A method for treating organic waste water by wet oxidation

Abstract

The present disclosure relates to a method for treating organic wastewater by wet oxidation, which comprises: treating the organic wastewater by wet oxidation in the presence of a catalyst; the catalyst comprises a first catalyst and a second catalyst, the first catalyst comprises a soluble transition metal salt, and the second catalyst comprises a carrier and a rare earth metal supported on the carrier. The method of the present disclosure uses a mixed catalyst of a homogeneous transition metal salt and a heterogeneous carrier supporting a rare earth metal for treating organic wastewater by wet oxidation, and the transition metal in the first catalyst and the rare earth metal in the second catalyst have a synergistic effect, which can reduce the content of refractory organic matter in the organic wastewater, improve the biodegradability, and make the treated wastewater have a lower COD value and a higher B / C value, so that the wastewater can be directly discharged to a sewage treatment plant.

Description

Technical Field

[0001] This disclosure relates to a wastewater treatment method, specifically, a method for wet oxidation treatment of organic wastewater. Background Technology

[0002] Industrial production processes often generate wastewater with high concentrations of organic matter. This type of wastewater contains a high percentage of organic components and sometimes toxic or harmful substances, making it difficult to meet discharge requirements using simple biological treatment methods. Treating concentrated organic wastewater using methods such as combustion is not only energy-intensive and costly but also prone to causing secondary pollution. Wet oxidation, on the other hand, offers advantages such as high efficiency, energy saving, and stable operation, and has therefore gained widespread attention and popularity. Wet oxidation of high-concentration organic wastewater involves reacting it with air (or oxygen) at high temperature and pressure, causing the organic matter in the wastewater to be oxidized and decomposed into carbon dioxide and water.

[0003] CN1084496A discloses a wet oxidation purification catalyst for industrial wastewater containing high concentrations of organic matter and ammonia, and its preparation method. The catalyst is composed of a noble metal component (one of Pt, Pd, Ru, Ir, Rh) and rare earth elements supported on TiO2, wherein the weight content of the noble metal is 0.3%–1%. At a space velocity of 2 h⁻¹, the catalyst is prepared by... -1 Under these conditions, the COD removal rate can reach 98.5%, and the ammonia nitrogen removal rate can reach over 99.6%. Due to the high precious metal content, the catalyst has high manufacturing and processing costs. Summary of the Invention

[0004] The purpose of this disclosure is to provide a method for wet oxidation treatment of organic wastewater. This method uses a homogeneous transition metal salt and a heterogeneous rare earth metal-supported carrier as a mixed catalyst, which can reduce the content of organic matter in the organic wastewater, improve biodegradability, and give the treated wastewater a lower COD value and a higher B / C value.

[0005] To achieve the above objectives, this disclosure provides a method for wet oxidation treatment of organic wastewater, the method comprising: performing wet oxidation treatment on the organic wastewater in the presence of a catalyst; the catalyst comprising a first catalyst and a second catalyst, the first catalyst comprising a soluble transition metal salt, and the second catalyst comprising a support and a rare earth metal supported on the support.

[0006] Optionally, the method includes: mixing the concentrated organic wastewater and the ammonium oxime process wastewater to obtain mixed wastewater; adjusting the pH of the mixed wastewater to below 6; and performing the wet oxidation treatment.

[0007] Optionally, the soluble transition metal salt is selected from one or more of soluble iron salts, soluble cobalt salts, soluble nickel salts, and soluble platinum salts, preferably soluble iron salts, and more preferably ferrous sulfate; the content of soluble transition metal salts in the mixed wastewater is 100-12000 mg / L, preferably 500-11000 mg / L, and more preferably 3000-10000 mg / L.

[0008] Optionally, the carrier is selected from one or more of activated carbon, molecular sieve and activated coke, preferably activated carbon; the rare earth metal is selected from cerium and / or lanthanum, preferably cerium; and the content of the rare earth metal, calculated as metal element, is 0.2-5% by weight, preferably 0.3-4% by weight, based on the total weight of the carrier.

[0009] Optionally, the ratio of COD to the content of the detected substance calculated as H2O2 in the mixed wastewater is 1:(0.1-5), preferably 1:(0.3-2); the content of the detected substance calculated as H2O2 is 300-22000 mg / L, preferably 1000-20000 mg / L, more preferably 10000-18000 mg / L.

[0010] Optionally, the organic wastewater has a COD of 500–50000 mg / L, preferably 1000–30000 mg / L; a B / C ratio of 0–0.3, preferably 0–0.2; the ammonia oxime industrial wastewater has a COD of 300–30000 mg / L, preferably 500–15000 mg / L; the content of the detected substance calculated as H2O2 is 200–30000 mg / L, preferably 500–15000 mg / L; and a B / C ratio of 0–0.3, preferably 0–0.2.

[0011] Optionally, the method for preparing the concentrate includes: concentrating the ammonia oxime process wastewater using a vacuum distillation method or a membrane concentration method to obtain the concentrate and fresh water; preferably, the volume of the concentrate is 1 to 10% of the volume of the ammonia oxime process wastewater.

[0012] Optionally, the temperature of the vacuum distillation is 50–100°C, preferably 60–90°C; the time is 0.2–10 h, preferably 0.5–5 h; and the vacuum degree is 0.01–0.1 kPa, preferably 0.02–0.08 kPa.

[0013] Optionally, the conditions for the wet oxidation treatment include: a temperature of 80–400°C, preferably 100–300°C, more preferably 120–250°C; a pressure of 1.0–15 MPa, preferably 1.5–10 MPa, more preferably 2–7 MPa; the wet oxidation treatment is carried out in a reactor, which includes a fixed-bed reactor, a fluidized-bed reactor, or a batch reactor; preferably, the wet oxidation treatment is carried out in a fixed-bed reactor, and the volumetric liquid hourly space velocity (LHSV) of the reaction is 0.05–30 h⁻¹. -1 Preferably 0.2 to 10 hours -1 .

[0014] Optionally, the method further includes: introducing an oxidizing gas into the mixed wastewater, wherein the amount of oxidizing gas introduced is 1 to 3 times the amount of oxidant required to increase the COD value of the mixed wastewater, preferably 1.05 to 1.5 times; preferably, the oxidizing gas includes oxygen and / or air.

[0015] Through the above technical solution, this disclosure provides a method for wet oxidation treatment of organic wastewater. This method uses a homogeneous transition metal salt and a heterogeneous rare earth metal-supported carrier as a mixed catalyst. When used for wet oxidation treatment of organic wastewater, the transition metal in the first catalyst and the rare earth metal in the second catalyst have a synergistic effect, which can reduce the content of recalcitrant organic matter in the organic wastewater, improve biodegradability, and make the treated wastewater have a lower COD value and a higher B / C value, which can be directly discharged to the sewage treatment plant to achieve the purpose of treating waste with waste.

[0016] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Detailed Implementation

[0017] The following provides a detailed description of specific embodiments of this disclosure. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit this disclosure.

[0018] The first aspect of this disclosure provides a method for wet oxidation treatment of organic wastewater, the method comprising: performing wet oxidation treatment on the organic wastewater in the presence of a catalyst; the catalyst comprising a first catalyst and a second catalyst, the first catalyst comprising a soluble transition metal salt, and the second catalyst comprising a support and a rare earth metal supported on the support.

[0019] This disclosure provides a method for wet oxidation treatment of organic wastewater. The method uses a homogeneous transition metal salt and a heterogeneous rare earth metal-supported carrier as a mixed catalyst. When used for wet oxidation treatment of organic wastewater, the transition metal in the first catalyst and the rare earth metal in the second catalyst have a synergistic effect, which can reduce the content of recalcitrant organic matter in the organic wastewater, improve biodegradability, and make the treated wastewater have a lower COD value and a higher B / C value, which can be directly discharged to a sewage treatment plant.

[0020] In one embodiment of this disclosure, the method includes: mixing the concentrated organic wastewater and the ammonium oxime process wastewater to obtain mixed wastewater; adjusting the pH of the mixed wastewater to below 6; and performing the wet oxidation treatment. The inventors of this disclosure have discovered that when the concentrated organic wastewater and the ammonium oxime process wastewater are mixed and wet oxidation is performed in the presence of the aforementioned catalyst, the transition metal in the first catalyst and the rare earth metal in the second catalyst have a synergistic effect. This can promote the reaction between the H2O2-like substances detected in the concentrated wastewater and the organic matter in the organic wastewater, further reducing the content of recalcitrant organic matter in the organic wastewater, improving biodegradability, and resulting in treated wastewater with a lower COD value and a higher B / C ratio, which can be directly discharged to a wastewater treatment plant, achieving the goal of treating waste with waste.

[0021] In one embodiment of this disclosure, the soluble transition metal salt is selected from one or more of soluble iron salts, soluble cobalt salts, soluble nickel salts, and soluble platinum salts, preferably soluble iron salts, and more preferably ferrous sulfate; the content of the soluble transition metal salt in the mixed wastewater is 100–12000 mg / L, preferably 500–11000 mg / L, and more preferably 3000–10000 mg / L. In the above embodiment, by selecting a preferred homogeneous soluble transition metal salt as the first catalyst, it is beneficial to ensure uniform contact between the first catalyst and the mixed wastewater, thereby improving its catalytic effect.

[0022] In one embodiment of this disclosure, the carrier is selected from one or more of activated carbon, molecular sieves and activated coke, preferably activated carbon; the rare earth metal is selected from cerium and / or lanthanum, preferably cerium; based on the total weight of the carrier, the content of the rare earth metal, calculated as a metal element, is 0.2 to 5% by weight, preferably 0.3 to 4% by weight, more preferably 0.5 to 4% by weight.

[0023] In one embodiment of this disclosure, the ratio of COD to the content of the detected substance calculated as H2O2 in the mixed wastewater is 1:(0.1-5), preferably 1:(0.3-2); in a preferred embodiment, the content of the detected substance calculated as H2O2 in the mixed wastewater is 300-22000 mg / L, preferably 1000-20000 mg / L, more preferably 10000-18000 mg / L. The detected substance calculated as H2O2 refers to organic peroxides with H2O2 properties, and its content is detected using the method of GB1616-2003. In the above embodiments, by selecting the preferred mixed wastewater, it is beneficial for the organic matter in the mixed wastewater to fully contact with the organic peroxides, thereby improving the catalytic effect of the catalyst.

[0024] In one embodiment of this disclosure, the COD of the organic wastewater is 500–50000 mg / L, preferably 1000–30000 mg / L, more preferably 5000–30000 mg / L; the B / C ratio is 0–0.3, preferably 0–0.2; the COD of the ammonia oxime industrial wastewater is 300–30000 mg / L, preferably 500–15000 mg / L, more preferably 3000–13000 mg / L; the content of the detected substance calculated as H2O2 is 200–30000 mg / L, preferably 500–15000 mg / L, more preferably 3000–13000 mg / L; the B / C ratio is 0–0.3, preferably 0–0.2. Wherein, B / C is an abbreviation for the ratio of BOD to COD, indicating the biodegradability of the wastewater; when B / C > 0.3, the wastewater can be biodegraded. The organic wastewater disclosed herein contains a large number of recalcitrant organic macromolecules, and the ammonia oxime chemical industry wastewater contains a large number of organic peroxides with H2O2 properties. The COD values ​​of both types of wastewater are above 1000 mg / L, and they contain substances that are toxic and harmful to microorganisms. Their B / C ratio is close to 0, so they cannot be directly discharged into the sewage treatment system to avoid causing a large number of microorganisms to die.

[0025] In one embodiment of this disclosure, the method for preparing the concentrate includes: concentrating the ammonia oxime process wastewater using a vacuum distillation method or a membrane concentration method to obtain the concentrate and fresh water; in a preferred embodiment, the volume of the concentrate is 1-10% of the volume of the ammonia oxime process wastewater. In the above embodiment, by selecting the concentration method, it is beneficial to concentrate the H2O2-like substances detected in the ammonia oxime industrial wastewater into the concentrate, thereby increasing the B / C value of the concentrated fresh water and allowing it to be directly treated in the enterprise's existing wastewater treatment plant.

[0026] In one embodiment of this disclosure, the temperature of the vacuum distillation is 50–100°C, preferably 60–90°C; the time is 0.2–10 h, preferably 0.5–5 h; and the vacuum degree is 0.01–0.1 kPa, preferably 0.02–0.08 kPa.

[0027] In one embodiment of this disclosure, the wet oxidation treatment conditions include: a temperature of 80–400°C, preferably 100–300°C, more preferably 120–250°C; and a pressure of 1.0–15 MPa, preferably 1.5–10 MPa, more preferably 2–7 MPa. The wet oxidation treatment is carried out in a reactor, which includes a fixed-bed reactor, a fluidized-bed reactor, or a stirred tank reactor. In the above embodiment, the selected wet oxidation treatment is beneficial for reducing the COD value of wastewater, increasing the B / C ratio, and thus improving its biodegradability.

[0028] In a preferred embodiment, the wet oxidation treatment is carried out in a fixed-bed reactor, and the volumetric liquid hourly space velocity (LHSV) of the reaction is 0.05–30 h⁻¹. -1 Preferably 0.2 to 10 hours -1 In the above embodiments, the first catalyst and the second catalyst are in contact in a fixed-bed reactor and effectively work synergistically to reduce the content of recalcitrant organic matter in the wastewater and improve its biodegradability.

[0029] In one embodiment of this disclosure, the method further includes: introducing an oxidizing gas into the mixed wastewater, wherein the amount of oxidizing gas introduced is 1 to 3 times, preferably 1.05 to 1.5 times, the amount of oxidant required to increase the COD value of the mixed wastewater; preferably, the oxidizing gas includes oxygen and / or air.

[0030] The present disclosure is further described in detail below through examples. All raw materials used in the examples are commercially available. The BOD determination method is the five-day biochemical method (HJ 505-2009), and the COD determination method is the potassium dichromate method (GB 11914-89). B / C is the ratio of BOD to COD. The content of rare earth metals loaded on the carrier is tested using an XRF analyzer, model Rigaku 3271E.

[0031] Example 1

[0032] (1) The COD of the ammonia oxime industrial wastewater of a certain petrochemical plant is 3970 mg / L, the total phosphorus concentration is 115 mg / L, the concentration of the detected substance as H2O2 is 6120 mg / L, and the B / C ratio is 0.01. The ammonia oxime industrial wastewater is concentrated by vacuum distillation at a temperature of 80℃ for 2 hours and a vacuum degree of 0.08 kPa. A concentrate with a volume of 5% of the ammonia oxime process wastewater and fresh water with a volume of 95% of the ammonia oxime process wastewater are obtained. The COD of the concentrate is 64150 mg / L, the concentration of the detected substance as H2O2 is 120000 mg / L, and the B / C ratio is 0.01. The COD of the fresh water is 800 mg / L, and the B / C ratio is 0.65. The fresh water can be directly treated in the company's existing wastewater treatment plant.

[0033] (2) The concentrate obtained in step (1) is mixed with organic wastewater (petrochemical wastewater from a petrochemical enterprise, with a COD of 18000 mg / L and a B / C ratio of 0.02) to obtain mixed wastewater. The ratio of COD to H2O2 content in the mixed wastewater is 1:0.4, and the H2O2 content in the mixed wastewater is 9000 mg / L. Ferrous sulfate (first catalyst) is added to the mixed wastewater to make the ferrous sulfate content in the mixed wastewater 2000 mg / L. The pH of the mixed wastewater is adjusted to 6 to obtain pre-oxidized mixed wastewater.

[0034] (3) Activated carbon loaded with cerium metal (second catalyst) is packed into a stainless steel reactor of a small continuous fixed-bed reactor. Based on the total weight of the activated carbon, the content of cerium metal (calculated as cerium element) is 0.8% by weight, and the filling amount of the second catalyst in the reactor is 80%. The pre-oxidized mixed wastewater obtained in step (2) is sent to the fixed-bed reactor for wet oxidation treatment. At the same time, air is introduced into the mixed wastewater. The amount of air introduced is 1.05 times the amount of oxidant required to increase the COD value of the mixed wastewater. The wet oxidation treatment temperature is 160℃, the pressure is 2.9MPa, and the volumetric liquid hourly space velocity is 0.6h. -1 The treated wastewater 1.

[0035] The COD value of the treated wastewater 1 was 3765 mg / L, and the B / C ratio was 0.33.

[0036] Example 2

[0037] Same as Example 1, except that in step (3), the temperature of wet oxidation treatment is 200°C, and the treated wastewater 2 is obtained. The COD value of the treated wastewater 2 is 3346 mg / L and the B / C value is 0.36.

[0038] Example 3

[0039] Same as Example 1, except that in step (3), the air flow rate is 1.1 times the amount of oxidant required to increase the COD value of the mixed wastewater, the pressure of wet oxidation treatment is 3.04 MPa, and the treated wastewater 3 is obtained. The COD value of the treated wastewater 3 is 3031 mg / L, and the B / C value is 0.37.

[0040] Example 4

[0041] Same as Example 1, except that in step (3), the volumetric liquid hourly space velocity (LHSV) of the wet oxidation treatment is 0.4 h⁻¹. -1 Wastewater 4 was obtained after treatment. The COD value of wastewater 4 was 3526 mg / L and the B / C ratio was 0.35.

[0042] Example 5

[0043] Same as Example 1, except that: the content of the detected substance in the mixed wastewater in step (2) is 18000 mg / L, and the treated wastewater 5 is obtained. The COD value of the treated wastewater 5 is 2637 mg / L, and the B / C value is 0.41.

[0044] Example 6

[0045] Same as Example 1, except that in step (2), the content of ferrous sulfate in the mixed wastewater is 10000 mg / L, and the treated wastewater 6 is obtained. The COD value of the treated wastewater 6 is 2351 mg / L, and the B / C value is 0.42.

[0046] Example 7

[0047] Same as in Example 1, except that in step (3), the second catalyst is activated carbon loaded with lanthanum metal. Based on the total weight of the activated carbon, the content of lanthanum metal is 1% by weight, and the treated wastewater 7 is obtained. The COD value of the treated wastewater 7 is 4052 mg / L, and the B / C value is 0.32.

[0048] Example 8

[0049] Same as Example 1, except that: in step (1), the volume of the concentrate is 0.5% of the volume of the ammonia oxime process wastewater, and the COD of the obtained ammonia oxime desalinated water is 1500 mg / L and the B / C ratio is 0.21; in step (2), the concentrate is mixed with organic wastewater, and the ratio of COD to the content of the detected substance calculated as H2O2 in the mixed wastewater is 1:0.37, and the content of the detected substance calculated as H2O2 in the mixed wastewater is 8500 mg / L, and finally the treated wastewater 8 is obtained, with a COD value of 3975 mg / L and a B / C ratio of 0.32.

[0050] Example 9

[0051] Similar to Example 1, the only difference is that in step (2), the ratio of COD to the content of the detected substance calculated as H2O2 in the mixed wastewater is 1:5, resulting in treated wastewater 9. The COD value of treated wastewater 9 is 2780 mg / L, and the B / C value is 0.31.

[0052] Example 10

[0053] Similar to Example 1, the only difference is that in step (2), the ratio of COD to the content of the detected substance calculated as H2O2 in the mixed wastewater is 1:8, resulting in treated wastewater 10. The COD value of treated wastewater 10 is 2570 mg / L, and the B / C value is 0.26.

[0054] Example 11

[0055] Similar to Example 1, except that step (1) is not performed and the concentrate of the ammonium oxime process wastewater is not added to the organic wastewater in step (2), resulting in treated wastewater 11 with a COD value of 4762 mg / L and a B / C value of 0.28.

[0056] Example 12

[0057] Similar to Example 1, except that step (1) is not performed and the concentrate of the ammonia oxime process wastewater is not added to the organic wastewater in step (2). Instead, hydrogen peroxide (mass fraction of 12%) with the same volume as the concentrate is mixed with the organic wastewater to obtain treated wastewater 12. The COD value of treated wastewater 12 is 4325 mg / L and the B / C value is 0.29.

[0058] Example 13

[0059] Same as Example 1, except that: step (1) is not performed, and the concentrate of the ammonium oxime process wastewater is not added to the organic wastewater in step (2). The pH of the organic wastewater is adjusted to 7.5 to obtain treated wastewater 13. The COD value of treated wastewater 13 is 4749 mg / L and the B / C value is 0.28.

[0060] Example 14

[0061] Same as Example 1, except that: step (1) is not performed, and the concentrate of the ammonium oxime process wastewater is not added to the organic wastewater in step (2). The ferrous sulfate content in the organic wastewater is 10000 mg / L, resulting in treated wastewater 14. The COD value of treated wastewater 14 is 5107 mg / L, and the B / C value is 0.26.

[0062] Example 15

[0063] Similar to Example 1, except that step (1) is not performed, and in step (2), the concentrate of the ammonia oxime process wastewater is not added to the organic wastewater. Instead, hydrogen peroxide (mass fraction of 12%) with the same volume as the concentrate is mixed with the organic wastewater. The ferrous sulfate content in the mixed solution is 10000 mg / L, resulting in treated wastewater 15. The COD value of treated wastewater 15 is 4128 mg / L, and the B / C value is 0.3.

[0064] Comparative Example 1

[0065] Similar to Example 1, the only difference is that in step (2), ferrous sulfate is not added to the mixed wastewater (i.e., the first catalyst is not added), resulting in wastewater 1 after comparative treatment. The COD value of wastewater 1 after comparative treatment is 8846 mg / L, and the B / C value is 0.21.

[0066] Comparative Example 2

[0067] Similar to Example 1, the only difference is that: the content of ferrous sulfate in the mixed wastewater in step (2) is 10000 mg / L; the fixed bed reactor in step (3) is not filled with a support loaded with cerium metal (i.e., no second catalyst is added), resulting in wastewater 2 after comparative treatment. The COD value of wastewater 2 after comparative treatment is 6843 mg / L, and the B / C value is 0.23.

[0068] Comparative Example 3

[0069] Similar to Example 1, the only difference is that: ferrous sulfate and ferric sulfate are added to the mixed wastewater obtained in step (2) as a mixed catalyst, the weight ratio of ferrous sulfate and ferric sulfate is 1:1, and the content of the mixed catalyst in the mixed wastewater is 4000 mg / L; the fixed bed reactor in step (3) is not filled with a support loaded with cerium metal (i.e., no second catalyst is added), and wastewater 3 after comparative treatment is obtained. The COD value of wastewater 3 after comparative treatment is 5370 mg / L, and the B / C value is 0.24.

[0070] Comparative Example 4

[0071] Same as Example 1, except that in step (2), the pH of the mixed wastewater is adjusted to 7.5 to obtain treated wastewater 13, the COD value of treated wastewater 13 is 6832 mg / L, and the B / C value is 0.23.

[0072] The results above show that, compared to Comparative Examples 1-3, Examples 1-15, which used homogeneous transition metal salts and heterogeneous rare earth metal-supported carriers as mixed catalysts for wet oxidation treatment of organic wastewater, effectively reduced the content of recalcitrant organic matter in the wastewater, improved biodegradability, and resulted in treated wastewater with lower COD and higher B / C ratios, making it suitable for direct discharge into wastewater treatment plants. In contrast, Comparative Examples 1-3 did not simultaneously use the first and second catalysts, resulting in wastewater with higher COD and lower B / C ratios (<0.25), indicating poorer biodegradability and unsuitability for direct discharge into wastewater treatment plants.

[0073] The preferred embodiments of this disclosure have been described in detail above. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0074] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0075] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A method for wet oxidation treatment of organic wastewater, characterized in that, The method includes: mixing concentrated organic wastewater and ammonia oxime process wastewater to obtain mixed wastewater, adjusting the pH of the mixed wastewater to below 6; subjecting the mixed wastewater to wet oxidation treatment in the presence of a catalyst; wherein the ratio of COD to the content of the detected substance calculated as H2O2 in the mixed wastewater is 1:(0.1~5), and the content of the detected substance calculated as H2O2 is 300~22000 mg / L; The catalyst includes a first catalyst and a second catalyst, the first catalyst including a soluble transition metal salt, and the second catalyst including a support and a rare earth metal supported on the support. The soluble transition metal salt is selected from one or more of soluble iron salts, soluble cobalt salts, soluble nickel salts, and soluble platinum salts; the support is selected from one or more of activated carbon, molecular sieves, and activated coke; and the rare earth metal is selected from cerium and / or lanthanum.

2. The method according to claim 1, characterized in that, The soluble transition metal salt is a soluble iron salt.

3. The method according to claim 2, characterized in that, The soluble transition metal salt is ferrous sulfate.

4. The method according to claim 1, characterized in that, The content of soluble transition metal salts in the mixed wastewater is 100~12000 mg / L.

5. The method according to claim 4, characterized in that, The content of soluble transition metal salts in the mixed wastewater is 500~11000 mg / L.

6. The method according to claim 5, characterized in that, The content of soluble transition metal salts in the mixed wastewater is 3000~10000 mg / L.

7. The method according to claim 1, characterized in that, The carrier is activated carbon, and the rare earth metal is cerium.

8. The method according to claim 1, characterized in that, Based on the total weight of the carrier, the content of the rare earth metal, calculated as a metal element, is 0.2 to 5% by weight.

9. The method according to claim 8, characterized in that, Based on the total weight of the carrier, the content of the rare earth metal, calculated as a metal element, is 0.3 to 4% by weight.

10. The method according to claim 1, characterized in that, The ratio of COD to H2O2 content in the mixed wastewater is 1:(0.3~2), and the content of H2O2 content is 1000~20000 mg / L.

11. The method according to claim 10, characterized in that, The content of the substance, calculated as H2O2, is 10,000~18,000 mg / L.

12. The method according to claim 1, characterized in that, The organic wastewater has a COD of 500~50000 mg / L and a B / C ratio of 0~0.3; The COD of the ammonia oxime industrial wastewater is 300~30000 mg / L, the content of the detected substances calculated as H2O2 is 200~30000 mg / L, and the B / C ratio is 0~0.

3.

13. The method according to claim 12, characterized in that, The organic wastewater has a COD of 1000~30000 mg / L and a B / C ratio of 0~0.2; The COD of the ammonia oxime industrial wastewater is 500~15000 mg / L, the content of the detected substances calculated as H2O2 is 500~15000 mg / L, and the B / C ratio is 0~0.

2.

14. The method according to claim 1, characterized in that, The method for preparing the concentrate includes: concentrating the wastewater from the ammonia oxime process using a vacuum distillation method or a membrane concentration method to obtain the concentrate and fresh water.

15. The method according to claim 14, characterized in that, The volume of the concentrate is 1 to 10% of the volume of the ammonia oxime process wastewater.

16. The method according to claim 14, characterized in that, The vacuum distillation is carried out at a temperature of 50~100℃ for 0.2~10h and a vacuum degree of 0.01~0.1KPa.

17. The method according to claim 16, characterized in that, The vacuum distillation is carried out at a temperature of 60~90℃ for 0.5~5h and a vacuum degree of 0.02~0.08KPa.

18. The method according to claim 1, characterized in that, The conditions for the wet oxidation treatment include: a temperature of 80~400℃ and a pressure of 1.0~15MPa; The wet oxidation process is carried out in a reactor, which may be a fixed-bed reactor, a fluidized-bed reactor, or a batch reactor.

19. The method according to claim 18, characterized in that, The conditions for the wet oxidation treatment include: a temperature of 100~300℃ and a pressure of 1.5~10MPa; The wet oxidation process is carried out in a fixed-bed reactor with a volumetric liquid hourly space velocity (LHSV) of 0.05–30 h⁻¹. -1 .

20. The method according to claim 19, characterized in that, The conditions for the wet oxidation treatment include: a temperature of 120~250℃ and a pressure of 2~7MPa; The volumetric liquid hourly space velocity (LISH) of the reaction was 0.2–10 h⁻¹. -1 .

21. The method according to claim 1, characterized in that, The method further includes: introducing an oxidizing gas into the mixed wastewater, wherein the amount of oxidizing gas introduced is 1 to 3 times the amount of oxidant required to increase the COD value of the mixed wastewater.

22. The method according to claim 21, characterized in that, The amount of oxidizing gas introduced is 1.05 to 1.5 times the amount of oxidant required to reduce the COD value in the mixed wastewater.

23. The method according to claim 21, characterized in that, The oxidizing gas includes oxygen and / or air.