CN112811669A - Fluorine-containing industrial wastewater treatment system and treatment method thereof - Google Patents
Fluorine-containing industrial wastewater treatment system and treatment method thereof Download PDFInfo
- Publication number
- CN112811669A CN112811669A CN202110121110.3A CN202110121110A CN112811669A CN 112811669 A CN112811669 A CN 112811669A CN 202110121110 A CN202110121110 A CN 202110121110A CN 112811669 A CN112811669 A CN 112811669A
- Authority
- CN
- China
- Prior art keywords
- tank
- fluorine
- sludge
- reaction tank
- sedimentation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F9/00—Multistage treatment of water, waste water or sewage
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/42—Treatment of water, waste water, or sewage by ion-exchange
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
- C02F1/5236—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2101/00—Nature of the contaminant
- C02F2101/10—Inorganic compounds
- C02F2101/12—Halogens or halogen-containing compounds
- C02F2101/14—Fluorine or fluorine-containing compounds
Abstract
The invention provides a fluorine-containing industrial wastewater treatment system and a treatment method thereof, wherein the method comprises the following steps: adjusting pH, primary defluorination, secondary defluorination, precipitation clarification, resin defluorination and sludge treatment. The defluorination treatment method can lead the treated high-concentration fluorine-containing wastewater to have stable water outlet and reach the discharge standard of less than 10mg/L, and the treated wastewater can be recycled and also can be directly discharged.
Description
Technical Field
The invention relates to the technical field of industrial wastewater defluorination, in particular to a fluorine-containing industrial wastewater treatment system and a treatment method thereof.
Background
The main treatment method of the fluorine-containing wastewater at present is a chemical precipitation method, and the method has the problems that the treated effluent is difficult to reach the standard (less than 10mg/L), the treated effluent has unstable water quality, excessive medicament consumption, large sludge generation amount, high water content and the like. Freezing method, ion exchange resin method, ultrafiltration method, electrodialysis, etc. because the treatment cost is high, the efficiency of defluorination is low, and the method stays in the experimental stage, and is rarely popularized and applied to the treatment of industrial fluorine-containing wastewater. The common defluorination process is the addition of calcium ions to produce calcium fluoride precipitate due to the production of CaF2The precipitate is wrapped in Ca (OH)2The surface of the particles can not be fully utilized, so that the lime consumption is large. When lime milk is added, even if the pH value of the wastewater reaches 12, the concentration of the fluorine ions in the wastewater can be reduced to about 15mg/L, and the content of suspended matters in the wastewater is very high.
Disclosure of Invention
In view of this, the present invention is directed to a fluorine-containing industrial wastewater treatment system and a treatment method thereof, so that the quality of the effluent water treated by the fluorine-containing wastewater treatment method is stable and can reach the discharge standard of less than 10 mg/L.
In order to achieve the purpose, the technical scheme of the invention is realized as follows:
a fluorine-containing industrial wastewater treatment system comprises a primary coagulation sedimentation reaction tank, a secondary coagulation sedimentation reaction tank, a mechanical stirring clarification tank, a fluorine-removing resin tank and a clean water tank which are sequentially connected; the primary coagulation sedimentation reaction tank, the secondary coagulation sedimentation reaction tank and the mechanical stirring clarification tank are arranged in a fall sequence, so that the wastewater is automatically and sequentially treated in the primary coagulation sedimentation reaction tank, the secondary coagulation sedimentation reaction tank and the mechanical stirring clarification tank; the primary coagulation sedimentation reaction tank, the secondary coagulation sedimentation reaction tank and the mechanical stirring clarification tank are also connected with a sludge sedimentation tank through a sludge pump, and the middle lower part of the secondary coagulation sedimentation reaction tank is also connected with the primary coagulation sedimentation reaction tank through a water pump; the mechanical stirring clarification tank is connected with the defluorination resin tank through a water pump, and the defluorination resin tank is connected with the clean water tank through a water pump.
Further, be equipped with the folded plate of 2 vertical settings in the one-level coagulating sedimentation reaction tank, the folded plate is with the inside triplex box structure that falls into aeration tank, agitator tank and the static caisson that communicates in proper order from a left side to the right side of one-level coagulating sedimentation reaction tank, and forms S type flow path between aeration tank to the static caisson, is equipped with the aeration pipe in the aeration tank, is equipped with the stirring rake in the agitator tank.
The structure is adopted for the purposes of increasing hydraulic disturbance, enhancing turbulent flow, achieving the purpose of coagulation and preventing formed fluorine ions from being wrapped and not reacting with a medicament completely; the water is fed into the aeration tank and an aeration stirring method is adopted, the aeration stirring is carried out to ensure that the bottom reaction is thorough, the aeration head is arranged at the bottom of the reaction tank, the sediment at the bottom and the unreacted medicament can be stirred to be fully reflected, the sediment cannot be utilized due to high specific gravity, and the stirring is promoted; the stirring box adopts the stirring paddle for stirring, the stirring speed can be controlled by the stirring paddle, most of the reaction has occurred at the moment, the stirring with large strength is not needed, and the sediment is needed to be slowly generated, so that the stirring speed can be reduced, and the slow mixing can be carried out. The two stirring modes are quick and slow, aeration is more thorough from the bottom to the top, and the stirring paddle is used for accelerating the generation of the florescence flocs through slow coagulation and preparing for better flocculation precipitation in the next step. And finally, a static settling tank is arranged, the disturbance of water flow is slowed down, the sedimentation of sludge is facilitated, and the sludge is discharged discontinuously at the bottom.
Furthermore, a first side sewage draining outlet and a second side sewage draining outlet are respectively arranged on two sides of a bottom sewage draining outlet of the mechanical stirring clarification tank.
The clarification tank is a mechanical stirring clarification tank, aiming at finishing flocculation, sedimentation and clarification in the clarification tank and ensuring stable water outlet, the clarification tank is originally provided with sludge discharge ports at a sludge concentration chamber and the bottom part respectively, and the sludge discharge port of the sludge concentration chamber aims at preventing sludge accumulation at a groove part to influence the turbidity of water; the mud drain outlet of bottom discharges mud scraper and hangs the mud of bottom, nevertheless because here sludge stacking density is big, phenomenon such as jam appears very easily, so first side drain and second side drain have been set up in its both sides, the purpose is that mud piles up on bottom tipping bucket both sides when stopping or breaking down in order to prevent to shut down, influence mud scraper normal operating, these two mud drains also can be regarded as washing the mouth simultaneously, wash the unable mud of getting rid of in bottom, be favorable to reducing the desilting frequency of depositing reservoir.
Further, the inside of the defluorination resin tank is sequentially provided with an activated carbon adsorbent particle layer, an iron sand filter material, a rare earth filter material and a special defluorination resin layer from bottom to top, and the thicknesses of the activated carbon adsorbent particle layer, the iron sand filter material, the rare earth filter material and the special defluorination resin layer are sequentially 80-100 mm, 180-200 mm and 650-700 mm.
Further, the particle size of the iron-carbon particles is 3-5 mm, the particle size of the iron sand filter material is 2.0-3.0 mm, the particle size of the rare earth filter material is 1.0-0.5 mm, and the particle size of the special defluorination resin layer is 0.4-0.6 mm.
The resin is fed with water from the upper part, and the fluorine ion concentration of the discharged water is ensured to be smaller and less than 5ppm by the special fluorine-removing resin aiming at the fluorine ion; the second layer of rare earth and the third layer of iron sand are used for filtering impurity particles in the wastewater; the lowest active carbon layer aims at adsorbing organic matters which do not react in the wastewater, and ensuring that the effluent fluorine reaches the standard and other ions such as the organic matters reach the standard.
The invention also provides a fluorine-containing industrial wastewater treatment method, which comprises the following steps:
1) adjusting the pH value: adding alkaline regulators such as calcium chloride, lime, soda ash and the like into the primary coagulation sedimentation reaction tank, and adjusting the pH value to be 11 or more;
2) primary defluorination: continuously feeding the mixture into a first-stage coagulation sedimentation reaction tank according to the molar ratio Ca2+:F-Adding soluble calcium salt such as calcium chloride and calcium phosphate into the powder 1, stirring for 30-40min, and adding the soluble calcium salt to reduce the solubility of calcium fluoride due to the homoionic effect, thereby being beneficial to accelerating the production of calcium fluoride precipitate; in addition, discharging the sediment into a sludge sedimentation tank (6) every 30-60 min, wherein the sediment is discharged for 3-5min each time;
3) secondary fluorine removal: introducing the supernatant of the wastewater obtained in the step 2) into a secondary coagulation sedimentation reaction tank, adding soluble calcium salt, stirring for 5-10min, adding a flocculating agent such as PAC (polyaluminium chloride), PFS (PFS), phosphoric acid, phosphate and the like, matching calcium chloride, and forming a complex with fluoride ions to achieve the effect of removing the fluoride ions until the final concentration of the fluoride ions is 10mg/L for flocculation sedimentation; in addition, discharging the sediment into a sludge sedimentation tank every 30-60 min, wherein the sediment is discharged for 3-5min each time; the obtained supernatant of the wastewater also flows back to the primary coagulation sedimentation reaction tank;
4) and (3) settling: introducing the supernatant of the wastewater obtained in the step 3) into a mechanical stirring clarification tank (3) for sedimentation clarification, operating the mechanical stirring clarification tank (3) for 1h, stopping the machine for 10-20 min, intermittently operating the sedimentation tank to ensure that the effluent is clarified and stable, simultaneously adding a flocculating agent for sedimentation, and discharging the bottom sludge into a sludge sedimentation tank; the clarification tank runs intermittently, if sludge stays for a long time, the added medicine can wrap sludge flocs, the efficiency of reaction with fluorine is low, and meanwhile, the phenomenon that the effluent of the clarification tank turns over is turbid is also avoided;
5) and (3) resin defluorination: introducing the supernatant of the wastewater obtained in the step 4) into a defluorination resin tank, keeping the retention time of the supernatant of the wastewater in resin for 30-40min, and introducing the treated wastewater into a clean water tank;
6) sludge treatment: PAC and PAM are added into the sludge sedimentation tank, which is beneficial to the flocculation sedimentation of the sludge and achieves the purposes of stable water outlet and quick flocculation; and then, carrying out plate-and-frame filter pressing on the sludge and transporting the sludge outwards, and refluxing the supernatant of the sludge sedimentation tank to a primary coagulation sedimentation reaction tank.
The intermittent sludge discharge to the sludge sedimentation tank from the primary coagulation sedimentation reaction tank and the secondary coagulation sedimentation reaction tank is used for preventing the sludge from blocking a discharge port, meanwhile, the sludge discharge is used for reducing the concentration in the tank, the periodic sludge discharge is used for maintaining the stable water outlet of the clarification tank, in addition, the floc sedimentation time is ensured, the sludge can not be discharged without sedimentation, and a flushing port can be arranged at the bottom of the tank; the intermittent sludge discharge is to make the formed complex stay in the pool better to play a role of adsorption;
the method aims to reduce the content of fluorine ions at the bottom of the secondary coagulation sedimentation reaction tank, prevent the release of fluorine ions contained in sludge accumulated at the bottom and increase the content of fluorine ions in secondary effluent, and has the advantages of relatively diluting the concentration of fluorine ions in the primary coagulation sedimentation reaction tank and fully utilizing medicaments. The reflux contains the medicament which does not completely react, the reflux is carried out in the first-stage coagulation sedimentation reaction tank, the reagent can be recycled, the effect of reducing the dosage of the reagent can be achieved by long-term circulation, the reflux is also used for increasing free fluoride ions in the reflux, incomplete reaction caused by wrapping is avoided, the concentration of the fluoride ions is increased, the reaction is promoted to be carried out in the forward direction, and calcium fluoride precipitate is produced.
Furthermore, the primary coagulation sedimentation reaction tank adopts a folded plate triple box structure, the triple box comprises an aeration box, a stirring box and a static sedimentation box which are sequentially communicated, and wastewater firstly passes through the aeration box and is aerated and simultaneously stirred; then the mixture enters a stirring box and is stirred under the action of a stirring paddle; finally, the sludge enters a static settling tank to precipitate the generated calcium fluoride and the sludge is intermittently discharged into a sludge settling tank.
Further, the reflux amount in the step 3) is 15-20% of the water inflow amount of the secondary coagulation sedimentation reaction tank.
This backward flow volume had both guaranteed to get into one-level coagulating sedimentation reaction tank and can utilize the medicament, can not destroy the reaction in second grade coagulating sedimentation reaction tank simultaneously, if too much backward flow, the water yield of staying in second grade coagulating sedimentation reaction tank diminishes, increases the energy consumption simultaneously.
Further, in the step 1), before adding calcium chloride, adding inorganic acid to adjust the pH of the wastewater to 6-8.
Fluoride is not the only contaminant to be removed from the wastewater, and therefore an appropriate treatment method is selected according to the actual situation. If sodium carbonate and sodium bicarbonate are dissolved in the fluorine-containing wastewater, lime or calcium chloride is directly added, and the fluorine removal effect is reduced. This is because a certain amount of strong electrolyte exists in the wastewater, which produces a salt effect, increases the solubility of calcium fluoride, and reduces the defluorination effect. At the moment, the pH value of the wastewater is adjusted to 6-8 by using inorganic acid, and then the reaction is carried out according to the above steps so as to effectively remove fluorine ions.
Further, the method comprises adding acid to the wastewater to generate hydrofluoric acid and evaporating the hydrofluoric acid before adjusting the pH.
When the fluorine ion concentration in the wastewater is more than 50ppm and less than 1000ppm, the method can be adopted, if the fluorine ion content of the fluorine-containing wastewater is more than 1000ppm, coagulating sedimentation removal is not recommended, acid can be added to form hydrofluoric acid, evaporation is carried out, and high-concentration hydrofluoric acid is recovered after water vapor in the wastewater is evaporated.
Compared with the prior art, the fluorine-containing industrial wastewater treatment system and the treatment method thereof have the following advantages:
1. the fluorine-containing industrial wastewater treatment system and the treatment method thereof provided by the invention are finally provided with the fluorine-removing resin which can remove suspended matters, and the fluorine-removing resin is used as a final layer of guarantee, so that the concentration of fluorine ions in effluent water every time is less than 10ppm no matter how large the inflow fluctuates, the quality of effluent water treated by the fluorine-containing wastewater is stable and reaches the standard, the concentration of fluorine in secondary effluent water is less than 10ppm, the concentration of fluorine ions in effluent water treated by the fluorine-removing resin is less than 5ppm, the discharge requirements of various places are met, and the treated wastewater can be recycled and also can be directly discharged.
2. The method for treating the fluorine-containing industrial wastewater, disclosed by the invention, adopts calcium chloride and also adds agents such as phosphoric acid, calcium hydroxide, polyaluminium chloride and the like, so that the fluorine ion precipitation is accelerated, and meanwhile, the sludge settling property is also ensured.
3. The fluorine-containing industrial wastewater treatment system and the treatment method thereof finally adopt the defluorination resin, and aim to reduce the concentration of fluorine ions in the effluent to be lower or even less than 5ppm, the resin adopts a multilayer stacking structure, and defluorination can also ensure other effluent indexes to reach the standard, such as turbidity, COD, chromaticity and the like.
4. The one-level coagulating sedimentation reaction tank adopts a triple box structure, has two stirring modes of aeration and stirring simultaneously, enhances the disturbance of water and fully mixes the medicament, and improves the defluorination effect.
5. The purpose is in order to reduce second grade coagulating sedimentation reaction tank bottom fluorinion content, prevent to pile up the release of the fluorinion that contains in the mud of bottom, increase second grade coagulating sedimentation reaction tank effluent fluorinion content, the benefit of flowing back to first grade coagulating sedimentation reaction tank is the fluorinion concentration that can dilute the one-level coagulating sedimentation reaction tank relatively, also be the make full use of to the medicament simultaneously.
6. The clarification tank is a mechanical stirring clarification tank, aiming at finishing flocculation, sedimentation and clarification in the clarification tank and ensuring stable water outlet, the clarification tank is originally provided with sludge discharge ports at a sludge concentration chamber and the bottom part respectively, and the sludge discharge port of the sludge concentration chamber aims at preventing sludge accumulation at a groove part to influence the turbidity of water; the mud drain outlet of bottom discharges mud scraper and hangs the mud of bottom, nevertheless because here sludge stacking density is big, phenomenon such as jam appears very easily, so first side drain and second side drain have been set up in its both sides, the purpose is that mud piles up on bottom tipping bucket both sides when stopping or trouble in order to prevent, influence mud scraper normal operating, these two places mud drains also can regard as the mouth of washing simultaneously, wash the unable mud of getting rid of in bottom, be favorable to reducing the desilting frequency of clarification tank, the play water of mechanical stirring clarification tank is clean than general sedimentation tank play water, and stable.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:
FIG. 1 is a schematic structural diagram of a fluorine-containing industrial wastewater treatment system according to an embodiment of the present invention;
FIG. 2 is a top view of the internal structure of a primary coagulation-precipitation reaction tank according to an embodiment of the present invention;
fig. 3 is a schematic structural view of a mechanical stirring clarifier according to an embodiment of the invention.
Description of reference numerals:
1-first-stage coagulating sedimentation reaction tank; 11-an aeration tank; 12-a stirring box; 13-a static caisson; 14-folding plates; 2-a second-stage coagulating sedimentation reaction tank; 3-mechanically stirring the clarification tank; 31-a first side sludge discharge port; 32-a second side mud outlet; 4-defluorination resin tank; 5-a clean water tank; 6-sludge settling tank.
Detailed Description
It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.
In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.
The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.
Example 1
As shown in fig. 1, a fluorine-containing industrial wastewater treatment system comprises a primary coagulation sedimentation reaction tank 1, a secondary coagulation sedimentation reaction tank 2, a mechanical stirring clarification tank 3, a fluorine removal resin tank 4 and a clean water tank 5 which are connected in sequence; the primary coagulation sedimentation reaction tank 1, the secondary coagulation sedimentation reaction tank 2 and the mechanical stirring clarification tank 3 are arranged in a sequential fall manner, so that the wastewater is automatically and sequentially treated in the primary coagulation sedimentation reaction tank 1, the secondary coagulation sedimentation reaction tank 2 and the mechanical stirring clarification tank 3; the primary coagulation sedimentation reaction tank 1, the secondary coagulation sedimentation reaction tank 2 and the mechanical stirring clarification tank 3 are also connected with a sludge sedimentation tank 6 through a sludge pump, two thirds of the secondary coagulation sedimentation reaction tank 2 are also connected with the primary coagulation sedimentation reaction tank 1 through a water pump, namely supernatant on the upper part of the sediment liquid at the bottom flows back; the mechanical stirring clarification tank 3 is connected with a defluorination resin tank 4 through a water pump, and the defluorination resin tank 4 is connected with a clean water tank 5 through the water pump.
Specifically, as shown in fig. 2, 2 vertically arranged folded plates 14 are arranged in the primary coagulation-sedimentation reaction tank 1, the folded plates 14 divide the interior of the primary coagulation-sedimentation reaction tank 1 into a triple box structure of an aeration tank 11, a stirring tank 12 and a static caisson 13 which are sequentially communicated from left to right, an S-shaped flow path is formed between the aeration tank 11 and the static caisson 13, an aeration pipe is arranged in the aeration tank 11, and a stirring paddle is arranged in the stirring tank 12.
More specifically, as shown in fig. 2, a gap is left between the front side of the flap 14 between the aeration tank 11 and the agitation tank 12 and the side wall of the primary coagulation sedimentation reaction tank 1 to facilitate circulation, and a gap is left between the rear side of the flap 14 between the agitation tank 12 and the static sedimentation tank 13 and the side wall of the primary coagulation sedimentation reaction tank 1 to facilitate circulation.
Specifically, as shown in fig. 3, a first side sewage draining outlet 31 and a second side sewage draining outlet are respectively arranged on two sides of a bottom sewage draining outlet of the mechanical stirring clarification tank 3.
Specifically, the inside of the defluorination resin tank 4 is sequentially provided with an activated carbon adsorbent particle layer, an iron sand filter material, a rare earth filter material and a special defluorination resin layer from bottom to top, and the thicknesses of the activated carbon adsorbent particle layer, the iron sand filter material, the rare earth filter material and the special defluorination resin layer are sequentially 100mm, 200mm and 700 mm.
More specifically, the particle size of the iron-carbon particles is 3 +/-2.0 mm, the particle size of the iron sand filter material is 2.0 +/-2.0 mm, the particle size of the rare earth filter material is 1.0 +/-0.5 mm, and the particle size of the special defluorination resin layer is 0.4 +/-0.2 mm.
Example 2:
a method for treating fluorine-containing industrial wastewater comprises the following steps:
(1) adjusting the pH value: pouring 5L of industrial wastewater with fluorine concentration of 150ppm into a primary coagulation sedimentation reaction tank 1, and adding calcium chloride to adjust the pH value of the industrial wastewater to 11.5;
(2) primary defluorination: according to Ca2+:F-Adding calcium chloride at a molar ratio of 5:1, stirring for 30min, adding calcium phosphate, and ensuring that the added calcium ions and the fluoride ions in the initial solution are Ca-based2+: calcium phosphate F-Adding the medicament at a ratio of 5:3:1, stirring for 30min, and finally separating the precipitate and the supernatant of the treated wastewater; in addition, during one defluorination period, the sediment is discharged into a sludge sedimentation tank 6 every 30min, and is discharged for 3min each time;
(3) secondary fluorine removal: introducing the supernatant of the wastewater obtained in the step (2) into a secondary coagulation sedimentation reaction tank 2, adding soluble calcium salt calcium chloride, stirring for 5-10min, adding flocculant polymeric ferric chloride (PFS), wherein the weight part ratio of the calcium chloride to the polymeric ferric chloride (PFS) is 3:1, performing flocculation sedimentation until the final concentration of fluoride ions is 10mg/L, and finally separating the supernatant subjected to sedimentation and defluorination treatment from the sediment; during the period, the obtained supernatant of the wastewater also flows back to the primary coagulation sedimentation reaction tank 1, and the backflow amount is 20 percent of the water inflow amount of the secondary coagulation sedimentation reaction tank 2; in addition, during the secondary defluorination, the sediment is discharged into a sludge sedimentation tank 6 every 30min, and is discharged for 3min each time;
(4) and (3) settling: introducing the supernatant of the wastewater obtained in the step (3) into a mechanical stirring clarification tank 3 for sedimentation clarification, operating the mechanical stirring clarification tank (3 for 1h, stopping the machine for 15min, intermittently operating the clarification tank to ensure stable effluent clarification, adding flocculating agents PAC and PAM to enable the wastewater to be better precipitated until the final concentration is less than 10mg/L for flocculation sedimentation, and allowing bottom sludge to enter a sludge sedimentation tank 6;
5) and (3) resin defluorination: introducing the supernatant of the wastewater obtained in the step 4) into a defluorination resin tank 4 from top to bottom, treating the wastewater by a special defluorination resin layer, a rare earth filter material, an iron sand filter material and an activated carbon adsorbent particle layer in sequence, keeping the retention time of the supernatant of the wastewater in the resin for 40min, introducing the treated wastewater into a clean water tank 5, and finally enabling the concentration of fluorine ions in the effluent to be less than 10ppm, preferably 2ppm, so as to meet the discharge standards of various regions and countries;
6) sludge treatment: PAC and PAM are added into the sludge sedimentation tank, which is beneficial to the flocculation sedimentation of the sludge and achieves the purposes of stable water outlet and quick flocculation; then, the sludge is transported outside after being subjected to plate-and-frame filter pressing, and the supernatant of the sludge sedimentation tank 6 flows back to the primary coagulation sedimentation reaction tank 1.
80g of calcium chloride is used for finally treating 5L of industrial wastewater with fluorine concentration of 150 ppm.
Example 3:
aiming at hydrofluoric acid soak solution wastewater in the photovoltaic semiconductor industry, the concentration of fluorine ions contained in the wastewater is 5 g/L.
A method for treating fluorine-containing industrial wastewater comprises the following steps:
(1) and (3) evaporation: after 1L of high fluorine-containing wastewater enters a PE raw water barrel, adding 13g of sulfuric acid with the content of 98% to improve the concentration of hydrofluoric acid in the wastewater, conveying the wastewater into an evaporation tower through a lining glue polytetrafluoroethylene pipeline, concentrating and purifying the hydrofluoric acid, changing the hydrofluoric acid wastewater into a hydrofluoric acid raw material, and enabling the generated hydrofluoric acid to be reused in industry, such as etching glass or removing oxides in the semiconductor industry, so as to realize the recycling of the wastewater; and finally, collecting about 400-600 ml of high-concentration hydrofluoric acid for recycling, and collecting evaporated water vapor through condensed water.
(2) Adjusting the pH value: pouring the condensed water obtained in the step (1) into a primary coagulation sedimentation reaction tank 1, and adding calcium chloride to adjust the pH value of the industrial wastewater to 11.5;
(3) primary defluorination: according to Ca2+:F-Adding calcium chloride at a molar ratio of 5:1, stirring for 30min, adding calcium phosphate, and ensuring that the added calcium ions and the fluoride ions in the initial solution are Ca-based2+: calcium phosphate F-Adding the medicament at a ratio of 5:3:1, stirring for 30min, and finally separating the precipitate and the supernatant of the treated wastewater; in addition, during one defluorination period, the sediment is discharged into a sludge sedimentation tank 6 every 30min, and is discharged for 3min each time;
(4) secondary fluorine removal: introducing the supernatant of the wastewater obtained in the step (2) into a secondary coagulation sedimentation reaction tank 2, adding soluble calcium salt calcium chloride, stirring for 5-10min, adding flocculant polyaluminum chloride (PAC), wherein the weight part ratio of the calcium chloride to the polyaluminum chloride (PAC) is 3:1, and performing flocculation sedimentation until the final concentration of fluoride ions is 10 mg/L; finally, separating the supernatant subjected to the defluorination treatment by precipitation from the precipitate; during the period, the obtained supernatant of the wastewater also flows back to the primary coagulation sedimentation reaction tank 1, and the backflow amount is 20 percent of the water inflow amount of the secondary coagulation sedimentation reaction tank 2; in addition, during the secondary defluorination, the sediment is discharged into a sludge sedimentation tank 6 every 30min, and is discharged for 3min each time;
(5) and (3) settling: introducing the supernatant of the wastewater obtained in the step (3) into a mechanical stirring clarification tank 3 for sedimentation clarification, operating the mechanical stirring clarification tank 3 for 1h, stopping the machine for 15min, intermittently operating the clarification tank to ensure that the effluent is clarified stably, adding flocculating agents PAC and PAM to enable the wastewater to be better precipitated until the final concentration is less than 10mg/L for flocculation sedimentation, and allowing the bottom sludge to enter a sludge sedimentation tank 6;
(6) and (3) resin defluorination: and (3) introducing the supernatant of the wastewater obtained in the step (4) into a defluorination resin tank (4) from top to bottom, treating the wastewater by a special defluorination resin layer, a rare earth filter material, an iron sand filter material and an activated carbon adsorbent particle layer in sequence, keeping the retention time of the supernatant of the wastewater in the resin for 40min, allowing the treated wastewater to enter a clean water tank (5), and finally making the concentration of fluorine ions in the effluent less than 10ppm, optimally reaching 5ppm, so as to meet the discharge standards of various regions and countries.
(7) Sludge treatment: PAC and PAM are added into the sludge sedimentation tank, which is beneficial to the flocculation sedimentation of the sludge and achieves the purposes of stable water outlet and quick flocculation; then, the sludge is transported outside after being subjected to plate-and-frame filter pressing, and the supernatant of the sludge sedimentation tank 6 flows back to the primary coagulation sedimentation reaction tank 1.
As the condensed water is basically evaporated water vapor and contains few fluorine ions, the calcium chloride used in the wastewater is about 40g, and the obtained 400-600 ml concentrated hydrofluoric acid can be recycled.
Comparative example 1: the fluorine-containing concentration of certain 5L of industrial wastewater is 150ppm, and the specific treatment steps are as follows:
(1) adjusting the pH value: pouring 5L of industrial wastewater into a primary coagulation sedimentation reaction tank 1, and adding calcium chloride to adjust the pH value of the industrial wastewater to 11.5;
(2) primary defluorination: according to Ca2+:F-Adding calcium chloride at a molar ratio of 3:1, stirring for 30min, adding calcium phosphate, and ensuring that the added calcium ions and the fluoride ions in the initial solution are Ca-based2+: calcium phosphate: f-Adding a medicament in a molar ratio of 3:3:1, stirring for 30min, and separating the precipitate and the supernatant of the treated wastewater;
(3) secondary fluorine removal: introducing the supernatant of the wastewater obtained in the step (2) into a secondary coagulation sedimentation reaction tank 2, continuously adding calcium chloride, and separating the supernatant subjected to sedimentation defluorination from the sediment;
(4) entering a secondary sedimentation tank: and (3) separating sludge and supernatant by gravity without stirring in the secondary sedimentation tank, allowing the supernatant to enter a final water outlet tank, monitoring the concentration of fluorine ions in the outlet water, performing repeated experiments, and determining that the optimal effect is only 18ppm and cannot meet the discharge standard of less than 10ppm, thereby determining that the outlet water is unqualified.
(5) A sludge sedimentation tank: introducing the sludge in the steps (2), (3) and (4) into a sludge sedimentation tank, separating supernatant subjected to sedimentation and defluorination treatment from sediment, finally carrying out plate-and-frame filter pressing on the sludge in the sludge sedimentation tank, and then transporting the sludge out, wherein the supernatant in the sludge sedimentation tank flows back to a primary reaction tank; because no PAC or PFS flocculating agent is added, the flocculation performance of the sediment is poor, the sedimentation effect is poor, the sludge stratification is not obvious, the flocculation effect of the produced sludge is poor, the sludge sedimentation tank is turbid, the supernatant and the bottom sludge are not obvious in stratification, and the sludge filter pressing is not facilitated.
154g of pharmaceutical calcium chloride for finally treating 5L of industrial wastewater with fluorine concentration of 150ppm is 74g more than that of example 2.
Comparative example 2
1L of wastewater with fluorine concentration of 150ppm in a certain industry, only calcium chloride is added by applying the currently common chemical fluorine removal method according to the chemical reaction Ca2++2F-＝CaF2↓
According to the chemical equation, Ca2+:F-After adding 4g of calcium chloride at a ratio of 1:2 and stirring for 30 minutes, the residual fluoride ion in the water was measured and the same procedure was repeated to obtain the following data:
after a plurality of experiments, the concentration of the fluoride ions is basically maintained at 30% and does not decrease, because the fluoride ions in the water cannot be effectively removed after being wrapped by calcium fluoride precipitates, the effect of removing the fluoride ions by a single chemical reaction cannot reach less than 10ppm, and finally the fluoride ions cannot reach the standard.
As can be seen from the comparative example 1, the dosage of the additive is too small, the terminal resin is not used for removing fluorine, and flocculants such as PAC or PFS are not added, the final effluent reaches the requirement of less than 10ppm, and meanwhile, the common sedimentation tank cannot play a good sedimentation property for sediments with poor flocculation performance, so that the gravity separation of supernatant and bottom sediments is not good, and the sedimentation effect is not as good as that of a mechanical stirring sedimentation tank.
As can be seen from the above comparative example 2, the defluorination performed by only the conventional chemical reaction has an obvious effect at the beginning, and can generate calcium fluoride precipitate, the more the calcium fluoride precipitate is added later, the lower the defluorination effect is, and finally, no fluorine ions are removed basically, and finally, the fluorine ions are not reduced any more when being maintained at about 30ppm, and the emission standard can not be met.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
Claims (10)
1. The utility model provides a fluorine-containing industrial wastewater treatment system which characterized in that: comprises a primary coagulation sedimentation reaction tank (1), a secondary coagulation sedimentation reaction tank (2), a mechanical stirring clarification tank (3), a defluorination resin tank (4) and a clean water tank (5) which are connected in sequence; the primary coagulation sedimentation reaction tank (1), the secondary coagulation sedimentation reaction tank (2) and the mechanical stirring clarification tank (3) are arranged in a sequential fall manner, so that the wastewater is automatically and sequentially treated in the primary coagulation sedimentation reaction tank (1), the secondary coagulation sedimentation reaction tank (2) and the mechanical stirring clarification tank (3); the primary coagulation sedimentation reaction tank (1), the secondary coagulation sedimentation reaction tank (2) and the mechanical stirring clarification tank (3) are also connected with a sludge sedimentation tank (6) through a sludge pump, and the middle lower part of the secondary coagulation sedimentation reaction tank (2) is also connected with the primary coagulation sedimentation reaction tank (1) through a water pump; the mechanical stirring clarification tank (3) is connected with the defluorination resin tank (4) through a water pump, and the defluorination resin tank (4) is connected with the clean water tank (5) through a water pump.
2. The fluorine-containing industrial wastewater treatment system according to claim 1, wherein: be equipped with folded plate (14) of 2 vertical settings in one-level coagulating sedimentation reaction tank (1), folded plate (14) divide into aeration tank (11), agitator tank (12) and the triplex case structure of quiet caisson (13) that communicate in proper order from a left side to the right side with one-level coagulating sedimentation reaction tank (1) inside, and form S type flow path from aeration tank (11) to quiet caisson (13) between, be equipped with the aeration pipe in aeration tank (11), be equipped with the stirring rake in agitator tank (12).
3. The fluorine-containing industrial wastewater treatment system according to claim 1, wherein: and a first side sewage draining outlet (31) and a second side sewage draining outlet are respectively arranged on two sides of a bottom sewage draining outlet of the mechanical stirring clarification tank (3).
4. The fluorine-containing industrial wastewater treatment system according to claim 1, wherein: the activated carbon adsorbent particle layer, the iron sand filter material, the rare earth filter material and the special fluorine-removing resin layer are sequentially arranged inside the fluorine-removing resin tank (4) from bottom to top, and the thicknesses of the activated carbon adsorbent particle layer, the iron sand filter material, the rare earth filter material and the special fluorine-removing resin layer are 80-100 mm, 180-200 mm and 650-700 mm sequentially.
5. The fluorine-containing industrial wastewater treatment system according to claim 4, wherein: the particle size of the iron-carbon particles is 3-5 mm, the particle size of the iron sand filter material is 2.0-3.0 mm, the particle size of the rare earth filter material is 1.0-0.5 mm, and the particle size of the special defluorination resin layer is 0.4-0.6 mm.
6. A fluorine-containing industrial wastewater treatment method is characterized in that: the method comprises the following steps:
1) adjusting the pH value: adding an alkaline regulator into the primary coagulation sedimentation reaction tank (1), and adjusting the pH value to be 11 or above;
2) primary defluorination: continuously feeding the mixture into a first-stage coagulation sedimentation reaction tank (1) according to the molar ratio Ca2+:F-Adding soluble calcium salt into the mixture 1, stirring for 30-40min, and adding the soluble calcium salt to promote precipitation; in addition, discharging the sediment into a sludge sedimentation tank (6) every 30-60 min, wherein the sediment is discharged for 3-5min each time;
3) secondary fluorine removal: introducing the supernatant of the wastewater obtained in the step 2) into a secondary coagulation sedimentation reaction tank (2), adding soluble calcium salt, stirring for 5-10min, and adding a flocculating agent until the final concentration of fluoride ions is 10mg/L for flocculation sedimentation; in addition, discharging the sediment into a sludge sedimentation tank (6) every 30-60 min, wherein the sediment is discharged for 3-5min each time; the obtained supernatant of the wastewater also flows back to the primary coagulation sedimentation reaction tank (1);
4) and (3) settling: introducing the supernatant of the wastewater obtained in the step 3) into a mechanical stirring clarification tank (3) for sedimentation clarification, operating the mechanical stirring clarification tank (3) for 1h, stopping the machine for 10-20 min, intermittently operating the sedimentation tank to ensure that the effluent is clarified and stable, simultaneously adding a flocculating agent for sedimentation, and discharging the bottom sludge into a sludge sedimentation tank (6);
5) and (3) resin defluorination: introducing the supernatant of the wastewater obtained in the step 4) into a defluorination resin tank (4), keeping the retention time of the supernatant of the wastewater in resin for 30-40min, and introducing the treated wastewater into a clean water tank (5);
6) sludge treatment: and (3) carrying out filter pressing on the sludge discharged into the sludge sedimentation tank (6) by a plate frame and then transporting the sludge outwards, and refluxing the supernatant of the sludge sedimentation tank (6) to the primary coagulation sedimentation reaction tank (1).
7. The fluorine-containing industrial wastewater treatment method according to claim 6, characterized in that: the primary coagulation sedimentation reaction tank (1) adopts a folded plate triple box structure, the triple box comprises an aeration box (11), a stirring box (12) and a static settling tank (13) which are sequentially communicated, and wastewater firstly passes through the aeration box (11) and is aerated in the aeration box to realize stirring at the same time; then enters a stirring box (12) and is stirred under the action of a stirring paddle; finally, the sludge enters a static settling tank (13) to precipitate the generated calcium fluoride and the sludge is discharged into a sludge settling tank (6) intermittently.
8. The fluorine-containing industrial wastewater treatment method according to claim 6, characterized in that: the reflux amount in the step 3) is 15-20% of the water inflow amount of the secondary coagulation sedimentation reaction tank (2).
9. The fluorine-containing industrial wastewater treatment method according to claim 6, characterized in that: in the step 1), before adding calcium chloride, adding inorganic acid to adjust the pH of the wastewater to 6-8.
10. The fluorine-containing industrial wastewater treatment method according to claim 6, characterized in that: the method also includes adding acid to the wastewater to form hydrofluoric acid and evaporating the hydrofluoric acid prior to adjusting the pH.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110121110.3A CN112811669B (en) | 2021-01-28 | 2021-01-28 | Fluorine-containing industrial wastewater treatment system and treatment method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110121110.3A CN112811669B (en) | 2021-01-28 | 2021-01-28 | Fluorine-containing industrial wastewater treatment system and treatment method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112811669A true CN112811669A (en) | 2021-05-18 |
| CN112811669B CN112811669B (en) | 2022-09-30 |
Family
ID=75859972
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110121110.3A Active CN112811669B (en) | 2021-01-28 | 2021-01-28 | Fluorine-containing industrial wastewater treatment system and treatment method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112811669B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115340221A (en) * | 2022-09-14 | 2022-11-15 | 深圳市环境科学研究院 | Deep defluorination treatment process and recycling system |
| CN117238389A (en) * | 2023-11-14 | 2023-12-15 | 江苏海峡环保科技发展有限公司 | Fluorine-containing wastewater treatment system and method based on intelligent dosing |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN203498191U (en) * | 2013-08-05 | 2014-03-26 | 河海大学 | Ultrafiltration combination device for removing fluoride ions in groundwater |
| WO2017148229A1 (en) * | 2016-03-01 | 2017-09-08 | 大唐环境产业集团股份有限公司 | Low-sludge-production desulfurization wastewater treatment apparatus and method |
| CN108328786A (en) * | 2018-01-17 | 2018-07-27 | 湖南博世科环保科技有限公司 | A kind of water treatment facilities and method for treating water |
| CN111268830A (en) * | 2020-04-01 | 2020-06-12 | 江苏中电创新环境科技有限公司 | System and process for advanced treatment and recycling of fluorine-containing wastewater in electronic industry |
| CN111777232A (en) * | 2020-08-05 | 2020-10-16 | 新能凤凰（滕州）能源有限公司 | Production wastewater defluorination treatment system and method |
-
2021
- 2021-01-28 CN CN202110121110.3A patent/CN112811669B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN203498191U (en) * | 2013-08-05 | 2014-03-26 | 河海大学 | Ultrafiltration combination device for removing fluoride ions in groundwater |
| WO2017148229A1 (en) * | 2016-03-01 | 2017-09-08 | 大唐环境产业集团股份有限公司 | Low-sludge-production desulfurization wastewater treatment apparatus and method |
| CN108328786A (en) * | 2018-01-17 | 2018-07-27 | 湖南博世科环保科技有限公司 | A kind of water treatment facilities and method for treating water |
| CN111268830A (en) * | 2020-04-01 | 2020-06-12 | 江苏中电创新环境科技有限公司 | System and process for advanced treatment and recycling of fluorine-containing wastewater in electronic industry |
| CN111777232A (en) * | 2020-08-05 | 2020-10-16 | 新能凤凰（滕州）能源有限公司 | Production wastewater defluorination treatment system and method |
Non-Patent Citations (1)
| Title |
|---|
| 中国稀土学会: "《中国稀土科技进展》", 30 November 2000, 冶金工业出版社 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115340221A (en) * | 2022-09-14 | 2022-11-15 | 深圳市环境科学研究院 | Deep defluorination treatment process and recycling system |
| CN117238389A (en) * | 2023-11-14 | 2023-12-15 | 江苏海峡环保科技发展有限公司 | Fluorine-containing wastewater treatment system and method based on intelligent dosing |
| CN117238389B (en) * | 2023-11-14 | 2024-01-30 | 江苏海峡环保科技发展有限公司 | Fluorine-containing wastewater treatment system and method based on intelligent dosing |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112811669B (en) | 2022-09-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109626715B (en) | Method for reducing ammonia load in leachate treatment biochemical system | |
| CA2707011C (en) | Method for removing silica from evaporator concentrate | |
| CN112811669B (en) | Fluorine-containing industrial wastewater treatment system and treatment method thereof | |
| CN113003846B (en) | Zero-emission treatment process and system for sewage with high salt content and high COD (chemical oxygen demand) | |
| CN111892142A (en) | Silicon removal agent, silicon removal and hardness removal sewage treatment system and method | |
| CN105036408A (en) | Treatment method of wastewater containing high-concentration active silicon | |
| KR20110131535A (en) | The method and appuratus of removing total nitrogen and phosphate in sewage and wastewater using precipitation-agent of rapidity for coagulation an flocculation | |
| CN111777220A (en) | Novel softening treatment method for high-salinity and high-permanent-hardness wastewater | |
| CN212450783U (en) | Sewage treatment system for removing silicon and hardness | |
| CN108529788B (en) | Purifying method and device for bromine extraction waste liquid | |
| JP2013119081A (en) | Treatment method and treatment apparatus for phosphorus-containing wastewater | |
| CN117023919A (en) | Multistage treatment system and multistage treatment process for gas field produced water | |
| CN210528624U (en) | Wastewater treatment system containing electrolytic manganese slag | |
| CN115572028B (en) | Method and device for treating phosphorus-containing fluorine-containing wastewater | |
| CN111302536A (en) | Treatment system and treatment process for wastewater containing fluorine and phosphorus | |
| CN111099773A (en) | Desulfurization wastewater treatment method and system | |
| CN111099774A (en) | Desulfurization wastewater treatment method and system | |
| CN106430771B (en) | salt separation system and salt separation method | |
| CN214612016U (en) | Deep water purification device for realizing magnetic coagulation sedimentation by utilizing magnetic resin | |
| CN107445347A (en) | The processing system and processing method of a kind of phosphorus-containing wastewater | |
| CN213416607U (en) | Sewage treatment device system | |
| CN212403721U (en) | Desulfurization wastewater treatment system | |
| CN211871618U (en) | Device for treating desulfurization wastewater by composite method | |
| CN207451807U (en) | Desulphurization for Coal-fired Power Plant waste water integrates fluoride-removing equipment | |
| JP3339352B2 (en) | Sludge treatment method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |