Automatic control method based on the mechanism model of catalytic oxidation of odorous substances by ultraviolet hydrogen peroxide

Abstract

The automatic control method based on the mechanism model of ultraviolet hydrogen peroxide catalytic oxidation of odorous substances includes: Step 1, data collection; Step 2, simulation prediction; establish the mechanism model of ultraviolet hydrogen peroxide catalytic oxidation of odorous substances, dynamically simulate the generation and consumption of hydroxyl radicals, solve a series of ordinary differential equations in the model, obtain the dynamic concentration of the model variables, and when the system reaches a steady state, various concentration variables converge to the steady-state concentration; Step 3, according to the mechanism model obtained in Step 2, use the data collected in Step 1, set constraints and objective functions, adjust the prediction time domain and control time domain, and obtain the minimum operating cost under the premise that the effluent concentration of the target pollutant meets the standard. By establishing a model-based predictive control system, the effluent water quality and operating cost can be predicted according to the water quality and water volume of the influent, and the optimal hydrogen peroxide concentration and ultraviolet lamp power can be found, so as to automatically adjust the hydrogen peroxide dosage and the ultraviolet lamp opening rate, and achieve the optimization of operating costs based on the water quality meeting the standard.

Description

Technical Field

[0001] The invention relates to the technical field of water treatment, and in particular to an automatic control method based on a mechanism model of ultraviolet hydrogen peroxide catalytic oxidation of odorous substances. Background Art

[0002] The UV / H2O2 catalytic oxidation technology for tap water is one of the few methods that can effectively remove new pollutants from tap water, but its reaction mechanism and kinetic process are complex, and the treatment effect is challenged by fluctuations in water quality and quantity. There are many variables that affect the effect of UV / H2O2 catalytic oxidation treatment, including water volume, and influent water quality (target odor substance concentration (Geosmim, 2-MIB, pH, total organic carbon, total organic matter, total inorganic carbon, nitrate, nitrite, etc.). These variables interact with each other in the treatment results. If the operator's experience is relied on, it is difficult to dynamically adjust the two operating parameters of hydrogen peroxide dosage and UV power according to these changing variables. However, the UV / H2O2 catalytic oxidation process is sensitive to these two operating parameters. Excessive addition of hydrogen peroxide will result in excessively high residual hydrogen peroxide concentration in the effluent and fail to meet the standard, and insufficient addition of hydrogen peroxide will result in odor substances in the effluent failing to meet the standard. Too high UV power will lead to excessively high operating costs, and too low power will also fail to meet the treatment requirements.

[0003] Traditional PID feedback control is a widely used automatic control technology in the industrial sector. To use it in the UV hydrogen peroxide catalytic oxidation process of water plants requires an online odorant concentration signal. The concentration of odorants is extremely low, and even in the laboratory, it requires high-precision instruments and experienced testers to accurately measure its concentration. There is currently no commercially available online sensor for odorants, making PID feedback control unfeasible. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an automatic control method based on the mechanism model of ultraviolet hydrogen peroxide catalytic oxidation of odorous substances, accurately control the dosage of hydrogen peroxide and the opening degree of the ultraviolet lamp, and find the optimal solution for achieving water quality standards and saving energy and chemicals.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] The automatic control method based on the mechanism model of ultraviolet hydrogen peroxide catalytic oxidation of odor substances includes: Step 1, data acquisition; including the acquisition of basic data, online sensor water quality data and offline detection water quality data;

[0007] Step 2, simulation prediction; establish a mechanism model of ultraviolet hydrogen peroxide catalytic oxidation of odor substances, dynamically simulate the generation and consumption of hydroxyl radicals, and obtain the dynamic concentration of model variables by solving a series of ordinary differential equations in the model. When the system reaches a steady state, various concentration variables converge to the steady-state concentration;

[0008] Step 3. According to the mechanism model obtained in Step 2, use the data collected in Step 1 to set constraints and objective functions, adjust the prediction time domain and control time domain, and obtain the minimum operating cost under the premise that the effluent concentration of target odorous substances meets the standard.

[0009] In the above Step 3, the constraints are: the effluent water quality reaches the user-set target and the hydrogen peroxide concentration does not exceed the user-set value; the objective function is the operating cost.

[0010] The basic data in the above Step 1 include the set target odor substance control concentration, hydrogen peroxide concentration, unit price and electricity unit price;

[0011] The above-mentioned online sensor water quality data include water flow, pH, temperature, hydrogen peroxide flow, and ultraviolet light intensity;

[0012] The above-mentioned offline water quality detection data include influent odor substances, total organic carbon, total inorganic carbon, nitrate and nitrite concentrations.

[0013] In the above-mentioned Step 2 ultraviolet hydrogen peroxide catalytic oxidation mechanism model of odorous substances, odorous substances are removed by direct ultraviolet oxidation and indirect oxidation by hydroxyl radicals. Indirect oxidation utilizes hydroxyl radicals produced by ultraviolet catalytic oxidation of hydrogen peroxide. The degradation rate of odorous substances is related to the concentration of hydroxyl radicals.

[0014] The establishment process of the mechanism model of ultraviolet hydrogen peroxide catalytic oxidation of odorous substances in the above Step 2 is as follows:

[0015] The mechanism model includes 9 dynamic reactions, namely 2 degradation reactions of odor substances: direct degradation of odor substances by UV rays - formula (1) and indirect degradation of odor substances by hydroxyl radicals - formula (4), as well as 1 hydroxyl radical generation reaction - formula (2-3) and 6 hydroxyl radical competitive consumption reactions - formula (5-10):

[0016] In the direct degradation reaction of odor substances by ultraviolet, the degradation rate of odor substance concentration C and the ultraviolet light intensity I0 and ultraviolet light quantum efficiency φ c , total UV absorbance A t And the proportion of the absorbance of the target odor substance f C Related:

[0017]

[0018] In the indirect degradation of odor substances by hydroxyl radicals, one molecule of hydrogen peroxide is cleaved under ultraviolet light to produce two molecules of hydroxyl radicals, that is, formula (2); the cleavage rate of hydrogen peroxide is and UV light intensity I0, UV light quantum efficiency φ H2O2 , total UV absorbance A t , the proportion of hydrogen peroxide absorbance f H2O2 Related, that is, formula (3):

[0019]

[0020] The degradation rate of bromine in odor substances follows a first-order kinetic reaction, and its degradation rate and hydroxyl radical concentration C HO and soil bromide concentration C geosmin Proportional to k HO，geosmin is the rate constant for the degradation of tert-butyl bromide by hydroxyl radicals:

[0021]

[0022] According to the chemical composition and corresponding reaction rates in tap water, six competitive side reactions that consume hydroxyl radicals were screened, including hydroxyl radicals consumed by organic matter reduction - formula (5), hydroxyl radicals consumed by hydrogen peroxide and hydrogen peroxide - formula (6-7), hydroxyl radicals consumed by carbonate and bicarbonate - formula (8-9), and hydroxyl radicals consumed by nitrite reduction - formula (10);

[0023] Hydroxyl radicals are consumed by dissolved organic matter (DOC) in natural water bodies at a rate of and the consumption rate constant F Scav , hydroxyl radical concentration C HO.dot and the concentration of dissolved organic matter C DOC , reference conditions, that is, the concentration of dissolved organic matter under reference conditions C DOC，ref Related:

[0024]

[0025] Hydroxyl radicals are consumed by hydrogen peroxide at a rate of and the consumption rate constant k HO.dot，H2O2 , hydroxyl radical concentration C HO.dot And the concentration of hydrogen peroxide C H2O2 Related:

[0026]

[0027] Hydroxyl radicals are consumed by hydrogen peroxide at a rate of and the consumption rate constant k HO.dot，HO2 , hydroxyl radical concentration C HO.dot and the hydrogen peroxide concentration C HO2 Related:

[0028]

[0029] Hydroxyl radicals are consumed by carbonate ions at a rate of and the consumption rate constant k HO.dot，CO3 , hydroxyl radical concentration C HO.dot and the carbonate concentration C CO3 Related:

[0030]

[0031] Hydroxyl radicals are consumed by bicarbonate at a rate of and the consumption rate constant k HO.dot，HCO3 , hydroxyl radical concentration C HO.dot and bicarbonate concentration C HCO3 Related:

[0032]

[0033] Hydroxyl radicals are consumed by nitrite (nitration reaction), and the consumption rate is and the consumption rate constant k HO.dot，NO2 , hydroxyl radical concentration C HO.dot and nitrite concentration C NO2 Related:

[0034]

[0035] The 9 dynamic reactions of the mechanism model of ultraviolet hydrogen peroxide catalytic oxidation of odor substances in Step 2 above also include calibration:

[0036] First, calibrate the parameters of UV direct oxidation of odor substances, namely the UV quantum efficiency φ c , UV direct degradation involves only one chemical reaction, not hydrogen peroxide and hydroxyl radicals, so it can be independently calibrated without adding hydrogen peroxide;

[0037] Secondly, in the calibration of indirect degradation reaction parameters, through sensitivity analysis, variables and parameters with relative sensitivity higher than the set value are screened out, and they are tested and calibrated, including the rate constant of odor substances being degraded by hydroxyl radicals, pH in the reactor, hydrogen peroxide concentration, ultraviolet light intensity, inorganic carbon concentration, ultraviolet absorbance and flow rate; pH and flow rate in the reactor are obtained through online instruments, hydrogen peroxide concentration and ultraviolet light intensity are controllable variables, and inorganic carbon concentration and ultraviolet absorbance are obtained in laboratory test sampling;

[0038] Finally, the rate constant of odor substances degradation by hydroxyl radicals was obtained by fitting the experimental data.

[0039] The present invention provides an automatic control method based on a mechanism model of ultraviolet hydrogen peroxide catalytic oxidation of odorous substances. The mechanism model of the ultraviolet hydrogen peroxide catalytic oxidation process is excavated, and a prediction control system based on the model is established. The water quality and operating cost of the outlet water can be predicted according to the water quality and quantity of the inlet water, and the optimal hydrogen peroxide concentration and ultraviolet lamp power can be found, thereby automatically adjusting the hydrogen peroxide dosage and the ultraviolet lamp opening rate, so as to achieve the optimization of the operating cost on the basis of meeting the water quality standards. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0041] Figure 1 It is a structural module of the method of the present invention;

[0042] Figure 2 It is the mechanism model structure of the present invention;

[0043] Figure 3 The water volume and water quality of the inlet water in the embodiment of the present invention;

[0044] Figure 4 is the concentration of geosmin in the inlet and outlet water in the two manual modes and the automatic mode of the embodiment of the present invention;

[0045] Figure 5 is the concentration of dimethyl isocyanate in the inlet and outlet water in the two manual modes and the automatic mode of the embodiment of the present invention;

[0046] Figure 6 It is the operating cost in two manual modes and automatic mode of the embodiment of the present invention. DETAILED DESCRIPTION

[0047] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings and embodiments.

[0048] The automatic control method based on the mechanism model of ultraviolet hydrogen peroxide catalytic oxidation of odor substances includes: Step 1, data acquisition; including the acquisition of basic data, online sensor water quality data and offline detection water quality data;

[0049] Step 2, simulation prediction; establish a mechanism model of ultraviolet hydrogen peroxide catalytic oxidation of odor substances, dynamically simulate the generation and consumption of hydroxyl radicals, and obtain the dynamic concentration of model variables by solving a series of ordinary differential equations in the model. When the system reaches a steady state, various concentration variables converge to the steady-state concentration;

[0050] Step 3. According to the mechanism model obtained in Step 2, use the data collected in Step 1 to set constraints and objective functions, adjust the prediction time domain and control time domain, and obtain the minimum operating cost under the premise that the effluent concentration of target odorous substances meets the standard.

[0051] In the above Step 3, the constraints are: the effluent water quality reaches the user-set target and the hydrogen peroxide dosing concentration does not exceed the user-set value; the objective function is the operating cost.

[0052] The basic data in the above Step 1 include the set target odor substance control concentration, hydrogen peroxide concentration, unit price and electricity unit price;

[0053] The above-mentioned online sensor water quality data include water flow, pH, temperature, hydrogen peroxide flow, and ultraviolet light intensity;

[0054] The above-mentioned offline water quality detection data include influent odor substances, total organic carbon, total inorganic carbon, nitrate and nitrite concentrations.

[0055] In the above-mentioned Step 2 ultraviolet hydrogen peroxide catalytic oxidation odorous substances mechanism model, odorous substances are removed by direct ultraviolet oxidation and indirect oxidation by hydroxyl radicals. Indirect oxidation utilizes hydroxyl radicals produced by ultraviolet catalytic oxidation of hydrogen peroxide, and the degradation rate of odorous substances is related to the concentration of hydroxyl radicals. Hydroxyl radicals are strong oxidants with poor selectivity. They can compete with various substances in water, such as hydrogen peroxide, organic matter, nitrite, carbonate, bicarbonate, etc., to consume hydroxyl radicals. This model dynamically simulates the generation and consumption of hydroxyl radicals. The program is written in Python language, and the dynamic concentration of model variables is obtained by solving a series of ordinary differential equations. When the system reaches a steady state, various concentration variables converge to the steady-state concentration. Through this program, the odor concentration of the effluent after ultraviolet catalytic oxidation treatment, the cost of hydrogen peroxide and the electricity cost, that is, the cost of using ultraviolet lamps, can be simulated and calculated.

[0056] In the above Step 3, by adjusting the prediction time domain and the control time domain, the optimal combination of hydrogen peroxide concentration and ultraviolet light intensity can be stably and quickly predicted. This combination can be used to control the hydrogen peroxide pump and ultraviolet lamp in real time by using traditional PID technology, thereby achieving the lowest operating cost under the premise that the effluent concentration of target pollutants such as bromide and dimethyl isoborneol meets the standards; this model-based control achieves self-control by predicting the effluent water quality, avoids dependence on odorous substance sensors, and realizes feedforward control.

[0057] The establishment process of the mechanism model of ultraviolet hydrogen peroxide catalytic oxidation of odorous substances in the above Step 2 is as follows:

[0058] The mechanism model includes 9 dynamic reactions, namely 2 degradation reactions of odor substances: direct degradation of odor substances by UV rays - formula (1) and indirect degradation of odor substances by hydroxyl radicals - formula (4), as well as 1 hydroxyl radical generation reaction - formula (2-3) and 6 hydroxyl radical competitive consumption reactions - formula (5-10):

[0059] In the direct degradation reaction of odor substances by ultraviolet, the degradation rate of odor substance concentration C and the ultraviolet light intensity I0 and ultraviolet light quantum efficiency φ c , total UV absorbance A t And the proportion of the absorbance of the target odor substance f C Related:

[0060]

[0061] In the indirect degradation of odor substances by hydroxyl radicals, one molecule of hydrogen peroxide is cleaved under ultraviolet light to produce two molecules of hydroxyl radicals, that is, formula (2); the cleavage rate of hydrogen peroxide is and UV light intensity I0, UV light quantum efficiency φ H2O2 , total UV absorbance A t , the proportion of hydrogen peroxide absorbance f H2O2 Related, that is, formula (3):

[0062]

[0063]

[0064] The degradation rate of bromine in odor substances follows a first-order kinetic reaction, and its degradation rate and hydroxyl radical concentration C HO and soil bromide concentration C geosmin Proportional to k HO，geosmin is the rate constant for the degradation of tert-butyl bromide by hydroxyl radicals:

[0065]

[0066] According to the chemical composition and corresponding reaction rates in tap water, six competitive side reactions that consume hydroxyl radicals were screened, including hydroxyl radicals consumed by organic matter reduction - formula (5), hydroxyl radicals consumed by hydrogen peroxide and hydrogen peroxide - formula (6-7), hydroxyl radicals consumed by carbonate and bicarbonate - formula (8-9), and hydroxyl radicals consumed by nitrite reduction - formula (10);

[0067] Hydroxyl radicals are consumed by dissolved organic matter (DOC) in natural water bodies at a rate of and the consumption rate constant F Scav , hydroxyl radical concentration C HO.dot and the concentration of dissolved organic matter C DOC , reference conditions, that is, the concentration of dissolved organic matter under reference conditions C DOC，ref Related:

[0068]

[0069] Hydroxyl radicals are consumed by hydrogen peroxide at a rate of and the consumption rate constant k HO.dot，H2O2 , hydroxyl radical concentration C HO.dot And the concentration of hydrogen peroxide C H2O2 Related:

[0070]

[0071] Hydroxyl radicals are consumed by hydrogen peroxide at a rate of and the consumption rate constant k HO.dot，HO2 , hydroxyl radical concentration C HO.dot and the hydrogen peroxide concentration C HO2 Related:

[0072]

[0073] Hydroxyl radicals are consumed by carbonate ions at a rate of and the consumption rate constant k HO.dot，CO3 , hydroxyl radical concentration C HO.dot and the carbonate concentration C CO3 Related:

[0074]

[0075] Hydroxyl radicals are consumed by bicarbonate at a rate of and the consumption rate constant k HO.dot，HCO3 , hydroxyl radical concentration C HO.dot and bicarbonate concentration C HCO3 Related:

[0076]

[0077] Hydroxyl radicals are consumed by nitrite (nitration reaction), and the consumption rate is and the consumption rate constant k HO.dot，NO2 , hydroxyl radical concentration C HO.dot and nitrite concentration C NO2 Related:

[0078]

[0079] The nine dynamic reactions of the mechanism model of UV hydrogen peroxide catalytic oxidation of odor substances in Step 2 above have many parameters and are interrelated. In order to reduce the difficulty of calibration, the following calibration process was developed:

[0080] First, calibrate the parameters of UV direct oxidation of odor substances, namely the UV quantum efficiency φ c, UV direct degradation involves only one chemical reaction, not hydrogen peroxide and hydroxyl radicals, so it can be independently calibrated without adding hydrogen peroxide;

[0081] Secondly, in the calibration of indirect degradation reaction parameters, through sensitivity analysis, variables and parameters with relative sensitivity higher than the set value of 0.25 were screened out, and they were tested and calibrated, including the rate constant of odor substances being degraded by hydroxyl radicals, pH in the reactor, hydrogen peroxide concentration, ultraviolet light intensity, inorganic carbon concentration, ultraviolet absorbance, and flow rate; pH and flow rate in the reactor were obtained through online instruments, hydrogen peroxide concentration and ultraviolet light intensity were controllable variables, and inorganic carbon concentration and ultraviolet absorbance were obtained in laboratory test sampling;

[0082] Finally, the rate constant of odor substances degradation by hydroxyl radicals was obtained by fitting the experimental data.

[0083] like Figure 3-6 As shown in, it is a data chart of the actual simulation process of the present invention, simulating two manual operation modes, namely, constant hydrogen peroxide dosing concentration and constant hydrogen peroxide dosing flow rate and the model automatic control mode of the present invention; under the same inlet water quality and water quantity conditions, Figure 3 The simulation runs for 50 days. After using the automatic control mode, the geosmin compliance rate increased from 93% and 99% to 100%. Figure 4 As shown in Figure 2, the compliance rate of dimethyl isocyanate increased from 63% and 79% to 91%. Figure 5 As shown, the cost of hydrogen peroxide and electricity dropped from 0.274 and 0.306 to 0.250 yuan per cubic meter. Figure 6 shown.

Claims

1. An automatic control method based on the mechanism model of ultraviolet hydrogen peroxide catalytic oxidation of odorous substances, characterized in that: include: Step 1, data collection; Includes collection of basic data, online sensor water quality data, and offline detection water quality data; Step 2, simulation prediction; establish a mechanism model for the catalytic oxidation of odor substances by ultraviolet hydrogen peroxide, and include 9 dynamic reactions in the mechanism model; In the direct degradation reaction of odor substances by ultraviolet, the degradation rate of odor substance concentration C is related to the ultraviolet light intensity I0 and the ultraviolet light quantum efficiency. Total UV absorbance A t And the proportion of the absorbance of the target odor substance f C Related: In the indirect degradation of odor substances by hydroxyl radicals, one molecule of hydrogen peroxide is cleaved under ultraviolet light to produce two molecules of hydroxyl radicals, that is, formula (2); the cleavage rate of hydrogen peroxide is And ultraviolet light intensity I0, ultraviolet light quantum efficiency II Total UV absorbance A t , the proportion of hydrogen peroxide absorbance f H2O2 Related, that is, formula (3): The degradation rate of bromine in odor substances follows a first-order kinetic reaction, and its degradation rate and hydroxyl radical concentration C HO.dot and soil bromide concentration C geosmin Proportional to k HO,geosmin is the rate constant for the degradation of tert-butyl bromide by hydroxyl radicals: According to the chemical composition and corresponding reaction rates in tap water, six side reactions that competitively consume hydroxyl radicals were screened; Hydroxyl radicals are consumed by dissolved organic matter (DOC) in natural water bodies at a rate of and the consumption rate constant F Scav , hydroxyl radical concentration C HO.dot , and dissolved organic matter concentration C DOC Related: Hydroxyl radicals are consumed by hydrogen peroxide at a rate of and the consumption rate constant k HO.dot,H2O2 , hydroxyl radical concentration C HO.dot And the concentration of hydrogen peroxide C H2O2 Related: Hydroxyl radicals are consumed by hydrogen peroxide at a rate of and the consumption rate constant k HO.dot,HO2 , hydroxyl radical concentration C HO.dot and the hydrogen peroxide concentration C HO2 Related: Hydroxyl radicals are consumed by carbonate ions at a rate of and the consumption rate constant k HO.dot,CO3 , hydroxyl radical concentration C HO.dot and the carbonate concentration C CO3 Related: Hydroxyl radicals are consumed by bicarbonate at a rate of and the consumption rate constant k HO.dot,HCO3 , hydroxyl radical concentration C HO.dot and bicarbonate concentration C HCO3 Related: Hydroxyl radicals are consumed by nitrite at a rate of and the consumption rate constant k HO.dot,NO2 , hydroxyl radical concentration C HO.dot and nitrite concentration C NO2 Related: Step 3. According to the mechanism model obtained in Step 2, use the data collected in Step 1 to set constraints and objective functions, adjust the prediction time domain and control time domain, and obtain the minimum operating cost under the premise that the effluent concentration of target odorous substances meets the standard.

2. The automatic control method based on the mechanism model of ultraviolet hydrogen peroxide catalytic oxidation of odor substances according to claim 1 is characterized in that: In the Step 3, the constraints are: the effluent water quality reaches the user-set target and the hydrogen peroxide dosing concentration does not exceed the user-set value; the objective function is the operating cost.

3. The automatic control method based on the mechanism model of ultraviolet hydrogen peroxide catalytic oxidation of odor substances according to claim 2 is characterized in that: The basic data in Step 1 include the set target odor substance control concentration, hydrogen peroxide concentration, unit price and electricity unit price; The online sensor water quality data includes water flow, pH, temperature, hydrogen peroxide flow and ultraviolet light intensity; The offline water quality detection data include the concentrations of influent odor substances, total organic carbon, total inorganic carbon, nitrate and nitrite.

4. The automatic control method based on the mechanism model of ultraviolet hydrogen peroxide catalytic oxidation of odor substances according to claim 3 is characterized in that: In the Step 2 ultraviolet hydrogen peroxide catalytic oxidation mechanism model, the odorous substances are removed by direct ultraviolet oxidation and indirect oxidation by hydroxyl radicals. Indirect oxidation utilizes hydroxyl radicals generated by ultraviolet catalytic oxidation of hydrogen peroxide. The degradation rate of the odorous substances is related to the concentration of hydroxyl radicals.

5. The automatic control method based on the mechanism model of ultraviolet hydrogen peroxide catalytic oxidation of odor substances according to claim 4 is characterized in that The nine dynamic reactions of the mechanism model of ultraviolet hydrogen peroxide catalytic oxidation of odor substances in Step 2 also include calibration: First, calibrate the parameters of UV direct oxidation of odor substances, that is, UV quantum efficiency -φ c , UV direct degradation involves only one chemical reaction, not hydrogen peroxide and hydroxyl radicals, so it can be independently calibrated without adding hydrogen peroxide; Secondly, in the calibration of indirect degradation reaction parameters, through sensitivity analysis, variables and parameters with relative sensitivity higher than the set value are screened out, and they are tested and calibrated, including the rate constant of odor substances being degraded by hydroxyl radicals, pH in the reactor, hydrogen peroxide concentration, ultraviolet light intensity, inorganic carbon concentration, ultraviolet absorbance and flow rate; pH and flow rate in the reactor are obtained through online instruments, hydrogen peroxide concentration and ultraviolet light intensity are controllable variables, and inorganic carbon concentration and ultraviolet absorbance are obtained in laboratory test sampling; Finally, the rate constant of odor substances degradation by hydroxyl radicals was obtained by fitting the experimental data.

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