A method for treating organic wastewater based on the combined application of tetravalent iron process and ozone and its application

Abstract

The invention discloses a method for treating organic sewage based on a tetravalent iron process and an ozone combined application and an application thereof, the method comprising: adjusting the pH value of target organic sewage to a first pH value; sequentially adding a pre-prepared target ozone solution, a target sodium persulfate solution, and a target ferrous iron solution to the target organic sewage for reaction to obtain a first phase solution; taking out a sewage sample of a target preset volume from the first phase solution, analyzing the concentration of various organic pollutants in each sewage sample; adjusting the pH value of the first state sewage to a second pH value; adding a target disinfectant to the first phase solution, and reacting under dark reaction conditions to obtain a second phase solution; enriching the disinfection byproducts corresponding to the second phase solution, and quantitatively analyzing the concentration of the disinfection byproducts after enrichment. The present invention can achieve efficient removal of refractory organic pollutants while effectively reducing the generation of disinfection byproducts.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to an organic sewage treatment method based on the combined application of a tetravalent iron process and ozone and its application. Background Art

[0002] With the acceleration of industrialization and urbanization, water pollution is becoming increasingly serious, especially in urban sewage, which contains a large number of organic pollutants. Emerging pollutants such as pharmaceuticals and personal care products (PPCPs) are typical examples of these organic pollutants, which are usually difficult to remove through traditional water treatment methods. During the chlorination disinfection process after water treatment, disinfectants react with dissolved organic matter (DOM) in water to produce disinfection by-products (DBPs). Disinfection by-products such as trichloromethanes (THMs) and haloacetic acids (HAAs) not only have a negative impact on water quality, but may also pose a potential threat to human health, thus bringing greater challenges to the water treatment process.

[0003] As an emerging advanced oxidation process, ferric iron (Fe(IV)-AOPs) has been widely used in water treatment in recent years. Fe(IV)-AOPs introduce iron ions (Fe(II)) to react with oxidants to generate ferric iron and reactive free radicals, effectively degrading organic pollutants in water with good selectivity. Currently, common ferric iron treatment processes include ferrous iron / sodium peroxydisulfate (Fe(II) / PDS), ferrous iron / hypochlorous acid (Fe(II) / HClO), and ferrous iron / sodium peroxymonosulfate (Fe(II) / PMS). These technologies can effectively generate ferric iron, degrade organic pollutants in water, restructure dissolved organic matter, and reduce the formation of disinfection byproducts. However, single Fe(IV)-AOPs technology still has certain limitations in practical applications, especially when treating complex water quality. Treatment effects are poor or higher reagent dosages may be required to degrade target pollutants, leading to increased costs and the potential for the formation of some disinfection byproducts.

[0004] The ferrous iron / peroxydisulfate (Fe(II) / PDS) process can effectively simplify the molecular structure of complex organic compounds and reduce the formation of chlorination disinfection byproducts, but it is less effective in degrading pharmaceutical organic compounds. Therefore, in practice, higher dosages may be required to degrade organic pollutants. This not only increases operating costs but can also lead to excessive iron ions in the water, potentially causing heavy metal pollution.

[0005] Among them, in the ferrous iron / hypochlorous acid process (Fe(II) / HClO), hypochlorous acid easily decomposes in water and is extremely unstable. Although hypochlorous acid has strong disinfection and pollutant degradation capabilities, it easily generates a large number of chlorinated disinfection byproducts such as chloroacetic acid and chloroform due to the addition of chlorine in water treatment. These byproducts not only affect water quality but also pose potential hazards to human health, limiting its applicability in certain applications.

[0006] The ferrous iron / permonosulfate (Fe(II) / PMS) process is highly sensitive to water pH and the presence of other ions or organic matter. Even slight fluctuations in water quality can significantly reduce oxidation efficiency, thereby reducing the degradation of organic pollutants and increasing uncertainty and operational difficulty in practical applications. Furthermore, due to the process's stringent reaction conditions and high oxidant consumption, the economic feasibility of large-scale water treatment applications is challenging. Summary of the Invention

[0007] In order to solve the technical problems in the prior art, the present invention provides an organic wastewater treatment method and application based on the combined application of tetravalent iron process and ozone, which can achieve efficient removal of difficult-to-degrade organic pollutants while effectively reducing the production of disinfection by-products. The overall process is economical, efficient and environmentally friendly, and is suitable for a variety of actual water treatment scenarios.

[0008] Specifically, the present invention includes the following contents.

[0009] The first aspect of the present invention provides a method for treating organic wastewater based on the combined application of a tetravalent iron process and ozone, comprising:

[0010] Step S1, adjusting the pH value of the target organic sewage to be treated to a first pH value; step S2, adding a pre-prepared target ozone solution, a target sodium persulfate solution and a target divalent iron solution to the target organic sewage after the pH value is adjusted to the first pH value in sequence for reaction to obtain a first-stage solution; step S3, taking out a target preset volume of sewage sample from the first-stage solution every first target preset time, and after a reaction time of a second target preset time, obtaining multiple sewage samples at different time points, and analyzing the concentration of various organic pollutants in each of the sewage samples; step S4, adjusting the pH value of the first-state sewage remaining after taking out multiple sewage samples to a second pH value, and the second pH value is greater than the first pH value; step S5, adding a target disinfectant to the first-stage solution after the pH value is adjusted to the second pH value, and reacting for a third target preset time under dark reaction conditions to obtain a second-stage solution; step S6, enriching the disinfection by-products corresponding to the second-stage solution, and quantitatively analyzing the concentration of the enriched disinfection by-products.

[0011] Preferably, the first pH value is in the range of 2.8-3.2, and the second pH value is in the range of 7.5-8.5.

[0012] Preferably, the first target preset time length is 1-1.2 minutes, the second target preset time length is 5-6 minutes, the third target preset time length is 2.5-3.5 days, and the target preset volume is 10-15 ml.

[0013] Preferably, in step 3, a liquid phase mass spectrometer is used to analyze the concentration of various organic pollutants in each of the sewage samples.

[0014] Preferably, in step 2, after the pre-prepared target ozone solution is added to the target organic wastewater, the ozone concentration of the target organic wastewater is 15-25 μmol / L.

[0015] Preferably, in step 2, after the pre-prepared target sodium persulfate solution is added to the target organic wastewater, the sodium persulfate concentration of the target organic wastewater is 180-220 μmol / L.

[0016] Preferably, in step 2, after the pre-prepared target divalent iron solution is added to the target organic wastewater, the divalent iron concentration of the target organic wastewater is 180-220 μmol / L.

[0017] Preferably, the target disinfectant is monochloramine disinfectant, and after the monochloramine disinfectant is added, the monochloramine disinfectant concentration of the first-stage solution is 3-7 mg / LC 12.

[0018] Preferably, in step S6, the disinfection by-products corresponding to the second-stage solution are enriched, and the concentration of the enriched disinfection by-products is quantitatively analyzed, including: collecting 40-50 mL of the second-stage solution, enriching all the disinfection by-products of the second-stage solution by liquid-liquid extraction, and quantitatively analyzing the concentration of all the disinfection by-products using a triple quadrupole gas mass spectrometer.

[0019] The second aspect of the present invention provides an application of the organic wastewater treatment method based on the combined application of the tetravalent iron process and ozone according to any one of the above items in the field of organic wastewater treatment.

[0020] The technical effects of the present invention include but are not limited to:

[0021] The present invention aims to overcome the challenges faced by existing technologies in treating complex water quality, such as high cost, low reaction efficiency, poor degradation of pharmaceutical organic pollutants, and the generation of by-products. By generating tetravalent iron in ozone-containing water, the synergistic effect of Fe(II) / PDS and trace ozone is fully utilized. The main advantages are reflected in the following aspects:

[0022] (1) The oxidative degradation ability of refractory organic matter is significantly enhanced. The introduction of trace ozone plays a key role in enhancing oxidation in the Fe(II) / PDS system, which can deeply degrade stubborn organic pollutants such as pharmaceuticals and personal care products (PPCPs) in water bodies, greatly improving the overall treatment effect.

[0023] (2) Reduce the formation of disinfection by-products. The synergistic oxidation effect can effectively modify the molecular structure of dissolved organic matter (DOM), and then significantly reduce the amount of disinfection by-products formed during the subsequent chlorination disinfection process, thereby ensuring water quality safety.

[0024] (3) Reduce the dosage and processing cost. Since the addition of trace ozone can improve the oxidation efficiency of tetravalent iron, this process does not need to increase the dosage of reagents such as sodium persulfate or iron ions. At the same time, low-concentration ozone is easy to synthesize and store, and will not affect human health, thereby effectively controlling the operating cost and reflecting obvious economic advantages.

[0025] (4) Wide applicability: The present invention exhibits high degradation efficiency and good water quality safety under diverse water quality conditions such as urban sewage and industrial pharmaceutical wastewater, showing broad application potential and providing a new technical path for achieving sustainable utilization of water resources.

[0026] In summary, through the above-mentioned synergistic effect, the present invention can achieve efficient removal of difficult-to-degrade organic pollutants, while effectively reducing the production of disinfection by-products. The overall process is economical, efficient, and environmentally friendly, and is suitable for a variety of actual water treatment scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the degradation efficiency [concentration] / [concentration]0 of sulfamethoxazole after treating the sewage containing the antibiotic-sulfamethoxazole in Example 1 using the ferrous iron / sodium peroxydisulfate process (Fe(II) / PDS), ferrous iron / hypochlorous acid (Fe(II) / HCl O), ferrous iron / sodium peroxymonosulfate process (Fe(II) / PMS) and the composite tetravalent iron water treatment process technology based on the combined application of Fe(II) / PDS and trace ozone of the present invention.

[0028] Figure 2 Schematic diagram of the concentration of disinfection by-products after three days of chlorination disinfection of the sewage in Example 1 using the ferrous iron / sodium peroxydisulfate (Fe(II) / PDS), ferrous iron / hypochlorous acid (Fe(II) / HCl O), ferrous iron / sodium peroxymonosulfate process (Fe(II) / PMS) and the composite tetravalent iron water treatment process technology based on the combined application of Fe(II) / PDS and trace ozone of the present invention.

[0029] Figure 3 Schematic diagram of the degradation efficiency [concentration] / [concentration]0 of trimethoprim after treating the sewage containing the antibiotic-resistant trimethoprim in Example 2 using the ferrous iron / sodium peroxydisulfate process (Fe(II) / PDS), ferrous iron / hypochlorous acid (Fe(II) / HCl O), ferrous iron / sodium peroxymonosulfate process (Fe(II) / PMS) and the composite tetravalent iron water treatment process technology based on the combined application of Fe(II) / PDS and trace ozone of the present invention.

[0030] Figure 4 Schematic diagram of the concentration of disinfection by-products after three days of chlorination disinfection of the sewage in Example 2 using the ferrous iron / sodium peroxydisulfate (Fe(II) / PDS), ferrous iron / hypochlorous acid (Fe(II) / HCl O), ferrous iron / sodium peroxymonosulfate process (Fe(II) / PMS) and the composite tetravalent iron water treatment process technology based on the combined application of Fe(II) / PDS and trace ozone of the present invention.

[0031] Figure 5Schematic diagram of the degradation efficiency of diclofenac [concentration] / [concentration]0 after treating the wastewater containing the non-steroidal anti-inflammatory drug - diclofenac in Example 3 using the ferrous iron / sodium peroxydisulfate process (Fe(II) / PDS), ferrous iron / hypochlorous acid (Fe(II) / HClO), ferrous iron / sodium peroxymonosulfate process (Fe(II) / PMS) and the composite tetravalent iron water treatment process technology based on the combined application of Fe(II) / PDS and trace ozone provided in the embodiments of the present invention.

[0032] Figure 6 Schematic diagram of the concentration of disinfection by-products after three days of chlorination disinfection of the sewage in Example 3 using the ferrous iron / sodium peroxydisulfate (Fe(II) / PDS), ferrous iron / hypochlorous acid (Fe(II) / HCl O), ferrous iron / sodium peroxymonosulfate process (Fe(II) / PMS) and the composite tetravalent iron water treatment process technology based on the combined application of Fe(II) / PDS and trace ozone provided in the embodiments of the present invention. DETAILED DESCRIPTION

[0033] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0034] It should be understood that the terms described in the present invention are only for describing particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges in the present invention, it should be understood that the upper and lower limits of the ranges and each intermediate value therebetween are specifically disclosed. Each smaller range between any stated value or intermediate value within a stated range and any other stated value or intermediate value within the stated range is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0035] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention pertains. Although preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related thereto. In the event of any conflict with any incorporated document, the present specification shall prevail. Unless otherwise specified, "%" refers to percentages based on weight.

[0036] Those skilled in the art should understand that other steps or operations may be included before or after the steps of this embodiment, or between any steps, for example, to further optimize and / or improve the method described in the present invention.

[0037] Example 1

[0038] This embodiment uses the technical solution of the present invention to treat and detect organic wastewater containing the antibiotic sulfamethoxazole, and the steps are as follows:

[0039] (1) Acquisition of actual water samples: Water samples were collected from a sewage treatment plant in Shanghai.

[0040] (2) Filter and collect water samples to remove obvious solid suspended impurities.

[0041] (3) Liquid chromatography-mass spectrometry was used to quantify the initial concentration of sulfamethoxazole.

[0042] (4) Preparation of ferrous iron stock solution and sodium persulfate stock solution:

[0043] Ferrous perchlorate (Fe(CI O4)2·6H2O) was dissolved in 0.01 mol / L perchloric acid to prepare an Fe(II) stock solution. Its concentration was standardized and quantified using the 1,10-phenanthroline method, with a target concentration of 100 mmol / L. Sodium peroxydisulfate was dissolved in 500 mL of ultrapure water to prepare a 100 mmol / L stock solution. Both the ferrous and sodium peroxydisulfate stock solutions were stored in a refrigerator at 4°C to prevent degradation.

[0044] (5) Preparation of ozone stock solution:

[0045] Ozone-enriched water was prepared by introducing oxygen into 4°C ultrapure water through an ozone generator. Ozone concentration was standardized using UV absorbance measurement (ε260 = 3200 M-1 cm-1) to prepare a 100 μmol / L ozone stock solution for immediate use.

[0046] (6) Preparation of disinfectant:

[0047] Prepare a 20 mM monochloramine stock solution by reacting sodium hypochlorite and ammonium chloride in a 1:1.2 molar ratio at pH 8.0. Quantify the disinfectant concentration by measuring absorbance at 245 nm and 295 nm using a spectrophotometer. Prepare the solution for immediate use.

[0048] (7) Carry out the processing of the technical solution of the present invention and detect relevant data:

[0049] In 500mL of water, pre-adjust the pH to 3 (the range can be 2.8-3.2. Adjusting the pH value is necessary for the tetravalent iron process reaction and can increase the formation and oxidation capacity of tetravalent iron). Add 20μmol / L (the range can be 15-25μmol / L) of trace ozone. Then, add 5mg / L of dissolved organic matter, 20μmol / L of target organic pollutants, 200μmol / L (the range can be 180-220μmol / L) of sodium persulfate oxidant, and 200μmol / L (the range can be 180-220μmol / L) of divalent iron stock solution. React for a certain time. According to the reaction time of 0s, 1min, 2min, 3min, 4min, and 5min, collect 10mL samples at each time, and analyze the concentration of target organic pollutants using liquid chromatography-mass spectrometry. The pH is then adjusted to 8 (a range of 7.5-8.5 is available. pH adjustment is intended to facilitate the addition of the disinfectant, increasing its disinfecting power and reaction time, as disinfectants are more stable and less susceptible to self-degradation at a pH of 8). A disinfectant containing 5 mg / LC l² (a range of 3-7 mg / LC l²) of monochloramine is added, and the reaction is carried out in the dark for three days (a range of 2.5-3.5 is available) to simulate an urban pipeline environment. After three days, a 40 mL sample is collected and enriched for disinfection byproducts (DBPs) using liquid-liquid extraction. The concentrations of five common DBPs are then quantitatively analyzed using a triple quadrupole gas chromatography-mass spectrometer. The liquid-liquid extraction procedure involves mixing the sample to be tested with an organic solvent (methyl tert-butyl ether) containing an internal standard. The sample is then stirred and shaken vigorously to promote the transfer of DBPs from the aqueous phase to the organic phase. After standing and separating, the organic and aqueous phases are separated, and the DBPs are extracted into the upper organic phase. Finally, the sample is enriched and concentrated using pure nitrogen purging to obtain the final sample to be tested.

[0050] Among them, the disinfection by-product analysis steps are: analyze the sample to be tested using a triple quadrupole gas mass spectrometer to obtain the peak time and peak area of ​​the disinfection by-product and the internal standard substance, obtain the ratio based on the peak areas of the two, and substitute the ratio into the standard curve to obtain the quantitative concentration of the disinfection by-product.

[0051] In addition, control experiments were conducted using three common ferric iron treatment processes in water without ozone under the same experimental conditions to calculate target pollutant concentrations and disinfection byproduct concentrations. All experiments were repeated three times to verify the stability and reliability of the experimental results, reduce accidental errors, and ensure the accuracy and credibility of the data.

[0052] The experimental results are as follows Figure 1 and 2As shown, the target pollutant [concentration] / [concentration]0 measured using three common tetravalent iron treatment processes Fe(II) / PDS, Fe(II) / HClO, Fe(II) / PMS and the technical solution of this study (i.e., a composite tetravalent iron water treatment process using Fe(II) / PDS in combination with trace ozone) was 0.38, 0.15, 0.36 and 0.06; the concentrations of disinfection by-products after three days of chlorination were 37.44 μg / L, 53.76 μg / L, 41.58 μg / L and 34.60 μg / L, respectively.

[0053] Experimental result shows, three kinds of common tetravalent iron treatment processes have achieved certain treatment effect in terms of target pollutant removal and chlorination three days after disinfection by-product generation, but still have the disadvantage of not being thoroughly removed or the higher concentration of by-products.By contrast, the composite tetravalent iron water treatment process based on Fe (II) / PDS and micro-ozone combined application proposed by the present invention has shown higher efficiency ([concentration] / [concentration]0 is only 0.06) in terms of target pollutant removal, and its disinfection product concentration after three days of chlorination disinfection is also relatively lower (34.60 μ g / L), fully illustrating that the technical solution of the present invention can significantly improve the degradation efficiency of organic pollutant sulfamethoxazole and suppress the generation of disinfection by-products.This result highlights the comprehensive advantages of the technology of the present invention in terms of high efficiency and safety, and has good application prospects.

[0054] Example 2

[0055] This embodiment uses the technical solution of the present invention to process and detect organic wastewater containing the antibiotic trimethoprim, and the steps are as follows:

[0056] (1) Acquisition of actual water samples: Water samples were collected from a pharmaceutical company factory in Guangzhou.

[0057] (2) Filter and collect water samples to remove obvious solid suspended impurities.

[0058] (3) Quantify the initial trimethoprim concentration using liquid chromatography-mass spectrometry.

[0059] (4) Carry out the study according to steps (4), (5), (6) and (7) in Example 1.

[0060] The experimental results are as follows Figure 3 and 4As shown, the target pollutant [concentration] / [concentration]0 measured by three common tetravalent iron treatment processes Fe(II) / PDS, Fe(II) / HCl O, and Fe(II) / PMS and the technical solution of the present invention (i.e., a composite tetravalent iron water treatment process using Fe(II) / PDS in combination with trace ozone) is 0.34, 0.25, 0.26, and 0.11; the disinfection by-product concentrations after three days of chlorination are 41.27 μg / L, 59.74 μg / L, 43.06 μg / L, and 36.35 μg / L, respectively.

[0061] The experimental results show that the three common tetravalent iron treatment processes have certain effects on the removal of target pollutants and the disinfection by-products produced by chlorination in the subsequent three days, but they still face limitations in degradation efficiency and by-product control that are not ideal. In contrast, the present invention uses a composite tetravalent iron water treatment process that synergistically applies trace ozone and Fe (II) / PDS, which significantly reduces the [concentration] / [concentration] 0 (0.11) of the target pollutants, while controlling the concentration of disinfection by-products at 36.35 μg / L, which is better than other control groups. This shows that the synergistic effect of trace ozone and Fe (II) / PDS effectively suppresses the formation of disinfection by-products while efficiently degrading the organic pollutant trimethoprim, fully demonstrating the comprehensive advantages of the invention in water treatment efficiency and water quality safety.

[0062] Example 3

[0063] This example utilizes the technical solution of the present invention to treat and detect wastewater mainly containing diclofenac, a nonsteroidal anti-inflammatory drug, in the following steps:

[0064] (1) Acquisition of actual water samples: Water samples were collected from a pharmaceutical company’s factory in Shenzhen.

[0065] (2) Filter and collect water samples to remove obvious solid suspended impurities.

[0066] (3) Liquid chromatography-mass spectrometry was used to quantify the initial concentration of diclofenac.

[0067] (4) Carry out the study according to steps (4), (5), (6) and (7) in Example 1.

[0068] The experimental results are as follows Figure 5 and 6As shown, the target pollutant [concentration] / [concentration]0 measured by three common tetravalent iron treatment processes Fe(II) / PDS, Fe(II) / HCl O, and Fe(II) / PMS and the technical solution of the present invention (i.e., a composite tetravalent iron water treatment process using Fe(II) / PDS and trace ozone) is 0.26, 0.08, 0.33, and 0.05; the disinfection by-product concentrations after three days of chlorination are 28.47 μg / L, 41.53 μg / L, 30.81 μg / L, and 27.25 μg / L, respectively.

[0069] Experimental results show that traditional tetravalent iron treatment process (Fe (II) / PDS, Fe (II) / HCl O, Fe (II) / PMS) has various degrees of deficiency in the control of target pollutant removal and subsequent chlorination by-products. In contrast, the present invention uses a composite tetravalent iron water treatment process in which trace ozone and Fe (II) / PDS are used in collaboration. While significantly reducing the relative concentration of target pollutants ([concentration] / [concentration] 0 is only 0.05), the disinfection by-product concentration after chlorination for three days is controlled at 27.25 μg / L, which is better than the control group. The result proves that the introduction of trace ozone can strengthen the oxidative degradation ability of Fe (II) / PDS, and effectively suppresses the formation of disinfection by-products, further highlighting the comprehensive advantages of the present invention in terms of water treatment efficiency and water quality safety.

[0070] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. Various modifications and variations may be made to the exemplary embodiments of the present specification without departing from the scope or spirit of the present invention. The scope of the claims is to be given the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A method for treating organic wastewater based on the combined application of tetravalent iron process and ozone, characterized in that: include: Step S1, adjusting the pH value of the target organic wastewater to be treated to a first pH value; Step S2, adding a pre-prepared target ozone solution, a target sodium persulfate solution, and a target divalent iron solution to the target organic wastewater after the pH value is adjusted to the first pH value in sequence to react to obtain a first-stage solution; Step S3, extracting a target preset volume of sewage sample from the first stage solution at a first target preset time interval, reacting for a second target preset time interval, obtaining multiple sewage samples at different time points, and analyzing the concentration of various organic pollutants in each of the sewage samples; Step S4, adjusting the pH value of the first-state sewage remaining after taking out the plurality of sewage samples to a second pH value, wherein the second pH value is greater than the first pH value; Step S5, adding a target disinfectant to the sewage in the first state after the pH value is adjusted to the second pH value, and performing a reaction under dark reaction conditions for a third target preset time to obtain a second-stage solution; Step S6, enriching the disinfection byproducts corresponding to the second stage solution, and quantitatively analyzing the concentration of the enriched disinfection byproducts; Wherein, the first pH value ranges from 2.8 to 3.2, and the second pH value ranges from 7.5 to 8.5; Wherein, in step S2, after the pre-prepared target ozone solution is added to the target organic wastewater, the ozone concentration of the target organic wastewater is 15-25 μmol / L; Wherein, in step S2, after the pre-prepared target sodium persulfate solution is added to the target organic wastewater, the sodium persulfate concentration of the target organic wastewater is 180-220 μmol / L; Wherein, in step S2, after the pre-prepared target divalent iron solution is added to the target organic wastewater, the divalent iron concentration of the target organic wastewater is 180-220 μmol / L.

2. The organic wastewater treatment method based on the combined application of tetravalent iron process and ozone according to claim 1, characterized in that, The first target preset time is 1-1.2 min, the second target preset time is 5-6 min, the third target preset time is 2.5-3.5 d, and the target preset volume is 10-15 ml.

3. The organic wastewater treatment method based on the combined application of tetravalent iron process and ozone according to claim 1 is characterized in that, In step S3, the concentration of various organic pollutants in each of the sewage samples is analyzed using a liquid phase mass spectrometer.

4. The organic wastewater treatment method based on the combined application of tetravalent iron process and ozone according to claim 1, characterized in that, The target disinfectant is monochloramine disinfectant, and after the monochloramine disinfectant is added, the monochloramine disinfectant concentration of the first-state sewage is 3-7 mg / LCl2.

5. The organic wastewater treatment method based on the combined application of tetravalent iron process and ozone according to claim 4 is characterized in that, In step S6, the disinfection by-products corresponding to the second-stage solution are enriched, and the concentration of the enriched disinfection by-products is quantitatively analyzed, including: 40-50 mL of the second-stage solution was collected, all the disinfection by-products in the second-stage solution were enriched by liquid-liquid extraction, and the concentrations of all the disinfection by-products were quantitatively analyzed using a triple quadrupole gas mass spectrometer.

6. Application of the organic wastewater treatment method based on the combined application of tetravalent iron process and ozone according to any one of claims 1 to 5 in the field of organic wastewater treatment.

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