Defluorination system and use method

Abstract

The invention discloses a defluorination system and a use method, and relates to the technical field of environmental governance, the defluorination system comprises a water inlet pipe, a rapid reaction zone, a first agent automatic feeding point, a medium-speed reaction zone, a second agent automatic feeding point, a slow reaction zone, a third agent automatic feeding point, a flocculent precipitation zone, a clean water tank and a Plc control system, the rear part of the water inlet pipe is sequentially communicated with a rapid reaction zone, a medium-speed reaction zone, a slow reaction zone, a flocculent settling zone and a clean water tank, and the first chemical automatic feeding point is used for adding a first chemical into the rapid reaction zone; the second agent automatic feeding point is used for feeding a second agent into the medium-speed reaction area; the third agent automatic feeding point is used for feeding a third agent into the slow reaction area; the Plc control system is in signal connection with the first automatic medicament feeding point, the second automatic medicament feeding point and the third automatic medicament feeding point, the structure is simple, the use is convenient, the operation cost is effectively reduced, and the fluorine removal effect is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental governance, and in particular to a fluorine removal system and a use method thereof. Background Art

[0002] In recent years, the state and local governments have successively issued many laws and policies on environmental management and requirements. With the increasing attention paid by the state and local governments to environmental protection and the improvement of relevant environmental protection regulations, pollution control in steel enterprises has entered a new era - a new era of pollution control in accordance with the law and ultra-low emissions. Environmental protection has become a life-and-death crisis that all steel enterprises must face. The water quality of the company's total external drainage should at least meet the Class V standard of the "Surface Water Environmental Quality Standard" (GB3838-2002), and the fluoride index of external drainage should meet the fluoride standard limit of the Class V standard of the "Surface Water Environmental Quality Standard" (GB3838-2002), that is, fluoride ≤1.5mg / l. To achieve this goal, the original treatment facilities were upgraded and renovated, and a new defluorination system was built with a treatment scale of up to 1500m 3 / h, and it is the first to carry out large-scale deep defluorination among steel enterprises in the country. The main method adopted is chemical coagulation and sedimentation. Coagulant is added to fluoride-containing water to form flocs and adsorb fluoride ions, which are removed by precipitation and filtration. The main structure is a high-density sedimentation tank + V-type filter. During the commissioning and operation process, the fluoride effluent basically reached the requirement of ≤1.5mg / l, and the average was about 1.3mg / l. However, it still faces practical difficulties such as shortage of reagent research and development, weak reagent stability, relatively extensive reagent addition, and low efficiency of supporting precipitation process technology. In addition, when the quality and quantity of sewage fluctuate, the dosing metering pump is frequently adjusted manually, the actual dosage is sometimes more and sometimes less, and the pollutant removal effect is unstable. Summary of the invention

[0003] The purpose of the present invention is to provide a defluorination system and a method of use to solve the problems existing in the above-mentioned prior art. The system has a simple structure, is easy to use, effectively reduces operating costs, and effectively improves the defluorination effect.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The present invention provides a defluorination system, comprising: a water inlet pipe, a fast reaction zone, a first agent automatic delivery point, a medium-speed reaction zone, a second agent automatic delivery point, a slow reaction zone, a third agent automatic delivery point, a flocculation and sedimentation zone, a clear water tank and a PLC control system, wherein the fast reaction zone is connected to the water inlet pipe; the first agent automatic delivery point is arranged above the fast reaction zone to add the first agent to the fast reaction zone; the bottom of the medium-speed reaction zone is connected to the top of the fast reaction zone; the second agent automatic delivery point is arranged above the fast and medium-speed reaction zone to add the second agent to the medium-speed reaction zone; the bottom of the slow reaction zone is connected to the top of the medium-speed reaction zone; the third agent automatic delivery point is arranged above the fast and slow reaction zone to add the third agent to the slow reaction zone; the top of the flocculation and sedimentation zone is connected to the top of the slow reaction zone, and the top of the clear water tank is connected to the top of the flocculation and sedimentation zone; the PLC control system is signal-connected to the first agent automatic delivery point, the second agent automatic delivery point and the third agent automatic delivery point.

[0006] Preferably, it also includes a first sludge return pipeline and a lifting pump, one end of the first sludge return pipeline is connected to the bottom of the flocculation sedimentation zone, and the other end is connected to the bottom of the slow reaction zone, and the lifting pump is arranged on the first sludge return pipeline.

[0007] Preferably, it also includes a second sludge return pipeline and a control valve, one end of the second sludge return pipeline is connected to the first sludge return pipeline between the lifting pump and the slow reaction zone, the control valve is arranged on the second sludge return pipeline, and the other end is connected to the bottom of the fast reaction zone, the control valve is connected to the PLC control system signal and can adjust the amount of return sludge in the second sludge return pipeline.

[0008] Preferably, it also includes a fluoridation meter, a first pH meter and a second pH meter, the fluoridation meter is arranged in the water inlet pipe, the first pH meter is arranged in the rapid reaction zone, the second pH meter is arranged in the clear water tank, and the fluoridation meter, the first pH meter and the second pH meter are all connected to the PLC control system signal.

[0009] Preferably, it further comprises a first agitator, a second agitator and a third agitator, wherein the first agitator is arranged in the fast reaction zone, the second agitator is arranged in the medium-speed reaction zone, and the third agitator is arranged in the slow reaction zone.

[0010] The present invention also provides a method for using the defluorination system as described in any one of the above items, comprising the following steps:

[0011] Fluoride-containing wastewater enters the system through the water inlet pipe. At this time, the fluoride meter installed on the water inlet pipe monitors the fluoride content in the inlet water in real time and transmits the data to the PLC control system;

[0012] The PLC control system preliminarily determines the dosage of the first automatic agent delivery point, the second automatic agent delivery point and the third automatic agent delivery point according to the fluoride content data transmitted by the fluoride meter;

[0013] The wastewater first enters the rapid reaction zone. The first reagent automatic delivery point delivers the first reagent to the rapid reaction zone according to the instruction of the PLC control system. At the same time, the first agitator is started to promote the full mixing of the reagent and the wastewater. The rapid reaction zone conducts preliminary adsorption and precipitation of fluoride ions, laying the foundation for subsequent reactions.

[0014] The wastewater after rapid reaction flows from the top of the rapid reaction zone to the bottom of the medium-speed reaction zone, and the second reagent is automatically added to the medium-speed reaction zone at the second reagent automatic adding point. The second agitator is started to further promote the reaction, and the floccules gradually increase, thereby improving the removal efficiency of fluoride ions.

[0015] The wastewater after the medium-speed reaction flows from the top of the medium-speed reaction zone to the bottom of the slow-speed reaction zone. The third agent is automatically added to the slow-speed reaction zone from the third agent automatic addition point. The third agitator is started. In the slow-speed reaction zone, the reaction speed slows down, the floccules fully grow and precipitate, and the fluoride ions are removed more thoroughly.

[0016] The wastewater treated in the slow reaction zone flows into the flocculation and sedimentation zone, where the flocs are further precipitated;

[0017] The supernatant after precipitation flows into the clear water tank. At this time, the second pH meter installed in the clear water tank monitors the pH value of the clear water tank to ensure that the effluent water quality meets the requirements;

[0018] The sludge in the flocculation and sedimentation zone settles to the bottom, and part of it flows back to the bottom of the slow reaction zone through the first sludge return pipeline and the lifting pump, thereby increasing the particle size in the slow reaction zone and improving the flocculation effect.

[0019] At the same time, according to the actual situation, the PLC control system adjusts the amount of return sludge in the second sludge return pipeline through the control valve, and guides part of the sludge from the first sludge return pipeline between the lifting pump and the slow reaction zone to the bottom of the fast reaction zone, thereby improving the reaction efficiency of the fast reaction zone and the start-up speed of the defluorination effect;

[0020] During the operation of the system, the PLC control system continuously adjusts parameters such as the dosage of the reagent, the speed of the agitator, and the sludge return flow rate according to the real-time monitoring data of the fluoridation meter, the first pH meter, and the second pH meter to ensure the efficient and stable operation of the defluorination system.

[0021] Compared with the prior art, the present invention has achieved the following technical effects:

[0022] The present invention provides a defluorination system and a method of use. By setting fast, medium and slow reaction zones and corresponding automatic reagent delivery points, the defluorination process can be targeted at different stages to improve the defluorination effect. The connection between the PLC control system and the automatic reagent delivery point realizes the precise control of the reagent delivery, and automatically adjusts the reagent delivery amount according to different water inlet conditions and reaction requirements to ensure the efficient and stable operation of the defluorination system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 A schematic diagram of the structure of the defluorination system provided by the present invention;

[0025] In the figure: 1. water inlet pipe; 2. fast reaction zone; 3. automatic dosing point of the first agent; 4. medium-speed reaction zone; 5. automatic dosing point of the second agent; 6. slow reaction zone; 7. automatic dosing point of the third agent; 8. flocculation sedimentation zone; 9. clear water tank; 10. PLC control system; 11. first sludge return pipeline; 12. lifting pump; 13. second sludge return pipeline; 14. control valve; 15. fluoridation meter; 16. first pH meter; 17. second pH meter; 18. first agitator; 19. second agitator; 20. third agitator; 21.; 22.; 23.;. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The purpose of the present invention is to provide a defluorination system and a method of use to solve the problems existing in the above-mentioned prior art. The system has a simple structure, is easy to use, effectively reduces operating costs, and effectively improves the defluorination effect.

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] Embodiment 1

[0030] This embodiment provides a defluorination system, such as Figure 1 As shown, it includes: a water inlet pipe, a rapid reaction zone, a first agent automatic delivery point, a medium-speed reaction zone, a second agent automatic delivery point, a slow reaction zone, a third agent automatic delivery point, a flocculation sedimentation zone, a clear water tank and a PLC control system, wherein the rapid reaction zone is connected to the water inlet pipe; the first agent automatic delivery point is arranged above the rapid reaction zone to add the first agent to the rapid reaction zone; the bottom of the medium-speed reaction zone is connected to the top of the rapid reaction zone; the second agent automatic delivery point is arranged above the fast and medium-speed reaction zones to add the second agent to the medium-speed reaction zone; the bottom of the slow reaction zone It is connected to the top of the medium-speed reaction zone; the third agent automatic delivery point is set above the fast and slow reaction zones to add the third agent to the slow reaction zone; the top of the flocculation and sedimentation zone is connected to the top of the slow reaction zone, and the top of the clear water tank is connected to the top of the flocculation and sedimentation zone; the PLC control system is connected to the first agent automatic delivery point, the second agent automatic delivery point and the third agent automatic delivery point by signal. By setting fast, medium and slow reaction zones and corresponding agent automatic delivery points, the defluorination process can be targeted at different stages to improve the defluorination effect. The connection between the PLC control system and the agent automatic delivery point realizes the precise control of agent addition, automatically adjusts the agent dosage according to different water inlet conditions and reaction requirements, and ensures the efficient and stable operation of the defluorination system.

[0031] In a preferred solution of this embodiment, the defluorination system further includes a first sludge return pipeline and a lift pump, one end of the first sludge return pipeline is connected to the bottom of the flocculation sedimentation zone, and the other end is connected to the bottom of the slow reaction zone, and the lift pump is arranged on the first sludge return pipeline. The arrangement of the sludge return pipeline and the lift pump can return part of the sludge in the flocculation sedimentation zone to the slow reaction zone, increase the particle size in the slow reaction zone, and improve the flocculation effect. This helps to make full use of the active ingredients in the sludge and improve the overall treatment efficiency of the defluorination system.

[0032] In a preferred solution of this embodiment, the defluorination system further includes a second sludge return pipeline and a control valve, one end of the second sludge return pipeline is connected to the first sludge return pipeline between the lifting pump and the slow reaction zone, and the other end is connected to the bottom of the rapid reaction zone, and the control valve is arranged on the second sludge return pipeline, the control valve is connected to the PLC control system signal and can adjust the return sludge amount of the second sludge return pipeline, and the second sludge return pipeline is increased to lead part of the sludge from the first sludge return pipeline between the lifting pump and the slow reaction zone to the bottom of the rapid reaction zone, so that the activated sludge can be introduced at the early stage of the rapid reaction zone, and the reaction efficiency of the rapid reaction zone and the start-up speed of the defluorination effect can be improved. The control valve is connected to the PLC control system signal, and the precise adjustment of the return sludge amount can be realized. The sludge amount in the rapid reaction zone can be flexibly adjusted according to different operating conditions and water quality conditions, and the performance and stability of the entire defluorination system are further optimized. .

[0033] In a preferred solution of this embodiment, the defluorination system further includes a fluoridation meter, a first pH meter and a second pH meter, wherein the fluoridation meter is arranged in the water inlet pipe, the first pH meter is arranged in the rapid reaction zone, and the second pH meter is arranged in the clear water tank. The fluoridation meter, the first pH meter and the second pH meter are all connected to the PLC control system signal, and the fluoridation meter can monitor the fluoride content in the influent in real time, providing a basis for the PLC control system to adjust the dosage of the reagent. The first pH meter and the second pH meter monitor the pH values ​​of the rapid reaction zone and the clear water tank respectively, and the pH value is controlled within a suitable range through the precise regulation of the PLC control system to improve the defluorination effect.

[0034] In a preferred solution of this embodiment, the defluorination system further includes a first agitator, a second agitator and a third agitator, wherein the first agitator is arranged in the fast reaction zone, the second agitator is arranged in the medium-speed reaction zone, and the third agitator is arranged in the slow reaction zone. The agitators arranged in different reaction zones can promote the full mixing of the reagent and the wastewater, improve the reaction speed and uniformity, ensure that the defluorination reaction in each reaction zone can be carried out efficiently, and improve the overall performance of the defluorination system.

[0035] In a preferred solution of this embodiment, the first agent is a mixture of a fluorine removal agent and NaOH, the second agent is NaOH, and the third agent is PAM. The first agent is set as a mixture of a fluorine removal agent and NaOH, so that it can start to react efficiently with fluoride ions in the fast reaction zone. The addition of NaOH can adjust the pH value of the wastewater and create suitable acidity and alkalinity conditions for subsequent reactions. The second agent is NaOH, and the pH value is further adjusted in the medium-speed reaction zone to ensure that the reaction is carried out in a suitable environment and improve the removal efficiency of fluoride ions. The third agent is PAM (polyacrylamide). Adding PAM in the slow reaction zone can play a good flocculation role, making the formed flocs larger and more stable, accelerating the precipitation process, and improving the overall treatment effect and effluent quality of the defluorination system.

[0036] Embodiment 2

[0037] This embodiment provides a method for using the defluorination system as described in Embodiment 1, comprising the following steps:

[0038] Fluoride-containing wastewater enters the system through the water inlet pipe. At this time, the fluoride meter installed on the water inlet pipe monitors the fluoride content in the inlet water in real time and transmits the data to the PLC control system;

[0039] The PLC control system preliminarily determines the dosage of the first automatic agent delivery point, the second automatic agent delivery point and the third automatic agent delivery point according to the fluoride content data transmitted by the fluoride meter;

[0040] The wastewater first enters the rapid reaction zone. The first reagent automatic delivery point delivers the first reagent to the rapid reaction zone according to the instruction of the PLC control system. At the same time, the first agitator is started to promote the full mixing of the reagent and the wastewater. The rapid reaction zone conducts preliminary adsorption and precipitation of fluoride ions, laying the foundation for subsequent reactions.

[0041] The wastewater after rapid reaction flows from the top of the rapid reaction zone to the bottom of the medium-speed reaction zone, and the second reagent is automatically added to the medium-speed reaction zone at the second reagent automatic adding point. The second agitator is started to further promote the reaction, and the floccules gradually increase, thereby improving the removal efficiency of fluoride ions.

[0042] The wastewater after the medium-speed reaction flows from the top of the medium-speed reaction zone to the bottom of the slow-speed reaction zone. The third agent is automatically added to the slow-speed reaction zone from the third agent automatic addition point. The third agitator is started. In the slow-speed reaction zone, the reaction speed slows down, the floccules fully grow and precipitate, and the fluoride ions are removed more thoroughly.

[0043] The wastewater treated in the slow reaction zone flows into the flocculation and sedimentation zone, where the flocs are further precipitated;

[0044] The supernatant after precipitation flows into the clear water tank. At this time, the second pH meter installed in the clear water tank monitors the pH value of the clear water tank and controls the fluoride below 1 mg / l, reaching the Class III standard of surface water.

[0045] The sludge in the flocculation and sedimentation zone settles to the bottom, and part of it flows back to the bottom of the slow reaction zone through the first sludge return pipeline and the lifting pump, thereby increasing the particle size in the slow reaction zone and improving the flocculation effect.

[0046] At the same time, according to the actual situation, the PLC control system adjusts the amount of return sludge in the second sludge return pipeline through the control valve, and guides part of the sludge from the first sludge return pipeline between the lifting pump and the slow reaction zone to the bottom of the fast reaction zone, thereby improving the reaction efficiency of the fast reaction zone and the start-up speed of the defluorination effect;

[0047] During the operation of the system, the PLC control system continuously adjusts parameters such as the dosage of the reagent, the speed of the agitator, and the sludge return flow rate according to the real-time monitoring data of the fluoridation meter, the first pH meter, and the second pH meter to ensure the efficient and stable operation of the defluorination system.

[0048] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A defluorination system, characterized in that: include: Water inlet pipe, A rapid reaction zone, the rapid reaction zone being in communication with the water inlet pipe; A first agent automatic delivery point, the first agent automatic delivery point is arranged above the rapid reaction zone to add the first agent into the rapid reaction zone; A medium-speed reaction zone, wherein the bottom of the medium-speed reaction zone is connected to the top of the fast reaction zone; A second agent automatic delivery point, the second agent automatic delivery point is arranged above the fast and medium-speed reaction zone to add the second agent into the medium-speed reaction zone; A slow reaction zone, the bottom of which is connected to the top of the medium reaction zone; A third agent automatic delivery point, the third agent automatic delivery point is arranged above the fast and slow reaction zones to add the third agent into the slow reaction zone; a flocculation and sedimentation zone, the top of which is connected to the top of the slow reaction zone, A clear water tank, the top of which is connected to the top of the flocculation and sedimentation zone; A Plc control system is signal-connected to the first automatic medicine delivery point, the second automatic medicine delivery point and the third automatic medicine delivery point.

2. The defluorination system according to claim 1, characterized in that: It also includes a first sludge return pipeline and a lifting pump. One end of the first sludge return pipeline is connected to the bottom of the flocculation sedimentation zone, and the other end is connected to the bottom of the slow reaction zone. The lifting pump is arranged on the first sludge return pipeline.

3. The defluorination system according to claim 2, characterized in that: It also includes a second sludge return pipeline and a control valve, one end of the second sludge return pipeline is connected to the first sludge return pipeline between the lifting pump and the slow reaction zone, and the other end is connected to the bottom of the fast reaction zone. The control valve is arranged on the second sludge return pipeline, and the control valve is connected to the PLC control system signal and can adjust the amount of return sludge in the second sludge return pipeline.

4. The defluorination system according to claim 3, characterized in that: It also includes a fluoridation meter, a first pH meter and a second pH meter. The fluoridation meter is arranged in the water inlet pipe, the first pH meter is arranged in the rapid reaction zone, and the second pH meter is arranged in the clear water tank. The fluoridation meter, the first pH meter and the second pH meter are all connected to the PLC control system signal.

5. The defluorination system according to claim 4, characterized in that: It also includes a first agitator, a second agitator and a third agitator. The first agitator is arranged in the fast reaction zone, the second agitator is arranged in the medium-speed reaction zone, and the third agitator is arranged in the slow reaction zone.

6. A method for using the defluorination system according to any one of claims 1 to 5, characterized in that: The following steps are involved: Fluoride-containing wastewater enters the system through the water inlet pipe. At this time, the fluoride meter installed on the water inlet pipe monitors the fluoride content in the inlet water in real time and transmits the data to the PLC control system; The PLC control system preliminarily determines the dosage of the first automatic agent delivery point, the second automatic agent delivery point and the third automatic agent delivery point according to the fluoride content data transmitted by the fluoride meter; The wastewater first enters the rapid reaction zone. The first reagent automatic delivery point delivers the first reagent to the rapid reaction zone according to the instruction of the PLC control system. At the same time, the first agitator is started to promote the full mixing of the reagent and the wastewater. The rapid reaction zone conducts preliminary adsorption and precipitation of fluoride ions, laying the foundation for subsequent reactions. The wastewater after rapid reaction flows from the top of the rapid reaction zone to the bottom of the medium-speed reaction zone, and the second reagent is automatically added to the medium-speed reaction zone at the second reagent automatic adding point. The second agitator is started to further promote the reaction, and the floccules gradually increase, thereby improving the removal efficiency of fluoride ions. The wastewater after the medium-speed reaction flows from the top of the medium-speed reaction zone to the bottom of the slow-speed reaction zone. The third agent is automatically added to the slow-speed reaction zone from the third agent automatic addition point. The third agitator is started. In the slow-speed reaction zone, the reaction speed slows down, the floccules fully grow and precipitate, and the fluoride ions are removed more thoroughly. The wastewater treated in the slow reaction zone flows into the flocculation and sedimentation zone, where the flocs are further precipitated; The supernatant after precipitation flows into the clear water tank. At this time, the second pH meter installed in the clear water tank monitors the pH value of the clear water tank to ensure that the effluent water quality meets the requirements; The sludge in the flocculation and sedimentation zone settles to the bottom, and part of it flows back to the bottom of the slow reaction zone through the first sludge return pipeline and the lifting pump, thereby increasing the particle size in the slow reaction zone and improving the flocculation effect. At the same time, according to the actual situation, the PLC control system adjusts the amount of return sludge in the second sludge return pipeline through the control valve, and guides part of the sludge from the first sludge return pipeline between the lifting pump and the slow reaction zone to the bottom of the fast reaction zone, thereby improving the reaction efficiency of the fast reaction zone and the start-up speed of the defluorination effect; During the operation of the system, the PLC control system continuously adjusts the parameters of the dosage of the reagent, the speed of the agitator, and the sludge return flow according to the real-time monitoring data of the fluoridation meter, the first pH meter and the second pH meter to ensure the efficient and stable operation of the defluorination system.

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