Heterogeneous ozone advanced oxidation integrated treatment device and process for sulfur-containing sewage

Abstract

The invention relates to the technical field of gas field sulfur-containing sewage treatment, and discloses a heterogeneous ozone advanced oxidation integrated treatment device and process for sulfur-containing sewage. A structural form of a sewage buffer tank and an ozone oxidation reactor is adopted, and the sewage buffer tank is utilized to gentle liquid level fluctuation in the tank, so that the relative stability of the liquid inlet amount of a subsequent process is ensured; the sewage in the sewage buffer tank is conveyed into the ozone oxidation reactor by the sewage lifting pump, and the sulfur-containing sewage and ozone are subjected to advanced oxidation reaction under the action of the catalyst, so that sulfur ions in the sulfur-containing sewage can be quickly oxidized into SO2-ions, and the purposes of purifying the sewage and eliminating peculiar smell are achieved. Due to the adoption of the selenium-rich catalyst, long-term use can be realized by one-time addition; secondly, under the action of a selenium-rich catalyst, ozone is catalyzed to generate. OH (hydroxyl radical), the oxidation capacity is extremely high, no selectivity exists, sulfide in sewage and ozone are promoted to be subjected to advanced oxidation, oxidation is more thorough, and the ozone utilization rate is higher; and finally, the equipment investment is small, and the occupied area is small.

Description

Technical Field

[0001] The invention relates to the technical field of gas field sulfur-containing wastewater treatment, and in particular to a device and process for heterogeneous ozone advanced oxidation integrated treatment of sulfur-containing wastewater. Background Art

[0002] During the development and production of sulfur-containing gas fields, a large amount of sulfur-containing wastewater will be generated, causing surrounding soil pollution and pipeline corrosion. At the same time, the H2S gas flashed in the wastewater will cause human harm and environmental pollution. Therefore, sulfur-containing wastewater cannot be discharged directly, and the sulfide needs to be treated to meet the standards for discharge or reinjection. At present, there are many methods for treating sulfur-containing wastewater, such as air oxidation, chemical precipitation and gas stripping. The air oxidation method has a good treatment effect, but it requires high temperature and high pressure working conditions, large energy consumption, and high construction investment and operating costs. The chemical precipitation method is to add ferrous or ferric salts to the wastewater to generate insoluble substances for removal, but when the sulfur content in the wastewater is high, the system produces a large amount of mud and the treatment cost is high. The gas stripping method is to reduce the partial pressure of H2S in the gas stripping tower by countercurrent contact between the gas stripping gas and the wastewater in the gas stripping tower, accelerate the desorption of H2S in the wastewater, and achieve the purpose of desulfurization. This method is greatly affected by pressure, pH value, and gas-liquid mass transfer. The desulfurization effect is poor when the pH value of the sulfur-containing wastewater is high. Summary of the invention

[0003] In view of the above-mentioned defects in the prior art, a device and process for the integrated treatment of sulfur-containing wastewater by heterogeneous ozone advanced oxidation is provided, which is suitable for the desulfurization treatment of sulfur-containing produced water from sulfur-containing gas fields and can solve the problems of high energy consumption of the device, high investment and operating costs, and poor desulfurization effect.

[0004] The technical solution adopted by the present invention to solve the above technical problems is:

[0005] A device for the integrated treatment of sulfur-containing wastewater by heterogeneous ozone advanced oxidation, characterized in that it includes a sewage buffer tank connected to an external sulfur-containing sewage pipeline, an ozone oxidation reactor connected to the sewage buffer tank through a pipeline, and an exhaust gas processor and an ozone generator connected to the ozone oxidation reactor; the ozone oxidation reactor is connected to an external drainage pipeline, and a selenium-rich catalyst is arranged inside the ozone oxidation reactor; a sewage lifting pump is arranged between the pipelines between the ozone oxidation reactor and the sewage buffer tank.

[0006] According to the above technical scheme, the connection between the exhaust gas treatment device and the ozone oxidation reactor is located at the top of the ozone oxidation reactor; the connection between the external drainage pipe and the ozone oxidation reactor is located at the upper part of the side wall of the ozone oxidation reactor, and the connection between the external drainage pipe and the ozone oxidation reactor is lower than the connection between the exhaust gas treatment device and the ozone oxidation reactor; the connection between the ozone generator and the ozone oxidation reactor, and the connection between the sewage buffer tank and the ozone oxidation reactor are all located at the lower part of the side wall of the ozone oxidation reactor.

[0007] According to the above technical scheme, the ozone oxidation reactor includes a tank body and a catalyst filler located in the tank body, the catalyst filler is located in the middle of the tank body and divides the tank body into an upper and lower space; an ozone exhaust gas outlet connected to the exhaust gas processor is provided at the top of the tank body, a liquid discharge port is provided on the side of the upper space, a sewage discharge port is provided at the bottom of the tank body, a sewage liquid inlet and an ozone inlet are provided on the side wall of the lower space, and the ozone inlet adopts a lotus-shaped structure, and a plurality of upward-facing air holes are provided at intervals on the lotus-shaped structure.

[0008] According to the above technical solution, the selenium-rich catalyst uses aluminum and titanium oxide as carriers to load selenium, and the catalyst adopts a spherical structure.

[0009] According to the above technical solution, sewage discharge pipelines are provided at the bottom of the sewage buffer tank and the ozone oxidation generator.

[0010] According to the above technical solution, a sewage flow meter is provided on the pipeline between the sewage buffer tank and the ozone oxidation reactor, and an ozone flow meter is provided on the pipeline between the ozone generator and the ozone oxidation reactor.

[0011] A heterogeneous ozone advanced oxidation treatment process for sulfur-containing wastewater, characterized in that: the pH value of the sulfur-containing wastewater is adjusted to control the pH value to 8.0-10.0; then the sulfur-containing wastewater and ozone are simultaneously charged into a tank containing a selenium-rich catalyst to carry out an advanced oxidation-reduction reaction, and the sulfur-containing wastewater is treated with ozone according to the sulfur content of the wastewater. 2- The concentration of ozone is adjusted; during this process, the liquid inlet pressure is maintained at 0.1Mpa~0.2MPa, and the selenium-rich catalyst is used to catalyze ozone to produce hydroxyl radicals, thereby achieving the goal of reducing S in sewage to 2- Oxidized to SO 2- .

[0012] According to the above technical scheme, according to the S of sulfur-containing wastewater in the gas field 2- The concentration and flow rate of ozone are controlled by controlling the amount of ozone produced so that the ozone concentration is maintained at 25mg / L~35mg / L; in addition to controlling the concentration of ozone introduced, the flow rate of sewage and ozone entering the tank is controlled according to the sewage flow meter and ozone flow meter in the device, and the flow rate of S in the reaction tank is controlled. 2- and ozone content.

[0013] According to the above technical scheme, the optimal operating conditions of this process are that the pH of sulfur-containing wastewater is 9.0, the ozone concentration is 30 mg / L, and the liquid phase inlet pressure is 0.15 MPa.

[0014] The present invention has the following beneficial effects:

[0015] 1. The structure of sewage buffer tank + ozone oxidation reactor is adopted. The sewage buffer tank is used to smooth the liquid level fluctuation in the tank to ensure the relative stability of the liquid inflow in the subsequent process. The sewage in the sewage buffer tank is transported to the ozone oxidation reactor by the sewage lifting pump. The sulfur-containing sewage undergoes an advanced oxidation reaction with ozone under the action of the catalyst, which can quickly oxidize the sulfur ions in the sulfur-containing sewage into SO 2- Ions can purify sewage and eliminate odors; the purified sewage is discharged from the external drainage pipe connected to the ozone oxidation reactor; the tail gas emitted by the ozone oxidation reactor is ozone, which can be decomposed into oxygen and discharged into the atmosphere through the tail gas processor connected to the ozone oxidation generator, without pollution to the environment.

[0016] Based on the above measures, the sewage is connected to the integrated treatment device for heterogeneous advanced oxidation of sulfur-containing sewage of the present invention, and the selenium-rich catalyst and ozone in the ozone oxidation reactor are used to oxidize sulfur ions, thereby achieving the purpose of purifying sewage. Since the selenium-rich catalyst is used, it can be used for a long time after one addition, and can be replaced once every 3 to 5 years; secondly, under the action of the selenium-rich catalyst, ozone is catalyzed to produce ·OH (hydroxyl radical), which has extremely strong and non-selective oxidation ability, promoting the advanced oxidation of sulfide in sewage and ozone, and the oxidation is more thorough, and the ozone utilization rate is higher; finally, the equipment investment of the present invention is small and the floor space is small.

[0017] 2. The optimal working conditions of this process are that the pH of sulfur-containing wastewater is 9.0, the ozone concentration is 30 mg / L, and the liquid inlet pressure is 0.15 MPa. Based on this process, under the optimal working conditions, S 2- The removal rate can reach more than 99%, and the S in the treated sewage 2- When the concentration is below 0.5mg / L, the purification effect is significant. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of an embodiment provided by the present invention;

[0019] Figure 2 It is a structural schematic diagram of an ozone oxidation reactor provided in an embodiment of the present invention;

[0020] In the figure, 1. sulfur wastewater pipeline; 2. wastewater buffer tank; 3. ozone oxidation reactor; 3-1. tank body; 3-2. catalyst filler; 3-3. ozone tail gas outlet; 3-4. drain port; 3-5. sewage outlet; 3-6. sewage inlet; 3-7. ozone inlet; 4. exhaust gas processor; 5. ozone generator; 6. sewage lifting pump; 7. sewage pipeline; 8. sewage flow meter; 9. ozone flow meter. DETAILED DESCRIPTION

[0021] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0022] Reference Figures 1-2 As shown, the present invention provides an integrated device for treating sulfur-containing wastewater by heterogeneous ozone advanced oxidation.

[0023] Example 1

[0024] It includes a sewage buffer tank 2 connected to an external sulfur-containing sewage pipeline 1, an ozone oxidation reactor 3 connected to the sewage buffer tank through a pipeline, and an exhaust gas processor 4 and an ozone generator 5 connected to the ozone oxidation reactor; the ozone oxidation reactor is connected to an external drainage pipeline, and a selenium-rich catalyst is arranged inside the ozone oxidation reactor; a sewage lifting pump 6 is arranged between the pipeline between the ozone oxidation reactor and the sewage buffer tank.

[0025] In this embodiment, a sewage buffer tank + ozone oxidation reactor is used. The sewage buffer tank is used to smooth the liquid level fluctuation in the tank to ensure the relative stability of the liquid inlet amount in the subsequent process. The sewage in the sewage buffer tank is transported to the ozone oxidation reactor by a sewage lifting pump. The sulfur-containing sewage undergoes an advanced oxidation reaction with ozone under the action of a catalyst, which can quickly oxidize the sulfur ions in the sulfur-containing sewage into SO 2- ) ions to purify sewage and eliminate odor; the purified sewage is discharged from the external drainage pipe connected to the ozone oxidation reactor; the tail gas emitted by the ozone oxidation reactor is ozone, which can be decomposed into oxygen and discharged into the atmosphere through the tail gas processor connected to the ozone oxidation generator, without pollution to the environment.

[0026] Based on the above measures, the sewage is connected to the integrated treatment device for heterogeneous advanced oxidation of sulfur-containing sewage of the present invention, and the selenium-rich catalyst and ozone in the ozone oxidation reactor are used to oxidize sulfur ions, thereby achieving the purpose of purifying sewage. Since the selenium-rich catalyst is used, it can be used for a long time after one addition, and can be replaced once every 3 to 5 years; secondly, under the action of the selenium-rich catalyst, ozone is catalyzed to produce ·OH (hydroxyl radical), which has extremely strong and non-selective oxidation ability, promoting the advanced oxidation of sulfide in sewage and ozone, and the oxidation is more thorough, and the ozone utilization rate is higher; finally, the equipment investment of the present invention is small and the floor space is small.

[0027] Based on the above embodiments, a preferred arrangement of the treatment device is provided. Specifically, the connection between the tail gas processor and the ozone oxidation reactor is located at the top of the ozone oxidation reactor; the connection between the external drainage pipe and the ozone oxidation reactor is located at the upper part of the side wall of the ozone oxidation reactor, and the connection between the external drainage pipe and the ozone oxidation reactor is lower than the connection between the tail gas processor and the ozone oxidation reactor; the connection between the ozone generator and the ozone oxidation reactor, and the connection between the sewage buffer tank and the ozone oxidation reactor are all located at the lower part of the side wall of the ozone oxidation reactor.

[0028] In this embodiment, the height of the connection between the external drainage pipe and the ozone oxidation reactor inside the ozone oxidation reactor is the height inside the ozone oxidation reactor; the heights of the connection between the ozone generator and the sewage buffer tank and the ozone oxidation reactor are all below the liquid level, and the ozone entering from the ozone generator and the sulfur-containing sewage entering from the sewage buffer tank are in the area below the liquid level, and cooperate with the selenium-rich catalyst to cause advanced oxidation.

[0029] Example 2

[0030] The structure and principle of Example 2 are similar to those of Example 1, except that: the ozone oxidation reactor includes a tank body 3-1 and a catalyst filler 3-2 located in the tank body, the catalyst filler is located in the middle of the tank body, and divides the tank body into an upper and lower space; an ozone exhaust gas outlet 3-3 connected to the exhaust gas processor is provided on the top of the tank body, a liquid discharge port 3-4 is provided on the side of the upper space, a sewage discharge port 3-5 is provided on the bottom of the tank body, a sewage inlet 3-6 and an ozone inlet 3-7 are provided on the side wall of the lower space, and the ozone inlet adopts a lotus-shaped structure, and a plurality of upward-facing air holes are provided at intervals on the lotus-shaped structure.

[0031] In the structure of the ozone oxidation reactor described in this embodiment, the sulfur-containing sewage enters from the sewage inlet in the lower space and overflows the catalyst filler and is discharged from the drain port; the ozone generator enters the tank body through the ozone inlet, is evenly mixed into the sewage by the lotus-shaped structure and floats upward, and in this process, ozone is catalyzed by the catalyst filler to produce OH (hydroxyl radicals), which promotes the advanced oxidation of sulfides in the sewage and ozone, thereby achieving the purpose of purifying the sewage. In this process, the solid impurities remaining in the sewage are deposited at the bottom of the tank body and discharged from the sewage outlet, and the unreacted ozone enters the tail gas generator from the ozone tail gas outlet at the top of the tank body for treatment.

[0032] In the above-mentioned embodiments 1-2, preferably, the selenium-rich catalyst is a catalyst in which selenium is supported by aluminum or titanium oxide, and the catalyst has a spherical structure.

[0033] In the above-mentioned embodiments 1-2, the sulfur-containing wastewater entering from the external sulfur-containing wastewater pipeline contains solid impurities. In order to facilitate the discharge of the solid impurities, a sewage discharge pipeline 7 is provided at the bottom of the sewage buffer tank and the ozone oxidation generator.

[0034] Example 3

[0035] The structure and principle of Example 3 are similar to those of Example 1, except that: in order to facilitate intelligent management, a sewage flow meter 8 is provided on the pipeline between the sewage buffer tank and the ozone oxidation reactor to measure the sewage flow; an ozone flow meter 9 is provided on the pipeline between the ozone generator and the ozone oxidation reactor to measure the ozone flow. The amount of ozone generated is adjusted according to the sewage inflow and the sulfide content in the sewage, and the process has strong adaptability and a wide treatment range, thereby achieving the purpose of improving the degree of automation and reducing operating costs.

[0036] The present invention also provides a heterogeneous ozone advanced oxidation treatment process for sulfur-containing wastewater: adjusting the pH value of the sulfur-containing wastewater to control the pH value at 8.0-10.0; then simultaneously charging the sulfur-containing wastewater and ozone into a tank containing a selenium-rich catalyst to carry out an advanced oxidation-reduction reaction; 2- The concentration of ozone is adjusted; during this process, the liquid inlet pressure is maintained at 0.1Mpa~0.2MPa, and the selenium-rich catalyst is used to catalyze ozone to produce hydroxyl radicals, thereby achieving the goal of reducing S in sewage to 2- Oxidized to SO 2- .

[0037] Under the action of the selenium-rich catalyst, the selenium-rich catalyst catalyzes ozone to produce OH (hydroxyl radical), which has extremely strong and non-selective oxidation ability, prompting the sulfide in the sewage to undergo advanced oxidation with ozone, with more thorough oxidation and higher ozone utilization rate; the device has strong process adaptability and a wide treatment range; the equipment investment is small, the footprint is small, the degree of automation is high, and the operating cost is low.

[0038] In the above embodiment, according to the S of the gas field sulfur-containing wastewater 2- The concentration and flow rate of ozone are controlled by controlling the amount of ozone produced so that the ozone concentration is maintained at 25mg / L~35mg / L; in addition to controlling the concentration of ozone introduced, the flow rate of sewage and ozone entering the tank is controlled according to the sewage flow meter and ozone flow meter in the device, and the flow rate of S in the reaction tank is controlled. 2- and ozone content.

[0039] After a large number of experimental verifications, the optimal operating conditions of this process are that the pH of sulfur-containing wastewater is 9.0, the ozone concentration is 30 mg / L, and the liquid phase inlet pressure is 0.15 MPa.

[0040] Based on this process, under the optimal working conditions, S 2- The removal rate can reach more than 99%, and the S in the treated sewage 2- When the concentration is below 0.5mg / L, the purification effect is significant.

[0041] The above are only preferred embodiments of the present invention, and certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention still fall within the protection scope of the present invention.

Claims

1. A device for treating sulfur-containing wastewater by heterogeneous ozone advanced oxidation, characterized in that: It includes a sewage buffer tank connected to an external sulfur-containing sewage pipeline, an ozone oxidation reactor connected to the sewage buffer tank through a pipeline, and an exhaust gas processor and an ozone generator connected to the ozone oxidation reactor; the ozone oxidation reactor is connected to an external drainage pipeline, and a selenium-rich catalyst is arranged inside the ozone oxidation reactor; a sewage lifting pump is arranged between the pipelines between the ozone oxidation reactor and the sewage buffer tank.

2. The device for treating sulfur-containing wastewater by heterogeneous ozone advanced oxidation according to claim 1 is characterized in that: The connection between the exhaust gas processor and the ozone oxidation reactor is located at the top of the ozone oxidation reactor; the connection between the external drainage pipe and the ozone oxidation reactor is located at the upper part of the side wall of the ozone oxidation reactor, and the connection between the external drainage pipe and the ozone oxidation reactor is lower than the connection between the exhaust gas processor and the ozone oxidation reactor; the connection between the ozone generator and the ozone oxidation reactor, and the connection between the sewage buffer tank and the ozone oxidation reactor are all located at the lower part of the side wall of the ozone oxidation reactor.

3. The device for treating sulfur-containing wastewater by heterogeneous ozone advanced oxidation according to claim 1 or 2, characterized in that: The ozone oxidation reactor comprises a tank body and a catalyst filler located in the tank body. The catalyst filler is located in the middle of the tank body and divides the tank body into an upper and lower space. An ozone tail gas outlet connected to the tail gas processor is provided on the top of the tank body, a liquid discharge port is provided on the side of the upper space, a sewage discharge port is provided on the bottom of the tank body, and a sewage liquid inlet and an ozone inlet are provided on the side wall of the lower space. The ozone inlet adopts a lotus-shaped structure, and a plurality of upward-facing air holes are provided at intervals on the lotus-shaped structure.

4. The device for treating sulfur-containing wastewater by heterogeneous ozone advanced oxidation according to claim 1 is characterized in that: The selenium-rich catalyst uses aluminum and titanium oxide as carriers to load selenium, and the catalyst adopts a spherical structure.

5. The device for treating sulfur-containing wastewater by heterogeneous ozone advanced oxidation according to claim 1 is characterized in that: There are sewage discharge pipelines at the bottom of the sewage buffer tank and the ozone oxidation generator.

6. The device for treating sulfur-containing wastewater by heterogeneous ozone advanced oxidation according to claim 1 is characterized in that: A sewage flow meter is provided on the pipeline between the sewage buffer tank and the ozone oxidation reactor, and an ozone flow meter is provided on the pipeline between the ozone generator and the ozone oxidation reactor.

7. A heterogeneous ozone advanced oxidation process for treating sulfur-containing wastewater, characterized in that: Adjust the pH value of the sulfur-containing wastewater to control the pH value at 8.0-10.0; then, charge the sulfur-containing wastewater and ozone into a tank containing a selenium-rich catalyst to perform an advanced oxidation-reduction reaction. 2- The concentration of ozone is adjusted; during this process, the liquid inlet pressure is maintained at 0.1Mpa~0.2MPa, and the selenium-rich catalyst is used to catalyze ozone to produce hydroxyl radicals, thereby achieving the goal of reducing S in sewage to 2- Oxidized to SO 2- .

8. The heterogeneous ozone advanced oxidation process for treating sulfur-containing wastewater according to claim 1, characterized in that: According to the S 2- The concentration and flow rate of ozone are controlled by controlling the amount of ozone produced so that the ozone concentration is maintained at 25mg / L~35mg / L; in addition to controlling the concentration of ozone introduced, the flow rate of sewage and ozone entering the tank is controlled according to the sewage flow meter and ozone flow meter in the device, and the flow rate of S in the reaction tank is controlled. 2- and ozone content.

9. The heterogeneous ozone advanced oxidation process for treating sulfur-containing wastewater according to claim 1, characterized in that: The optimal operating conditions of this process are that the pH of sulfur-containing wastewater is 9.0, the ozone concentration is 30 mg / L, and the liquid phase inlet pressure is 0.15 MPa.

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