Equipment for deeply treating fluorine-containing wastewater

Abstract

The utility model discloses equipment for deeply treating fluorine-containing wastewater. The equipment comprises a mixed reaction tank, a water pump, an automatic dosing machine, a pipeline mixer, an efficient fluorine remover, a water inlet and a water inlet pipe, the method is used for solving the problems that an existing deep defluorination technology is easy to block and scale, the problem of low solid-liquid separation efficiency and the problem of large occupied area of a sedimentation tank can be solved, and the method is free of secondary pollution, free of a regeneration process, long in service life, simple in equipment operation management, not easy to block and scale, high in automation degree and low in cost. After the fluorine-containing wastewater is treated by the equipment, the fluorine ion concentration is stably smaller than 1mg / L, the occupied area is small, the increasingly strict environment-friendly emission requirement can be met, and the equipment is particularly suitable for enterprises with fluorine-containing wastewater upgrading and reconstruction requirements and land shortage.

Description

Technical Field

[0001] The utility model relates to the technical field of fluorine-containing wastewater treatment, in particular to equipment for deep treatment of fluorine-containing wastewater. Background Art

[0002] With the development of fluorine-related industries in my country, such as fluorine chemicals, photovoltaics, and semiconductors, fluorine-containing wastewater, known for its high biotoxicity and ecological damage, has received increasing attention from both the government and society. Many regions in my country now require that fluorine-containing industrial wastewater have a fluoride ion concentration below 1 mg / L. Fluorine-containing industrial wastewater generally has a high concentration. Treatment methods such as two-stage calcium salt precipitation combined with coagulants can reduce the fluoride ion concentration to 15-20 mg / L, but further advanced treatment is required to reduce it below 1 mg / L. Additionally, some existing enterprises require upgrading and renovation, facing a shortage of land for environmental protection facilities.

[0003] Currently, the main methods for deep treatment of fluorine-containing wastewater on the market include ion exchange resin, adsorption, membrane separation, and defluorination agents. Considering the various current deep treatment processes for fluorine-containing wastewater, ion exchange equipment has high requirements for influent water quality. Ion exchange resins are prone to clogging and scaling and require regeneration, resulting in secondary pollution. The adsorbent regeneration process in the adsorption method is complex, has a short service life, and is subject to secondary pollution. The membrane components in the membrane separation method are easily affected by influent impurities, temperature, and pH, requiring high influent water quality and high costs for membrane separation equipment. The defluorination agent method has low solid-liquid separation efficiency, traditional sedimentation tanks occupy a large area, have high operating costs, and the effluent quality from deep treatment is unstable. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the utility model provides a deep treatment equipment for fluorine-containing wastewater, which is used to solve the problems of easy clogging and scaling in the existing deep fluoride removal technology. At the same time, it can solve the problems of low solid-liquid separation efficiency and large sedimentation tank footprint. It has no secondary pollution, does not require a regeneration process, has a long service life, is simple to operate and manage, and has a high degree of automation. After the fluorine-containing wastewater is treated by this equipment, the fluoride ion concentration is stably less than 1 mg / L.

[0005] The utility model discloses a deep treatment equipment for fluorine-containing wastewater, comprising a mixing reaction tank, a water pump, an automatic dosing machine, a pipeline mixer, a high-efficiency defluoridator, a water inlet, and a water inlet pipe;

[0006] The water inlet pipe is connected to the deceleration vertical pipe in the high-efficiency defluoridator, a reflector is arranged below the vertical pipe, an inclined plate is arranged at the vertical pipe, a flower plate is arranged at the upper part of the high-efficiency defluoridator, a water cap is arranged at the flower plate, and a water outlet is arranged on one side of the high-efficiency defluoridator above the flower plate; the area between the inclined plate sedimentation area of ​​the high-efficiency defluoridator and the flower plate is a suspended filter material bed.

[0007] The equipment for deep treatment of fluorine-containing wastewater uses suspended filter media, which is spherical, with a smooth and anti-scaling surface, and is self-cleaned regularly, making it less prone to scaling and clogging.

[0008] The filter material has a particle size of 2-3mm and a certain thickness. The filter material is electrostatically charged and can filter and adsorb extremely small suspended matter and crystal nuclei containing fluoride. The fluoride ion concentration of the treated water is stably less than 1mg / L.

[0009] The filter material is made of synthetic resin, which is resistant to acid corrosion and has a long service life. It does not need to be replaced for more than 15 years, does not require regeneration, and has no secondary pollution.

[0010] In deep-processing equipment for fluoride-containing wastewater, fluoride ions react with calcium ions (or aluminum ions) to form calcium fluoride (or aluminum fluoride). This reaction is reversible. At room temperature, calcium fluoride (or aluminum fluoride) dissolves in water and produces fluoride ions again. When calcium is added to fluoride-containing wastewater, the reaction results in three forms of fluoride ions in the water. The first is fluoride-containing crystal nuclei. Fluoride ions, which are originally dissolved, form fluoride-containing crystal nuclei upon encountering calcium ions. The second is that as these fluoride-containing crystal nuclei grow, they form fine, non-settling suspended matter. The third is that some of these fine, non-settling suspended matter collides with each other, and with the help of flocculants, some of them form fluoride-containing solids heavier than water, forming a precipitate. Of these three fluoride-containing substances, only the third, heavier-than-water fluoride solid, can be removed by the earth's gravity in the sedimentation tank. Fluorine-containing crystal nuclei and fine, non-settling suspended matter have a density close to that of water, making it impossible to separate them from the wastewater by gravity. This results in a high fluoride ion concentration in the treated wastewater. However, the device provided by the present invention can remove fluoride. This is because the device provided by the present invention includes a filter medium produced using proprietary technology that separates fluoride from the water by adsorbing the fluorine-containing crystal nuclei and fine, non-settling suspended matter. The thicker the filter medium, the higher the fluoride removal efficiency, and the fluoride ion concentration after treatment can be reduced to below 1 mg / l. Furthermore, the high-efficiency defluoridator of the present invention is equipped with inclined plates and other structures to separate fluorine-containing solids that are heavier than water from the water.

[0011] The chemical reaction equation involved in deep fluoride removal by traditional activated alumina adsorption method:

[0012]

[0013] Fluoride ions react with aluminum ions to form aluminum fluoride nuclei, fine suspended matter, and larger solids. Simultaneously, these nuclei, fine suspended matter, and larger solids dissolve in water, forming fluoride ions and aluminum ions. This reaction is reversible.

[0014] Due to the high solubility of calcium fluoride and aluminum fluoride at room temperature, relying solely on this reaction cannot achieve fluoride ion discharge standards. After the wastewater is neutralized with lime, the fluoride ion concentration can be reduced to about 15-20 mg / l. The present invention designs an adsorption filtration device that can remove crystal nuclei and fine suspended matter containing calcium fluoride and aluminum fluoride, and utilizes the common ion effect to ensure that the fluoride ion in the effluent is ≤1 mg / l. The main reaction equation during the treatment process of the high-efficiency defluoridation device is:

[0015] 2F - +Ca 2十 →CaF2↓

[0016] 3F - +Al 3+ →AlF3↓

[0017] After secondary calcium salt precipitation treatment, the fluoride-containing wastewater enters a mixing reaction tank, where a defluoridating agent (a 2-6% aluminum compound solution) is added for reaction. The effluent is pumped to a high-efficiency defluoridator. A pipeline mixer is installed between the pump and the high-efficiency defluoridator, where PAM is added. The high-efficiency defluoridator's inclined plate sedimentation and suspended filter beads' adsorption and filtration further reduce impurities such as suspended solids, fluoride ions, calcium ions, and fluoride crystal nuclei in the water. The effluent from the high-efficiency defluoridator flows by gravity to a clear water tank and meets discharge standards.

[0018] The high-efficiency defluoridator discharges sludge intermittently and automatically into the sludge concentration tank, where it is dehydrated using a plate and frame filter press. The filtrate is returned to the front end for reprocessing, and the filter cake is transported out for processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of the utility model's equipment for deep treatment of fluorine-containing wastewater. DETAILED DESCRIPTION

[0020] The following diagrams illustrate embodiments of the present invention.

[0021] The utility model discloses a deep treatment equipment for fluorine-containing wastewater, comprising a mixing reaction tank, a water pump, an automatic dosing machine, a pipeline mixer, a high-efficiency defluoridator, a water inlet, and a water inlet pipe;

[0022] The water inlet pipe is connected to the deceleration vertical pipe in the high-efficiency defluoridator, and a reflector is provided below the vertical pipe.

[0023] Plate, inclined plate is set at the vertical pipe, flower plate is set at the upper part of the high-efficiency defluoridator, water cap is set at the flower plate, and water outlet is set on one side of the high-efficiency defluoridator above the flower plate; the area between the inclined plate sedimentation area of ​​the high-efficiency defluoridator and the flower plate is the suspended filter material bed.

[0024] The equipment for deep treatment of fluorine-containing wastewater uses suspended filter media, which is spherical, with a smooth and anti-scaling surface, and is self-cleaned regularly, making it less prone to scaling and clogging.

[0025] The filter material has a particle size of 2-3mm and a certain thickness. The filter material is electrostatically charged and can filter and adsorb extremely small suspended matter and crystal nuclei containing fluoride. The fluoride ion concentration of the treated water is stably less than 1mg / L.

[0026] The filter material is made of synthetic resin, which is resistant to acid corrosion and has a long service life. It does not need to be replaced for more than 15 years, does not require regeneration, and has no secondary pollution.

[0027] In deep-processing equipment for fluoride-containing wastewater, fluoride ions react with calcium ions (or aluminum ions) to form calcium fluoride (or aluminum fluoride). This reaction is reversible. At room temperature, calcium fluoride (or aluminum fluoride) dissolves in water and produces fluoride ions again. When calcium is added to fluoride-containing wastewater, the reaction results in three forms of fluoride ions in the water. The first is fluoride-containing crystal nuclei. Fluoride ions, which are originally dissolved, form fluoride-containing crystal nuclei upon encountering calcium ions. The second is that as these fluoride-containing crystal nuclei grow, they form fine, non-settling suspended matter. The third is that some of these fine, non-settling suspended matter collides with each other, and with the help of flocculants, some of them form fluoride-containing solids heavier than water, forming a precipitate. Of these three fluoride-containing substances, only the third, heavier-than-water fluoride solid, can be removed by the earth's gravity in the sedimentation tank. Fluorine-containing crystal nuclei and fine, non-settling suspended matter have a density close to that of water, making it impossible to separate them from the wastewater by gravity. This results in a high fluoride ion concentration in the treated wastewater. However, the device provided by the present invention can remove fluoride. This is because the device provided by the present invention includes a filter medium produced using proprietary technology that separates fluoride from the water by adsorbing the fluorine-containing crystal nuclei and fine, non-settling suspended matter. The thicker the filter medium, the higher the fluoride removal efficiency, and the fluoride ion concentration after treatment can be reduced to below 1 mg / l. Furthermore, the high-efficiency defluoridator of the present invention is equipped with inclined plates and other structures to separate fluorine-containing solids that are heavier than water from the water.

[0028] The chemical reaction equation involved in deep fluoride removal by traditional activated alumina adsorption method:

[0029]

[0030] Fluoride ions react with aluminum ions to form aluminum fluoride nuclei, fine suspended matter, and larger solids. Simultaneously, these nuclei, fine suspended matter, and larger solids dissolve in water, forming fluoride ions and aluminum ions. This reaction is reversible.

[0031] Due to the high solubility of calcium fluoride and aluminum fluoride at room temperature, relying solely on this reaction cannot achieve fluoride ion discharge standards. After the wastewater is neutralized with lime, the fluoride ion concentration can be reduced to about 15-20 mg / l. The present invention designs an adsorption filtration device that can remove crystal nuclei and fine suspended matter containing calcium fluoride and aluminum fluoride, and utilizes the common ion effect to ensure that the fluoride ion in the effluent is ≤1 mg / l. The main reaction equation during the treatment process of the Bande filter defluoridation process is:

[0032] 2F - +Ca 2十 →CaF2↓

[0033] 3F - +Al 3+ →AlF3↓

[0034] After secondary calcium salt precipitation treatment, the fluoride-containing wastewater enters a mixing reaction tank, where a defluoridator (a 2-6% aluminum compound solution) is added for reaction. The effluent is pumped to a high-efficiency defluoridator. A pipeline mixer is installed between the pump and the high-efficiency defluoridator, where PAM is added. The high-efficiency defluoridator's inclined plate sedimentation and suspended filter beads' adsorption and filtration further reduce impurities such as suspended solids, fluoride ions, calcium ions, and fluoride crystal nuclei in the water. The effluent from the high-efficiency defluoridator flows by gravity to a clear water tank and meets discharge standards.

[0035] The high-efficiency defluoridator discharges sludge intermittently and automatically into the sludge concentration tank, where it is dehydrated using a plate and frame filter press. The filtrate is returned to the front end for reprocessing, and the filter cake is transported out for processing.

[0036] This treatment equipment is resistant to clogging and scaling, requires no regeneration process, produces no secondary pollution, has a long service life, and offers high solid-liquid separation efficiency. The fluoride ion concentration in treated wastewater is consistently less than 1 mg / L. It also requires a small footprint (for example, treating 50 cubic meters of wastewater per hour requires 30 square meters), meeting increasingly stringent environmental emission requirements. It is particularly suitable for land-constrained enterprises seeking to improve the quality of fluoride-containing wastewater.

Claims

1. A device for deep treatment of fluorine-containing wastewater, characterized in that: The invention comprises a mixing reaction tank, a water pump, an automatic dosing machine, a pipeline mixer, a high-efficiency defluoridator, a water inlet, and a water inlet pipe; wherein the water inlet pipe is connected to a deceleration vertical pipe in the high-efficiency defluoridator.

2. The device according to claim 1, characterized in that A reflecting plate is arranged below the vertical pipe, an inclined plate is arranged at the vertical pipe, a flower plate is arranged at the upper part of the high-efficiency defluoridator, a water cap is arranged at the flower plate, and a water outlet is arranged on one side of the high-efficiency defluoridator above the flower plate.

3. The device according to claim 2, characterized in that The equipment for deep treatment of fluorine-containing wastewater uses suspended filter media, which is spherical and has a smooth and anti-scaling surface. The filter material has a particle size of 2-3mm and a certain thickness. The filter material is electrostatically charged and can filter and adsorb extremely tiny suspended matter and crystal nuclei containing fluorine.

4. The device according to claim 1 or 2, characterized in that The area between the inclined plate sedimentation area and the flower plate of the high-efficiency defluoridator is a suspended filter material bed.

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