A method and system for pretreating wastewater from a natural gas acetylene plant concentration process

Abstract

The application discloses a method and system for pretreating wastewater in a concentration process of a natural gas acetylene device, and relates to the technical field of chemical industry. The wastewater in the concentration process is introduced into a concentration wastewater pretreatment tank. A gas stripping area, an aeration area, a phase separation area and a carbon black slurry collection area are sequentially arranged in the concentration wastewater pretreatment tank. The wastewater in the concentration process is step by step disposed in each area of the concentration wastewater pretreatment tank. The application can effectively reduce the COD value of the wastewater in the concentration process of the acetylene device, realize liquid-solid phase separation disposal, avoid pollution of the environment and safety hazards caused by harmful gas resolution, and is suitable for all natural gas acetylene devices. Meanwhile, the method can be used as a typical pretreatment method for wastewater containing solid and gas and having high COD, and has popularization value.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of chemical technology, more particularly to the field of a method and system for pretreating wastewater in the concentration process of a natural gas acetylene device. BACKGROUND

[0002] As an important chemical raw material, acetylene is mainly prepared by the calcium carbide method and the natural gas partial oxidation method. Compared with the calcium carbide method for preparing acetylene, the natural gas acetylene process has the advantages of low energy consumption, full utilization of by-products, and less environmental pollution, and has been widely popularized and applied at home and abroad. In the natural gas acetylene process, natural gas is cracked, compressed, and concentrated to obtain acetylene products.

[0003] In the natural gas acetylene device, natural gas and oxygen are preheated, and a cracking reaction occurs in the reactor (cracking furnace) to generate cracking gas containing acetylene, carbon monoxide, carbon dioxide, hydrogen, higher acetylene, and carbon black. The cracking gas is compressed and sent to the acetylene concentration process. In the concentration process, N-methyl pyrrolidone (NMP) solvent is used to selectively absorb the cracking gas under pressure and normal temperature conditions, and the gas dissolved in the NMP solvent is stepwise desorbed through processes such as pressure reduction, vacuum, and heating. After the above treatment, the mixed gas is separated into three streams: synthesis gas rich in hydrogen and carbon monoxide, product acetylene gas with a purity of about 98.8 (vol%) and higher acetylene gas. To maintain the water balance of the NMP solvent system, the concentration process needs to continuously discharge a stream of production wastewater with a flow rate of about 40 m 3 / h to a wastewater treatment plant.

[0004] The process operating conditions determine that the stream of wastewater is rich in solid carbon black, organic components N-methyl pyrrolidone, benzene, naphthalene, and dissolved higher acetylene (diacetylene, propyne, vinyl acetylene, propadiene), acetylene, carbon monoxide, hydrogen, and other toxic and explosive gases. The stream of wastewater has complex components, high COD value, and high solid content, making it difficult for the downstream wastewater treatment plant to dispose of it. The large amount of harmful substances dissolved in the wastewater are prone to desorption and overflow, which can form a pungent odor in the environment around the wastewater pool and may form a mixed explosive gas in a confined space. This has safety hazards and high environmental risks. SUMMARY

[0005] The present application provides a method and system for pretreating wastewater in the concentration process of a natural gas acetylene device.

[0006] To achieve the above-mentioned purpose, the present application specifically adopts the following technical solutions:

[0007] One aspect of the present application provides a method for pretreating wastewater in the concentration process of a natural gas acetylene device, comprising the following steps:

[0008] S1, the concentrated wastewater of the concentration process enters a concentrated wastewater pretreatment tank, a gas stripping area, an aeration area, a phase separation area and a carbon black slurry collection area are sequentially arranged in the concentrated wastewater pretreatment tank, and the concentrated wastewater of the concentration process is disposed step by step in each area of the concentrated wastewater pretreatment tank;

[0009] S2, the clear liquid at the bottom of the phase separation area is pumped to a wastewater treatment device by a wastewater pump, and the carbon black slurry in the carbon black slurry collection area is pumped to a burning unit for treatment by a carbon black slurry pump;

[0010] S3, the gas sources of the gas stripping area and the aeration area of the concentrated wastewater pretreatment tank are both controllable factory air, and by controlling the gas amount of the factory air, it can be ensured that the combustible gas component in the gas discharged from the top of the pretreatment tank is far below the lower limit of its explosion limit; the top of the gas stripping area is communicated with an exhaust pipeline, the exhaust pipeline is divided into two routes at the end, one pipeline is communicated with a burning furnace through a combustion air pipeline, and the other pipeline is communicated with a water seal device through a water seal communication pipeline; under normal conditions, the gas in the combustion air pipeline is sent to the burning furnace as combustion air for treatment, and the harmful components in the exhaust gas are removed at the same time to realize the recycling of the waste heat value;

[0011] S4, when the burning furnace is in an abnormal condition, an interlock switch valve on the combustion air pipeline is cut off; the gas in the exhaust pipeline is discharged to an activated carbon adsorption tower after breaking through the water seal of the water seal device, and the activated carbon adsorption tower is discharged to a safe place after treatment.

[0012] The present application can effectively reduce the COD value of the concentrated wastewater of the acetylene device, realize liquid-solid phase separation disposal, avoid environmental pollution and safety hazards caused by harmful gas resolution, and is suitable for all natural gas acetylene devices. At the same time, this method can be used as a typical pretreatment method for solid-containing, gas-containing and high-COD wastewater, and has popularization value.

[0013] In one embodiment, the aeration area is divided into a first aeration area and a second aeration area;

[0014] The first aeration area, the second aeration area, the phase separation area and the carbon black slurry collection area are sequentially separated by a first partition, a second partition and a third partition.

[0015] In one embodiment, the detailed process of step S1 is as follows:

[0016] Step S11, the concentrated wastewater of the concentration process enters from the upper part of the concentrated wastewater pretreatment tank and is in countercurrent contact with the rising factory air in the gas stripping area (scattered packed filler) through a distributor, and part of the dissolved gas is resolved into the gas stripping gas; the gas stripping treatment can remove part of the waste gas dissolved in the wastewater;

[0017] Step S12, the wastewater after stripping flows into the first aeration area by gravity, and is preliminarily aerated by the aeration nozzles arranged at the bottom of the area to reduce the COD of the wastewater and further remove the combustible and toxic gases dissolved in the wastewater, and the amount of the waste gas dissolved in the wastewater after the treatment is substantially removed, and the COD of the wastewater is reduced from the initial value;

[0018] Step S13, the wastewater after the preliminary aeration treatment flows into the second aeration area through the bottom opening of the first partition plate arranged in the pretreatment tank, and is further aerated by the high-efficiency aeration nozzles arranged at the bottom of the area, and the COD of the wastewater is further reduced after the treatment.

[0019] Step S14, the wastewater after the two-stage aeration treatment overflows into the phase separation area through the second partition plate arranged in the pretreatment tank, and is separated in the phase separation area, and the carbon black in the wastewater is suspended on the water surface due to the small density, and the height of the phase separation interface is controlled by the interface liquid level meter arranged in the area.

[0020] Step S15, the carbon black slurry suspended on the liquid surface after the phase separation overflows into the carbon black slurry collection area through the third partition plate arranged in the pretreatment tank, and the liquid-solid separation of the wastewater is realized.

[0021] In one embodiment, in step S12, the wastewater after stripping flows into the first aeration area by gravity, and is preliminarily aerated by the 30 groups of row-column distributed aeration nozzles arranged at the bottom of the area to reduce the COD of the wastewater and further remove the combustible and toxic gases dissolved in the wastewater, and the residence time of the wastewater in the area is designed to be 30 minutes, and the amount of the waste gas dissolved in the wastewater after the treatment is substantially removed, and the COD of the wastewater is reduced from the initial value of 1200 ppm to 600 ppm.

[0022] In one embodiment, in step S13, the wastewater after the preliminary aeration treatment flows into the second aeration area through the bottom opening of the first partition plate arranged in the pretreatment tank, and is further aerated by the 60 groups of multi-layer annular distributed high-efficiency aeration nozzles arranged at the bottom of the area, and the residence time of the wastewater in the area is designed to be 50 minutes, and the COD of the wastewater after the treatment can be reduced to below 50 ppm.

[0023] In one embodiment, in step S2, the liquid level in the phase separation area is controlled by the liquid level adjusting valve arranged on the outlet pipeline of the wastewater pump.

[0024] In one embodiment, in step S2, since the amount of the carbon black entering the carbon black slurry collection area is not much, the carbon black slurry in the carbon black slurry collection area is treated by manually opening the carbon black slurry pump at regular time to send to the incineration unit, and the heat value of the carbon black incineration is recovered to produce steam as a byproduct while realizing the waste solid and waste liquid separation treatment.

[0025] Another aspect of the present application provides a system for pre-treating wastewater from a concentration process of a natural gas acetylene plant, which is suitable for the method for pre-treating wastewater from a concentration process of a natural gas acetylene plant.

[0026] In one embodiment, the system comprises a concentration process wastewater inlet pipe, a concentration process wastewater pre-treatment tank, a carbon black slurry pump, a wastewater pump, a incineration unit, a wastewater treatment device, a plant air source, an incineration furnace, a water seal device, and an activated carbon adsorption tower.

[0027] The concentration process wastewater pre-treatment tank comprises a horizontal cavity and a vertical cavity that are in communication with each other, the vertical cavity comprises, from top to bottom, a distributor and a gas stripping area, and the horizontal cavity comprises, in sequence, a first aeration area, a second aeration area, a phase separation area, and a carbon black slurry collection area, which are separated by a first partition, a second partition, and a third partition.

[0028] The concentration process wastewater inlet pipe is connected to the distributor.

[0029] The phase separation area at the bottom is connected to the wastewater treatment device through a wastewater pump and a pipeline, and the carbon black slurry in the carbon black slurry collection area is connected to the incineration unit through a carbon black slurry pump and a pipeline.

[0030] The plant air source is connected to the first aeration area, the second aeration area, and the gas stripping area through pipelines with flow control valves, respectively.

[0031] The top of the vertical cavity is connected through an exhaust pipeline, the end of which is divided into two paths, one of which is connected to the incineration furnace through a combustion air pipeline, and the other is connected to the water seal device through a water seal connection pipeline, and the water seal device is connected to the activated carbon adsorption tower.

[0032] In one embodiment, a stop valve is arranged on the combustion air pipeline, aeration nozzles are arranged at the bottom of the first aeration area, and high-efficiency aeration nozzles are arranged at the bottom of the second aeration area.

[0033] The present application has the following advantages:

[0034] The present application has the following advantages: BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be considered as limiting the scope. Other related drawings can also be obtained by those skilled in the art without creative effort.

[0036] Figure 1 is a structural schematic diagram of a natural gas acetylene device enrichment process wastewater pretreatment system.

[0037] Figure 2 is a layout structural schematic diagram of Figure 1 . DETAILED DESCRIPTION

[0038] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments in the present application without creative effort are within the scope of the present application.

[0040] It should be noted that: similar reference numbers and letters represent similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0041] In the description of the embodiments of the present application, it should be noted that the directions or position relationships indicated by the terms "inner", "outer", "upper", etc. are based on the directions or position relationships shown in the drawings, or the directions or position relationships in which the product of the present application is usually placed, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular direction, be constructed and operated in a particular direction, and therefore cannot be understood as limiting the present application.

[0042] Example 1

[0043] As Figures 1 to 2As shown, this embodiment provides a method for pretreatment of wastewater from the concentration process of a natural gas acetylene unit, including the following steps:

[0044] S1. Wastewater from the concentration process enters the wastewater pretreatment tank. The wastewater pretreatment tank is equipped with an air stripping zone, an aeration zone, a phase separation zone, and a carbon black slurry collection zone. Wastewater from the concentration process is treated in stages in each zone of the wastewater pretreatment tank.

[0045] S2. The clear liquid at the bottom of the phase separation zone is pumped to the wastewater treatment unit by the wastewater pump, and the carbon black slurry in the carbon black slurry collection zone is pumped to the incineration unit for treatment by the carbon black slurry pump.

[0046] S3. The gas source for the airlift zone and aeration zone of the concentrated wastewater pretreatment tank is factory air with controllable flow. By controlling the flow rate of factory air, the composition of combustible gases in the gas discharged from the top of the pretreatment tank can be ensured to be far below their lower explosive limits. The top of the airlift zone is connected to the exhaust pipe, and the end of the exhaust pipe is divided into two paths. One path is connected to the incinerator through the combustion air pipeline, and the other path is connected to the water seal device through the water seal connecting pipe. Under normal operating conditions, the gas in the combustion air pipeline is sent to the incinerator for treatment as combustion air, and the calorific value of the waste gas is recovered and utilized while the harmful components in the gas are removed by combustion.

[0047] S4. When the incinerator is in abnormal operating condition, the switch valve on the combustion air pipeline is interlocked and cut off; the gas in the exhaust pipe is discharged to the activated carbon adsorption tower after breaking through the water seal of the water seal device through the water seal connecting pipe. After the activated carbon adsorption tower treats the gas to meet the standards, it is discharged to a safe place.

[0048] Example 2

[0049] like Figures 1 to 2 As shown, this embodiment provides a method for pretreatment of wastewater from the concentration process of a natural gas acetylene unit, including the following steps:

[0050] S1. Wastewater from the concentration process enters the wastewater pretreatment tank. The wastewater pretreatment tank is equipped with an air stripping zone, an aeration zone, a phase separation zone, and a carbon black slurry collection zone in sequence. The first aeration zone, the second aeration zone, the phase separation zone, and the carbon black slurry collection zone are separated by the first partition, the second partition, and the third partition in sequence. The wastewater from the concentration process is treated step by step in each zone of the wastewater pretreatment tank.

[0051] Step S11: After the wastewater from the concentration process enters from the top of the wastewater pretreatment tank, it comes into counter-current contact with the rising factory air in the air stripping area (random packing) through the distributor. Some of the dissolved gas is desorbed into the air stripping gas. The air stripping treatment can remove some of the dissolved waste gas from the wastewater.

[0052] In step S12, the wastewater after stripping flows into the first aeration area by gravity, and is subjected to preliminary aeration treatment by 30 groups of row-column distributed aeration nozzles arranged at the bottom of the area, so as to reduce the COD of the wastewater and further remove the dissolved combustible and toxic gases in the wastewater. The residence time of the wastewater in the area is designed to be 30 minutes. After the treatment, the amount of dissolved waste gas in the wastewater is substantially removed, and the COD value of the wastewater is reduced from the initial 1200 ppm to 600 ppm.

[0053] In step S13, the wastewater after the preliminary aeration treatment flows into the second aeration area through the openings arranged at the bottom of the first partition in the pretreatment tank, and is subjected to further aeration treatment by 60 groups of high-efficiency aeration nozzles arranged in a multi-layer annular distribution at the bottom of the area. The residence time of the wastewater in the area is designed to be 50 minutes. After the treatment, the COD value of the wastewater can be reduced to below 50 ppm.

[0054] In step S14, the wastewater after the two-stage aeration treatment overflows into the phase separation area through the second partition arranged in the pretreatment tank. The wastewater is allowed to stand in the phase separation area, and the carbon black in the wastewater is suspended on the water surface due to its small density. The height of the phase separation interface is controlled by the interface liquid level meter installed in the area.

[0055] In step S15, the carbon black slurry suspended on the liquid surface after the phase separation overflows into the carbon black slurry collection area through the third partition arranged in the pretreatment tank, so as to realize the liquid-solid separation of the wastewater.

[0056] S2, the clear liquid at the bottom of the phase separation area is pumped to the wastewater treatment device by the wastewater pump, and the carbon black slurry in the carbon black slurry collection area is pumped to the incineration unit for treatment by the carbon black slurry pump. The liquid level in the phase separation area is controlled by the liquid level regulating valve arranged on the outlet pipeline of the wastewater pump. Since the amount of carbon black entering the carbon black slurry collection area is not large, the carbon black slurry in the carbon black slurry collection area is manually opened at regular intervals to be pumped to the incineration unit for treatment. In this way, the waste solid and waste liquid are treated separately, and the heat value of the incinerated carbon black can be recovered to produce steam as a byproduct.

[0057] S3, the gas sources of the stripping area and the aeration area of the concentrated wastewater pretreatment tank are both controllable factory air. By controlling the gas volume of the factory air, it can be ensured that the combustible gas component in the gas discharged from the top of the pretreatment tank is far below the lower explosive limit. The top of the stripping area is connected with an exhaust pipeline, and the end of the exhaust pipeline is divided into two paths. One path is connected with the incinerator through a combustion air pipeline, and the other path is connected with a water seal device through a water seal communication pipe. Under normal conditions, the gas in the combustion air pipeline is sent to the incinerator as combustion air, so as to remove the harmful components in the exhaust gas and realize the recovery and utilization of the waste gas heat value.

[0058] S4, when the incinerator is in abnormal working condition, the switch valve on the combustion air pipeline is cut off; the gas in the exhaust pipe is discharged to the activated carbon adsorption tower after breaking the water seal of the water seal device through the water seal communication pipe, and the activated carbon adsorption tower is treated to reach the standard and then discharged to the safety place.

[0059] The scheme can effectively reduce the COD value of the concentrated wastewater of the acetylene device, realize liquid-solid phase separation treatment, avoid pollution of the environment and safety hazards caused by harmful gas resolution, and the like. The scheme is suitable for all natural gas acetylene devices. Meanwhile, the method can be used as a typical pretreatment method for wastewater containing solid and gas and having high COD, and has popularization value.

[0060] Embodiment 3

[0061] The embodiment provides a system for pretreating concentrated wastewater of a natural gas acetylene device, and is suitable for the method for pretreating concentrated wastewater of the natural gas acetylene device in the embodiment 1 or the embodiment 2.

[0062] The system comprises a concentrated wastewater inlet pipe, a concentrated wastewater pretreatment tank, a carbon black slurry pump, a wastewater pump, a burning unit, a wastewater treatment device, a factory air source, an incinerator, a water seal device and an activated carbon adsorption tower.

[0063] The concentrated wastewater pretreatment tank comprises a horizontal cavity and a vertical cavity which are in communication with each other, the vertical cavity is sequentially provided with a distributor and a gas stripping area from top to bottom, the horizontal cavity is sequentially provided with a first aeration area, a second aeration area, a phase separation area and a carbon black slurry collection area, and the first aeration area, the second aeration area, the phase separation area and the carbon black slurry collection area are separated by a first partition plate, a second partition plate and a third partition plate in sequence.

[0064] The concentrated wastewater inlet pipe is communicated to the distributor;

[0065] The phase separation area at the bottom is communicated to the wastewater treatment device through the wastewater pump and a pipeline, and the carbon black slurry in the carbon black slurry collection area is communicated to the burning unit through the carbon black slurry pump and a pipeline;

[0066] The factory air source is communicated to the first aeration area, the second aeration area and the gas stripping area through pipelines provided with flow control valves.

[0067] The top of the vertical cavity is communicated through an exhaust pipeline, the exhaust pipeline is divided into two routes at the end, one pipeline is communicated to the incinerator through a combustion air pipeline, and the other pipeline is communicated to the water seal device through a water seal communication pipeline, and the water seal device is communicated to the activated carbon adsorption tower.

[0068] A stop valve is arranged on the combustion air pipeline; the first aeration area at the bottom is provided with an aeration nozzle, and the second aeration area at the bottom is provided with a high-efficiency aeration nozzle.

Claims

1. A method for the pretreatment of wastewater from the concentration process of a natural gas acetylene plant, characterized in that, The method comprises the following steps: S1, the concentrated wastewater in the concentration process enters a concentrated wastewater pretreatment tank, a gas stripping area, an aeration area, a phase separation area and a carbon black slurry collection area are sequentially arranged in the concentrated wastewater pretreatment tank, and the concentrated wastewater in the concentration process is disposed in the areas of the concentrated wastewater pretreatment tank; the aeration area is divided into a first aeration area and a second aeration area; the first aeration area, the second aeration area, the phase separation area and the carbon black slurry collection area are sequentially separated by a first partition, a second partition and a third partition; and the detailed process of step S1 is as follows: In step S11, the concentrated wastewater in the concentration process enters the top of the concentrated wastewater pretreatment tank, and then is in reverse contact with the rising plant air through a distributor in the gas stripping area, wherein part of the dissolved gas is resolved into the gas stripping gas; The gas stripping treatment can remove part of the dissolved waste gas in the wastewater; In step S12, the wastewater after the gas stripping gravitates into the first aeration area, and the wastewater is subjected to preliminary aeration treatment through an aeration nozzle arranged at the bottom of the area, so that the COD of the wastewater is reduced and the combustible and toxic gas dissolved in the wastewater is further removed, the amount of the dissolved waste gas in the wastewater after the treatment is substantially removed, and the COD value of the wastewater is reduced from the initial value; In step S13, the wastewater after the preliminary aeration treatment flows to the second aeration area through the bottom opening of the first partition arranged in the pretreatment tank, and the wastewater is subjected to further aeration treatment through a high-efficiency aeration nozzle arranged at the bottom of the area, so that the COD value of the wastewater is further reduced; In step S14, the wastewater after the two-stage aeration treatment overflows to the phase separation area through the second partition arranged in the pretreatment tank, and the wastewater is subjected to phase separation by standing in the phase separation area, the carbon black in the wastewater is suspended on the water surface due to the small density, and the height of the phase separation interface is controlled by an interface liquid level meter arranged in the area; In step S15, the carbon black slurry suspended on the liquid surface after the phase separation overflows to the carbon black slurry collection area through the third partition arranged in the pretreatment tank, so that the liquid-solid separation of the wastewater is realized; In S2, the clear liquid at the bottom of the phase separation area is pumped to a wastewater treatment device by a wastewater pump, and the carbon black slurry in the carbon black slurry collection area is pumped to a burning unit by a carbon black slurry pump for treatment; In S3, the gas sources of the gas stripping area and the aeration area of the concentrated wastewater pretreatment tank are both controllable plant air, and the amount of the combustible gas in the gas discharged from the top of the pretreatment tank can be ensured to be far below the lower limit of the explosion limit by controlling the amount of the plant air; the top of the gas stripping area is communicated with an exhaust pipeline, the exhaust pipeline is divided into two routes at the end, one pipeline is communicated with a burning furnace through a combustion air pipeline, and the other pipeline is communicated with a water seal device through a water seal communication pipeline; under normal conditions, the gas in the combustion air pipeline is sent to the burning furnace as combustion air for treatment; In S4, when the burning furnace is in an abnormal condition, an on-off valve on the combustion air pipeline is interlocked and cut off; the gas in the exhaust pipeline is discharged to an activated carbon adsorption tower after breaking through the water seal of the water seal device, and is discharged to a safe place after treatment by the activated carbon adsorption tower.

2. The method of claim 1, wherein the method is characterized by: In step S12, the wastewater after gas stripping flows into the first aeration area by gravity, and is subjected to preliminary aeration treatment by 30 groups of row-column distributed aeration nozzles arranged at the bottom of the area, so as to reduce the COD of the wastewater and further remove the dissolved combustible and toxic gases in the wastewater. The residence time of the wastewater in the area is designed to be 30 minutes. After the treatment, the amount of dissolved waste gas in the wastewater is substantially removed, and the COD value of the wastewater is reduced from the initial 1200 ppm to 600 ppm.

3. The method of claim 1, wherein the method is characterized by: In step S13, the wastewater after the preliminary aeration treatment flows into the second aeration area through the openings arranged at the bottom of the first partition in the pretreatment tank, and is subjected to further aeration treatment by 60 groups of high-efficiency aeration nozzles arranged in multiple layers in the form of a ring at the bottom of the area. The residence time of the wastewater in the area is designed to be 50 minutes. After the treatment, the COD value of the wastewater can be reduced to below 50 ppm.

4. The method of claim 1, wherein the method is characterized by, In step S2, the liquid level in the phase separation area is controlled by the liquid level regulating valve arranged on the outlet pipeline of the wastewater pump.

5. The method of claim 1, wherein the method is characterized by: In step S2, since the amount of carbon black entering the carbon black slurry collection area is small, the carbon black slurry in the carbon black slurry collection area is manually opened at regular intervals to pump the carbon black slurry to the incineration unit for treatment. In this way, waste solid and waste liquid can be treated separately, and the heat value of the carbon black incineration can be recovered to produce steam as a byproduct.

6. A system for the pretreatment of wastewater from a natural gas acetylene plant concentration process, characterized in that, The method is suitable for the wastewater pretreatment of a natural gas acetylene device concentration process, and comprises a concentration process wastewater inlet pipe, a concentration wastewater pretreatment tank, a carbon black slurry pump, a wastewater pump, an incineration unit, a wastewater treatment device, a plant air source, an incinerator, a water seal device, and an activated carbon adsorption tower. The concentration wastewater pretreatment tank comprises a horizontal cavity and a vertical cavity that are in communication with each other. The vertical cavity is sequentially provided with a distributor and a gas stripping area from top to bottom. The horizontal cavity is sequentially provided with a first aeration area, a second aeration area, a phase separation area, and a carbon black slurry collection area. The first aeration area, the second aeration area, the phase separation area, and the carbon black slurry collection area are sequentially separated by a first partition, a second partition, and a third partition. The concentration process wastewater inlet pipe is connected to the distributor. The bottom of the phase separation area is connected to the wastewater treatment device through a wastewater pump and a pipeline. The carbon black slurry in the carbon black slurry collection area is connected to the incineration unit through a carbon black slurry pump and a pipeline. The plant air source is connected to the first aeration area, the second aeration area, and the gas stripping area through pipelines with flow control valves, respectively. The top of the vertical cavity is connected through an exhaust pipeline. The exhaust pipeline is divided into two routes. One pipeline is connected to the incinerator through a combustion air pipeline. The other pipeline is connected to the water seal device through a water seal connection pipeline. The water seal device is connected to the activated carbon adsorption tower.

7. A system for the pre-treatment of wastewater from a natural gas acetylene plant concentration process according to claim 6, characterized in that, An interlocking switch valve is arranged on the combustion air pipeline. Aeration nozzles are arranged at the bottom of the first aeration area. High-efficiency aeration nozzles are arranged at the bottom of the second aeration area.

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