used as an input value (Xn), the BOD concentration of the water to be treated corresponding to the input value (Xn) is used as an output value (Yn), and a model (or relational expression) is created by acquiring a combination of a predetermined number (for example, several tens to several hundreds) of input values and output values in advance. Once the model is created, a combination of the measured value of the carbon dioxide concentration measured by the carbon dioxide concentration sensor 31 and the measured value obtained by the water quality measuring unit 33 is input to the model, and as a result, the pump 23 is driven based on the BOD concentration value output from the model to control the addition or non-addition of the nutrient to the water to be treated. In order to perform such control, the drain treatment apparatus includes a control device 40, and the control device 40 holds the created model, applies the carbon dioxide concentration value obtained by the carbon dioxide concentration sensor 31 and the measured value obtained by the water quality measuring unit 33 to the model to calculate the BOD concentration value of the water to be treated, and controls the start/stop and flow rate of the pump 23 based on the BOD concentration value.
Next, creation of a model in the first embodiment will be described. When the input value is input, a model for outputting the BOD concentration of the water to be treated corresponding to the input value as an output value can be created using, for example, various regression analyses. In particular, if a model is created by supervised learning using a neural network technique, the accuracy of control of the addition amount of nutrients improves. The carbon dioxide concentration obtained by the carbon dioxide concentration sensor 31 may vary depending on the structure and size of the biological treatment tank 10, the size of the gas phase portion in the biological treatment tank 10, the type of biological treatment, and the like, and thus the model may be set for each biological treatment tank 10. Further, since the relationship between the BOD of the water to be treated and the measured carbon dioxide concentration and pH may vary depending on the type or source of the water to be treated as the organic wastewater, a model for controlling the amount of the nutrient to be added may be prepared for each type or source of the water to be treated, and a model for controlling the amount of the nutrient to be added may be selected from the models thus prepared depending on the type or source of the water to be treated.
In the drainage treatment apparatus shown in fig. 1, air is blown into the biological treatment tank 10, but the atmosphere generally contains about 400ppm of carbon dioxide. When measuring the carbon dioxide concentration to estimate the amount of carbon dioxide produced by biological treatment, it is necessary to consider the amount of carbon dioxide originally contained in the blown air. In the case where the variation in the amount of carbon dioxide in the blown air is small, since the contribution of carbon dioxide contained in the blown air is already contained in the model created as described above, the model can be used to determine the addition amount of the nutrient without measuring the carbon dioxide concentration in the blown air. However, when the carbon dioxide concentration in the blown air fluctuates, for example, in the case where air mixed with the exhaust gas of the boiler in the factory is blown, it is necessary to determine the amount of the nutrient to be added by modifying the carbon dioxide concentration in the gas blown into the biological treatment tank 10. Fig. 2 shows a drain treatment apparatus modified in accordance with the concentration of carbon dioxide blown into the biological treatment tank 10.
The drainage treatment device shown in fig. 2 is similar to the drainage treatment device shown in fig. 1, but is different from that shown in fig. 1 in that a carbon dioxide concentration sensor 35 is provided in the gas pipe 14 at a position on the outlet side of the blower 15 in order to measure the carbon dioxide concentration in the blown-in air. The measured value of the carbon dioxide concentration sensor 35 provided in the gas pipe 14 is also sent to the control device 40. The control device 40 calculates a difference between the measured value of the carbon dioxide concentration sensor 31 and the measured value of the carbon dioxide concentration sensor 35, applies the difference and the measured value obtained by the water quality measuring unit 33 to a model, calculates a BOD concentration value of the water to be treated, and controls the pump 23 based on the BOD concentration value.
In the drainage treatment, a plurality of biological treatment tanks for biological treatment are connected in series, and the treatment water discharged from the preceding biological treatment tank is introduced into the subsequent biological treatment tank, and biological treatment is performed in each biological treatment tank to obtain treatment water from which organic substances are highly removed. Fig. 3 shows a drainage treatment device in which a plurality of biological treatment tanks 10 for performing biological treatment are provided in series, i.e., in multiple stages. Preferably, when the biological treatment tank 10 is provided in a plurality of stages of 2 or more stages, the concentration of carbon dioxide in the gas discharged from the biological treatment tank is measured in the biological treatment tank 10 at the foremost stage, 1 or more measured values related to the quality of water in the biological treatment tank 10 are obtained, the BOD concentration value of the water to be treated is calculated, and the amount of nutrient added to the water to be treated supplied to the biological treatment tank 10 at the foremost stage is controlled based on the BOD concentration value. Therefore, in the drainage treatment device shown in fig. 3, the carbon dioxide concentration sensor 31 and the water quality measuring unit 33 are provided in the biological treatment water tank 10 at the forefront stage, and the nutrient solution from the nutrient tank 21 is added to the water to be treated in the inlet pipe 13 connected to the biological treatment water tank 10 at the forefront stage. The control device 40 calculates the BOD concentration value of the water to be treated from the measured values of the carbon dioxide concentration sensor 31 and the water quality measuring unit 33, and controls the pump 23 for supplying the nutrient solution based on the BOD concentration value.
When the biological treatment tanks 10 are arranged in series at 2 or more stages, most of the organic matters are decomposed and removed in the biological treatment tank 10 at the foremost stage, and therefore, the organic matters to be removed in the biological treatment tanks 10 at the 2 nd and subsequent stages are reduced. Moreover, the microorganisms propagated in the foremost biological treatment tank 10 die and disintegrate, whereby nutrients are dissolved again. For these reasons, even if nutrients are not newly added to the water supplied to the biological treatment tank 10 of the 2 nd and subsequent stages, biological treatment can be advanced in the biological treatment tank 10 of the 2 nd and subsequent stages, and the overall treatment performance of the drainage treatment apparatus can be maintained.
Second embodiment
Next, a second embodiment of the present invention will be described. In the second embodiment, the organic wastewater is supplied to the biological treatment tank as treated water, and the concentration of a specific gas in the gas discharged from the water in the biological treatment tank and the flow rate of the gas supplied to the biological treatment tank or the gas discharged from the biological treatment tank are measured instead of directly measuring the BOD or TOC concentration of the treated water in order to optimize the amount of the nutrient added to the treated water. The amount of nutrient added to the water to be treated is controlled based on the measured value of the concentration of the specific gas and the measured value of the flow rate of the gas. In this case, the organic matter concentration of the water to be treated may be calculated from the measured concentration value and the measured flow rate value, and the amount of nutrient added to the water to be treated may be controlled based on the calculated organic matter concentration, or the amount of nutrient added to the water to be treated may be controlled based on a value obtained by multiplying the measured concentration value and the measured flow rate value. Further, the water quality (e.g., pH) of the water in the biological treatment tank may be measured, and the amount of nutrient added to the water to be treated may be controlled based on the measured value of the concentration of the specific gas, the measured value of the flow rate, and the measured value of the water quality.
If the biological treatment is an aerobic treatment, the concentration of the specific gas is measured, for example, as the concentration of carbon dioxide generated from water in the biological treatment tank. In the aerobic treatment, since the air is blown into the biological treatment tank by providing a blower for blowing air or the like, and the air is dispersed or ventilated into the biological treatment tank, the flow rate of the air supplied from the blower for blowing air to the biological treatment tank or the flow rate of the entire gas discharged from the biological treatment tank may be measured as the flow rate of the gas. In the case of performing the aerobic treatment using the fluidized bed, a screen is placed in the biological treatment tank to separate the carrier, and air is blown in during cleaning of the screen, but in this case, a value obtained by adding the air volume of the blower for diffusing air and the air volume of the air for cleaning the screen may be used as the flow rate of the gas. If the biological treatment is anaerobic treatment, for example, the concentration of methane generated from water in the biological treatment tank is measured as the concentration of a specific gas, and since the gas is not dispersed in the anaerobic treatment, the flow rate of the whole gas discharged from the biological treatment tank may be measured as the flow rate of the gas.
Fig. 4 shows a drainage treatment device according to a second embodiment. The drainage treatment device shown in fig. 4 includes a fluidized bed type biological treatment tank 10 for storing water to be treated as organic drainage and performing biological treatment of the water to be treated under aerobic conditions. The treated water from which the organic matter is decomposed and removed by the biological treatment is discharged from the biological treatment tank 10. The biological treatment tank 10 shown in fig. 4 is filled with a carrier 11, and is provided with a gas dispersing device 12, and an inlet pipe 13 is connected thereto, similarly to the biological treatment tank 10 of the first embodiment shown in fig. 1. The gas pipe 14 is connected to the gas diffusing device 12, and a blower 15 for supplying air is provided in the gas pipe 14. As the carrier 11, the same carrier as that described in the first embodiment is used. The biological treatment tank 10 may be provided with a stirring device for stirring the carrier 11. In the same manner as in the drainage treatment device shown in fig. 1, a nutrient tank 21 may be provided in the drainage treatment device shown in fig. 4, and the nutrient tank 21 and the inlet pipe 13 may be connected via a nutrient solution pipe 22. The pump 23 for supplying the nutrient solution is provided in the nutrient solution piping 22. As the nutrient substance, the same substances as those described in the first embodiment can be used.
In the drainage treatment device according to the second embodiment, the amount of nutrient added is controlled based on the carbon dioxide concentration in the gas discharged from the water in the biological treatment tank 10 by the biological treatment and the flow rate of the air supplied to the biological treatment tank 10 for the purpose of aeration. Accordingly, the biological treatment tank 10 is provided with a carbon dioxide concentration sensor 31 for measuring the concentration of carbon dioxide in the gas discharged from the water in the biological treatment tank 10, and a gas meter 32 for measuring the flow rate of the air flowing therein is provided in the gas pipe 14 at a position between the blower 15 and the gas dispersing device 12. The kind of the carbon dioxide concentration sensor 31 and the arrangement form thereof are the same as those of the first embodiment. Therefore, a moisture separator and a desulfurization device may be provided to the carbon dioxide concentration sensor 31.
Next, control of the amount of nutrient added to the drainage treatment device shown in fig. 4 will be described. As described above, it is recommended that the amount of nutrient (nutrient salt and trace metal) added to the water to be treated be proportional to the concentration of organic matter in the water to be treated, preferably to BOD. For example, it is recommended that the addition amounts of nitrogen (N) and phosphorus (P) in the aerobic treatment be defined as BOD on a mass basis: n: p=100: 5:1. in the second embodiment, instead of measuring the BOD of the water to be treated by an online TOC concentration meter or the like, the carbon dioxide concentration in the gas discharged from the water in the biological treatment tank 10 by the biological treatment and the flow rate (i.e., the air volume) of the air supplied to the biological treatment tank 10 for the purpose of air dispersion are measured. Further, a BOD value of the water to be treated is calculated from the measured value of the carbon dioxide concentration and the measured value of the flow rate of the air, and the addition amount of the nutrient is determined based on the calculated BOD value. For this purpose, in the second embodiment, first, a combination of the carbon dioxide concentration measured by the carbon dioxide concentration sensor 31 and the measured value of the air volume obtained by the air volume meter 32 is used as an input value (Xn), the BOD concentration of the water to be treated corresponding to the input value (Xn) is used as an output value (Yn), and a model (or relational expression) is created by acquiring a combination of a predetermined number (for example, several tens to several hundreds) of input values and output values in advance. In this case, instead of using a combination of the measured value of the carbon dioxide concentration and the measured value of the air volume as the input value (Xn), a value obtained by multiplying the measured value of the carbon dioxide concentration by the measured value of the air volume (i.e., a product) may be used as the input value (Xn).
Once the model is created, a combination of the measured value of the carbon dioxide concentration measured by the carbon dioxide concentration sensor 31 and the measured value of the air volume obtained by the air volume meter 32 is input to the model, and as a result, the pump 23 is driven based on the BOD concentration value output from the model, and the addition or non-addition of the nutrient to the water to be treated is controlled. In order to perform such control, the drain treatment apparatus includes a control device 40, and the control device 40 holds the created model, applies the carbon dioxide concentration value obtained by the carbon dioxide concentration sensor 31 and the measured value obtained by the air gauge 32 to the model to calculate the BOD concentration value of the water to be treated, and controls the start/stop and flow rate of the pump 23 based on the BOD concentration value. In addition, although the BOD concentration is used for creating the model, the created model itself can be considered to be a model in which the measured value of the carbon dioxide concentration and the measured value of the air volume are taken as inputs and the addition amount of the nutrient is directly outputted, and therefore, once the model is created, it is not necessary to explicitly calculate the BOD concentration value from the measured value of the carbon dioxide concentration and the measured value of the air volume, and the optimal addition amount of the nutrient can be determined.
Next, creation of a model will be described. When the input value is input, a model for outputting the BOD concentration of the water to be treated corresponding to the input value as an output value can be created using, for example, various regression analyses. In particular, if a model is created by supervised learning using a neural network technique, the accuracy of control of the addition amount of nutrients improves. The carbon dioxide concentration obtained by the carbon dioxide concentration sensor 31 may vary depending on the structure and size of the biological treatment tank 10, the size of the gas phase portion in the biological treatment tank 10, the type of biological treatment, etc., and the air volume of the air supplied to the biological treatment tank 10 for air dispersion may vary depending on the structure, size, etc. of the biological treatment tank 10, so that the model may be set for each biological treatment tank 10. Further, since the relationship between the BOD of the water to be treated and the measured carbon dioxide concentration and air volume may vary depending on the type and origin of the water to be treated, a model for controlling the amount of nutrient added can be prepared for each type and origin of the water to be treated, and a model for controlling the amount of nutrient added can be selected from among the models prepared in this way depending on the type and origin of the water to be treated.
In the drainage treatment device shown in fig. 4, the air meter 32 is provided in the gas pipe 14 to measure the flow rate of the air supplied to the biological treatment tank 10 via the gas pipe 14, but may be provided to measure the flow rate of the air discharged from the biological treatment tank 10 instead of the flow rate of the air supplied to the biological treatment tank 10. In the case of measuring the flow rate of the gas discharged from the biological treatment tank 10, when the biological treatment tank 10 is completely covered with the cover 16, the air gauge 32 may be provided in a pipe communicating with the inside of the biological treatment tank 10 for discharging the gas to the outside. In the case where the biological treatment tank 10 is an open system, in order to reduce the influence of the outside air in the measurement result, a tubular pipe or the like can be inserted under the water surface in order to minimize the open portion in the upper portion of the biological treatment tank 10, and the air gauge 32 can be provided in the pipe.
In order to control the amount of nutrient added to the water to be treated, it is also considered to measure the concentration of organic substances in the water to be treated on line using an on-line TOC concentration meter, but the on-line TOC concentration meter is provided with a thin pipe for introducing a small amount of sample water into the measuring device, and clogging is likely to occur, and the measured value is unstable. In contrast, the carbon dioxide concentration sensor 31 measures without being in contact with water, and thus the stability of the measured value is very high. In addition, the gas flow rate can be measured stably. Therefore, in the drainage treatment device according to the second embodiment, the optimum value of the amount of the nutrient to be added to the water to be treated can be obtained stably without directly measuring the concentration of the organic substance in the water to be treated.
Fig. 5 shows another example of the drainage treatment device of the second embodiment. The drain treatment apparatus shown in fig. 5 is a drain treatment apparatus shown in fig. 4, in which a water quality measuring unit 33 for measuring the water quality of water in the biological treatment tank 10 is provided, and the measurement result in the water quality measuring unit 33 is also sent to the control device 40. The water quality items measured by the water quality measuring unit 33 include at least pH, and water temperature and the like may be measured in addition to pH. In this case, the model used in the drainage treatment device is a model created in the same manner as the model described above, in which a combination of the carbon dioxide concentration measured by the carbon dioxide concentration sensor 31, the measured value of the air volume obtained by the air volume meter 32, and the measured value of the water quality (in particular, pH) measured by the water quality measuring unit 33 is used as the input value (Xn), and the BOD concentration of the water to be treated corresponding to the input value (Xn) is used as the output value (Yn). The control device 40 applies the measured value of the carbon dioxide concentration measured by the carbon dioxide concentration sensor 31, the measured value of the air volume obtained by the air volume meter 32, and the measured value of the water quality (in particular, pH) measured by the water quality measuring unit 33 to a model, calculates the BOD concentration value of the water to be treated, and controls the pump 23 based on the BOD concentration value.
As described above, even if the concentration of the organic matter in the water to be treated is the same, the concentration of carbon dioxide in the gas discharged from the water in the biological treatment tank 10 may vary depending on the pH. In the drainage treatment device shown in fig. 5, the amount of nutrient added is controlled in consideration of the pH of the water in the biological treatment tank 10, and therefore, the amount of nutrient added can be optimized regardless of the pH of the water to be treated. In addition, the solubility of carbon dioxide in water depends on the water temperature, but if the solubility of carbon dioxide is changed, the concentration of carbon dioxide in the gas discharged from the water in the biological treatment tank 10 is also changed. Therefore, when there is a change in the water temperature in the biological treatment tank 10, the water temperature is measured in the water quality measuring unit 33 in addition to the pH, and the addition amount of the nutrient can be controlled based on the water temperature in addition to the carbon dioxide concentration, the air volume, and the pH.
In the second embodiment, a plurality of biological treatment tanks for biological treatment can be connected in series to obtain treated water from which organic substances are highly removed. Fig. 6 shows a drainage treatment apparatus for performing aerobic treatment-based drainage treatment in the same manner as the drainage treatment apparatus shown in fig. 4 and 5, in which a plurality of biological treatment tanks 10 are provided in series, that is, in a plurality of stages. When the biological treatment tank 10 is provided with a plurality of stages of 2 or more stages, the concentration of carbon dioxide in the gas discharged from the biological treatment tank is measured in the biological treatment tank 10 of the foremost stage, the air volume of the air supplied to the biological treatment tank is measured, the BOD concentration value of the water to be treated is calculated from the carbon dioxide concentration and the air volume of the air, and the amount of the nutrient to be added to the water to be treated supplied to the biological treatment tank can be controlled based on the BOD concentration value. In this case, the pH of the water in the biological treatment tank 10 at the forefront stage can be measured, and the amount of nutrient added to the water to be treated can be controlled based on the carbon dioxide concentration, the air volume and the pH. Therefore, in the drainage treatment device shown in fig. 6, the carbon dioxide concentration sensor 31, the air gauge 32, and the water quality measuring unit 33 are provided only in the biological treatment water tank 10 at the forefront stage, and the nutrient solution from the nutrient tank 21 is added to the water to be treated in the inlet pipe 13 connected to the biological treatment water tank 10 at the forefront stage. The control device 40 calculates the BOD concentration value of the water to be treated from the measured values of the carbon dioxide concentration sensor 31, the air gauge 32, and the water quality measuring unit 33, and controls the pump 23 for supplying the nutrient solution based on the BOD concentration value.
In the case where the biological treatment tanks 10 are arranged in series at 2 or more stages, as described above, the biological treatment can be advanced in the biological treatment tanks 10 after the 2 nd stage without adding any nutrient to the water supplied to the biological treatment tanks 10 after the 2 nd stage, and the overall treatment performance of the drainage treatment apparatus can be maintained. Therefore, the measurement of the carbon dioxide concentration, the air volume, and the pH may not be performed for the biological treatment tanks of the 2 nd and subsequent stages.
According to the first and second embodiments of the present invention described above, in the biological treatment of organic wastewater, it is possible to stably determine the optimal amount of the nutrient to be added to the water to be treated as the organic wastewater.
Third embodiment
Next, a third embodiment of the present invention will be described. The third embodiment relates to calculation of an operation index for controlling biological treatment when biological treatment using microorganisms is performed on organic wastewater in a biological treatment tank to decompose and remove organic substances. Fig. 7 shows a drainage treatment device according to a third embodiment, which includes a calculation device for calculating an operation index.
The drainage treatment device shown in fig. 7 includes a fluidized bed type biological treatment tank 10 for storing water to be treated and performing biological treatment of the water to be treated under aerobic conditions. In the third embodiment, the water to be treated is organic wastewater flowing into the biological treatment tank 10. The treated water from which the organic matter is decomposed and removed by the biological treatment is discharged from the biological treatment tank 10. As in the case of the first embodiment, the biological treatment tank 10 shown in fig. 7 is filled with the carrier 11, and a gas dispersing device 12 for blowing air into the biological treatment tank 10 for supplying oxygen is provided at the bottom of the biological treatment tank 10. An inlet pipe 13 for supplying water to be treated to the biological treatment tank 10 is connected to the biological treatment tank 10. A gas pipe 14 for supplying air to the air diffusing device 12 is connected to the air diffusing device 12, and a blower 15 for supplying air is provided in the gas pipe 14. Examples of the carrier 11 that can be used here include plastic carriers, sponge carriers, gel carriers, and the like, and among them, sponge carriers are preferably used from the viewpoints of cost and durability. The biological treatment tank 10 may be provided with a stirring device for stirring the carrier 11.
In the drainage treatment device shown in fig. 7, an operation index for controlling the biological treatment is calculated based on the treatment amount of a specific gas discharged from the water in the biological treatment tank 10 by the biological treatment and 1 or more measurement values related to the water quality of the water in the biological treatment tank 10. Therefore, the biological treatment tank 10 is provided with: a gas measurement unit 36 that measures the amount of treatment of a specific gas discharged from the water in the biological treatment tank 10; and a water quality measuring unit 33 for measuring the water quality of the water in the biological treatment tank 10. The biological treatment tank 10 is covered with the cover 16, and the gas measuring unit 36 is provided in a gas phase portion in the biological treatment tank 10, a pipe connected to the gas phase portion, and the like. Since dew condensation of the gas measuring unit 36 needs to be avoided, when the gas measuring unit 36 is provided in a pipe, heat preservation of the pipe and the like can be achieved, and the moisture separator can be disposed at a position immediately in front of the gas measuring unit 36. In addition, a desulfurization device or the like for removing corrosive gas may be provided. In the case where the biological treatment tank 10 is an open system, in order to reduce the influence of the external air in the measurement result, a tubular pipe or the like is inserted under the water surface in order to minimize the open portion in the upper portion of the biological treatment tank 10, and the gas measurement portion 36 is disposed at a position on the water surface in the pipe.
As the treatment amount of the specific gas discharged in the biological treatment, for example, the concentration (unit is, for example, ppm or mL/m 3 ) At least one of a flow rate (in mL/h, for example) of the specific gas obtained by multiplying a concentration of the specific gas by a flow rate of all the gas discharged from the water in the biological treatment tank 10 by the biological treatment, a volume (in mL, for example) of the specific gas obtained by multiplying a given time or an accumulated time by the flow rate, a partial pressure (in Pa, for example) of the specific gas calculated from the concentration of the specific gas and a pressure of the gas discharged from the water in the biological treatment tank 10 by the biological treatment, and the like. In addition to the volume and partial pressure, a mass (in kg, for example) and a mass (in mol) can be arbitrarily used. Various gases can be considered as the gas that can be generated in the biological treatment, but in the case where the biological treatment is an aerobic treatment, the gas measurement unit 36 preferably measures the amount of carbon dioxide that is the final product when the organic matter is decomposed by the aerobic treatment. In the case of measuring the concentration of carbon dioxide, for example, an optical, electrochemical or semiconductor carbon dioxide concentration sensor can be used as the gas measuring unit 36, but a sensor based on a non-dispersive infrared absorption method (NDIR) is particularly preferably used. The measurement of the throughput of the gas can be carried out manually (manual) or on-line. In the case of measuring the flow rate as the amount of gas to be processed, the flow rate sensor may be an ultrasonic type, an electromagnetic type, a coriolis type, a kalman vortex type, a float type, a thermal type, an impeller type, a differential pressure type, or the like.
In the third embodiment, examples of the water quality of the water in the biological treatment tank 10 include pH (hydrogen ion concentration index), water temperature, dissolved oxygen concentration (DO), oxidation-reduction potential (ORP), conductivity, turbidity, and the like, as items measured by the water quality measuring unit 33. The water quality measuring unit 33 is configured to be able to measure 1 or more items including at least one of pH, water temperature, and ORP among these items. As described above, it is considered that the relationship between the pH and the carbon dioxide concentration in the gas discharged from the water in the biological treatment tank 10 by the aerobic treatment, that is, the biological treatment is particularly large. Further, since the solubility water temperature of carbon dioxide varies depending on the water temperature, the water temperature is also greatly related to the carbon dioxide concentration in the gas discharged from the water in the biological treatment tank 10. The amount of oxygen and the oxidation-reduction tendency of the water in the biological treatment tank 10 can be grasped from the ORP and the dissolved oxygen concentration, and the correlation between the ORP and the dissolved oxygen concentration and the concentration of the discharged carbon dioxide is large. The measurement in the water quality measuring section 33 may be performed manually or on-line.
Although there is also an online TOC concentration meter that measures the Total Organic Carbon (TOC) concentration in water online, the online TOC concentration meter is provided with a thin piping for introducing a small amount of sample water into the measuring device, and is prone to clogging and unstable in measurement value. On the other hand, the carbon dioxide concentration sensor and the gas flow sensor measure the carbon dioxide concentration sensor and the gas flow sensor without contacting with water, and thus the stability of the measured values is very high. The water quality measuring unit 33 for measuring pH, water temperature, ORP, and the like is also a sensor immersed in the biological treatment tank 10, and thus the stability of the measured value is high.
In the drainage treatment device shown in fig. 7, an operation index concerning water supplied to the biological treatment tank 10, that is, water to be treated, is calculated from the value of the treatment amount of the gas measured by the gas measuring unit 36 and the value of the water quality measured by the water quality measuring unit 33. The calculated operation index is used, for example, to determine the amount of nutrients added to the water to be treated or the water in the biological treatment tank 10, or to determine the amount and flow rate of air or oxygen blown into the biological treatment tank 10. The drainage treatment device is provided with an arithmetic device 50 for calculating the operation index. The measured values are input from the gas measurement unit 36 and the water quality measurement unit 33 to the arithmetic device 50, and the arithmetic device 50 calculates an operation index from the measured value in the gas measurement unit 36 and the measured value in the water quality measurement unit 33 based on a relation obtained in advance between the amount of treatment of the gas discharged from the water in the biological treatment tank 10, the water quality of the water in the biological treatment tank 10, and the water quality of the water to be treated. The relation between the concentration of gas, the water quality and the operation index, which is obtained in advance, is expressed by a model or a relational expression. The creation of the model and the relation will be described later. The operation index calculated by the arithmetic device 50 is an operation index related to the water to be treated. The operation index related to the water to be treated is preferably at least one of an organic matter concentration, a nitrogen concentration, a phosphorus concentration, a dissolved oxygen concentration, and an ORP in the water to be treated, and more preferably at least one of a Total Organic Carbon (TOC) concentration, a Biochemical Oxygen Demand (BOD), and a Chemical Oxygen Demand (COD) in the water to be treated. TOC, BOD and COD are all indicators showing the concentration of organic matters in the water to be treated.
Fig. 8 is a flowchart showing a procedure of a process of determining the organic matter concentration of the water to be treated in the drainage treatment device shown in fig. 7. First, in step 101, the gas measurement unit 36 measures the throughput (e.g., concentration) of gas (e.g., carbon dioxide) discharged from the water in the biological treatment tank 10, and in step 102, the water quality measurement unit 33 measures the water quality (e.g., pH, water temperature, or ORP) of the water in the biological treatment tank 10. In fig. 8, step 102 is depicted as being performed after the performance of step 101, but step 102 may be performed before step 101 or both steps 101 and 102 may be performed simultaneously. Then, in step 103, the operation device 50 substitutes the amount of gas processed in step 101 and the water quality obtained in step 102 into the model and the relational expression stored in the operation device 50, thereby calculating an operation index (for example, organic matter concentration) related to the water to be processed.
Next, creation of a model or a relational expression used in the drainage treatment device shown in fig. 7 will be described. The model or the relational expression is created by examining in advance the relationship between the amount of gas generated by the water in the biological treatment tank 10, the water quality in the biological treatment tank 10, and the water quality related to the operation index of the water to be treated flowing into the biological treatment tank 10. In order to create a model and a relational expression, the drainage treatment apparatus shown in fig. 7 is provided with a water quality measurement unit 34 for measuring the water quality of water to be treated as an operation index, for the inlet pipe 13 for supplying water to be treated to the biological treatment tank 10. The water quality measured by the water quality measurement unit 34 is preferably at least one of an organic matter concentration, a nitrogen concentration, a phosphorus concentration, a dissolved oxygen concentration, and an ORP, and more preferably any one of TOC, BOD, and COD as an organic matter concentration. The arithmetic device 50 creates a model and a relational expression based on the water quality of the water to be treated measured by the water quality measuring unit 34, the measured value of the gas measuring unit 36 at the time of measuring the water quality of the water to be treated, and the measured value of the water quality measuring unit 33. A combination of a measured value of the treatment amount of a certain amount (for example, several tens to several hundreds of sets) of gas, a measured value of the water quality of the water in the biological treatment tank 10 measured by the water quality measuring section 33, and a measured value of the water quality of the water to be treated measured by the water quality measuring section 34 is acquired, and based on the data of these sets, multiple regression analysis (in the case of deriving a relational expression) or learning of a neural network (in the case of creating a model) is performed. Further, since the amount of gas to be treated and the water quality vary depending on the structure and size of the biological treatment tank 10, the size of the gas phase portion in the biological treatment tank 10, the type of biological treatment, and the like, models and relationships may be created for each biological treatment tank 10. Further, since the relationship between the water quality of the water to be treated and the measured amount of gas and the water quality of the water in the biological treatment tank 10 may vary depending on the type and source of the water to be treated, a model may be created for each type and source of the water to be treated.
Fig. 9 shows an example of a database of a set of measured values of the amount of treatment of gas stored, measured values of the water quality of water in the biological treatment tank 10, and measured values of the water quality of the water to be treated. Here, the carbon dioxide concentration is measured as the treatment amount of the gas, the water temperature and pH are measured as the water quality of the water in the biological treatment tank 10, and the TOC concentration is measured as the water quality of the water to be treated. Then, by performing multiple regression analysis on such a database, a relational expression for calculating the organic matter concentration as an operation index shown below is obtained.
C＝b 1 X+b 2 Y+b 0
Here, C is the organic matter concentration as an operation index, X is the gas concentration as the treatment amount of the gas, Y is the water quality of the water in the biological treatment tank 10, b 0 、b 1 、b 2 Is a constant obtained by multiple regression analysis.
When generating a model based on the neural network, the neural network may be learned by supervised learning, with the processing amount Xn of the gas and the water quality Yn as input values (Xn, yn) and the organic matter concentration Cn as an operation index as output values (Cn), based on the database shown in fig. 9. Using a model based on a neural network that is suitably learned provides a more accurate concentration of organic matter as an operation index than a relational expression based on multiple regression analysis.
Fig. 10 shows a drain treatment apparatus in which a mechanism for adding a nutrient to water to be treated is added to the drain treatment apparatus shown in fig. 7. For example, in biological treatment such as aerobic treatment, in order to maintain the decomposition activity and the growth of microorganisms, nutrients are required, and when nutrients in the water to be treated in the biological treatment tank 10 are insufficient, it is necessary to add nutrients to the water to be treated in the biological treatment tank 10 or in a stage preceding the biological treatment tank 10. In the drainage treatment device shown in fig. 10, a nutrient tank 21 for storing a nutrient solution (i.e., nutrient solution) is provided, and the nutrient tank 21 and the inlet pipe 13 are connected via a nutrient solution pipe 22. The pump 23 for supplying the nutrient solution is provided in the nutrient solution piping 22. Therefore, in this drain treatment apparatus, it is possible to add a nutrient to the water to be treated flowing through the inlet pipe 13 and supplied to the biological treatment tank 10, and the amount of the nutrient to be added to the water to be treated can be controlled by controlling the pump 23. As the nutrient substance, the substances described in the first embodiment can be used.
Next, control of the amount of nutrient added to the drainage treatment device shown in fig. 10 will be described. It is recommended that the amount of nutrient (nutrient salt and trace metal) added to the water to be treated in the biological treatment tank is proportional to the concentration of organic matter in the water to be treated. For example, it is recommended to use BOD as an operation index, and the addition amount of nitrogen (N) and phosphorus (P) in the aerobic treatment is defined as BOD on a mass basis: n: p=100: 5:1. accordingly, in the drainage treatment device shown in fig. 10, the discharge amount control and the operating time control of the pump 23 are performed based on the operation index obtained in the operation device 50, and the presence or absence of the addition of the nutrient to the water to be treated and the addition amount thereof are controlled. Thus, even if the concentration of organic substances (e.g., BOD) in the water to be treated is not measured, the nutrient can be added to the water to be treated in an optimal amount.
As described in the first embodiment, when the gas is blown into the biological treatment tank 10, it is necessary to determine the amount of the nutrient to be added by modifying the concentration of carbon dioxide in the gas. Fig. 11 shows a drain treatment apparatus modified according to the concentration of carbon dioxide blown into the biological treatment tank 10 in this way. The drainage treatment device shown in fig. 11 is the same drainage treatment device as that shown in fig. 7, but is different from the drainage treatment device shown in fig. 7 in that a carbon dioxide concentration sensor 35 is provided in the gas pipe 14 at a position on the outlet side of the blower 15 in order to measure the carbon dioxide concentration in the blown-in air. The measured value of the carbon dioxide concentration sensor 35 provided in the gas pipe 14 is also sent to the arithmetic unit 50. The computing device 50 obtains the difference between the measured value of the carbon dioxide concentration sensor 35 and the measured value of the gas measuring unit 36, applies the difference and the measured value obtained by the water quality measuring unit 33 to a model, calculates the BOD of the water to be treated, and controls the pump 23 based on the BOD.
According to the third embodiment of the present invention described above, when the organic wastewater is treated by biological treatment, an accurate operation index for controlling biological treatment can be quickly obtained, and thus, for example, when a nutrient is added to water to be treated which is supplied to a biological treatment tank and flows in, an optimum addition amount based on the operation index can be set.
Examples (example)
The present invention will be described in further detail with reference to examples and comparative examples.
Example A and comparative example A
Example a and comparative example a will be described. Examples a and comparative examples a are examples and comparative examples corresponding to the first embodiment. Each example and comparative example are distinguished by giving a branch number.
[ test conditions A1]
First, test conditions common to examples A-1, A-2 and A-3 and comparative examples A-1 and A-2 will be described. Biological treatment by aerobic treatment of the water to be treated as organic wastewater was performed using a primary biological treatment tank having a volume of 19L. The aerobic microorganisms were supported on a sponge-like carrier composed of a hydrophobic polyurethane resin, and the sponge-like carrier was filled into the biological treatment tank at a bulk volume of 20% with respect to the volume of the biological treatment tank. The residence time in the biological treatment tank was set to 18 hours. As the water to be treated, a drain containing isopropyl alcohol was used. The BOD concentration in the treated water is about 900mg/L (the standard concentration), the nitrogen (N) concentration in the treated water is 2mg/L or less, and the phosphorus (P) concentration is 0.1mg or less. BOD volume load at the time of biological treatment was about 1kg/m 3 The water temperature is about 20 ℃, the concentration of Dissolved Oxygen (DO) of water in the biological treatment water tank is more than 2mg/L, and the pH of the water in the biological treatment water tank is 6.0-7.5.
Nutrient salts (nitrogen (N) and phosphorus (P)) are added to the water to be treated to sufficiently increase BOD: n: p is 100:5:1 monitoring the carbon dioxide concentration discharged from the water in the biological treatment tank, the pH of the water in the biological treatment tank, and the concentration of dissolved oxygen. The BOD concentration in the treated water was intentionally changed from 100% to 30% and 60% of the reference concentration, and this monitoring was repeatedly performed. The BOD concentration of the water to be treated can be calculated with high accuracy, which means that the accuracy of the nutrient addition control is high.
Comparative example A-1
Calculating BOD concentration based on carbon dioxide concentrationFor the carbon dioxide concentration and each BOD concentration, a determination coefficient R is calculated by unitary regression analysis 2 The result was 0.840.
Example A-1
The determination coefficient R is calculated by multiple regression analysis for the carbon dioxide concentration, pH and each BOD concentration by calculating the BOD concentration from the carbon dioxide concentration and the pH of the water in the biological treatment tank 2 As a result, it was 0.991. Compared with the case of using only the carbon dioxide concentration, it is found that the accuracy of calculating the BOD concentration is greatly improved by using the carbon dioxide concentration and the pH.
Examples A-2
The BOD concentration is calculated based on the carbon dioxide concentration and the pH of the water in the biological treatment tank, and the determination coefficient R is calculated by neural network analysis for the carbon dioxide concentration, pH and each BOD concentration 2 As a result, it was 0.996. It is known that the calculation accuracy is further improved by using the neural network model.
[ error variance in neural network analysis ]
The carbon dioxide concentration, pH and dissolved oxygen concentration were monitored according to the test conditions A1. Thus, a plurality of data sets were obtained in which the input was set to the carbon dioxide concentration, pH and dissolved oxygen concentration, and the output was set to the BOD concentration. Therefore, regarding all the acquired data sets, a specific one of the data sets is used as test data, the other data sets are used as training data, and a model is created by neural network analysis, so that an error between an output value when the test data is input to the model and an actual measured value of BOD of the water to be treated is obtained. This operation is repeatedly performed on all data sets as cross validation (cross validation), and the variance of the obtained error is calculated and evaluated. The lower the error variance value is, the more the BOD concentration of the water to be treated can be appropriately calculated.
Comparative example A-2
The error variance was obtained for the dataset using only the carbon dioxide concentration as input, resulting in 290.
Examples A-3
Regarding the data set using the carbon dioxide concentration and the dissolved oxygen concentration as inputs, the error variance was found, and the error variance was improved to 61. Regarding the data set using the carbon dioxide concentration and pH as inputs, the error variance was found to be 11. Regarding the data set using the carbon dioxide concentration, pH and dissolved oxygen concentration as inputs, the error variance was found to be 22.
[ test conditions A2]
Test conditions A2 are test conditions common to examples A-4, A-5 and comparative example A-3. In the test condition A1, the biological treatment tank was filled with the sponge-like carrier at a bulk volume of 30% relative to the volume of the biological treatment tank, the retention time in the biological treatment tank was 8 hours, and the water temperature was varied to 20 to 30 ℃. BOD volume load at the time of biological treatment was about 3kg/m 3 The pH of the water in the biological treatment tank is 5.6-7.8. The carbon dioxide concentration discharged from the water in the biological treatment tank, the pH and the water temperature of the water in the biological treatment tank are monitored.
Comparative example A-3
Calculating BOD concentration from carbon dioxide concentration, and calculating determination coefficient R by unitary regression analysis for carbon dioxide concentration and each BOD concentration 2 The result was 0.770.
Examples A-4
Calculating BOD according to the carbon dioxide concentration and the water temperature in the biological treatment water tank, and analyzing and calculating a determination coefficient R by a neural network according to the carbon dioxide concentration, the water temperature and the BOD concentrations 2 The result was 0.927. Compared with the case of using only the carbon dioxide concentration, it is found that the accuracy of calculating the BOD concentration is greatly improved by using the carbon dioxide concentration and the water temperature.
Examples A-5
Calculating BOD according to carbon dioxide concentration, water temperature and pH in biological treatment water tank, and calculating determination coefficient R by neural network analysis for carbon dioxide concentration, water temperature, pH and BOD concentration 2 As a result, it was 0.926. Compared with the case of using only the carbon dioxide concentration, it is found that the accuracy of calculating the BOD concentration is greatly improved by using the carbon dioxide concentration, the water temperature and the pH.
As is clear from comparative example a and example a described above, the addition amount of the nutrient can be optimized by calculating the BOD concentration of the water to be treated using a model created in advance using 1 or more measured values related to the water quality of the water in the biological treatment tank in addition to the carbon dioxide concentration.
Example B and comparative example B
Example B and comparative example B will be described. Examples B and comparative examples B are examples and comparative examples corresponding to the second embodiment. Each example and comparative example are distinguished by giving a branch number. First, test conditions common to example B and comparative example B will be described.
Biological treatment by aerobic treatment of the water to be treated as organic wastewater was performed using a primary biological treatment tank having a volume of 19L as shown in FIG. 5. The aerobic microorganisms were supported on a sponge-like carrier composed of a hydrophobic polyurethane resin, and the sponge-like carrier was filled into the biological treatment tank at a volume of 20% of the bulk volume with respect to the volume of the biological treatment tank. The residence time in the biological treatment tank was set to 18 hours. As the water to be treated, a drain containing isopropyl alcohol was used. The BOD concentration in the treated water is about 900mg/L (the standard concentration), the nitrogen (N) concentration in the treated water is 2mg/L or less, and the phosphorus (P) concentration is 0.1mg or less. BOD volume load at the time of biological treatment was about 1kg/m 3 The water temperature is about 20 ℃, the dissolved oxygen concentration of the water in the biological treatment water tank is more than 2mg/L, and the pH value of the water in the biological treatment water tank is 6.0-7.5. For air dispersion, air is supplied to the biological treatment tank at a flow rate of 3 to 5L/min.
Nutrient salts (nitrogen (N) and phosphorus (P)) are added to the water to be treated to sufficiently increase BOD: n: p is 100:5:1 and monitoring the concentration of carbon dioxide discharged from the water in the biological treatment tank and the pH of the water in the biological treatment tank. The BOD concentration in the treated water was intentionally changed from 100% to 30% and 60% of the reference concentration, and this monitoring was repeatedly performed. The BOD concentration of the water to be treated can be calculated with high accuracy, which means that the accuracy of the nutrient addition control is high.
Comparative example B-1
Calculating BOD concentration of the treated water based on the carbon dioxide concentration, and calculating a determination coefficient R by unitary regression analysis for the carbon dioxide concentration and each BOD concentration 2 As a result, it was 0.39.
Example B-1
Calculating BOD concentration of the water to be treated based on the carbon dioxide concentration and the air volume, and calculating a determination coefficient R by multiple regression analysis for the carbon dioxide concentration, the air volume and each BOD concentration 2 The result was 0.82. Compared with the case of using only the carbon dioxide concentration, it is found that the accuracy of calculating the BOD concentration is greatly improved by using the carbon dioxide concentration and the air volume.
Example B-2
Calculating BOD concentration of the water to be treated from the carbon dioxide concentration and the air volume, obtaining product of the measured value of the carbon dioxide concentration and the measured value of the air volume, and calculating determination coefficient R by unitary regression analysis for each BOD concentration 2 As a result, it was 0.83. It is found that the accuracy of calculating the BOD concentration is further improved by using the product of the carbon dioxide concentration and the air volume.
Comparative example B-2
The BOD concentration of the water to be treated is calculated based on the carbon dioxide concentration and pH, and the determination coefficient R is calculated by multiple regression analysis for the carbon dioxide concentration, pH and each BOD concentration 2 The result was 0.40.
Example B-3
The BOD concentration of the water to be treated is calculated based on the carbon dioxide concentration, the air quantity and the pH, and the determination coefficient R is calculated by multiple regression analysis for the carbon dioxide concentration, the air quantity, the pH and the BOD concentrations 2 As a result, it was 0.89. Compared with the case of using the carbon dioxide concentration and the pH, it is found that the accuracy of calculating the BOD concentration is greatly improved by using the air volume in addition to the carbon dioxide concentration and the pH.
Example B-4]
Calculating BOD concentration of the treated water based on the carbon dioxide concentration, the air volume and the pH, obtaining the product of the measured value of the carbon dioxide concentration and the measured value of the air volume, and calculating the product, the pH and each BOD concentration by multiple regression analysisDetermining the coefficient R 2 The result was 0.96. In comparison with the case of using the carbon dioxide concentration and the pH, it is found that the calculation accuracy of the BOD concentration is greatly improved by using the product of the measured value of the carbon dioxide concentration and the measured value of the air volume.
As is clear from comparative example B and example B described above, the addition amount of the nutrient can be optimized by calculating the BOD concentration of the water to be treated using a model created in advance using at least the air volume in addition to the carbon dioxide concentration.
Example C and comparative example C
Example C and comparative example C will be described. Examples C and comparative examples C are examples and comparative examples corresponding to the third embodiment. Each example and comparative example are distinguished by giving a branch number. First, test conditions common to example C and comparative example C will be described.
Biological treatment by aerobic treatment of the water to be treated as organic wastewater was performed using a primary biological treatment tank having a volume of 19L. The aerobic microorganisms were supported on a sponge-like carrier composed of a hydrophobic polyurethane resin, and the sponge-like carrier was filled into the biological treatment tank at a bulk volume of 30% with respect to the volume of the biological treatment tank. The residence time in the biological treatment tank was set to 8 hours. As the water to be treated, isopropanol-containing drainage was used. The concentration of nitrogen (N) in the treated water is 2mg/L or less, and the concentration of phosphorus (P) is 0.1mg or less. The pH of the water in the biological treatment water tank is 5.6-7.8. The air flow rate during ventilation was set to 10L/min, but it actually varied between 9.7 and 10.3L/min.
The concentration of carbon dioxide discharged from the water in the biological treatment tank, the pH, the water temperature and the ORP of the water in the biological treatment tank are monitored by adding a nutrient salt (nitrogen (N) and phosphorus (P) to the water to be treated, and TOC in the water to be treated is varied in the range of 50mg/L to 350mg/L, and such monitoring is repeatedly performed.
Comparative example C-1
Unitary regression analysis using respective measurements of carbon dioxide concentration and TOC concentration, derived fromThe carbon dioxide concentration was used to determine the relationship between TOC concentration. Then, the TOC concentration is estimated from the carbon dioxide concentration using the relational expression, and a determination coefficient R for the measured TOC concentration is calculated 2 The result was 0.770.
Example C-1
Multiple regression analysis was performed using the respective measured values of the carbon dioxide concentration, the water temperature, and the TOC concentration, and a relational expression was derived in which the TOC concentration was obtained from the carbon dioxide concentration and the water temperature. Then, the TOC concentration is estimated from the carbon dioxide concentration and the water temperature using the relational expression, and a determination coefficient R for the TOC concentration measured and calculated 2 As a result, 0.801.
Example C-2
Multiple regression analysis was performed using the respective measured values of the carbon dioxide concentration, ORP and TOC concentration, and a relational expression was derived in which TOC concentration was obtained from the carbon dioxide concentration and ORP. Then, the TOC concentration is estimated from the carbon dioxide concentration and ORP using the relational expression, and a determination coefficient R for the TOC concentration measured and calculated 2 The result was 0.836.
Example C-3
Multiple regression analysis was performed using the respective measured values of carbon dioxide concentration, pH and TOC concentration, and a relational expression for obtaining TOC concentration from carbon dioxide concentration and pH was derived. Then, the TOC concentration is estimated from the carbon dioxide concentration and pH using the relational expression, and a determination coefficient R for the measured TOC concentration is calculated 2 The result was 0.858.
Example C-4
Multiple regression analysis was performed using the respective measured values of carbon dioxide concentration, water temperature, pH and TOC concentration, and a relational expression was derived in which TOC concentration was obtained from carbon dioxide concentration, water temperature and pH. Then, the TOC concentration is estimated from the carbon dioxide concentration, the water temperature and the pH using the relational expression, and a determination coefficient R for the TOC concentration measured and calculated 2 As a result, it was 0.859.
Example C-5
Performing supervised learning with each measured value of carbon dioxide concentration and water temperature as input and measured value of TOC concentration as outputA neural network-based model is constructed. Calculating a determination coefficient R of TOC concentration from the carbon dioxide concentration and the water temperature by using the learned model 2 The result was 0.927.
Example C-6
A model based on a neural network is constructed by performing supervised learning in which each measured value of carbon dioxide concentration and ORP is input and a measured value of TOC concentration is output. Calculating a determination coefficient R of TOC concentration from the carbon dioxide concentration and ORP using the learned model 2 The result was 0.933.
Example C-7
A model based on a neural network is constructed by performing supervised learning in which each measured value of carbon dioxide concentration and pH is input and the measured value of TOC concentration is output. Calculating a determination coefficient R of TOC concentration from the carbon dioxide concentration and pH using the learned model 2 The result was 0.927.
Example C-8
A neural network-based model is constructed by performing supervised learning in which measured values of carbon dioxide concentration, water temperature, and pH are input and measured values of TOC concentration are output. Calculating a determination coefficient R of TOC concentration from carbon dioxide concentration, water temperature and pH using the learned model 2 As a result, it was 0.926.
Example C-9]
A neural network-based model is constructed by performing supervised learning in which measured values of carbon dioxide concentration, ORP, water temperature, and pH are input and measured values of TOC concentration are output. Calculating a determination coefficient R of TOC concentration based on the carbon dioxide concentration, ORP and water temperature by using the learned model 2 The result was 0.949.
Examples C-10
The carbon dioxide concentration is multiplied by the ventilation flow rate to obtain the flow rate of carbon dioxide. The carbon dioxide flow, ORP and water temperature are processed And supervised learning with each measured value of pH as input and measured value of TOC concentration as output, to construct a neural network-based model. Calculating a determination coefficient R of TOC concentration based on the carbon dioxide flow rate, ORP and water temperature by using the learned model 2 As a result, it was 0.971.
(description of the reference numerals)
10. Biological treatment water tank
11. Carrier body
12. Air dispersing device
13. Inlet pipe
14. Gas piping
15. Blower fan
16. Cover for a container
21. Nutrient storage tank
22. Nutrient solution piping
23. Pump with a pump body
31. 35 carbon dioxide concentration sensor
32. Wind meter
33. Water quality measuring unit
34. Treated water quality measuring unit
36. Gas measuring part
40. Control device
50. An arithmetic device.
Claims (20)
1. A method for calculating an operation index, which is used when biological treatment is performed on organic wastewater in a biological treatment tank,
calculating the operation index based on a relation obtained in advance for a treatment amount of gas discharged from water in the biological treatment tank, a water quality of water in the biological treatment tank, and a water quality of water to be treated flowing into the biological treatment tank, from a measurement value of the treatment amount of gas and a measurement value of the water quality of water in the biological treatment tank,
The treatment amount of the gas is at least one of the concentration, flow rate, volume, pressure, and mass of the gas,
the water quality of the water in the biological treatment tank includes at least one of water temperature, pH and oxidation-reduction potential,
the operation index is at least one of an organic matter concentration, a nitrogen concentration, a phosphorus concentration, a dissolved oxygen concentration, and an oxidation-reduction potential in the water to be treated.
2. The method for calculating an operation index according to claim 1, wherein,
the relationship is represented by a neural network model obtained by learning a data set in which a measured value of the treatment amount of the gas and a measured value of the water quality of the water in the biological treatment tank are input values and the operation index is output values.
3. The method for calculating an operation index according to claim 1 or 2, wherein,
the gas is carbon dioxide.
4. A method for biologically treating organic wastewater, wherein the method comprises the steps of,
the operation index is calculated by the calculation method according to any one of claim 1 to 3,
and performing control according to the calculated operation index, and performing biological treatment of the water to be treated in the biological treatment tank.
5. A method for biologically treating organic wastewater in a biological treatment tank, comprising:
a first measurement step of measuring a carbon dioxide concentration in a gas discharged from water in the biological treatment tank;
a second measurement step of obtaining 1 or more measurement values related to the water quality of the water in the biological treatment tank; and
a control step of controlling the amount of nutrient added to the organic wastewater based on the measured value of the carbon dioxide concentration obtained in the first measurement step and the 1 or more measured values obtained in the second measurement step,
the drainage treatment method comprises the following steps: a calculation step of calculating an organic matter concentration of the organic wastewater based on the measured value of the carbon dioxide concentration obtained in the first measurement step and the 1 or more measured values obtained in the second measurement step,
the control step is a step of controlling the amount of nutrient added to the organic wastewater based on the organic matter concentration.
6. The drainage treatment method of claim 5, wherein,
the measured values obtained by the second measurement process include measured values of at least one of pH and water temperature.
7. The drainage treatment method of claim 5, wherein,
when a plurality of the biological treatment tanks are provided in series, the first measurement step and the second measurement step are performed on the biological treatment tank at the forefront stage, and in the control step, the amount of nutrient added to the organic wastewater supplied to the biological treatment tank at the forefront stage or the organic wastewater in the biological treatment tank at the forefront stage is controlled.
8. A method for biologically treating organic wastewater in a biological treatment tank, comprising:
a first measurement step of measuring a concentration of a specific gas in a gas discharged from the water in the biological treatment tank;
a second measurement step of measuring a flow rate of gas supplied to the biological treatment tank or a flow rate of gas discharged from the biological treatment tank; and
a control step of controlling the amount of nutrient added to the organic wastewater based on the measured value of the concentration obtained in the first measurement step and the measured value of the flow rate obtained in the second measurement step,
in the control step, the amount of nutrient added to the organic wastewater is controlled based on the measured value of the concentration and the measured value of the flow rate, or based on the organic matter concentration of the organic wastewater calculated from a value obtained by multiplying the measured value of the concentration and the measured value of the flow rate.
9. The drainage treatment method of claim 8, wherein,
the drainage treatment method comprises the following steps: a third measurement step of measuring the pH of the water in the biological treatment tank,
the specific gas is carbon dioxide and the specific gas is carbon dioxide,
in the control step, the amount of nutrient added to the organic wastewater is controlled based on the measured value of the concentration, the measured value of the flow rate, and the measured value of the pH obtained in the third measurement step.
10. The drainage treatment method of claim 8, wherein,
when a plurality of the biological treatment tanks are provided in series, the first measurement step and the second measurement step are performed on the biological treatment tank at the forefront stage, and in the control step, the amount of the organic wastewater supplied to the biological treatment tank at the forefront stage or the amount of the nutrient added to the organic wastewater in the biological treatment tank at the forefront stage is controlled.
11. A calculation device for calculating an operation index used when biological treatment is performed on organic wastewater by a biological treatment tank, comprising:
a gas measurement unit that measures a treatment amount of gas discharged from water in the biological treatment tank;
A water quality measuring unit that measures the water quality of the water in the biological treatment tank; and
an arithmetic unit that calculates the operation index from a measurement value in the gas measurement unit and a measurement value in the water quality measurement unit based on a relationship obtained in advance for a treatment amount of gas discharged from the water in the biological treatment tank, a water quality of the water in the biological treatment tank, and a water quality of water to be treated flowing into the biological treatment tank,
the treatment amount of the gas is at least one of the concentration, the flow rate, the volume, the pressure and the mass of the gas,
the water quality of the water in the biological treatment tank includes at least one of water temperature, pH and oxidation-reduction potential,
the operation index is at least one of an organic matter concentration, a nitrogen concentration, a phosphorus concentration, a dissolved oxygen concentration, and an oxidation-reduction potential in the water to be treated.
12. The computing device of claim 11, wherein,
the computing device further includes a water quality measurement unit for measuring the water quality of the water to be treated,
the arithmetic unit learns a neural network using a data set having the measured value of the gas measuring unit and the measured value of the water quality measuring unit as input values and the measured value of the water quality measuring unit to be treated as output values, and expresses the relationship using a neural network model obtained by learning.
13. The computing device of claim 11 or 12, wherein,
the gas is carbon dioxide.
14. A drainage treatment device for biological treatment of organic drainage, comprising:
the computing device of any one of claims 11 to 13; and
an adding unit and/or an air dispersing unit, wherein the adding unit adds nutrient substances to the water to be treated, the air dispersing unit disperses air in the biological treatment water tank,
at least one of the adding unit and the air dispersing unit is controlled according to the calculated operation index.
15. A drainage treatment device is provided with:
a biological treatment tank for biologically treating organic wastewater;
an adding unit that adds a nutrient to the organic wastewater;
a first measurement unit having a first sensor that measures a carbon dioxide concentration in a gas discharged from water in the biological treatment tank;
a second measurement unit that acquires 1 or more measurement values related to the water quality of the water in the biological treatment tank; and
a control unit that controls an addition amount of the nutrient added by the addition unit based on the carbon dioxide concentration value obtained by the first measurement unit and the 1 or more measurement values obtained by the second measurement unit,
The control unit calculates an organic matter concentration of the organic wastewater from the measured value of the carbon dioxide concentration obtained by the first measuring unit and the 1 or more measured values obtained by the second measuring unit, and controls an addition amount of the nutrient based on the organic matter concentration.
16. The drainage treatment device of claim 15 wherein,
the measured values acquired by the second measuring unit include measured values of at least one of pH and water temperature.
17. The drainage treatment device of claim 15 wherein,
a plurality of the biological treatment tanks are arranged in series,
the adding unit adds a nutrient to the organic wastewater supplied to the biological treatment tank of the foremost stage or to the organic wastewater in the biological treatment tank of the foremost stage,
the first measuring unit and the second measuring unit are provided for the biological treatment tank of the foremost stage.
18. A drainage treatment device is provided with:
a biological treatment tank for biologically treating organic wastewater;
an adding unit that adds a nutrient to the organic wastewater;
a first measurement unit that measures a concentration of a specific gas among gases discharged from water in the biological treatment tank;
A second measurement unit that measures a flow rate of gas supplied to the biological treatment tank or a flow rate of gas discharged from the biological treatment tank; and
a control unit that controls an addition amount of the nutrient added by the addition unit based on the measured value of the concentration obtained by the first measurement unit and the measured value of the flow rate obtained by the second measurement unit,
the control unit controls the addition amount of the nutrient based on the measured value of the concentration and the measured value of the flow rate, or based on the organic matter concentration of the organic wastewater calculated from a value obtained by multiplying the measured value of the concentration and the measured value of the flow rate.
19. The drainage treatment device of claim 18 wherein,
the drainage treatment device is provided with a third measuring unit for measuring the pH value of the water in the biological treatment water tank,
the specific gas is carbon dioxide and the specific gas is carbon dioxide,
the control unit controls the addition amount of the nutrient added to the organic wastewater based on the measured value of the concentration, the measured value of the flow rate, and the measured value of the pH obtained by the third measurement unit.
20. The drainage treatment device of claim 18 wherein,
a plurality of the biological treatment tanks are arranged in series,
the adding unit adds a nutrient to the organic wastewater supplied to the biological treatment tank of the foremost stage or to the organic wastewater in the biological treatment tank of the foremost stage,
the first measuring unit and the second measuring unit are provided for the biological treatment tank of the foremost stage.
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| JP2021081412A JP2022175195A (en) | 2021-05-13 | 2021-05-13 | Calculation method and calculation device of operation indicator, biological treatment method, and biological treatment apparatus |
| JP2021-081413 | 2021-05-13 | ||
| JP2021081413A JP2022175196A (en) | 2021-05-13 | 2021-05-13 | Wastewater treatment method and wastewater treatment device |
| JP2021-098016 | 2021-06-11 | ||
| JP2021098016A JP2022189442A (en) | 2021-06-11 | 2021-06-11 | Waste water treatment method and waste water treatment apparatus |
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001334285A (en) * | 2000-05-25 | 2001-12-04 | Japan Organo Co Ltd | Apparatus for biologically treating organic wastewater |
| JP2001347288A (en) * | 2000-06-05 | 2001-12-18 | Nippon Sanso Corp | Wastewater treatment apparatus and wastewater load detection method |
| KR20030066073A (en) * | 2002-02-04 | 2003-08-09 | 주식회사 에코아이티이십일 | BOD and COD prediction system of wastewater treatment plant effluent using Suspended Solids meter and software sensor technology |
| JP2008231745A (en) * | 2007-03-19 | 2008-10-02 | Toshiba Corp | Pump control unit |
| CN101625353A (en) * | 2009-03-06 | 2010-01-13 | 北京工商大学 | Soft measurement method of outflow water quality of sewage treatment and on-line intelligent detecting instrument |
| CN102503062A (en) * | 2011-11-23 | 2012-06-20 | 同济大学 | Method and device for online optimized control of operation of two-sludge denitrifying dephosphatation process |
| CN106399113A (en) * | 2016-12-21 | 2017-02-15 | 江南大学 | High density microalgae culture method in membrane photobioreactor using municipal wastewater |
| CN109516572A (en) * | 2019-01-10 | 2019-03-26 | 天津城建大学 | Novel denitrification of autotrophic organism combination unit and operating parameter method of adjustment |
| CN109734202A (en) * | 2019-03-12 | 2019-05-10 | 山鹰国际控股股份公司 | A method of judgement and processing anaerobic grain sludge poisoning |
| AU2020101377A4 (en) * | 2020-07-15 | 2020-08-20 | Expert 365 Pty Ltd | A process and device for on-line detection of chemical oxygen demand (cod) and biological oxygen demand (bod) in water |
-
2022
- 2022-05-05 TW TW111116901A patent/TW202306911A/en unknown
- 2022-05-06 CN CN202210484687.5A patent/CN115340173B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001334285A (en) * | 2000-05-25 | 2001-12-04 | Japan Organo Co Ltd | Apparatus for biologically treating organic wastewater |
| JP2001347288A (en) * | 2000-06-05 | 2001-12-18 | Nippon Sanso Corp | Wastewater treatment apparatus and wastewater load detection method |
| KR20030066073A (en) * | 2002-02-04 | 2003-08-09 | 주식회사 에코아이티이십일 | BOD and COD prediction system of wastewater treatment plant effluent using Suspended Solids meter and software sensor technology |
| JP2008231745A (en) * | 2007-03-19 | 2008-10-02 | Toshiba Corp | Pump control unit |
| CN101625353A (en) * | 2009-03-06 | 2010-01-13 | 北京工商大学 | Soft measurement method of outflow water quality of sewage treatment and on-line intelligent detecting instrument |
| CN102503062A (en) * | 2011-11-23 | 2012-06-20 | 同济大学 | Method and device for online optimized control of operation of two-sludge denitrifying dephosphatation process |
| CN106399113A (en) * | 2016-12-21 | 2017-02-15 | 江南大学 | High density microalgae culture method in membrane photobioreactor using municipal wastewater |
| CN109516572A (en) * | 2019-01-10 | 2019-03-26 | 天津城建大学 | Novel denitrification of autotrophic organism combination unit and operating parameter method of adjustment |
| CN109734202A (en) * | 2019-03-12 | 2019-05-10 | 山鹰国际控股股份公司 | A method of judgement and processing anaerobic grain sludge poisoning |
| AU2020101377A4 (en) * | 2020-07-15 | 2020-08-20 | Expert 365 Pty Ltd | A process and device for on-line detection of chemical oxygen demand (cod) and biological oxygen demand (bod) in water |
Non-Patent Citations (1)
| Title |
|---|
| 刘雨等.《生物膜法污水处理技术》.《生物膜法污水处理技术》,2000,(第1版),116. * |
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