A method for stabilizing oil refinery concentrated sludge

Abstract

This disclosure relates to a method for stabilizing concentrated oil refinery sludge. The method includes: heating a mixture of concentrated oil refinery sludge and a treatment agent under acidic conditions to obtain a treated material; wherein the concentrated oil refinery sludge has a moisture content of 98-98.5% by weight, a total suspended solids content of 15-20 g / L, and a volatile suspended solids content of 10-15 g / L; the treatment agent is obtained by pretreating ammonia oxime wastewater. This disclosure uses a treatment agent obtained after pretreating ammonia oxime wastewater to treat concentrated oil refinery sludge, which can significantly reduce the organic matter content and moisture content of the sludge cake, achieving substantial stabilization of the concentrated oil refinery sludge, while simultaneously realizing the resource utilization of the ammonia oxime wastewater.

Description

Technical Field

[0001] This disclosure relates to a method for stabilizing oil refinery concentrated sludge. Background Technology

[0002] Wastewater treatment plants in my country commonly use activated sludge technology, which generates a large amount of residual biochemical sludge during the treatment process. This residual sludge contains numerous toxic and harmful substances such as microorganisms, viruses, and parasites, requiring volume reduction treatment before being discharged into the environment to minimize pollution. Currently, the general method for treating residual biochemical sludge is: concentration—conditioning—dewatering—transportation. The transported sludge has a high water content (generally between 80% and 85%), is bulky, and contains high levels of viruses and bacteria, increasing the cost of subsequent sludge disposal (such as landfill or incineration).

[0003] Sludge thermal hydrolysis technology can disintegrate microbial flocs, break down cell structures, and hydrolyze organic macromolecules such as proteins, polysaccharides, and lipids, thereby reducing the solid content in sludge. Simultaneously, thermal hydrolysis also reduces the viscosity of sludge particles and alters the water distribution characteristics within the sludge, thus improving its dewatering capacity. CN102718384A discloses a method for treating sludge using alkaline catalytic thermal hydrolysis. This method improves sludge hydrolysis efficiency by adding alkaline substances to the sludge, facilitating rapid cell breakage and rapid hydrolysis of organic matter. However, this method places high demands on the reactor material and can cause scaling, limiting the reactor's long-term operation. Therefore, it is necessary to develop economically feasible biochemical sludge reduction technologies to significantly reduce the volume of excess sludge and minimize environmental harm. Summary of the Invention

[0004] The purpose of this disclosure is to provide a method for stabilizing refinery concentrate sludge, thereby achieving significant stabilization of refinery concentrate sludge.

[0005] To achieve the above objectives, this disclosure provides a method for stabilizing refinery concentrate sludge, the method comprising:

[0006] Under acidic conditions, oil refinery concentrated sludge is mixed with a treatment agent and heated to obtain the treated material;

[0007] The oil refinery concentrated sludge has a water content of 98-98.5% by weight, a total suspended solids content of 15-20 g / L, and a volatile suspended solids content of 10-15 g / L; the treatment agent is obtained by pretreating the ammonia oxime wastewater.

[0008] Optionally, the preparation steps of the treatment agent include:

[0009] The ammonia oxime wastewater was concentrated to obtain the concentrated material.

[0010] A coagulant is added to the concentrated material to allow it to settle, and the sediment is removed to obtain the treatment agent.

[0011] Optionally, the pH value of the ammonia oxime wastewater is 12-13.

[0012] Optionally, the concentration conditions include: -0.07 MPa to -0.08 MPa, temperature of 60 to 95°C, and concentration factor of 20 to 70 times, preferably 30 to 60 times.

[0013] Optionally, the sedimentation conditions include: pH value of 6-8 and time of 15-120 min;

[0014] Preferably, the sedimentation conditions include: pH value of 6.5-7 and time of 30-60 min.

[0015] Optionally, based on the volume of the concentrated material, the amount of coagulant used is 20-80 mg / L, preferably 40-60 mg / L;

[0016] The coagulant is an aluminum salt, preferably aluminum sulfate and / or aluminum chloride.

[0017] Optionally, the acidic conditions include a pH value of 3 to 7, preferably 4.5 to 6.5.

[0018] Optionally, based on the volume of the oil refining concentrated sludge, the dosage of the treatment agent is 10-30 mL / L, preferably 15-25 mL / L.

[0019] Optionally, the conditions for the heat treatment include: a temperature of 80–160°C and a time of 30–360 min;

[0020] Preferably, the conditions for the heat treatment include: a temperature of 90–140°C and a time of 60–120 min.

[0021] Optionally, the method further includes:

[0022] The processed material is subjected to solid-liquid separation to obtain liquid phase material and solid phase material;

[0023] The liquid material is fed into the front-end wastewater treatment device.

[0024] Through the above technical solution, this disclosure uses the treatment agent obtained after pretreatment of ammonia oxime wastewater to treat oil refinery concentrated sludge, which can significantly reduce the organic matter content and sludge cake moisture content of the sludge, achieve significant stabilization treatment of oil refinery concentrated sludge, and realize the resource utilization of ammonia oxime wastewater.

[0025] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Detailed Implementation

[0026] 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.

[0027] This disclosure provides a method for stabilizing oil refinery concentrated sludge, the method comprising:

[0028] Under acidic conditions, oil refinery concentrated sludge is mixed with a treatment agent and heated to obtain the treated material;

[0029] The oil refinery concentrated sludge has a water content of 98-98.5% by weight, a total suspended solids content of 15-20 g / L, and a volatile suspended solids content of 10-15 g / L; the treatment agent is obtained by pretreating the ammonia oxime wastewater.

[0030] According to this disclosure, the oil refinery concentrated sludge refers to solid, semi-solid, and liquid waste generated during wastewater treatment, primarily activated sludge discharged from the thickening tank in the activated sludge system, with a pH value of 7.1–7.7. The method of this disclosure is particularly suitable for oil refinery concentrated sludge with high suspended solids content. Specifically, the water content of the oil refinery concentrated sludge is 98–98.5% by weight, the total suspended solids (SS) content is 15–20 g / L, the volatile suspended solids (VSS) content is 10–15 g / L, and the VSS / SS ratio is 67–75% by weight. Using this treatment agent can effectively remove organic matter from the oil refinery concentrated sludge, reduce the moisture content of the sludge cake, and the treated material has a high BOD5 / COD ratio.

[0031] According to this disclosure, the material obtained after appropriate pretreatment of ammonia oxime wastewater can be used as a treatment agent for oil refinery concentrated sludge. In one embodiment, the preparation steps of the treatment agent include:

[0032] The ammonia oxime wastewater was concentrated to obtain the concentrated material.

[0033] A coagulant is added to the concentrated material to allow it to settle, and the sediment is removed to obtain the treatment agent.

[0034] The ammonium oxime wastewater refers to the wastewater generated during the production of cyclohexanone oxime from cyclohexanone in the caprolactam production process. This disclosure does not specify any particular requirements for the composition or properties of the ammonium oxime wastewater and is widely applicable to various caprolactam production wastewaters. For example, the COD of the ammonium oxime wastewater can be 2000–12000 mg / L, the BOD5 / COD ratio can be 0–0.01, and the peroxide content can be 6120 mg / L–9171 mg / L.

[0035] In a preferred embodiment, the pH value of the ammonia oxime wastewater is 12-13. The treatment agent obtained using alkaline ammonia oxime wastewater as raw material is particularly suitable for treating oil refinery concentrated sludge. In this case, the method may further include adjusting the pH value of the ammonia oxime wastewater to 12-13 using a pH adjuster before concentration. The pH adjuster may be, for example, sodium hydroxide, potassium hydroxide, etc.

[0036] The concentration process can employ methods commonly used in the art to increase the concentration of substances in wastewater, such as evaporation concentration. The concentration conditions are designed to ensure that the concentrated material reaches a suitable degree of concentration, avoiding adverse effects on subsequent utilization due to excessively high salt content in the wastewater. Specifically, the concentration conditions may include: a pressure of -0.07 MPa to -0.08 MPa, a temperature of 60–95°C, and a concentration factor of 20–70 times, preferably 30–60 times. The resulting concentrated material generally contains flocculent matter, eliminating the need for solid-liquid separation and allowing for direct sedimentation.

[0037] The sedimentation conditions may include: a pH value of 6–8 and a sedimentation time of 15–120 min. Preferably, the sedimentation conditions include: a pH value of 6.5–7 and a sedimentation time of 30–60 min.

[0038] Based on the volume of the concentrated material, the dosage of the coagulant can be 20–80 mg / L, preferably 40–60 mg / L. In one embodiment, the coagulant is an aluminum salt. Using aluminum salt as a coagulant does not introduce additional impurities and is beneficial for improving sedimentation. Preferably, the aluminum salt is aluminum sulfate and / or aluminum chloride.

[0039] The sediment is typically flocculent, and the clear liquid obtained after removing the sediment is the treatment agent. Specifically, methods for removing sediment include, for example, filtration and centrifugation.

[0040] In this embodiment, by concentrating and settling the ammonia oxime wastewater and removing the sediment, a treatment agent for treating oil refinery concentrated sludge can be obtained, thus realizing the resource utilization of ammonia oxime wastewater. The properties of the treatment agent include: COD of 53140 mg / L to 132850 mg / L, and BOD5 / COD of 0 to 0.01.

[0041] According to this disclosure, the acidic conditions may include a pH value of 3 to 7, preferably 4.5 to 6.5.

[0042] According to this disclosure, the treatment agent can achieve excellent treatment results with a small dosage. Specifically, based on the volume of the oil refinery concentrated sludge, the dosage of the treatment agent can be 10-30 mL / L, preferably 15-25 mL / L.

[0043] Compared to traditional sludge hydrolysis technology, the heating treatment disclosed herein can be carried out under milder conditions. Specifically, the heating treatment conditions may include: a temperature of 80–160°C and a time of 30–360 min; preferably, the heating treatment conditions include: a temperature of 90–140°C and a time of 60–120 min.

[0044] According to this disclosure, the treated material exhibits significantly reduced organic matter content and moisture content, demonstrating good biodegradability. The liquid phase material after solid-liquid separation can be returned to the upstream wastewater treatment unit, thereby effectively reducing sludge discharge. In one embodiment, the method further includes solid-liquid separation of the treated material to obtain a liquid phase material and a solid phase material; and feeding the liquid phase material into the upstream wastewater treatment unit, preferably adjusting the pH value of the liquid phase material to 6.8–7.2 before feeding it into the upstream wastewater treatment unit. The upstream wastewater treatment unit refers to a device used for treating domestic sewage and / or industrial wastewater, and the oil refinery concentrated sludge is a downstream product of this upstream wastewater treatment unit. Specifically, the COD of the liquid phase material can be 11000 mg / L–12000 mg / L, and the BOD5 / COD ratio can be 0.5–0.7. The moisture content of the solid phase material can be 56–60% by weight, and it can be further treated as needed, such as landfilling.

[0045] This disclosure describes the use of a treatment agent obtained by pretreating ammonia oxime wastewater to treat oil refinery concentrated sludge, which can significantly reduce the organic matter content and sludge cake moisture content of the sludge, achieve significant stabilization of oil refinery concentrated sludge, and realize the resource utilization of ammonia oxime wastewater.

[0046] The present disclosure is further illustrated by the following examples, but is not intended to limit the present disclosure.

[0047] In the following examples, the ammonia oxime wastewater was sourced from industrial wastewater, with a COD of 2625 mg / L, a BOD5 / COD ratio of 0.01, and a peroxide content of 6171 mg / L. The refinery concentrate sludge was sourced from industrial wastewater generated by a refining and chemical enterprise, with a pH of 7.1, a water content of 98.39% by weight, a total suspended solids (SS) content of 16.1 g / L, a volatile suspended solids (VSS) content of 11.6 g / L, and a VSS / SS ratio of 72% by weight.

[0048] COD analysis method: HJ 828-2017 Determination of Chemical Oxygen Demand in Water by dichromate method.

[0049] BOD5 analysis method: HJ 505-2009 Determination of five-day biochemical oxygen demand (BOD5) in water quality - dilution and inoculation method.

[0050] Organic matter content analysis method: CJT221-2005 Method for testing sludge from urban wastewater treatment plants.

[0051] Method for analyzing the moisture content of sludge cake: CJT221-2005 Method for testing sludge from urban wastewater treatment plants.

[0052] Organic matter removal rate = (1 - VSS of treated sludge / VSS of untreated sludge) × 100%

[0053] Sludge reduction rate = (1 - mass of sludge after treatment / mass of sludge before treatment) × 100%

[0054] Example 1

[0055] Take 600 mL of ammonia oxime wastewater, maintain the pH value of the wastewater at 12, and evaporate and concentrate it at 95℃ and -0.08 MPa. After concentrating it 30 times, the concentrated material is obtained. Add aluminum sulfate solution (concentration of 1000 mg / L) to the concentrated material. The amount of aluminum sulfate is 50 mg / L based on the volume of the concentrated material. Allow it to settle for 45 min at a pH value of 6.9. Filter to remove the precipitate and take the clear liquid to obtain the treatment agent of this embodiment (COD of 67200 mg / L, BOD5 / COD of 0).

[0056] The pH of the concentrated oil refinery sludge was adjusted to 5.5, and the above-mentioned treatment agent was added for heating treatment. Based on the volume of the concentrated oil refinery sludge, the dosage of the treatment agent was 15 mL / L, the heating temperature was 140℃, and the time was 60 min. After treatment, the organic matter removal rate was measured using the treated material. After solid-liquid separation, the moisture content and sludge reduction rate of the solid phase material (sludge cake) were calculated. The BOD5 / COD ratio of the liquid phase material (supernatant) was measured. After the pH of the supernatant was adjusted back to 7, it could be returned to the upstream wastewater treatment unit. The results are listed in Table 1.

[0057] Example 2

[0058] Take 600 mL of ammonia oxime wastewater, maintain the pH value of the wastewater at 12, and evaporate and concentrate it at 95℃ and -0.08 MPa. After 40 times concentration, the concentrated material is obtained. Add aluminum sulfate solution (concentration of 1000 mg / L) to the concentrated material. The amount of aluminum sulfate is 40 mg / L based on the volume of the concentrated material. Allow it to settle for 50 min at pH 7.5. Filter to remove the precipitate and take the clear liquid to obtain the treatment agent of this embodiment (COD of 90400 mg / L, BOD5 / COD of 0).

[0059] The pH of the concentrated oil refinery sludge was adjusted to 6.5, and the above-mentioned treatment agent was added for heating treatment. Based on the volume of the concentrated oil refinery sludge, the dosage of the treatment agent was 18 mL / L, the heating temperature was 130℃, and the time was 60 min. After treatment, the organic matter removal rate was tested on the treated material. After solid-liquid separation, the moisture content of the sludge cake and the sludge reduction rate were calculated. The BOD5 / COD ratio of the supernatant was measured. After the pH of the supernatant was adjusted back to 6.8, it could be returned to the upstream wastewater treatment unit. The results are listed in Table 1.

[0060] Example 3

[0061] Take 600 mL of ammonia oxime wastewater, maintain the pH value of the wastewater at 12, and evaporate and concentrate it at 85℃ and -0.09 MPa. After concentrating it 50 times, the concentrated material is obtained. Add aluminum sulfate solution (concentration of 1000 mg / L) to the concentrated material. Based on the volume of the concentrated material, the amount of aluminum sulfate is 60 mg / L. Allow it to settle for 60 min at a pH value of 6.5. Filter to remove the precipitate, and take the clear liquid to obtain the treatment agent of this embodiment (COD of 115000 mg / L, BOD5 / COD of 0).

[0062] The pH of the concentrated oil refinery sludge was adjusted to 4.5, and the above-mentioned treatment agent was added for heating treatment. Based on the volume of the concentrated oil refinery sludge, the dosage of the treatment agent was 25 mL / L, the heating temperature was 90℃, and the time was 100 min. After treatment, the organic matter removal rate was tested on the treated material. After solid-liquid separation, the moisture content of the sludge cake and the sludge reduction rate were calculated. The BOD5 / COD ratio of the supernatant was measured. After the pH of the supernatant was adjusted back to 7, it could be returned to the upstream wastewater treatment unit. The results are listed in Table 1.

[0063] Example 4

[0064] The oil refinery concentrate sludge was treated according to the method in Example 1, except that the amount of treatment agent used was 10 mL / L, based on the volume of the oil refinery concentrate sludge.

[0065] After treatment, the treated material was tested to determine the organic matter removal rate. After solid-liquid separation, the moisture content of the sludge cake and the sludge reduction rate were calculated. The BOD5 / COD ratio of the supernatant was measured. After the pH of the supernatant was adjusted to 7.2, it could be sent back to the front-end wastewater treatment device. The results are listed in Table 1.

[0066] Example 5

[0067] The oil refinery concentrate sludge was treated according to the method in Example 1, except that the amount of treatment agent used was 30 mL / L, based on the volume of the oil refinery concentrate sludge.

[0068] After treatment, the treated material was tested to determine the organic matter removal rate. After solid-liquid separation, the moisture content of the sludge cake and the sludge reduction rate were calculated. The BOD5 / COD ratio of the supernatant was measured. After the pH of the supernatant was adjusted to 7, it could be sent back to the front-end wastewater treatment device. The results are listed in Table 1.

[0069] Example 6

[0070] The oil refinery concentrated sludge was treated according to the method in Example 1, except that the pH value of the oil refinery concentrated sludge was adjusted to 7, the heating temperature was 150°C, and the time was 300 min.

[0071] After treatment, the treated material was tested to determine the organic matter removal rate. After solid-liquid separation, the moisture content of the sludge cake and the sludge reduction rate were calculated. The BOD5 / COD ratio of the supernatant was measured. After the pH of the supernatant was adjusted to 7, it could be sent back to the front-end wastewater treatment device. The results are listed in Table 1.

[0072] Comparative Example 1

[0073] Take 600 mL of ammonia oxime wastewater, maintain the pH value of the wastewater at 12, and evaporate and concentrate it at 95℃ and -0.08 MPa. After concentrating it 30 times, the concentrated material is obtained. Filter the concentrated material to remove flocculent matter, and then add aluminum sulfate solution (concentration of 1000 mg / L). Based on the volume of the filtered clear liquid, the amount of aluminum sulfate is 50 mg / L. Settle at pH 6.9 for 45 min, filter to remove the precipitate, and take the clear liquid to obtain the treatment agent of this comparative example (COD of 71100 mg / L, BOD5 / COD of 0).

[0074] The pH of the concentrated oil refinery sludge was adjusted to 5.5, and the above-mentioned treatment agent was added for heating treatment. Based on the volume of the concentrated oil refinery sludge, the dosage of the treatment agent was 15 mL / L, the heating temperature was 140℃, and the time was 60 min. After treatment, the organic matter removal rate was tested on the treated material. After solid-liquid separation, the moisture content of the sludge cake and the sludge reduction rate were calculated. The BOD5 / COD ratio of the supernatant was also measured. The results are listed in Table 1.

[0075] Comparative Example 2

[0076] Take 600 mL of ammonia oxime wastewater, maintain the pH value of the wastewater at 12, and evaporate and concentrate it at 95℃ and -0.08 MPa. After concentrating it 30 times, the concentrated material is obtained. After filtering the concentrated material to remove flocculent matter, the clear liquid is taken to obtain the treatment agent of this comparative example (COD is 75800 mg / L, BOD5 / COD is 0).

[0077] The pH of the concentrated oil refinery sludge was adjusted to 5.5, and the above-mentioned treatment agent was added for heating treatment. Based on the volume of the concentrated oil refinery sludge, the dosage of the treatment agent was 15 mL / L, the heating temperature was 140℃, and the time was 60 min. After treatment, the organic matter removal rate was tested on the treated material. After solid-liquid separation, the moisture content of the sludge cake and the sludge reduction rate were calculated. The BOD5 / COD ratio of the supernatant was also measured. The results are listed in Table 1.

[0078] Comparative Example 3

[0079] This comparative example uses hydrogen peroxide at a concentration of 27% by weight as the treatment agent.

[0080] The pH of the concentrated oil refinery sludge was adjusted to 5.5, and the above-mentioned treatment agent was added for heating treatment. Based on the volume of the concentrated oil refinery sludge, the dosage of the treatment agent was 15 mL / L, the heating temperature was 140℃, and the time was 60 min. After treatment, the organic matter removal rate was tested on the treated material. After solid-liquid separation, the moisture content of the sludge cake and the sludge reduction rate were calculated. The BOD5 / COD ratio of the supernatant was also measured. The results are listed in Table 1.

[0081] Comparative Example 4

[0082] Take 600 mL of ammonia oxime wastewater, maintain the pH value of the wastewater at 12, do not concentrate, directly add aluminum sulfate, based on the volume of wastewater, the amount of aluminum sulfate is 50 mg / L, and allow it to settle for 45 min at a pH value of 6.9. Filter to remove the precipitate, and take the clear liquid to obtain the treatment agent of this comparative example.

[0083] The pH of the residual biological sludge was adjusted to 5.5, and the above-mentioned treatment agent was added for heating treatment. Based on the volume of the residual biological sludge, the dosage of the treatment agent was 15 mL / L, the heating temperature was 140℃, and the time was 60 min. After treatment, the organic matter removal rate was tested, the moisture content of the sludge cake and the sludge reduction rate were calculated after solid-liquid separation, and the BOD5 / COD of the supernatant was measured. The results are listed in Table 1.

[0084] Comparative Example 5

[0085] Take 600 mL of ammonia oxime wastewater, maintain the pH value of the wastewater at 12, and evaporate and concentrate it at 95℃ and -0.08 MPa. After concentrating it 30 times, the concentrated material is obtained. Filter the concentrated material to remove flocculent matter, and then add aluminum sulfate. Based on the volume of the filtered clear liquid, the amount of aluminum sulfate is 50 mg / L. Settle at pH 6.9 for 45 min, filter to remove the precipitate, and take the clear liquid to obtain the treatment agent of this comparative example.

[0086] The pH of the residual biological sludge was adjusted to 8, and the above-mentioned treatment agent was added for heating treatment. Based on the volume of the residual biological sludge, the dosage of the treatment agent was 15 mL / L, the heating temperature was 140℃, and the time was 60 min. After treatment, the organic matter removal rate was tested, the moisture content of the sludge cake and the sludge reduction rate were calculated after solid-liquid separation, and the BOD5 / COD of the supernatant was measured. The results are listed in Table 1.

[0087] Table 1

[0088]

[0089]

[0090] As shown in Table 1, the method disclosed in this paper for treating oil refinery concentrated sludge has a high organic matter removal rate, low sludge cake moisture content, and high sludge reduction rate. At the same time, the treated liquid phase material has a high BOD5 / COD value and can be returned to the front-end wastewater treatment. The solid phase material has a moisture content of less than 60% by weight and can be sanitarily landfilled according to the requirements of GB / T23485-2009 standard, which effectively reduces the production of oil refinery concentrated sludge.

[0091] 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.

[0092] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0093] 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 stabilizing oil refinery concentrated sludge, characterized in that, The method includes: Under acidic conditions, oil refinery concentrated sludge is mixed with a treatment agent and heated to obtain the treated material; The oil refining concentrated sludge has a water content of 98-98.5% by weight, a total suspended solids content of 15-20 g / L, and a volatile suspended solids content of 10-15 g / L. The preparation steps of the treatment agent include: The ammonia oxime wastewater is concentrated to obtain a concentrated material; the pH value of the ammonia oxime wastewater is 12~13, and the peroxide content is 6120mg / L~9171mg / L; the concentration conditions include: pressure of -0.07MPa to -0.08MPa, temperature of 60~95℃, and concentration ratio of 20~70 times. A coagulant is added to the concentrated material to allow it to settle, and the sediment is removed to obtain the treatment agent.

2. The method according to claim 1, wherein, The concentration conditions include a concentration factor of 30 to 60 times.

3. The method according to claim 1, wherein, The sedimentation conditions include: pH value of 6-8 and time of 15-120 min.

4. The method according to claim 3, wherein, The sedimentation conditions include a pH value of 6.5-7 and a time of 30-60 minutes.

5. The method according to claim 1, wherein, Based on the volume of the concentrated material, the dosage of the coagulant is 20~80 mg / L; The coagulant is an aluminum salt.

6. The method according to claim 5, wherein, Based on the volume of the concentrated material, the dosage of the coagulant is 40~60 mg / L; The aluminum salt is aluminum sulfate and / or aluminum chloride.

7. The method according to claim 1, wherein, The acidic conditions include a pH value of 3 to 7.

8. The method according to claim 7, wherein, The acidic conditions include a pH value of 4.5 to 6.

5.

9. The method according to claim 1, wherein, Based on the volume of the concentrated oil refining sludge, the dosage of the treatment agent is 10~30mL / L.

10. The method according to claim 9, wherein, Based on the volume of the concentrated oil refining sludge, the dosage of the treatment agent is 15~25 mL / L.

11. The method according to claim 1, wherein, The conditions for the heat treatment include: a temperature of 80~160℃ and a time of 30~360min.

12. The method according to claim 11, wherein, The conditions for the heat treatment include: a temperature of 90~140℃ and a time of 60~120min.

13. The method according to claim 1, wherein, The method also includes: The processed material is subjected to solid-liquid separation to obtain liquid phase material and solid phase material; The liquid material is fed into the front-end wastewater treatment device.

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