A method for rapidly predicting the catalytic degradation rate of organic pollutants in a peroxymonosulfate non-radical degradation system

Abstract

The present invention provides a method for rapidly predicting the catalytic degradation rate of organic pollutants in a peroxymonosulfate non-radical degradation system, and relates to the technical field of water treatment and environmental catalysis. The present invention uses common FCO as a model catalyst, and uses FCO to activate PMS to construct an FCO / PMS catalytic oxidation system. By measuring the voltammetric curves of different pollutants, it is found that in the FCO / PMS catalytic oxidation system, the degradation rate constants of different organic substances are negatively correlated with the half-wave potential, and the model equation is #imgabs0# where R 2 =0.697. Based on the first-order degradation model, the present invention introduces a catalytic degradation rate model of organic pollutants in a peroxymonosulfate non-radical degradation system and its expression form, providing theoretical support for rapid evaluation of organic pollutant removal capacity.

Description

Technical Field

[0001] The invention relates to the technical field of water treatment and environmental catalysis, and in particular to a method for rapidly predicting the catalytic degradation rate of organic pollutants in a peroxymonosulfate non-free radical degradation system. Background Art

[0002] With the continuous growth of the global population and the rapid development of industry, organic substances such as agricultural chemicals, dyes and medicines are accelerating their penetration into natural water bodies, making surface water and groundwater sources full of organic pollutants. The total amount of clean water resources is constantly decreasing, and the phenomenon of water pollution is aggravated, which seriously affects the health of organisms. In addition, since some organic pollutants are difficult to degrade, easy to bioaccumulate and widely distributed, they have caused great harm to the environment and seriously affected the life and health of the people. Therefore, how to remove organic pollutants from water bodies has become a hot topic of research. Under natural conditions, even at low concentration levels, organic pollutants can have potential or direct effects on humans, animals and plants, so it is crucial to develop environmentally friendly, energy-saving and low-cost sustainable water purification technologies.

[0003] At present, the advanced oxidation technology based on activated persulfate is favored because of its strong oxidizing ability, short reaction time, wide application range, low secondary pollution and flexible and simple operation. In recent years, it has been widely used in the degradation of organic pollutants in water systems. 1 O2) and other non-free radicals act on pollutant molecules, thereby promoting the oxidative decomposition of pollutants, and even mineralizing them into carbon dioxide and water or other small molecules. However, a key challenge is that most organic pollutants have complex molecular structures and weak biodegradability. The common catalysts in the past have many limitations. Another key challenge is that the actual wastewater composition is complex and diverse, and there may be a variety of organic pollutants and other coexisting ions. Their concentrations may be several orders of magnitude higher than the target pollutants, resulting in a large consumption of active species or the generation of low-activity groups. Therefore, it is necessary to develop a model that can quickly predict the catalytic degradation rate of organic pollutants. Summary of the invention

[0004] The purpose of the present invention is to provide a method for quickly predicting the catalytic degradation rate of organic pollutants in a peroxymonosulfate non-radical degradation system. The present invention uses common iron-cobalt composite oxide (FCO) as a model catalyst, and uses FCO to activate peroxymonosulfate (PMS) to construct an FCO / PMS catalytic oxidation system. By measuring the voltammetric curves of different pollutants, it is found that in the FCO / PMS catalytic oxidation system, the degradation rate constants K of different pollutants are obs Cyclic voltammetry (CV) and half-wave potential Cyclic voltammetry (CV) curves can be used to identify the redox potential of pollutants, and the half-wave potential of different pollutants It can be calculated from the redox peak in the cyclic voltammetry curve of the pollutant, which can represent the redox properties of the pollutant. The degradation rate constant K of different organic matter obs With half-wave potential Negatively correlated, the model equation is Where R 2 =0.697. Based on the first-order degradation model, the present invention introduces a catalytic degradation rate model of organic pollutants in a peroxymonosulfate non-radical degradation system and its expression form, providing theoretical support for rapid evaluation of organic pollutant removal capacity.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a method for rapidly predicting the catalytic degradation rate of organic pollutants in a peroxymonosulfate non-radical degradation system, comprising the following steps:

[0007] S1: Activate peroxymonosulfate with a model catalyst to construct a FCO / PMS catalytic oxidation system;

[0008] S2: testing cyclic voltammetry curves of different organic pollutants in the FCO / PMS catalytic oxidation system;

[0009] S3: Calculate the half-wave potential of different organic pollutants based on the cyclic voltammetry curves of different organic pollutants tested;

[0010] S4: Calculating the degradation rate constants of different organic pollutants based on the half-wave potentials of the different organic pollutants.

[0011] Further, based on the above technical solution, in step S4, the model equation for calculating the degradation rate constants of different organic pollutants is:

[0012]

[0013] Among them, K obs is the degradation rate constant; is the half-wave potential;

[0014] The R of the model equation 2 =0.697.

[0015] Furthermore, based on the above technical solution, in step S1, the model catalyst is an iron-cobalt composite oxide FCO.

[0016] Further, based on the above technical solution, the preparation method of the model catalyst comprises the following steps:

[0017] (1) dissolving an iron salt and a cobalt salt in an alkaline solvent, and stirring at room temperature until a dark brown turbidity appears to obtain a mixture;

[0018] (2) transferring the mixture into a polytetrafluoroethylene reactor and performing a hydrothermal reaction at 390-470 K for 4-8 h;

[0019] Preferably, the hydrothermal reaction is carried out at 433 K for 6 h;

[0020] (3) After cooling to room temperature, the obtained solid was washed with ethanol and ultrapure water for multiple times, and dried at 350-400 K for 4-8 h to obtain a model catalyst;

[0021] Preferably, drying is carried out at 378 K for 6 h.

[0022] Further, based on the above technical solution, the molar ratio of the iron salt to the cobalt salt is (0-4): (0-4), wherein the iron salt and the cobalt salt are not zero at the same time;

[0023] And / or, the iron salt is one of ferric nitrate, ferric chloride or ferric acetylacetonate;

[0024] And / or, the cobalt salt is one of cobalt nitrate, cobalt chloride or cobalt acetylacetonate;

[0025] And / or, the alkaline solvent is 2-6 mol of one of sodium hydroxide, potassium hydroxide, calcium hydroxide or ammonia solution;

[0026] And / or, the stirring is ultrasonic and glass rod mixed stirring;

[0027] Preferably, the stirring conditions are: temperature of 20-40°C, preferably 25°C, and stirring time of 30-60 min.

[0028] Further, based on the above technical solution, in step S1, constructing the FCO / PMS catalytic oxidation system includes the following steps:

[0029] S11: placing different organic pollutants in a container, stirring, and adjusting the pH to obtain an initial solution;

[0030] S12: placing the FCO catalyst in the initial solution, adjusting the pH of the water, stirring, and then adding sulfate to perform a catalytic oxidation reaction to obtain a FCO / PMS catalytic oxidation system.

[0031] Further, based on the above technical solution, in step S11,

[0032] The stirring conditions are: temperature of 20-30°C, stirring time of 10-20min;

[0033] and / or, adjusting the pH of the water body using 1 mol / L H2SO4 solution and 1 mol / L NaOH solution;

[0034] Preferably, the pH is 3-11;

[0035] and / or, the organic contaminants include one or more of crystalline amoxicillin, cephalexin hydrate, ciprofloxacin, levofloxacin, 4-acetamidephenol, carbamazepine, metronidazole, sulfamethoxazole, bisphenol, benzoic acid, sulfadiazine, and naproxen;

[0036] And / or, the concentration of the organic pollutants is 1-7 mg / L, preferably 3-5 mg / L.

[0037] Further, based on the above technical solution, in step S12,

[0038] The stirring conditions are: stirring time is 5-15min, temperature is 20-30°C;

[0039] and / or, pH 3-11;

[0040] And / or, in step S12, the sulfate is potassium permonosulfate PMS;

[0041] Preferably, the concentration of the potassium permonosulfate PMS is 0.01 mmol-0.02 mmol.

[0042] Further, based on the above technical solution, in step S2, testing the cyclic voltammetry curves of different organic pollutants includes:

[0043] When the reaction time is 1 min, 2 min, 3 min, 4 min, 5 min, 7 min, and 10 min, the catalytic oxidation reaction liquid obtained in step S13 is sucked out through the filter membrane for quenching; the quenched reaction liquid is used to test the cyclic voltammetry curves of different organic pollutants;

[0044] And / or, the quenching agent comprises one or more of methanol, tert-butyl alcohol, p-benzoquinone and furfuryl alcohol;

[0045] Preferably, the quenching agent is methanol;

[0046] Preferably, the amount of methanol is 0.3-0.7 mL;

[0047] Preferably, the amount of methanol used is 0.5 mL.

[0048] Further, based on the above technical solution, in step S3, the half-wave potential of different organic pollutants is calculated. The equation is:

[0049]

[0050] Among them, E P is the potential of the peak current of the cyclic voltammetry curve;

[0051] E P / 2 is the potential of the half-peak current of the cyclic voltammetry curve.

[0052] The present invention provides a method for rapidly predicting the catalytic degradation rate of organic pollutants in a peroxymonosulfate non-radical degradation system, and the beneficial effects are as follows:

[0053] 1. The present invention uses common iron-cobalt composite oxide (FCO) as a model catalyst, and uses FCO to activate persulfate (PMS) to construct an FCO / PMS catalytic oxidation system. By measuring the voltammetric curves of different pollutants, it is found that in the FCO / PMS catalytic oxidation system, the degradation rate constants K of different pollutants are obs Cyclic voltammetry (CV) and half-wave potential Cyclic voltammetry (CV) curves can be used to identify the redox potential of pollutants, and the half-wave potential of different pollutants It can be calculated from the redox peak in the cyclic voltammetry curve of the pollutant, which can represent the redox properties of the pollutant. Degradation rate constant Kobs and half-wave potential of different organic matter Negatively correlated, the model equation is Where R 2 =0.697. Based on the first-order degradation model, the present invention introduces a catalytic degradation rate model of organic pollutants in a peroxymonosulfate non-radical degradation system and its expression form, providing theoretical support for rapid evaluation of organic pollutant removal capacity.

[0054] 2. The selective oxidation catalyst iron-cobalt composite oxide described in the present invention can give full play to the high activation effect of the catalyst, accelerate the reaction process, and avoid the transportation of high-risk oxidants such as hydrogen peroxide. Compared with conventional perovskite catalysts, ozone advanced oxidation, electrocatalysis, photocatalysis and other methods, it reduces the reaction cost, has fewer processes, simple processes, stable operation, and can achieve safe, fast, efficient and stable treatment effects.

[0055] 3. The present invention has a wide range of applications, does not require complex detection equipment, does not cause test and environmental pollution, can accurately predict the catalytic degradation characteristics of organic pollutants, and provides a scientific basis for the implementation of organic pollutant emissions and ecological risk assessment. It has the advantages of large prediction flux, low investment, low cost, and high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0057] Figure 1 This is a scanning electron microscope image of the model catalyst iron-cobalt composite oxide FCO prepared in Example 1 of the present invention;

[0058] Figure 2 The elemental spectrum of the model catalyst iron-cobalt composite oxide FCO prepared in Example 1 of the present invention;

[0059] Figure 3 This is a graph showing the degradation effect of the model catalyst iron-cobalt composite oxide FCO prepared in Example 1 of the present invention on different organic micropollutants;

[0060] Figure 4 This is a diagram showing the quenching effect of the model catalyst iron-cobalt composite oxide FCO prepared in Example 1 of the present invention in the FCO / PMS system;

[0061] Figure 5 The half-wave potential of the model catalyst iron-cobalt composite oxide FCO prepared in Example 1 of the present invention for degrading twelve pollutants Calculated value;

[0062] Figure 6 The various pollutants in the model catalyst iron-cobalt composite oxide FCO after degradation prepared in Example 1 of the present invention are Value and K obs the relationship between;

[0063] Figure 7 The peak potential and half-peak potential in the CV curve of crystalline amoxicillin (AMX) were obtained by using an electrochemical workstation for the model catalyst iron-cobalt composite oxide FCO prepared in Example 1 of the present invention.

[0064] Figure 8 The peak potential and half-peak potential in the CV curve of cephalexin hydrate (CFX) were obtained by using an electrochemical workstation for the model catalyst iron-cobalt composite oxide FCO prepared in Example 1 of the present invention.

[0065] Fig. 9 The peak potential and half-peak potential in the CV curve of ciprofloxacin (CIP) were obtained by using an electrochemical workstation for the model catalyst iron-cobalt composite oxide FCO prepared in Example 1 of the present invention.

[0066] Fig.10The peak potential and half-peak potential in the CV curve of levofloxacin (LFX) were obtained by using an electrochemical workstation for the model catalyst iron-cobalt composite oxide FCO prepared in Example 1 of the present invention.

[0067] Fig.11 The peak potential and half-peak potential in the CV curve of 4-acetamidophenol (ACP) were obtained by an electrochemical workstation for the model catalyst iron-cobalt composite oxide FCO prepared in Example 1 of the present invention.

[0068] Fig.12 The peak potential and half-peak potential in the CV curve of carbamazepine (CBZ) were obtained by an electrochemical workstation using the model catalyst iron-cobalt composite oxide FCO prepared in Example 1 of the present invention.

[0069] Fig.13 The peak potential and half-peak potential in the CV curve of metronidazole (MNZ) were obtained by using an electrochemical workstation for the model catalyst iron-cobalt composite oxide FCO prepared in Example 1 of the present invention.

[0070] Fig.14 The peak potential and half-peak potential in the CV curve of sulfamethoxazole (SMZ) were obtained by an electrochemical workstation for the model catalyst iron-cobalt composite oxide FCO prepared in Example 1 of the present invention.

[0071] Fig.15 The peak potential and half-peak potential in the CV curve of bisphenol A (BPA) were obtained by using an electrochemical workstation for the model catalyst iron-cobalt composite oxide FCO prepared in Example 1 of the present invention.

[0072] Fig.16 The peak potential and half-peak potential in the CV curve of benzoic acid (BA) were obtained by an electrochemical workstation using the model catalyst iron-cobalt composite oxide FCO prepared in Example 1 of the present invention.

[0073] Fig.17 The peak potential and half-peak potential in the CV curve of sulfadiazine (SDZ) were obtained by using an electrochemical workstation for the model catalyst iron-cobalt composite oxide FCO prepared in Example 1 of the present invention.

[0074] Fig.18 The peak potential and half-peak potential in the CV curve of naproxen (NPX) were obtained by using an electrochemical workstation for the model catalyst iron-cobalt composite oxide FCO prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0075] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention. The process parameters of the following embodiments that do not specify specific conditions are usually based on conventional conditions.

[0076] The endpoints and any values ​​of the ranges disclosed in the present invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in the present invention.

[0077] According to a first aspect of the present invention, there is provided a method for rapidly predicting the catalytic degradation rate of organic pollutants in a peroxymonosulfate non-radical degradation system, comprising the following steps:

[0078] S1: Activate peroxymonosulfate with a model catalyst to construct a FCO / PMS catalytic oxidation system;

[0079] S2: testing cyclic voltammetry curves of different organic pollutants in the FCO / PMS catalytic oxidation system;

[0080] S3: Calculate the half-wave potential of different organic pollutants based on the cyclic voltammetry curves of different organic pollutants tested;

[0081] S4: Calculating the degradation rate constants of different organic pollutants based on the half-wave potentials of the different organic pollutants.

[0082] Specifically, the selective oxidation catalyst iron-cobalt composite oxide described in the present invention can give full play to the high activation effect of the catalyst, accelerate the reaction process, and avoid the transportation of high-risk oxidants such as hydrogen peroxide. Compared with conventional perovskite catalysts, ozone advanced oxidation, electrocatalysis, photocatalysis and other methods, it reduces the reaction cost, has fewer processes, simple processes, stable operation, and can achieve safe, fast, efficient and stable treatment effects.

[0083] As an optional embodiment of the present invention, in step S4, the model equation for calculating the degradation rate constants of different organic pollutants is:

[0084]

[0085] Among them, K obsis the degradation rate constant; is the half-wave potential;

[0086] The R of the model equation 2 =0.697.

[0087] Specifically, cyclic voltammetry (CV) curves can be used to identify the redox potential of pollutants, and the half-wave potential of different pollutants It can be calculated from the redox peak in the cyclic voltammetry curve of the pollutant, which can represent the redox properties of the pollutant. According to the model equation of the degradation rate constants of different organic pollutants provided by the present invention, it can be found that the degradation rate constants K of different organic substances obs With half-wave potential Negatively correlated.

[0088] As an optional embodiment of the present invention, in step S1, the model catalyst is an iron-cobalt composite oxide FCO.

[0089] As an optional embodiment of the present invention, the preparation method of the model catalyst comprises the following steps:

[0090] (1) dissolving an iron salt and a cobalt salt in an alkaline solvent, and stirring at room temperature until a dark brown turbidity appears to obtain a mixture;

[0091] (2) transferring the mixture into a polytetrafluoroethylene reactor and performing a hydrothermal reaction at 390-470 K for 4-8 h;

[0092] Preferably, the hydrothermal reaction is carried out at 433 K for 6 h;

[0093] (3) After cooling to room temperature, the obtained solid was washed with ethanol and ultrapure water for multiple times, and dried at 350-400 K for 4-8 h to obtain a model catalyst;

[0094] Preferably, drying is carried out at 378 K for 6 h.

[0095] Specifically, the cobalt salts and iron salts used in the present invention are abundant in reserves and low in price. The preparation method of the present invention can simply and efficiently prepare the above-mentioned iron-cobalt-based catalyst. The prepared material has excellent catalytic performance, good stability and excellent anti-interference ability.

[0096] As an optional embodiment of the present invention, the molar ratio of the iron salt to the cobalt salt is (0-4): (0-4) (such as 4:1, 2:1, 1:1, 1:2, 1:4, iron salt alone, cobalt salt alone, etc.), wherein the iron salt and the cobalt salt are not zero at the same time;

[0097] And / or, the iron salt is one of ferric nitrate, ferric chloride or ferric acetylacetonate;

[0098] And / or, the cobalt salt is one of cobalt nitrate, cobalt chloride or cobalt acetylacetonate;

[0099] And / or, the alkaline solvent is 2-6 mol of one of sodium hydroxide, potassium hydroxide, calcium hydroxide or ammonia solution;

[0100] And / or, the stirring is ultrasonic and glass rod mixed stirring;

[0101] Preferably, the stirring conditions are: temperature of 20-40°C, preferably 25°C, and stirring time of 30-60 min.

[0102] As an optional embodiment of the present invention, in step S1, constructing the FCO / PMS catalytic oxidation system comprises the following steps:

[0103] S11: placing different organic pollutants in a container, stirring, and adjusting the pH to obtain an initial solution;

[0104] S12: placing the FCO catalyst in the initial solution, adjusting the pH of the water, stirring, and then adding sulfate to perform a catalytic oxidation reaction to obtain a FCO / PMS catalytic oxidation system.

[0105] Specifically, in step S12, the organic pollutant solution containing the FCO catalyst is stirred until it reaches an adsorption-desorption equilibrium, so that the pollutants are uniformly adsorbed on the catalyst, and the stirring is stopped.

[0106] As an optional implementation of the present invention, in step S11,

[0107] The stirring conditions are: temperature of 20-30°C, stirring time of 10-20min;

[0108] and / or, adjusting the pH of the water body using 1 mol / L H2SO4 solution and 1 mol / L NaOH solution;

[0109] Preferably, the pH is 3-11;

[0110] and / or, the organic contaminants include one or more of crystalline amoxicillin (AMX), cephalexin hydrate (CFX), ciprofloxacin (CIP), levofloxacin (LFX), 4-acetamidephenol (ACP), carbamazepine (CBZ), metronidazole (MNZ), sulfamethoxazole (SMZ), bisphenol A (BPA), benzoic acid (BA), sulfadiazine (SDZ), and naproxen (NPX);

[0111] And / or, the concentration of the organic pollutants is 1-7 mg / L, preferably 3-5 mg / L.

[0112] As an optional embodiment of the present invention, in step S12,

[0113] The stirring conditions are: stirring time is 5-15min, temperature is 20-30°C;

[0114] and / or, pH 3-11;

[0115] And / or, in step S12, the sulfate is potassium permonosulfate PMS;

[0116] Preferably, the concentration of the potassium permonosulfate PMS is 0.01 mmol-0.02 mmol.

[0117] Specifically, the sulfate is potassium peroxymonosulfate (PMS). Its structure is asymmetric and can be easily activated to produce non-radicals. Peroxymonosulfate achieves degradation through a non-radical pathway, which has the following advantages: (1) non-radical systems are generally not easily affected by coexisting components; (2) non-radical oxidation exhibits high selectivity in degrading organic pollutants; (3) non-radical systems have a high oxidant utilization efficiency; and (4) non-radical processes do not form toxic halogen byproducts.

[0118] As an optional embodiment of the present invention, in step S2, testing the cyclic voltammetry curves of different organic pollutants includes:

[0119] When the reaction time is 1 min, 2 min, 3 min, 4 min, 5 min, 7 min, and 10 min, the catalytic oxidation reaction liquid obtained in step S12 is sucked out through the filter membrane and quenched; the quenched reaction liquid is used to test the cyclic voltammetry curves of different organic pollutants;

[0120] and / or, the quenching agent comprises one or more of methanol (MeOH), tert-butyl alcohol (TBA), p-benzoquinone (p-BQ) and furfuryl alcohol (FFA);

[0121] Preferably, the quenching agent is methanol;

[0122] Preferably, the amount of methanol is 0.3-0.7 mL;

[0123] Preferably, the amount of methanol used is 0.5 mL.

[0124] As an optional embodiment of the present invention, in step S3, the half-wave potential of different organic pollutants is calculated. The equation is:

[0125]

[0126] Among them, E P is the potential of the peak current of the cyclic voltammetry curve;

[0127] E P / 2 is the potential of the half-peak current of the cyclic voltammetry curve.

[0128] The present invention will be further described in detail below with reference to specific embodiments and comparative examples.

[0129] Example 1

[0130] This embodiment provides a method for preparing a selective oxidation catalyst iron-cobalt composite oxide FCO, which strengthens the oxidation of persulfate to reduce organic pollutants in water and has the characteristics of selective oxidation, showing high selective oxidation of organic pollutants in water.

[0131] (1) A method for preparing an iron-cobalt composite oxide FCO comprises the following steps:

[0132] 3 mmol of ferric nitrate and 3 mmol of cobalt nitrate were dissolved in 30 mL of sodium hydroxide, and fully stirred and ultrasonically mixed at 25°C until a dark brown turbidity appeared; the mixture was then transferred to a polytetrafluoroethylene reactor and subjected to a hydrothermal reaction at 433 K for 6 h; after cooling to room temperature, the obtained solid was washed with ethanol and ultrapure water several times, and dried at 378 K for 6 h to obtain an iron-cobalt composite oxide, named FCO.

[0133] like Figure 1 The figure shows a scanning electron microscope image of the model catalyst iron-cobalt composite oxide FCO prepared in the present invention. Two different attachment conditions appear on the surface of FCO at the same time: a large number of irregular particles and a relatively rough surface are present, and there are also smooth, regular and relatively dispersed micro-crystalline flake surfaces. Its relatively loose structure avoids self-aggregation between particles and exposes more reactive surfaces.

[0134] like Figure 2 The elemental spectrum of the model catalyst iron-cobalt composite oxide FCO prepared in the present invention is shown in FIG. The elemental surface scanning diagram also shows the uniform distribution and simultaneous existence of all elements Fe, Co and O on the surface of FCO.

[0135] (2) crystalline amoxicillin (AMX), cephalexin hydrate (CFX), ciprofloxacin (CIP), levofloxacin (LFX), 4-acetamidephenol (ACP), carbamazepine (CBZ), metronidazole (MNZ), sulfamethoxazole (SMZ), bisphenol A (BPA), benzoic acid (BA), sulfadiazine (SDZ), and naproxen (NPX) of organic pollutants with a concentration of 5 mg / L were placed in a 100 mL beaker, the pH was adjusted to 8, and the temperature was stirred at 25°C for 20 min to obtain an initial solution;

[0136] (3) placing the obtained iron-cobalt composite oxide FCO in the initial solution, adjusting the pH to 8 with 1 mol / L H2SO4 solution and 1 mol / L NaOH solution, stirring at 25°C for 15 min until adsorption-desorption equilibrium is reached, and then stopping stirring.

[0137] (4) 0.01 mmol of persulfate was added to the initial solution containing the iron-cobalt composite oxide FCO to initiate the catalytic oxidation reaction. At regular intervals (1 min, 2 min, 3 min, 4 min, 5 min, 7 min, 10 min), the organic pollutants were filtered out. The specific steps were as follows: 1 mL of the reaction solution was aspirated by membrane under magnetic stirring at room temperature in a 250 mL beaker containing the organic pollutant solution, and the oxidation was immediately terminated with 0.5 mL of methanol.

[0138] Figure 4 The figure is a diagram showing the quenching effect of the model catalyst iron-cobalt composite oxide prepared in the present invention in the FCO / PMS system. A series of quenching experiments were conducted. Generally speaking, methanol (MeOH) is considered to be the main source of sulfate radicals (SO4 - , k = 9.7 × 108 M -1 s -1 ) and hydroxyl radicals (·OH, k = 9.7 × 108 M -1 s -1 ) scavengers, tert-butyl alcohol (TBA), p-benzoquinone (p-BQ) and furfuryl alcohol (FFA) can quench ·OH (k = 3.8-7.6×108M -1 s -1 ), superoxide radicals (O2 ·- , k = 9.8 × 108 M -1 s -1 ) and singlet oxygen ( 1 O2, k = 1.2 × 108M -1 s -1 ). In the FCO / PMS / SMZ system, when MeoH, TBA, and p-BQ were present, the SMZ degradation efficiency did not decrease significantly. However, when FFA was present, the degradation of SMZ showed a significant inhibitory effect, indicating that 1 O2 is the main form and plays a leading role, which further confirms that the catalytic oxidation system in this model system is not dominated by free radicals.

[0139] (5) The absorbed reaction solution was tested using an electrochemical workstation (CHI700E, China); wherein the conditions of the electrochemical workstation were:

[0140] Cyclic voltammetry (CV) tests were carried out between -1 V and +2.2 V at a scan rate of 20 mV s-1. The experiments were conducted in 20 mM phosphate buffer solution and 10 mg / L of the pollutant, using a three-electrode cell configuration, including a working electrode (glassy carbon electrode), a counter electrode (platinum electrode), and a reference electrode (saturated silver chloride electrode).

[0141] The results are as Figure 7-Figure 18 shown, and the peak potential and half-peak potential in the CV curve of each pollutant were obtained. The half-wave potential of each pollutant was calculated using the formula where E p and E p / 2 are the peak potential and half-peak potential (the potential of the peak current in the cyclic voltammetry curve), respectively.

[0142] (6) Based on the cyclic voltammetry curves of different organic pollutants tested, the half-wave potentials of different organic pollutants were calculated.

[0143] Figure 5 The calculated values of the half-wave potentials of twelve pollutants degraded by the model catalyst iron cobalt composite oxide FCO prepared in the present invention are shown. Figure 5 The relationship between these pollutants is shown as follows: ACP < BPA < NPX < LFX < SMZ < AMX < CBZ < CIP < CEX < SDZ < BA < MNZ. Research shows that by measuring the voltammetry curves of different pollutants, it is found that in the FCO / PMS catalytic oxidation system, the degradation rate constant K obs of different pollutants is related to the cyclic voltammetry curve (CV) and the half-wave potential . The cyclic voltammetry curve (CV) can be used to identify the redox potential of pollutants, and the half-wave potential of different pollutants can be calculated from the redox peaks in the cyclic voltammetry curve of the pollutants, which can represent the redox properties of the pollutants.

[0144] (7) Based on the half-wave potentials of the different organic pollutants, the degradation rate constants of different organic pollutants were calculated.

[0145] Figure 3 The degradation effect diagrams of the model catalyst iron cobalt composite oxide FCO prepared in the present invention on different organic micro-pollutants are shown. Different organic pollutants such as AMX, CFX, CIP, LFX, SDZ, SMZ, ACP, BA, BPA, CBZ, MNZ, and NPX were selected as target pollutants to further evaluate the catalytic oxidation performance system of FCO / PMS. As Figure 3As shown, the degradation effects of several organic pollutants can be clearly observed. ACP, BPA, AMX, and CFX were quickly removed within 10 minutes, while the degradation rates of NPX, LFX, and SMZ were slightly slower, all of which were completed within 10 minutes. In the FCO / PMS system, the degradation of SDZ, CBZ, and CIP was relatively gentle, with Kobs of 0.119-0.138min-1, and the removal rates of MNZ and BA were less than about 20%. The above results reveal the oxidation selectivity of the FCO / PMS system for various organic pollutants.

[0146] Figure 6 The various pollutants in the model catalyst iron-cobalt composite oxide FCO after degradation prepared in Example 1 of the present invention are Value and K obs As shown in the figure, in a system containing FCO and PMS, the 10 pollutants (ACP, BPA, NPX, LFX, SMZ, AMX, CBZ, CIP, CEX and SDZ) The value (below 1.2V) is significantly correlated with its lnKobs value. The difficulty of oxidizing pollutants increases with the increase of oxidation potential, while the The value of lnK increases significantly, while ob The s value is very low, far beyond the range of the degradation rate fitting line of the reaction between FCO and PMS. For pollutants with high redox potential, their removal depends more on the free radical pathway, which further confirms that the non-free radical pathway is dominant in the FCO / PMS system. obs From the relationship between the value and the half-wave potential, the pollutants except BA and MNZ show a good fitting trend, which is attributed to the selective oxidation of electron-rich pollutants by non-radical active species because The electron transfer pathway can only degrade electron-rich pollutants, so pollutants with relatively low redox potentials are more likely to lose electrons and be oxidized through non-radical pathways. Pollutants with high values ​​are more easily degraded by free radicals. Therefore, within a certain range, the degradation rate constant K of different organic matter obs With half-wave potential Negatively correlated, the model equation is Where R 2 =0.697.

[0147] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for rapidly predicting the catalytic degradation rate of organic pollutants in a peroxymonosulfate non-radical degradation system, characterized in that: The steps include: S1: Activate peroxymonosulfate with a model catalyst to construct a FCO / PMS catalytic oxidation system; The model catalyst is an iron-cobalt composite oxide FCO; The construction of the FCO / PMS catalytic oxidation system includes the following steps: S11: placing different organic pollutants in a container, stirring, and adjusting the pH to obtain an initial solution; S12: placing the FCO catalyst in the initial solution, adjusting the pH of the water, stirring, and then adding sulfate to perform a catalytic oxidation reaction to obtain a FCO / PMS catalytic oxidation system; S2: testing cyclic voltammetry curves of different organic pollutants in the FCO / PMS catalytic oxidation system; S3: Calculate the half-wave potential of different organic pollutants based on the cyclic voltammetry curves of different organic pollutants tested; Calculation of the half-wave potential of different organic pollutants The equation is: Among them, E P E is the potential of the peak current of the cyclic voltammetry curve; P / 2 is the potential of the half-peak current of the cyclic voltammetry curve; S4: calculating the degradation rate constants of different organic pollutants based on the half-wave potentials of the different organic pollutants; The model equation for calculating the degradation rate constants of different organic pollutants is: Among them, K obs is the degradation rate constant; is the half-wave potential; The R of the model equation 2 =0.

697.

2. The method for rapidly predicting the catalytic degradation rate of organic pollutants in a peroxymonosulfate non-radical degradation system according to claim 1, characterized in that: The preparation method of the model catalyst comprises the following steps: (1) dissolving an iron salt and a cobalt salt in an alkaline solvent, and stirring at room temperature until a dark brown turbidity appears to obtain a mixture; (2) transferring the mixture into a polytetrafluoroethylene reactor and performing a hydrothermal reaction at 390-470 K for 4-8 h; (3) After cooling to room temperature, the obtained solid was washed with ethanol and ultrapure water for multiple times, and dried at 350-400 K for 4-8 h to obtain a model catalyst.

3. The method for rapidly predicting the catalytic degradation rate of organic pollutants in a peroxymonosulfate non-radical degradation system according to claim 2, characterized in that: In step (2), a hydrothermal reaction is carried out at 433 K for 6 h.

4. The method for rapidly predicting the catalytic degradation rate of organic pollutants in a peroxymonosulfate non-radical degradation system according to claim 2, characterized in that: In step (3), drying is performed at 378 K for 6 h.

5. The method for rapidly predicting the catalytic degradation rate of organic pollutants in a peroxymonosulfate non-radical degradation system according to claim 2, characterized in that: The molar ratio of the iron salt to the cobalt salt is (0-4):(0-4), wherein the iron salt and the cobalt salt are not zero at the same time; And / or, the iron salt is one of ferric nitrate, ferric chloride or ferric acetylacetonate; And / or, the cobalt salt is one of cobalt nitrate, cobalt chloride or cobalt acetylacetonate; And / or, the alkaline solvent is 2-6 mol of one of sodium hydroxide, potassium hydroxide, calcium hydroxide or ammonia solution; And / or, in step (1), the stirring is ultrasonic and glass rod mixed stirring; In step (1), the stirring conditions are: temperature is 20-40° C., and stirring time is 30-60 min.

6. The method for rapidly predicting the catalytic degradation rate of organic pollutants in a peroxymonosulfate non-radical degradation system according to claim 2, characterized in that: In step (1), the stirring temperature is 25°C.

7. The method for rapidly predicting the catalytic degradation rate of organic pollutants in a peroxymonosulfate non-radical degradation system according to claim 1, characterized in that: In step S11, The stirring conditions are: temperature of 20-30°C, stirring time of 10-20min; and / or, using 1 mol / L H2SO4 solution and 1 mol / L NaOH solution to adjust the pH of the water body; and / or, the organic contaminants include one or more of crystalline amoxicillin, cephalexin hydrate, ciprofloxacin, levofloxacin, 4-acetamidephenol, carbamazepine, metronidazole, sulfamethoxazole, bisphenol, benzoic acid, sulfadiazine, and naproxen; And / or, the concentration of the organic pollutants is 1-7 mg / L.

8. The method for rapidly predicting the catalytic degradation rate of organic pollutants in a peroxymonosulfate non-radical degradation system according to claim 1, characterized in that: In step S11, the pH is adjusted to 3-11.

9. The method for rapidly predicting the catalytic degradation rate of organic pollutants in a peroxymonosulfate non-radical degradation system according to claim 1, characterized in that: The concentration of the organic pollutants is 3-5 mg / L.

10. The method for rapidly predicting the catalytic degradation rate of organic pollutants in a peroxymonosulfate non-radical degradation system according to claim 1, characterized in that: In step S12, The stirring conditions are: stirring time is 5-15min, temperature is 20-30°C; and / or, pH 3-11; And / or, in step S12, the sulfate is potassium permonosulfate PMS; The concentration of the potassium permonosulfate PMS is 0.01 mmol-0.02 mmol.

11. The method for rapidly predicting the catalytic degradation rate of organic pollutants in a peroxymonosulfate non-radical degradation system according to claim 1, characterized in that: In step S2, testing cyclic voltammetry curves of different organic pollutants includes: When the reaction time is 1 min, 2 min, 3 min, 4 min, 5 min, 7 min and 10 min respectively, the catalytic oxidation reaction liquid obtained in step S12 is sucked out through the filter membrane and quenched; the quenched reaction liquid is used to test the cyclic voltammetry curves of different organic pollutants.

12. The method for rapidly predicting the catalytic degradation rate of organic pollutants in a peroxymonosulfate non-radical degradation system according to claim 11, characterized in that: The quenching agent used for quenching includes one or more of methanol, tert-butyl alcohol, p-benzoquinone and furfuryl alcohol.

13. The method for rapidly predicting the catalytic degradation rate of organic pollutants in a peroxymonosulfate non-radical degradation system according to claim 12, characterized in that: The quenching agent used was methanol.

14. The method for rapidly predicting the catalytic degradation rate of organic pollutants in a peroxymonosulfate non-radical degradation system according to claim 13, characterized in that: The amount of methanol used is 0.3-0.7mL.

15. The method for rapidly predicting the catalytic degradation rate of organic pollutants in a peroxymonosulfate non-radical degradation system according to claim 14, characterized in that: The amount of methanol used was 0.5 mL.

Images