Petrochemical sewage denitrification skid-mounted system

Abstract

The utility model provides a petrochemical sewage denitrification skid-mounted system which comprises a deep treatment tank which is sequentially divided into a filter tank, an equipment area and a combined tank, wherein a water inlet of the whole system is formed in the combined tank, a water inlet is formed in the bottom of the filter tank, and a water outlet is formed in the top of the filter tank; a heterotrophic denitrification filter tank and a sulfur autotrophic denitrification filter tank are arranged in the filter tank, and the sulfur autotrophic denitrification filter tank is arranged below the heterotrophic denitrification filter tank; a working condition switching system is arranged in the equipment area, comprises a parallel pipeline and a series pipeline, and is used for controlling the operation mode between the heterotrophic denitrification filter tank and the sulfur autotrophic denitrification filter tank. Petrochemical sewage is filtered through the advanced treatment tank, and two operation conditions are flexibly switched, so that the capacity of the system for coping with water quality and water volume fluctuation can be improved while the petrochemical sewage is denitrified well.

Description

Technical Field

[0001] This utility model belongs to the field of wastewater purification technology and relates to a skid-mounted system for denitrification of petrochemical wastewater. Background Technology

[0002] Currently, deep denitrification of wastewater in the petrochemical industry mainly employs either autotrophic denitrification or heterotrophic denitrification processes. Autotrophic denitrification filters utilize sulfur-based autotrophic filter media, requiring replenishment based on media consumption rates. Heterotrophic denitrification necessitates the addition of carbon sources to maintain microbial growth. Both processes, when used alone, are poorly suited to handling fluctuations in influent water quality. For example, if the influent C / N ratio is high, heterotrophic and autotrophic bacteria coexist, preventing autotrophic bacteria from becoming the dominant species. Conversely, if the influent C / N ratio is low, large amounts of carbon sources are required to maintain heterotrophic bacteria growth, which can easily lead to increased effluent COD. Furthermore, current denitrification filters are mostly constructed of concrete, lacking mobility and flexibility, making them unsuitable for handling fluctuations in water volume.

[0003] In view of the above, this utility model is hereby proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a skid-mounted system for denitrifying petrochemical wastewater. This system uses a deep treatment tank to denitrify and filter petrochemical wastewater, and can flexibly switch between two operating conditions. It can effectively denitrify petrochemical wastewater while improving the system's ability to cope with fluctuations in water quality and quantity.

[0005] In order to achieve the above-mentioned objectives of this utility model, the following technical solution is adopted:

[0006] A skid-mounted system for denitrification of petrochemical wastewater includes a deep treatment tank, which is sequentially divided into a filter tank, an equipment area, and a combined tank. The combined tank is equipped with an inlet for the entire system, the filter tank has an inlet at its bottom and an outlet at its top. The filter tank contains a heterotrophic denitrification filter and a sulfur autotrophic denitrification filter, with the sulfur autotrophic denitrification filter positioned below the heterotrophic denitrification filter. The equipment area includes a mode switching system comprising parallel and series pipes for controlling the operating modes of the heterotrophic denitrification filter and the sulfur autotrophic denitrification filter.

[0007] This invention primarily utilizes a deep treatment tank to denitrify and filter wastewater generated in the petrochemical industry. The deep treatment tank is divided into a filter, an equipment area, and a combined tank. To address the problem of excessive organic matter addition caused by the use of heterotrophic denitrification filters in existing technologies, this invention employs a working condition switching system to flexibly switch between two working conditions. This allows for effective wastewater purification while simultaneously resolving the issue of excessive organic matter caused by the use of heterotrophic denitrification filters.

[0008] Preferably, as a further feasible option, the height of the filter tank is 1m-1.5m higher than the height of the equipment area and the combined tank.

[0009] In this invention, the advanced treatment tank is divided into a filter tank, an equipment area, and a combined tank. The height of the filter tank is crucial because chemical wastewater first enters the advanced treatment tank through the inlet on the combined tank. After preliminary treatment in the combined tank, the chemical wastewater is introduced into the filter tank. The water that has undergone denitrification filtration in the filter tank flows by gravity into the intermediate tank due to the height difference between the filter tank, the intermediate tank, and the combined tank. Therefore, in this invention, when the height of the filter tank is 1m-1.5m higher than the heights of the intermediate tank and the combined tank, the advanced treatment tank achieves excellent denitrification effect on the chemical wastewater.

[0010] Preferably, as a further feasible option, the heterotrophic denitrification filter and the sulfur autotrophic denitrification filter are configured from top to bottom as a clear water layer, a packing layer, a support layer, and a water and air distribution layer; wherein each of the water and air distribution layers is provided with a water inlet, each of the clear water layers is provided with a water inlet and an air inlet, and the water and air distribution layer in the sulfur autotrophic denitrification filter is also provided with an air inlet; the clear water layer is sequentially divided into a wastewater tank and a clear water tank.

[0011] Preferably, as a further feasible option, a backwash fan, an internal circulation pump, and an aeration fan are arranged vertically in sequence within the equipment area, wherein the backwash fan is connected to the clear water layer of the filter; the internal circulation pump is connected to both the heterotrophic denitrification filter and the sulfur autotrophic denitrification filter; and the aeration fan is connected to the air inlet of the sulfur autotrophic denitrification filter. The internal circulation pump can effectively increase the flow rate of wastewater between the filters, thereby accelerating their denitrification efficiency.

[0012] Preferably, as a further feasible option, the combined pool is divided into a stripping pool, an intermediate water pool, and a clear water pool; the stripping pool is located above the intermediate water pool.

[0013] Preferably, as a further feasible option, the operating condition switching system is located on one side of the backwash blower, and two water inlet pumps are also provided above the operating condition switching system. The two sides of the water inlet pumps are respectively connected to the stripping tank and the heterotrophic denitrification filter, and the heterotrophic denitrification filter is also connected to the clear water tank.

[0014] Preferably, as a further feasible option, the series pipeline includes a series control valve and an intermediate water pump connected sequentially along the water inlet direction, one end of the series control valve being connected to the intermediate water tank; the intermediate water pump is provided with an inlet end and an outlet end on both sides, wherein the inlet end is connected to the series control valve, and the outlet end is connected to the sulfur autotrophic denitrification filter.

[0015] The parallel pipeline includes a parallel control valve and an intermediate water pump connected sequentially along the water inlet direction, and the parallel control valve is connected to the water inlet pump.

[0016] Preferably, as a further feasible option, a backwash water pump is also provided below the operating condition switching system, and the clear water tank is connected to the water inlet of the water distribution and air distribution layer through the backwash water pump.

[0017] The wastewater treatment process in this invention is mainly divided into two operating conditions. When the deep treatment tank is in series operation, the series pipeline in the operating condition switching system is open and the parallel pipeline is closed. That is, the parallel control valve connected to the intermediate water pump is closed, and the series control valve connected to the intermediate water pump is open. At this time, the entire deep treatment tank is in series operation. The chemical wastewater first flows into the combined tank through the inlet of the stripping tank set in the combined tank. The chemical wastewater undergoes preliminary treatment in the stripping tank. Nitrogen is used in the stripping tank... The process involves stripping oxygen from the chemical wastewater, reducing its oxygen content. The wastewater is then pumped from the stripping tank into the filter bed through the inlet at the bottom. It then flows through the water and air distribution layer of the heterotrophic denitrification filter. In the heterotrophic denitrification filter, the wastewater flows upwards through the water and air distribution layer, the support layer, and the packing layer, before concentrating in the clear water layer. Two inlet pumps are used, one as a backup, ensuring that the deep treatment process continues even if the active pump fails. In the normal operation of the denitrification tank, after the wastewater undergoes denitrification through the heterotrophic microorganisms in the heterotrophic denitrification filter, the denitrified wastewater will spontaneously flow into the intermediate water tank due to the height difference between the filter, the combined tank, and the equipment area. At this time, the series control valves open and the parallel control valves close, and the intermediate water pump draws wastewater from the intermediate water tank and introduces it into the sulfur autotrophic denitrification filter. The main purpose of introducing the denitrified water into the sulfur autotrophic denitrification filter is to remove excess chemicals added in the heterotrophic denitrification filter. The purpose of this invention is not to remove nitrogen, but to increase the oxygen content in the water. Therefore, in order to increase the oxygen content in the water, this invention uses an aeration blower connected to the water distribution and air distribution layer of the sulfur autotrophic denitrification filter to aerate the water, thereby increasing the oxygen content in the water. After aeration by the aeration blower, the water undergoes organic matter removal in the sulfur autotrophic denitrification filter, thereby removing the excess reagent added to the heterotrophic denitrification filter. After the wastewater is finally treated by the sulfur autotrophic denitrification filter, the water will flow into the clear water tank by gravity, and then the treated wastewater will be discharged.

[0018] When the advanced treatment tanks are operating in parallel, the parallel pipelines in the operating condition switching system are open, while the series pipelines are closed. Specifically, the parallel control valve connected to the inlet pump is open, and the series control valve connected to the intermediate tank is closed. At this time, the entire advanced treatment tank is operating in parallel. The chemical wastewater first flows into the combined tank through the inlet of the stripping tank, where it undergoes preliminary treatment. In the stripping tank, nitrogen is used to strip oxygen from the chemical wastewater, reducing its oxygen content. Then, the wastewater is pumped from the top of the operating condition switching system... Simultaneously, as wastewater from the stripping tank is introduced into the heterotrophic denitrification filter through the water and air distribution layer, the intermediate water pump connected to the inlet pump directly draws pretreated chemical wastewater from the stripping tank through the water and air distribution layer at the bottom of the autotrophic denitrification filter, achieving simultaneous denitrification in both the autotrophic and heterotrophic denitrification filters. Subsequently, the wastewater treated by the filter will flow by gravity into the clear water tank in the combined tank due to the height difference between the filter, the intermediate water tank, and the combined tank, thus discharging the treated chemical wastewater.

[0019] Based on this, the present invention further cleans the sulfur autotrophic denitrification filter and heterotrophic denitrification filter in the filter bed by setting up a backwash fan and a back-suction pump to work together, so as to avoid the denitrification effect of the deep treatment tank being affected by impurities clogging the packing layer. The specific process is that the backwash pump connected to the clear water tank draws water out of the clear water tank and mixes it with the gas introduced by the backwash fan through the water distribution and gas distribution layer of the sulfur autotrophic denitrification filter and the heterotrophic denitrification filter, and then introduces it into the filter bed to wash the filter bed from bottom to top. Since the baffle of the clear water tank is higher than the baffle of the wastewater tank, the wastewater after washing will be discharged from the wastewater tank.

[0020] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0021] (1) This utility model provides a skid-mounted system for denitrification of petrochemical wastewater, which denitrifies and filters petrochemical wastewater through a deep treatment tank, and can flexibly switch between two operating conditions, which can effectively denitrify petrochemical wastewater while improving the system's ability to cope with fluctuations in water quality and quantity. Attached Figure Description

[0022] Figure 1 This is a plan view of a skid-mounted system for denitrification of petrochemical wastewater according to this utility model;

[0023] Figure 2 This is a structural diagram of a sulfur autotrophic denitrification filter and a heterotrophic denitrification filter in a skid-mounted system for denitrification of petrochemical wastewater according to the present invention.

[0024] Figure 3This is a schematic diagram of the operating condition switching system in a skid-mounted system for denitrification of petrochemical wastewater according to this utility model.

[0025] The labels in the attached diagram represent: 1. Deep treatment tank; 2. Filter tank; 3. Equipment area; 4. Combined tank; 5. Heterotrophic denitrification filter; 6. Sulfate autotrophic denitrification filter; 7. Intermediate water tank; 8. Stripping tank; 9. Clear water tank; 10. Inlet pump; 11. Intermediate water pump; 12. Internal circulation pump; 13. Backwash blower; 14. Aeration blower; 15. Backwash water pump; 16. Water and air distribution layer; 17. Support layer; 18. Packing layer; 19. Clear water layer; 20. Clear water tank; 21. Wastewater tank; 22. Series control valve; 23. Parallel control valve. Detailed Implementation

[0026] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of this utility model, but not all embodiments, and are only used to illustrate this utility model, and should not be regarded as limiting the scope of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0027] In the description of this utility model, it should be understood that the terms "top", "bottom", "inner", "side wall", etc., which indicate orientation or positional relationship, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0028] To more clearly illustrate the technical solution of this utility model, the following description is provided in the form of specific embodiments.

[0029] Example 1

[0030] See Figure 1-3 This utility model relates to a denitrification system for petrochemical wastewater, comprising: 1. a deep treatment tank; 2. a filter tank; 3. an equipment area; 4. a combined tank; 5. a heterotrophic denitrification filter; 6. a sulfur autotrophic denitrification filter; 7. an intermediate water tank; 8. a stripping tank; 9. a clear water tank; 10. an inlet pump; 11. an intermediate water pump; 12. an internal circulation pump; 13. a backwash blower; 14. an aeration blower; 15. a backwash water pump; 16. a water and air distribution layer; 17. a support layer; 18. a packing layer; 19. a clear water layer; 20. a clear water tank; and 21. a wastewater tank.

[0031] See Figure 1As can be seen, the petrochemical wastewater denitrification skid-mounted system of this utility model mainly includes a deep treatment tank 1, which is divided into a filter tank 2, an equipment area 3 and a combined tank 4. The combined tank 4 is provided with the water inlet of the whole system, the bottom of the filter tank 2 is provided with the water inlet, and the top of the filter tank 2 is provided with the water outlet.

[0032] The filter tank 2 is equipped with a heterotrophic denitrification filter 5 and a sulfur autotrophic denitrification filter 6, with the sulfur autotrophic denitrification filter 6 located below the heterotrophic denitrification filter 5; the equipment area 3 is equipped with an operating condition switching system, which includes parallel and series pipes for controlling the operation mode between the heterotrophic denitrification filter and the sulfur autotrophic denitrification filter; the height of the filter tank 2 is 1m-1.5m higher than the height of the equipment area 3 and the combined tank 4;

[0033] Depend on Figure 2 It can be seen that the heterotrophic denitrification filter 5 and the sulfur autotrophic denitrification filter 6 of this utility model are arranged from top to bottom as a clear water layer 19, a packing layer 18, a support layer 17 and a water and air distribution layer 16; wherein the water and air distribution layer 16 of both the sulfur autotrophic denitrification filter 6 and the heterotrophic denitrification filter 5 are provided with a water inlet and an air inlet; the clear water layer of both is divided into a wastewater tank and a clear water tank in sequence;

[0034] Depend on Figure 1 It can be seen that a backwash fan 13, an internal circulation pump 12 and an aeration fan 14 are arranged in sequence along the vertical direction on the left side of the equipment area 3. The backwash fan 13 and the internal circulation pump 12 are connected to the heterotrophic denitrification filter 5 and the sulfur autotrophic denitrification filter 6. The aeration fan 14 is connected to the air inlet provided on the water distribution and air distribution layer 16 of the sulfur autotrophic denitrification filter 6.

[0035] The combined tank 4 is divided into a stripping tank 8, an intermediate water tank 7, and a clear water tank 9, with the stripping tank 8 located above the intermediate water tank 7;

[0036] The operating condition switching system located outside the filter is located on one side of the backwash blower 13. The inlet pump 10 is located above the operating condition switching system. One side of the inlet pump 10 is connected to the stripping tank 8, and the other side is connected to the heterotrophic denitrification filter 5.

[0037] The working condition switching system of this utility model is mainly divided into series pipelines and parallel pipelines. The series pipeline includes a series control valve 23 and an intermediate water pump 11 connected in sequence along the water inlet direction. The series control valve 23 is connected to the stripping tank 8. The intermediate water pump 11 has an inlet end and an outlet end at both ends. The inlet end of the intermediate water pump is connected to the series control valve 23, and the outlet end is connected to the sulfur autotrophic denitrification filter 6.

[0038] The parallel pipeline mainly includes a parallel control valve 22 and an intermediate water pump 11 connected in sequence along the water inlet direction. The parallel control valve 22 is also connected to the water inlet pump 10.

[0039] Depend on Figure 1 It can be seen that the backwash water pump 15 is located below the working condition switching, and one end of the backwash water pump 15 is connected to the clear water tank 9, while the other end is connected to the water and air distribution layers of the sulfur autotrophic denitrification filter 6 and the heterotrophic denitrification filter 5, respectively.

[0040] See Figure 3 When the system in this invention is in series operation, its specific water purification and denitrification process is as follows:

[0041] Petrochemical wastewater first flows into the combined tank 4 through the inlet on the stripping tank 8 for pretreatment. Nitrogen is used in the stripping tank 8 to reduce the oxygen content of the wastewater. The pretreated wastewater then flows out of the stripping tank 8 and is pumped out by the inlet pump 10. It then passes through the water distribution and air distribution layer 16 in the heterotrophic denitrification filter 5 and is introduced into the filter. After initial denitrification by heterotrophic microorganisms in the filter 5, preliminary denitrification occurs. At this point, the parallel pipeline in the operating condition switching system is closed, and the series pipeline is opened. Specifically, the parallel control valve 23 connected to the intermediate water pump 11 is closed, and the series control valve 22 connected to the intermediate water pump 11 is opened. The entire deep treatment tank is now in series operation, resulting in the denitrified effluent flowing between the filter 2, equipment area 3, and combined tank 4. Due to the height difference, the water in filter 2 can flow by gravity to the intermediate water tank 7. Then, the intermediate water pump 11 will pump the denitrified water from the intermediate water tank 11 and introduce it into the sulfur autotrophic denitrification filter 6 through the water distribution and aeration layer 16. At this time, the denitrified water is introduced into the sulfur autotrophic denitrification filter 6 mainly to remove the excess reagents added in the heterotrophic denitrification filter 5, rather than to achieve the purpose of denitrification. Therefore, in order to increase the oxygen content in the water, this invention uses an aeration blower 14 connected to the water distribution and aeration layer 16 of the sulfur autotrophic denitrification filter 6 to aerate the water, thereby increasing the oxygen content in the water. After aeration by the aeration blower 14, the water undergoes organic matter removal in the sulfur autotrophic denitrification filter 6. After the removal is completed, the water flows by gravity to the clear water tank 9 for discharge due to the height difference.

[0042] When the system of this invention is in parallel operation, its specific water purification and denitrification process is as follows:

[0043] Petrochemical wastewater first flows into the combined tank 4 through the inlet of the stripping tank 8 for pretreatment. In the stripping tank 8, nitrogen is used to reduce the oxygen content of the wastewater. The pretreated wastewater then flows out of the stripping tank 8 and is pumped out by the inlet pump 10. It then passes through the water distribution and air distribution layer 16 in the heterotrophic denitrification filter 5 and undergoes preliminary denitrification via heterotrophic microorganisms. At this point, due to the switching operation, the parallel pipes in the system open and the series pipes close. When the series control valve 22 connected to the intermediate water pump 11 is closed, the parallel control valve 23 connected to the intermediate water pump 11 is opened. At this time, the entire deep treatment tank 1 is in parallel operation. At this time, the intermediate water pump 11 will also pump water from the stripping tank 8 and introduce it into the sulfur autotrophic denitrification filter 6 through the water distribution and air distribution layer 16 of the sulfur autotrophic denitrification filter 6 for denitrification. Therefore, through the parallel pipeline, the sulfur autotrophic denitrification filter 6 and the heterotrophic denitrification filter 5 simultaneously denitrify the petrochemical wastewater. After the denitrification is completed, the water will flow by gravity to the clear water tank 9 for discharge due to the height difference.

[0044] Meanwhile, this utility model also uses a backwash water pump 15 and a backwash blower 13 to clean the filter bed using an air-washing-air-water combined flushing-water washing method, to avoid impurities clogging the packing layer and thus affecting the denitrification effect of the filter bed on petrochemical wastewater. The specific backwashing process is as follows:

[0045] The backwash water pump 15, connected to the clear water tank 9, draws out the water from the clear water tank 9 and mixes it with the gas introduced by the backwash blower 13. The mixture is then introduced into the filter tank through the water and gas distribution layer 19 of the sulfur autotrophic denitrification filter tank 6 and the heterotrophic denitrification filter tank 5, and the filter tank is washed from bottom to top. Since the baffle of the clear water tank 20 is higher than the baffle of the wastewater tank 21, the wastewater after washing will be discharged from the wastewater tank 21.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A skid-mounted system for denitrification of petrochemical wastewater, characterized in that, The system includes a deep treatment tank, which is sequentially divided into a filter tank, an equipment area, and a combined tank. The combined tank has an inlet for the entire system, the filter tank has an inlet at the bottom and an outlet at the top. The filter tank contains a heterotrophic denitrification filter and a sulfur autotrophic denitrification filter, with the sulfur autotrophic denitrification filter positioned below the heterotrophic denitrification filter. The equipment area includes a mode switching system, comprising parallel and series pipes, used to control the operating modes of the heterotrophic and sulfur autotrophic denitrification filters.

2. The skid-mounted system for denitrification of petrochemical wastewater according to claim 1, characterized in that, The height of the filter tank is 1m-1.5m higher than the height of the equipment area and the combined tank.

3. The skid-mounted system for denitrification of petrochemical wastewater according to claim 1, characterized in that, The heterotrophic denitrification filter and the sulfur autotrophic denitrification filter are arranged from top to bottom as a clear water layer, a packing layer, a support layer, and a water and air distribution layer; wherein each water and air distribution layer is provided with a water inlet, each clear water layer is provided with a water inlet and an air inlet, and the water and air distribution layer in the sulfur autotrophic denitrification filter is also provided with an air inlet; the clear water layer is divided into a wastewater tank and a clear water tank.

4. The skid-mounted system for denitrification of petrochemical wastewater according to claim 3, characterized in that, The equipment area is arranged vertically in sequence with a backwash fan, an internal circulation pump, and an aeration fan, wherein the backwash fan is connected to the clear water layer of the filter; the internal circulation pump is connected to both the heterotrophic denitrification filter and the sulfur autotrophic denitrification filter; and the aeration fan is connected to the air inlet of the sulfur autotrophic denitrification filter.

5. The skid-mounted system for denitrification of petrochemical wastewater according to claim 4, characterized in that, The combined pool is divided into a stripping pool, an intermediate water pool, and a clear water pool; the stripping pool is located above the intermediate water pool.

6. The skid-mounted system for denitrification of petrochemical wastewater according to claim 5, characterized in that, The operating condition switching system is located on one side of the backwash blower. Two water inlet pumps are also installed above the operating condition switching system. The two sides of the water inlet pumps are connected to the stripping tank and the heterotrophic denitrification filter, respectively. The heterotrophic denitrification filter is also connected to the clear water tank.

7. The skid-mounted system for denitrification of petrochemical wastewater according to claim 6, characterized in that, The series pipeline includes a series control valve and an intermediate water pump connected sequentially along the water inlet direction. One end of the series control valve is connected to the intermediate water tank. The intermediate water pump has an inlet end and an outlet end on both sides, wherein the inlet end is connected to the series control valve and the outlet end is connected to the sulfur autotrophic denitrification filter. The parallel pipeline includes a parallel control valve and an intermediate water pump connected sequentially along the water inlet direction, and the parallel control valve is connected to the water inlet pump.

8. The skid-mounted system for denitrification of petrochemical wastewater according to claim 6, characterized in that, A backwash water pump is also installed below the operating condition switching system, and the clear water tank is connected to the water inlet of the water distribution and air distribution layer through the backwash water pump.

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