Process for purifying hexazinone production wastewater
By modifying the enamel-lined reactor and graphite condenser into microfiltration and oxidation towers, and combining pretreatment, catalytic oxidation, and biological denitrification processes, the problem of purifying and reducing the amount of wastewater from cycloazinone production was solved, achieving efficient wastewater treatment and resource utilization.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ANHUI GUANGXIN CHENGCHEN TECHNOLOGY CO LTD
- Filing Date
- 2026-03-30
- Publication Date
- 2026-05-19
AI Technical Summary
The high ammonia nitrogen and COD wastewater generated during the existing cycloazinone production process is difficult to purify to meet standards. Traditional wastewater treatment methods are inefficient, consume large amounts of reagents, and have poor waste reduction effects, which cannot meet the environmental protection requirements of industrial-scale cycloazinone production.
The existing enamel-lined reactor was transformed into an enamel-lined microfiltration reactor, and the graphite condenser was transformed into a graphite condensing oxidation tower. Combining pretreatment, catalytic oxidation, and biological denitrification processes, composite catalysts and microbial agents were used to achieve deep purification of wastewater. Part of the purified wastewater was then reused in the production process, and the system was designed as an integrated reuse system.
It achieves deep purification of high ammonia nitrogen and COD wastewater, reduces the amount of wastewater discharged by ≥80%, reduces the material-to-water ratio to 1:0.8, and reduces treatment costs through raw material reuse, which meets the development requirements of green chemical industry and circular economy.
Smart Images
Figure SMS_1
Abstract
Description
Technical Field
[0001] This invention relates to the field of wastewater treatment technology, specifically to a purification process for wastewater from the production of cycloazinone. Background Technology
[0002] Cycloazine, a highly efficient and low-toxicity triazine herbicide, is the preferred agent for controlling bamboo, trees, and shrubs, and is widely used in afforestation, forest firebreak maintenance, and other fields. Its traditional synthesis process uses cyclohexyl isocyanate, monomethylamine, sodium thiocyanate, and other raw materials, generating large amounts of high-ammonia-nitrogen and high-COD wastewater. Ammonia nitrogen and COD levels far exceed national emission standards, placing significant pressure on environmental treatment. Furthermore, traditional wastewater treatment processes are mostly end-of-pipe treatments, resulting in low treatment efficiency, high pesticide consumption, and poor wastewater reduction, making them unsuitable for the environmental requirements of industrial-scale cycloazine production.
[0003] Current methods for reducing wastewater in cycloazinone production only involve adjusting the raw materials and equipment, but this is insufficient to achieve adequate wastewater purification. Therefore, there is an urgent need for a wastewater purification process adapted to the characteristics of cycloazinone production to improve the depth of purification of cycloazinone production wastewater and solve the pollution problem at its source. Summary of the Invention
[0004] The present invention aims to solve the problem that existing cycloazinone production processes are unable to achieve wastewater purification standards.
[0005] To address the above problems, this invention provides a purification process for wastewater from the production of cycloazinone, comprising the following steps: Step 1: Pass the wastewater from the cycloazinone production process into an enamel microfiltration reactor, control the temperature at 30℃~40℃ and the filtration pressure at 0.1MPa~0.2MPa, and filter out the pretreated wastewater; Step 2: Pump the pretreated wastewater into a graphite condenser oxidation tower, add a composite catalyst composed of sodium methoxide methanol solution and methyl chloroformate to react, control the temperature at 60℃~70℃ and the reaction time at 1h~2h to obtain the oxygenated wastewater. Step 3: Adjust the pH of the wastewater after oxygenation to 7.0-7.5, and introduce it into a biological denitrification reactor. Add a compound inoculant of nitrifying and denitrifying bacteria to react. Control the temperature at 25℃-30℃ and the dissolved oxygen at 2mg / L-3mg / L. React for 3-4 hours to obtain purified wastewater. Step 4: 80% of the purified wastewater is recycled to the raw material preparation process for the production of cycloazinone, and the remaining 20% is discharged after passing the test. The enamel-lined microfiltration reactor and the graphite condenser oxidation tower were modified from the existing enamel-lined reactor and graphite condenser in the cycloazinone production process, respectively.
[0006] The purification process for cycloazinone production wastewater of the present invention has, but is not limited to, the following beneficial effects compared with the prior art: This invention transforms existing enamel-lined reactors and graphite condensers used in cycloazinone production into wastewater treatment equipment, achieving integrated reuse of production and wastewater treatment equipment without the need for new large-scale non-standard equipment, significantly reducing equipment investment. The design incorporates a staged process of pretreatment, catalytic oxidation, biological denitrification, and greywater reuse, achieving deep purification of high-ammonia nitrogen and COD wastewater. Furthermore, by reusing 80% of the greywater, wastewater volume is reduced from the production source, lowering the feed-to-water ratio to 1:0.8 and reducing external wastewater discharge by ≥80%. Simultaneously, the raw materials for cycloazinone production are reused as catalysts for wastewater treatment, achieving not only material sharing but also improved catalytic oxidation effects. This solves the technical challenge of simultaneously achieving wastewater purification and reduction in existing technologies. The process steps are tightly integrated, adapting to the continuous production requirements of cycloazinone industrialization, with no secondary pollution, meeting the requirements of green chemical development.
[0007] Preferably, in step 1, the method for converting the enamel-lined reactor into an enamel-lined microfiltration reactor is as follows: a microporous enamel-lined filter membrane with a pore size of 0.01 μm to 0.1 μm is added inside the reactor of the enamel-lined reactor.
[0008] Specifically, the microporous enamel filter membrane is highly compatible with the enamel-lined reactor, and will not produce leaching substances that cause secondary pollution. Moreover, the pore size of 0.01um to 0.1um can accurately intercept suspended residues and unreacted raw material particles in wastewater, resulting in stable pretreatment effects. The modification method is simple, requiring only the addition of a filter membrane without the need for large-scale dismantling of the original reactor. The modification can be completed without interrupting production, making industrial implementation easy. After modification, the equipment has both microfiltration and reaction functions, improving equipment utilization.
[0009] Preferably, in step 1, the suspended particulate matter removal rate of the pretreated wastewater filtered by the enamel microfiltration reactor is ≥95%.
[0010] Specifically, a suspended particulate matter removal rate of ≥95% can effectively remove solid impurities from wastewater, preventing suspended particles from entering subsequent catalytic oxidation and biological denitrification processes, preventing blockage of the packing material in the oxidation tower, and preventing the biological denitrification agent from being encapsulated by solid particles and becoming inactive, thus ensuring the reaction efficiency and stability of subsequent processes. At the same time, a high removal rate can reduce organic suspended pollutants in wastewater, reduce the load on subsequent COD degradation, and improve the overall purification efficiency of the process.
[0011] Preferably, in step 2, the method for converting the graphite condenser into a graphite condensing oxidation tower is as follows: an oxidation reaction chamber is connected in series on one side of the condensation chamber in the graphite condenser, so that the condensate in the condensation chamber continuously flows back to the oxidation reaction chamber.
[0012] Specifically, the design of the series oxidation reaction chamber makes full use of the existing cavity structure of the graphite condenser, which is easy to modify; the graphite material has strong corrosion resistance, which is suitable for the reaction environment of the catalytic oxidation process, and the condensate continuously flows back to the oxidation reaction chamber, which can realize the internal circulation of process water without the need for additional process water replenishment, further reducing the amount of production wastewater; at the same time, the condensation effect of the condensation chamber can remove the heat generated by the catalytic oxidation reaction in time, avoid the reaction system temperature from being too high and causing catalyst deactivation, and ensure the stable progress of the catalytic oxidation reaction.
[0013] Preferably, in step 2, the mass ratio of sodium methoxide methanol solution to methyl chloroformate in the composite catalyst is 1:(30-40).
[0014] Specifically, a mass ratio of 1:(30-40) maximizes the synergistic effect of the alkaline catalytic action of sodium methoxide methanol solution and the oxidation action of methyl chloroformate. This effectively activates the organic COD components in the wastewater and achieves efficient oxidative degradation, resulting in a stable reduction of the COD content in the wastewater to <500mg / L after catalytic oxidation. This ratio range is suitable for the component characteristics of cycloazinone production wastewater, avoiding the problems of excessively high catalyst ratio leading to reagent waste and excessively low ratio leading to poor degradation effect, thus controlling treatment costs while ensuring purification effect.
[0015] Preferably, in step 2, both the sodium methoxide methanol solution and methyl chloroformate in the composite catalyst are raw materials directly used in the production process of cycloazinone.
[0016] Specifically, this operation enables the reuse of raw materials for cycloazinone production and wastewater treatment agents, eliminating the need for additional procurement of specialized chemical catalysts and significantly reducing the procurement costs of wastewater treatment agents. Simultaneously, the raw materials used are all conventionally used in cycloazinone production, and process personnel are familiar with their properties and operating methods, eliminating the need for additional operational training and reducing labor costs for process implementation. The design of raw material reuse allows for seamless integration of the wastewater treatment process and the cycloazinone production process, enabling direct use of raw materials from the production tank as catalysts, simplifying the process operation flow.
[0017] Preferably, in step 2, the COD content of the oxygenated wastewater is reduced to < 500 mg / L.
[0018] Specifically, effluent with COD < 500 mg / L can significantly reduce the organic load of subsequent biological denitrification processes, avoid the inhibitory effect of high COD on nitrifying and denitrifying bacteria, and ensure the metabolic activity of biological denitrification agents. At the same time, this indicator provides suitable water quality conditions for the biological denitrification process, enabling the biological denitrification reaction to proceed efficiently, and ultimately achieving the standard requirement of ammonia nitrogen content < 15 mg / L in purified wastewater, thus realizing the synergistic effect of each process.
[0019] Preferably, in step 3, the ratio of viable bacteria in the mixture of nitrifying bacteria and denitrifying bacteria is 2:1.
[0020] Specifically, the 2:1 live bacteria ratio balances the ammonia nitrification by nitrifying bacteria with the nitrate denitrification by denitrifying bacteria. The rate at which nitrifying bacteria convert ammonia nitrogen to nitrate nitrogen matches the rate at which denitrifying bacteria convert nitrate nitrogen to N2, preventing the accumulation of nitrate nitrogen in the system and achieving efficient ammonia nitrogen removal. This keeps the ammonia nitrogen content in the purified wastewater stably reduced to <15 mg / L. This ratio of bacterial agent is suitable for the wastewater quality after catalytic oxidation, with high bacterial agent survival rate and fast reaction rate, shortening the reaction time of biological denitrification.
[0021] Preferably, in step 3, the ammonia nitrogen content of the purified wastewater is <15 mg / L.
[0022] Specifically, the ammonia nitrogen content is <15mg / L, which fully meets the national industrial wastewater discharge standards, solving the technical problems of excessive ammonia nitrogen content and high environmental protection pressure in the traditional cycloazinone production wastewater. The wastewater that meets the standards can be directly discharged in part, and the recycled water has a low ammonia nitrogen content, which will not have an adverse effect on the preparation of raw materials and synthesis reaction of cycloazinone production, thus ensuring the production quality of cycloazinone products.
[0023] Preferably, in step 3, the microbial sludge generated during the purification wastewater generation process is dewatered by pressure filtration and then reused as a raw material for organic fertilizer.
[0024] Specifically, microbial sludge, after being dewatered by filter press, contains abundant organic matter and nitrogen, which can be directly used as raw material for organic fertilizer, thus improving the economic efficiency of the process. At the same time, the resource utilization of sludge avoids the solid waste treatment costs and environmental problems caused by traditional sludge landfill and incineration, realizing the three-in-one approach of waste reduction, purification and resource utilization in the treatment of cycloazinone production wastewater, which is in line with the concept of circular economy development. Detailed Implementation
[0025] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.
[0026] The terminology used in the embodiments of this application is for the purpose of describing particular implementations only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the implementations of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.
[0027] It should be understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the implementation regulations of this application.
[0028] The weights of the relevant components mentioned in the embodiments of this application can refer not only to the specific content of each component, but also to the proportional relationship between the weights of the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this application is within the scope disclosed in the embodiments of this application. Specifically, the mass described in the embodiments of this application can be a mass unit known in the chemical industry, such as μg, mg, g, or kg.
[0029] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.
[0030] Unless otherwise specified, all raw materials, reagents, instruments, and equipment used in this application can be purchased commercially or prepared using existing methods. For example, the sources and types of raw materials involved in the following examples and comparative examples are as follows: Sodium methoxide methanol solution: industrial grade, 30% by mass, a special raw material for the production of cycloazinone, purchased from Shandong Banghua Oil & Chemical Co., Ltd. Methyl chloroformate: Industrial grade, 99.5% purity, a special raw material for the production of cycloazinone, purchased from Jiangsu Zhengdan Chemical Industry Co., Ltd. Nitrifying bacteria: Industrial grade, viable count ≥10¹ 0 CFU / g, purchased from Beijing Bio-Bio Biotechnology Co., Ltd. Denitrifying bacteria: Industrial grade, viable count ≥10¹ 0 CFU / g, purchased from Beijing Bio-Bio Biotechnology Co., Ltd. Dilute hydrochloric acid: analytical grade, 1 mol / L, purchased from Sinopharm Chemical Reagent Co., Ltd. Sodium hydroxide solution: analytical grade, 1 mol / L, purchased from Sinopharm Chemical Reagent Co., Ltd. Ferrous sulfate: industrial grade, 99% purity, purchased from Sinopharm Chemical Reagent Co., Ltd.; Hydrogen peroxide: industrial grade, 30% by mass, purchased from Sinopharm Chemical Reagent Co., Ltd. Enameled microfiltration reactor: It is obtained by modifying the existing enamel-lined reactor in the cycloazinone production process, and adding a microporous enamel-lined filter membrane with a pore size of 0.01um to 0.1um inside the reactor of the enamel-lined reactor; Graphite condensing oxidation tower: It is modified from the existing graphite condenser in the cycloazinone production process. An oxidation reaction chamber is connected in series on one side of the condensation chamber in the graphite condenser, so that the condensate in the condensation chamber continuously flows back to the oxidation reaction chamber.
[0031] Example 1
[0032] This embodiment discloses a purification process for wastewater from the production of cycloazinone, comprising the following steps: Step 1: The wastewater from the production of cycloazinone was passed into an enamel-lined microfiltration reactor, with the temperature controlled at 35℃ and the filtration pressure at 0.15MPa. Microfiltration removed suspended residues, yielding pretreated wastewater. Testing showed that the removal rate of suspended particulate matter in the pretreated wastewater was 98%. Step 2: The pretreated wastewater is pumped into a graphite condenser oxidation tower, and a composite catalyst consisting of sodium methoxide methanol solution and methyl chloroformate in a mass ratio of 1:35 is added to react. The temperature is controlled at 65℃ and the reaction time is 1.5h to obtain the catalytically treated wastewater. After testing, the COD content of the catalytically treated wastewater is reduced to 450mg / L. Step 3: Adjust the pH of the oxygenated wastewater to 7.2 using 1 mol / L dilute hydrochloric acid and 1 mol / L sodium hydroxide solution, then pass it into a biological denitrification reactor. Add a bacterial agent containing nitrifying and denitrifying bacteria at a live bacteria ratio of 2:1 to carry out the reaction. Control the temperature at 28℃ and dissolved oxygen at 2.5 mg / L, and react for 3.5 hours to obtain purified wastewater. After testing, the ammonia nitrogen content in the purified wastewater was reduced to 12 mg / L. Step 4: 80% of the purified wastewater is recycled to the raw material preparation process for the production of cycloazinone, and the remaining 20% is discharged after passing the test.
[0033] Example 2
[0034] Compared with Example 1, the only difference is that in step 2, the composite catalyst composed of sodium methoxide methanol solution and methyl chloroformate in a mass ratio of 1:35 is replaced with a composite catalyst composed of sodium methoxide methanol solution and methyl chloroformate in a mass ratio of 1:30; the other steps and conditions remain exactly the same.
[0035] Example 3
[0036] Compared with Example 1, the only difference is that in step 2, the composite catalyst composed of sodium methoxide methanol solution and methyl chloroformate in a mass ratio of 1:35 is replaced with a composite catalyst composed of sodium methoxide methanol solution and methyl chloroformate in a mass ratio of 1:40; the other steps and conditions remain exactly the same.
[0037] Example 4
[0038] The only difference compared to Example 1 is: (1) In step 1, the control temperature is reduced from 35℃ to 30℃ and the filtration pressure is reduced from 0.15MPa to 0.1MPa; (2) In step 2, the controlled temperature is reduced from 65℃ to 60℃ and the reaction time is reduced from 1.5h to 1h; (3) In step 3, the controlled temperature is reduced from 28°C to 25°C and the dissolved oxygen is reduced from 2.5 mg / L to 2 mg / L; The other steps and conditions remain exactly the same.
[0039] Example 5
[0040] The only difference compared to Example 1 is: (1) In step 1, the control temperature is increased from 35℃ to 40℃ and the filtration pressure is increased from 0.15MPa to 0.2MPa; (2) In step 2, the controlled temperature is increased from 65℃ to 70℃ and the reaction time is increased from 1.5h to 2h; (3) In step 3, the controlled temperature is increased from 28℃ to 30℃ and the dissolved oxygen is increased from 2.5mg / L to 3mg / L; The other steps and conditions remain exactly the same.
[0041] Comparative Example 1
[0042] The pH of the cycloazinone production wastewater was adjusted to 7.2 using 1 mol / L dilute hydrochloric acid and 1 mol / L sodium hydroxide solution. The wastewater was then introduced into a biological denitrification reactor. A bacterial agent containing nitrifying and denitrifying bacteria in a 2:1 ratio of live bacteria was added to carry out the reaction. The temperature was controlled at 28℃ and the dissolved oxygen at 2.5 mg / L. The reaction was carried out for 3.5 hours to obtain purified wastewater.
[0043] Comparative Example 2
[0044] Compared with Example 1, the only difference is that in step 2, the composite catalyst composed of sodium methoxide methanol solution and methyl chloroformate in a mass ratio of 1:35 is replaced with a composite catalyst composed of ferrous sulfate and hydrogen peroxide in a mass ratio of 1:40; the other steps and conditions remain exactly the same.
[0045] The treatment effects of the purification processes for the cycloazinone production wastewater in Examples 1-5 and Comparative Examples 1-2 were tested. The specific test items and methods are as follows: Pretreatment suspended particulate matter removal rate: The suspended solids content in the wastewater before and after treatment was determined by gravimetric method according to the "Determination of Suspended Solids in Water - Gravimetric Method" (GB11901-1989), and the removal rate was calculated. COD content of wastewater after catalytic oxidation: determined by potassium dichromate method according to "Determination of Chemical Oxygen Demand in Water - Potassium Dichromate Method" (GB 11914-1989); Ammonia nitrogen content in purified wastewater: determined by Nessler's reagent spectrophotometry, according to the "Determination of Ammonia Nitrogen in Water - Nessler's Reagent Spectrophotometry" (HJ 535-2009); Production material-to-water ratio: Calculate the actual material-to-water ratio after water reuse by statistically analyzing the mass ratio of total raw material input to total fresh water consumption during the production of cycloazinone. Wastewater discharge reduction rate: The wastewater discharge of the traditional process and the wastewater discharge of this process are statistically compared, and the reduction rate is calculated using the formula "(wastewater discharge of the traditional process - wastewater discharge of this process) / wastewater discharge of the traditional process × 100%".
[0046] The test results are listed in Table 1, as follows: Table 1
[0047] Analyzing the data in Table 1, we can see that... 1. In Examples 1-5, the pretreatment suspended particulate matter removal rate was ≥95%, the COD content of the wastewater after oxygenation was <500mg / L, the ammonia nitrogen content of the purified wastewater was <15mg / L, the production material-to-water ratio was consistently reduced to 1:0.8, and the wastewater discharge reduction rate was ≥80%. These results fully verify that the purification process of the present invention can achieve the dual effects of wastewater purification meeting standards and wastewater reduction, and the process has strong stability.
[0048] 2. Comparative Example 1 is a traditional single biological denitrification process without pretreatment and catalytic oxidation steps. The results show that the ammonia nitrogen content of the treated wastewater is as high as 85 mg / L, far exceeding the national discharge standard of 15 mg / L, and there is no reclaimed water reuse. The feed-to-water ratio is only 1:5.2, and the amount of wastewater discharged is not reduced. This comparative result proves that the pretreatment, catalytic oxidation, and biological denitrification staged process designed in this invention is a necessary condition for achieving the purification of high ammonia nitrogen COD wastewater from cycloazinone: pretreatment can remove suspended particles and reduce the load on subsequent processes; catalytic oxidation can efficiently degrade COD and avoid high concentrations of organic matter inhibiting the activity of bacterial agents; staged synergistic treatment is necessary to achieve deep purification, while single biological treatment cannot cope with the high pollution characteristics of cycloazinone wastewater.
[0049] 3. Comparative Example 2 used a catalyst that was not recycled from raw materials. The results showed that the COD content after oxidation was 510 mg / L (slightly exceeding 500 mg / L), the ammonia nitrogen content was 15 mg / L (the critical value for compliance), the production feed-to-water ratio was only 1:2.0, and the wastewater discharge reduction rate was only 40%, far lower than that of Examples 1-5. This comparative result proves that the combined design of raw material reuse and wastewater recycling in this invention is the core key to achieving efficient wastewater purification and significant wastewater reduction: the catalyst compounded with cycloazinone production raw materials has a better oxidation effect than wastewater characteristics, and 80% wastewater recycling reduces fresh water consumption and wastewater discharge from the source.
[0050] In summary, the purification process of this invention can simultaneously achieve purification compliance and significant volume reduction, solving two major core problems of existing technologies. At the same time, the reuse of raw materials and equipment significantly reduces processing costs, and the resource utilization of solid waste further improves the economic benefits of the process. It produces no secondary pollution, meets the development requirements of green chemical industry and circular economy, and has extremely high industrial application value.
[0051] The foregoing has described several embodiments of the present invention in detail, but these descriptions are merely preferred embodiments and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.
Claims
1. A purification process for wastewater from the production of cycloazinone, characterized in that, Includes the following steps: Step 1: Pass the wastewater from the cycloazinone production process into an enamel microfiltration reactor, control the temperature at 30℃~40℃ and the filtration pressure at 0.1MPa~0.2MPa, and filter out the pretreated wastewater; Step 2: Pump the pretreated wastewater into a graphite condenser oxidation tower, add a composite catalyst composed of sodium methoxide methanol solution and methyl chloroformate to react, control the temperature at 60℃~70℃ and the reaction time at 1h~2h to obtain the oxygenated wastewater. Step 3: Adjust the pH of the wastewater after oxygenation to 7.0-7.5, and introduce it into a biological denitrification reactor. Add a compound inoculant of nitrifying and denitrifying bacteria to react. Control the temperature at 25℃-30℃ and the dissolved oxygen at 2mg / L-3mg / L. React for 3-4 hours to obtain purified wastewater. Step 4: 80% of the purified wastewater is recycled to the raw material preparation process for the production of cycloazinone, and the remaining 20% is discharged after passing the test. The enamel-lined microfiltration reactor and the graphite condenser oxidation tower were modified from the existing enamel-lined reactor and graphite condenser in the cycloazinone production process, respectively.
2. The purification process for cycloazinone production wastewater according to claim 1, characterized in that, In step 1, the method for converting the enamel-lined reactor into an enamel-lined microfiltration reactor is as follows: a microporous enamel-lined filter membrane with a pore size of 0.01 μm to 0.1 μm is added inside the reactor of the enamel-lined reactor.
3. The purification process for cycloazinone production wastewater according to claim 1, characterized in that, In step 1, the suspended particulate matter removal rate of the pretreated wastewater filtered through the enamel microfiltration reactor is ≥95%.
4. The purification process for cycloazinone production wastewater according to claim 1, characterized in that, In step 2, the method for transforming the graphite condenser into a graphite condensing oxidation tower is as follows: an oxidation reaction chamber is connected in series on one side of the condensation chamber in the graphite condenser, so that the condensate in the condensation chamber continuously flows back to the oxidation reaction chamber.
5. The purification process for cycloazinone production wastewater according to claim 1, characterized in that, In step 2, the mass ratio of sodium methoxide methanol solution to methyl chloroformate in the composite catalyst is 1:(30-40).
6. The purification process for cycloazinone production wastewater according to claim 1, characterized in that, In step 2, both the sodium methoxide methanol solution and methyl chloroformate in the composite catalyst are raw materials directly used in the cycloazinone production process.
7. The purification process for cycloazinone production wastewater according to claim 1, characterized in that, In step 2, the COD content of the oxygenated wastewater is reduced to < 500 mg / L.
8. The purification process for cycloazinone production wastewater according to claim 1, characterized in that, In step 3, the ratio of viable bacteria in the mixture of nitrifying bacteria and denitrifying bacteria is 2:
1.
9. The purification process for cycloazinone production wastewater according to claim 1, characterized in that, In step 3, the ammonia nitrogen content of the purified wastewater is <15mg / L.
10. The purification process for cycloazinone production wastewater according to claim 1, characterized in that, In step 3, the microbial sludge generated during the wastewater purification process is dewatered by pressure filtration and then reused as a raw material for organic fertilizer.