JP2011045872A - Method and apparatus of cod concentration simulation in biological aerobic treatment of ammoniacal liquor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of COD simulation capable of estimating a COD concentration in treated water after biological aerobic treatment of ammoniacal liquor generated in a coke production process and an apparatus thereof. <P>SOLUTION: The method includes: an analysis step for measuring to analyze each known component concentration and soluble COD concentration contained in the ammoniacal liquor; a known component COD fraction step for determining the COD concentration of each known component from the analyzed value of each known component concentration; a step for determining a hardly decomposable COD concentration beforehand; a step for determining an unknown component COD concentration contained in the ammoniacal liquor; a step for setting the type and the concentration of microorganisms, and growth yield, saturation constant and maximum specific growth rate to be a stoichiometry parameter; a step for measuring the dissolved oxygen concentration; a step for calculating each known component COD concentration and unknown component COD concentration remaining in treated water from information obtained from each step by predetermined calculation; and a treated water COD concentration calculation step for calculating a remaining soluble COD concentration by adding the hardly decomposable COD concentration to each calculated remaining known component COD concentration and unknown component COD concentration. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a treatment of aqueous water generated in a coke production process, and more specifically to a COD concentration simulation method and apparatus in a biological aerobic treatment process.

  In recent years, restrictions on total COD in closed water areas have been on the rise, and countermeasures for sewage, industrial wastewater, and factory wastewater are urgently needed. In order to comply with the COD total amount regulation value, it is necessary to identify the causative substance and to predict how far the standard can be satisfied. Until now, in the sewerage field, sewage treatment methods have been taken by biological treatment processes such as activated sludge process. The operation management is often performed mainly based on the experience of the manager, and it is difficult to obtain a stable treated water quality. For example, when the influent water quality fluctuates, the operation conditions and operation amount to be changed differ for each sewage treatment plant.

Therefore, an activated sludge model (ASM) proposed by IWA (International Water Association) has been proposed as a water quality prediction and operation support tool that does not depend on the experience of the manager. The activated sludge model is mainly composed of the following procedures.
(1) The COD concentration of influent water is fractionated according to the properties of soluble inert organic substances, readily decomposable organic substances, floating inert organic substances, slow decomposable organic substances, etc., and each is set as a COD concentration-based variable.
(2) For each process such as heterotrophic growth and autolysis, a stoichiometry between variables and a reaction rate equation for the process are set.
(3) The parameters of the stoichiometric coefficient and the reaction rate constant are determined by an oxygen respiration rate test or calibration from measured data of water quality.
(4) A simulation is executed to calculate the biological treatment tank, the COD concentration of the treated water, and the like.
This activated sludge model has been proposed as a management tool, and a sewage treatment management system using the activated sludge model has been proposed. (For example, Patent Document 1)

  On the other hand, the low water generated in the coke production process is treated by a biological treatment process in the same manner as sewage. However, since the composition of the aqueduct is different from that of the sewage, there is no case where the activated sludge model is applied to the COD simulation method for predicting the biodegradability compound component concentration of this aquatic treatment process by applying the activated sludge model.

JP 2003-300093 A

Supervised by Ministry of Construction, Urban Bureau, Sewerage Department, Ministry of Health and Welfare, Public Health Department, Environment Department, Japan, Japan Sewerage Association, Sewerage Test Method, August 25, 1997 Shun Miso, activated sludge model, Japan, Environmental Newspaper Co., Ltd., January 31, 2005 J. et al. S. Cech, J. et al. Chudoba and P.M. Grau, Determination of Kinetic Constants of Activated Sludge Microorganisms, Water Science and Technology, Vol. 17, pp. 259-272, 1984

  An activated sludge model is generally used as a method for simulating water quality in biological aerobic treatment. However, there is no case where this model was applied to low water and chemical oxygen demand (COD) concentration of treated water was simulated. . The reason for this is that the activated sludge model is composed of multiple components that cannot be identified as COD main components, such as sewage, and is therefore classified into “easily degradable” and “hardly degradable” COD concentrations. Predicts only the COD concentration of influent wastewater and treated water during biological aerobic treatment. On the other hand, in wastewater composed of causative components that can identify COD main components such as low water, biodegradability is different for each component in the wastewater, so “easily degradable” and “hardly degradable” This is because the COD concentration of influent wastewater and treated water during biological aerobic treatment cannot be sufficiently predicted in a large classification.

  In the water quality simulation method in biological aerobic treatment (Japanese Patent Application No. 2008-292519), which is the prior application of the present inventors, the concentration of each of the identifiable causal components in the wastewater is determined by biological aerobic treatment. Although it is possible to simulate the concentration of each component in the treated water, the COD concentration in the treated water is not predicted.

  In addition, in biological aerobic treatment of aquatic water, fluctuations in the concentration and composition of inflowing aquatic water, and fluctuations in microbial concentration make it difficult to predict the quality of the treated water. .

  In the present invention, a new activated sludge that predicts the COD concentration of known and unknown treated water components in the aquatic water in the process of biological aerobic treatment of the aqueous water generated in the coke production process in the biological reaction tank. An object of the present invention is to provide a COD simulation method and apparatus capable of building a model and predicting the COD concentration in treated water after biological aerobic treatment.

  The present inventors have focused on the fact that biodegradability differs for each component of the aquatic water, targeting the aquatic water that is composed of a plurality of components whose components can be specified by chemical analysis or the like, such as the aquatic water. By fractionating the soluble COD concentration in the aquatic water (known component) COD concentration, unknown component COD concentration and persistent COD concentration, and further dividing the known component into each component The simulated aerobic treatment of known and unknown components and determining the COD concentration in the treated water by the sum of the known component COD concentration, the unknown component COD concentration, and the persistent COD concentration COD concentration simulation in the process of biological aerobic treatment in the biological reaction tank of ammonia, containing phenol, thiosulfuric acid and thiocyan, which are the main causative components of It was.

Specifically, the present invention includes the following [1] to [10].
[1] A COD concentration simulation method in a process of biologically aerobically treating aqueous water generated in a coke production process in a biological reaction tank using microorganisms,
An analysis step for measuring and analyzing the concentration of each known component and soluble COD concentration of phenol, thiosulfuric acid, and thiocyan contained in the aqueous solution flowing into the biological reaction tank;
Based on the correlation between each known component concentration and the COD concentration of COD _Cr , COD _Mn, or COD theoretical value, the analysis value of each known component concentration is converted into a COD concentration, thereby obtaining each known component concentration. A known component COD fractionation step for determining the COD concentration of each known component corresponding to
In advance, each of the remaining components of phenol, thiosulfuric acid, and thiocyan remaining in the treated water of the aerobic biologically aerobically treated in the biological reaction tank is measured and analyzed, and the remaining soluble COD concentration is measured and analyzed. Based on the correlation between each remaining known component concentration and the COD concentration of COD _Cr , COD _Mn or COD theoretical value, the COD concentration of each remaining known component corresponding to each remaining known component concentration is determined. A subtractive COD fractionation step for determining the subtractable COD concentration in advance by subtracting the total value of the COD concentrations of the remaining known components from the residual soluble COD concentration;
From the soluble COD concentration obtained in the analysis step, the total value of the COD concentration of each known component obtained in the known component COD fractionation step and the hardly decomposable COD concentration obtained in the hardly decomposable COD fractionation step Subtracting the unknown component fractionation step for determining the unknown component COD concentration contained in the water that flows into the biological reaction tank,
The types and concentrations of microorganisms that decompose phenol, thiosulfuric acid, thiocyanate, and unknown component COD, and the growth yield and reaction rate parameters for the phenol, thiosulfuric acid, thiocyanate, and unknown component COD that are stoichiometric parameters. A parameter setting step for setting a saturation constant and a maximum specific growth rate for the phenol, thiosulfuric acid, thiocyan and unknown component COD;
A dissolved oxygen concentration measuring step for measuring a dissolved oxygen concentration in the biological reaction tank;
Using the known component COD concentration, the unknown component COD concentration, the persistent COD concentration, the growth yield, the saturation constant, the maximum specific growth rate, the type and concentration of the microorganism, and the measured dissolved oxygen concentration Thus, by calculating the calculation formula (1), the remaining known component COD concentration and the remaining unknown component COD concentration in the treated water of the safe water after the biological aerobic treatment in the biological reaction tank are simulated. A calculation process to calculate
A treated water COD concentration calculation step of calculating the remaining soluble COD concentration in the treated water by adding the hardly decomposable COD concentration to the calculated remaining known component COD concentration and remaining unknown component COD concentration. A COD concentration simulation method in a biological aerobic treatment of an aqueous water characterized by comprising:

Where C _{i is the} concentration of each known component COD and the unknown component COD i is a serial number representing the type of each known component COD and unknown component COD P _ij is a stoichiometric parameter j is a serial number representing each process ρ _{j is a} reaction rate equation (Rate equation including reaction rate equation parameters)

[2] The parameter setting step includes:
(A) In the inflowing water and treated water, the soluble COD concentration, the phenol concentration, the thiosulfuric acid concentration, the thiocyanate concentration, the hardly decomposable COD concentration separately collected in time series in advance, and A method of determining by calibration using unknown component COD concentration and dissolved oxygen concentration,
(B) Using a batch test device that continuously measures the dissolved oxygen concentration using a dissolved oxygen meter, using the microorganisms in the biological reaction tank and the target components in the aqueous solution, oxygen consumption in the oxygen consumption rate test Set parameters using any of the methods determined from the time series data of rate data and soluble COD concentration, phenol concentration, thiosulfate concentration, thiocyan concentration, persistent COD concentration, unknown component COD concentration The method for simulating COD concentration in the biological aerobic treatment of safe water according to [1].

[3] In the hardly decomposable COD fractionation step, the microorganism in the biological reaction tank is reacted with the aqueous solution in place of the treated water of biological aerobic treatment in the biological reaction tank. The COD concentration in the biological aerobic treatment of an aqueous water according to [1] or [2], wherein the persistent COD concentration is determined in advance using the treated water after the batch test. Simulation method.

[4] The method according to any one of [1] to [3], wherein the steps are performed by including the phenol in the concentration of the unknown component COD and using the known component as thiosulfuric acid or thiocyan. COD concentration simulation method in biological aerobic treatment of Japanese aquatic water.

[5] Using the amount of the inflowing water, the known component COD concentration, the unknown component COD concentration, the time-dependent data of the persistent COD component concentration, and the volume of the biological reaction tank In the calculation step, by calculating the mass balance in conjunction with the calculation of the calculation formula (1), each remaining remaining in the treated water of the low water after the biological aerobic treatment in the biological reaction tank The COD concentration simulation method in the biological aerobic treatment of safe water according to any one of [1] to [4], wherein the component COD concentration and the remaining unknown component COD concentration are calculated by simulation.

[6] A COD concentration simulation device in a process of biologically aerobic treatment of aqueous water generated in a coke production process in a biological reaction tank using microorganisms,
Analytical means for measuring and analyzing the concentration of each known component and soluble COD concentration of phenol, thiosulfuric acid, and thiocyan contained in the aqueous solution flowing into the biological reaction tank;
Based on the correlation between each known component concentration and the COD concentration of COD _Cr , COD _Mn, or COD theoretical value, the analysis value of each known component concentration is converted into a COD concentration, thereby obtaining each known component concentration. A known component COD fractionation means for determining the COD concentration of each known component corresponding to
In advance, each of the remaining components of phenol, thiosulfuric acid, and thiocyan remaining in the treated water of the aerobic biologically aerobically treated in the biological reaction tank is measured and analyzed, and the remaining soluble COD concentration is measured and analyzed. Based on the correlation between each remaining known component concentration and the COD concentration of COD _Cr , COD _Mn or COD theoretical value, the COD concentration of each remaining known component corresponding to each remaining known component concentration is determined. And subtractable COD fractionating means for determining the persistent COD concentration in advance by subtracting the total COD concentration of each remaining known component from the remaining soluble COD concentration,
The total COD concentration of each known component obtained by the known component COD fractionation means from the soluble COD concentration obtained by the analysis means, and the hardly decomposable COD concentration obtained by the hardly decomposable COD fractionation means Subtracting the unknown component fractionation means for determining the unknown component COD concentration contained in the water that flows into the biological reaction tank,
The types and concentrations of microorganisms that decompose phenol, thiosulfuric acid, thiocyanate, and unknown component COD, and the growth yield and reaction rate parameters for the phenol, thiosulfuric acid, thiocyanate, and unknown component COD that are stoichiometric parameters. Parameter setting means for setting a saturation constant for the phenol, thiosulfuric acid, thiocyan and unknown component COD, and a maximum specific growth rate;
A dissolved oxygen concentration measuring means for measuring a dissolved oxygen concentration in the biological reaction tank;
Using the known component COD concentration, the unknown component COD concentration, the persistent COD concentration, the growth yield, the saturation constant, the maximum specific growth rate, the type and concentration of the microorganism, and the measured dissolved oxygen concentration Thus, by calculating the calculation formula (1), the remaining known component COD concentration and the remaining unknown component COD concentration in the treated water of the safe water after the biological aerobic treatment in the biological reaction tank are simulated. Calculating means for calculating
A treated water COD concentration calculating means for calculating the remaining soluble COD concentration in the treated water by adding the hardly decomposable COD concentration to the calculated remaining known component COD concentration and remaining unknown component COD concentration. A COD concentration simulation apparatus for biological aerobic treatment of aquatic water characterized by comprising:

Where C _{i is the} concentration of each known component COD and the unknown component COD i is a serial number representing the type of each known component COD and unknown component COD P _ij is a stoichiometric parameter j is a serial number representing each process ρ _{j is a} reaction rate equation (Rate equation including reaction rate equation parameters)

[7] The parameter setting means includes:
(A) In the inflowing water and treated water, the soluble COD concentration, the phenol concentration, the thiosulfuric acid concentration, the thiocyanate concentration, the hardly decomposable COD concentration separately collected in time series in advance, and An apparatus that uses unknown component COD concentration and dissolved oxygen concentration to determine by calibration,
(B) Using a batch test device that continuously measures the dissolved oxygen concentration using a dissolved oxygen meter, using the microorganisms in the biological reaction tank and the target components in the aqueous solution, oxygen consumption in the oxygen consumption rate test Set parameters using any one of the devices determined from the time series data of rate data and soluble COD concentration, phenol concentration, thiosulfate concentration, thiocyan concentration, persistent COD concentration, unknown component COD concentration The COD concentration simulation apparatus in the biological aerobic treatment of safe water according to [6].

[8] In the hardly decomposable COD fractionating means, the microorganisms in the biological reaction tank are reacted with the low water instead of the treated water of biological aerobic treatment in the biological reaction tank. The COD concentration in the biological aerobic treatment of an aqueous solution according to [6] or [7], wherein the persistent COD concentration is determined in advance using the treated water after the batch test. Simulation device.

[9] The method according to any one of [6] to [8], wherein the above means are implemented by including the phenol in the concentration of the unknown component COD and using the known component as thiosulfuric acid or thiocyan. COD concentration simulation device in biological aerobic treatment of Japanese aquatic water.

[10] Using time-lapse data of the inflowing aqueous solution, the known component COD concentration, the unknown component COD concentration, the persistent COD component concentration, and the volume of the biological reaction tank The calculation means calculates the material balance in combination with the calculation of the arithmetic expression (1), whereby each remaining known in the treated water of the aqueous solution after the biological aerobic treatment in the biological reaction tank is performed. The COD concentration simulation apparatus for biological aerobic treatment of safe water according to any one of [6] to [9], wherein the component COD concentration and the remaining unknown component COD concentration are calculated by simulation.

The effects produced by the present invention are as follows.
When the aqueous water generated in the coke production process is processed in the biological reaction tank, the known component concentration and the soluble COD concentration in the aqueous solution flowing into the biological reaction tank are measured, and the known component COD concentration is determined from the soluble COD concentration. By subtracting the persistent COD concentration and the unknown component COD concentration, and applying the activated sludge model, the treated water COD concentration after the aerobic treatment of the aquatic water can be predicted. That is, the COD concentration of treated water after biological aerobic treatment can be predicted by measuring the phenol concentration, thiosulfuric acid concentration, thiocyanate concentration, and soluble COD concentration in the inflowing water.

  In addition, according to the present invention, even if the contained component concentration and composition of the inflowing water are changed, the soluble COD concentration, the known component COD concentration, and the hardly decomposable COD concentration are analyzed and input to the simulation. Can be calculated. Further, since the microbial concentration is calculated, it is possible to calculate including the variation of the microbial concentration.

It is a conceptual diagram which shows the COD fraction based on this invention. It is a block diagram which shows the water quality simulation method of the biological treatment process of an aqueous water based on this invention. It is a figure which shows the correlation of a phenol concentration and COD _Mn . It is a block diagram of an oxygen consumption rate test apparatus. It is a figure which shows the simulation result in Example 1 which concerns on this invention. It is a figure which shows the time-dependent change of unknown component COD density | concentration in Example 2 which concerns on this invention. It is a figure which shows the simulation result in Example 2 which concerns on this invention. It is a figure which shows the simulation result in Example 3 which concerns on this invention. It is a block diagram which shows the water quality simulation method of the biological treatment process of an aqueous water in Example 4 which concerns on this invention. It is a figure which shows the simulation result in Example 4 which concerns on this invention.

  FIG. 1 is a diagram showing the low-water COD fraction in the present invention. COD is divided into solid COD that is not soluble in water and soluble COD. For example, by performing separation using filter paper, for example, what remains on the filter paper is obtained as solid COD, and the filtrate is obtained as soluble COD. The present invention is a simulation method for biodegradation of soluble COD that is closely related to biodegradation. Since solid COD is hardly biodegraded and is finally removed by sedimentation separation, it is excluded from the present invention.

  Soluble COD is divided into biodegradable COD and persistent biodegradable COD with little biodegradability. As will be described later, for example, treated water treated with an aerobic biological aerobic treatment in a biological reaction tank, or treated water after a batch test in which the aqueous water reacts with microorganisms in the biological reaction tank. It is obtained by analyzing the later soluble COD concentration and the known component concentration, and subtracting the treated water known component COD concentration from the treated water soluble COD concentration. The hardly decomposable COD concentration has little fluctuation and low concentration in the inflowing water. Therefore, it is possible to predict the soluble COD without any problems even if there are some fluctuations.

  Furthermore, biodegradable COD is divided into known components COD of phenol, thiosulfuric acid and thiocyan, and other unknown components COD which are other biodegradable CODs. In general, in aquatic water, known components such as phenol, thiosulfuric acid and thiocyan account for about 60 to 80% of biodegradable COD, and unknown component COD accounts for about 20 to 40% of the total. Therefore, a certain degree of accuracy can be obtained even in the simulation of the known component, but the accuracy can be further improved by combining with the simulation of the unknown component. The unknown component COD in the water is easily biodegradable, and the composition of the unknown component hardly changes from factory to factory. Therefore, it is possible to put the unknown component COD together and grasp its behavior. Furthermore, it is also possible to calculate by including phenol that is easily biodegraded among the known components in the unknown component COD.

  FIG. 2 is a diagram exemplifying a flow of the method for simulating the COD concentration of safe water according to the present invention. In addition, each “process” in the figure can be replaced with each “means”, and is also a diagram illustrating a simulation apparatus for water safety.

  Further, the treated water in FIG. 2 refers to treated water after biological aerobic treatment in the case of continuous treatment, and in-tank water after a predetermined time in the case of batch treatment.

  In addition, biological aerobic treatment means that a substrate and microorganisms exist, and in a reaction vessel having an aeration apparatus, mixing and stirring are performed while supplying dissolved oxygen by aeration, and the substrate and microorganisms are removed. A method of decomposing a substrate by contacting and reacting.

  As shown in FIG. 2, the COD concentration simulation method 1 according to the present invention includes an analysis step 2 for analyzing the aquatic water flowing into the biological aerobic treatment process, and known inflowing phenol, thiosulfuric acid, and thiocyanate. A known component COD conversion fractionation step 4 for converting to a known component COD concentration 5 using the correlation 3 between the component concentration and the COD concentration, and treated water in which the aquatic water is subjected to biological aerobic treatment in a biological reaction tank Or, analyze the soluble COD concentration and the known component concentration remaining in the treated water, and subtract the known component COD concentration from the soluble COD concentration in the treated water after the batch test in which the aqueous water and the microorganisms in the biological reaction tank are reacted. Refractory COD concentration step 7 to determine the hard-to-decompose COD concentration 6, and the known component COD concentration 5 and difficult from the soluble COD concentration 8 of the inflowing water obtained in the analysis step 2 An unknown component COD fractionation step 10 for determining the unknown component COD concentration 9 of the inflowing water by subtracting the desolvable COD concentration 6 and the stoichiometric parameters (growth yield) and reaction rate parameters (saturation constant and maximum) Specific growth rate), and parameter setting step 11 for setting parameters of the type and concentration of microorganisms that decompose phenol, thiosulfuric acid, thiocyanate and unknown component COD, and a dissolved oxygen concentration measuring step for measuring the dissolved oxygen concentration in the biological reaction tank 12. Using the parameters and dissolved oxygen concentration, the known component COD concentration 5 of the inflowing safe water and the unknown component COD concentration 9 of the inflowing safe water, biological water is Simulation of predicted known component COD concentration 13 and treated unknown predicted component COD concentration 14 of aerobic treated water The predicted COD concentration 17 of the treated water is calculated by adding the hardly decomposable COD concentration 6 to the calculated calculation process 15 and the predicted known component COD concentration 13 and predicted unknown component COD concentration 14 of the calculated treated water. A treated water predicted COD concentration calculation step 16 is provided.

  As will be described later, in the above parameter setting, it is desirable to have time-series data of soluble COD concentration, phenol concentration, thiosulfuric acid concentration, thiocyanate concentration, unknown component COD concentration, persistent COD concentration, and dissolved oxygen concentration in advance. . On the other hand, the phenol concentration, thiosulfuric acid concentration, thiocyan concentration, unknown component COD concentration, persistent COD concentration, and dissolved oxygen concentration used for the simulation need not be time-series data, and may be data of a required time section. For example, when a simulation is performed up to 10 days after the present time, it is assumed that the current phenol concentration, thiosulfate concentration, thiocyan concentration, unknown component COD concentration, and persistent COD concentration are assumed to be constant for 10 days. Is also possible.

  In addition, it is desirable that the time section to be obtained uses data before that time in consideration of the residence time of the biological reaction tank. For example, when determining the phenol concentration, thiosulfuric acid concentration, thiocyan concentration, unknown component COD concentration and persistent COD concentration in the current treated water, if the biological reaction tank has a residence time of 10 hours, it will flow in 10 hours before. It is desirable to use low water data.

In the analysis step 2, the method of analyzing the known component concentrations of the inflowing aqueduct COD, phenol, thiosulfuric acid, and thiocyanate is not specified, but it is desirable to use the same analysis method every time. For example, for COD concentration, oxygen consumption (COD _Mn ) by potassium permanganate in JIS K0102 100 ° C. permanganate, or oxygen consumption (COD _Cr ) by potassium dichromate, and JIS K0102 absorbance for phenol concentration Methods, thiosulfuric acid, and thiocyanate concentrations can be analyzed by ion chromatography analysis, and MLSS concentrations can be analyzed by Non-Patent Document 1 described above. For each analysis method, it is desirable to consistently use the same method in the present invention in order to prevent an error in the analysis value due to a difference in the analysis method.

Correlation 3 is obtained from the known component concentration and the COD concentration. As an example, FIG. 3 shows a correlation based on measured values of phenol concentration, thiosulfuric acid, thiocyan and COD _Mn concentration. As a result, the oxygen consumption per 1 mg of phenol, thiosulfuric acid, and thiocyan was 2.1 mg, 0.48 mg, and 1.0 mg, respectively. Further, when determining the correlation, it is desirable to use any of the analytical methods of the same COD _Cr or COD _Mn and method of measuring the COD concentration in the analysis step, analysis method using the same method consistently.

Thus, the known component concentrations, when determining the correlation between the COD concentration without using a COD _Cr, it is possible to use the analysis results of the COD _Mn, dangerous and harmful as COD _Cr There is an advantage that it is not necessary to perform analysis using certain chemicals.

In addition, as a method for easily obtaining the correlation between the concentration of each component and the COD concentration, there is a method of calculating the theoretical oxygen consumption of the component from the chemical reaction equation. For example, the theoretical oxygen consumption per mg of phenol, thiosulfuric acid and thiocyan is the following chemical reaction formulas (1) to (3);
C ₆ H ₅ OH + 7O ₂ → 6CO ₂ + 3H ₂ O (1)
S ₂ O ₃ ²⁻ + 2O ₂ + H ₂ O → 2SO ₄ ²⁻ + 2H ⁺ (2)
SCN ⁻ + 2O ₂ + 2H ₂ O → SO ₄ ²⁻ + NH ₄ ⁺ + CO ₂ (3)
Are calculated as 2.38 mg, 0.57 mg, and 1.1 mg, respectively.

Here, the reason why the oxygen consumption in FIG. 3 is different from the theoretical oxygen consumption is that the analysis by COD _Mn does not have an oxidative power that can be theoretically completely oxidized, and is estimated to be low.

  In the known component COD conversion fractionation step 4, the known component concentration obtained in the analysis step 2 is converted into the known component COD concentration 5 using the correlation 3.

  In addition, sulfur compounds such as thiosulfuric acid and thiocyan can be simulated in terms of sulfur here. Thus, by separately considering thiosulfuric acid and thiocyan as sulfur components, it is possible to calculate sulfate ion components that are not counted as COD. Thereby, it becomes possible to trace the mass balance of sulfur, and the behavior of the sulfur component can be grasped. However, even if the sulfur material balance is obtained by converting to sulfur, the oxygen material balance is obtained, so that the simulation is not affected. In addition, microorganisms that decompose sulfur compounds are generally considered to be sulfur-oxidizing bacteria, and unlike heterotrophic bacteria that decompose organic matter, they are considered not to interact with each other. Therefore, the accuracy increases by considering the sulfur compound separately from the other components. In that case, the sulfur conversion values of 1 mg of thiosulfuric acid and thiocyan are calculated as 0.57 mg and 0.55 mg from the chemical reaction formulas (1) to (3), respectively.

  In the hardly decomposable COD fractionation step 7, in the treated water that has been subjected to biological aerobic treatment in the biological reaction tank, or in the treated water after the batch test in which the aqueous water and microorganisms in the biological reaction tank are reacted. The soluble COD concentration after treatment and the known component concentration are analyzed, and the hardly decomposable COD concentration 6 is determined by subtracting the known component COD concentration of the treated water from the treated water soluble COD concentration. The purpose here is to quantify persistent COD that is not decomposed by biological treatment for a predetermined time, that is, does not change before and after the simulation. In the above-described biological aerobic treatment and batch test, it is desirable to perform the treatment until the soluble COD hardly decreases with time. The criterion for not decreasing is related to the accuracy of the simulation. For example, when the accuracy of the simulation prediction is set within ± 5%, even in the batch test, even if the residence time of the biological reaction tank targeted by the simulation elapses A state where the decrease in the soluble COD concentration in the batch test is within 5% of the original soluble COD concentration is conceivable. When the accuracy of simulation prediction is not determined in advance, for example, it is determined that the state does not decrease by performing a 5-day decomposition process using a JIS K0102 biochemical oxygen consumption (BOD) analysis method. be able to. In addition, a biological aerobic treatment usually employs a treatment time in which biodegradable COD is sufficiently decomposed, but in some cases, the decomposition time may be insufficient. However, if it is difficult to obtain data, it is desirable to confirm it by a batch test.

  In the unknown component COD fractionation step 10, the inflow by adding the known component COD concentration 5 and the hardly decomposable COD concentration 6 of the inflowing aqueous water from the inflowing water-soluble soluble COD concentration 8 obtained in the analysis step 2. Determine the unknown component COD concentration of 9 in water. An unknown component is a COD component other than phenol, thiosulfuric acid, and thiocyan in an aqueous solution, and indicates an organic or inorganic substance having biodegradability.

  Further, when determining the unknown component COD concentration, there is a possibility that the sum of the known component COD concentration 5 and the hardly decomposable COD concentration 6 of the inflowing water exceeds the soluble COD concentration due to errors in the analysis method. In this case, the unknown component COD concentration may be considered to be negligibly low, and the unknown component COD concentration may be calculated as zero.

  Moreover, you may simulate simply by including the phenol which is a known component in an unknown component. As a result, it is not necessary to analyze the phenol concentration, and a simulation can be performed by analyzing only the solubility COD concentration 8 of hydrated water flowing in analysis step 2, thiosulfuric acid, and thiocyanate concentration. However, since parameters in the unknown component decomposition may be affected by fluctuations in the phenol concentration, it is necessary to carefully set parameters in the simulation, such as increasing the frequency of calibration described later.

  Further, the unknown component may be divided into a plurality of components from the time-series change of the unknown component COD concentration, and a simulation may be performed. For example, when the unknown component COD concentration decomposition rate in the initial stage of the reaction in the time series change of the unknown component COD concentration in a batch test or the like is greatly different from the subsequent decomposition rate, the unknown component COD concentration is divided into two components. The simulation is performed as an unknown component a and an unknown component b.

  In the parameter setting step 11, the type and concentration of microorganisms that decompose phenol, thiosulfuric acid, thiocyan and unknown component COD, and the growth yield and reaction for the stoichiometric parameters phenol, thiosulfuric acid, thiocyan and unknown component COD. Saturation constants and maximum specific growth rates for the phenol, thiosulfuric acid, thiocyan and unknown component COD, which are kinetic parameters, are set. The setting method can be broadly divided into (A) a method in which an experiment is performed and experimental data under a certain condition is analyzed, and (B) a method in which document values are picked up. The former method in which parameter setting is performed is preferable.

  The method (A) will be described below. This method is based on (a) inflowing aqueous and treated water, using samples collected separately in time series prior to the simulation, using soluble COD concentration, phenol concentration, thiosulfuric acid. Analyzing and measuring the concentration, thiocyanate concentration, persistent COD concentration, unknown component COD concentration, and dissolved oxygen concentration in the biological reaction tank, respectively, and using the calculation formula (2) described later, the parameters in the simulation are , A method of determining by calibration, (a) using a batch test device that continuously measures dissolved oxygen concentration using a dissolved oxygen meter, microorganisms in a biological reaction tank, and inflowing or falling water In the oxygen consumption rate test in which the components of the above are reacted in a batch container, oxygen consumption rate data, and soluble COD concentration, phenol concentration, A method for determining the parameters in the simulation by collecting time series data of the concentration of osulfate, thiocyanate, persistent COD, and unknown component COD, and using arithmetic expressions (3) to (6) described later. Set the parameters in advance using either method (a) or (b). However, the above-mentioned hardly decomposable COD concentration may be determined in advance from the hardly decomposable COD fractionation step 7, but (a) the soluble COD concentration in treated water or (b) at the end of the batch test. The soluble COD concentration may also be determined by this to perform the same operation. The unknown component is determined by the unknown component COD fractionation step 10.

  For the time series measured value data of (a) above, a specific data acquisition method is not specified, but time series data is collected so that the density change can be understood. For example, if the quality of treated water for one week is simulated, it is desirable to acquire data at the time when three or more points in between, for example, 2, 4, and 6 days have passed. In addition, it is desirable that the time-series measured value data is stable. For example, in the case described above, data in which the concentration and composition of the inflowing water-containing components greatly fluctuate during one week is not desirable. For example, when the accuracy of the simulation prediction is set within ± 5%, the fluctuation range of the concentration of components of the cold water flowing in at the time interval of the simulation biological treatment time (residence time) is 5%. Can be used.

  The method of determining by the calibration in (a) is not particularly specified. For example, the commercially available ASM simulation software AQUASIM is used to calculate the time series measured value, the calculated value, and the standard deviation of the time series measured value from the following equation (2 ):

{Where χ ² (p) is the value of χ ² of the target model parameter p, and y _{meas, m} is the actual measurement value (component concentration or oxygen consumption rate) of the m-th time series data , Y _m (p) is the calculated value (component concentration or oxygen consumption rate) of the m th time series data assuming the value of the model parameter p, and σ _{meas, m} is the m th time series The standard deviation of the measured value of the data or the standard deviation of the entire measured value, and n is the number of data points. }
Obtains the value of the chi ² by, there is a method of using a value of the parameter when the value of the chi ² is minimized. The method for obtaining the parameter value is not specified, but a numerical analysis method such as a simplex method, a Monte Carlo method, or a genetic algorithm is preferable.

  The method for determining parameters from the oxygen consumption rate data in the oxygen consumption rate test (a) above uses the test apparatus of FIG. In FIG. 4, the microbial sludge 22 used in the biological treatment process and the nitrification inhibitor 23 are added to the oxygen consumption rate test apparatus 21 in order to suppress oxygen consumption when ammoniacal nitrogen is nitrified to nitrate nitrogen. The liquid of the oxygen consumption rate test apparatus 21 is mixed by the apparatus 24. Nutrient salt 25 may be added to prevent a decrease in the activity of microorganisms due to lack of nutrient salt. Next, the target component 26 is added to the oxygen consumption rate test apparatus 21, and the change over time in the dissolved oxygen concentration is measured by the dissolved oxygen concentration meter 27. Recording of the dissolved oxygen concentration may be performed by the data recording device 28. In order to control the dissolved oxygen concentration to a certain level or higher during the measurement, air may be supplied by the air supply device 29 when it falls below the control value. In order to control the pH to be constant, the pH may be measured by the pH meter 30, and the acid or alkali may be supplied by the acid / alkali supply device 31 for control. In order to control the temperature of the oxygen consumption rate test apparatus 21, a constant temperature water tank 33 provided with a heater 32 may be used.

  The method for determining parameters from the change over time in dissolved oxygen concentration and oxygen consumption rate obtained by adding the target component (hereinafter referred to as component A) is not particularly limited. From the COD equivalent concentration of A and the oxygen consumption, the following equation (3):

{ _Where Y _A is the growth yield of microorganisms that degrade component A, S _{A, COD} is the COD equivalent concentration of component A, and O _2meas is the actual measured value of oxygen consumption. }
Can be obtained.

  The method of obtaining the growth yield more precisely is to obtain the oxygen consumption rate by endogenous breathing in advance and subtract the oxygen consumption rate by endogenous breathing from the measured value of the above oxygen consumption to obtain the oxygen used for growth. The consumption speed can be obtained.

  The method for determining the value of the maximum specific growth rate and the saturation constant is not particularly limited. For example, it can be obtained using the method described in Non-Patent Document 2 described above. In other words, this method is a method in which the microbial sludge used in the oxygen consumption rate test is aerated for 1 hour, and then the microbial sludge is mixed with low water at various dilution rates to measure the oxygen consumption rate. During measurement, control with aeration is performed to keep the dissolved oxygen concentration constant. Next, the specific oxygen consumption rate is obtained by dividing the measured oxygen consumption rate by the sludge concentration, and the specific oxygen consumption rate minus the oxygen consumption rate by endogenous respiration (specific substrate oxidation rate) is obtained. The specific endogenous respiration rate is the oxygen consumption rate due to endogenous respiration when component A is not added, and is obtained from the oxygen consumption rate when component A is not added in the oxygen consumption rate test. Desired. At this time, between the specific growth rate and the specific substrate oxidation rate, the following equation (4):

{Wherein μ _A is the specific growth rate of the microorganism that degrades component A and r _ox is the specific substrate oxidation rate. }
The relationship shown in is established.

On the other hand, between the specific growth rate mu _A and the maximum specific growth rate mu _{A, max,} the following arithmetic expression (5):

{Wherein, mu _{A, max} is the maximum specific growth rate of the microorganisms decompose the component A, K _A is the saturation constant for COD conversion value of component A concentration, S _{A, COD} is the component A It is the COD equivalent concentration, S _O2 is the dissolved oxygen concentration, and K _O2 is the saturation constant for the dissolved oxygen concentration. }
The Michaelis-Menten equation is established.

Here, in the oxygen consumption rate test, since the dissolved oxygen concentration is maintained at a high concentration, the value of S _O2 / (K _O2 + S _O2 ) can be regarded as approximately 1. Therefore, the specific growth rate can be regarded as a function of only the component concentration. From the above, a plot of the value of specific growth rate μ _A obtained by the calculation formula (4) and the component concentration is obtained, and by fitting the formula of the calculation formula (5) to the plot, the specific maximum growth of microorganisms The rate and saturation constant for component A are determined.

  The method for determining the type and concentration of microorganisms that decompose phenol, thiosulfuric acid, thiocyanate, and unknown components is not particularly limited, but basically one type of microorganism corresponds to the decomposition for one component. It is desirable. In addition, since one type of microorganism may decompose multiple components based on experimental data and literature, a single component of multiple components can be used to improve calculation prediction and calculation prediction accuracy based on actual phenomena. May be set to correspond. However, multiple types of microorganisms may decompose one component, but they often exhibit the same degradation action, and the amount of calculation increases by increasing the number of microorganisms. It is desirable to correspond to one type of microorganism. In the present invention, the heterotrophic bacteria cope with the degradation of phenol and unknown components. However, if there are components of unknown components that can be easily identified and quantified, a corresponding type of microorganism is set. Also good. Regarding the concentration of the microorganism, the oxygen consumption rate using the organic component and the inorganic component of the compound component is expressed by the following equation (6):

{Where OUR is the rate of oxygen consumption, and X _A is the COD value of the concentration of the microorganism that degrades component A, and Y _A , S _A , K _O2 , and S _O2 are arithmetic expressions ( 3) to (5). }
There is a method using this formula.

That is, in Equation (6), the maximum specific growth rate and the saturation constant for component A are determined by the above-described method. In the oxygen consumption rate test, the dissolved oxygen concentration is maintained at a high concentration, so that S _O2 / (K _O2 The value of + S _O2 ) can be regarded as almost 1. From this, the oxygen consumption rate is expressed only as a function of the concentration of microorganisms that decompose component A. Therefore, X _A can be determined by fitting the OUR calculated value obtained by substituting the component A concentration analysis value into the arithmetic expression (6) and the OUR actual measurement value obtained in the oxygen consumption rate test.

  With respect to the method of picking up the literature value of (B) above, for example, typical parameter values are described in Non-Patent Literature 3 described above, and the yield of heterotrophic organisms under aerobic conditions is 0.63. Has been. Although this value may be set as a parameter value, the value may be different depending on the water-resistance condition of interest, and therefore it is desirable to set it by the method (A) as much as possible. In addition, it is desirable to reset the parameter value due to differences in the concentration and composition of the aqueous solution when the desired simulation accuracy cannot be obtained. For example, when the accuracy of simulation prediction is set within 5%, resetting is performed when the error between the actual value and the simulation value becomes 5% or more.

  The dissolved oxygen concentration 12 is a method of using a value obtained by measuring a dissolved oxygen concentration in a biological reaction tank by installing a dissolved oxygen concentration meter in a biological treatment process, or treating the dissolved oxygen concentration as a parameter in the parameter setting step 11; Any method using values determined by calibration may be used. However, in the method using the value obtained by measuring the dissolved oxygen concentration in the biological reaction tank, it is desirable to collect time series data and use it as an input value for simulation. If it is difficult to collect time-series data, use the dissolved oxygen concentration in the time cross section to calculate. For example, when a simulation is performed up to 10 days after the present time, it is input assuming that the current dissolved oxygen concentration is constant for 10 days.

  The calculation step 15 uses the parameters of the known component COD concentration 5 of the inflowing water and the unknown component COD concentration 9 of the inflowing water, the dissolved oxygen concentration, and the predicted known component COD concentration 13 of the treated water, The predicted unknown component COD concentration 14 is obtained. For the calculation, the above-described arithmetic expression (1) based on the IWA activated sludge model is used. However, since the hardly degradable COD concentration is a non-biodegradable COD, it is not included in the calculation process. In the simulation, the COD concentration in the reaction time in the biological reaction tank is obtained, and therefore the COD concentration after a certain residence time coincides with the treated water COD concentration.

Further, in the calculation step 15, a simulation including the influence of pH, alkalinity, ammonia concentration and the like may be performed. Although the calculation method is not specified, for example, hydrogen ion concentration, dissolved carbon dioxide concentration, ammonia concentration, etc. are added to C _i, and stoichiometric parameters such as hydrogen ion concentration, dissolved carbon dioxide concentration, ammonia concentration, etc. are added to P _ij , And the reaction rate equation may be added to ρ _j for the calculation. In addition, in order to improve the prediction accuracy by taking into account the effects of organisms' self-degradation in biological treatment, the ratio of conversion to floating inert organic substances in the stoichiometric parameters and the reaction rate parameters under aerobic conditions. Although the specific endogenous respiratory rate of the organism may be set, it is not necessary to set it because the influence is usually small.

  In addition, the flow rate and concentration can be considered for fluctuations in the inflowing water. In order to simulate these fluctuations, it is possible to obtain the concentration of the treated water by calculating, for example, using the arithmetic expression (7) based on the flow rate and concentration data over time.

Where C _{i is the} concentration of each known component COD and the unknown component COD i is a serial number representing the type of each known component COD and unknown component COD P _ij is a stoichiometric parameter j is a serial number representing each process ρ _{j is a} reaction rate equation (Rate equation including reaction rate equation parameters)
Q: Aqueous water amount in: Notation representing inflowing aqueous out out: Notation representing outflowing aqueduct V: Volume of biological reaction tank

  According to this arithmetic expression, COD concentration change due to inflow and outflow in the biological reaction tank can be obtained by inputting time-lapse data of the flow rate and concentration of continuously changing water.

  In the treated water COD concentration calculation step 16, the estimated known component COD concentration 13 of treated water, the predicted unknown component COD concentration 14 of treated water, and the persistent COD concentration 6 are summed up to calculate the predicted COD concentration of treated water. 17 is calculated.

Example 1: Simulation of a batch test for real water (Phenol is treated as a known component)
Hereinafter, the simulation method of the batch test for safety water will be described, particularly when phenol is handled as a known component. In the batch test, artificial seawater, actual water and activated sludge were added to a 1 L reaction vessel, and the MLSS concentration was about 500 mg / L for 24 hours. About this test time, after examining by the batch test beforehand and confirming the time when a change is not seen in soluble COD, time sufficient for processing was set. In the measurement, the dissolved oxygen concentration was measured with a dissolved oxygen concentration meter, and the pH was measured with a pH meter. The dissolved oxygen concentration was controlled to 3.25 mg / L and the pH to 7.5.

  The analysis step 2 is a step of analyzing the soluble COD concentration and the known component concentration in the wastewater flowing into the biological treatment process. Here, the initial components of phenol, thiosulfuric acid, and thiocyan in the batch test apparatus described above are analyzed. The phenol concentration was confirmed by JIS K0102 absorptiometry, the thiosulfate and thiocyan concentrations were confirmed by ion chromatography analysis, and the MLSS concentration was confirmed by the centrifugation method described in Non-Patent Document 1.

Based on the obtained analysis data, in the known component COD conversion step 4 of the inflowing water, the known component COD concentration of the inflowing water based on the relational expression of phenol, thiosulfuric acid, thiocyan and COD _Mn. 5 was determined. In the hardly decomposable COD fractionation step 7, the hardly decomposable COD concentration 6 was determined by subtracting the treated water known component COD concentration from the treated water soluble COD concentration after 24 hours of the batch test. In the unknown component COD fractionation step 10, the unknown component COD concentration 9 of the inflowing water is changed to the known component COD concentration 5 and the hardly decomposable COD concentration 6 of the inflowing aqueous solution from the soluble COD concentration 8 of the inflowing water. Determined by subtracting.

In the parameter setting step 11, the growth yield, the maximum specific growth rate, the saturation constant, and the heterotrophic bacterium concentration, thiosulfate-decomposing bacterium concentration, and thiocyanate-decomposing bacterium concentration used in the calculation step 15 described later were set. As a setting method, a method based on calibration was performed as a method of determining from the oxygen consumption rate data of the oxygen consumption rate test. A commercially available ASM simulation software AQUASIM was used for calibration. Specifically, the value of χ ² shown in the calculation formula (2) is obtained from the measured value, the calculated value, and the standard deviation of the measured value, and the parameter value when the value of χ ² is minimized is calculated. . With respect to the actual measurement values, changes over time in phenol concentration, thiosulfate concentration, and thiocyan concentration were obtained from batch tests for each component performed in advance. The insoluble decomposable COD concentration and unknown component COD concentration of the inflowing water were determined from the batch test results of this example. The calculated value was obtained by the method of calculation step 15 described later. As the dissolved oxygen concentration, a control value of 3.25 mg / L in the batch test was used.

The calculation step 15 uses the known component COD concentration 5 of the inflowing water, the dissolved oxygen concentration, and the parameters to change the phenol component, the thiosulfuric acid, the known component COD concentration of the thiocyanate concentration, and the unknown component COD concentration with time. The calculation accuracy of the soluble COD concentration of the treated water was confirmed. As the calculation method, the arithmetic expression (1) was used. Table 1 shows each component concentration C _i used in the calculation, the stoichiometric parameter, and the reaction rate parameter. Table 2 shows the stoichiometric relationship in process ρ _j , for example, in the growth of heterotrophic bacteria in process ρ ₁ , P ₁₁ = −1 / Y _Phe versus heterotrophic bacteria (X _H ). This indicates that the phenol concentration increases in proportion and S _O2 increases in the proportion of P ₄₁ = 1−1 / Y _Phe . Table 3 shows the reaction rate equation used for the calculation. For example, in the growth of phenol-degrading bacteria in process ρ _1, the rate of increase in phenol concentration is expressed as in equation (8).

{ _Wherein S _Phe is the phenol concentration, t is the time, S _O2 is the dissolved oxygen concentration, K _O2 is the saturation constant for the dissolved oxygen concentration, and K _Phe is the phenol concentration. Saturation constant, X _Phe is the concentration of phenol-degrading bacteria, and μ _Phe and Y _Phe are those defined in Tables 1-3. }
It is represented by

  Moreover, about thiosulfuric acid and thiocyan, it calculated by the sulfur equivalent. In addition, it is conceivable that one kind of sulfur-oxidizing bacterium can degrade these two components, but here, microorganisms that decompose each component are set for thiosulfate and thiocyan.

  The result of the simulation is shown in FIG. FIG. 5 shows the change over time in the soluble COD concentration and the simulation results of this example. As described above, according to the present example, in the biological aerobic treatment of the aqueous water, the known component COD concentration 5 of phenol, thiosulfuric acid, and thiocyan, the persistent COD concentration 6 and the unknown component By fractionating to a COD concentration of 9 and applying an activated sludge model, the COD concentration of the treated water can be predicted.

Example 2: Simulation of a batch test for actual low water (Phenol is treated as an unknown component)
Hereinafter, a simulation method when setting phenol as an unknown component in Example 1 will be described. The batch test was performed under the same conditions as in Example 1. However, the phenol concentration was not measured in the analysis step 2. In the known component COD conversion step 4 of the inflowing aqueous water, the known component COD concentration 5 of the inflowing aquatic water was determined based on the relational expression of thiosulfuric acid, thiocyan and COD _Mn , excluding the phenol. The hardly decomposable COD fractionation step 6 was performed in the same manner as in Example 1. In the unknown component COD fractionation step 10 of the inflowing water, the unknown component COD concentration 9 of the inflowing water is changed from the soluble COD concentration 8 of the inflowing water into the known component COD concentration 5 (phenol Excluding) and subtractable COD concentration 6 was subtracted.
However, from the batch test results, it was considered that the decomposition rate of the unknown component COD concentration at the beginning of the reaction was different from the decomposition rate thereafter, so the unknown component COD concentration was fractionated into unknown component a and unknown component b, and parameter settings were made. And a simulation was performed. Details will be described later in calculation step 15.

The parameter setting step 11 was performed in the same manner as in Example 1.
The calculation step 15 uses the known component COD concentration 5 and dissolved oxygen concentration and parameters of the inflowing water to calculate the thiosulfuric acid excluding the phenol in the batch test, the known component COD concentration of the thiocyanate concentration, and the unknown component COD concentration. A time-dependent change simulation was performed to confirm the calculation accuracy of the treated water-soluble COD concentration. As the calculation method, the arithmetic expression (1) was used. Table 4 shows each component concentration C _i used in the calculation, the stoichiometric parameter, and the reaction rate parameter. Table 5 shows the stoichiometric relationship in the process ρ _j . Table 6 shows the reaction rate equation used for the calculation.

  Here, the decomposition of the unknown component results as shown in FIG. 6, and the decomposition rate is greatly reduced after 60 minutes. Therefore, the unknown component is fractionated into the unknown component a and the unknown component b. A speed equation was set. Since phenol and unknown component a and unknown component b are considered to be degraded by heterotrophic bacteria, the same stoichiometric relationship and reaction rate equation were set. However, since the parameter values in these components are different, they do not have the same decomposition rate equation.

  Moreover, about thiosulfuric acid and thiocyan, it calculated by the sulfur equivalent similarly to Example 1.

  The result of the simulation is shown in FIG. FIG. 7 shows the change over time in the soluble COD concentration and the simulation results of this example. As described above, according to the present example, in the biological aerobic treatment of the aqueous water, by including phenol as an unknown component, the known component COD concentration of thiosulfuric acid and thiocyan, the persistent COD concentration, The COD concentration of treated water can be predicted by fractionating into an unknown component COD concentration (two components) containing phenol and applying an activated sludge model. This makes it possible to easily simulate the treated water-soluble COD concentration without analyzing the phenol concentration in the analysis step 2. However, since parameters in unknown component decomposition may be affected by fluctuations in phenol concentration, it is necessary to carefully set parameters such as increasing the frequency of calibration in the simulation.

Example 3 Simulation from Continuous Test Data for Actual Aqueous Water A method for treating phenol as an unknown component and performing a treated water COD simulation from continuous test data as in Example 2 will be described below. In the continuous test, two 200L reaction tanks, one 100L reaction tank and one settling tank are connected to actual low water from the previous stage, and run for about 12 hours. Processed. In the analysis step 2, as in Example 2, the phenol concentration was not measured. In the known component COD conversion step 4 of the inflowing safe water, the same component COD concentration 5 of the inflowing safe water was determined as in Example 2, except for the phenol. The hardly degradable COD fractionation step 7 was determined by subtracting the COD concentration of the known component from the soluble COD concentration based on the treated water data when the biodegradable COD was stably treated. In the unknown component COD fractionation step 10, the unknown component COD concentration 9 of the inflowing water was determined in the same manner as in Example 2. About the unknown component COD density | concentration, it fractionated into the unknown component a and the unknown component b similarly to Example 2, and parameter setting was implemented.

  In the parameter setting step 11, the growth yield, the maximum specific growth rate, the saturation constant, and the heterotrophic bacterium concentration, thiosulfate-decomposing bacterium concentration, and thiocyanate-decomposing bacterium concentration used in the calculation step 15 described later were set. The setting method is the analysis of the dissolved COD concentration, thiosulfuric acid, and thiocyanate concentration in 4 points (0 days, 3 days, 15 days, and 17 days later) inflowing water and treated water obtained in this example. The value and the data of the hardly-decomposable COD concentration and the unknown component COD concentration calculated from the analysis value were substituted into the equation (2) and determined by calibration. A commercially available ASM simulation software AQUASIM was used for calibration. The calculated value was obtained by the method of calculation step 15 described later. As the dissolved oxygen concentration, a control value of 2.0 mg / L of the continuous test was used.

Calculation step 15 uses the above parameters to simulate thiosulfuric acid, thiocyanate concentration and unknown component COD concentration in the treated water for 45 days after the continuous test of this example, and add to the persistent COD concentration of 6. By combining them, a simulation of the treated water COD concentration 17 was performed. The calculation method was performed by substituting the known component COD concentration and the unknown component COD concentration of the inflowing water into the calculation formula (1) after 45 days. Table 4 shows each component concentration C _i used in the calculation, the stoichiometric parameter, and the reaction rate parameter. Table 5 shows the stoichiometric relationship in the process ρ _j . Table 6 shows the reaction rate equation used for the calculation. Moreover, the calculation accuracy was confirmed by comparing the calculation result with the actual measurement value.

  Moreover, about thiosulfuric acid and thiocyan, it calculated by the sulfur equivalent similarly to Examples 1 and 2.

  The result of the above simulation is shown in FIG. FIG. 8 shows the dissolved COD measured value, treated water-soluble COD measured value, and treated water-soluble COD concentration simulation result that flowed in after 45 days of the continuous test of this example. As described above, according to this example, in the biological aerobic continuous treatment process of water, phenol is included as an unknown component, parameters are set by calibration from continuous test data, and the parameter values are based on the parameters. Even when different water flows into the water, it is fractionated into the known component COD concentration of thiosulfuric acid and thiocyan, 5 and the difficult-to-decompose COD concentration and the unknown component COD concentration (2 components) containing phenol, and activated sludge. By applying the model, the COD concentration of the treated water can be predicted. Thus, COD simulation of continuous treatment is possible, and the treatment water-soluble COD concentration can be easily simulated without analyzing the phenol concentration in the analysis step 2. However, as in Example 2, the parameters in the unknown component decomposition may be affected by fluctuations in the phenol concentration. Therefore, it is necessary to carefully set parameters such as increasing the frequency of calibration in the simulation. is there.

Example 4: Simulation in consideration of flow rate variation of actual safe water Hereinafter, a method for conducting a treated water COD simulation from continuous test data in which phenol is treated as an unknown component and the inflowing water amount is varied as in Example 3 will be described. To do. FIG. 9 is a diagram exemplifying a flow of the safe water COD concentration simulation method in consideration of the flow rate variation of actual safe water in the present embodiment. The continuous test was performed in the same reaction tank, sedimentation tank, residence time, and test period as in Example 3. However, the inflow low water amount was changed to 3.0 times after 30 days on the basis of the water amount on the 0th day. In the analysis step 2, as in Example 3, the phenol concentration was not measured. In the known component COD conversion step 4 of the inflowing safe water, the same component COD concentration 5 of the inflowing safe water was determined as in Example 3, except for the phenol. The hardly degradable COD fractionation step 7 was determined by subtracting the COD concentration of the known component from the soluble COD concentration based on the treated water data when the biodegradable COD was stably treated. In the unknown component COD fractionation step 10, the unknown component COD concentration 9 of the inflowing water was determined in the same manner as in Example 3. About the unknown component COD density | concentration, it fractionated into the unknown component a and the unknown component b similarly to Example 3, and parameter setting was implemented.

  In the parameter setting step 11, the growth yield, the maximum specific growth rate, the saturation constant, and the heterotrophic bacterium concentration, thiosulfate-decomposing bacterium concentration, and thiocyanate-decomposing bacterium concentration used in the calculation step 15 described later were set. The setting method is the analysis of the dissolved COD concentration, thiosulfuric acid, and thiocyanate concentration in 4 points (0 days, 3 days, 15 days, and 17 days later) inflowing water and treated water obtained in this example. The value and the data of the hardly-decomposable COD concentration and the unknown component COD concentration calculated from the analysis value were substituted into the equation (2) and determined by calibration. A commercially available ASM simulation software AQUASIM was used for calibration. The calculated value was obtained by the method of calculation step 15 described later. As the dissolved oxygen concentration, a control value of 2.0 mg / L of the continuous test was used.

Calculation step 15 uses the above parameters to simulate thiosulfuric acid, thiocyanate concentration and unknown component COD concentration in the treated water for 45 days after the continuous test of this example, and add to the persistent COD concentration of 6. By combining them, a simulation of a treated water COD concentration of 17 was performed. The calculation method was performed by substituting the known component COD concentration and the unknown component COD concentration of the inflowing inflow water after 45 days into the arithmetic expression (8) by using the amount of the aqueous solution and the volume of the reaction tank. Table 4 shows each component concentration C _i used in the calculation, the stoichiometric parameter, and the reaction rate parameter. Table 5 shows the stoichiometric relationship in process ρ _j . Table 6 shows the reaction rate equation used for the calculation. Moreover, the calculation accuracy was confirmed by comparing the calculation result with the actual measurement value.

  Moreover, about thiosulfuric acid and thiocyan, it calculated by the sulfur equivalent similarly to Examples 1-3.

  The result of the simulation is shown in FIG. FIG. 10 shows the dissolved COD measured values, treated water soluble COD measured values, and treated water soluble COD concentration simulation results that flowed in after 45 days of the continuous test of this example. As described above, according to this example, in the biological aerobic continuous treatment process of water, phenol is included as an unknown component, parameters are set by calibration from continuous test data, and the parameter values are based on the parameters. Even when different aqueous water flows into the water and the inflow amount of the aquatic water fluctuates, the known component COD concentration of thiosulfuric acid, thiocyan, 5 and the unknown component COD concentration including phenol (two components) ) And applying the activated sludge model, the COD concentration of the treated water can be predicted. This makes it possible to perform COD simulation when the inflow amount of continuous treatment is changed, and to easily simulate the treated water-soluble COD concentration without analyzing the phenol concentration in the analysis step 2. However, as in Example 3, parameters in the unknown component decomposition may be affected by fluctuations in the phenol concentration. Therefore, in the simulation, parameters are set carefully, for example, by increasing the frequency of calibration. There is a need.

DESCRIPTION OF SYMBOLS 1 COD density | concentration simulation method 2 Analysis process 3 Correlation of component density | concentration and COD density | concentration 4 Known component COD conversion fractionation process 5 Known component COD density | concentration of inflowing water 6 Refractory COD density | concentration 7 Refractory COD fractionation process 8 Dissolved COD concentration of inflowing water 9 Unidentified component COD concentration of inflowing water 10 Unknown component COD fractionation step 11 Parameter setting step 12 Dissolved oxygen concentration measurement step 13 Predicted known component COD concentration of treated water 14 Predicted treated water Unknown component COD concentration 15 Calculation step 16 COD concentration calculation step of treated water 17 Predicted COD concentration of treated water 21 Oxygen consumption rate test device 22 Microbial sludge 23 Nitrification inhibitor 24 Stirrer 25 Nutrient salt 26 Target component 27 Dissolved oxygen concentration meter 28 Data recording device 29 Air supply device 30 pH meter 31 Acid / alkali supply device 2 heater 33 a constant temperature water bath

Claims (10)

A method for simulating COD concentration in a process of biologically aerobic treatment of aqueous water generated in a coke production process in a biological reaction tank using microorganisms,
An analysis step for measuring and analyzing the concentration of each known component and soluble COD concentration of phenol, thiosulfuric acid, and thiocyan contained in the aqueous solution flowing into the biological reaction tank;
Based on the correlation between each known component concentration and the COD concentration of COD _Cr , COD _Mn, or COD theoretical value, the analysis value of each known component concentration is converted into a COD concentration, thereby obtaining each known component concentration. A known component COD fractionation step for determining the COD concentration of each known component corresponding to
In advance, each of the remaining components of phenol, thiosulfuric acid, and thiocyan remaining in the treated water of the aerobic biologically aerobically treated in the biological reaction tank is measured and analyzed, and the remaining soluble COD concentration is measured and analyzed. Based on the correlation between each remaining known component concentration and the COD concentration of COD _Cr , COD _Mn or COD theoretical value, the COD concentration of each remaining known component corresponding to each remaining known component concentration is determined. A subtractive COD fractionation step for determining the subtractable COD concentration in advance by subtracting the total value of the COD concentrations of the remaining known components from the residual soluble COD concentration;
From the soluble COD concentration obtained in the analysis step, the total value of the COD concentration of each known component obtained in the known component COD fractionation step and the hardly decomposable COD concentration obtained in the hardly decomposable COD fractionation step Subtracting the unknown component fractionation step for determining the unknown component COD concentration contained in the water that flows into the biological reaction tank,
The types and concentrations of microorganisms that decompose phenol, thiosulfuric acid, thiocyanate, and unknown component COD, and the growth yield and reaction rate parameters for the phenol, thiosulfuric acid, thiocyanate, and unknown component COD that are stoichiometric parameters. A parameter setting step for setting a saturation constant and a maximum specific growth rate for the phenol, thiosulfuric acid, thiocyan and unknown component COD;
A dissolved oxygen concentration measuring step for measuring a dissolved oxygen concentration in the biological reaction tank;
Using the known component COD concentration, the unknown component COD concentration, the persistent COD concentration, the growth yield, the saturation constant, the maximum specific growth rate, the type and concentration of the microorganism, and the measured dissolved oxygen concentration Thus, by calculating the calculation formula (1), the remaining known component COD concentration and the remaining unknown component COD concentration in the treated water of the safe water after the biological aerobic treatment in the biological reaction tank are simulated. A calculation process to calculate
A treated water COD concentration calculation step of calculating the remaining soluble COD concentration in the treated water by adding the hardly decomposable COD concentration to the calculated remaining known component COD concentration and remaining unknown component COD concentration. A COD concentration simulation method in a biological aerobic treatment of an aqueous water characterized by comprising:

Where C _{i is the} concentration of each known component COD and the unknown component COD i is a serial number representing the type of each known component COD and unknown component COD P _ij is a stoichiometric parameter j is a serial number representing each process ρ _{j is a} reaction rate equation (Rate equation including reaction rate equation parameters) The parameter setting step includes
(A) In the inflowing water and treated water, the soluble COD concentration, the phenol concentration, the thiosulfuric acid concentration, the thiocyanate concentration, the hardly decomposable COD concentration separately collected in time series in advance, and A method of determining by calibration using unknown component COD concentration and dissolved oxygen concentration,
(B) Using a batch test device that continuously measures the dissolved oxygen concentration using a dissolved oxygen meter, using the microorganisms in the biological reaction tank and the target components in the aqueous solution, oxygen consumption in the oxygen consumption rate test Set parameters using any of the methods determined from the time series data of rate data and soluble COD concentration, phenol concentration, thiosulfate concentration, thiocyan concentration, persistent COD concentration, unknown component COD concentration The COD concentration simulation method in the biological aerobic treatment of the aquatic water according to claim 1, wherein   In the persistent COD fractionation step, a batch test in which microorganisms in the biological reaction tank and the low water were reacted instead of the treated water of biological aerobic treatment in the biological reaction tank The method for simulating COD concentration in biological aerobic treatment of safe water according to claim 1, wherein the persistent COD concentration is determined in advance using treated water afterwards.   The aquatic organism according to any one of claims 1 to 3, wherein the steps are performed by including the phenol in the concentration of the unknown component COD and using the known component as thiosulfuric acid or thiocyan. COD concentration simulation method in biological aerobic treatment.   Using the amount of the inflowing water, the known component COD concentration, the unknown component COD concentration, the time-dependent data of the persistent COD component concentration, and the volume of the biological reaction tank, the calculation is performed. Each known component COD concentration remaining in the treated water of the safe water after the biological aerobic treatment in the biological reaction tank is calculated by calculating the mass balance together with the calculation of the calculation formula (1) in the process. The method for simulating COD concentration in the biological aerobic treatment of aquatic water according to any one of claims 1 to 4, wherein the remaining unknown component COD concentration is calculated by simulation. A COD concentration simulation device in a process of biologically aerobic treatment of aqueous water generated in a coke production process in a biological reaction tank using microorganisms,
Analytical means for measuring and analyzing the concentration of each known component and soluble COD concentration of phenol, thiosulfuric acid, and thiocyan contained in the aqueous solution flowing into the biological reaction tank;
Based on the correlation between each known component concentration and the COD concentration of COD _Cr , COD _Mn, or COD theoretical value, the analysis value of each known component concentration is converted into a COD concentration, thereby obtaining each known component concentration. A known component COD fractionation means for determining the COD concentration of each known component corresponding to
In advance, each of the remaining components of phenol, thiosulfuric acid, and thiocyan remaining in the treated water of the aerobic biologically aerobically treated in the biological reaction tank is measured and analyzed, and the remaining soluble COD concentration is measured and analyzed. Based on the correlation between each remaining known component concentration and the COD concentration of COD _Cr , COD _Mn or COD theoretical value, the COD concentration of each remaining known component corresponding to each remaining known component concentration is determined. And subtractable COD fractionating means for determining the persistent COD concentration in advance by subtracting the total COD concentration of each remaining known component from the remaining soluble COD concentration,
The total COD concentration of each known component obtained by the known component COD fractionation means from the soluble COD concentration obtained by the analysis means, and the hardly decomposable COD concentration obtained by the hardly decomposable COD fractionation means Subtracting the unknown component fractionation means for determining the unknown component COD concentration contained in the water that flows into the biological reaction tank,
The types and concentrations of microorganisms that decompose phenol, thiosulfuric acid, thiocyanate, and unknown component COD, and the growth yield and reaction rate parameters for the phenol, thiosulfuric acid, thiocyanate, and unknown component COD that are stoichiometric parameters. Parameter setting means for setting a saturation constant for the phenol, thiosulfuric acid, thiocyan and unknown component COD, and a maximum specific growth rate;
A dissolved oxygen concentration measuring means for measuring a dissolved oxygen concentration in the biological reaction tank;
Using the known component COD concentration, the unknown component COD concentration, the persistent COD concentration, the growth yield, the saturation constant, the maximum specific growth rate, the type and concentration of the microorganism, and the measured dissolved oxygen concentration Thus, by calculating the calculation formula (1), the remaining known component COD concentration and the remaining unknown component COD concentration in the treated water of the safe water after the biological aerobic treatment in the biological reaction tank are simulated. Calculating means for calculating
A treated water COD concentration calculating means for calculating the remaining soluble COD concentration in the treated water by adding the hardly decomposable COD concentration to the calculated remaining known component COD concentration and remaining unknown component COD concentration. A COD concentration simulation apparatus for biological aerobic treatment of aquatic water characterized by comprising:

Where C _{i is the} concentration of each known component COD and the unknown component COD i is a serial number representing the type of each known component COD and unknown component COD P _ij is a stoichiometric parameter j is a serial number representing each process ρ _{j is a} reaction rate equation (Rate equation including reaction rate equation parameters) The parameter setting means includes
(A) In the inflowing water and treated water, the soluble COD concentration, the phenol concentration, the thiosulfuric acid concentration, the thiocyanate concentration, the hardly decomposable COD concentration separately collected in time series in advance, and An apparatus that uses unknown component COD concentration and dissolved oxygen concentration to determine by calibration,
(B) Using a batch test device that continuously measures the dissolved oxygen concentration using a dissolved oxygen meter, using the microorganisms in the biological reaction tank and the target components in the aqueous solution, oxygen consumption in the oxygen consumption rate test Set parameters using any one of the devices determined from the time series data of rate data and soluble COD concentration, phenol concentration, thiosulfate concentration, thiocyan concentration, persistent COD concentration, unknown component COD concentration The apparatus for simulating COD concentration in the biological aerobic treatment of aquatic water according to claim 6, wherein:   In the persistent COD fractionation means, a batch test in which microorganisms in the biological reaction tank and the low water were reacted instead of the treated water of biological aerobic treatment in the biological reaction tank The apparatus for simulating COD concentration in biological aerobic treatment of safe water according to claim 6 or 7, wherein the persistent COD concentration is determined in advance using treated water afterwards.   The aquatic organism according to any one of claims 6 to 8, wherein said means is implemented by including said phenol in said unknown component COD concentration and said known component as thiosulfuric acid or thiocyan. COD concentration simulation device for biological aerobic treatment.   Using the amount of the inflowing water, the known component COD concentration, the unknown component COD concentration, the time-dependent data of the persistent COD component concentration, and the volume of the biological reaction tank, the calculation is performed. By calculating the mass balance together with the calculation of the calculation formula (1) in the means, the concentration of each known component COD remaining in the treated water of the aqueous water after the biological aerobic treatment in the biological reaction tank 10. The COD concentration simulation apparatus for biological aerobic treatment of aquatic water according to any one of claims 6 to 9, wherein the remaining unknown component COD concentration is calculated by simulation.

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