High-fluorine high-salt chemical organic wastewater treatment device

Abstract

The utility model discloses a high-fluorine high-salt chemical organic wastewater treatment device which comprises an adjusting tank, a fluorine removal reaction tank, a first plate-and-frame filter press, a hardness removal high-density tank, a multi-medium filter, a water production tank, a catalytic ozonation system and an MVR (mechanical vapor recompression) evaporation system which are sequentially arranged along the wastewater treatment direction, condensate water of the MVR evaporation system is recycled, a concentrated solution enters a triple-effect evaporation system, condensate water of the triple-effect evaporation system is recycled, and mother liquor and crystal salt are transported out for disposal. According to the utility model, organic pollutants, fluorine ions, calcium and magnesium ions, suspended matters and the like can be effectively removed, the reuse water quality standard is reached, the sewage reuse is realized, the production and environmental protection requirements are met, the treatment cost is reduced, and the operation stability of the treatment system is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater treatment, in particular to a treatment device for high-fluoride and high-salt chemical organic wastewater. Background Art

[0002] With the rapid development of industrialization, the problem of fluoride pollution has become increasingly prominent, posing a serious threat to the environment and human health. Fluorides mainly come from industrial wastewater, smelting processes, and natural water bodies. High-concentration fluorides not only pollute water bodies but also have long-term effects on soil and ecosystems. Therefore, the development and application of defluorination process technologies are particularly important.

[0003] In the existing fluorine-containing organic wastewater, the concentrations of fluoride ions and organic matters are relatively high, and the biodegradability of the wastewater is not high. It is necessary to first carry out advanced oxidation treatment and then enter the biochemical system for in-depth treatment. After two-stage treatment, the effluent water quality index of the wastewater can reach the discharge standard.

[0004] During biochemical treatment, the growth and metabolic processes of microorganisms are affected by various factors, and operating conditions such as temperature, pH value, and aeration volume need to be strictly controlled. In addition, nutrients need to be added regularly and the sludge concentration needs to be adjusted during the biochemical treatment process to ensure the normal growth and metabolism of microorganisms. Therefore, this process control is relatively complex. Content of the Utility Model

[0005] Aiming at the deficiencies in the existing technology, the utility model provides a treatment device for high-fluoride and high-salt chemical organic wastewater, which can be widely applied to the construction and upgrading of fluorochemical sewage treatment systems and has a very broad market application prospect.

[0006] The utility model discloses a treatment device for high-fluoride and high-salt chemical organic wastewater, including an adjustment tank, a defluorination reaction tank, a first plate and frame filter press, a hardness removal high-density tank, a multi-media filter, a water production tank, an ozone catalytic oxidation system, and an MVR evaporation system, which are arranged in sequence along the wastewater treatment direction. The condensed water of the MVR evaporation system is recycled, and the concentrated liquid enters the triple-effect evaporation system. The condensed water of the triple-effect evaporation system is recycled, and the mother liquor and crystal salts are transported out for disposal.

[0007] As a further improvement of the utility model, it further includes: a second plate and frame filter press;

[0008] The inlet of the second plate and frame filter press is connected to the sludge outlet of the hardness removal high-density tank, and the filtrate outlet of the second plate and frame filter press is connected to the adjustment tank.

[0009] As a further improvement of the present utility model, the defluorination reaction tank comprises a calcium chloride dosing tank, a coagulant aid stirring tank, a flocculant stirring tank and a sedimentation tank which are connected in sequence; a calcium chloride dosing system is connected to the calcium chloride dosing tank, a coagulant dosing system is connected to the coagulant aid stirring tank, a flocculant dosing system is connected to the flocculant stirring tank, and the calcium chloride dosing system, the coagulant dosing system and the flocculant dosing system are all composed of a chemical dissolving tank, a stirrer and a chemical dosing metering pump.

[0010] As a further improvement of the present utility model, the hard removal high-density tank comprises a dosing tank, a coagulant aid stirring tank, a flocculant stirring tank and a sedimentation tank which are connected in sequence. A sodium hydroxide dosing system and a sodium carbonate dosing system are respectively connected to the dosing tank, a coagulant dosing system is connected to the coagulant aid stirring tank, a flocculant dosing system is connected to the flocculant stirring tank, and the sodium hydroxide dosing system, the sodium carbonate dosing system, the coagulant dosing system and the flocculant dosing system are all composed of a chemical dissolving tank, a stirrer and a chemical dosing metering pump.

[0011] As a further improvement of the present utility model, the ozone catalytic oxidation system is an ozone catalytic oxidation tank.

[0012] As a further improvement of the present utility model, the MVR evaporation system comprises a preheater, an evaporator, a separator and a compressor.

[0013] As a further improvement of the present utility model, the triple-effect evaporation system comprises a triple-effect evaporator.

[0014] As a further improvement of the present utility model, the triple-effect evaporator adopts a forward flow reaction mode, and the influent water and steam both flow from the first effect to the second effect and then to the third effect.

[0015] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0016] The present utility model can effectively remove organic pollutants, fluoride ions, calcium and magnesium ions, suspended solids, etc. through the defluorination reaction tank, plate and frame filter press, hard removal high-density tank, multi-media filter, product water tank, ozone catalytic oxidation system, MVR evaporation system and triple-effect evaporation system, meet the reclaimed water quality standard, realize the reuse of sewage, meet the production and environmental protection requirements, reduce the treatment cost and improve the operation stability of the treatment system.

[0017] Each device and system adopted in the present utility model can, under suitable conditions, realize the single or combined process use of the defluorination reaction tank, plate and frame filter press, hard removal high-density tank, multi-media filter, product water tank, ozone catalytic oxidation system, MVR evaporation system and triple-effect evaporation system, and has the advantages of convenient operation, stable effluent and low operation cost. Description of the Drawings

[0018] Figure 1Schematic diagram of the high-fluoride and high-salt chemical organic wastewater treatment device disclosed by the present utility model.

[0019] In the figure:

[0020] 1. Regulation tank; 2. Defluorination reaction tank; 3. First plate and frame filter press; 4. Hardness removal high-density tank; 5. Multi-media filter; 6. Product water tank; 7. Ozone catalytic oxidation system; 8. MVR evaporation system; 9. Three-effect evaporation system; 10. Second plate and frame filter press. Specific embodiments

[0021] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some but not all of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0022] The following further describes the present utility model in detail with reference to the drawings:

[0023] As Figure 1 shown, the present utility model provides a high-fluoride and high-salt chemical organic wastewater treatment device, which includes a regulation tank 1, a defluorination reaction tank 2, a first plate and frame filter press 3, a hardness removal high-density tank 4, a multi-media filter 5, a product water tank 6, an ozone catalytic oxidation system 7 and an MVR evaporation system 8 arranged in sequence along the wastewater treatment direction. The condensed water of the MVR evaporation system 8 is recycled, and the concentrated liquid enters the three-effect evaporation system 9. The condensed water of the three-effect evaporation system 9 is recycled, and the mother liquor and crystal salts are transported out for disposal. The liquid inlet of the second plate and frame filter press 10 is connected to the sludge outlet of the hardness removal high-density tank 4, and the filtrate outlet of the second plate and frame filter press 10 is connected to the regulation tank 1. The dewatered sludge generated by the first plate and frame filter press 3 and the second plate and frame filter press 10 is harmlessly treated. Further, the connection between the above-mentioned various devices includes the device main body, valves, fittings, etc. arranged on the devices, pipelines connecting the two devices, and pump groups such as delivery pumps and sludge discharge pumps for power transmission.

[0024] Specifically:

[0025] The defluorination reaction tank 2 of the present utility model includes a calcium chloride dosing tank, a coagulant aid stirring tank, a flocculation stirring tank, and a sedimentation tank that are connected in sequence; a calcium chloride dosing system is connected to the calcium chloride dosing tank, a coagulant dosing system is connected to the coagulant aid stirring tank, a flocculant dosing system is connected to the flocculation stirring tank, and the calcium chloride dosing system, the coagulant dosing system, and the flocculant dosing system are all composed of a chemical dissolving tank, a stirrer, and a chemical dosing metering pump; during use, an excessive amount of calcium chloride is added to the wastewater in the calcium chloride dosing tank to control the reaction pH at 6 - 8, which is beneficial to the calcium fluoride precipitation reaction. Most of the fluoride ions in the sewage are removed through the calcium fluoride precipitation; a coagulant is added to the coagulant aid stirring tank for coagulation, and a flocculant is added to the flocculation stirring tank for flocculation.

[0026] The calcium fluoride precipitation slurry generated by the defluorination reaction tank 2 of the present utility model is pumped into the first plate and frame filter press 3 for sludge dewatering. The filtered sludge is transported out, and the filtrate enters the hardening removal high-density tank 4.

[0027] The hardening removal high-density tank 4 of the present utility model includes a chemical dosing tank, a coagulant aid stirring tank, a flocculation stirring tank, and a sedimentation tank that are connected in sequence. A sodium hydroxide dosing system and a sodium carbonate dosing system are respectively connected to the chemical dosing tank, a coagulant dosing system is connected to the coagulant aid stirring tank, a flocculation dosing system is connected to the flocculation stirring tank, and the sodium hydroxide dosing system, the sodium carbonate dosing system, the coagulant dosing system, and the flocculation dosing system are all composed of a chemical dissolving tank, a stirrer, and a chemical dosing metering pump; during use, sodium carbonate and sodium hydroxide are added to the wastewater in the chemical dosing tank to soften and remove excessive calcium ions and magnesium ions; a coagulant is added to the coagulant aid stirring tank for coagulation, a flocculant is added to the flocculation stirring tank for flocculation, and solid-liquid separation is carried out through the sedimentation tank to reduce the scaling and corrosion risks of subsequent equipment.

[0028] An acid-base dosing system is connected to the water production tank 6 of the present utility model. The acid-base dosing system is composed of a chemical dissolving tank, a stirrer, and a chemical dosing metering pump, and is used to adjust the pH of the wastewater in the water production tank.

[0029] The ozone catalytic oxidation system 7 of the present utility model is an existing conventional ozone catalytic oxidation tank. Specifically, the ozone catalytic oxidation tank includes an ozone catalytic oxidation zone and an effluent clear water zone, and the ozone catalytic oxidation zone is internally filled with an ozone catalyst; the ozone generation system includes an ozone generator, a nitrogen supplementation and instrument air assembly, a cooling circulation unit, a dosing unit, and a tail gas destruction unit. Through the strong oxidizing property of ozone and the catalytic action of the catalyst, refractory organic pollutants can be effectively treated, and the COD in the wastewater can be removed.

[0030] The MVR evaporation system 8 of the present utility model includes a preheater, an evaporator, a separator, a compressor (core component), etc. It has an existing conventional structure. Through evaporation concentration and evaporation crystallization of the wastewater under vacuum and low-temperature conditions, the solution containing non-volatile impurities can be concentrated and crystallized.

[0031] The triple-effect evaporation system 9 of the present utility model includes a triple-effect evaporator and a post-treatment system, which are of conventional structures; the triple-effect evaporation system is the core part and includes three evaporators, and each evaporator is called one effect; it is successively connected by a preheater, a heater, a separator, a condenser, a crystallizer, and a separator, and includes a lift pump, pipelines, valves, etc. connected to the preheater, heater, separator, condenser, and crystallizer; it includes an acid dosing system, a scale inhibitor dosing system, and an alkali solution dosing system, as well as the connection of dosing pumps and pipelines. The function of the post-treatment system is to dry and package the crystals generated by the evaporation system. Further, the triple-effect evaporator adopts a forward flow reaction mode, and the influent water and steam both flow from the first effect to the second effect and then to the third effect.

[0032] The present utility model provides a method for treating high-fluoride and high-salt chemical organic wastewater, including:

[0033] Step 1: The high-fluoride and high-salt chemical organic wastewater is lifted to the regulating tank 1 by a pump, and sewage observation is carried out in the regulating tank 1, and the water quality characteristics of the sewage are sampled and detected;

[0034] Step 2: The effluent of the regulating tank 1 is lifted to the defluorination reaction tank 2 by a pump, and calcium chloride is added to the defluorination reaction tank 2, and calcium ions react with fluoride ions to form a large amount of white calcium fluoride precipitate to remove fluoride ions in the wastewater;

[0035] Step 3: The effluent of the defluorination reaction tank 2 is lifted to the first plate and frame filter press 3 by a pump. Since a large amount of calcium fluoride precipitate generated by the high-fluoride wastewater and calcium chloride cannot be separated by ordinary filtration, the first plate and frame filter press 3 is used for sludge dewatering here, intercepting and separating sludge such as calcium fluoride in the water from the defluorination reaction tank 2. The filtrate of the first plate and frame filter press 3 enters the hardening high-density tank 4 for further treatment, and the filter cake is transported out and safely landfilled after stabilization / solidification;

[0036] Step 4: After the filtrate of the first plate and frame filter press 3 is lifted to the hardening high-density tank 4 by a pump, sodium hydroxide and sodium carbonate are added to the hardening high-density tank 4 to remove the hardness of calcium and magnesium ions and part of the fluoride ions in the water, reducing the scaling and corrosion risks of subsequent equipment;

[0037] Step 5: The effluent of the hardening high-density tank 4 is lifted to the multi-media filter 5 by a pump. Through the interception and adsorption of the multi-media filter 5, suspended solids and colloids in the water are removed, especially small particles that cannot be removed by precipitation technology can be effectively removed, and at the same time, there is also a certain degree of removal effect on COD;

[0038] Step 6: The effluent of the multi-media filter 5 is lifted to the product water tank 6 by a pump, and the pH is adjusted to about 8 to prepare for entering the subsequent system;

[0039] Step 7: The effluent from the production water tank 6 is pumped to the ozone catalytic oxidation system 7 to remove the organic matter in the wastewater, reduce the COD, and prepare for the subsequent entry into the evaporation system.

[0040] Step 8: The effluent from the ozone catalytic oxidation system 7 is pumped to the MVR evaporation system 8 to conduct primary concentration on the high-salt wastewater, further increase the TDS of the high-salt wastewater. Low-boiling organic matters, etc. in the MVR evaporation system 8 escape with the water vapor and form condensate water that enters the reused water tank.

[0041] Step 9: The concentrated liquid from the MVR evaporation system 8 is pumped to the triple-effect evaporation system 9. After further concentration, mother liquor, miscellaneous salts, and distilled water are obtained. The effluent of the triple-effect evaporation system meets the quality requirements of reused water and can be reused within the plant; the mother liquor of the triple-effect evaporation system is landfilled or incinerated after solidification, and the miscellaneous salts are treated harmlessly.

[0042] Step 10: The second plate and frame filter press 10 conducts pressure filtration on the sludge generated by the hardening removal high-density tank 4. The pressure filtrate generated enters the regulation tank 1 for re-treatment, and the treated sludge is disposed of by landfill.

[0043] Example:

[0044] The present utility model provides a method for treating high-fluoride and high-salt chemical industrial organic wastewater, including:

[0045] S1: The high-fluoride and high-salt chemical industrial organic wastewater is pumped to the regulation tank 1 through a pump for sewage observation, and samples are taken to detect the water quality characteristics of the sewage. The water quality indicators are as follows: fluoride ion 8500 mg / L, COD 5000 mg / L, TDS = 160000 mg / L.

[0046] S2: The effluent from the regulation tank 1 is pumped to the defluorination reaction tank 2, and excessive calcium chloride is added to the defluorination reaction tank 2 through the calcium chloride dosing system. Calcium ions react with fluoride ions to form a large amount of white calcium fluoride precipitate to remove the fluoride ions in the wastewater. The fluoride ions in the wastewater are reduced from 8500 mg / L to within 20 mg / L, and the COD is reduced to about 3400 mg / L.

[0047] S3: The effluent from the defluorination reaction tank 2 is pumped to the first plate and frame filter press 3. Since a large amount of calcium fluoride precipitate generated by the high-fluoride wastewater and calcium chloride cannot be separated by ordinary filtration, the first plate and frame filter press 3 is used here for sludge dewatering. The pressure filtrate of the first plate and frame filter press 3 enters the hardening removal high-density tank 4 for further treatment, and the filter cake is transported out and safely landfilled after stabilization / solidification;

[0048] S4. After the filtrate pressed by the first plate and frame filter press 3 enters the hardening high-density pond 4, sodium hydroxide and sodium carbonate are added to the hardening high-density pond 4 through the sodium hydroxide dosing system and the sodium carbonate dosing system. Sodium hydroxide can adjust the pH of the wastewater to keep it around 11.5, and it can also cause most of the calcium and magnesium ions in the wastewater to - precipitate with OH - . At the same time, the added sodium carbonate is supplemented to cooperate with the removal of calcium ions in the wastewater. The calcium ions in the effluent from the previous stage are reduced from 4000 mg / L to less than 100 mg / L, and at the same time, the COD is reduced from about 3400 mg / L to about 3000 mg / L.

[0049] S5. The effluent from the hardening high-density pond 4 is lifted by a pump to the multi-media filter 5. Through the interception and adsorption of the multi-media filter 5, the suspended solids and colloids in the water are removed, especially the tiny particles that cannot be removed by the precipitation technology can be effectively removed. At the same time, there is also a certain degree of removal effect on the COD.

[0050] S6. The effluent from the multi-media filter 5 is lifted by a pump to the production water tank 6, and the pH of the wastewater is adjusted to about 8 through a pH regulator (acid or alkali) to prepare for entering the subsequent system.

[0051] S7. The effluent from the production water tank 6 is lifted by a pump to the ozone catalytic oxidation system 7. In the ozone catalytic oxidation system 7, the strong oxidizing property of ozone and the adsorption and catalytic characteristics of the catalyst are combined, and most of the organic matter in the wastewater can be effectively removed, and the COD of the wastewater is reduced from about 3000 mg / L to less than 2000 mg / L.

[0052] S8. The ozone catalytic oxidation system 7 is lifted by a pump to the MVR evaporation system 8. In the MVR evaporation system 8, the high-salt sewage is preliminarily concentrated, and the TDS of the high-salt sewage is further increased. The low-boiling organic matters in the MVR evaporation system 8 escape with the water vapor and form condensate water to enter the reused water tank.

[0053] S9. The concentrated liquid of the MVR evaporation system 8 is lifted by a pump to the triple-effect evaporation system 9. The pH value of the wastewater is adjusted to about 5 by adding acid and alkali at the water inlet end of the triple-effect evaporation system 9. After pretreatment, the wastewater enters the distilled water plate heat exchanger to exchange heat with the distilled water generated by the system, so that the temperature of the original solution is increased, and the distilled water is discharged from the system after the temperature is reduced. Then the original solution enters the preheater to be further preheated with the secondary steam generated by the triple-effect evaporation system of the system, thus condensing part of the secondary steam. The preheated original solution then enters the triple-effect evaporation system. The triple-effect evaporation system evaporates and concentrates or evaporates and crystallizes the wastewater under vacuum and low-temperature conditions, removing the inorganic salts in the wastewater by evaporation. The crystal slurry is dehydrated and separated by a centrifuge, and the generated mother liquor is landfilled after solidification, and the miscellaneous salts are harmlessly treated. The TDS of the distilled water generated by evaporation can be reduced to less than 1000 mg / L; the COD can be reduced to less than 100 mg / L; the TN can be reduced to less than 15 mg / L, and the produced water meets the standards and can be recycled.

[0054] S10. The second plate and frame filter press 10 filters the sludge generated by the hardening removal high-density tank 4. The generated filter press filtrate enters the regulation tank 1 for re-treatment. The water content of the treated sludge is reduced to less than 80%, and it is disposed of by landfill.

[0055] The advantages of the present utility model are as follows:

[0056] Through the defluorination reaction tank, plate and frame filter press, hardening removal high-density tank, multi-media filter, water production tank, ozone catalytic oxidation system, MVR evaporation system, and triple-effect evaporation system, the present utility model can effectively remove organic pollutants, fluoride ions, calcium and magnesium ions, suspended solids, etc., meet the reclaimed water quality standards, realize the reuse of sewage, meet the production and environmental protection requirements, reduce the treatment cost, and improve the operation stability of the treatment system.

[0057] Under suitable conditions, each device and system adopted in the present utility model can be used alone or in combination in the processes of the defluorination reaction tank, plate and frame filter press, hardening removal high-density tank, multi-media filter, water production tank, ozone catalytic oxidation system, MVR evaporation system, and triple-effect evaporation system, and has the advantages of convenient operation, stable effluent, and low operation cost.

[0058] The above is only the preferred embodiment of the present utility model and is not used to limit the present utility model. For those skilled in the art, the present utility model can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A high-fluorine and high-salt chemical organic wastewater treatment device, characterized in that: It includes a regulating tank, a fluorine removal reaction tank, a first plate and frame filter press, a hardness removal high-density tank, a multi-media filter, a water production tank, an ozone catalytic oxidation system and an MVR evaporation system which are arranged in sequence along the wastewater treatment direction. The condensed water of the MVR evaporation system is reused and the concentrated liquid enters the triple-effect evaporation system. The condensed water of the triple-effect evaporation system is reused and the mother liquor and crystallized salt are transported out for disposal.

2. The high-fluorine and high-salt chemical organic wastewater treatment device according to claim 1, characterized in that: Also includes: Second plate and frame filter press; The liquid inlet of the second plate-frame filter press is connected to the mud outlet of the hardness removal high-density tank, and the filtrate outlet of the second plate-frame filter press is connected to the regulating tank.

3. The high-fluorine and high-salt chemical organic wastewater treatment device according to claim 1 or 2, characterized in that: The defluorination reaction tank comprises a calcium chloride dosing tank, a coagulant stirring tank, a flocculation stirring tank and a sedimentation tank which are connected in sequence; the calcium chloride dosing tank is connected with a calcium chloride dosing system, the coagulant stirring tank is connected with a coagulant dosing system, the flocculation stirring tank is connected with a flocculant dosing system, and the calcium chloride dosing system, the coagulant dosing system and the flocculant dosing system are all composed of a dissolving tank, an agitator and a dosing metering pump.

4. The high-fluorine and high-salt chemical organic wastewater treatment device according to claim 1 or 2, characterized in that: The hardness removal high-density tank includes a dosing tank, a coagulant stirring tank, a flocculation stirring tank and a sedimentation tank which are connected in sequence. The dosing tank is respectively connected with a sodium hydroxide dosing system and a sodium carbonate dosing system, the coagulant stirring tank is connected with a coagulant dosing system, and the flocculation stirring tank is connected with a flocculant dosing system. The sodium hydroxide dosing system, the sodium carbonate dosing system, the coagulant dosing system and the flocculant dosing system are all composed of a dissolving tank, an agitator and a dosing metering pump.

5. The high-fluorine and high-salt chemical organic wastewater treatment device according to claim 1 or 2, characterized in that: The ozone catalytic oxidation system is an ozone catalytic oxidation tank.

6. The high-fluorine and high-salt chemical organic wastewater treatment device according to claim 1 or 2, characterized in that: The MVR evaporation system includes a preheater, an evaporator, a separator and a compressor.

7. The high-fluorine and high-salt chemical organic wastewater treatment device according to claim 1 or 2, characterized in that: The triple-effect evaporation system comprises a triple-effect evaporator.

8. The high-fluorine and high-salt chemical organic wastewater treatment device according to claim 7, characterized in that: The triple-effect evaporator adopts a co-current reaction mode, and the inlet water and steam are both from the first effect to the second effect and then to the third effect.

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