POSM device wastewater treatment device and use method thereof

Abstract

The invention relates to the technical field of POSM device wastewater treatment, and particularly discloses a POSM device wastewater treatment device and a use method thereof.The POSM device wastewater treatment device comprises an ethylbenzene absorption tower and a storage tank, and the ethylbenzene absorption tower is connected with the storage tank through a first acid wastewater conveying pipe; a feeding tank pump, a heat exchanger first temperature detection meter and a second adjusting valve are mounted on the first acid wastewater conveying pipe; through a series of precautionary measures, the probability of peroxide decomposition in the acidic water pipeline and the acidic water tank is reduced, meanwhile, the content of oxygen generated by peroxide decomposition is continuously monitored, and accumulated oxygen is controlled within a safe range. The three feeding modes are flexibly switched, stable operation and safe production of the device are ensured, and meanwhile energy consumption of the device is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of POSM device wastewater treatment, in particular to a POSM device wastewater treatment device and a use method thereof. Background Art

[0002] Propylene oxide is an important organic chemical raw material in my country's chemical production. At the same time, my country is also the world's largest producer of propylene oxide, with a global production capacity of 30%. With increasingly stringent environmental regulations and increasingly severe penalties, the chlorohydrin method is facing the pressure of elimination. Due to the high investment, complex process and strong dependence on raw material resources of the co-oxidation process, large energy and chemical companies such as Sinopec and CNOOC have successively intervened through joint ventures, leading to the rapid upgrading of the domestic propylene oxide industry. In addition, the expansion of my country's PO market demand has greatly promoted the growth of my country's PO production capacity. The PO / SM method co-produces styrene, and the main raw materials are ethylene, benzene, propylene, etc., including peroxidation, epoxidation, propylene oxide refining, ethylbenzene recovery, acetophenone hydrogenation, methylbenzyl alcohol dehydration process, and styrene refining process. Acidic wastewater is generated in the ethylbenzene recovery system of the peroxidation unit, with a COD of 70,000 to 80,000 mg / L, and containing 8 to 10% formic acid, acetic acid, and propionic acid. To treat the acidic substances generated by the system, a commonly used method at home and abroad is to rely on a PO / SM device waste alkali solution treatment device, and the method mainly involves directly incinerating the generated acidic water at about 1,100°C, and using this method to treat the acidic substances generated by the system; the waste liquid generated by the device is stored in the early stage and sent to the downstream for treatment at a stable flow rate; the acidic water generated by the peroxidation unit may contain peroxides, and these peroxides will decompose and release heat and oxygen when the temperature exceeds 30°C. The accumulation of oxygen may form an explosive atmosphere, posing a production safety hazard. For this purpose, a POSM device wastewater treatment device and a use method thereof are provided. Summary of the invention

[0003] The purpose of the present invention is to provide a POSM device wastewater treatment device and a method of using the same in order to solve the problems raised by the above-mentioned background technology in view of the defects of the prior art.

[0004] To achieve the above object, the present invention provides the following technical solution: a POSM device wastewater treatment device, comprising an ethylbenzene absorption tower and a storage tank, wherein the ethylbenzene absorption tower is connected to the storage tank through a first acidic wastewater delivery pipe, and a feed tank pump, a first temperature detection meter of a heat exchanger, and a second regulating valve are installed on the first acidic wastewater delivery pipe;

[0005] The bottom of the storage tank is connected to a second acidic wastewater delivery pipe, a storage tank pump is installed on the second acidic wastewater delivery pipe, the second acidic wastewater delivery pipe is connected to a third acidic wastewater delivery pipe, a first regulating valve is installed on the third acidic wastewater delivery pipe, the first acidic wastewater delivery pipe and the third acidic wastewater delivery pipe are connected through a pipeline, and valves are installed on the first acidic wastewater delivery pipe, the third acidic wastewater delivery pipe and the connected pipelines to form an acidic water treatment switching system;

[0006] The top of the storage tank is provided with a storage tank pressure detection and control system, a nitrogen pressure replenishment pipeline and a nitrogen pressure relief pipeline, and one end of the nitrogen pressure relief pipeline is connected to an activated carbon adsorption system;

[0007] The storage tank is provided with a cooling coil inside, and an online oxygen analyzer and a second temperature detection meter are also installed on the storage tank.

[0008] As a preferred technical solution of the present invention, a pressure boosting valve is installed on the nitrogen pressure boosting pipeline, a pressure relief valve is installed on the nitrogen pressure relief pipeline, and a nitrogen replenishing system is also connected to the nitrogen pressure boosting pipeline.

[0009] As a preferred technical solution of the present invention, the pressure-boosting valve and the pressure-releasing valve are both solenoid valves, and the storage tank pressure detection and control system includes a pressure sensor and a controller A, the controller A is electrically connected to the pressure-boosting valve and the pressure-releasing valve, respectively, and the pressure sensor is installed inside the storage tank.

[0010] As a preferred technical solution of the present invention, an electromagnetic valve is installed on the pipeline of the nitrogen replenishment system, and the online oxygen analyzer is used to monitor the oxygen content generated by the decomposition of peroxide in the storage tank. The online oxygen analyzer is connected to the nitrogen replenishment system through a control system.

[0011] As a preferred technical solution of the present invention, the second regulating valve is a solenoid valve, and the second regulating valve is connected to a liquid level control system. The liquid level control system includes a liquid level sensor and a controller B. The controller B is electrically connected to the second regulating valve and is used to control the switch of the second regulating valve. The liquid level sensor is installed inside the ethylbenzene absorption tower.

[0012] As a preferred technical solution of the present invention, the first regulating valve is a solenoid valve, and the first regulating valve is connected to a flow control system, and the flow control system includes a flow meter and a controller C. The flow meter is installed on the third acidic wastewater conveying pipe and is used to detect the acidic wastewater flow in the third acidic wastewater conveying pipe. The controller C is electrically connected to the first regulating valve and is used to control the switch of the first regulating valve.

[0013] As a preferred technical solution of the present invention, the heat exchanger, the cooling water outlet pipe, the cooling water inlet pipe, and the first temperature detection meter constitute a cooling system. The heat exchanger is provided with a heat exchange tube inside, the cooling water outlet pipe is arranged at the outlet of the heat exchange tube, the cooling water inlet pipe is arranged at the inlet of the heat exchange tube, and the first temperature detection meter is arranged at the outlet of the heat exchanger for detecting the temperature of the wastewater after passing through the cooling system.

[0014] As a preferred technical solution of the present invention, the water inlet of the cooling coil is connected to the cooling water input pipe, and the water outlet of the cooling coil is connected to the cooling water output pipe.

[0015] A method for using a POSM device wastewater treatment device, the specific steps are as follows:

[0016] Step 1: The acidic water in the ethylbenzene absorption tower is transported to the heat exchanger through the feed tank pump on the first acidic wastewater delivery pipe to cool the acidic water;

[0017] Step 2: The temperature of the cooled acidic water is monitored by a first temperature detection meter. When the temperature of the acidic water is cooled to 35°C or below, the acidic water is sent to a downstream storage tank or directly sent to a waste liquid treatment system through an acidic water treatment switching system;

[0018] Step 3: A storage tank pressure detection and control system is designed on the storage tank. Nitrogen is replenished through the nitrogen pressure replenishment pipeline, and nitrogen is discharged to the atmosphere through the nitrogen pressure relief pipeline to maintain the pressure in the storage tank at 5-15KaG. The nitrogen replenished by the nitrogen pressure replenishment pipeline dilutes the oxygen concentration.

[0019] Step 4: The amount of oxygen generated by the decomposition of peroxide in the storage tank is monitored by an online oxygen analyzer, and a high interlock of oxygen content is designed. When the oxygen content value reaches 8%, the high interlock of oxygen content is activated, and the solenoid valve in the nitrogen replenishment system at the top of the storage tank will open to continuously purge nitrogen;

[0020] Step 5: The second temperature detector on the storage tank will monitor the temperature inside the storage tank, and use the cooling coil to cool down the heat generated by the decomposition of peroxide in the storage tank in time to keep the material in the tank below 35°C;

[0021] Step 6: The acidic water in the storage tank is transported to the downstream waste liquid treatment system through the storage tank pump. When the downstream waste liquid treatment system is abnormal and cannot fully receive all the acidic water, part of the acidic water is directly transported to the downstream waste liquid treatment system, and part of the acidic water is sent to the storage tank.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention reduces the probability of peroxide decomposition in the acidic water pipeline and the acidic water tank through a series of preventive measures, while continuously monitoring the oxygen content generated by the decomposition of peroxide and controlling the accumulated oxygen within a safe range.

[0024] The present invention adopts three feeding methods: the first is to feed the material into the storage tank first and then feed it downstream; the second is not to feed the material into the storage tank, but directly feed it to the downstream waste liquid treatment; the third is to adjust the flow rate to the storage tank and the flow rate of the downstream waste liquid, so that part of it goes to the waste liquid treatment and part of it goes to the storage tank. The three feeds can be adjusted according to the downstream load. The three feeding methods adopted by the present invention can be flexibly switched to ensure the stable operation and safe production of the device while reducing the energy consumption of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of the present invention.

[0026] In the figure: 1-ethylbenzene absorption tower; 2-feeding tank pump; 3-heat exchanger; 301-cooling water outlet pipe; 302-cooling water inlet pipe; 303-first temperature detection meter; 4-flow control system; 401-first regulating valve; 5-liquid level control system; 501-second regulating valve; 6-storage tank; 7-online oxygen analyzer; 8-activated carbon adsorption system; 9-storage tank pressure detection and control system; 901-nitrogen pressure replenishing pipeline; 902-nitrogen pressure relief pipeline; 10-storage tank pump; 11-nitrogen replenishing system; 12-acidic water treatment switching system; 13-second acidic wastewater delivery pipe; 14-second temperature detection meter; 15-cooling coil; 16-first acidic wastewater delivery pipe; 17-third acidic wastewater delivery pipe. DETAILED DESCRIPTION

[0027] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0028] Example: See Figure 1 The present invention provides a technical solution: a POSM device wastewater treatment device, comprising an ethylbenzene absorption tower 1 and a storage tank 6, the ethylbenzene absorption tower 1 is connected to the storage tank 6 through a first acid wastewater delivery pipe 16, and a feed tank pump 2, a heat exchanger 3, a first temperature detection meter 303, and a second regulating valve 501 are installed on the first acid wastewater delivery pipe 16;

[0029] The bottom of the storage tank 6 is connected to a second acidic wastewater delivery pipe 13, on which a storage tank pump 10 is installed, and the second acidic wastewater delivery pipe 13 is connected to a third acidic wastewater delivery pipe 17, on which a first regulating valve 401 is installed, and the first acidic wastewater delivery pipe 16 and the third acidic wastewater delivery pipe 17 are connected through a pipeline, and valves are installed on the first acidic wastewater delivery pipe 16, the third acidic wastewater delivery pipe 17 and the connected pipelines to form an acidic water treatment switching system 12, and the acidic water treatment switching system 12 can realize flexible switching of acidic wastewater delivery;

[0030] The top of the storage tank 6 is provided with a storage tank pressure detection and control system 9, a nitrogen pressure-compensating pipeline 901 and a nitrogen pressure-relieving pipeline 902. One end of the nitrogen pressure-relieving pipeline 902 is connected to an activated carbon adsorption system 8, which is used for adsorption treatment by the activated carbon adsorption system 8 and then discharged into the atmosphere to avoid polluting the atmosphere.

[0031] A cooling coil 15 is provided inside the storage tank 6 , and an online oxygen analyzer 7 and a second temperature detection meter 14 are also installed on the storage tank 6 . The online oxygen analyzer 7 can monitor the oxygen concentration in the storage tank 6 in real time.

[0032] A pressure boosting valve is installed on the nitrogen pressure boosting pipeline 901 , a pressure relief valve is installed on the nitrogen pressure relief pipeline 902 , and a nitrogen replenishing system 11 is also connected to the nitrogen pressure boosting pipeline 901 , and the storage tank 6 can be purged using the nitrogen replenishing system 11 .

[0033] Both the pressure-boosting valve and the pressure-releasing valve are solenoid valves. The storage tank pressure detection and control system 9 includes a pressure sensor and a controller A. The controller A is electrically connected to the pressure-boosting valve and the pressure-releasing valve, respectively. The pressure sensor is installed inside the storage tank 6. The pressure sensor is used to detect the pressure inside the storage tank 6, and the pressure inside the storage tank 6 is regulated by controlling the pressure-boosting valve and the pressure-releasing valve.

[0034] An electromagnetic valve is installed on the pipeline of the nitrogen replenishment system 11. The online oxygen analyzer 7 is used to monitor the oxygen content generated by the decomposition of peroxide in the storage tank 6. The online oxygen analyzer 7 is connected to the nitrogen replenishment system 11 through a control system.

[0035] The second regulating valve 501 is a solenoid valve, which is connected to the liquid level control system 5. The liquid level control system 5 includes a liquid level sensor and a controller B. The controller B is electrically connected to the second regulating valve 501 and is used to control the switch of the second regulating valve 501. The liquid level sensor is installed inside the ethylbenzene absorption tower 1 to detect the liquid level inside the ethylbenzene absorption tower 1, thereby controlling the switch size of the second regulating valve 501.

[0036] The first regulating valve 401 is a solenoid valve, and the first regulating valve 401 is connected to the flow control system 4. The flow control system 4 includes a flow meter and a controller C. The flow meter is installed on the third acidic wastewater conveying pipe 17 and is used to detect the acidic wastewater flow in the third acidic wastewater conveying pipe 17. The controller C is electrically connected to the first regulating valve 401 and is used to control the switch of the first regulating valve 401. The first regulating valve 401 can be used to adjust the acidic wastewater flow.

[0037] The heat exchanger 3, the cooling water outlet pipe 301, the cooling water inlet pipe 302, and the first temperature detector 303 constitute a cooling system. The heat exchanger 3 is provided with a heat exchange pipe inside. The cooling water outlet pipe 301 is arranged at the outlet of the heat exchange pipe, the cooling water inlet pipe 302 is arranged at the inlet of the heat exchange pipe, and the first temperature detector 303 is arranged at the outlet of the heat exchanger 3 for detecting the temperature of the waste water after passing through the cooling system to ensure that the temperature of the acidic water sent to the storage tank 6 is lower than 35°C.

[0038] The water inlet of the cooling coil 15 is connected to the cooling water input pipe, and the water outlet of the cooling coil 15 is connected to the cooling water output pipe. The cooling coil 15 replaces the heat in the storage tank 6 by means of the coolant.

[0039] A method for using a POSM device wastewater treatment device, the specific steps are as follows:

[0040] Step 1: The acidic water in the ethylbenzene absorption tower 1 is transported to the heat exchanger 3 through the feed tank pump 2 on the first acidic wastewater transport pipe 16 to cool the acidic water;

[0041] Step 2: The temperature of the cooled acidic water is monitored by the first temperature detection meter 303. When the temperature of the acidic water is cooled to 35°C or below, the acidic water is sent to the downstream storage tank 6 or directly sent to the waste liquid treatment system through the acidic water treatment switching system 12;

[0042] Step 3: A storage tank pressure detection and control system 9 is designed on the storage tank 6. Nitrogen is replenished through the nitrogen pressure replenishment pipeline 901, and nitrogen is discharged to the atmosphere through the nitrogen pressure relief pipeline 902 to maintain the pressure in the storage tank 6 at 5-15KaG. The nitrogen replenished by the nitrogen pressure replenishment pipeline 901 dilutes the oxygen concentration.

[0043] Step 4: The amount of oxygen generated by the decomposition of the peroxide in the storage tank 6 is monitored by an online oxygen analyzer 7, and a high interlock of the oxygen content is designed. When the oxygen content value reaches 8%, the high interlock of the oxygen content is activated, and the solenoid valve in the nitrogen replenishment system 11 at the top of the storage tank 6 is opened to continuously purge nitrogen;

[0044] Step 5: The second temperature detection meter 14 on the storage tank 6 monitors the temperature in the storage tank 6, and uses the cooling coil 15 to cool down the heat generated by the decomposition of the peroxide in the storage tank 6 in time to keep the material in the tank below 35°C;

[0045] Step 6: The acidic water in the storage tank 6 is transported to the downstream waste liquid treatment system through the storage tank pump 10. When the downstream waste liquid treatment system is abnormal and cannot completely receive all the acidic water, part of the acidic water is directly transported to the downstream waste liquid treatment system, and part of the acidic water is sent to the storage tank 6.

[0046] Working principle: After the acidic wastewater is extracted from the ethylbenzene absorption tower 1, it is sent to the cooling system through the feed pump 2 to ensure that the temperature of the acidic water sent to the storage tank 6 is lower than 35°C. The cooling system is a heat exchanger 3 using cooling water as the cooling medium. There is a temperature display at the outlet of the heat exchanger 3 to detect the temperature of the acidic water in the feeding pipeline in real time to ensure that the material reaches the temperature required by the process after being cooled by the heat exchanger 3. The liquid level in the ethylbenzene absorption tower and the feeding amount of the acidic wastewater can be controlled by the liquid level control system 5. If the liquid level in the tower is low, the second regulating valve 501 is closed, and if the liquid level in the tower is high, the second regulating valve 501 is opened. The cooled acidic water can be sent to the storage tank 6 through the acidic water treatment switching system 12, or it can be directly sent to the downstream waste liquid treatment system for incineration or incineration after the waste alkali is concentrated. The two-line switching process ensures the shortest distance and reduces the risk of pipeline residues.

[0047] When the acidic water is selected to go directly to the waste liquid treatment system, in order to ensure the stable operation of the downstream waste liquid treatment system, the downstream feed amount of the acidic water needs to be controlled by the flow control system 4.

[0048] When acidic water is selected to be sent to the storage tank 6, the storage tank 6 is stored in the form of nitrogen sealing, and the nitrogen sealing adopts split-range control. When the pressure is too low, the pressure relief valve on the nitrogen pressure relief pipeline 902 is closed, and the pressure relief valve on the nitrogen pressure boosting pipeline 901 is opened for pressure boosting; when the pressure is too high, the pressure boosting valve on the nitrogen pressure boosting pipeline 901 is closed, and the pressure relief valve on the nitrogen pressure relief pipeline 902 is opened for pressure relief. The gas in the storage tank 6 is adsorbed by the activated carbon adsorption system 8 and then discharged to the atmosphere. The nitrogen supplemented by the split-range control also plays a role in diluting the oxygen concentration. In order to reduce the probability of peroxide decomposition in the acidic wastewater during storage, the storage tank is added with a second temperature detection meter 14 and a cooling coil 15. Once the heat generated by the decomposition of peroxide in the tank is generated, the cooling coil 15 can be cooled in time. In addition, an online oxygen analyzer 7 is added to continuously monitor the oxygen content generated by the decomposition of peroxide and control the accumulated oxygen within a safe range. At the same time, a high interlock of oxygen content is designed. When the oxygen content reaches the interlock value, the nitrogen replenishment system 11 on the tank top is opened to continuously perform nitrogen purge. The acidic water in the storage tank 6 is sent to the downstream waste liquid treatment system through the storage tank pump 10.

[0049] When the downstream waste liquid treatment system is abnormal and cannot completely receive all the acidic water, part of the acidic water can be taken to go directly to the waste liquid treatment system, and part of the acidic water can be sent to the storage tank 6.

[0050] Usage: The flow rate of acidic wastewater generated by the ethylbenzene absorption tower is about 10t / h, and the temperature is 60℃; the acidic water contains about 2wt% of acidic substances and 6wt% of peroxides. In order to avoid acid corrosion of the pipeline, the pipelines and storage tanks containing acidic water are all made of stainless steel. The acidic water in the ethylbenzene absorption tower is cooled by the heat exchanger 3 at the outlet of the feed tank pump 2. The temperature of the cooled acidic water is monitored by the first temperature detection meter 303 at the outlet of the cooler. When the temperature of the acidic water is cooled to 35℃ or below, it is sent to the downstream storage tank or directly to the waste liquid treatment system.

[0051] The top of the storage tank 6 is designed with a pressure split-range control. By adding nitrogen and discharging it to the atmosphere, the pressure in the tank is maintained at a stable level of 5 to 15 KaG. The nitrogen added by the split-range control also plays a role in diluting the oxygen concentration. In order to monitor the amount of oxygen produced by the decomposition of peroxides in the acidic water tank and avoid the accumulation of oxygen to form an explosive mixed gas, an online oxygen analyzer 7 is designed on the top of the storage tank 6 to monitor the amount of oxygen in the tank in real time, and a high interlock for the oxygen content is designed. When the oxygen content reaches 8%, the high interlock for the oxygen content is activated, and the nitrogen valve of the nitrogen replenishment system on the top of the tank will open to continuously purge nitrogen.

[0052] Storage tank 6 is a dome tank, and a circulating water coil is designed inside the tank to timely cool down the heat generated by the decomposition of peroxide in the tank and keep the material in the tank below 35°C.

[0053] Process design management: Acidic wastewater is treated by switching between two routes. In order to reduce the risk of peroxide retention and decomposition in storage tank 6, a bypass route is added near both sides of storage tank 6 (the distance between isolation valves is the shortest). Under the condition of meeting normal production, the acidic water is directly sent to the incinerator for treatment. In order to meet the pressure requirements for sending to the incinerator, the feed tank pump needs to meet the pipeline pressure of not less than 1.2MPaG for transporting acidic wastewater to the boundary of the incinerator.

[0054] Optimization of heating method: The heating method of acid water pipelines has been optimized to electric heating to maintain the temperature inside the pipeline at 15-20℃ to avoid freezing of acid water pipes when parking in winter.

[0055] The above embodiments only express the implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention.

Claims

1. A POSM wastewater treatment device, comprising an ethylbenzene absorption tower (1) and a storage tank (6), characterized in that: The ethylbenzene absorption tower (1) is connected to the storage tank (6) via a first acidic wastewater delivery pipe (16), and the first acidic wastewater delivery pipe (16) is equipped with a feed tank pump (2), a heat exchanger (3), a first temperature detection meter (303) and a second regulating valve (501); The bottom of the storage tank (6) is connected to a second acidic wastewater delivery pipe (13), a storage tank pump (10) is installed on the second acidic wastewater delivery pipe (13), a third acidic wastewater delivery pipe (17) is connected to the second acidic wastewater delivery pipe (13), a first regulating valve (401) is installed on the third acidic wastewater delivery pipe (17), the first acidic wastewater delivery pipe (16) and the third acidic wastewater delivery pipe (17) are connected through a pipeline, and valves are installed on the first acidic wastewater delivery pipe (16), the third acidic wastewater delivery pipe (17) and the connected pipelines to form an acidic water treatment switching system (12); The top of the storage tank (6) is provided with a storage tank pressure detection and control system (9), a nitrogen pressure replenishing pipeline (901) and a nitrogen pressure relief pipeline (902), and one end of the nitrogen pressure relief pipeline (902) is connected to an activated carbon adsorption system (8); A cooling coil (15) is arranged inside the storage tank (6), and an online oxygen analyzer (7) and a second temperature detection meter (14) are also installed on the storage tank (6).

2. The POSM device wastewater treatment plant according to claim 1, characterized in that: The nitrogen pressure-compensating pipeline (901) is provided with a pressure-compensating valve, the nitrogen pressure-relieving pipeline (902) is provided with a pressure-relieving valve, and the nitrogen pressure-compensating pipeline (901) is also connected to a nitrogen replenishing system (11).

3. The POSM device wastewater treatment plant according to claim 2, characterized in that: The pressure-compensating valve and the pressure-releasing valve are both solenoid valves. The storage tank pressure detection and control system (9) comprises a pressure sensor and a controller A. The controller A is electrically connected to the pressure-compensating valve and the pressure-releasing valve, respectively. The pressure sensor is installed inside the storage tank (6).

4. The POSM device wastewater treatment plant according to claim 2, characterized in that: An electromagnetic valve is installed on the pipeline of the nitrogen replenishment system (11), and the online oxygen analyzer (7) is used to monitor the oxygen content generated by the decomposition of peroxide in the storage tank (6). The online oxygen analyzer (7) is connected to the nitrogen replenishment system (11) through a control system.

5. The POSM device wastewater treatment device according to claim 1, characterized in that: The second regulating valve (501) is a solenoid valve. The second regulating valve (501) is connected to a liquid level control system (5). The liquid level control system (5) comprises a liquid level sensor and a controller B. The controller B is electrically connected to the second regulating valve (501) and is used to control the switch of the second regulating valve (501). The liquid level sensor is installed inside the ethylbenzene absorption tower (1).

6. The POSM device wastewater treatment device according to claim 1, characterized in that: The first regulating valve (401) is a solenoid valve. The first regulating valve (401) is connected to a flow control system (4). The flow control system (4) comprises a flow meter and a controller C. The flow meter is installed on the third acidic wastewater conveying pipe (17) and is used to detect the flow rate of acidic wastewater in the third acidic wastewater conveying pipe (17). The controller C is electrically connected to the first regulating valve (401) and is used to control the switch of the first regulating valve (401).

7. The POSM device wastewater treatment device according to claim 1, characterized in that: The heat exchanger (3), the cooling water outlet pipe (301), the cooling water inlet pipe (302), and the first temperature detector (303) constitute a cooling system. The heat exchanger (3) is provided with a heat exchange pipe inside. The cooling water outlet pipe (301) is arranged at the outlet of the heat exchange pipe, the cooling water inlet pipe (302) is arranged at the inlet of the heat exchange pipe, and the first temperature detector (303) is arranged at the outlet of the heat exchanger (3) for detecting the temperature of the wastewater after passing through the cooling system.

8. The POSM device wastewater treatment device according to claim 1, characterized in that: The water inlet of the cooling coil (15) is connected to the cooling water input pipe, and the water outlet of the cooling coil (15) is connected to the cooling water output pipe.

9. A method for using the POSM device wastewater treatment device according to any one of claims 1 to 8, characterized in that: The specific steps are as follows: Step 1: The acidic water in the ethylbenzene absorption tower (1) is transported to the heat exchanger (3) via the feed tank pump (2) on the first acidic wastewater transport pipe (16), and the acidic water is cooled; Step 2: The temperature of the cooled acidic water is monitored by a first temperature detection meter (303). When the temperature of the acidic water is cooled to 35°C or below, the acidic water is sent to a downstream storage tank (6) or directly sent to a waste liquid treatment system through an acidic water treatment switching system (12); Step 3: A storage tank pressure detection and control system (9) is designed on the storage tank (6), nitrogen is replenished through the nitrogen pressure replenishing pipeline (901), and nitrogen is discharged to the atmosphere through the nitrogen pressure relief pipeline (902), so as to maintain the pressure in the storage tank (6) at 5-15 KaG. The nitrogen replenished by the nitrogen pressure replenishing pipeline (901) dilutes the oxygen concentration; Step 4: The amount of oxygen generated by the decomposition of the peroxide in the storage tank (6) is monitored by an online oxygen analyzer (7), and a high interlock of the oxygen content is designed. When the oxygen content value reaches 8%, the high interlock of the oxygen content is activated, and the solenoid valve in the nitrogen replenishment system (11) at the top of the storage tank (6) is opened to continuously purge nitrogen; Step 5: The second temperature detection meter (14) on the storage tank (6) monitors the temperature in the storage tank (6), and uses the cooling coil (15) to promptly cool down the heat generated by the decomposition of the peroxide in the storage tank (6), so as to keep the material in the tank below 35°C; Step 6: The acidic water in the storage tank (6) is transported to the downstream waste liquid treatment system through the storage tank pump (10). When the downstream waste liquid treatment system is abnormal and cannot completely receive all the acidic water, part of the acidic water is directly transported to the downstream waste liquid treatment system, and part of the acidic water is sent to the storage tank (6).

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