CN114804400A - System and process for removing fluorine after biochemical treatment of coking wastewater - Google Patents
System and process for removing fluorine after biochemical treatment of coking wastewater Download PDFInfo
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- CN114804400A CN114804400A CN202210252389.3A CN202210252389A CN114804400A CN 114804400 A CN114804400 A CN 114804400A CN 202210252389 A CN202210252389 A CN 202210252389A CN 114804400 A CN114804400 A CN 114804400A
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- 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
- C02F1/5245—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents using basic salts, e.g. of aluminium and iron
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- 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
- C02F1/54—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using organic material
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- C02F1/58—Treatment of water, waste water, or sewage by removing specified dissolved compounds
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Abstract
A system and a process for removing fluorine from coking wastewater after biochemical treatment aim at the condition that the concentration of fluorine ions in effluent after biochemical treatment of coking wastewater is high, the limitation of the traditional fluorine removal process is broken on the basis of not influencing the removal of other pollutants, and fluorine can be directly removed in advance without coagulation reaction. The invention utilizes the synergistic effect of chemical precipitation, coagulating sedimentation and excess sludge adsorption to remove fluorine in the fluorine removal tank. Meanwhile, in the selection of the defluorinating agent, the application of single calcium salt is broken, and calcium salt is added into the defluorinating tank to jointly use other inorganic salts, so that new fluorine-containing compounds which are more difficult to dissolve are generated, and the chemical precipitation time is shortened; in addition, a small amount of excess sludge in the effluent of the secondary sedimentation tank is defluorinated by the actions of rolling, sweeping, adsorbing and the like. Meanwhile, the formed chemical precipitation can be accelerated to coagulate due to the good adsorption performance of the excess sludge, and the formed clusters have better precipitation performance in water and better defluorination effect.
Description
Technical Field
The invention relates to a coking wastewater treatment technology, in particular to a system and a process for removing fluorine after biochemical treatment of coking wastewater.
Background
Fluorine in nature exists mostly in a compound state, mainly exists in fluorite, apatite and cryolite, and is widely applied to industries such as smelting, chemical fertilizers, glass manufacturing and the like. During the coking process of the coal, the released fluorine-containing substances exist in the residual ammonia water in the form of fluorides, and the concentration is about 30-50 mg/L. In addition, in the production process of coumarone, if BF3 is used as a polymerization catalyst, fluorine is easy to be brought into discharged wastewater. The national standard strictly regulates the fluorine content in coking wastewater. Therefore, the research on the defluorination process of the coking wastewater is always a subject of wide attention in the field of environmental protection.
For decades, a great deal of research on defluorination has been carried out at home and abroad, and the research on the technology and the basic theory has also made a certain progress. At present, techniques which can be practically used include an adsorption method, an electrocoagulation method, a Reverse Osmosis (R/O) method, an ion exchange method, a chemical precipitation method, a coagulation sedimentation method, and the like. The adsorption method is a water treatment process for absorbing and separating pollutants in water by utilizing porous solid phase substances; the electrocoagulation method is a novel drinking water defluorination technology researched in recent years, and mainly utilizes the electrolysis principle to carry out defluorination on water; the reverse osmosis membrane separation technology is used for treating fluorine-containing wastewater and is a technology for separating molecules from fluorine ions under the action of a semipermeable membrane; the ion exchange method utilizes the ion exchange effect of anion exchange resin to achieve the aim of removing fluorine; the chemical precipitation method is to form fluoride precipitate by adding calcium salt and the like, or to coprecipitate fluoride on the precipitate, and then to remove fluoride ions by solid-liquid separation; coagulating sedimentation defluorination adopts the process of adding substances with coagulation ability or generating precipitation with fluoride into water to form a large amount of colloid substances or precipitation, coagulating or precipitating the fluoride, and then filtering to remove fluorine ions from the water.
The ion exchange method has high cost and strict requirements on the water quality of raw water; the electrocoagulation and reverse osmosis methods have complex processes and large power consumption; the adsorption method has low adsorption capacity and small water treatment amount, and is difficult to realize industrialization. Thus, the most commonly used methods for the removal of fluorine from industrial waste water are chemical precipitation and coagulation sedimentation.
The main process for removing fluorine from coking wastewater at present is that after biochemical treatment, coking wastewater is subjected to secondary sedimentation (effluent water after biochemical treatment is separated into secondary sedimentation tank effluent water and secondary sedimentation tank sludge in a secondary sedimentation tank) + coagulation reaction (effluent water from a secondary sedimentation tank is subjected to coagulation reaction in a coagulation reaction tank, suspended matters, colloids and other substances capable of flocculating in the wastewater are coagulated into 'floccules') and then is subjected to coagulation sedimentation (wastewater after flocculation is subjected to solid-liquid separation in the coagulation sedimentation tank, the 'floccules' are settled into slurry at the bottom of sedimentation equipment, and effluent water from the top is the coagulation sedimentation effluent water) + removing fluorine (effluent water and fluorine-removing sludge are separated from the coagulation sedimentation tank effluent water in a fluorine-removing reaction tank by a chemical sedimentation method). The traditional chemical precipitation method generally adopts a calcium salt precipitation method, namely lime is added into the wastewater to enable fluorine ions and calcium ions to generate CaF 2 Precipitating and removing. The process has the advantages of simple method, convenient treatment, low cost and the like, but has the defects that the treated effluent hardly meets the subsequent treatment requirement, the sludge is slowly settled and is difficult to dehydrate, and the like.
Disclosure of Invention
Aiming at the defects or shortcomings in the prior art, the invention provides a system and a process for removing fluorine after biochemical treatment of coking wastewater.
The technical solution of the invention is as follows:
the utility model provides a defluorination system after coking wastewater biochemical treatment for the experimental study of defluorination technology after coking wastewater biochemical treatment, treat that the defluorination water is coking wastewater biochemical treatment unit goes out water or coking wastewater biochemical treatment back two heavy ponds go out water, its characterized in that, including treating the defluorination water holding reservoir, the input port of treating the defluorination water holding reservoir is the import of treating the defluorination water, the output port of treating the defluorination water holding reservoir passes through the input port of water pump connection defluorination reaction tank, the input port of coagulation reaction tank is connected to the output port of defluorination reaction tank, the top of defluorination reaction tank is provided with first agitator, defluorination agent dosing tank is connected to the defluorination reaction tank, the top of coagulation reaction tank is provided with the second agitator, the coagulation reaction tank connects the coagulation dosing tank, the input port of swash plate sedimentation tank is connected to the output port of coagulation reaction tank, the delivery outlet of swash plate sedimentation tank connects the defluorination box, the water outlet tank, the inclined plate sedimentation tank, the coagulation reaction tank and the defluorination reaction tank are respectively connected with a drainage tank.
Treat that the input port in fluorine removal water holding vessel is provided with the filter screen, the bottom of treating fluorine removal water holding vessel is provided with first valve, treat fluorine removal water holding vessel with be provided with the second valve between the water pump, the water pump with be provided with the flowmeter between the fluorine removal reaction tank, the flowmeter with be provided with the third valve between the water pump, the third valve with be provided with the manometer on the pipeline between the water pump, fluorine removal reaction tank connects through the fifth valve fluorine removal agent dosing tank, fluorine removal reaction tank with the tee bend node has on the communicating pipe way in coagulation reaction tank, the first logical intercommunication of tee bend node the delivery outlet in fluorine removal reaction tank, the second leads to the input port in coagulation reaction tank, the third is through sixth valve intercommunication the dosing tank thoughtlessly congeals.
The defluorination reaction tank is connected with the water drainage tank through a fourth valve arranged at the bottom of the defluorination reaction tank, the coagulation reaction tank is connected with the water drainage tank through a seventh valve arranged at the bottom of the coagulation reaction tank, and the inclined plate sedimentation tank is connected with the water drainage tank through an eighth valve arranged at the bottom of the inclined plate sedimentation tank.
The bottom of water drainage tank is provided with the tenth valve, the bottom of play water tank is provided with the ninth valve.
The utility model provides a coking wastewater biochemical treatment back defluorination system, a serial communication port, including defluorination reaction tank, the input port of defluorination reaction tank is that two sink ponds go out water and directly link interface or biochemical treatment unit play water and directly link the interface, the output port of defluorination reaction tank is connected and is thoughtlessly congealed the reaction tank, the top of defluorination reaction tank is provided with first agitator, defluorination agent dosing tank is connected to the defluorination reaction tank.
The defluorination reaction tank is connected through a fifth valve, the defluorination agent dosing box, the defluorination reaction tank with the coagulation reaction tank communicating pipe has a tee joint node, the first intercommunication of tee joint node the delivery outlet of the defluorination reaction tank, the second intercommunication the input port of the coagulation reaction tank, the third tee joint pass through a sixth valve intercommunication coagulation dosing box, the top of the coagulation reaction tank is provided with a second stirrer, the input port of the sedimentation tank is connected to the delivery outlet of the coagulation reaction tank, the delivery outlet of the sedimentation tank is a follow-up processing link interface.
A defluorination process after biochemical treatment of coking wastewater is characterized in that a defluorination agent is directly added into a secondary sedimentation tank or a defluorination reaction tank without coagulating sedimentation after biochemical treatment of coking wastewater, and the chemical sedimentation, coagulating sedimentation, residual sludge adsorption and rolling sweeping synergistic action of the defluorination agent are comprehensively utilized to simultaneously defluorinate.
The defluorination reaction comprises a refractory fluorine-containing compound generated by combining calcium ions with other inorganic salts so as to shorten the chemical precipitation time.
A defluorination process after biochemical treatment of coking wastewater is characterized by comprising the following steps:
step 1, a secondary sedimentation tank directly connected with a coking wastewater biochemical treatment unit is used as a defluorination reaction tank to directly defluorinate effluent of the coking wastewater biochemical treatment unit, or the defluorination reaction tank is inserted between the secondary sedimentation tank and a coagulation reaction tank to defluorinate effluent of the secondary sedimentation tank after biochemical treatment of the coking wastewater;
step 2, adding a defluorinating agent into the defluorination reaction tank for chemical precipitation, so that fluorine ions in water generate indissolvable fluorine-containing compounds, and then conveying the effluent of the defluorination reaction tank to a coagulation reaction tank;
and 4, conveying the supernatant formed by standing the water in the sedimentation tank to a subsequent treatment link.
The step 3 comprises adding polyacrylamide PAM to carry out flocculation reaction.
The defluorinating agent comprises calcium hydroxide.
The aluminum salt is polyaluminum chloride and/or polyaluminum sulfate.
The invention has the following technical effects: the invention relates to a system and a process for removing fluorine from coking wastewater after biochemical treatment, which aims at the condition that the concentration of fluorine ions in effluent after biochemical treatment of coking wastewater is higher, breaks through the limitation of the traditional fluorine removal process on the basis of not influencing the removal of other pollutants, and can directly remove fluorine in advance without coagulation reaction. The invention utilizes the synergistic effect of chemical precipitation, coagulating sedimentation and excess sludge adsorption to remove fluorine in the fluorine removal tank. Meanwhile, in the selection of the defluorinating agent, the application of single calcium salt is broken, and calcium salt is added into the defluorinating tank to jointly use other inorganic salts, so that new fluorine-containing compounds which are more difficult to dissolve are generated, and the chemical precipitation time is shortened; in addition, a small amount of excess sludge in the effluent of the secondary sedimentation tank is defluorinated by the actions of rolling, sweeping, adsorbing and the like. Meanwhile, the formed chemical precipitation can be accelerated to coagulate due to the good adsorption performance of the excess sludge, and the formed clusters have better precipitation performance in water and better defluorination effect.
Drawings
FIG. 1 is a schematic structural diagram of a defluorination system after biochemical treatment of coking wastewater in a laboratory.
FIG. 2 is a schematic structural diagram of a defluorination system after biochemical treatment of coking wastewater in a certain coking plant.
The reference numbers are listed below: 1-an inlet of water to be subjected to fluorine removal (the water to be subjected to fluorine removal is effluent of coking wastewater after biochemical treatment or effluent of a secondary sedimentation tank of the coking wastewater after biochemical treatment); 2-filtering the net; 3-a storage pool for water to be defluorinated; 4-a first valve; 5-a second valve; 6, a water pump; 7-a pressure gauge; 8-a third valve; 9-a flow meter; 10-a defluorination reaction tank; 11-a first stirrer; 12-a fourth valve; 13-a fifth valve; 14-a fluorine removing agent dosing box; 15-coagulation dosing box; 16-a sixth valve; 17-a coagulation reaction tank; 18-a second stirrer; 19-a seventh valve; 20-inclined plate sedimentation tank; 21-eighth valve; 22-water outlet tank; 23-a ninth valve; 24-a drainage channel; 25-tenth valve; 26-a sedimentation tank; 27-a subsequent processing link interface; 28-secondary sedimentation tank water outlet direct connection interface or biochemical treatment unit water outlet direct connection interface.
Detailed Description
The invention is explained below with reference to the figures (fig. 1-2) and examples.
FIG. 1 is a schematic structural diagram of a defluorination system after biochemical treatment of coking wastewater in a laboratory. Referring to fig. 1, a defluorination system after biochemical treatment of coking wastewater, which is used for experimental research of defluorination process after biochemical treatment of coking wastewater, wherein the water to be defluorinated is effluent of a biochemical treatment unit of coking wastewater or effluent of a secondary sedimentation tank after biochemical treatment of coking wastewater, and comprises a storage tank 3 of the water to be defluorinated, an input port 1 of the storage tank 3 of the water to be defluorinated is an inlet of the water to be defluorinated, an output port of the storage tank 3 of the water to be defluorinated is connected with an input port of a defluorination reaction tank 10 through a water pump 6, an output port of the defluorination reaction tank 10 is connected with an input port of a coagulation reaction tank 17, a first stirrer 11 is arranged at the top of the defluorination reaction tank 10, a defluorination agent dosing tank 14 is connected with the defluorination reaction tank 10, a second stirrer 18 is arranged at the top of the coagulation reaction tank 17, the coagulation reaction tank 17 is connected with the coagulation dosing tank 18, an output port of the coagulation reaction tank 17 is connected with an input port of an inclined plate sedimentation tank 20, the outlet port of the inclined plate sedimentation tank 20 is connected with a water outlet tank 22, and the water outlet tank 22, the inclined plate sedimentation tank 20, the coagulation reaction tank 17 and the defluorination reaction tank 10 are respectively connected with a water drainage tank 24.
A filter screen 2 is arranged at an input port 1 of the storage pool 3 for the water to be defluorinated, a first valve 4 is arranged at the bottom of the storage pool 3 for the water to be defluorinated, a second valve 5 is arranged between the storage tank 3 for the water to be defluorinated and the water pump 6, a flowmeter 9 is arranged between the water pump 6 and the defluorination reaction tank 10, a third valve 8 is arranged between the flowmeter 9 and the water pump 6, a pressure gauge 7 is arranged on a pipeline between the third valve 8 and the water pump 6, the defluorination reaction tank 10 is connected with the defluorination agent dosing tank 14 through a fifth valve 13, a three-way joint is arranged on a communication pipeline between the defluorination reaction tank 10 and the coagulation reaction tank 17, the first channel of the three-way joint is communicated with the output port of the defluorination reaction tank 10, the second channel is communicated with the input port of the coagulation reaction tank 17, and the third channel is communicated with the coagulation dosing tank 15 through a sixth valve 16.
The defluorination reaction tank 10 is connected with the drainage groove 24 through a fourth valve 12 arranged at the bottom of the defluorination reaction tank, the coagulation reaction tank 17 is connected with the drainage groove 24 through a seventh valve 19 arranged at the bottom of the coagulation reaction tank, and the inclined plate sedimentation tank 20 is connected with the drainage groove 24 through an eighth valve 21 arranged at the bottom of the inclined plate sedimentation tank. The bottom of the drainage channel 24 is provided with a tenth valve 25, and the bottom of the outlet tank 22 is provided with a ninth valve 23.
FIG. 2 is a schematic structural diagram of a defluorination system after biochemical treatment of coking wastewater in a certain coking plant. Referring to fig. 2, a defluorination system after biochemical treatment of coking wastewater, including defluorination reaction tank 10, the input port of defluorination reaction tank 10 is that two heavy ponds go out water directly to connect interface or biochemical treatment unit play water directly to connect interface 28, the output port of defluorination reaction tank 10 is connected and is thoughtlessly congealed reaction tank 17, the top of defluorination reaction tank 10 is provided with first agitator 11, defluorination reaction tank 10 connects defluorination agent dosing tank 14. The defluorination reaction tank 10 is connected through a fifth valve 13 the defluorination agent dosing box 14, the defluorination reaction tank 10 with the communicating pipe of the coagulation reaction tank 17 is provided with a tee joint, the first intercommunication of the tee joint is the delivery outlet of the defluorination reaction tank 10, the second intercommunication the input port of the coagulation reaction tank 17, the third valve 16 intercommunication coagulation dosing box 15 is passed through to the third, the top of the coagulation reaction tank 17 is provided with a second stirrer 18, the input port of the sedimentation tank 26 is connected to the delivery outlet of the coagulation reaction tank 17, the delivery outlet of the sedimentation tank 26 is a follow-up processing link interface 27.
A defluorination process after biochemical treatment of coking wastewater, a defluorination agent is directly added into a secondary sedimentation tank or a defluorination reaction tank without coagulating sedimentation, and the chemical sedimentation and coagulating sedimentation of the defluorination agent and the synergistic action of residual sludge adsorption and rolling sweeping are comprehensively utilized to simultaneously defluorinate. The defluorination reaction comprises a refractory fluorine-containing compound generated by combining calcium ions with other inorganic salts so as to shorten the chemical precipitation time.
A defluorination process after biochemical treatment of coking wastewater comprises the following steps: step 1, a secondary sedimentation tank directly connected with a coking wastewater biochemical treatment unit is used as a defluorination reaction tank to directly defluorinate effluent of the coking wastewater biochemical treatment unit, or the defluorination reaction tank is inserted between the secondary sedimentation tank and a coagulation reaction tank to defluorinate effluent of the secondary sedimentation tank after biochemical treatment of the coking wastewater; step 2, adding a defluorinating agent into the defluorination reaction tank for chemical precipitation, so that fluorine ions in water generate indissolvable fluorine-containing compounds, and then conveying the effluent of the defluorination reaction tank to a coagulation reaction tank; step 3, adding a coagulant into the coagulation reaction tank, wherein the coagulant comprises aluminum salt, aluminum ions and fluorine ions generate hydroxyl aluminum fluoride complex precipitate and an aluminum salt hydrolysis intermediate product, alum blossom in the aluminum salt hydrolysis intermediate product plays roles in coordination exchange, physical adsorption and net capture on the fluorine ions, and then conveying effluent of the coagulation reaction tank to the precipitation tank; and 4, conveying the supernatant formed by standing the water in the sedimentation tank to a subsequent treatment link. The defluorinating agent comprises calcium hydroxide. The aluminum salt is polyaluminum chloride and/or polyaluminum sulfate. The step 3 comprises adding polyacrylamide PAM to carry out flocculation reaction.
The invention provides a treatment process of fluorinion in effluent of coking wastewater after biochemical treatment. The process of the invention is a new process for directly carrying out defluorination treatment in a secondary sedimentation tank or a defluorination tank aiming at the condition that the effluent water after the biochemical treatment of the coking wastewater has higher fluorine ion concentration and breaking the limitation of the traditional defluorination process on the basis of not influencing the removal of other pollutants. The invention removes fluorine by utilizing the synergistic effect of chemical precipitation, coagulating sedimentation and residual sludge adsorption in a secondary sedimentation tank or a fluorine removal tank behind the secondary sedimentation tank. Meanwhile, in the selection of the defluorinating agent, the application of single calcium salt is broken, and calcium salt is added into a secondary sedimentation tank or a defluorinating tank to jointly use other inorganic salts, so that new fluorine-containing compounds which are more difficult to dissolve are generated, and the chemical precipitation time is shortened; in addition, a small amount of excess sludge in the effluent of the secondary sedimentation tank is defluorinated through the actions of rolling sweeping, adsorption and the like. Meanwhile, the formed chemical precipitation can be accelerated to coagulate due to the good adsorption performance of the excess sludge, and the formed clusters have better precipitation performance in water and better defluorination effect.
In order to achieve the purpose, the invention adopts the following technical scheme:
a process for removing fluorine from the coking sewage after biochemical reaction features that the coagulating-depositing pool is not used after biochemical reaction, the fluorine removing agent is directly added to secondary deposition pool or the reaction pool after secondary deposition pool for chemical deposition and coagulating deposition, the residual sludge is swept and adsorbed for removing fluorine, the water after reaction is deposited in inclined-plate deposition pool, and the supernatant is passed in and out of water pool for further treatment.
The novel process for removing fluorine from coking wastewater after biochemical treatment comprises the following steps of:
1. chemical precipitation: and (3) adding a defluorinating agent (mainly calcium hydroxide) into the secondary sedimentation tank or the water outlet pipeline after secondary sedimentation, stirring, and carrying out chemical reaction for 15-20 min.
2. Coagulation: adding aluminum salt into the defluorination tank, stirring, and adding Al in the coking wastewater 3 Hydrolysis in water, and reaction with fluorine ion to produce hydroxy aluminum fluoride complex precipitate and aluminum salt hydrolysis intermediate. Al (Al) 3 +→Al(OH) 3 The alum blossom can perform coordination exchange, physical adsorption and net capture on fluoride ions.
3. Flocculation: adding Polyacrylamide (PAM) as coagulant aid, stirring to make colloid and dispersed particles of suspended matter formed by chemical reaction and coagulation reaction produce floccule under the mutual action of molecular force, and in the course of sedimentation, they are mutually collided and coagulated, and their size and mass are continuously enlarged so as to accelerate precipitation.
4. And (3) precipitation: the time is 1.0-1.5 h.
The addition amount of the calcium hydroxide is as follows: the molar ratio of Ca/F is 1.2-1.6: 1, the Ca/F is small at low temperature and large at high temperature.
The coagulant aluminum salt in the coagulation is mainly but not limited to polyaluminium chloride and polyaluminium sulfate, and the adding amount is as follows: 1-5 kg coagulant/m 3 COD is required to be inspected when coagulant is added to the coking wastewater.
And (4) flocculation, namely determining whether a flocculating agent (PAM) is added or not according to the subsequent treatment of the coking wastewater and the engineering requirements of the coagulated water quality.
A separating device, a coagulant and a flocculant dosing system are arranged in the sedimentation tank.
Compared with the prior art, the invention has the beneficial effects that: 1. the novel process for removing fluorine from the coking wastewater after biochemical treatment is simple, does not influence the subsequent treatment of the coking wastewater, and has auxiliary removal effect on indexes such as COD (chemical oxygen demand), hardness and the like of the wastewater. 2. The effluent after biochemical treatment is not required to be subjected to defluorination pretreatment, the defluorination reagent is directly added into the effluent of the secondary sedimentation tank or the secondary sedimentation tank, and the defluorination effect is enhanced by utilizing the rolling and sweeping and adsorption effects of the residual sludge. 3. The concentration of calcium hydroxide added in the process is controlled to be 1.2-1.6 times of that of fluoride ions, so that the using amount of a calcium agent is effectively reduced, the fluorine removal cost is reduced, and the hardness of the coking wastewater subsequent treatment can be effectively controlled.
A new defluorinating process for biochemically treating coking waste water features that a defluorinating agent (a stirrer is needed for preventing the deposition of calcium hydroxide in chemical tank) whose concentration is calcium hydroxide is used as main component is arranged in defluorinating agent tank according to the flow rate and concentration of biochemically treated coking waste water, and the defluorinating agent is added to defluorinating reactor according to the calcium-fluorine ratio to form granular precipitate in defluorinating reactor in the form of insoluble precipitate of fluorine ions, which is then fed to PAC reactor (coagulating reactor, PAC is aluminium salt), so treating the fluorine ions in secondary reactor with high efficiency and low consumption. Wherein: controlling the adding concentration of calcium hydroxide to be fluorineThe ion concentration is 1.2-1.6 times, and the reaction time is 15-20 min. PAC adding amount of 1-5 kg coagulant/m 3 Coking wastewater, wherein the reaction time is 15-20 min; polyaluminium chloride is a water purifying material, an inorganic polymer coagulant, also called polyaluminium for short, and is called PAC for short, and is an inorganic polymer water treatment agent with large molecular weight and high charge, which is produced by the bridging action of hydroxide ions and the polymerization action of polyvalent anions. The shape of the product can be divided into solid and liquid.
And PAM is determined whether to be added according to the quality of effluent after the coking wastewater is biochemical and the engineering requirements. The precipitation time is 1.0-1.5 h.
The novel process for removing fluorine after biochemical treatment of coking wastewater has the effect of removing COD without increasing the hardness.
Specific example 1:
the method and the laboratory process flow device are adopted to treat the biochemical effluent of the coking wastewater, the water sample comes from a secondary sedimentation tank of a coking wastewater treatment system of a certain coking plant in Anshan mountain, the treatment time is 10 hours, and the water quality indexes of the water sample inlet and outlet are shown in Table 1.
Table 1 water quality index of inlet and outlet water, unit: mg/L
| Index (I) | COD Cr | F- | pH | Conductivity (ms/cm) | Total hardness (as CaCO) 3 Meter) |
| Inflow water | 130 | 42.7 | 8.3 | 5.6 | 167 |
| Discharging water | 65-70 | 18.9-19.4 | 9.7-10.1 | 6.5-6.7 | 92-95 |
Table 1 shows that the quality of the inlet and outlet water shows that the secondary sedimentation tank has stable fluorine removal effect, the fluorine ion removal effect is stable, the removal rate reaches 54.6-55.7%, and the requirement of removing fluorine after the coking wastewater is biochemical is met; the removal rate of COD is 46.2% -50%, and the effect reaches the treatment effect of the traditional coagulation process; the hardness also has better removal effect, and the removal rate is 43.1-44.9%. Since the fluorine removing agent is mainly Ca (OH) 2 Therefore, the pH value of the effluent is higher, and PAM is not added in a laboratory. PAM can be considered to be added according to the requirements of subsequent treatment in the engineering operation, Ca (OH) can be reduced 2 The amount of (A) to (B).
Specific example 2:
the coking wastewater is biochemically treated by the method and the laboratory process flow device, the water sample is taken from a secondary sedimentation tank for treating the coking wastewater of a certain coking plant in Anshan mountain, the treatment time is 17 hours, and the water quality indexes of the water sample inlet and outlet water are shown in Table 2.
Table 2 water quality index of inlet and outlet water, unit: mg/L
| Index (I) | CODCr | F- | pH | Conductivity (ms/cm) | Total hardness (as CaCO) 3 Meter) |
| Inflow water | 330 | 44.4 | 8.6 | 4.6 | 184 |
| Discharging water | 140-170 | 17.8-18.9 | 9.8-1.1 | 4.6-4.9 | 100-110 |
Table 2 shows that the quality of the inlet and outlet water shows that the defluorination effect of the secondary sedimentation tank is stable under the condition of different water quality, the removal rate of fluorine ions reaches 57.4% -59.9%, and the defluorination requirement after the biochemical treatment of the coking wastewater is met; the removal rate of COD is 48.5% -57.6%, and the effect reaches the treatment effect of the traditional coagulation process; the hardness also has better removal effect, and the removal rate is 40.2-45.7%.
Those skilled in the art will appreciate that the invention may be practiced without these specific details. It is pointed out here that the above description is helpful for the person skilled in the art to understand the invention, but does not limit the scope of protection of the invention. Any such equivalents, modifications and/or omissions as may be made without departing from the spirit and scope of the invention may be resorted to.
Claims (10)
1. The utility model provides a defluorination system after coking wastewater biochemical treatment for the experimental study of defluorination technology after coking wastewater biochemical treatment, treat that the defluorination water is coking wastewater biochemical treatment unit goes out water or coking wastewater biochemical treatment back two heavy ponds go out water, its characterized in that, including treating the defluorination water holding reservoir, the input port of treating the defluorination water holding reservoir is the import of treating the defluorination water, the output port of treating the defluorination water holding reservoir passes through the input port of water pump connection defluorination reaction tank, the input port of coagulation reaction tank is connected to the output port of defluorination reaction tank, the top of defluorination reaction tank is provided with first agitator, defluorination agent dosing tank is connected to the defluorination reaction tank, the top of coagulation reaction tank is provided with the second agitator, the coagulation reaction tank connects the coagulation dosing tank, the input port of swash plate sedimentation tank is connected to the output port of coagulation reaction tank, the delivery outlet of swash plate sedimentation tank connects the defluorination box, the water outlet tank, the inclined plate sedimentation tank, the coagulation reaction tank and the defluorination reaction tank are respectively connected with a drainage tank.
2. The system for removing fluorine after biochemical treatment of coking wastewater according to claim 1, a filter screen is arranged at the input port of the storage pool of the water to be defluorinated, a first valve is arranged at the bottom of the storage pool of the water to be defluorinated, a second valve is arranged between the storage pool of the water to be defluorinated and the water pump, a flowmeter is arranged between the water pump and the defluorination reaction pool, a third valve is arranged between the flowmeter and the water pump, a pressure gauge is arranged on a pipeline between the third valve and the water pump, the defluorination reaction tank is connected with the defluorination agent dosing tank through a fifth valve, a three-way node is arranged on a communicating pipeline of the defluorination reaction tank and the coagulation reaction tank, and the first channel of the three-way joint is communicated with the output port of the defluorination reaction tank, the second channel is communicated with the input port of the coagulation reaction tank, and the third channel is communicated with the coagulation dosing tank through a sixth valve.
3. The coking wastewater biochemical treatment post-defluorination system according to claim 1, wherein the defluorination reaction tank is connected with the drainage tank through a fourth valve arranged at the bottom of the defluorination reaction tank, the coagulation reaction tank is connected with the drainage tank through a seventh valve arranged at the bottom of the coagulation reaction tank, and the inclined plate sedimentation tank is connected with the drainage tank through an eighth valve arranged at the bottom of the inclined plate sedimentation tank.
4. The biochemical treatment and fluorine removal system for coking wastewater as claimed in claim 1, wherein the bottom of the drainage tank is provided with a tenth valve, and the bottom of the water outlet tank is provided with a ninth valve.
5. The utility model provides a coking wastewater biochemical treatment back defluorination system, a serial communication port, including defluorination reaction tank, the input port of defluorination reaction tank is that two sink ponds go out water and directly link interface or biochemical treatment unit play water and directly link the interface, the output port of defluorination reaction tank is connected and is thoughtlessly congealed the reaction tank, the top of defluorination reaction tank is provided with first agitator, defluorination agent dosing tank is connected to the defluorination reaction tank.
6. The system of claim 5, wherein the defluorination reaction tank is connected with the defluorination agent dosing tank through a fifth valve, a tee joint is arranged on a communication pipeline between the defluorination reaction tank and the coagulation reaction tank, a first channel of the tee joint is communicated with an output port of the defluorination reaction tank, a second channel of the tee joint is communicated with an input port of the coagulation reaction tank, a third channel of the tee joint is communicated with the coagulation dosing tank through a sixth valve, a second stirrer is arranged at the top of the coagulation reaction tank, the output port of the coagulation reaction tank is connected with an input port of a sedimentation tank, and the output port of the sedimentation tank is a subsequent treatment link interface.
7. A defluorination process after biochemical treatment of coking wastewater is characterized in that a defluorination agent is directly added into a secondary sedimentation tank or a defluorination reaction tank without coagulating sedimentation after biochemical treatment of coking wastewater, and the chemical sedimentation, coagulating sedimentation, residual sludge adsorption and rolling sweeping synergistic action of the defluorination agent are comprehensively utilized to simultaneously defluorinate.
8. The process of claim 7, wherein the defluorination reaction comprises insoluble fluorine-containing compounds generated by calcium ions in combination with other inorganic salts to shorten the chemical precipitation time.
9. A defluorination process after biochemical treatment of coking wastewater is characterized by comprising the following steps:
step 1, a secondary sedimentation tank directly connected with a coking wastewater biochemical treatment unit is used as a defluorination reaction tank to directly defluorinate effluent of the coking wastewater biochemical treatment unit, or the defluorination reaction tank is inserted between the secondary sedimentation tank and a coagulation reaction tank to defluorinate effluent of the secondary sedimentation tank after biochemical treatment of the coking wastewater;
step 2, adding a defluorinating agent into the defluorination reaction tank for chemical precipitation, so that fluorine ions in water generate indissolvable fluorine-containing compounds, and then conveying the effluent of the defluorination reaction tank to a coagulation reaction tank;
step 3, adding a coagulant into the coagulation reaction tank, wherein the coagulant comprises aluminum salt, aluminum ions and fluorine ions generate hydroxyl aluminum fluoride complex precipitate and an aluminum salt hydrolysis intermediate product, alum blossom in the aluminum salt hydrolysis intermediate product plays roles in coordination exchange, physical adsorption and net capture on the fluorine ions, and then conveying effluent of the coagulation reaction tank to the precipitation tank;
and 4, conveying the supernatant formed by standing the water in the sedimentation tank to a subsequent treatment link.
10. The biochemical treatment and fluorine removal process for coking wastewater according to claim 9, wherein the fluorine removal agent comprises calcium hydroxide, the aluminum salt is polyaluminum chloride and/or polyaluminum sulfate, and the step 3 comprises adding polyacrylamide PAM to perform flocculation reaction.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2022101908954 | 2022-02-25 | ||
| CN202210190895 | 2022-02-25 |
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| CN114804400A true CN114804400A (en) | 2022-07-29 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202210252389.3A Withdrawn CN114804400A (en) | 2022-02-25 | 2022-03-15 | System and process for removing fluorine after biochemical treatment of coking wastewater |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115594280A (en) * | 2022-11-08 | 2023-01-13 | 苏州淡林环境科技有限公司（Cn） | Pretreatment process of wastewater containing fluorine sulfonate |
| CN117401850A (en) * | 2023-11-01 | 2024-01-16 | 绵阳宏博环保有限公司 | Method for recycling fluorine in fluorine-containing acidic wastewater and application thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10137769A (en) * | 1996-11-11 | 1998-05-26 | Nec Corp | Treatment of fluorine-containing waste water |
| CN104496063A (en) * | 2014-11-17 | 2015-04-08 | 中国石油集团东北炼化工程有限公司吉林设计院 | Method for removing fluorine in wastewater |
| CN210796127U (en) * | 2019-09-29 | 2020-06-19 | 浙江省环境工程有限公司 | Coking wastewater defluorination decoloration advanced treatment system |
-
2022
- 2022-03-15 CN CN202210252389.3A patent/CN114804400A/en not_active Withdrawn
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10137769A (en) * | 1996-11-11 | 1998-05-26 | Nec Corp | Treatment of fluorine-containing waste water |
| CN104496063A (en) * | 2014-11-17 | 2015-04-08 | 中国石油集团东北炼化工程有限公司吉林设计院 | Method for removing fluorine in wastewater |
| CN210796127U (en) * | 2019-09-29 | 2020-06-19 | 浙江省环境工程有限公司 | Coking wastewater defluorination decoloration advanced treatment system |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115594280A (en) * | 2022-11-08 | 2023-01-13 | 苏州淡林环境科技有限公司（Cn） | Pretreatment process of wastewater containing fluorine sulfonate |
| CN117401850A (en) * | 2023-11-01 | 2024-01-16 | 绵阳宏博环保有限公司 | Method for recycling fluorine in fluorine-containing acidic wastewater and application thereof |
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